garav

1

ACKNOWLEGMENT

I attribute my Honours’ in showing my feelings of indebtedness and thankful to Mr. B.S. Bhullar(Head of Training and Placement cell at Baba Banda Singh Bahadur Engineering college,FatehGarh Sahib(Punjab), S. Hari Singh (M.D.) and Mr. Rajiv Kaushal (Head of Training and accounts manager of Preet tractors Industries Pvt. Ltd. )

I am extremely grateful to Er. Gurpreet Singh (Head of Assembly Department), all the supervisors and workers who offered the valuable guidance, assistance, cooperation, and suggestion.

In the last but not the least I express my thanks to all, who directly or indirectly

encourage me to work at shop floor and discussed with me the trick’s to achieve the

goal.

So I thanks to all mighty God who gave me chance to work with such nice personalities.

GAURAVJIT SINGH

Mechanical Engineering

2

CONTENTS

S. No. Text Page No

1. Certificate -

2. Acknowledgement 1

3. Declaration 3

4. Company Profile 4

5. Quality Department 18

6. Differential 40

7. Brakes 47

8. Rear Axle 51

9. Gear Box Assembly 57 10. Rear Cover Assembly 67 11. Engine 73

12. Other Departments 77 13. PROJECTS: 86 13.1 To make Hardness chart of various parts of tractor 87 so that ease in checking the incoming quality of various components

13.2 To implement power steering on the tractor to 93 make the steering simpler and easier.

3

Declaration

I, Gauravjit Singh do hereby solemnly affirm that the project work has been undertaken by me at the” Preet Tractor Pvt. Ltd.", is an original work and that it is not a duplicate or a copy of any other work. I was guided in this project by Gurpreet Singh, and have performed all the required tasks on my own.

Date: January 5, 2009 Gauravjit Singh

4

5

Introduction to company

History of the firm:

In 1980, when the nation needed one type of machine which could harvest

and thresh the crop simultaneously, to reduce the losses beared by the farmers, S. Hari

Singh (M.D. of Preet Agro Pvt. Ltd.) was working on the project in his tractor repair

workshop. After three years of hardship, he was able to establish a small scale unit for

manufacturing harvesting reapers, Threshers, Agriculture parts. Later, his brother

S.Gurcharan Singh (Director) joined him in 1985 and they were able to make a tractor

driven combine in 1986.

The name Preet was established in 1987. The Project for manufacturing

agricultural Tractors was the farmer’s agricultural requirement. Now the M.D of Preet

Tractor is “S.Gurpreet Singh” s/o S. Hari Singh. The development of tractors which

started in house in 2001 was materialized in launching manufacturing activities of

tractors have started in early 2003. A batch of 21 tractors have been tested (On all the

farming operation) through farmers who had the vast experience in agriculture.

6

Products

Today, Preet Agro Industries is the largest manufacturer of self propelled combines,

tractors and harvesters in India. The company produces a wide range of tractors and

combines which are given below: -

1. Tractors

a) Preet 6049

b) Preet 5049

c) Preet 4549

d) Preet 4049

e) Preet 3549

f) Preet 3049

7

1.PRODUCT RANGE FOR TRACTORS

8

9

INFRASTRUCTURE:

PREET is one of the India's leading manufacturers of agricultural tractors and combine harvesters. PREET is market leader in self propelled combine harvesters in India. We are controlling 35% market share of self-propelled combine harvesters.

Present scenario of plant: -

1. Our company is ISO 9001: 2000 certified company.

2. Combine harvesters are manufactured on organized assembly

production line.

3. Plant is equipped with latest CNC turning machines for machining of

components and others computerized machines i.e. shearing

machines, bending press, power press, lathe, shapers and radial drill

machines etc.

4. Company is having one another fully computerized Turret punching

machine to enhance production capacity and to maintain the quality of

product.

Future Plans: -

1. Company has installed Laser oscillator machine from MAZAK Japan.

2. We will be first to install Robots for all type of welding jobs in our plant

in next financial year.

3. Dip Painting of sheet metal will be install soon.

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AWARDS / ACHIEVEMENTS:

The company participated in KISSAN MELA organized by Punjab Agricultural

University Ludhiana in September 2003 and September 2005 with exhibition our

tractors and harvester combine. In the fair all the established manufacturers and

international giants participated we were adjudged the best performer and awarded

the first prize by the organizing authorities.

The company has participated in International Farm Equipment Show held in

Toronto Canada in Feb’06.

Mr. Ron Bollman from Government of Canada Invites “Preet Agro Industries” to

setup their plant in Ontario Canada.

The company has also participated in international trade exhibitions held in Sri

Lanka & South Africa.

The company has also attended the multi-trade visit, in different companies of

United States of America & Canada.

Participated, adjudged the best performer and awarded the first prize in Krishi

Mela 2006 held in University of Agricultural Sciences, Dharwad Karnataka.

11

OBJECTIVES:

PRIMARY OBJECTIVES:

The company has laid down for itself goal of improving the value to the customers

through maintaining leadership in following categories.

Market share: To maintain its status as brand leaders in the country

for combines and tractors.

Product Development: To develop tractors and combines for all new applications as

identified.

Technology modernization and up gradation of technology to the latest

improvements to meet customers requirements.

Customer satisfaction it shall strive to achieve customer satisfaction rating more than

90%.

Quality: To improve quality consistently through quality assurance and process

control.

Delivery to strive to achieve 100% on time.

SECONDARY OBJECTIVES:

To create and distribute a product.

To profit earning.

Protection & security to its workers.

Safety for its workers.

To meet social obligation.

Economy of operation by lowering cost.

Ensure a good quality system.

Training & development of existing work force.

To satisfy customer.

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Better management

Better human relation.

FLOW CHART OF MANUFACTURING PROCESS

Production Planning & Control (PPC)

Purchase Department

Quality Control Department

Stores

Machine Shop

Assembly Shop

Paint Shop

Pre Delivery Inspection (PDI)

Sales Department

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Process of Manufacturing

The process of manufacturing is rather a complex one though it seems to be simple.

Every part to be manufactured undergoes through tests and is used only after the

approval of quality department. The entire manufacturing process is pre decided and is

guided by the recommendations and suggestions of Production Planning & Control

Department (PPC). During manufacturing process, the manufacturer has to follow the

industry standards being established by the industry. After quality control department

o.k. & rejected component send to store. From store o.k. component are send to the

assembly line no.1 and after assembling, the tractors are send to paint shop for

painting. After paint shop all the electrical work is done in the assembly line no.2. Thus,

the manufacturing process is complete after assembly line no.2. Then tractor is send to

PDI (Pre Delivery Inspection) where they are checked for the faults if any. Now, the

tractors are ready to be send to the sales department for sale

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Technical Specifications of Tractors

DESCRIPTION PREET 3549-I PREET 4049-I PREET 4549-I PREET 5049-I PREET 6049-I

ENGINE

Model / Make PREET 3549 PREET 4049 PREET 4549 PREET 5049 PREET 6049

Power (PS) 34 39 45 47 57

Type Four Stroke DI Four Stroke DI Four Stroke DI Four Stroke DI Four Stroke DI

No. of Cylinders

3. Vertical Inline 3. Vertical Inline 3. Vertical Inline 4. Vertical Inline 4. Vertical Inline

Max. Torque136Nm @ 1300

rpm150Nm @ 1300

rpm175.5%Nm @

1300 rpm136Nm @ 1300

rpm183Nm @ 1300 rpm

Bore / Stroke (mm)

95/110 97/110 102/110 95/110 100/110

Rated Engine rpm

2100 2100 2100 2100 2200

Displacement (cc)

2340 2438 2697 3119 3456

Fuel PumpInline Plunger (MICO Bush)

Inline Plunger (MICO Bush)




Air CleanerOil Bath with pre cleaner

Oil Bath with pre cleaner




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Cooling System

Water Cooled Water Cooled Water Cooled Water Cooled Water Cooled

TRANSMISSION

Gear Box8 + 2 Sliding

Mesh 8 + 2 Sliding

Mesh 8 + 2 Sliding

Mesh 8 + 2 Sliding

Mesh 8 + 2 Sliding Mesh

ClutchHeavy Duty Dry Single 280 mm

Heavy Duty Dry Single 280 mm




BreaksMulti Disc Dry Type Mech.

Multi Disc Dry Type Mech.




ROAD SPEED Km/Hr

Gear LOW HIGH LOW HIGH LOW HIGH LOW HIGH LOW HIGH

1 2.51 9.87 2.51 9.87 2.51 9.87 2.57 10.1 2.37 10.88

2 3.30 12.98 3.30 12.98 3.30 12.98 3.38 13.28 3.64 14.30

3 5.12 20.13 5.12 20.13 5.12 20.13 5.24 20.6 5.64 22.18

4 8.08 31.8 8.08 31.8 8.08 31.8 8.27 32.54 8.90 35.04

Reverse 3.51 13.8 3.51 13.8 3.51 13.8 3.59 14.12 3.87 15.21

STEERING

Type 2 Lever, ADDC 2 Lever, ADDC 2 Lever, ADDC 2 Lever, ADDC 2 Lever, ADDC

Hydraulic Pump

Gear Type Gear Type Gear Type Gear Type Gear Type

Linkage3 Point Linkage

- II3 Point

Linkage - II3 Point

Linkage - II3 Point

Linkage - II3 Point

Linkage - II

POWER TAKE OFF

Splines 21 21 21 21 21

P.T.O. Speed 1000 1000 1000 1000 1000

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CAPACITIES (Liters)

Fuel Tank 48 48 56 56 56

Engine Sump 8 8 8 10 10

Cooling Systems

8.5 8.5 8.5 9.5 9.5

Air Cleaner 0.75 0.75 0.75 1 1

Transmission & Hydraulic

55 55 55 55 55

Steering 0.5 0.5 0.5 0.5 0.5

TYRE SIZE

Front 6.00x16 6.00x16 6.00x16 6.00x16 7.50x16

Rear 13.6x28 13.6x28 13.6x28 14.9x28 16.9x28

Weight (Kgs) 1945 1945 1945 1945 2170

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Definition of Tractor

A tractor is a vehicle specifically designed to deliver a high tractive effort at slow

speeds, for the purposes of hauling a trailer or machinery used in agriculture or

construction. Most commonly, the term is used to describe the distinctive farm vehicle:

agricultural implements may be towed behind or mounted on the tractor, and the tractor

may also provide a source of power if the implement is mechanized. Another common

use of the term is for the power unit of a semi-trailer truck.

