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1、滁州学院12级机械本一班主讲:胡恩生编辑:金冉贾富文资料搜集:胡恩生蒋杉杉14·3·25GearsDefinition of Gears:A gear is a rotating machinepart having cutteeth, orcogs,whichmeshwith another toothed part in order to transmit torque. Two or mors gears working in tandem are called atransmissionand can produce a mec
2、hanical 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-rotat
3、ing 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。Gears are direct-
4、contact bodies,operating in pairs, that transmit motionand force from one rotating shafttoanother, or from a shaft to a slide (滑动部件)(rack),by means of successively engagingProjections(突出物)called teeth.Therearefourmaintypesofgears:spur,helical,worm,andbevel。spurandhelical
5、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
6、 with a gear of adifferent type .To prevent jamming as a result of thermal expansion ,to aid lubrication and to compensate for unavoidable inaccuracies in manufacture ,all powertransmitting gears must have backlash .this meansthat on pitch circles of a mating pair ,the s
7、pace width on the pinion must be slinghtly greather than the tooth thickness on the gear,and vice versa(反之亦然)。On instrument gears , backlash can be eliminathed by using a gear split down the middle ,one half being ratable to the other .A,spring forces the split gear teet
8、h to occupy the full width of the pinion space .Helical gears have certainadvantages,for example , when