ChainDriveNew 机械设计 英文PPT教案_重大_精品.ppt

* Very long center distances cause excessive tension and may cause the chain to jump teeth. Long chains may need to be supported by guides or idlers. Chain Drives(链传动) Terminology 1. Chains 链 2. Sprocket(Driving, Driven) 链轮 Chain transmits load in tension to and from sprocket. * Power transmission chains can be categorized as Roller chain Silent chain Engineering steel chain Detachable chain. 传动链 起重链 牵引链 齿形链 链 滚子链 * pins that pivot inside the roller bushings. pins are press fitted into the pin link plates roller bushings are press fitted into roller link plates free-turning roller encircles each bushing to provide rolling engagement and contact with sprocket teeth The distance between flexing joints in roller chain is the pitch(链节距), which is the basic designation for different chain sizes. Roller chain * 2.Joints (联接链节) Axial positioning methods： (Spring Pins)开口销， 多用于大节距链 (Spring U board)弹簧卡片， 多用于小节距链 　　设计时，链节数以取为偶数(Even)为宜，这样可避免使用过渡链节(Offset link bar)，因为过渡链节会使链的承载能力下降。 过渡链节 * 3.滚子链的规格 标记示例： 08A-1×86 GB1243.1–83 * Multi-Strands roller chain Double-pitch roller chain Because a given length of double-pitch chain contains only half as many pitches, it is lighter and less expensive than standard roller chain. Another choice for high power transmission Choice for long shaft distance transmission * Center guide chain Side guide chain Silent chain (无声链) * Where the transmission of high power is the primary requirement, engineering steel drive chains offer many useful solutions. Engineering steel chain(工程链) Standard types: heavy duty offset sidebar engineering steel roller chain heavy duty straight-sidebar roller-type conveyor chain 主要用于重型传送装置 * Advantages detachable links can be separated at any joint without using special tools Detachable chain is low in cost and can transmit up to 25 hp at speeds to 350 fpm. Detachable chain（可拆链） Detachable link chains are fabricated with one-piece elements and can be press-formed from flat rolled steel, 结构简单、可不用特殊工具安装、