The word tractor was taken from Latin, being the agent noun of trahere "to pull". The

first recorded use of the word meaning "an engine or vehicle for pulling wagons or

ploughs" occurred in 1901, from the earlier term traction engine (1859).

The first tractors were steam-powered ploughing engines. They were used in pairs

either side of a field to haul a plough back and forth between them using a wire cable.

History of Tractor

In 1889 first time a tractor manufactured by a company in which internal

combustion engine was used. The first demonstration of tractor was shown in 1910-

1914. In 1915-1919 first time P.T.O added into the tractor. In 1930-1937 all electricity

works tyres and diesel engine used in the tractor. In 1937-1941 three point hitch system

attached with tractor. In 1950-1960 so many tractor manufactured which was have

higher horse power as compared to previous tractors.

http://en.wikipedia.org/wiki/Vehicle

http://en.wikipedia.org/wiki/Ploughing_engine

http://en.wikipedia.org/wiki/Traction_engine

http://en.wikipedia.org/wiki/Agent_(grammar)

http://en.wikipedia.org/wiki/Latin

http://en.wikipedia.org/wiki/Semi-trailer_truck

http://en.wikipedia.org/wiki/Farm_equipment

http://en.wikipedia.org/wiki/Farm

http://en.wikipedia.org/wiki/Construction

http://en.wikipedia.org/wiki/Agriculture

http://en.wikipedia.org/wiki/Trailer_(vehicle)

http://en.wikipedia.org/wiki/Tractive_effort

18

19

INTRODUCTION

TO

INCOMING QUALITY CONTROL DEPARTMENT

(IQC)

Preet Tractor Ltd. Is making a wide variety of tractors which is being sent to

National & International market .Quality is the main & important thing of this industry to

sell there tractors.

Incoming Quality Control is a department at preet tractor ltd. which checks

the quality of the components being purchased from the different vendors, which are

used in the assembly of the tractors. These components are checked with very close

quality control on every parameter with the help of state-of-the-art quality control and

inspection equipments.

MEANING AND NEED OF QUALITY AND QUALITY CONTROL

Quality is one of the important factors which influences the purchaser of product

and helps to capture market. It plays an important role in customer‘s decision and

which is why control of quality during manufacture of a product is very necessary.

Quality in simple words is defined as the fitness for use. An equally good

definition is conformance to requirements. In both the above definitions, quality is

defined relative to use, rather than as a general characteristic that may be

intangible. By this simple, yet practical definition, if a product or service lives up

20

to expectations, it is of high quality. On the other hand, extra fine finish or using

materials that are far stronger than required does NOT add quality to an item

unless it somehow causes the item to conform to its requirement better.

Quality of product depends upon the application of materials, men, machines

and manufacturing conditions. The systematic control of these factors is the quality

control. The quality of a product differs greatly due to these factors. For example, a

skilled worker will produce products of better quality and a less skilled worker will

produce poor quality products. Similarly better machines and better materials with

satisfactory manufacturing conditions produce a better quality product. Thus it is

clear that to control the quality of product; the various factors which are

responsible for quality are required to be controlled properly.

It may also be defined as “Quality control is an effecting system for

integrating the quality development, quality maintenance and quality

improvement efforts of various groups in an organization so as to enable

production and service, at the most economic levels which allow for full

customer satisfaction”. In other words, quality is everybody’s business and not

only the duty of the persons in the Inspection Department.

NEED: The quality control is needed due to the following reasons:

a) Customer’s Satisfaction

b) Economy

c) Reduction in Scrap

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BENEFITS OF QUALITY CONTROL

There are many advantages by controlling the product quality. Some of them are

listed below:

a) Improvement in quality.

b) Increased production under same set up.

c) Reduction in cost due to lower rejection and reworking.

d) Reduction in scrap.

e) Reduction in production bottlenecks.

f) Reduction in inspection in terms manpower and equipment cost.

g) Evaluation of quality tolerance with an idea of avoiding uncalled for quality

build-up.

h) Maintenance of operating efficiency.

i) Less customer complaints.

j) Quality consciousness.

In IQC Department Incoming Raw Material are inspected in order to:

Eliminate those material which do not meet specification and likely to cause

trouble during processing.

Evaluate vendor’s quality and ability to supply acceptable materials.

Inspection of raw material may involve a visuals check up only, a

dimensional check, a test of physical properties and chemicals

composition, etc.

Raw materials depending upon their characteristics and may require a

sampling inspection

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After inspection, the right quality parts are sent either to stock room or

Assembly lines.

Hence Incoming Quality Control department helps to maintain the standard of the

tractors being assembled in International tractor Ltd.

QUALITY RESPONSIBILITIES:-

AS A USER:-

Transmit needs to supplier.

Provide feed back to supplier

Obtain feed back from supplier

AS A PROCESSOR:-

Plan process to meet customers need.

Control process to meet customers need.

Improve process based on customers feed back.

AS A SUPPLIER:-

Know who are customers

Understand the needs of customers.

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Avoid creating problems for customers

Obtain feed back from customers.

TESTING PROCEDURE OF THE COMPONENTS

The components are tested by the following procedure:-

1) APPEARANCE

2) DIMENSIONS

3) WEIGHT

4) FITMENT

5) FUNCTION/PERFORMANCE

6) MATERIAL

7) PROCESS

8) WELDING CHECKING

1) APPERANCE: -

It is the first step to checking appearance of the components means how the

component looks like. Whether its surface is smooth or not? Whether its sharp edges

are chamfered or not? In this step component welding, surface treatment and machining

is also checked.

2) DIMENSIONS: -

It is the most important step of the quality testing of the various components. The

dimensioning means the checking of the dimensions of the component, whether these

are correct or not? The dimensioning is done by certain instruments like the VERNIER

CALLIPER, MICROMETER, BEVEL PROTECTOR, HEIGHT GAUGE, etc. By these

24

measuring instruments the measurement of the dimensions of the component become

very easy. These dimensions are checked with respect to the dimensions given in the

drawing i.e. the required dimensions.

3) WEIGHT: -

The material of component is also necessary because it gives idea of the material

required for manufacture the component. The weight of the component is measured by

weighing machine. This machine can measure the weight from 500gram to 50000gram.

There is scale on the measuring machine, which shows the reading of the weight.

4) FITMENT: -

Fitment means fitting of the component actually in the vehicle. The component is

then checked whether it fit properly in the relevant position or not. If the component is

fitted properly and then component get accepted otherwise it rejected. So the

acceptation or rejection of the component is also based upon the fitment of the

component.

5) FUNCTIONAL PERFORMANCE: -

The functional performance of the component is measured after the fitment of the

component. Functional performance means how well the component is functioning in

the vehicle.

6) MATERIAL: -

The material of the component should be able to absorb the stresses produced in

that component. The material may be brittle, hard or tensile as per requirement.

Hardness of the material is generally checked by Rockwell hardness testing machine,

poldi hardness tester and shore hardness tester.

7) PROCESS: -

In this step of the quality control of the components the processes of the

components are checked. For making a certain component there are certain processes

25

by which a component should go through. These processes are made in serial wise and

the component should follow these processes in serial wise. If the processes are serial

wise then component is made exactly according to our requirement. These processes

can be checked only at the production site i.e. where the component is manufactured.

So in case of our industry the processes can only be checked on the vendor side where

the component is manufactured. The processes can be drilling, punching, tapering,

lathing, heat treatment, machining etc.

8) WELDING CHECKING: -

Welding checking is also an important process in the quality testing of the different

components. It is mean that checking of strength of welding portion. The components

are made of different parts, which are welded with each other to make the suitable and

complete component. So it is very necessary to check the strength of the welding, in

order to maintain strength and quality of the component. Here mainly blow holes,

porosity; welding appearance etc of the welded component is checked.

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QUALITY IMPROVEMENT SYSTEMS

1. COMPONENT DRAWINGS.

2. PROCESS SHEET WITH SUMMERY SHEET. (REF. SCD PROCESS SHEETS).

3. FIRST PC. SETTING OK RECORD

4. RUN CHART FILLING BY OPERATOR & AUDIT BY QE ON RUN CHART.

5. CHECKLIST ON FRONT SIDE & PDI ON THE BACKSIDE OF THE SHEET.

6. IN PLANT REJECTION & THERE DEFECT ANALYSIS.

7. PERIODIC INSPECTION AND MAINTENANCE OF TOOLS/GAUGES &

MACHINES.

8. MASTER SAMPLE SHOULD BE AVAILABLE FOR EACH SHEET.

9. MATERIAL SHOULD BE PROPERLY STACKED IN BINS .(NO MATERIAL

SHOULD BE ON SHOP FLOOR)

10. TOOLS & GAUGES SHOULD BE KEPT PROPERLY AT THEIR ENMARKED

PLACE.

11. WORKSTATION SHOULD BE ACCORDING TO LAYOUT PLAN.

12. MATERIAL SHOULD BE TRANSPORTED TO PTL IN BINS & ARRANGEMENT

SHOULD BE AVAILABLE FOR LODING BINS INTO LCVs.

13. THE RESPONSIBILITY OF IMPLEMENTING AND MAINTAINING THE

VERIOUS RECORDS SHOULD BE CLEARLY DEFINED AND THE NAME OF

THE PERSON TO BE INTIMATED TO VDC AND BUY.

