【20160406】Kinematic inversion. d ^. _1 b; F0 ]$ G7 Y* j2 v
运动倒置
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The cam will be imagined as being stationary.% h- D% n" h& p5 P. s0 W, ^
The follower then should be rotated opposite to the direction of cam rotation./ E3 A0 z* Y0 n+ Y
The desired location for the follower, at several positions, is constructed from the base circle.
( z$ u9 | {4 Q- x: p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。
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$ v5 D* x9 Z; b7 ?6 ITo creating the cam shape: wrapping the displacement diagram around the base circle.% X& h8 J! ^9 W( T$ B" p
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。. i+ h( U% ^( a5 ?( W0 B$ \" P3 y
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! @) P- a0 h- @/ r具体例子:& g8 y0 ?9 X, R
① In-Line Knife-Edge Follower 对心直动尖顶从动件凸轮) x* m& z0 a1 Y
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1. Draw the base circle of radius.9 v& m/ w+ m* |' K8 b
2. Draw the follower in the home position.8 @) l1 c9 T9 O# ?5 V; g
3. Draw radial lines from the center of the cam, corresponding to the cam angles identified on the displacement diagram.
* Y I* U5 h5 K; \! d `5 L' n4. The follower will be rotated in a direction opposite to the actual cam rotation.
9 [4 z& p3 l3 u; K: ^8 N( ?7 H5. Transfer the displacements from the displacement diagram to the radial lines.
- |. H7 {6 \: Z6. Measure the displacements from the base circle.
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$ I: J5 |1 [8 E: n2 e$ L B1.画出制定半径的基圆。
0 N# e4 T1 y/ p- _- G2.画出初始位置的从动件。
% g9 ]8 g) \ A3.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。
6 f$ z3 v4 r3 X5 C6 @ n* ]4.从动件与凸轮真实运动方向相反。; \( i0 O) e0 F7 P
5.将位移移到径向线上。
8 O9 g: D' z H; w8 i0 Y3 q7 @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' v- E9 o. O( Z7 ~- ~- {% ~
, r% F# [- W F& Y, H$ C6 W3 E3 r+ {1. Draw the base circle of radius.- L; U- d" |8 |
2. Draw the follower centerline in the home position.
- g c( P& P- c* P- J3. Draw the prime circle.
) O9 n1 y, U7 ~: u4. Draw the follower in the home position of radius.: ?# o" X! n6 ?; B& x; k
5. Draw an offset circle of radius, which will be tangent to the follower centerline.. p2 f. b; |( s$ E9 r
6. Draw lines tangent to the offset circle, corresponding to the reference cam angles on the displacement diagram.
/ m: u2 k2 X& V/ Y: p7. The follower will be rotated in a direction opposite to the actual cam rotation.
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$ Z u/ n2 {3 Q. m) A4 ?$ ]( [1.画出制定半径的基圆。9 @( \( N& B# V6 ~/ ?4 c
2.画出初始位置的从动件中心线。& Z# @7 u, C% W" V! O
3.画出理论廓线。
% V" r4 M0 n! d i4.画出初始位置的从动件。! ?( [1 V5 A2 I3 B3 H( e
5.以偏心距为半径画圆,与从动件中心线相切。! s! O0 X; F" M' O: u. m
6.与偏距圆相切画线,角度与位移图上横轴凸轮角度相对应。
& |$ y$ W+ |, l" c+ `1 U. U0 J7.从动件与凸轮真实运动方向相反。( }- X) ?2 l: R- n: P& p0 O
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