+ All Categories
Home > Documents > Cam Dynamic Synthesis

Cam Dynamic Synthesis

Date post: 02-Jun-2018
Category:
Upload: petrescu-florian
View: 218 times
Download: 0 times
Share this document with a friend

of 23

Transcript
  • 8/10/2019 Cam Dynamic Synthesis

    1/23

    Al-Khwarizmi

    Engineering

    Journal

    Al-Khwarizmi Engineering Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    Cam Dynamic Synthesis

    Florian Ion T. Petrescu* Relly Victoria V. Petrescu***Department of Theory of Mechanisms and Robots/ Polytechnic University of Bucharest / Romania / Europe

    ** Department of Transport, Traffic & Logistic Department / Polytechnic University of Bucharest/ Romania / Europe

    *E-mail: [email protected]

    **E-mail: [email protected]

    (Received 10 October 2013; accepted 4 February 2014)

    Abstract

    The paper presents an original method to make the geometric synthesis of the rotary cam and translated tappet with

    roll. Classical method uses to the geometric synthesis and the reduced tappet velocity, and in this mode the geometric

    classic method become a geometric and kinematic synthesis method. The new geometric synthesis method uses just the

    geometric parameters (without velocities), but one utilizes and a condition to realize at the tapped the velocities

    predicted by the tapped movement laws imposed by the cam profile. Then, it makes the dynamic analyze for the

    imposed cam profile, and one modify the cam profile geometric parameters to determine a good dynamic response

    (functionality). In this mode it realizes the dynamic synthesis of the cam, and we obtain a normal functionality.

    Keywords: Geometric synthesis, Dynamic synthesis, Rotary cam, Translated tappet with roll.

    1. Introduction

    In conditions which started to magnetic

    motors, oil fuel is decreasing, energy which wasobtained by burning oil is replaced with nuclear

    energy, hydropower, solar energy, wind, and othertypes of unconventional energy, in the conditionsin which electric motors have been instead ofinternal combustion in public transport, but morerecently they have entered in the cars world

    (Honda has produced a vehicle that uses acompact electric motor and electricity consumedby the battery is restored by a system that uses anelectric generator with hydrogen combustion incells, so we have a car that burns hydrogen, but

    has an electric motor), which is the role andprospects which have internal combustion enginestype Otto or Diesel?

    Internal combustion engines in four-stroke

    (Otto, Diesel) are robust, dynamic, compact,powerful, reliable, economic, autonomous,independent and will be increasingly clean.

    Let's look at just remember that any electric

    motor that destroy ozone in the atmosphereneeded our planet by sparks emitted by collectingbrushes. Immediate consequence is that if we onlyuse electric motors in all sectors, well haveproblems with higher ozone shield that protects

    our planet and without which no life could existon Earth.

    Magnetic motors (combined with theelectromagnetic) are just in the beginning, butthey offer us a good perspective, especially in the

    aeronautics industry.Probably at the beginning they will not be used

    to act as a direct transmission, but will generateelectricity that will fill the battery that willactually feed the engine (probably an electric

    motor).The Otto engines or those with internal

    combustion in general, will have to adapt tohydrogen fuel.

    It is composed of the basic (hydrogen) canextract industrially, practically from any item (or

  • 8/10/2019 Cam Dynamic Synthesis

    2/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    2

    combination) through nuclear, chemical, photonic

    by radiation, by burning, etc... (Most easilyhydrogen can be extracted from water by breaking

    up into constituent elements, hydrogen andoxygen; by burning hydrogen one obtains wateragain that restores a circuit in nature, with no

    losses and no pollution).Hydrogen must be stored in reservoirs cell (a

    honeycomb) for there is no danger of explosion;the best would be if we could breaking up waterdirectly on the vehicle, in which case the reservoirwould feed water (and there were announcedsome successful).

    As a backup, there are trees that can donate afuel oil, which could be planted on the extendedzone, or directly in the consumer court. Withmany years ago, Professor Melvin Calvin,(Berkeley University), discovered that Euphoratree, a rare species, contained in its trunk a liquidthat has the same characteristics as raw oil. Thesame professor discovered on the territory ofBrazil, a tree which contains in its trunk a fuelwith properties similar to diesel.

    During a journey in Brazil, the natives drivenhim (Professor Calvin) to a tree called by them

    "Copa-Iba".At the time of boring the tree trunk, from it to

    begin flow a gold liquid, which was used asindigenous raw material base for the preparationof perfumes or, in concentrated form, as a balm.

    Nobody see that it is a pure fuel that can be useddirectly by diesel engines.

    Calvin said that after he poured the liquidextracted from the tree trunk directly into the tankof his car (equipped with a diesel), engine

    functioned irreproachable.In Brazil the tree is fairly widespread. It could

    be adapted in other areas of the world, planted inthe forests, and the courts of people.

    From a jagged tree is filled about half of thetank; one covers the slash and it is not open until

    after six months; it means that having 12 trees in acourtyard, a man can fill monthly a tank with thenew natural diesel fuel.

    In some countries (USA, Brazil, Germany)producing alcohol or vegetable oils, for their useas fuel.

    In the future, aircraft will use ion engines,magnetic, laser or various micro particlesaccelerated. Now, and the life of the jet enginebegin to end.

    Even in these conditions internal combustionengines will be maintained in land vehicles (at

    least), for power, reliability and especially theirdynamics. Thermal engine efficiency is still lowand, about one third of the engine power is lost

    just by the distribution mechanism. Mechanical

    efficiency of cam mechanisms was about 4-8%. Inthe past 20 years, managed to increase to about

    14-18%, and now is the time to pick it up again atup to 60%. This is the main objective of thispaper.

    2. Presenting a Dynamic Model, with one

    Grade of Freedom, with Variable

    Internal Amortization

    2.1.Determining the Amortization

    Coefficient of the Mechanism

    Starting with the kinematical schema of theclassical valve gear mechanism (see the Figure 1),

    one creates the translating dynamic model, with asingle degree of freedom (with a single mass),with variable internal amortization (see the Figure2), having the motion equation (1) [3, 13].

    The formula (1) is just a Newton equation,where the sum of forces on a single element is 0.

    0)( FxcxkxyKxM (1)

    5 1

    2

    3

    4

    A

    B

    C

    D

    C0

    O

    Fig. 1. The Kinematical schema of the classical

    valve gear mechanism.

    The Newton equation (1) can be written in theform (2).

    )()( 0 xkFxyKxcxM (2)

  • 8/10/2019 Cam Dynamic Synthesis

    3/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    3

    M M

    k

    kx F

    F(t) c .

    cx

    xx(t)

    K(y-x)K

    y(t)

    cam

    Fig. 2. Dynamic Model with a Single Liberty, with

    variable internal amortization.

    The differential equation, Lagrange, can bewritten in the form (3).

    rm FFxdt

    dMxM 2

    1 (3)

    Comparing the two equations, (2 and 3), oneidentifies the coefficients and one obtains theresistant force (4), the motor force (5) and thecoefficient of internal amortization (6). One cansee that the internal amortization coefficient, c, isa variable.

    )( 000 xxkxkxkxkFFr (4)

    )()( xsKxyKFm (5)

    dt

    dMc 2

    1 (6)

    One places the variable coefficient, c, (see therelation 6), in the Newton equation (form 1 or 2)

    and obtains the equation (7).

    0)(

    2

    1FyKxkKx

    dt

    dMxM (7)

    The reduced mass can be written in the form(8), (the reduced mass of the system, reduced atthe valve).

    244

    211

    22325

    )()(

    )()(

    xJ

    xJ

    x

    ymmmM

    (8)

    With the following notations:

    m2 =the mass of the tappet (of the valve lifter); m3=the mass of the valve push rod; m5 =the valvemass; J1 =the inertia mechanical moment of the

    cam; J4 =the inertia mechanical moment of the

    valve rocker; 2y =the tappet velocity, or the

    second movement-low, imposed by the camsprofile; x =the real (dynamic) valve velocity.

