【20160406】Kinematic inversion
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The cam will be imagined as being stationary.6 z9 N: E/ f# Q* S& P2 S% k* j
The follower then should be rotated opposite to the direction of cam rotation.
* _6 }. `3 Z% j/ `6 S: C {, mThe desired location for the follower, at several positions, is constructed from the base circle.
# f% U3 w! q! ~& ` @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。$ n4 }' D0 m7 p r2 \
3 m2 @0 T8 E. n. TTo creating the cam shape: wrapping the displacement diagram around the base circle.& h, H) c( Z# v0 L
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。3 n2 L1 }2 D" l* z
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) f6 P/ C5 C0 a" I; c具体例子:- F8 [) U# \/ `2 ^, z9 ^1 l
① In-Line Knife-Edge Follower 对心直动尖顶从动件凸轮
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4 J S( ]" d+ j8 v8 o1. Draw the base circle of radius.5 [+ o( s% ]0 S0 \1 h
2. Draw the follower in the home position.) ~" O$ n" a) M; ^
3. Draw radial lines from the center of the cam, corresponding to the cam angles identified on the displacement diagram." }3 e* O% D+ P# i- D( z
4. The follower will be rotated in a direction opposite to the actual cam rotation.2 Q6 V3 [7 ?) a- n. N9 y
5. Transfer the displacements from the displacement diagram to the radial lines.
4 D( s3 [. P2 `( d+ w6. Measure the displacements from the base circle.1 J7 S6 D2 s( ?6 D9 Q6 K
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1.画出制定半径的基圆。
3 s. F* f" r! ]$ X! X+ P2.画出初始位置的从动件。( S1 y, T6 b( E- a
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。1 x' a5 o8 _+ |$ O. d* c
4.从动件与凸轮真实运动方向相反。5 c5 |( K" m" X: m* R
5.将位移移到径向线上。
( h, V0 v) d8 ^: X- e- q, g6.测量从动件远离凸轮基圆的距离。1 J' }; E4 S: z( |. x7 C
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② Offset Roller Follower 偏置滚轮从动件
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* d, H t0 w1 ~% U7 K! y I3 h6 u( c1. Draw the base circle of radius.+ P) s5 _$ _2 c, ~
2. Draw the follower centerline in the home position.& c9 r e2 E* _4 D" ?
3. Draw the prime circle.
# N9 j3 ?" d9 L1 p5 }+ b4. Draw the follower in the home position of radius.
# ^1 Z. S$ W7 h9 [; P9 a5. Draw an offset circle of radius, which will be tangent to the follower centerline.! h' C0 G/ J4 n- F
6. Draw lines tangent to the offset circle, corresponding to the reference cam angles on the displacement diagram.
7 F3 Y @* G# E" |7. The follower will be rotated in a direction opposite to the actual cam rotation.
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1.画出制定半径的基圆。+ V) F8 A5 W% w; C9 [
2.画出初始位置的从动件中心线。
, D. J+ V) ?+ Q' k3.画出理论廓线。
) J2 v3 [- J, o4.画出初始位置的从动件。8 z( y% h) X, A# D: R; ]$ e
5.以偏心距为半径画圆,与从动件中心线相切。( G+ r4 V5 b' b8 X
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。
: L6 ?. Y: x9 t+ {7.从动件与凸轮真实运动方向相反。* ~* U% i b! R4 G2 }* F
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