圆柱齿轮公差与检测.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,目的：了解圆柱齿轮的公差标准 Aim:To understand tolerance standards of Cylindrical gear 初步掌握： Grasp preliminarily: 1.应用要求、加工误差 Application requirements and manufacturing error 2.评定指标 Evaluation index 3.图样标注 Labels of pattern 4.齿轮精度设计 Design of gear accuracy 操作技能：评定指标的检验 Manipulative skill:The test of evaluation index.,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,作用：传递空间任意两轴（平行、相交、交错）的旋转运动，或将转动转换为移动。Founction:To transmit the revolving movements of any two axles(parallel,intersectant and interlaced) in space.And to convert turn to shift.,缺点：要求较高的制造和安装精度，加工成本高、不适宜远距离传动。 Disadvantages:It needs higher accuracies of manufacture and installment. Conversion cost is high and it is not suitable for long distance transmission.,齿轮传动的类型 Types of gear drive,传动齿轮：转速较高，功率较大 （汽车 飞机等变速装置） Drive gear:Higher rotation rate and power(Speed variators in automobiles and airplanes) 动力齿轮：转速不高，传递扭矩（矿山机械 起重机械） Power gear:The speed of revolution is not high and it transmits torque(mining machine and hoisting machinery) 分度齿轮：精确回转（精密机床 仪表中的分度装置） Dividing gear:Precise rotation(precision machine tool and dividing device in instrumentation),齿轮传动机构组成 The form of gear transimission mechanism,齿轮副、轴、轴承、箱体pair of gears, axles, bearings and boxes,失效形式 failure mode,轮齿折断 tooth breakage,1.由于多次重复的弯曲应力和应力集中造成的疲劳折断；The fatigue fracture which is caused by oft-repeated bending stresses and stress concentration. 2.由于突然严重过载或冲击载荷作用引起的过载折断。The overload break which is caused by sudden severe overload or impact load. 直齿轮：齿宽较小的往往发生全齿折断,齿宽较大的直齿轮或斜齿轮则容易发生局部折断。 Straight gear:The gears with smaller breadth of tooth often emerge whole tooth fracture while the straight gears or helical gears with bigger breadth of tooth are easy to emerge local break.,一、 轮齿的失效形式,失效形式,齿面点蚀 Tooth surface pitting,原因：由于在齿面啮合处脉动循环变接触应力长期作用下，当应力峰值超过材料的接触疲劳极限，经过一定应力循环次数后，先在节线附近的齿廓表面产生细微的疲劳裂纹。随着裂纹的扩展，将导致小块金属剥落，产生齿面点蚀。Reason:Because of the long term effect of pulsating cyclic variable contact stress on meshing point of tooth surface.When peak stress exceeds materials contact fatigue limit, hairlike fatigue cracks will appear on tooth profile surface around nodel line after certain number of times of stress cycle.With the extending of flaws. Scrap metal will peel off to produce tooth surface pitting. 点蚀不良影响：影响轮齿正常啮合，引起冲击和噪声，造成传动的不平稳。 Harmful effects of pitting:Influencing the normal engagement of gear teeth,causing concussions and noise,creating un-stationary transmission.,一、 轮齿的失效形式,失效形式,齿面胶合 Tooth surface bonding,高速重载传动中，常因啮合区温度升高而引起润滑失效，致使齿面金属直接接触而相互粘连。当齿面相对滑动时，较软的齿面沿滑动方向被撕下而形成沟纹。On high speed and heavy load transmission.The raise of meshing zones temperature usually causes lubrication losing efficacy to lead to the direct contacts of tooth surface metal and adhesions of each other.When tooth surfaces slither relatively, softer tooth surfaces are torn-out on glide direction to form grooves.,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.,1-1.齿轮的应用要求 Application requirements of gears,7.1 应用要求及加工误差 Application requirements and processing errors,传递运动的准确性 The accuracy of transfer motion 传递运动的平稳性 The stability of transfer motion 载荷分布的均匀性 The homogeneity of load distribution,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 wheels movement.We are supposed to restrict the uneven movements of gears in one round.,1.传递运动的准确性 The accuracy of transfer motions.,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 pitchconcussion, shake and noise.,2.传动的平稳性 The stability of transfer motion,3.载荷分布的均匀性 The homogeneity of load distribution,轮齿啮合过程中，工作齿面沿全齿高和全齿长上保持均匀接触，并且接触面积尽可能的大。In the engagement process of gear teeth.Working flanks of teeth are kept in even contact on whole teeth height and whole teeth length and contact areas should be as bigger as possible.,引起应力集中，造成局部磨损，轮齿折断，影响齿轮的使用寿命 Causing stress concentration to lead to concentrated wear and tooth breakage so that influencing working lifes of gears.,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.,4.齿轮副侧隙的合理性 Rationalities of backlashes of gear pairs,1.贮存润滑油 store up lubricating oil 2.补偿齿轮的变形 compensate the distortions of gears 3.