    If one notes with i=i25, the ratio of transmission

    tappet-valve, given from the valve rocker, thetheoretically velocity of the valve, y , (the tappet

    velocity reduced at the valve), takes the form (9),

    where the ratio of transmission, i, is given fromthe formula (10).

    i

    yyy 25

    (9)

    DC

    CCi0

    0 (10)

    One can write the following relations (11-16),where y is the reduced velocity forced at thetappet by the cams profile. With the relations (10,13, 14, 16) the reduced mass (8), can be written inthe forms (1719).

    '1 xx (11)

    ''21 xx (12)

    '1'

    212 yiyy (13)

    '

    1

    '1

    11

    xxx

    (14)

    DC

    y

    DC

    CC

    CC

    y

    CC

    iy

    CC

    y

    CC

    y

    0

    1

    0

    0

    0

    1

    0

    1

    0

    '

    21

    0

    2

    4

    ''

    '.

    (15)

    '

    '1

    '

    '

    010

    14

    x

    y

    DCxDC

    y

    x

    ..(16)

    2

    0

    4

    2

    1

    2

    325

    )'

    '1()

    '

    1(

    )'

    '()(

    x

    y

    DCJ

    xJ

    x

    yimmmM

    (17)

    2

    1

    2

    2

    0

    4

    32

    2

    5

    )'

    1()

    '

    '(])(

    )([

    xJ

    x

    y

    DC

    J

    mmimM

    (18)

    2

    1

    2

    5 )'

    1

    ()'

    '

    (* xJx

    y

    mmM ..(19)

  • 8/10/2019 Cam Dynamic Synthesis

    4/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    4

    It derives dM/d and obtains the relations (2022).

    )'

    ''

    '

    ''()'

    '(2)'

    '''''('

    '2

    '

    )''''''(

    '

    '2])

    '

    '[(

    2

    2

    2

    2

    x

    x

    y

    y

    x

    y

    x

    yxyx

    y

    x

    yxxy

    x

    y

    d

    x

    yd

    ...(20)

    32

    2

    '

    ''2

    '

    ''

    '

    2])'

    1[(

    x

    x

    x

    x

    xd

    xd

    (21)

    31

    2

    '

    ''2)'

    ''

    '

    ''()'

    '(*2

    x

    xJ

    x

    x

    y

    y

    x

    ym

    d

    dM

    ...(22)

    The relation (6) can be written in form (23) andwith relation (22), its taking the forms (2425).

    d

    dMc 2

    (23)

    }'

    '')'

    ''

    '

    ''()

    '

    '(

    ])(

    )({[

    31

    2

    2

    0

    432

    2

    x

    xJ

    x

    x

    y

    y

    x

    y

    DC

    Jmmic

    (24)

    ]''')

    '''

    '''()

    ''(*[

    312

    xxJ

    xx

    yy

    xymc (25)

    With the notation (26):

    2

    0

    4

    32

    2

    )()(*

    DC

    Jmmim (26)

    2.2.Determining the Movement Equations

    With the relations (19, 12, 25, 11) the equation

    (2) take the forms (27, 28, 29, 30 and 31) [13]:

    0

    2 )(''' FyKxkKxcxM (27)

    03

    ''

    1

    2'

    '

    ''

    '

    ''2*'22''2

    '1

    ''2*2

    5

    ''2

    )('

    )()'

    '()

    1(

    )'

    '(

    FyKxkKx

    x

    Jx

    x

    x

    y

    y

    x

    ymxx

    xJ

    xx

    ymmx

    (28)

    0

    *2

    2*22*2

    5

    2

    )('

    '''

    '')'

    '()

    '

    '(''''

    FyKxkKx

    yym

    xx

    ym

    x

    yxmxm

    (29)

    0

    ''*2''

    5

    2

    '

    ')( FKy

    x

    yymxkKxm

    (30)

    0

    *

    5

    2)()

    '

    '''''( FyKxkKx

    yymxm

    (31)

    The exact equation (31) can be approximated

    at the form (32) with xy.

    0*

    52 )()''''( FyKxkKymxm

    (32)

    With the following notations: y=s, y=s,y=s, y=s, the equation (32) takes theapproximate form (33) and the complete equation

    (31) takes the exact form (34).

    0

    *

    5

    2)()''''( FsKxkKsmxm

    (33)

    052 )()

    ''''*''( FsKxkK

    xssmxm

    (34)

    Solving the Differential Equation by Direct

    Integration and Obtaining the Mother

    Equation

    One integrates the equation (31) directly. Oneprepares the equation (31) for the integration.First, one writes (31) in form (35) [13].

    I

    III

    TII

    Sx

    yymxm

    xkyKxkK

    2*

    2*

    0)(

    (35)

    The equation (35), can be amplified by x andone obtains the relation (36).

    III

    T

    III

    S

    III

    yymxxm

    xxkxyKxxkK

    2*2*

    0)(

    (36)

  • 8/10/2019 Cam Dynamic Synthesis

    5/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    5

    Now, one replaces the term K.y.x

    with IykK

    KyK

    , (taken in calculation the

    statically assumption, Fm=Fr) and one obtains the

    form (37).

    III

    T

    III

    S

    III

    yymxxm

    xxkyykK

    KxxkK

    2*2*

    0

    2

    )(

    (37)

    One integrates directly the equation (37) and

    one obtains the mother equation (38).

    Cy

    mx

    m

    xxky

    kK

    KxkK

    TS

    2

    '

    2

    '

    22)(

    22*

    22*

    0

    222

    (38)

    With the initial condition, at the =0, y=y=0and x=x=0, one obtains for the constant ofintegration, C the value 0. In this case the

    equation (38), takes the form (39).

    2

    '

    2

    '

    22)(

    22*

    22*

    0

    222

    ym

    xm

    xxky

    kK

    KxkK

    TS

    (39)

    The equation (39) can be put in the form (40),

    if one divides it with the2

    kK .

    0)(

    '

    '2

    2

    2

    22

    2*

    2

    2*

    02

    ykK

    Ky

    kK

    m

    xkK

    mx

    kK

    xkx

    T

    S

    (40)

    The mother equation (40), take the form (41),

    if one notes: '' ykK

    Kx

    , (the static

    assumption, Fm=Fr).

    0')(

    )(

    )(2

    22

    **

    2

    2

    2

    2

    2

    02

    ykK

    mm

    kK

    K

    ykK

    Kx

    kK

    xkx

    TS

    (41)

    Solving the Mother Equation (41) Directly

    The equation (41) is a two degree equation in

    x; One determines directly, (42-43) and X1,2(44) [13].

    22

    *

    2

    2

    *

    2

    22

    0 ')(

    )(

    )(

    )()(y

    kK

    mkK

    Km

    kK

    sKxk TS

    (42)

    22

    *

    2

    2*

    2

    22

    0 )'()(

    )(

    )(

    )()(Ds

    kK

    mkK

    Km

    kK

    Kskx TS

    (43)

    kK

    xkX 02,1 (44)

    Physically, just the positive solution is valid

    (see the relation 45).

    kK

    xkX

    0 (45)

    Solving the Mother Equation (41) with

    Finished Differences

    One can solve the mother equation (41) using

    the finished differences [13]. One notes:

    XsX (46)

    With the notation (46) placed in the mother

    equation (41), it obtains the equation (47).

    0')(

    )(

    )(

    222)(

    22

    **

    2

    2

    2

    2

    2

    0022

    ykK

    mmkK

    K

    skK

    K

    XkK

    xks

    kK

    xkXsXs

    TS

    (47)

    The equation (47) is a two degree equation in

    X, which can be solved directly with (49) and

    X1,2, (50), or transformed in a single degree

    equation in X, with (X)20, solved by the

    relation (48).