14. SUBMISSION OF SELF-APPRAISAL FORM.

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HARDWARE SECTION

Hardware is one of the main sections of the Incoming Quality Control Department.

All the hardware items which are used in the tractor assembly are checked

thoroughly in this section of IQC department. There are more than 900 different

components which are checked on regular basis, for this purpose Quality Inspectors

are provided with the entire measuring Instrument required by them.

For the convenience these components are further categorized under different

groups .Name of such groups is as follows:-

WASHERS:- There are 96 types of different WASHERS which are

checked under this group. All these are used in different tractor

assemblies.

SHIMS: - There are 75 types of different SHIMS which are checked under this

group. All these are used in different tractor assemblies

BOLTS & SCREWS: - There are 60 types of different BOLTS & SCREWS

which are checked under this group. All these are used in different tractor

assemblies

RUBBER ITEMS: - There are 80 types of different RUBBER ITEMS which

are checked under this group. All these are used in different tractor

assemblies.

SPRINGS: - There are 50 types of different SPRINGS which are checked

under this group. All these are used in different tractor assemblies.

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DELIVERY & FUEL PIPES: - There are 54 types of different DELIVERY &

FUEL PIPES which are checked under this group. All these are used in

different tractor assemblies.

SUCTION PIPES: - There are 54 types of different SUCTION PIPES


assemblies.

KNOBS: - There are 21 types of different KNOBS which are checked


PLUGS: - There are 21 types of different PLUGS which are checked


O-RINGS &SEALING RINGS: - There are 20types of different O-RINGS

&SEALING RINGS which are checked under this group. All these are

used in different tractor assemblies.

CLAMPS: - There are 23 types of different CLAMPS which are checked


HOSE PIPES: - There are 18 types of different HOSE PIPES which are


assemblies.

DUST CAP PTO COVER: - There are20 types of different DUST CAP

PTO COVER which are checked under this group. All these are used in

different tractor assemblies.

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BUSHES: - There are58 types of different BUSHES which are checked


WIRE & CABLES: - There are 23 types of different WIRE & CABLES


assemblies.

PINS: - There are 120types of different PINS WASHERS which are


assemblies.

NUTS: - There are 14 types of different NUTS which are checked under

this group. All these are used in different tractor assemblies.

ADOPTERS: - There are 13 types of different ADOPTERS which are


assemblies.

SPACERS: - There are 65 types of different SPACERS which are


assemblies.

GASKETS: - There are 66 types of different GASKETS which are


assemblies.

FUEL CUT OFF RODS: - There are 6 types of different FUEL CUT OFF

ROD which are checked under this group. All these are used in different

tractor assemblies.

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Flow chart for quality process

Material receiving report

Sampling as per IS 2500

Checking as per quality plan

O.K. Result not ok

Send to store passes under deviation

In process rejection

Quality rating

Monthly rejection report information sends to purchase department

Analysis of rejections

Monthly performance trends

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List of instruments used into IQC department

S.NO. NAME OF INSTRUMENT RANGE MAKE QTY.

1 VERNIER CALLIPER 0 - 600mm MITUTOYO 1



4 DIAL INDICATOR 0 - 11mm MITUTOYO 3

5 DIAL INDICATOR - MITUTOYO 1

6 MICROMETER 0 - 25mm MITUTOYO 1







13 FLANGE MICROMETER 0 - 25mm MITUTOYO 1






19 SLIP GAUGE BOX 83PC. PECOCK 1

20 RADIUS GAUGE 1 - 7mm MITUTOYO 1

21 RADIUS GAUGE 7.5 - 15mm MITUTOYO 1

22 RADIUS GAUGE 15 - 25mm MITUTOYO 1

23 FEELER GAUGE 0.05 - 1.00 ATUL 1

24 HEIGHT GAUGE(DIGITAL) 0 - 600 MITUTOYO 1

32

25

ROCKWELL HARDNES

TESTER - FINE 1

26

SHORE HARDNESS

TESTER 0 - 100 MITUTOYO 1

27 DIAL BORE GAUGE 10 - 18.5 MITUTOYO 1

28 DIAL BORE GAUGE 18 - 35 MITUTOYO 1



31 MEGNETIC STAND - - 1

32 MICROMETER STAND MS - 1 - 1

33 MAGNETIC V - BLOCK 102X96X72 SAMRT 1

34 MAGNETIC V - BLOCK 152X98X74 SAMRT 1

35 THREAD PITCH GAUGE B.S.W. MITUTOYO 1

36 SPECIAL DEAD CENTRE -

BHAL

ENGG. 1

37 SCREW JACK (BIG) - - 4

38 SCREW JACK (SMALL) - - 4

39 BED CENTRE 1000X260 LUTHRA 1

40

SURFACE PLATE

(GRANITE) 1000X1000 LUTHRA 1

41 CYLINDRICAL PINS ø 3.1 - 5









33

50 THREAD RING GAUGE M24X1.5 HIP 1





55 THREAD RING GAUGE M16X2 HIP 1







62 THREAD PLUG GAUGE M24X1.5 HIP 1





67 THREAD PLUG GAUGE M16X2 HIP 1







74 CALCULTOR SCIENTIFIC - CASIO 1

75 GEAR PROFILE TEATER MITUTOYO 1

Poldi hardness tester

34

Direction of use

This poldi hardness tester is use to find out the brinell number of the

component. First of all insert the tapered end of the standard test bar after cleaning into

the space provided between the ball and plunger and slide it further beyond the tapered

portion. The test bar will thus firmly grip between the ball and plunger pressed by the

spring. The specimen to be tested should be properly ground or filed and polished at the

surface where it is to be tested to ensure accurate reading. With standard test bar

inserted place the tester vertically or the specimen such that the ball touches the

polished surface. Give a blow on the top of the plunger, with a hammer. The blow

should not be very hard and should be as vertical as possible.

The blow will cause two indentations one on the standard test bar and the

other on the specimen. The diameters of these two indentations should be measured

accurately with magnifier having least count of 0.1 mm provided with the machine. If the

indentation so obtained is slightly elliptical, average diameter should found out. The

distance between the centres of any two indentations on the standard test bar should be

less then 1.5 mm. If the bar is fully utilized it has to be replaced. The limiting indentation

diameter on the standard test bar is 4.2 mm.

The tensile strength and brinell hardness number of various metals can be

found as under.

Steel: - the booklet contains two tables one for steel in natural or annealed state and

the other for steel in hardened or tempered state. It is necessary to know the condition

of specimen before and if however it is not know or cannot be determined than first the

table is for natural or annealed steel be used for specimen having Brinell hardness

number up to 360. When the hardness of the specimen exceed 360 the other are to be

used.

Other metals: - separate tables have been provided for other metals example brass,

copper, bronze and cast iron. These tables do not show the tensile strength of these

metals but only the Brinell hardness number because the relation between the Brinell

35

hardness and the corresponding tensile strength has not yet been established with as

much reliability as in the case of steels.

Procedure

After measuring the actual diameter of indentation on standard test bar the

column diameter of indentation on standard bar should be referred for the same value

and for the actual diameter of indentation on work piece the row diameter of indentation.

On work piece should be referred where the horizontal and vertical columns intersects

the tensile strength in tonnes per square in and the Brinell hardness number can be

read. To convert the tensile strength from tonne/sq. In to kg. /sq. mm uses a multiplying

factor of 1.575.

To take core of the variations in the tensile strength and the hardness of

standard test bar is properly tested and a multiplying factor is inscribed on it, at the end.

For determine the exact tensile strength and hardness of specimen,

multiply the reading found from the table by this multiply factor.

Example: - diameter of ball indentation

1 on the test bar 1.8mm

2 on the specimen 1.7mm

Tensile strength found from table after conversion 80kg/sq. mm. Brinell hardness

number found from table is 223 BHN. Multiplying factor inscribed on standard test bar

1.03. Therefore, the tensile strength of specimen is 80*1.03 = 82.4 kg/sq. mm in and the

Brinell hardness 225*1.03 = 235.8 BHN. When after some use the protruding end of the

plunger gets deformed by blows it may be reconditioned and rounded off or simply

replaced.

Poldi type impact hardness tester is not designed to replace the tensile

strength hardness machine and standard hardness tester. The accuracy of this

hardness tester may be very times to the extent of 10% as against the more accurate

table type standard hardness tester. However the poldi impact hardness tester has the

advantage of easy handling and greater flexibility. This is very important, specially for

testing heavy specimen which cannot be taken to a table type hardness tester are

extremely costly compared to poldi tester and require greater skill to operated properly.

36

Gear Roll Tester

It is hand operated bell crank lever type. First of all we will study about introduction.

Introduction

1 Gear roll tester is a simple workshop gear rolling facility, designed to

measure double flank error of smaller component gear meshing with its master.

2 The result indicated size, hence backlash, run out, tooth damage and

some, ensure of individual tooth quality.

3 The tester is robust intended for workshop use where it may be placed

next to gear generating machine or on the production line.

Principle of operation

1. Component gear is rolled against its master gear of suitable quality,

under positive spring load ensuring (zero backlash double flank contact).

2. Master gear mounted on spring loaded bell crank lever and component

gear is mounted on fixer saddle clamped at designed centre distance.

3 Change in centre distance as gear is rolled together cause bell crank to

respond, which is registered on suitable dial indicator. The element measured or which

can be deduced from the results are as follows.

Size and backlash

If component gear is oversize, its close mesh centre distance will be

greater than designed and will be reflected in dial indicator readings. An oversize gear

will have a reduced backlash, resulting in tightly running, overheating excessive noise

and possible physical damage. An under size component gear will recorded lower than

desired dial indicator readings, will have more than desired backlash, which in turn may

cause loss of tooth strength excessive noise on reversed and changed pressure angle

reducing transmission efficiency.

Eccentricity

Continuous measure of effective centre distance during rolling is indicated

as geared rotated. Run out is TIR (excluding localized defects registered as sudden

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flicks or kicks) on dial indicator. Run out will cause transmission errors and noise, and

may cause harmful backlash either two great or two small.

