【20160406】Kinematic inversion
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7 q+ A. Z* B8 K! A X1 M2 QThe cam will be imagined as being stationary.
. K. n/ y w- E1 y! P+ hThe follower then should be rotated opposite to the direction of cam rotation.
) `% u4 R4 ?4 Z5 E, X4 D3 wThe desired location for the follower, at several positions, is constructed from the base circle.
) l$ e J$ V- k1 z" f L假定凸轮不动,从动件沿相反方向转动,在基圆上画出从动件的几个预期运动位置。% }/ Z& s9 @5 [ c
4 t; r5 Z! Z) u& V+ u+ W* V% ~To creating the cam shape: wrapping the displacement diagram around the base circle.
* G: R& q% K. ?# |( f设计凸轮形状时,用从动件位移图上的位移将基圆“包裹”起来。. w0 x6 ]1 ^' A1 X( }) L, u! h
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6 f: `; L5 m. u具体例子:; l3 h) H4 t# f& N
① In-Line Knife-Edge Follower 对心直动尖顶从动件凸轮
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0 ?9 U+ ~, [' e1. Draw the base circle of radius.6 t, A* K- k) J
2. Draw the follower in the home position.1 E: x& I( o* F$ e6 [% Y3 }
3. Draw radial lines from the center of the cam, corresponding to the cam angles identified on the displacement diagram.9 Q: V1 U, U' S+ X3 P$ N
4. The follower will be rotated in a direction opposite to the actual cam rotation.
( }, p* R/ P0 w! @2 I" ]5 ]$ R5. Transfer the displacements from the displacement diagram to the radial lines.
$ }# I9 U) Z4 z; l6. Measure the displacements from the base circle.' i6 Y2 M9 F; f* s; {* a* }7 a+ s
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1.画出制定半径的基圆。0 D- E* |$ G1 x x- x- M7 v
2.画出初始位置的从动件。* M; U) P* t% p( a# N+ h4 d4 M
3.从中心画出基圆的径向线,角度与位移图上横轴凸轮角度相对应。; Z+ N% l) A. r& J6 E
4.从动件与凸轮真实运动方向相反。
# o; a y/ r: b, ~- ^% h/ H5.将位移移到径向线上。" ]0 {9 z& p* d0 G
6.测量从动件远离凸轮基圆的距离。
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② Offset Roller Follower 偏置滚轮从动件
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1. Draw the base circle of radius.$ C0 H% {# b N1 o
2. Draw the follower centerline in the home position./ Z/ K% @" k, Y! z0 ^1 k! T8 G
3. Draw the prime circle.
2 k. E# |8 y7 J Z5 M5 m* U4. Draw the follower in the home position of radius.
1 |) ?" w, I: E3 w5. Draw an offset circle of radius, which will be tangent to the follower centerline.
- ]4 M' d8 J3 t+ ~6. Draw lines tangent to the offset circle, corresponding to the reference cam angles on the displacement diagram.; h- s% g$ e. X( p2 B
7. The follower will be rotated in a direction opposite to the actual cam rotation.. q4 R# ?/ E, C% b; b8 I. n) F/ l
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1.画出制定半径的基圆。 Y5 b) V9 n5 _* i t
2.画出初始位置的从动件中心线。6 {! J7 T& x# y% i
3.画出理论廓线。
1 I' b+ D1 g3 @: E- ~7 u4.画出初始位置的从动件。$ D( L2 {! e6 p# Y' q- b& w# R
5.以偏心距为半径画圆,与从动件中心线相切。
( Z+ m4 Q1 T( a Y6 f& N& Z5 ~. L6.与偏距圆相切画线,角度与位移图上横轴凸轮角度相对应。7 y) B/ ?% d# a. g# S. B% C6 J
7.从动件与凸轮真实运动方向相反。
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