【菜鸟成长记】20岁后，我在机械的每一天

apmc111

加油，贵在坚持，希望你五年后还能来一篇总结

黑森林的鹿

apmc111 发表于 2016-3-28 21:05
; t. G- O4 Z" Q7 Y! l2 i/ T加油，贵在坚持，希望你五年后还能来一篇总结

) j/ s  Z& B7 b( v: e7 s  q7 z" M4 p恩恩，会一直坚持下去的！感谢关注！

swj1234

可以
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黑森林的鹿

【20160329】VelocityAnalysis

. U% c9 w6 }( A; [& v; \Velocity analysis : determination of velocity in a linkage.
速度分析：决定构件速度的分析。

( W- `, F  ?" yTwo common analysis methods：
Relative velocity method
Instantaneous center method
9 R$ U) N6 g% j" P; [2 H" t- z两种常用方法：相对速度法和速度瞬心法。
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Relative velocity: the velocity of one object is related to that of another reference object, which can also be moving.
相对速度：两个均运动的杆件之间相对的运动速度。

/ x" j. a( m! Z# F9 D2 f1 cVA = absolute velocity of point A
VB/A= relative velocity of pointBwith respect to A
$ p* j2 O9 k# Y  ~相对速度的一些记法。
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Instant center: a instantaneous pivot point about which the particular link instantaneously appears to be in pure rotation.
% }8 T8 z4 S4 ?3 Y* f2 c速度瞬心：在运动的瞬时可看做是旋转中心的点。
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黑森林的鹿

【20160330】Acceleration Analysis
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Tangential acceleration 切向加速度

# i  B- d8 r5 u  E4 `- b+ `) w' H$ iNormal acceleration 法向加速度
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" O* D: m* R" z$ T' s4 i$ n* TTotal acceleration 和加速度

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Relative motion: the difference between the motion of two points.
相对运动：两点运动的差（矢量）。
' I& t9 f  h$ k5 [6 e  d1 t3 yRelative acceleration: the acceleration of one object as observed from another reference object that is also moving.
- R, Z8 Z1 m8 q, q相对加速度：一点相对于运动的另一点的加速度。
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, L. F1 h) N+ g& B( GCoriolis Acceleration 科氏加速度

The magnitude of the Coriolis component:

Both the relative linear velocity and the absolute angular velocity can be determined from a thorough velocity analysis.
计算科氏加速度的量可以从运动学分析中得到。

黑森林的鹿

【20160331】Cams: Design and Kinematic Analysis


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The camshaft is driven by the engine.
As the cam rotates, a rocker arm drags on its oblong surface.
The rocker arm imparts a linear, reciprocating motion to a valve stem.
( b8 b2 o/ N; c  |( s  ?$ O: OThe spring is used around the valve stem. The rocker arm follower needs to maintain contact with the cam surface to achieve the desired motion.
4 ^8 R2 r) w7 V4 u2 ^发动机中控制阀门进排气的凸轮。应用弹簧使杆件与凸轮保持接触。

The unique feature of a cam
Cams can be used to obtain unusual or irregular motion that would be difficult or impossible, to obtain from other linkages, because the motion of cams can be prescribed.
! B1 M2 A9 I0 w6 [1 r# e: R凸轮的特点：凸轮可实现一般杆件不能或难于实现的功能。

however1241

又来看楼主了，楼主还在更新着。

黑森林的鹿

【20160401】Type of Cams
" p- z8 g- j4 f/ D( ~凸轮分类
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; W% c3 q5 N3 Z8 n. ^6 ^* ?Plate or disk cams
  W4 L! F( l2 MThis type of cam is formed on a disk or plate.
; y9 S# N- N" I* x; @: RThe radial distance from the center of the disk is varied.
平面凸轮：在平面内形成的凸轮，与中心的径向距离是变化的。
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  x8 \9 V" J7 ~; TCylindrical or drum cams
1 n4 p1 S! K5 B5 WA groove is cut into the cylinder, with a varying location along the axis of rotation.
The follower is attached to the groove, thus giving the follower motion along the axis of rotation.
4 U% @8 p& J" {7 ~& s8 a; u圆柱凸轮：柱体上刻有凹槽，沿轴向变化分布，从动件被限制在凹槽内，因此沿轴向运动。
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Linear cam
6 P- V9 l9 ]+ A1 ?& B# P, eA groove is cut into the block with a distance that varies from the plane of translation.
% P4 {9 K" K; YAttaching a follower in the groove gives the follower motion perpendicular to the plane of translation.
线凸轮：在板内刻有线型凹槽，从动件运动垂直于板的传动方向。

however1241

however1241 发表于 2016-4-1 18:18
  X) z& T' m6 |/ @! a# \又来看楼主了，楼主还在更新着。

' q# a0 U, ^6 O) J; n) ]$ |老鹰版主会鼓励吧。
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刘星宇

同大二，啥专业基础课都没学，就搞机械创新，深深体会到无知，学起更有动力、更有兴趣，还有，不带手机去上课，就成功了一半，共勉