Composite errors

Centre distance between gear under roll change as each pair of teeth

move into and out of contact. The change is registered on dial indicator. This is known

as “tooth to tooth composite error”. Total composite error is difference between

minimum and maximum reading on dial indicator.

Damage

Sharp flicker on dial indicator is generally caused by some localized

defects viz. bruising, raised burn or dent on tooth profile. Zero backlash double flank roll

test between component gear and its master is the quickest and satisfactory method to

determine all the above 4 parameters, in a single pass having tome and cost.

Advantage of the test

The rolling testing offers considered technical advantage mainly.

1 Composite error is often specified by national and international standard

and therefore often common base for comparison.

2 The test is very simple and does not require skilled operated.

3 It is very fast, required negligible setting time, therefore very economical.

4 The test covers both the flank of every tooth and detects damage; even

through tooth from cannot be directly measured. It is therefore very through.

5 It is most convenient and effective way of measuring size and backlash.

Construction features

Bell crank lever mechanism is essentially a mechanism having a bell

crank with fully protected pivot and it is placed inside the gear roll tester. Harder block is

on one arm of the bell crank and dial actuating pin is on the other arm. On the harder

block provision is made for the mounting mandrel for master gear. Distance of master

gear and dial actuating pin from pivoted centre line are exactly some and hence it

indicates exact deviation of the gear. A tension spring is used to maintain correct load

for component and master gear engagement. This spring force is calibrated before the

dispatch of the gear roll tester. Fixed saddle provided on the other side of bell crank

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lever the main body. Component gear mandrel is mounted on the ground pad on this,

which is made flat and parallel to master gear mandrel mounting face on bell crank

mechanism. This fixed slide on the scraped bed of main body has two tendon slots

which have four holes to clamp fixed saddle in requisite position by tighten four dome

nuts.

The fixed saddle is to be moved only during setting of specified centre

distance for different gears. During test fixed saddle must be properly clamped by

tightening four dome nuts.

Method of operation

1 This merely involves adjusting vertical level of both gear and setting

centre distance to the required datum using gauge block or special setting discs.

2 Bell crank lever is with drawn to disengage position. Component gear is

mounted and engaged with its master.

3 It is usual to load component gear on fixed saddle, as it is clamped on

the main body. If heavy component gear is mounted on sensitive bell crank lever it may

damper free sensitive movement.

4 Component gear is located on suitable mandrel if necessary, on fixed

saddle in fixed position and in then rotated until component gear completes one

complete rotation. During this time, TTCE and maximum and minimum dial indicator

readings are observed; with special attention to sudden flickers.

Capacity

1 Maximum centre distance between mandrel is 260 mm.

2 Standard equipments: - gear roll tester with fixed saddle with bell crank

mechanism, having master mandrel faces fitted with dial indicator having least count .01

mm capacity 10 mm.

Accessories

1 Sliding bracket with vertical column to accommodate mandrel/ gear of

length 100 to 500 mm provided.

2 Baker make dial gauge 0 to 10 mm provided.

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Operating Instructions

1 Using engagement/disengagement lever confirms bell crank lever

movement is free and smooth.

2 Mount master and component gear mandrel on their respective

mounting faces after cleaning the mating faces properly. Tommy is provided to tighten

the mandrel.

3 Place PCD discs of master and component on respective mandrels

4 Loosen 4 nos. dome nuts on fixed saddle and move it gently to fro, as

required, till both PCD discs touch each other when bell crank lever is in engaged

position.

5 Reposition fixed saddle to adjust required pre load on dial indicator.

Clamp the four dome nuts on fixed saddle to fix position and desired meshing centre

distance. Set zero on dial indicator. Repeats engage disengage movement to ensure

that set zero is repeated.

6 Retract engagement lever to disengagement position remove PCD

disks. In obscene of PCD links, requisite desired centre distance can be set by means

of suitably slip gauge blocks.

7 Locate master and component gear on their locating mandrels. Now the

tester is ready for checking component gears. Put engagement lever to engage

position, thereby meshing component and master gear with a positive and constant

spring load pressure, to give double flank contact.

8 Rotate the component gear manually. A minimum of one revolution of

the component gear has to be completed observe dial indicator reading, which can be

interpreted for PCD variation, PCD run out, high spots caused by dent burr etc.

9 Disengage master gear by retracting bell crank lever. Remove

component gear under test.

10 For checking similar component gears repeat the above steps.

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41

Differential

If a tractor travels in a straight line, the two rear wheels turn on the road

exactly at the same speed. There is no relative movement between the rear wheels. But

when the tractor takes a turn, the outer wheel travels on a longer radius than the inner

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wheel. The outer wheel turns faster than the inner wheel, that is, there is a relative

movement b/w the two rear wheels. If the two rear wheels are rigidly fixed to a rear axle

the inner wheel will slip which will cause rapid tyre wear, steering difficulties and poor

road holding. Therefore, there must be some devices to provide relative movement to

the two rear wheels when the tractor is taking a turn. The differential serves this

purpose.

Differential is a part of the inner rear axle housing assy., which includes the

differential, rear axles, wheels and bearings. The differential consists of a system of

gears arranged in such a way that connects the intermittent shaft with the rear axles.

The purpose of the differential is to provide the relative movement to the two rear

wheels when the tractor is taking a turn. The torque transmitted to each wheel is,

however, always equal.

Construction: - Fig. shows the construction of a simple differential. In this

case cage assembly is made by four bevel gears. On the cage assembly crown wheel is

mounted. This crown wheel is attached with the tail pinion gear. Cage assembly is

hollow from both sides. In this space two bull pinion shafts are attached. These shafts

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help to transmit relative motion when tractor takes turn. This bull shaft further attached

with bull gear which is mounted on the rear axles. Now we learn about how power is

transmitted from when tractor moves in straight position and when it takes turn. When

tractor moves in straight position then power transmitted from tail pinion to crown wheel.

When crown wheel rotates then whole cage assembly rotates but its internal gears of

cage assembly remains constant. From crown wheel power transmits to bull pinion shaft

and further to bull shaft. But when tractor takes turn then relative motion produces

between the tyres due to these internal gears of cage assembly rotates. This relative

cause is to give the different speed ratio to the rear wheels. This way it works.

Scoop lock set is also mounted on the cage assembly. It plays a great roll

in cage assembly. Every body knows very well that every gear needs lubrication for long

life. Scoop lock is doing same work here. When cage assembly rotates with high speed

then one layer is become on the outer surface of the cage assembly. Due to that

lubricant does not enter into the cage assembly. Scoop lock destroys this outer layer of

lubricant means this scoop help to lubricant to reach into the cage assembly.

Cage assembly

1 Bevel gear

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2 Thrust roller bearings

3 Cross

4 Thrust washers

5 Spider kit

6 Scoop lock

7 B.P. shafts

CAGE ASSEMBLY

Technical condition for differential

Pre loading of tail pinion

Pre loading means load required to rotate tail pinion with easy way. It is very

necessary part when we assemble the tractor. It we did not check this then some

problem would create. If pre load is less then it may rotate at a high speed which will

45

cause of damage of teeth’s. If pre load is greater then required then more wear will

occurs. Generally pre load for tail pinion is 6 kg to 8 kg.

Pre loading of crown wheel

For crown wheel it is generally 10 kg to 12 kg.

Backlash

It is the difference between the tooth space and the tooth thickness space, as

measured on the pitch circle. It is also very important term. If we did not check the

backlash during assembly of differential than it may cause of some damages.

Between the tail pinion and crown wheel it is generally .25 to .35 mm.

If backlash is less or greater than required then it makes correct with the help of

packing material or shims. If backlash is less then range than packing material or shims

transfer from left to right. If backlash is greater then range than packing material or

shims transfer from right to left.

Pattern

It is percentage of surface area which come contact between the two

meetings tooths. It should be more then 50%.

Lapping

It is a process in which one pair of tail pinion and crown wheel prepared.

In this process pinion teeth’s makes mark on the crown wheel teeth’s. This way one set

is prepared. If we use two different pair in one assembly than it would creates some

problems.

Differential Trouble Shooting

1. Noisy Differential :

(a) Less lubricating oil in the differential housing.

(b) Low viscosity oil or use of quality oil.

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(c) Wrong adjustment of crown wheel and pinion teeth.

(d) Wrong out hub bearing.

(e) Worn out or broken teeth of crown wheel or pinion.

(f) Less in backlash in crown wheel and pinion teeth.

(g) Worn out bearing of crown wheel or pinion.

(h) Crown wheel misaligned on cage.

(i) Loose star pinion.

(j) Broken or worn out thrust washers of pinion or sun pinion.

2. Vehicle does not move when put in gear :

(a) Broken propeller shaft.

(b) Broken axle shaft.

(c) Broken pinion flange key.

(d) Broken teeth of crown wheel and pinion.

(e) Broken cross or star pinion.

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48

Introduction

The vehicle had been started, accelerated and was running on the road. It

is now to be stopped. Stopping of the vehicle is as necessary as it starting. Once the

vehicle is started, it must be stopped somewhere. Brakes are applied on the wheels to

stop the vehicle. Before applying the brakes , the acceleration is released to stop the

fuel supply thus the engine develops no more power to run the vehicle, and then the

brake are applied which stop the rolling of the wheels on the road and hence the vehicle

is stopped.

Functions of the brakes

There are two distinct functions of the brakes.

1 To stop or slow down the vehicle in the shortest possible distance in

emergencies.

2 To control the vehicle to be retained when descending a hill.

The first function calls for the brakes which can apply large braking

torques to the brake drum, while the second calls for brakes that can dissipate large

quantities of heat without large temperature rises.