  • 8/10/2019 Cam Dynamic Synthesis

    6/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    6

    20

    22**2

    0

    22

    )()(2

    )'(])([)(2)2(

    )1(

    kKkK

    xks

    DsmkKmkK

    KskKkxskKk

    X

    TS

    (48)

    2

    22**2

    2

    0

    222

    )(

    )'(])([

    kK

    DsmkKmkK

    KxksK TS

    (49)

    )( 0

    kK

    xksX

    (50)

    2.3.Mechanism with Rotary Cam and

    Translated Tappet with Roll

    First, one presents an original method todetermine the efficiency at the mechanism withrotary cam and translated follower with roll [5].

    With this occasion it presents and the forcesand the velocities as well (Figure 3).

    The pressure angle (Figure 3), is determinedby relations (1.5-1.6).

    We can write the next forces, speeds andpowers (1.13-1.18).

    Fm(vm) is perpendicular to the vector rAat A.Fmis divided into Fa(the sliding force) and Fn

    (the normal force). Fn is divided too, into Fi (the

    bending force) and Fu (the useful force). Themomentary dynamic efficiency can be obtained

    from relation (1.18).

    0A

    A

    B

    A-

    Fn, vn

    Fm, vm

    Fa, va

    Fi, viFn, vn

    Fu, v2

    B

    B0

    A0

    A

    O

    x

    e

    s0

    rb

    r0

    rA

    rB

    s

    n

    C

    rb

    Fig. 3. Forces and velocities at the cam with

    translated follower with roll.

    The written relations are the following.

    2

    0

    22

    B s)(ser ... (1.1)

    2

    BB rr ...(1.2)

    B

    Bre sincos ...(1.3)

    B

    Br

    ss 0cossin ...(1.4)

    22

    0

    0

    )'()(cos

    esss

    ss

    ...(1.5)

    22

    0 )'()(

    'sin

    esss

    es

    ...(1.6)

    sinsincoscos)cos( ...(1.7)

    )cos(2

    )cos()sin(

    222

    2

    0

    22

    BbbBA

    bbA

    rrrrr

    rssrer

    ...(1.8)

    A

    b

    A

    A

    b

    A

    r

    re

    esssr

    esressse

    sin

    cos

    )'()(

    )'()'()(cos

    22

    0

    22

    0

    ...(1.9)

    A

    bA

    A

    b

    A

    r

    rss

    esssr

    resssss

    cossin

    )'()(

    ])'()([)(sin

    0

    22

    0

    22

    00

    ...(1.10)

    cos'

    )cos(

    )'()(

    ')()cos( 22

    0

    0

    A

    A

    A

    A

    r

    s

    esssr

    sss

    ...(1.11)

    2cos'

    cos)cos( A

    Ar

    s ...(1.12)

    )sin(

    )sin(

    Ama

    Ama

    FF

    vv ...(1.13)

  • 8/10/2019 Cam Dynamic Synthesis

    7/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    7

    )cos(

    )cos(

    Amn

    Amn

    FF

    vv ...(1.14)

    sin

    sin

    ni

    ni

    FF

    vv ...(1.15)

    cos)cos(cos

    cos)cos(cos2

    Amnu

    Amn

    FFF

    vvv

    ...(1.16)

    mmc

    Ammuu

    vFP

    vFvFP 222 cos)(cos

    ...(1.17)

    4

    2

    2

    222

    22

    cos'

    ]cos'[]cos)[cos(

    cos)(cos

    A

    i

    A

    Ai

    mm

    Amm

    c

    ui

    r

    s

    r

    s

    vF

    vF

    P

    P

    ...(1.18)

    bB rrr 00 (1.19)

    22

    00

    ers B (1.20)

    0

    0cosBr

    e (1.21)

    0

    0

    0sinBr

    s (1.22)

    2.4.The Relations to Design the Profile

    Now one determines the profile of the cam(relations 1.23-1.28).

    0 A (1.23)

    00 sinsincoscoscos AA

    (1.24)

    00 sincoscossinsin AA (1.25)

    A (1.26)

    sinsincoscoscos A (1.27)

    cossincossinsin A (1.28)

    2.5.The Exact Kinematics of B Module

    From the triangle OCB (fig. 3) the length rB

    (OB) and the complementary angles B (COB)

    and (CBO) are determined by the relation (1.1-1.4).

    From the general triangle OAB, where oneknows OB, AB, and the angle between them, B

    (ABO, which is the sum of with ), the length

    OA and the angle (AOB) can be determinedwith the relations (1.7-1.8, 1.29-1.31):

    BA

    bBA

    rr

    rrr

    2

    cos222

    (1.29)

    cossincossin)sin( ...(1.30)

    )sin(sin A

    b

    r

    r (1.31)

    With B and we can deduce now A and

    A (the relations 1.32-1.33):

    BA (1.32)

    BA (1.33)

    From (1.3) one obtains B (1.37), (see 1.34-

    1.37) where Br (1.36) can be deduced from (1.1).

    Then, (1.38) will be obtained from (1.29):

    2sin

    B

    B

    BBr

    re

    (1.34)

    2

    0 )( B

    BB

    Brss

    rre

    (1.35)

    sssrr

    sssrr

    BB

    BB

    )(

    )(22

    0

    0 (1.36)

    22

    0

    0

    )(

    )(

    BB

    Br

    se

    rss

    ssse

    (1.37)

    BBAABA

    BABA

    rrrrrr

    rrrr

    22sin2

    cos2cos2

    (1.38)

    From (1.38) one writes (1.43), but it is

    necessary to obtain first Ar (1.39) fromexpression (1.8):

  • 8/10/2019 Cam Dynamic Synthesis

    8/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    8

    )()sin(2

    )cos(222

    Bb

    BbBBAA

    rr

    rrrrrr

    (1.39)

    To solve (1.39) we need the derivatives

    (1.40 and 1.41) and (1.42).

    22

    0

    0

    )'()(

    )'(')('''

    esss

    essess

    (1.40)

    ' (1.41)

    2

    B

    Br

    se

    (1.42)

    Now we can determine

    (1.43), A

    (1.33)and A

    (1.44):

    sin

    coscos

    BA

    BBAABABA

    rr

    rrrrrrrr

    (1.43)

    AA (1.44)

    We write cos A and sin A (1.9-1.10):

    Further, we can obtain the expression cos(A-

    ) (1.11), and cos(A-).cos(1.12).

    Finally the forces and the velocities arededuced as follows (1.13-1.16):

    2.6.Determining the Efficiency of the

    Module B

    With the relationships (1.17-1.18) we candetermine the powers and the momentarymechanical efficiency [14].

    Determining the (Dynamic) Transmission

    Function D, for the Module B

    The followers velocity (1.16) can be writteninto the form (1.45).

    22

    22

    2

    cos'cos'

    cos'

    cos'

    cos)cos(cos

    ss

    r

    sr

    r

    sv

    vvv

    IAA

    A

    AA

    A

    m

    Amn

    (1.45)

    With the relationships (1.45) and (1.46) we

    determine the transmission function (the dynamicmodulus), D (1.47):

    Dsv '2 (1.46)

    2cos IAD (1.47)

    Expression cos2is known (1.48):

    22

    0

    2

    02

    )'()(

    )(cos

    esss

    ss

    (1.48)

    The expression of the A (1.49) is moredifficult.

    ]}')[(2

    )'()(

    ])/{[(

    /])'()/[(]})'(

    )()'(')(''[

    )'()(])'(

    ){[(])'()(

    ')[(

    22

    0

    22

    0

    222

    0

    22

    0

    2

    2

    00

    22

    0

    2

    2

    0

    22

    0

    22

    0

    seessr

    esss

    ress

    essses

    ssesssssr

    essses

    ssesss

    rseess

    b

    b

    b

    b

    I

    A

    (1.49)

    We will determine by its expressions (1.50-1.51):

    22

    0

    220

    22

    0

    22

    0

    22

    0

    )'()(

    ]')[(

    )'()(

    )'()(])[(

    cos

    esssrr

    seessr

    esssrr

    esssess

    BA

    b

    BA

    (1.50)

    22

    0

    0

    )'()(

    ')(sin

    esssrr

    sssr

    BA

    b

    (1.51)

  • 8/10/2019 Cam Dynamic Synthesis

    9/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    9

    The Dynamics of Distribution Mechanisms

    with Translated Follower with Roll

    For the dynamics of the Module B therelationships (49-50) are used in the forms (1.52-1.54), where D is determined from (1.47).

