【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
5 r# _; J. u+ O# J' E加油，贵在坚持，希望你五年后还能来一篇总结

- e8 Y" B+ u! u9 K. T7 D恩恩，会一直坚持下去的！感谢关注！
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swj1234

可以

黑森林的鹿

【20160329】VelocityAnalysis
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Velocity analysis : determination of velocity in a linkage.
& f) Z5 v; i- k4 E速度分析：决定构件速度的分析。
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" ]( `3 O, l  l, L+ B& n6 BTwo common analysis methods：
" E$ n3 ~, q5 w7 }: K$ I5 qRelative velocity method
Instantaneous center method
8 k3 w! g$ `) t两种常用方法：相对速度法和速度瞬心法。

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。

VA = absolute velocity of point A
VB/A= relative velocity of pointBwith respect to A
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.
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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( J2 f$ f8 p! g' [9 ETangential acceleration 切向加速度

Normal acceleration 法向加速度
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Total acceleration 和加速度
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+ G. W+ B0 L9 p0 IRelative motion: the difference between the motion of two points.
相对运动：两点运动的差（矢量）。
2 z! S& ~$ F. t2 D! ORelative acceleration: the acceleration of one object as observed from another reference object that is also moving.
相对加速度：一点相对于运动的另一点的加速度。

Coriolis 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。
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黑森林的鹿

【20160331】Cams: Design and Kinematic Analysis


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The camshaft is driven by the engine.
3 d2 `0 _7 {# Y0 L# wAs the cam rotates, a rocker arm drags on its oblong surface.
The rocker arm imparts a linear, reciprocating motion to a valve stem.
; V3 E7 K* N6 e. Z/ ^' d( ]$ RThe spring is used around the valve stem. The rocker arm follower needs to maintain contact with the cam surface to achieve the desired motion.
; t; |. o% z, j# ]" R) h& [% u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.
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
% `( T; L3 Y1 ~7 R8 _& ^凸轮分类
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Plate or disk cams
This type of cam is formed on a disk or plate.
The radial distance from the center of the disk is varied.
7 P+ B* O' l& y1 E% [. K6 ~" R3 J' |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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3 {3 p: E6 [2 }+ P( O+ UCylindrical or drum cams
A groove is cut into the cylinder, with a varying location along the axis of rotation.
2 L: @" L- e- g: l% @1 K+ tThe follower is attached to the groove, thus giving the follower motion along the axis of rotation.
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。

$ {1 K4 f  ~9 g2 ~4 d0 qLinear cam
! d7 A) u1 p. I6 m( ?( AA groove is cut into the block with a distance that varies from the plane of translation.
Attaching a follower in the groove gives the follower motion perpendicular to the plane of translation.
% T$ A) z( D: m: n1 W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。

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however1241

however1241 发表于 2016-4-1 18:18
又来看楼主了，楼主还在更新着。

! n2 C- K; _& u5 T! @, F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