Brake assembly parts

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1 Brake disk

2 Brake link

3 Brake actuator fork

4 Brake boot

5 Brake lever

6 Brake tie road

7 Brake liner having diameter 7.5 inches

8 vent breather

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Construction and working of the brake

Brakes used into the tractor are Mechanical brakes. First of all in the brake

housing put one ne brake liner and than on that brake disc put into. This brake disc

make with five springs which help it to remain its position when brake foot lever

released. On the other face of brake disc also one brake liner attached. When brake

actuate than one brake liner produce friction with the differential face and second brake

liner produce friction with brake housing face. Assemble two brake links with the brake

disc. After that brake fork attached with the brake links and than brake lever and tie road

assembled. This tie road is used to adjust the length. When we press the brake foot

lever than through the attached link power transmitted to tie road. This tie road pulls the

fork and lever. Then power transmitted to brakes links. These brake links pull both ends

of the brake disk. When both ends of brake links pulls into each other than balls which

are adjust into the gap of brake disc moves from lower portion to upper portion. Due to

that movement they put the force on the disc. Then space between the brake disc

increases. On both side of the brake disc brake liner are attached. Due to increase in

gap these liner get attached with differential housing face and brake housing with a

great force. Due to friction between the brake liners and faces speed of tractor slow

down or stopped. Speed change into and to remove this heat from the inner space to

atmosphere vent breather situated into the assembly of brake. This way brake works

into the tractor.

For parking brakes one lever attached right hand side of the driver. This

lever entrapped the brake foot lever. This way parking brakes do his work. This lever is

attached on the gear box housing. One side of this lever teeth’s are manufactured.

These teeth are attached with the brake foot lever when we required. Releasing of this

brake is also very easy.

Lining wear

Lining wear is most important topic in the brakes. Because if brake liner

wears more rapidly than it is very bad for a tractor as well as for a manufacture. That is

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why lining wear is important during designing. Wear of the liner is more at near about

centre and continues decreases towards the outer ward face. That is why liner are

make is such a way they thicker at the centre and less thick at the outer surface.

Brake clearance

` At the time of operation of brakes, wear and rear of the lining takes place.

Hence, clearance provided between the lining and brake housing in the initial stage thus

necessitating adjustment. The adjustment made by the help of nut. The clearance

provided in the brake is mostly 1 to 2 mm.

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In between the differential and the driving wheels is the rear axle to transmit

power from the differential to the driving wheels. It is clear from the construction of the

differential, that the rear axle is not a single piece, but it is in two halves connected by

the differential, one part is known as half shaft. Inner end of the half shaft is connected

to the bull gear of the differential. And the other end to the driving wheel. Almost all rear

axles are live axle, that is, they revolve with the wheels. Dead axle simply remains

stationary; do not move with the wheels. Housing of rear axle is protecting from the

water, dust and injury, in addition their inner bearings and providing a container for the

lubricants.

Load on the rear axle

1 Total rear weight of the vehicle

2 Side thrust on the wheel

3 Driving torque

Types of Rear Axle

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1 Semi-floating

2 Full floating axle

3 Three quarter floating axle

Construction and working of the Rear Axle

In the construction, first of all housing of the rear axle is attached with the

differential housing with the help of studs. Half portion of stud is inside the differential

housing and other one in the rear axle housing. Between these parts seal or gasket is

adjusted to prevent the leakage of lubricant oil. Now axle put inside the housing. This

housing is hollow. One part of axle enters into the differential housing and other one out

from the rear axle housing. On the inner end of the axle bull gear is attached. Now with

the help of locking nut, it is locked.

First of all, power from the tail pinion is transfer to the crown wheel. Here whole

assembly of the cage revolves. Here power is transfer to the bull pinion shaft. Bull

pinion shaft is assembled with the bull gear. So power from the bull pinion shaft is

transfer to the bull gear. This gear is attached with rear axle. So from bull gear it is

transfer to the rear axle. This rear axle is attached with wheels. So this way power is

transferred from tail pinion to wheels through differential and rear axle.

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Rear Axle Assembly

Axle housing

On account of appearance, one piece of housing is called a banjo type. In this

design, the complete differential unit is carried in a separate casing which is bolted to

the axle casing. The two half shafts are put from the sides. In this design, if there is any

fault, the whole of the rear axle has to be removed as a unit and then disassembled.

Rear Axle Noises

Noise is a usual indication of trouble in the rear axle assembly. The causes of

noise should be carefully noted:

1 Noise occurs when the vehicle is pulling- the cause is probably insufficient clearance

between the gears.

a. Too much clearance between the gears

b. End play in the pinion assembly.

2 Noise occurs when vehicle is cornering- the cause may be faulty differential gears,

either damaged teeth or excessive wear

3 Noise occurs due to the shortage of oil or incorrect viscosity of oil.

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The noise sometimes appears coming from the rear axle, but actually may come

from the transmission, front wheel bearing or engine. The types also making a humming

sound on certain types of the road surface. Sometimes muffler noise may be considered

as coming from the rear axle. Therefore, it is important to check these conditions before

beginning to work on rear axle assembly.

Axle Breather

The heat generated by the gears causes to expand the air in the rear axle. It will

increase oil pressure also. To maintain oil pressure in the rear axle within limits so that

the oil is not pas the oil seal, an axle breather is provided on the axle casing.

Flow chart for Differential assembly

Visual inspection

Drain plug assembly

All stud fastening

Trumpt housing assembly

Bull gear assembly

PTO shaft, End cover, Cap assembly

Angle bracket assembly

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Brake pedal assembly

Cage assembly

Bull pinion shaft assembly

Seal carrier assembly

Tail pinion assembly

Brake housing assembly

PTO lever assembly

Suction strainer assembly

Rear axle assembly

Code punching and final inspection

Plan for gear assembly backlash checking

Serial no. Gear type Specification Instrument

used

Frequency Sample size

1 Front

transmission

gear

.2 to .35 mm Dial Gauge 100% 100%

2 Bevel gear .2 to .35 mm Dial Gauge 100% 100%

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(spider kit)

3 Bull pinion

shaft

.3 to .5 mm Dial Gauge 100% 100%

4 crown to

pinion

.25 to .35 mm Dial Gauge 100% 100%

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GEAR BOX ASSEMBLY

In Preet Tractors Pvt. Ltd the 2nd stage in the assembly shop is gearbox assembly. The

function of gearbox, its parts and working is explained as below: -

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FUNCTION OF GEARBOX

The main functions which are performed by the gearbox are: -

a) The torque or the tractive effort produced by the engine varies with speed only

within narrow limits. But the practical consideration for the running of tractor

under different conditions demands a large variation of torque available at the

wheels. The main purpose of the gearbox is to provide a means to vary the

leverage or torque ratio between the engine and the road wheels as required.

b) Gearbox also provides a neutral position so that the engine and the road wheels

are disconnected even with the clutch in the engaged position.

c) The third function of the gearbox is to reverse the rotation of the outgoing shaft

so as to drive the tractor in reverse direction.

TYPES OF GEARBOXES

Sliding mesh gearbox

Constant mesh gearbox

Synchromesh gearbox

Sliding Mesh Gearbox

1. Engine Shaft

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2. Lay Shaft

3. Main Shaft

4. First Gear

5. Second Gear

6. Third Gear

7. Fourth Gear

PARTS USED IN GEARBOX ASSEMBLY

Gearbox housing

Lay shaft

Four gears on lay shaft (Z-45, Z-36, Z-30 & Z-25)

Intermediate shaft

Three gears on intermediate shaft (Z-24, Z-31 & Z-34)

Input shaft

Four bearing 6209

Circlip

Spacers

Four shifter rods & forks (Hi-Low, 1st-Rev, 2nd & 3rd -4th )

Springs

Gaskets

C.A. Guide & C.A. Bush

Bottom cover plate

Drain plug

Greasing nipple

Idler gear

Idler gear pin

Washers

Hexagonal nut

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Z-F bracket

Steering assembly

Shifter lever housing

Levers

Planet gears

GEAR BOX HOUSING

LAY SHAFT ASSEMBLY

The lay shaft is hollow shaft with splines on outer surface. The one end of the lay shaft

is threaded (in case of single clutch) and tightened from front side of gearbox with

hexagonal nut. The whole assembly consists of gear Z-45(i.e. constant mesh gear with

input shaft gear), spacer 15mm, gear Z-36, gear Z-30, spacer 30.5mm, gear Z-25,

spacer 30.5mm, 3mm washer and bearing 6209 with Circlip. In case of dual clutch

tractor model the drive shaft is placed through the hollow lay shaft. The drive shaft

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consists of splines on one end and a gear (Z-45) on the other end. The gear constantly

meshed with the gear of intermediate shaft.

INPUT SHAFT ASSEMBLY

Input shaft consists of spiral gear on one end and splines on other end. Splined part is

attached to clutch and geared part (Z-19) is constantly meshed with gear of lay shaft i.e.

Z-45. Input shaft is put into the gearbox with the bearing 6209, which is locked by

Circlip.

OUTPUT SHAFT ASSEMBLY

Output shaft is solid shaft with splines on outer surface. The shaft is placed into gearbox

with both ends supported by bearing and locked by Circlip. The one end of shaft is

projected out side of gearbox from which drive is given to differential. The assembly of

shaft consists of gears Z-24, Z-31, Z-34. The sliding gear Z-34 is used for first and

reverse gear, sliding gear Z-31 is used for second gear and sliding gear Z-24 is used for

third and fourth gear. These gears are provided with grooves on one side to attach gear

shifter fork.