    ][2

    '

    ])(

    [2

    )(

    2

    0

    2

    2**

    2

    2

    02

    2

    2

    kK

    kxs

    ykK

    mmkK

    K

    skK

    kxs

    kK

    kKk

    X

    TS

    (1.52)

    ][2

    )'(

    ])(

    [2

    )(

    2

    0

    2

    2**

    2

    2

    02

    2

    2

    kK

    kxs

    sDkK

    mmkK

    K

    skK

    kxs

    kK

    kKk

    X

    TS

    (1.53)

    XsX (1.54)

    2.7.The Dynamic Analysis of the Module B

    It presents now the dynamics of the module Bfor some knownmovement laws.

    We begin with the classical law SIN (see thediagram in Figure 4); A speed rotation n=5500[rot/min], for a maxim theoretical displacement of

    the valve h=6 [mm] is used.Thephaseangle is u=c=65 [degree]; the ray

    of the basic circle is r0=13 [mm].For the ray of the roll the value rb=13 [mm]

    has been adopted.

    Fig. 4. The dynamic analysis of the module B. The

    law SIN, n=550 rpm, u=650

    , r0=13 [mm], rb=13[mm], hT=6 [mm], e=0 [mm],k=30 [N/mm], and

    x0=20 [mm].

    Fig.5. The profile SIN at the module B. n=5500 rpm

    u=650, r0=13 [mm], rb=13 [mm], hT=6 [mm].

    The dynamics are better than for the classical

    module C. For a phase angle of just 65 degrees theaccelerations have the same values as for theclassical module C for arelaxedphase (750-800).

    In Figure 5 we can see the cams profile. Ituses the profile sin, a rotation speed n=5500 rpm,

    and u=650, r0=13 [mm], rb=13 [mm], hT=6 [mm].

    The law COS can be seen in the Figures 6 and

    7. In the Figure 6 is presented the dynamicanalyze of the profile cos, and its profile designcan be seen in the Figure 7.

    The principal parameters are:

    Law COS, n=5500 rpm, u=650, r0=13 [mm],

    rb=6 [mm], hT=6 [mm], =10.5%.

    Fig. 6. The dynamic analysis of the module B. LawCOS, n=5500 rpm, u=65

    0, r0=13 [mm], rb=6 [mm],

    hT=6 [mm], =10.5%.

  • 8/10/2019 Cam Dynamic Synthesis

    10/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    10

    Fig. 7. The profile COS at the module B, n=5500

    rpm, u=650

    , r0=13 [mm], rb=6 [mm], hT=6 [mm].

    Fig. 8. The dynamic analysis. Law C4P1-0, n=5500

    rpm, u=800, r0=13 [mm], rb=6 [mm], hT=6 [mm].

    In the figure 8 the law C4P, created by the

    author, is analyzed dynamic. The vibrations arediminished, the noises are limited, the effectivedisplacement of the valve is increased, smax=5.37

    [mm].

    Fig. 9. The profile C4P of the module B.

    The efficiency has a good value =8.6%. In theFigure 9 the profile of C4P law is presented.

    It starts at the law C4P with n=5500 [rpm], butfor this law the rotation velocity can increase tohigh values of 30000-40000 [rpm] (see the Figure10).

    Fig. 10. The dynamic analysis of the module B. Law

    C4P1-5, n=40000 rpm.

  • 8/10/2019 Cam Dynamic Synthesis

    11/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    11

    2.8.The New Cam Synthesis

    The rotary cam with translated follower withroll (Figure 3 or 13), is synthesized dynamic bythe new next relationships.

    It has exchanged the rotation sense from the

    Figure 1 to Figure 11, from the clockwise to thecounter-clockwise.

    First, one determines the mass moment ofinertia (mechanical) of the mechanism, reduced tothe element of rotation, ie cam (basically usingkinetic energy conservation, system 2.1).

    2

    22

    0

    2

    0

    2

    2

    00

    2

    0

    2*

    2

    0

    22

    2

    0

    2

    0

    2

    0

    2

    0

    2

    00

    22

    0

    *

    22

    0

    22

    0

    2

    02

    0

    222

    22

    0

    00

    22

    0

    2

    0

    222

    0

    2

    0

    222

    0

    222

    0

    2222222

    2

    ''

    '

    2

    122

    2

    1

    8

    22

    22

    2

    1

    16

    1

    4

    1

    2

    1

    '

    '2

    '

    2

    '2

    '

    '2

    cossin2

    cos2cos

    sin2sin

    2

    1

    smesss

    sseserM

    sMssMrrrrMJ

    hm

    ehh

    s

    hse

    he

    rM

    hMhsMrrrrMJ

    esss

    eser

    esss

    ssrssrer

    esss

    ssssr

    esss

    eserssrer

    sserssrer

    ssrrss

    rereyxrR

    RMJ

    Tbc

    ccbbc

    Tbc

    ccbbcm

    b

    bbA

    b

    bbA

    bbA

    bb

    bbAAA

    ccama

    ...(2.1)

    We considered the law of motion of the tappetclassic version already used the cosine law (bothascending and descending).

    The angular velocity is a function of the cam

    position () but also its rotation speed (2.2).

    Where mis the nominal angular velocity of camand express at the distribution mechanisms basedon the motor shaft speed (2.3).

    2

    *

    *2

    m

    m

    J

    J ...(2.2)

    60260

    2

    6022

    nn

    n

    motor

    ccm

    ...(2.3)

    We start the simulation with a classical law ofmotion, namely the cosine law. To climb cosinelaw system is expressed by the relationships (2.4).

    uu

    r

    uu

    r

    uu

    r

    u

    hs

    has

    hvs

    hhs

    sin2

    '''

    cos2

    ''

    sin2

    '

    cos22

    3

    3

    2

    2

    ...(2.4)

    Where takes values from 0 to u.

    Jmaxoccurs for =u/2.With the relation (2.5) is expressed the first

    derivative of the reduced mechanical moment ofinertia. It is necessary to determine the angularacceleration (2.6).

    2/3220

    0

    2

    0

    2

    2/322

    0

    22

    00

    0

    *'

    '

    '''''

    '

    ''2''

    '''2''

    esss

    sesssssseserM

    esss

    essssssserM

    ssmssMssMJ

    bc

    bc

    Tcc

    ...(2.5)

    Differentiating the formula (2.2), against time,is obtained the angular acceleration expression(2.6).

    *

    *'2

    2 J

    J

    ...(2.6)

    Relations (2.2) and (2.6) a general nature andare basically two original equations of motion,crucial for mechanical mechanisms.

    For a rotary cam and translated tappet with rollmechanism (without valve), dynamic movementtappet is expressed by equation (2.7), which is an

  • 8/10/2019 Cam Dynamic Synthesis

    12/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    12

    original dynamic equation deduced for the

    distribution mechanism (50) and now bycanceling the valve mass, will customize and

    reaching form below (2.7).

    kK

    xkskK

    skKxksKkksmkK

    sx

    T

    02

    0

    2222

    )(2

    )(2)2(')(

    ...(2.7)

    Where x is the dynamic movement of thepusher, while s is its normal, kinematicsmovement. K is the spring constant of the system,

    and k is the spring constant of the tappet spring.It note, with x0the tappet spring preload, with

    mT the mass of the tappet, with the angularrotation speed of the cam (or camshaft), where sis the first derivative in function of of the tappet

    movement, s. Differentiating twice successively,the expression (2.7) in the angle , we obtain areduced tappet speed (equation 2.8), and reducedtappet acceleration (2.9).

