key, spline and pin joints

1、12 鍵、花鍵和銷聯(lián)接Key, spline and pin joints12-1 鍵聯(lián)接 Key joints12-2 花鍵聯(lián)接 Spline joints12-3 銷聯(lián)接 Pin joints12-4 其它聯(lián)接 Other joints 12-1 鍵聯(lián)接 Key joints 分類 Types of the key joints平鍵聯(lián)接的尺寸選擇和強度計算Option of sizes and strength calculations for straight key joints* Selection of sizes and strength & Calculations for s

2、traight key joints一、分類 Types of the key jointsKey jointsLoose jointsTight jointsStraight key jointsWoodruff key jointsOrdinary straight key jointsGuiding and sliding straight key jointsTaper keyTaper key jointsTangent double-taper key joints1. 普通平鍵聯(lián)接Ordinary straight key joints平鍵的兩側(cè)面是工作面，靠鍵和鍵槽之間的互壓傳

3、遞轉(zhuǎn)矩。The load is carried by the sides of straight keys. The both side surfaces of key and keyway press each other, through which the torque is transmitted.Rounded end Square endOne rounded and one square end2. 導向平鍵和滑鍵Guiding and sliding straight key3. 半圓鍵 Woodruff key4. 楔鍵聯(lián)接 Taper key joint楔鍵聯(lián)接上下面為工作

4、面，靠鍵、軸和轂之間的摩擦力以及鍵受到的偏壓傳遞扭矩。Torque is transmitted by friction of above and below surfaces on the key, shaft and hub.5. 切向鍵聯(lián)接 Tangent double-taper key joint 切向鍵的工作面是兩個楔鍵組成矩形的窄面，工作面上的擠壓力沿軸的切線方向，靠擠壓傳遞扭矩。Tangent double-taper key joint comprises two taper keys. The tow taper keys compose a rectangle and t

5、he small face of the rectangle is its operating surface. Torque is transmitted by the pressure between the operating surfaces of the key , shaft and hub. 失效形式Types of failure主要失效形式 The main types of failure：工作面壓潰Crushing（靜聯(lián)接 Fixed joints）工作面磨損 Wear（動聯(lián)接 Sliding joints）二、平鍵聯(lián)接的尺寸選擇和強度計算Selection of siz

6、es and strength calculations for straight key jointsv有時：鍵剪斷shear failure of the key（一般不作計算，重要時驗算 No such strength calculations are required in designing.） 工作面的壓潰或磨損發(fā)生在鍵、軸和轂三者中較弱的零件上，一般為轂。Crushing or wear of the operating surfaces usually take place on the elements of which the strength is weakest am

7、ong the key, shaft and hub. And it usually occurs on the hub.2. 計算公式 Calculations假設(shè)壓力在鍵的接觸長度范圍內(nèi)分布均勻，則根據(jù)擠壓強度或耐磨性的條件性計算It is assumed that the pressure is uniformly distributed over the surfaces of contact between the sides of the key and the hub and the shaft. Then the strength conditions to resist cr

8、ushing and wear respectively are：Allowable pressing stressAllowable pressureContact length of keyHeight of keyContact height of key and hub3. 平鍵聯(lián)接的計算步驟 Design procedure for straight key joints 花鍵聯(lián)接的特點 Features of spline joints 花鍵聯(lián)接的分類 Types of spline joints 12-2 花鍵聯(lián)接 Spline joints依靠軸和轂上齒的互壓傳遞轉(zhuǎn)矩，可用于動

9、聯(lián)接和靜聯(lián)接。The teeth of shaft and hub press each other, through which the torque is transmitted. The spline joints can be used for both fixed and sliding joints. 一、花鍵聯(lián)接的特點 Features of spline jointsWith respect to straight key joints:Uniform force distributionLess stress concentrationMore accurately cent

10、eredTeeth are difficult to be manufactured二、花鍵聯(lián)接的分類 Types of spline joints（矩形花鍵 Rectangle spline、漸開線花鍵Involute spline 、三角形花鍵Triangle spline ）三、花鍵的定心方式Centering methods of spline 矩形花鍵定心方式Major diameter fit Minor diameter fit Fit on sides of spline漸開線花鍵定心方式Major diameter fit Side fit12-3 銷聯(lián)接 Pin joint

11、s 銷聯(lián)接的功用 Functions of pin joints 銷的分類 Types of pin joints（1）定位 Locating （2）安全裝置 Safety device （3）傳遞不大的載荷 Transmit relatively small loads一、銷聯(lián)接的功用 Functions of pin joints二、銷的分類 Types of pin（1）普通圓柱銷 Plain cylindrical pins （多次裝拆，定位精度下降 Locating precision is lowered after disassembled many times） （2）普通圓錐

12、銷 Plain taper pins （錐度1：50 、自鎖、可以多次裝拆 With a taper of 1:50,selflocking, may be disassembled for many times ）v（3）特殊形式銷 Special types of pin v 孔未開通或拆卸困難時： 螺尾錐銷 With thread for disassemblyv 沖擊、振動或變載荷時： 開尾錐銷、槽銷或彈性圓柱銷（防松） With open slot for fastening 12-4 其它聯(lián)接 Other joints 成形聯(lián)接 Shaped joints 過盈聯(lián)接Interference fit joints 焊接 Welded joints一、成形聯(lián)接 Shaped join