ASSEMBLY OF GEARBOX

First of all the gearbox housing is placed over the assembly stand with the help of

overhead crane. The idler gear is placed with the idler gear pin in the gearbox at its

respective place. Then lay shaft assembly is inserted into the respective hole and

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tightened from front side by hexagonal nut. After this, input shaft is placed in gearbox

housing. Its Z-19 is constantly meshed with Z-45 of lay shaft. Then the output shaft

assembly is placed into the gearbox housing where its one side is inserted into the input

shaft hole. For dual clutch models the intermediate shaft is hollow and placed over the

input shaft. Then Z-21 gear is meshed with Z-43 gear of connecting shaft, which is

placed through the hollow lay shaft. The internal gear assembly is tightened on the

outside of gear box with output shaft. The four shifter rods are placed in their respective

hole with spring loaded ball. The gear shifter forks are inserted into the groove of sliding

gears and then tightened to the gear shifter rods with the help of bolts. The fourth shifter

rod is meant for high and low-speed selection. This shifter rod is connected to the drive

shaft, which is placed into the internal gear. Then bottom cover plate is attached to the

bottom of gearbox housing with the help of gasket and four bolts. After this drain plug is

tightened. Now Z-F bracket is placed over the upper side of the gearbox. Z-F bracket

assembly is consists of steering assembly and shifter lever housing. Then whole

assembled gearbox is send to the main line assembly.

Gear Box Troubles

The most common trouble of the gear box and their causes are as follows:

1 Grinding noise in neutral- a grinding noise occurs when the engine is running and

tractor is in neutral. It is causes are:

a. Gear box is not properly aligned with the engine casing the shaft from the

flywheel to the gear box to bind

2 Noise in gear- when the tractor is being driven or rear wheels turning off the ground,

noise is heard in gear. Its causes are:

Dry rear bearing on the main shaft

Damaged drive gear

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The noise heard in the neutral will also be heard in the gear but will be more

pronounced.

Noise occurring in the rear end and in the clutch may be also seem to come from

the gear box

3 A hum or blow in neutral- when the engine is running, it occurs due to following

reasons

a. Lack of lubricants

b. Damaged shaft

c. Too much backlash between the gears

d. Gear chipped, burred, improperly matching and badly machined

e. Too much end play between the gears and counter shaft

f. Worn bearing

4 Hard shifting, sticking in gear- it occurs due to following reasons:

a. Distorted splines of the main shaft

b. Too strong shifter lock spring

c. Improper clutch adjustment

d. Battered gear tooth

5 Oil Leakage- oil leaks from the gear box due to following reasons:

a. Too high level in case

b. Damaged or improperly installed gasket or oil seal

c. Loose cover bolts

d. Cracked case or cover

e. Loose brain or filler plug

6 Slipping out of gear:

a. Too much clearance between the teeth in mesh

b. Insufficient mesh or gears

c. Worn gear of meshing teeth

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d. Weak or broken shifter lock spring

Assembly plan for Gear Box

Visual inspection

Drain plug assembly

Input shaft

Lay shaft

C.A guide, C.A bush, C.A shaft cover plate

Idealer gear

Main shaft

Shifter rod, fork, locking pins

Steering mounting bracket assembly

Steering assembly

Gear shifter housing

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Plant gear assembly

Work Instructions

1. First of all check the housing of gear box properly.

2. Fastening the stud with the help of stud fastener.

3. Fasten the drain plug when threads are cover with thread seal tape.

4. Fasten all nut, screw and bolt as according to given torque.

5. Use proper tool during assembly of oil seal and bearing.

6. Clean the shaft and gear with the help of diesel before fitting.

7. Check the backlash between the gears according to the given standards.

8. Check the pattern with the help of gauge.

9. Use lubricant up to proper level.

10.To lift the heavy parts always use Hoistus Crane.

11.Cover the washed parts properly.

12.Note all record in your register of sub assembly.

13.Attach the history card with the sub assembly.

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68

Hitch system

Introduction to Hitch system

We know very well that tractor is use for make the level of land, transportation,

cultivation of seeds. Pesticides etc. To do these types of work some implements

attached with the tractor at the behind portion. These implements are seed cum fertilizer

drill, leveller etc. Through which system these implements are attached is called hitch

system or linkage system.

Properties of a rood hitch and linkage system

1. First of all hitch system should be like that in which installation and reinstallation

of the implements are very easy.

2. It must help to implement to go in the deep point of the hard land.

3. It must help to the implement to stable at the same level in the land if level of

land are not stable.

4. Implement should move up and down very easily during transportation.

5. Side thrust should not affect the tools of field.

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Type’s of hitch system

Hitch system mainly divided into two types.

Single point hitch system:

It is also called integral hitch system. In this only draw bar is used

to attach various implements with the tractor. Draw bar is made by mild steel and

many holes drilled in this. In this holes with the help of pin tools are attached. That is

why it is called single point hitch system. In this system we are not able to pull the

tools but we are not able to lift the tools up and down. Also we are not able to control

the depth of tool in the field. This system is used only to attach trailing type harrow.

Three point linkage system:

This system mostly used into the tractors. We are able to use this system

as a single point linkage system. Main parts of this system follow:

a. Two lower links:

These links are assembled in tractor on the back side of the system. These are

attached on the right and left side. These links are made by the help of iron. This is a

piece of pressed iron. On both sides flexible ball socket are attached with them. With

the help of these tools are attached with tractor. Between these links right side link is

adjustable.

b. Top link or upper link:

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On this link also adjustable ball sockets attached. This link is adjustable

into length. End of draw bar is attached with this system. This draw bar also able to

attached with socket. This way it becomes single point hitch system. With this

system we are able to lift the implements of the tractor for example tiller, mounted

harrow. Seed cum fertilizer drill, leveller etc.

Lift and Hydraulic System

The system which help to move up and down to the cultivate tools and also

control the depth of the tool is called lift or hydraulic system.

During doing work on the field, we have to move up and down our cultivate tools

during cultivating and also we have to control the depth of tools, we have to do it

because structure, quantity and level of the soil is differ at every point. So if tools do his

work on the same level or on the same setting. Then sometimes tractor gets slipped

and sometimes engine has to do more work or we can say that 0verloading of engine.

So to over come on these problems hydraulic system is attached with tractor. Without

this system tractor are not able to complete his main motive.

Functions of Hydraulic system

1. With the help of two lower links tractor is able to move the cultivation tools up and

down.

2. This help to make a constant level of the tools as according to the structure or

level of the field.

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Main parts of Hydraulic System and working of these parts

This rear cover attached on the housing of differential and rear axle. Between

these housings lubricant oil is filled which help to do two works. One is that it helps

to lubricate parts of the differential and other it helps into the hydraulic system.

1. Filter

To remove the impurities from the lubrication this filter is used. Filter first

removes the impurities and then it delivers to the next part. Please check the

filter after some times otherwise it may be choke the hydraulic system.

2. Pump

This is a main part of this system. After removing of impurities oil reaches

into the pump. This pump is fitted front of the tractor. Drive is given to the pump

with the help of timing gears. It is the main function to increase the pressure of

the oil and deliver to next part. This is a gear type pump which converts

mechanical power to the hydraulic power. First oil reaches at the inlet port of the

pump and entrapped between the gears of the pump. This way its pressure

increases. This pump increases the oil pressure up to 135 kg/ square centimetre.

3. Ram and Power cylinder

In this part, one part is cylinder in which piston moves. This piston is

attached with rod. Second end of this rod is attached with two lower links. Oil

entre with pressure into the cylinder and put a pressure on the piston. This piston

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is attached with lower links which help to move up and down. By controlling the

oil pressure we can control the depth of the tools.

4. Distributor

In this system control valves and safety valves are attached. With the help

of this system we are able to control the oil pressure. If we want to give less or

more oil to the cylinder then this system works. If lift system feels load then it

works automatically and transfer oil to the tank. This system is made by the help

of three sliding valves and one by-pass valve and one safety valve.

73

74

Engine

In this tractor internal combustion diesel engine is used to produce the power.

Internal combustion engine mean that in these engine fuel is burned inside the engine

cylinder. Power is produced during the power stroke. This power helps to move the

tractor or for do work. In Preet tractor 2 cylinder, 3 cylinder and 4 cylinder engines are

used. By using number of cylinders and by using differ pistons differ horse power

produced. From this company we are able to purchase different kind of tractor which

has different horse power. Parts of engine are follows:

1. Cylinder block

2. Cylinder head

3. Crankcase

4. Piston

5. Piston rings

6. Connecting rod

7. Crankshaft

8. Flywheel

9. Valve and valve mechanism

10.Camshaft

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Cylinder Block

Cylinder block, cylinder head and crankcase- these three parts form the

foundation and main stationary body in the tractor. They serve as support and enclosure

for moving parts. The cylinder block and crankcase is manufactured together as a single

piece. This gives a rigid structure. Ribs are cast to give extra strength to the structure.

A cylinder block consists if mainly three parts:

1. The cylinder in which the piston slides up and down.

2. The ports or opening of the valves.

3. The passage for the flow of cooling water.

The round cylinder surface is given precision mirror finish by accurate grinding and

honing process. Cylinder head is made by cast iron and some quantity of nickel and

chromium is added in the cast iron. Cylinder walls are plated by chromium very hard

metal, to reduce the wall wear and to increase the service life.

Cylinder Head

The top of the cylinder is covered by a separate cast piece known as the cylinder

head. The cylinder head is bolted to the cylinder block. It contains combustion

chamber. It incorporates passages for the flow of cooling water. The cylinder usually

made of gray iron. It is separate from the cylinder block so that it mat be removed for

cleaning carbons and grinding valves.

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Care should be taken to the following points when detachable heads are made:

1. The bore of the cylinder or liner should not be destroyed by the pull of the holding

of down studs.

2. The circulation of the coolant in the cylinder head should be carried as nearly as

possible to the top end.

3. To ensure a sound gas tight joint, the holding down stud must be distributed as

uniformly as possible around the circumference of the cylinder.

Engine Assy.

Cleaning of Crank

Crank Shaft assembly In to Crank

Cam Shaft

Assembly of timing gears

Piston assembly

Oil pump

Suction strainer assembly

Front and rear cover

Oil pan assembly

Flywheel assembly

Cylinder head assembly

Fitment of all

Tappet assembly

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Rocker arm assembly

Belt pulley assembly

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Stores

The necessity of storing the material is to maintain a reserve of goods that will ensure

manufacturing according to the production plan based on sales requirements and the

lowest possible ultimate cost. Losses from improper inventory control include

purchase in excess then what needed, the cost of slowed up production resulting

from material not been available when wanted. Each time a machine is shut down for

lack of materials, or each time, sale is postponed or cancelled for lack of finished

goods a factory looses money.