    2

    02

    0

    0

    22

    0

    2222

    2

    ''

    '

    '2'22'''2

    )(2)2(')(

    kK

    kxskK

    Msx

    sNkK

    kxs

    skKkxsskKkssmkKM

    skKxksKkksmkKN

    T

    T

    (2.8)

    3

    02

    00

    0

    22

    22

    0

    0

    22

    0

    2222

    2

    '2''

    ''''

    ''2'''22

    ''''''2

    '

    '2'22'''2

    )(2)2(')(

    kK

    kxskK

    sMkK

    kxssN

    kK

    kxsO

    sx

    skKxksssKkk

    sssmkKO

    sNkK

    kxs

    skKkxsskKkssmkKM

    skKxksKkksmkKN

    T

    T

    T

    (2.9)

    Further the acceleration of the tappet can be

    determined directly real (dynamic) using therelation (2.10).

    ''' 2 xxx ...(2.10)

    3. New Dynamic Synthesis

    Give the following parameters:r0=0.013 [m]; rb=0.005 [m]; h=0.008 [m]; e=0.01

    [m]; x0=0.03 [m]; u=/2; c=/2; K=5000000[N/m]; k=20000 [N/m]; mT=0.1 [kg]; Mc=0.2[kg]; nmotor=5500 [rot/min].

    To sum up dynamically based on a computer

    program, you can vary the input data until thecorresponding acceleration is obtained (see Figure11). It then summarizes the corresponding cam

    profile (Figure 12) using the relations (2.11).

    Fig. 11. Dynamic diagram to the rotary cam with

    translated follower with roll.

    coscossinsin

    sincoscossin

    cossin

    sincos

    cos

    sin

    0

    0

    0

    bbC

    bbC

    TTC

    TTC

    bT

    bT

    rssrey

    rssrex

    yxy

    yxx

    rssy

    rex

    ...(2.11)

  • 8/10/2019 Cam Dynamic Synthesis

    13/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    13

    Fig. 12. The cam profile to the rotary cam with

    translated follower with roll; rb=0.003 [m]; e=0.003

    [m]; h=0.006 [m]; r0=0.013 [m]; 0=/2 [rad];.

    3.1.

    The New Geometry of the Rotary Camand the Translated Follower with Roll

    Now, we shall see the geometry of a rotarycam with translated follower with roll (Figure 13).The cam rotation sense is positive (trigonometric).

    We can make the geometrical synthesis of thecam profile with the help of the cinematics of themechanism. One uses as well the reduced speed,s. OA=r=rA; r

    2=rA2

    It establishes a system fixed Cartesian, xOy =xfOyf, and a mobil Cartesian system, xOy =

    xmOymfixed with the cam.From the lower position 0, the tappet, pushed

    by cam, uplifts to a general position, when the

    cam rotates with the angle. The contact point A,

    go from Ai0 to A

    0(on the cam), and to A (on the

    tappet). The position angle of the point A from the

    tappet is f, and from the cam is m. We candetermine the coordinates of the point A from thetappet (2.12), and from the cam (2.13).

    ffAbfAT

    ffAb

    f

    AT

    rrrssyy

    rrrexx

    sinsincos

    coscossin

    0

    ...(2.12)

    sinsincoscossincos

    cossincossinsinsin

    sincoscossinsincos

    sinsincoscoscoscos

    0

    0

    bbTT

    fffmA

    m

    Ac

    bbTT

    fffmA

    m

    Ac

    rerssxy

    rrrryy

    rssreyx

    rrrrxx

    (2.13)

    f

    m

    A

    0

    iA

    0AO

    fx

    fy

    mx

    0B

    B

    e

    s

    0s

    r

    0r

    0r

    br

    br

    Br

    0

    Fig. 13. The geometry of the rotary cam with

    translated follower with roll.

    One uses and the next relationships (2.14),

    where the pressure angle was obtained with theclassic Antonescu P. method [2].

    22

    0

    22

    0

    0

    22

    00

    '

    'sin

    'cos

    esss

    es

    esss

    ss

    errs b

    ...(2.14)

    3.2.Determining the Forces, the Velocities

    and the Efficiency

    The driving force Fm, perpendicular on r in A,is divided in two components: Fn, the normalforce, and Fa, a force of slipping. Fn is divided, aswell, in two components: FTis the transmitted (theutile) force, and FR is a radial force which bend

    the tappet (see 2.15, and the Figure 14).

  • 8/10/2019 Cam Dynamic Synthesis

    14/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    14

    cossin2

    cossin

    ;;2

    cos

    ;22

    ;

    coscoscoscos

    coscoscoscos

    coscoscos

    coscoscos

    cos

    cos

    0

    2

    0

    22

    2

    0

    222

    2

    0

    2222

    222

    sserssrerr

    rssreyxr

    sserrr

    rrrA

    AA

    vF

    vF

    vF

    vF

    P

    P

    vvv

    FFF

    vv

    FF

    bbA

    bbAfAf

    B

    b

    Bb

    mm

    mm

    mm

    TT

    c

    ui

    mnT

    mnT

    mn

    mn

    (2.15)

    f

    m

    A

    0

    iA

    0A

    O

    fx

    fy

    mx

    0B

    B

    e

    s

    0s

    r

    0r

    0r

    br

    br

    Br

    0

    TF

    RF

    nF

    nF

    mF

    aF

    Fig.14. Forces and velocities of the rotary cam withtranslated follower with roll.

    3.3.New Geometro-Kinematics Synthesis

    For a good work one proposes to make a newgeometric and kinematics synthesis of the camprofile, using some new relationships for thepressure angle delta (2.16). The new synthesisrelations already presented (2.12 and 2.13) willuse delta pressure angle, deduced now with new

    relationship (2.16).

    ffAb

    f

    AT

    ffAb

    f

    AT

    rrrssyy

    rrrexx

    sinsincos

    coscossin

    0

    ...(2.12)

    sinsincoscossincos

    cossincossinsinsin

    sincoscossinsincos

    sinsincoscoscoscos

    0

    0

    bbTT

    fffmA

    m

    Ac

    bbTT

    fffmA

    m

    Ac

    rerssxy

    rrrryy

    rssreyx

    rrrrxx

    (2.13)

    One uses and the next relationships (where the

    pressure angle was obtained with the newmethod):

    ][2

    '2'4'4arccossinsin

    ][2

    '2'4'4arccos

    cosarccos

    ][2

    '2'4'4cos

    22

    0

    22

    00

    2

    0

    22

    0

    22

    00

    2

    0

    22

    0

    22

    00

    2

    0

    22

    00

    ess

    sesesssssss

    ess

    sesesssssss

    ess

    sesesssssss

    errs b

    ...(2.16)

    The new profile can be seen in the Figure 15.

    Fig. 15. The new cam profile to the rotary cam with

    translated follower with roll; rb=0.003 [m]; e=0.003

    [m]; h=0.006 [m]; r0=0.013 [m]; 0=/2 [rad];

  • 8/10/2019 Cam Dynamic Synthesis

    15/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    15

    3.4.Demonstration (Explication)

    The original relationships (2.16) have beendeduced by the expressions (2.17).

    Classical method uses to the geometricsynthesis and the reduced tappet velocity, and in

    this mode the geometric classic method become ageometric and kinematic synthesis method. Thenew geometric synthesis method uses just thegeometric parameters (without velocities), but oneutilizes and a condition to realize at the tapped thevelocities predicted by the tapped movement lawsimposed by the cam profile.

