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Technical Orientation

Alex Ek & Michael Haber

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Overview

Three Major Product Lines

Couplings

U-Joints

Machined Springs

Over 26,000 different configurations

Defined by how they are being used

Let’s talk about couplings

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Technical Orientation Goals

Introduce flexible shaft couplings

Discuss the Helical coupling and how it works

Cover the possible variations of the coupling

Flexure

Material

Attachments

Virtues of the Flexure

Unvirtues of the Flexure

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Why Couplings?Definition: a connection or joint between two things.

http://en.wikipedia.org/wiki/Coupling_(disambiguation)

Shaft coupling: A connection between two shafts.

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

Flexible shaft coupling: A connection between two unaligned shafts.

Must accommodate misalignment

Must transmit torque and position

Must survive its environment

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Why use a Flexible Coupling?Compensate for ____________ ?

Tolerances of machined parts

Dimensions effected by heat

Misalignments between shafts

All of the above

Sources of Misalignments ?

Misalignment Types

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What are Tolerances?Nothing is “perfect”

Tolerance is how much a dimension is allowed to deviate from “perfect”

Example:

Resonance Oscillator

Parts:

Motor

Motor Mount

Base

Bearing Block

Bearings

Shaft

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What are Tolerances?

Motor

Motor Mount

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What are Tolerances?

Base

Bearing Block

Bearing

Shaft

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What are Tolerances?Vertical tolerance stack up worksheet (inches):

Motor 0.002Motor Mount +- 0.005 Base 0Bearing Block +- 0.005Bearings 0.0005Shaft 0.0005

_________________________________________Maximum total 0.013

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Misalignments

Our rotating life tester

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Misalignments

Angular Misalignment

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Misalignments

Angular Misalignment – large angle

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Misalignments

Angular Misalignment – large angle

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Misalignments

Parallel Offset

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Misalignments

Parallel Offset - large

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Misalignments

Axial Motion

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Misalignments

Axial Motion - extension

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Misalignments

Axial Motion - compression

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What is Torque ?“A force applied across a distance from a center of rotation

creates twist or torque”

Torque ( lbin )= perpendicular force * distance

Units: lbin or Nm

“” = (63000*HP)/RPM (lbin)

What is the metric equivalent of Horsepower?

Watts or KW.

0.746 KW = 1 Hp.

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Foot-pounds and pound-feet—what’s the difference?

http://www.macsmotorcitygarage.com/2013/10/24/foot-pounds-and-pound-feet-whats-the-difference/

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Helical’s Torque Rating SystemMomentary Dynamic Torque

Listed in catalog

40% of Material yield strength

Non-Reversing Torque

Divide Momentary by 2

Reversing Torque

Divide Momentary by 4

Why torque and not horsepower?

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Torsional FlexibilityPredictable twisting from applied Torque

Similar words; “Torsional _________”

Stiffness

Rigidity

Wind-up

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Torsional Flexibility

Relaxed Wound Up

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Backlash

Unpredictable position due to clearances between input and output

Everything has Flexibility, Stiffness, Wind-up…

Not everything has backlash

Backlash

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Unique Helical Coupling Features

One-piece Construction

No Backlash

No Lubrication

Choice of Materials

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Flexure VersatilityColored Samples

Width of coils (Red)

OD & ID changes (Green)

Number of coils (Blue)

Number of starts (Gold)

Number of Flexures

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Width of Coils

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ID Changes (OD also)

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Number of Coils

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Multiple Start

Single Double

Triple

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Multiple Flexure

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Technical OrientationStandard Materials

Aluminum Alloy 7075-T6

Stainless Steel 17- 4 PH

Stainless Steel 303 (not our favorite)

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What is a Relief?

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Attachments

Standard Attachments

Integral Clamp Set Screw

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HP-85 print head positioner drive.

Circa 1980

What Needs a coupling?

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Food dispensing and Secret Medical Stuff

What Needs a coupling?

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What Needs a coupling?

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Aircraft engines and controls

What Needs a coupling?

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Technical Orientation

Flexure unvirtues

Yes, they can break!

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And next is . . .

Specifying and Promoting Couplings

With Derek & Tom