Machine shop

In general, a machine is made up of many individual parts. For example a tractor is

made up of engine, gear box, electrical, suspension etc. The machine shop is

assigned the task of manufacturing individual parts or units of machine which are

assembled together to make the machine.

The machine shop includes following units:-

1. CNC – Computer Numeric Control.

2. Horizontal milling machine.

3. Vertical milling machine.

4. Radial machine (drilling).

5. SPM boring machine.

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Paint shop

The job assigned to paint shop is to paint the finalized machine. Here, the

concern is given on the outer appearance and to make the product look good and

attractive. After painting the machine, manufacturer logos are affixed and electrical

are also fitted. Then, final assembly is performed and machine is fitted with

electrical wirings and installations. The machine is ready for the pre delivery

inspection.

Pre delivery inspection

PDI means Pre delivery Inspection. When a vehicle comes from the

assembly shop after final assembly, they are first inspected after complete washing

and greasing.

The PDI is performed by two electricians, a mechanic and a helper for

each.

Following operations are performed here:-

1. Washing

2. Greasing

3. Engine oil check

4. Rear axle oil check

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5. gear box oil check

6. Test drive.

MAINTENANCE

In the modern industry, equipment and machinery are very important part of the total

productive effort. Lot of capital is invested in plant equipment and machinery. These

are deteriorated by their exposure to environmental and working conditions. If these

damages are not checked at proper time, these may make the equipment non-

usable. Thus it is very important to maintain, repair and recondition these to increase

their life and make them available for maximum number of operating hours. The

various objective of the maintenance department are:

To achieve minimum breakdown.

To keep the plant in good working condition at the lowest possible cost.

To prevent loss in production time.

To maintain the various plant services.

To provide plant protection including fire protection.

To establish and maintain a suitable store of maintenance materials.

Insurance administration.

Generation and distribution of power and other facilities.

Overhauling of plant equipment and machinery.

To carry out corrective repairs to alleviate unsatisfactory conditions found

during preventive maintenance inspection.

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VARIOUS TYPES OF MAINTENANCE:

1. BREAK DOWN MAINTENANCE :

This maintenance is to deal with the problems in which the machine may be

running but the final product which we are supposed to get is not

available .Means the output is not of desired accuracy e.g. dimensions of the

product are not up to the mark or shape may be distorted .

2. PREVENTIVE MAINTENANCE :

In this the prevention of the machine is considered , time to time checking of the

machine is done so that they work properly & production is good .on Sundays

machines are checked , oil filters , electric wires, cables are checked .

3. INSTALLATION & COMISSIONING :

It includes installation of machines also includes loading & unloading of the

machines to place them at proper place. Inspection is done by some specialized

engineers.

4. SERVICES :

It includes various things which maintenance department has to look after, for the

proper running of the industry. Without this many problems may occur. Service

block consist of:

Generator (2 in no)

Compressor (3 in no)

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Compressed air drier

Cooling tower

Softening plant ETP( Effluent treatment plant)

Air receiver

SERVICES

TELEPHONE WATER OIL ELECTRICITY COMPRESSED AIR

Machine Fuel Engine Oil Oil Oil

DG Set & Production Engine Testing

Hydraulic oil Lubricating oil Cutting oil Washing M/C Diesel, (Engine oil)

INDUSTRIAL ENGINEERING

To repair all Telephone lines inside the plant

From NAC (notified areas committee. Takes care of water supply

Supply of 11KV.transformers 2 each of 1500KVAcapacity

To provide compressed air.CompressorGenerates air at7 kg/cm sq. 14 kg /cm sq

18 kg/cm sq

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Industrial Engineering is the most important department in terms of production,

planning, designing and optimization of methods governing the factory operations. It

deals in utilization of resources i.e. manpower, machines, money etc. Hence it can

be considered as the backbone of production industries. For a new industry I.E

department plays an important role.

Its main functions involve the planning of layouts of all the shops to get the

maximum benefits of the available space, setting the time standards to perform

particular job by micro motion study, implementing the company standards. All type

of data collection and data analysis; setting the targets and try to achieve them etc.

the other function of this department may involve selection of cutting tools machine

tools, designing of jigs, fixtures and inspection of gauges etc.

In I.E there are following four sections:

Machine Shop Processing:

This section controls processing of all components in machine shop and

make continues production and make C.N.C. machines program for new

components and improving exiting programmes. The new machines are setup

by this section and development of new comp. also done.

Assembly and Projects:

This section controls the assembly shop and testing lab of plant. And ensure

assembly line goes smoothly and fulfil its targets. It also implements new

projects in the plant for increasing production and convenience of workers or

operators. It also done time study and work study.

Tool Control Cell:

It controls tool crib of plant and assures proper supply of tools to various

machines and also store proper amount of tools for regular production of

components. It also reworks or re sharps the damaged tools.

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Tool Design Cell

This section designs new tools, jigs, fixtures etc. according to requirements of

various departments. It also improves exiting fixtures to achieve greater

accuracy.

The Functions of I.E. are following:

1. Plant layout:

The best optimum utilization of space can be achieved by optimum layouts. An

improper layout may result in wastage of manpower and hence production so the

most important and first task of I.E in setting up a new industry and expanding

the old is planning and making the layout according to the requirements of the

process .

2. Installation of new machines :

The function of I.E is to install the new machines acc. to proposed layout.

While installing the new machines and other systems, the I.E has to take

care of some precautions like ease of the worker to do his work easily, safety

measures etc.

3. Setting the standard timing of workers:

The next function of I.E is to set the worker to perform certain operations. This

is calculated by the micro motion study in which stop watch is used which

record all the minute time period spent by the worker in different steps of the

work and after that all the periods are added up thus giving the total time to

do a complete operation. With the help of that determined time by the

camera, the standard time of operation has been found out according to the

formula:-

Standard time =Normal time + Allowance

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When the normal time is determined by the camera and allowances is that

time which the workers spends for his personal needs etc.

4. Appropriate selection of the m/c and cutting tool

5. Designing the jigs, fixtures and inspection gauges

6. Planning the manufacturing of new components

7. Receiving components and drawings from R&D

8. Prepare and release of process sheet.

9. Miscellaneous and advisory functions.

86

87

PROJECT NO.1

Aim: - Making hardness chart of various parts of tractor which are generally undergoing

to check in quality control for hardness purposes.

Requirement of Hardness Chart:-

If any component which is come under line rejection in quality control for mainly

hardness then there is no need to open the control plan of that components,

simply see the hardness of that component from hardness chart and check it

again with suitable instrument.

It is easy to locate the component control plan from the file by note the

component part no. from the hardness chart.

It is beneficial for trainee students and for trainee engineers that they not know

hardness of various components of tractors.

Control Plans used for making Hardness chart:

Rear Cover

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Front Axle

Differential

Gear and Shafts

Gear Box

Hardware

HARDNESS CHART INCLUDES FOLLOWING COMPONENTS

REAR COVERS.NO. PART NO. DESCRIPTION HARDNESS

1 401004 POSITION ACTUATOR ASSY. 58-63HRC2 401007 POSITION LINK ASSY. 30-35HRC3 401010 DRAFT LINK ASSY. 35-40HRC4 401011 SENSOR LEVER HINGE PIN 25-30HRC5 401013 SENSOR (L-42) 40-45HRC6 401017 SENSOR ROD 30-36HRC7 401020 PIN ROCKER LINK 25-30HRC8 402008 CONNECTING ROD 40-45HRC9 402010 LIFT ARM ASSY. 58-62HRC10 405009 POSITION CRANK ASSY. 20-24HRC11 405016 RETAINING PIN (BIG) 20-25HRC12 403007 RESPONE VALVE 25-30HRC13 402018 LINEAR 50-60HRC14 104005 LINK PIN 25-30HRC15 403006 BALL SHEET 50-60HRC16 104006 LINCH PIN 25-30HRC17 403002 PLUG 20-25HRC18 104004 PIN 25-30HRC19 401023 PIN 25-30HRC20 4010106 SWIVEL PIN 25-30HRC

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21 402021 INSERT 40-45HRC22 402016 ROCK SHAFT 50-55HRC23 405023 DRAFT LEVER ASSY. 35-40HRC24 405013 POSITION LEVER ASSY. 35-40HRC25 405007 DRFT CRANK ASSY. 20-40HRC

DIFFERENTIALS.NO. PART NO. DESCRIPTION HARDNESS

1P010300

5 P.T.O. COVER PLATE ( L ) 180-230BHN

2P040600

1 P.T.O. COVER PLATE ( R ) 180-230BHN3 401019 ROCKER LINK ASSY. 40-45HRC4 407023 DRAW BAR 25-30HRC

5M080500

7 WITHDRAWL NUT (PINION42X1.5) 25-30HRC6 301005 PLATE ASSY. ( L ) 25-28HRC7 301006 PLATE ASSY. ( R ) 25-28HRC8 407025 LOWER LINK BRACKET ( L ) 25-30HRC9 407026 LOWER LINK BRACKET ( R ) 25-30HRC

FRONT AXLES.NO. PART NO. DECRIPTION HARDNESS

1 502013 STEERING ARM ( L ) 210-240BHN2 502009 STEERING ARM ( R ) 210-240BHN3 502007 HUB CAP 130-180BHN4 501021 DOWEL LEEVE 20-25BHN5 502008 O-RING HOLDER 20-25BHN6 501003 PIN ( TOE HOOK ) 35-42BHN7 502002 WEAR RING ( STUB AXLE ) 45-50BHN8 502015 KING PIN 45-50HRC9 501010 PIVOT PIN 25-35HRC

