机械英语ppt.ppt

Gears Definition?of?Gears: A?gear?is?a?rotating?machine part?having?cut?teeth,?or?cogs,which? mesh?with?another?toothed?part?in?order?to?transmit?torque.?Two?or?mors?gears?working?in?tandem?are?called?a?transmission?and?can?produce?a?mechanical?advantage?through?a?gear?ratio?and?thus?may?be?considered?a?simple?machine.?Geared?devices?can?change?the?speed,?magnitude,?and?direction?of?a?power?source.?The?most?common?situation?is?for?a?gear?to?mesh?withanother?gear,?however?a?gear?can?also?mesh?a?non- rotating?toothed?part,called?a?rack,? thereby?producing?translation?instead?of?rotation.? 我的翻译：齿轮是一个旋转的机械零件，有削减的齿，它与另一个齿的一部分，以便传输扭矩。两个或多个齿轮同步工作被称为传动系统，并且能够产生通过机械传动比的优势，因此可以被认为是简单的机械。减速装置可以改变的速度，规模，以及一个电源方向。最常见的情况是谦卑地与另一个齿轮，齿轮，齿轮也不过一目了非旋转式齿形的一部分，称为机架，从而产生传动，而不是旋转。 ? spur and helical gears直齿轮和斜齿轮 ? A?gear?having?tooth?elements?that?are?straight?and?parallel?to?its?axis?is?knowns?as?a?spur?gear?.?A?spur?pair?can?be?used?to?connect?parallel?shafts?only?.?Parallel?shafts?,however?,can?also?be?connected?by?gears?of?another?type?,and?a?spur?gear?can?be?mated?with?a?gear?of?adifferent?type?.? Worm and Bevel Gears蜗轮和锥齿轮传动 Words and Expressions Helical gear Spur gear Backlash Pinion Herringbone Coefficient of friction Truncated cone Spiral Hypoid gear conjugate 斜齿轮，螺旋齿轮 正齿轮 齿间隙 小齿轮 人字形，交叉缝式 摩擦系数 截头圆锥体 螺旋形的：螺线 偏轴伞齿轮 成对的，共轭的 Summary总结 In?the?force?analysis?of?spur?gears,?the?forces?are?assumed?to?act?in?a?single?plane.?In?this?lesson?we?shall?study?gears?in?which?the?forces?have?three?dimensions.?在直齿圆柱齿轮的受力分析中，假定各力作用在单一平面的．在这一课中，我们将研究承受三维作用力的齿轮． The?reason?for?this,?in?the?case?of?helical?gears,?is?that?the?teeth?are?not?parallel?to?the?axis?of?rotation.?就斜齿轮而言，是因为其轮齿是与其回转轴线不平行而产生的。 And?in?the?case?of?bevel?gears,?the?rotational?axes?are?not?parallel?to?each?other.?而就锥齿轮而言，是因为各回转轴线互相不干行。 There?are?also?other?reasons,?as?we?shall?learn.?当然像我们将。要讨论的那样，还有其他的原因 ?Helical?gears?are?used?to?transmit?motion?between?parallel?shafts.?斜齿轮用于传递平行轴之间的运动。 The?helix?angle?is?the?sa