7-圆柱齿轮公差与检测PPT.ppt

第7章 圆柱齿轮公差与配合应用Chapter 7 Cylindrical gears tolerance and fit application;基本要求 Basic requirements;特点 Traits 1 结构紧凑 Compact structure 2 恒定的传动比 Constant transmission ratio 3 传动效率高 High transmission efficiency 4 可实现平行轴、相交轴和交错轴之间的传动 It could realize the transmission between parallel axles, intersectant axles and interlaced axles 5 使用寿命长 Long working life 6 维护保养简单 Sample to maintain;齿轮传动的类型 Types of gear drive; ;一、 轮齿的失效形式; 传动精度 transmission accuracy 齿侧间隙---齿轮副合理性 backlash in circular tooth---The rationality of gear pairs. ;要求从动轮与主动轮运动协调，应限制齿轮一转内传动比的不均匀性。Requiring the coordination of driven wheel and action wheel’s movement.We are supposed to restrict the uneven movements of gears in one round. ;要求:齿轮在转过一个齿距角的范围内，其最大转角误差应限制在一定的范围内。 Requirement:The maximum angular error should be restricted in a certain range within the range of that gear turning around one angular pitch. 一个齿距角内瞬时传动比→冲击、振动和噪声 Instantaneous transmission ratio within one angular pitch→concussion, shake and noise. ;3.载荷分布的均匀性 The homogeneity of load distribution ; 齿轮传动过程中，非接触面之间一定要有合理的间隙。There must be reasonable clearance between non-contact surface in the process of gear transmission. ;不同齿轮的传动精度要求 Transmission accuracy requirements of different gears ;加工方法：rocessing methods: 按齿廓形成原理→ 仿形法 According to tooth profiles’ forming principles→form cutting method 展成法 generating method;滚齿机 hobbing machine ;误差来源 Sources of errors;齿坯 Gear blank;2 运动偏心ey → ek +分度蜗轮加工误差 Eccentric motion ey → ek +mismachining tolerances of dividing worm wheel ;Gears with eccentric motions ;3〉 机床传动链的高频误差 High frequency errors of Machine tool transmission chains;4〉滚刀的安装误差和加工误差Installation errors and mismachining tolerances of hobbing cutters;2.齿轮加工误差的分类The classifications of gear machining errors ;㈡ 按方向特征可分为3类 It could be divided into three classes according to directional features. ;㈢ 按周期或频率特征可分 According to cycle or frequency characteristic,it could divided into…;圆柱齿轮传动公差 Transmissio