    ][2

    '2'4'4cos

    ][2

    '4'2'2cos

    0'cos'2cos

    cos'2cos'coscos

    cos'cos1cos

    coscossin'cossin

    cos

    '

    cossincossincossinsin

    sincos

    'sin

    cos

    '

    sinsin

    sincos

    '

    sin

    2

    cos

    2

    coscos

    22;;

    2

    coscos'coscos

    22

    0

    22

    00

    2

    0

    22

    0

    22

    0

    222

    0

    2

    02

    222

    0

    422

    0

    242242

    0

    22

    0

    22

    0

    2

    00

    0

    ess

    sesesssssss

    ess

    essssessesss

    ssessess

    seesssss

    esss

    esssr

    ess

    r

    s

    r

    e

    r

    ssBBB

    Br

    sB

    r

    r

    r

    s

    Br

    rA

    Ar

    s

    AAA

    AA

    rsrs

    BB

    BB

    BA

    B

    A

    A

    B

    A

    AA

    ...(2.17)

    Then, it makes the dynamic analyze for theimposed cam profile, and one modify the cam

    profile geometric parameters to determine a gooddynamic response (functionality). In this mode it

    realizes the dynamic synthesis of the cam, and weobtain a normal functionality. The synthesis wasmade using the natural geometro-kinematicsparameters (of cam mechanism). It follows the

    proper functioning dynamics. We will optimizeand the couple cam-pusher efficiency. Forces,velocities and accelerations are also limited.

    3.5.Increasing the mechanical efficiency at

    the Rotary Cam and Translated

    Follower with Roll

    The used law is the classical law (2.4), cosinelaw.

    The synthesis of the cam profile can be madewith the relationships (3.1) when the cam rotatesclockwise and with the expressions from the

    system (3.2) when the cam rotates

    counterclockwise (trigonometric).

    sinsincoscos

    sincoscossin

    0

    0

    bbC

    bbC

    rerssy

    rssrex

    (3.1)

    sinsincoscos

    sincoscossin

    0

    0

    bbc

    bbc

    rerssy

    rssrex

    ...(3.2)

    The r0(the radius of the base circle of the cam)is 0.013 [m]. The h (the maximum displacement

    of the tappet) is 0.020 [m]. The angle of lift, uis/3 [rad]. The radius of the tappet roll is rb=0.002[m]. The misalignment is e=0 [m]. The cosine

    profile can be seen in the fig. 16.

    Fig. 16. The cosine profile at the cam with

    translated follower with roll; r0=13[mm],

    h=20[mm], u=/3[rad], rb=2[mm], e=0[mm].

    The obtained mechanical yield (obtained byintegrating the instantaneous efficiencythroughout the climb and descent) is 0.39 or

    =39%. The dynamic diagram can be seen in thefig. 17 (the dynamic setting are partial normal).Valve spring preload 9 cm no longer poses today.

    Instead, achieve a long arc very hard(k=500000[N/m]), require special technologicalknowledge.

  • 8/10/2019 Cam Dynamic Synthesis

    16/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    16

    Fig. 17. The dynamic diagram at the cosine

    profile at the cam with translated follower with

    roll; r0=13[mm]; h=20[mm]; u=/3[rad];

    rb=2[mm]; e=0[mm]; n=5500[rpm]; x0=9[cm];

    k=500[kN/m]

    It tries increase the yield [8-9, 15-16]; angle of

    climb is halved u=/6[rad] (see the profile in theFig. 18).

    The r0(the radius of the base circle of the cam)is 0.015 [m]. The h (the maximum displacementof the tappet) is 0.010 [m]. The angle of lift, uis

    /6 [rad]. The radius of the tappet roll is rb=0.002[m]. The misalignment is e=0 [m]. The cosineprofile can be seen in the Fig. 18.

    Fig. 18. The cosine profile at the cam with

    translated follower with roll; r0=15[mm],

    h=10[mm], u=/6[rad], rb=2[mm], e=0[mm].

    The obtained mechanical yield (obtained by

    integrating the instantaneous efficiencythroughout the climb and descent) is 0.428 or

    =43%. The dynamic diagram can be seen in thefig. 19 (the dynamic setting are not normal).Valve spring preload 20 cm no longer poses

    today. Instead, achieve a long arc very-very hard(k=1500000[N/m]), require special technologicalknowledge.

    Fig. 19. The dynamic diagram at the cosine profile

    at the cam with translated follower with roll;

    r0=15[mm]; h=10[mm]; u=/6[rad]; rb=2[mm];

    e=0[mm]; n=5500[rpm]; x0=20[cm]; k=1500[kN/m]

    Camshaft runs at a shaft speed halved (nc=n/2).

    If we more reduce camshaft speed by threetimes (nc=n/6), we can reduce and the preload ofthe valve spring (x0=5[cm]); see the dynamicdiagram in the Fig. 20. However, in this case, thecam profile should be tripled (see the Fig. 21).

    -1400

    -1200

    -1000

    -800

    -600

    -400

    -200

    0

    200

    400

    600

    0 50 100 150 200 250 300 350 400

    xpp [m/s2]

    xpp [m/s2]

    -1400

    -1200

    -1000

    -800

    -600

    -400

    -200

    0

    200

    400

    600

    0 50 100 150 200 250 300

    xpp [m/s2]

    -1400

    -1200

    -1000

    -800

    -600

    -400

    -200

    0

    200

    400

    600

    0 50 100 150

    Fig. 20. The dynamic diagram at the cosine tripled

    profile at the cam with translated follower with

    roll; r0=15[mm]; h=10[mm]; u=/6[rad];rb=2[mm]; e=0[mm]; n=5500[rpm]; x0=5[cm];

    k=1500[kN/m].

  • 8/10/2019 Cam Dynamic Synthesis

    17/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    17

    Fig. 21. The cosine tripled profile at the cam withtranslated follower with roll; r0=15[mm],

    h=10[mm], u=/6[rad], rb=2[mm], e=0[mm].

    It tries increase the yield again; angle of climb

    is reduced to the value u=/8[rad].

    The r0(the radius of the base circle of the cam)is 0.013 [m].

    The h (the maximum displacement of thetappet) is 0.009 [m].

    The angle of lift, uis /8 [rad].The radius of the tappet roll is rb=0.002 [m].The misalignment is e=0 [m]. The cosine

    profile can be seen in the fig. 22.

    Fig. 22. The cosine profile at the cam with

    translated follower with roll; r0=13[mm], h=9[mm],

    u=/8[rad], rb=2[mm], e=0[mm].

    The obtained mechanical yield (obtained byintegrating the instantaneous efficiency

    throughout the climb and descent) is 0.538 or=54%. The dynamic diagram can be seen in thefig. 23 (the dynamic setting are not normal).Valve spring preload 30 cm no longer posestoday. Instead, achieve a long arc very-very hard(k=1600000[N/m]), require special technologicalknowledge.

    Fig. 23. The dynamic diagram at the cosine profile

    at the cam with translated follower with roll;

    r0=13[mm]; h=9[mm]; u=/8[rad]; rb=2[mm];

    e=0[mm]; n=5000[rpm]; x0=30[cm]; k=1600[kN/m]

  • 8/10/2019 Cam Dynamic Synthesis

    18/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    18

    Camshaft runs at a shaft speed halved (nc=n/2).

    If we more reduce camshaft speed by four times(nc=n/8), we can reduce and the preload of the

    valve spring, x0=9[cm] and the elastic constant ofthe valve spring, k=15000[N/m]; see the dynamicdiagram in the Fig. 24. However, in this case, the

    cam profile should be fourfold (see the Fig. 25).

    -4000

    -3000

    -2000

    -1000

    0

    1000

    2000

    3000

    4000

    0 50 100 150 200 250 300 350 400

    xpp [m/s2]

    xpp [m/s2]

    -4000

    -3000

    -2000

    -1000

    0

    1000

    2000

    3000

    4000

    0 50 100 150 200 250 300 350 400

    xpp [m/s2]

    -4000

    -3000

    -2000

    -1000

    0

    1000

    2000

    3000

    4000

    0 50 100 150 200

    xpp [m/s2]

    -4000

    -3000

    -2000

    -1000

    0

    1000

    2000

    3000

    4000

    0 50 100 150 200 250 300

    xpp [m/s2]

    Fig. 24. The dynamic diagram at the cosine fourfold

    profile at the cam with translated follower with roll;

    r0=13[mm]; h=9[mm]; u=/8[rad]; rb=2[mm];

    e=0[mm]; n=5000[rpm]; x0=9[cm]; k=15[kN/m]

    Fig. 25. The cosine fourfold profile at the cam with

    translated follower with roll; r0=13[mm], h=9[mm],

    u=/8[rad], rb=2[mm], e=0[mm].