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HARDWARES.NO. PART NO. DESCRIPTION HARDNESS

1 P0609002 RUBBER PAD ( FLY WHEEL ) SH 65 ±52 301002 WHEEL BOLT ( REAR AXLE ) 20 - 25HRC3 301003 WHEEL NUT ( REAR AXLE ) 20 - 25HRC

4M080600

1 STUD ( M16X1.5 ) 20 - 25HRC5 P0301007 RUBBER PAD ( FENDER ) SH 80 ±56 104007 DRAIN PLUG ( M24X1.5 ) 20 - 25HRC7 1003009 HOSE PIPE SH 60 - 658 402025 O RING SH 65 ±5

9M081100

0 COPPER WASHER 40 -45HRC10 406034 SPECIAL STUD 20 - 25HRC11 406031 SEALING WASHER SH 65 ±512 106020 O RING (B.P.S.) SH 65 ±513 401022 O RING (SENSOR) SH 65 ±515 406025 SEALING RING SH 65 ±516 402012 SEAL RING (ROCK SHAFT) SH 65 ±5

GEAR BOXS.NO. PART NO. DESCRIPTION HARDNESS

1 P0204009 INNER BUSH 180-230BHN2 P0210004 SHIFTER LEVER 50-60HRC3 P0210005 SHIFTER LEVER (HI - LOW) 55-60HRC4 P0203017 BOTTOM COVER PLATE 180-230BHN5 207024 IDLER CLUSTER PIN 58-63HRC6 203010 LOCKING PIN 38-43 HRC

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30-40 HRC7 207015 WITHDRAWL NUT (C.S.) 25-30HRC

GEAR AND SHAFTSS.

NO. PART NO. DESCRIPTION HARDNESS

1 P0105001 BULL GEAR58-63HRC

2 P0105005 BULL PINION SHAFT ( L ) 58-63HRC3 P0105016 BULL PINION SHAFT ( R ) 58-63HRC4 P0207020 C. M. GEAR Z-43 DUAL 58-63HRC5 P0102002 CONNECTING SHAFT SMALL 58-63HRC6 P0207023 CONNECTING SHAFT BIG 58-63HRC7 P0207005 CONSTNT MESH GEAR Z-45 58-62HRC8 P0105009 CROWN WHEEL Z-42 58-62HRC9 P0207019 DRIVE SHAFT Z-21 58-62HRC

10 P0207002 FIXED GEAR Z-25 58-62HRC11 P0207003 FIXED GEAR Z-30 58-62HRC12 P0207004 FIXED GEAR Z-36 58-62HRC13 P0207015 IDLER CLUSTER GEAR Z-15, Z-21 58-63HRC14 P0205001 INPUT SHAFT Z-19 58-60HRC15 P0206001 INTERMEDIATE SHAFT 58-63HRC16 P0206008 INTERNAL GEAR (4+1) 58-63HRC17 P0206009 OUTPUT SHAFT 58-63HRC18 208009 PLANET GEAR 60-62HRC

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19 P0102006 PTO SHAFT (21 SPLINES) 52-60HRC20 206020 SLEEVE HI/LOW 50-55HRC

21 P0206002 SLIDING GEAR 34/12 58-63HRC22 P0206003 SLIDING GEAR Z-31 58-63HRC23 P0206004 SLIDING GEAR Z-24 58-63HRC24 101001 TAIL PINION 58-63HRC25 105006 CROSS 58-63HRC26 105007 BEVEL GEAR ( L ) 58-63HRC27 105008 BEVEL GEAR ( R ) 58-63HRC28 105011 BEVEL PINION 58-63HRC

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Project No. 2

AIM: - To implement power steering on the tractor to make the steering simpler and

easier.

REQUIREMENT OF THIS PROJECT

Larger amount of torque is required to be applied by the driver for steering of

medium and heavy vehicles

Heavy vehicles such as Off-road trucks, fork lifts, earth moving machines, and

tractors demands high steering forces.

Mechanical linkage between the steering wheel and the steered wheels would be

more difficult and expensive in compact design vehicles.

APPLICATIONS

• Agriculture

• Construction

• Forklift trucks

• Lawn and garden

• Mini tractors

• Municipal vehicles

94

COMPONENTS OF POWER STEERING

1. STEERING WHEEL: - its diameter is 350mm [14 inch.], 3 spoke steering wheel with

knob standard and optional horn button.

2. STEERING COLUMN

Steering columns connect the steering wheel to the steering unit.

The steering column must be supported when its length exceeds 150 mm.

The mounting of the steering column must be properly aligned so that the

steering unit can return to neutral position automatically after a steering action

has been completed.

The construction of the steering column must ensure that no axial or radial forces

are transferred to the steering unit input shaft.

95

3. STEERING UNIT

It has four ports, one is connected to tank or reservoir, one is connected to pump,

and remaining two is connected to steering cylinder.

It controls the flow of oil in different ports.

It is rigidly fixed with steering column.

4. TANK

It provides the oil to the pump.

It has two ports one is connected to steering column and other is connected to

pump.

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The oil used must be filtered for better working of the system.

A magnetic insert is recommended when using filters larger than 25 micron.

5. STEERING CYLINDERS:-

The steering cylinder used in this power steering is double acting balanced

cylinder.

Balanced cylinders are compact and eliminate differences between steering

wheel turns and steering forces because of equal volumes.

6. PUMP:-

The hydraulic power for the steering is provided by a rotary-vane pump (see

diagram below).

97

This pump is driven by the tractor's engine via a belt and pulley.

Correct pump sizing is important in avoiding unnecessary energy consumption,

or slow response to steering demand.

It supplies the required pressure to oil.

98

LAYOUT OF HYDROSTATIC

POWER STEERING

99

HOW TO SIZE THE CORRECT STEERING SYSTEM

STEP 1. TOTAL STEERING TORQUE:-

Total steering torque, T = C.f (√B2/8 + E2 ) kgmm

Where C = Load on the steered axle (in kgmm)

E = King pin offset (in mm)

B = Tyre breadth (in mm)

LOAD ON THE STEERED AXLE,

C = 1030 (LOAD ON FRONT STEERING)

+2000 (Load of the loader)

C = 3030 kg

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E/B = 60/190 = .316

(WHERE B=190,E=60)

F = 0.4 (from above graph )

Where f = coefficient of friction(dimensionless).Based on 0.7

As maximum.

T = 3030X0.4 √(190)2/8+(60)2 kgmm = 3030X0.4X90.07 kgmm

T = 109164.13 kgmm

STEP 2. FORCE REQUIRED FOR AXLE :-

F= Mr/Rmin.

Where F = Required piston rod force (in kg),

Rmin. = Minimum effective radius arm (mm)

F= 109164.13/100 kg

F = 1091.64 kg

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A = F/P cm2

Where A = Pushing cylinder area (mm2),

P = Steering max. pressure in bar

A = 1091.64/90 = 12.13 cm2

A = 1213 mm2

STEP 3. SELECTING STEERING UNIT DISPLACEMENT :-

Before proceeding further, a decision must be made as to the number of steering wheel

revolutions desired for the application to steer the axle from full one side to the.

Depending on vehicle usage, this will vary, normally 2 1/2 to 5 1/2 with 4 being a good

typical value.

Area of cylinder, A = Π/4[(D)2-(d)2] = Π/4[(60)2-(36)2]

A= 1808 mm2

As 1808 > 1213

Therefore it is acceptable.

Stroke length, S = 175 mm

Volume, V = 1808X175mm3 = 316400mm3

V = 316.4 cm3 ,The volume of oil required to move cylinder rod(s) through the entire

stroke.

Total wheel turns, N = 3

Therefore, steering unit displacement, Cu = V/N = 316/3 cm3/rev.

Cu = 105 cm3/rev.

As the calculations are complete, we select the closest standard steering unit

displacement (i.e. 100 cc unit) from catalog information.

STEP 4. CALCULATING REQUIRED PUMP FLOW :-

We select Dowty pump IP 30 28,which has discharge of 12.7 liter at 1500 rpm.

At 1000 rpm its discharge will be = 12.7X1000/1500

= 8.5 liter/min.

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Hence at 1000 engine rpm, we shall be able to get 8.5 liter./min. which means we can

steer wheel = 8.5X1000/100 = 85 rpm which is fairly ok and at 2000 rpm of engine

we shall be able to steer wheel by 170 rpm.

STEERING TROUBLE SHOOTING

1. EXCESSIVE BACKLASH IN STEERING :- The most probable cause of this

trouble is the slackness in the steering linkage due to wear of bell joints and

steering.

2. WANDER :- When the vehicle is being driven straight, it turns slightly to one side

and when the driver turns the steering to bring it back to the straight ahead, it

turns slightly to the other side, thus the driver has to adjust steering constantly to

keep the vehicle direction straight, the effect is called wander.

3. PULLING TO ONE SIDE :- Sometimes the vehicle constantly pulls towards one

side.

4. WHEEL WOBBLE(LOW SPEED SHIMMY) :- The oscillation of the front wheels

at low speeds is called wobble.

5. HIGH SPEED SHIMMY :- The oscillation of the front wheels at high speed is

called high speed shimmy.

6. WHEEL TRAMP:- Sometimes the front wheels of vehicle at high speeds

vibrate so violently that an almost uncontrollable motion of the vehicle is

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caused that is called wheel tramp.

7. EXCESSIVE TYRE WEAR:- This is normally due to incorrect tyre

pressure, excessive toe-in or toe-out.

8. HARD STEERING :- When the effort required for steering is more than the

normal steering force.

9. POOR RETURNABILITY:- Poor return of the steering wheel to centre may be

due incorrect tyre pressure, tight or frozen steering shaft bearing, and incorrect

front wheel alignment.

BENEFITS

Minimizes steering linkage-reduces cost, provides flexibility in design.

Provides complete isolation of load forces from control station-provides operator

comfort.

Provides continuous, unlimited control action with very low input torque.

Date post:	17-Nov-2014
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