    With the same angle of climb u=/8[rad], canincrease performance even further, if the sizetappet race take a greater value (h=12[mm]). Ther0 (the radius of the base circle of the cam) is0.013 [m].

    The h (the maximum displacement of the

    tappet) is 0.012 [m]. The angle of lift, u is /8[rad]. The radius of the tappet roll is rb=0.002 [m].The misalignment is e=0 [m]. The cosine profile

    can be seen in the fig. 26.

    Fig. 26. The cosine profile at the cam with

    translated follower with roll; r0=13[mm],

    h=12[mm], u=/8[rad], rb=2[mm], e=0[mm].

    For correct operation it is necessary todecrease the speed of the camshaft four times, andall four times multiplication of the cam profile.Camshaft runs at a shaft speed halved (nc=n/2). Ifwe more reduce camshaft speed by four times

    (nc=n/8), we can reduce and the preload of thevalve spring, x0=9[cm]. The elastic constant of thevalve spring is k=1500000[N/m]. See the dynamicdiagram in the Fig. 27. However, in this case, thecam profile should be fourfold. The obtained

    mechanical yield is 0.60 or =60%.

  • 8/10/2019 Cam Dynamic Synthesis

    19/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    19

    -2000

    -1500

    -1000

    -500

    0

    500

    0 50 100 150 200 250 300 350 400

    xpp [m/s2]

    xpp [m/s2]

    -2000

    -1500

    -1000

    -500

    0

    500

    0 50 100 150 200 250 300 350 400

    xpp [m/s2]

    -2000

    -1500

    -1000

    -500

    0

    500

    0 50 100 150 200 250 30

    xpp [m/s2]

    -2000

    -1500

    -1000

    -500

    0

    500

    0 50 100 150 200

    xpp

    Fig.27. The dynamic diagram at the cosine fourfoldprofile at the cam with translated follower with roll;

    r0=13[mm]; h=12[mm]; u=/8[rad]; rb=2[mm];

    e=0[mm]; n=5000[rpm]; x0=9[cm]; k=1500[kN/m]

    For now is necessary to stop here.If we increase h, or decrease the angle u, then

    is tapering cam profile very much. We must stop

    now at a yield value, =60%.

    Nomenclature

    M the mass of the mechanism, reduced

    at the valveK the elastically constant of the

    systemk the elastically constant of the valve

    spring

    dt

    dMc 2

    1

    the coefficient of the systemsamortization

    F0 the elastically force whichcompressing the valve spring

    rF the resistant force

    mF the motor forcex the effective displacement of the

    valvex0 the valve (tappet) spring preloadx the reduced valve (tappet) speedx the reduced valve (tappet)

    acceleration

    ys the theoretical displacement of thetappet reduced at the valve, imposedby the cams profile

    ys the velocity of the theoretical

    displacement of the tappet reducedat the valve, imposed by the camsprofile

    mT=m2 the mass of the tappet (of the valvelifter)

    m3 the mass of the valve push rod

    m5 the valve massJ1=Jc the inertia mechanical moment of

    the cam

    J4 the inertia mechanical moment ofthe valve rocker

    2y the tappet velocity, or the secondmovement-low, imposed by thecams profile

    x the real (dynamic) valve velocity

    x the real (dynamic) valveacceleration

    i=i25 the ratio of transmission tappet-valve, given from the valve rocker

    y the tappet velocity reduced at the

    valveD the dynamic transmission function(the dynamic transmissioncoefficient)

    m the nominal (average) angularvelocity of cam

    =1= the angular (real) rotation speed ofthe cam (or camshaft)

    4 the angular rotation speed of thevalve rocker

    The pressure angle

    The additional pressure angle

    rb roll radiusr0 basic radius

    e horizontally misalignments0 vertical misalignment

    BA rr , position vectors

    J* the reduced mechanical moment ofinertia

    J* the first derivative of the reducedmechanical moment of inertia

    J*m the average reduced moment of

    inertia

  • 8/10/2019 Cam Dynamic Synthesis

    20/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    20

    4. Discussion

    In this paper one presents an original methodto determine the dynamic parameters at thecamshaft (the distribution mechanisms). It makesthe synthesis, of the rotary cam and tappet with

    translational motion with roll, with a greatprecision.

    The authors introduce a new pressure angle,alpha, and a new method to determine the twopressure angles, alpha and delta.

    The presented method is the most elegant anddirect method to determine the kinematics anddynamic parameters.

    The dynamic synthesis can generate a camprofile which will work without vibrations.

    Processes robotization increasingly determineand influence the emergence of new industries,

    applications in specific environmental conditions,approach new types of technological operations,handling of objects in outer space, leadingteleoperator in disciplines such as medicine,robots that covers a whole larger service benefitsour society, modern and computerized. In thiscontext, this paper seeks to contribute to thescientific and technical applications in dynamicanalysis and synthesis of cam mechanisms.

    In 1971 K. Hain proposes an optimization

    method to cam mechanism to achieve the

    optimum output transmission angle (maximum)and minimum acceleration [11].In 1979 F. Giordana investigates the influence

    of measurement errors in kinematic analysis of

    cam [10].In 1985 P. Antonescu presents an analytical

    method for the synthesis mechanism flat tappetcam and tappet rocker mechanism [2].

    In 1987 F.I. Petrescu presents a new dynamic

    model with general applications [3].In 1988 J. Angelas and C. Lopez-Cajun

    presents optimal synthesis mechanism oscillating

    flat tappet cam and [1].In 1991 B.S. Bagepalli presents a generalized

    model of dynamic cam-follower pairs [4].In 1999 R.L. Norton studying the effect of

    valve-cam ramps on the valve-train dynamics[12].

    Z. Chang presents in 2001 [5] and 2011 [6] astudy on dynamics of roller gear cam system,considering clearances.

    In 2002 D. Taraza synthesized analyzes theinfluence of the cam profile, the variation of theangular velocity distribution tree, and the

    parameters of power load consumption andemissions of internal combustion engine [16].

    In 2005 [13] and 2008 [14], F.I. Petrescu and

    R.V. Petrescu present a synthesis method of rotarycam profile, and translational or rotary tappet, flat

    or with roll, to obtain high yields output.In 2009 K. Dan makes some research on

    dynamic behavior simulation technology for cam-

    drive mechanism in single-cylinder engines [7].In 2009 M. Satyanarayana makes a dynamic

    experiment in cam-follower mechanism [15].In 2011 Z. Ge makes the design and dynamic

    analysis of the cam mechanisms [8-9].

    5. Conclusions

    The distribution mechanisms work with smallefficiency for about 150 years; this fact affects thetotal yield of the internal heat engines. Much ofthe mechanical energy of an engine is lost throughthe mechanism of distribution. Multi-years theyield of the distribution mechanisms was only 4-8%. In the past 20 years it has managed a lift up tothe value of 14-18%; car pollution has decreasedand people have better breathing again.Meanwhile the number of vehicles has tripled andthe pollution increased again.

    Now, its the time when we must try again togrow the yield of the distribution mechanisms.

    The paper presents an original method to

    increase the efficiency of a mechanism with camand follower, used at the distribution mechanisms.This paper treats only one module: the

    mechanism with rotary cam and translated followerwith roll (the modern module B).

    At the classical module C we can increase againthe yield to about 30%. The growth is difficult.Dimensional parameters of the cam must be

    optimized; optimization and synthesis of the camprofile are made dynamic, and it must set theelastic (dynamic) parameters of the valve (tappet)spring: k and x0.

    The law used is not as important as the moduleused, sizes and settings used. We take the classicallaw cosine; dimensioning the radius cam, liftheight, and angle of lift.

    To grow the cam yield again we must leave theclassic module C and take the modern module B.In this way the efficiency can be as high as 60%.

    Yields went increased from 4% to 60%, andwe can consider for the moment that we have gainimportance, since we work with the cam andtappet mechanisms.

    If we more increase h, or decrease the angle

    u, then is tapering cam profile very much. Wemust stop now at a yield value, =60%.

  • 8/10/2019 Cam Dynamic Synthesis

    21/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    21

    It can synthesize high-speed cam, or high-

    performance camshafts.

    6. References

    [1]

    Angelas J., Lopez-Cajun C., Optimalsynthesis of cam mechanisms with oscillatingflat-face followers. Mechanism and MachineTheory 23,(1988), Nr. 1., p. 1-6., 1988.

    [2] Antonescu, P., Petrescu, F., Antonescu, O.,Contributions to the Synthesis of The RotaryDisc-Cam Profile, In VIII-th InternationalConference on the Theory of Machines andMechanisms, Liberec, Czech Republic, p. 51-56, 2000.

    [3] Antonescu, P., Oprean, M., Petrescu, F.I.,Analiza dinamic a mecanismelor dedistribuie cu came. n al VII-lea SimpozionNaional de Roboi Industriali, MERO'87,Bucureti, 1987, Vol. III, p. 126-133.

    [4] Bagepalli, B.S., a.o., Generalized Modelingof Dynamic Cam-follower Pairs inMechanisms, Journal of Mechanical Design,June 1991, Vol. 113, Issue 2, p. 102-109.

    [5] Chang, Z., a.o., A study on dynamics ofroller gear cam system consideringclearances, Mechanism and Machine Theory,

    January 2001, Vol. 36, N. 1, p. 143-152.

    [6]

    Chang, Z., a.o., Effects of clearance ondynamics of parallel indexing cammechanism, ICIRA11 Proceedings of the 4thinternational conference on Intelligent

    Robotics and Applications Volume, Part I,2011, p. 270-280.

    [7] Dan, K., a.o., Research on Dynamic BehaviorSimulation Technology for Cam-DriveMechanism in Single-cylinder Engines, SAE

    Technical Paper, 2009, paper number 2009-32-0089.

    [8] Ge, Z., a.o., Mechanism Design amd

    Dynamic Analysis of Hybrid Cam-linkageMechanical Press, Key EngineeringMaterials Journal, Vol. 474-476 (2011), p.803-806.

    [9] Ge, Z., a.o., CAD/CAM/CAE for the Parallel

    Indexing Cam Mechanisms, AppliedMechanics and Materials Journal, Vol. 44-47

    (2011), p. 475-479.[10] Giordana F., s.a., On the influence of

    measurement errors in the Kinematic

    analysis of cam. Mechanism and MachineTheory 14 (1979), nr. 5., p. 327-340, 1979.

    [11] Hain K., Optimization of a cam mechanismto give goode transmissibility maximaloutput angle of swing and minimalacceleration. Journal of Mechanisms 6(1971), Nr. 4., p.419-434.

    [12]Norton, R.L., a.o., Effect of Valve-CamRamps on Valve Train Dynamics, SAE,International Congress & Exposition, 1999,Paper Number 1999-01-0801.

    [13] Petrescu, F.I., Petrescu, R.V. Contributions

    at the dynamics of cams. In the NinthIFToMM International Symposium onTheory of Machines and Mechanisms,SYROM 2005, Bucharest, Romania, 2005,Vol. I, p. 123-128.

    [14] Petrescu F.I., .a., Cams DynamicEfficiency Determination. In New Trends

    in Mechanisms, Ed. Academica -Greifswald, 2008, I.S.B.N. 978-3-940237-10-1, p. 49-56.

    [15] Satyanarayana, M., a.o., Dynamic Responseof Cam-Follower Mechanism, SAE Technic

    Paper, 2009, paper number 2009-01-1416.[16] Taraza, D., "Accuracy Limits of IMEP

    Determination from Crankshaft SpeedMeasurements," SAE Transactions, Journalof Engines 111, p. 689-697, 2002.

  • 8/10/2019 Cam Dynamic Synthesis

    22/23

    Flor ian I on T. Petrescu Al -Khwarizmi Engineer ing Journal, Vol. 10, No. 1, P.P. 1- 23 (2014)

    22

    AUTHORSINFORMATION

    1Dr. Eng. Florian Ion T. Petrescu, Senior Lecturerat UPB (Bucharest Polytechnic University), TMR(Theory of Mechanisms and Robots) department.2Dr. Eng. Relly Victoria V. Petrescu, SeniorLecturer at UPB (Bucharest PolytechnicUniversity), TTL (Transport, Traffic andLogistics) department.

    1. Ph.D. Eng. Florian Ion T.PETRESCUSenior Lecturer at UPB (BucharestPolytechnic University), Theory of Mechanismsand Robots department,

    Date of birth: March.28.1958; Higher education:Polytechnic University of Bucharest, Faculty ofTransport, Road Vehicles Department, graduated

    in 1982, with overall average 9.63;

    Doctoral Thesis: "Theoretical and AppliedContributions About the Dynamic of PlanarMechanisms with Superior Joints".

    Expert in: Industrial Design, Mechanical Design,Engines Design, Mechanical Transmissions,Dynamics, Vibrations, Mechanisms, Machines,Robots.

    Association:

    Member ARoTMM, IFToMM, SIAR, FISITA,SRR, AGIR. Member of Board of SRRB(Romanian Society of Robotics).

    2. Ph.D. Eng. Relly Victoria V. PETRESCUSenior Lecturer at UPB (Bucharest PolytechnicUniversity), Transport, Traffic and Logisticsdepartment,

    Citizenship: Romanian;

    Date of birth: March.13.1958;Higher education: Polytechnic University ofBucharest, Faculty of Transport, Road Vehicles

    Department, graduated in 1982, with overallaverage 9.50;

    Doctoral Thesis: "Contributions to analysis andsynthesis of mechanisms with bars and sprocket".

    Expert in Industrial Design, EngineeringMechanical Design, Engines Design, Mechanical

    Transmissions, Projective and descriptivegeometry, Technical drawing, CAD, Automotiveengineering, Vehicles, Transportations.

    Association:Member ARoTMM, IFToMM, SIAR, FISITA,

    SRR, SORGING, AGIR.

  • 8/10/2019 Cam Dynamic Synthesis

    23/23

    101 82 -65(2014)F lor ian I on T. Petrescu

    Florian Ion T. Petrescu* Relly Victoria V. Petrescu** / / / *

    / / / **

    [email protected] *:

    [email protected] **:

    .

    .

    ()

    . .

    .

    mailto:[email protected]*%D8%A7%D9%84%D8%A8%D8%B1%D9%8A%D8%AFmailto:[email protected]*%D8%A7%D9%84%D8%A8%D8%B1%D9%8A%D8%AFmailto:[email protected]*%D8%A7%D9%84%D8%A8%D8%B1%D9%8A%D8%AFmailto:[email protected]*%D8%A7%D9%84%D8%A8%D8%B1%D9%8A%D8%AFmailto:[email protected]**%D8%A7%D9%84%D8%A8%D8%B1%D9%8A%D8%AFmailto:[email protected]**%D8%A7%D9%84%D8%A8%D8%B1%D9%8A%D8%AFmailto:[email protected]**%D8%A7%D9%84%D8%A8%D8%B1%D9%8A%D8%AFmailto:[email protected]**%D8%A7%D9%84%D8%A8%D8%B1%D9%8A%D8%AFmailto:[email protected]**%D8%A7%D9%84%D8%A8%D8%B1%D9%8A%D8%AFmailto:[email protected]**%D8%A7%D9%84%D8%A8%D8%B1%D9%8A%D8%AFmailto:[email protected]*%D8%A7%D9%84%D8%A8%D8%B1%D9%8A%D8%AFmailto:[email protected]*%D8%A7%D9%84%D8%A8%D8%B1%D9%8A%D8%AF

Recommended