制造和安装误差所引起的尺寸变动 size changes which are caused by Manufacturing and installation errors,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 principlesform cutting method 展成法 generating method,7.2 加工误差的来源与分类 The origins and classifications of mismachining tolerance,滚齿机 hobbing machine,误差来源 Sources of errors,工艺系统：机床、夹具、刀具、齿坯本身 Process system:machine tool, fixture, cutter and gear blanks themselves.,安装、调整 Install and adjust,1 几何偏心 ej Geometric eccentricity,1 齿轮加工误差来源 The sources of errors in gear machining,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,1分度蜗轮dividing worm wheel 2 蜗杆worm 3 滚刀hobbing cutter 4 齿坯gear blanks,Gears with eccentric motions,3 机床传动链的高频误差 High frequency errors of Machine tool transmission chains,原因：分度蜗杆的安装偏心和轴向蹿动,导致蜗轮（齿坯）转速不均匀 Reasons:The installation eccentricities and axial drifting of indexing worms contribute to inhomogeneous speeds of worm gears(gear blanks). 结果：加工出的齿轮有齿距偏差和齿形偏差 Results:Processed gears have pitch deviations and profile deviations.,4滚刀的安装误差和加工误差Installation errors and mismachining tolerances of hobbing cutters,滚刀偏心 ed Eccentricity of hobbing cutter,2.齿轮加工误差的分类The classifications of gear machining errors, 按表现特征可分为4类：It could be divided into four classes acording to performance characteristic,齿廓误差 齿距误差 Tooth profile error Pitch error 齿向误差 齿厚偏差 Tooth alignment error Tooth thickness deviation,齿廓相对于工件的旋转中心分布不均匀 Tooth profile is irregularly distributed to rotating center of the workpiece.,齿廓不是理论的渐开线 Tooth profile is not theoretical involute.,齿面沿齿轮轴线方向的形状和位置误差 Tooth flanks form and position errors along gear axis.,齿厚相对于理论值在整个齿圈上不一致 Tooth thicknesss inconformity to theoretical value on whole gear ring., 按方向特征可分为3类 It could be divided into three classes according to directional features.,径向误差 切向误差 轴向误差 Radial errors Tangential errors Axial errors,齿高方向 齿厚方向 齿向方向 Tooth height direction Tooth thickness direction Direction of tooth, , 按周期或频率特征可分 According to cycle or frequency characteristic,it could divided into,长周期误差 Long cycle error,短周期误差 Short cycle error,传递运动的准确性 The accuracy of transfer motion,工作平稳性 Work stability,以齿轮一转为周期 Regard gears one turn as cycle,以齿轮一齿为周期 Regard gears one tooth as cycle,圆柱齿轮传动公差 Transmission tolerances of cylindrical gears,GB/T10095.1-2001GB/T10095.2-2001,传递运动准确性的评定指标 The evaluation indexes of transfer motion accuracy 传递运动平稳性的评定指标 The evaluation indexes of transfer motion stability 载荷分布均匀性的评定指标 The evaluation indexes of load distribution homogeneity 影响侧隙的单个齿轮因素 Single gear factor which influences sideshake,7.3 单个齿轮的评定指标 The evaluation criteria of single gear,-1 传递运动准确性的检测项目The inspection items of transfer motion accuracy,切向综合总偏差（F i） Tangential general deviation 齿距累积总偏差（Fp） Cumulative pitch error 径向跳动（Fr） Radial runout 径向综合总偏差（Fi） Radical general deviation 公法线长度变动（Fw）The changes of base tangent length,单项评定指标 Single evaluation index,齿轮一转范围内，测头在齿槽内与齿高中部双面接触，测头相对于齿轮轴线的最大变动量称齿圈径向跳动。Within gears one turn range, gauge head is contacted in double sides with tooth height middle part within tooth space.The maximum variation that gauge contains toward gear axis is called gear ring radical runout.,Fr主要反映由于齿坯偏心引起的齿轮径向长周期误差。Fr mainly reflects the gear radical long term error which is caused by the eccentricity of gear blanks 可用齿圈径向跳动检查仪测量，测头可以用球形或锥形。 It could tested by gear ring radical runout detector. Gauge head could use sphere or taper.,-2 传动工作平稳性的检测项目 The inspection items of driving work stability,一齿切向综合偏差 f i Tooth tangential and general deviation 一齿径向综合偏差 f i Tooth radical and general deviation 齿廓偏差 Tooth profile deviation 基圆齿距偏差 fpb Base circle pitch deviation 单个齿距偏差 fpt Single pitch deviation,-3 载荷分布均匀性的检测项目 The inspection items of load distributions homogeneity,螺旋线偏差：在端面基圆切线方向上测得的实际螺旋线偏离设计螺旋线的量 Helix deviation:The tested amount that actual helix deviates from designed helix on the tangential direction of end face base circle. （1） 螺旋线总偏差F 在计值范围内，包容实际螺旋线迹线的两条设计螺旋线迹线间的距离Helix total deviation F Within the range of values,the distances between two designed helix path lines which include helix path lines. （2） 螺旋线形状偏差 ff 在计值范围内，包容实际螺旋线迹线的两条与平均螺旋线迹线完全相同曲线间的距离 Helix shape deviation ff Within the range of values,the distances between two curves which are same as average helix path lines and including actual helix path lines. （3） 螺旋线倾斜偏差fh 在计值范围的两端与平均螺旋迹线相交的设计螺旋线迹线间的距离 Helix incline deviation fh Within the range of values,the distances between designed helix path lines that both ends are intersectant with average helix path lines.,-4 影响侧隙的单个齿轮因素 Single gear factors that influence sideshakes,1 齿厚偏差fSnTooth thickness deviation齿厚的上偏差（ESnS）The upper deviation of tooth thickness 下偏差（ESni）Lower deviation,一般都为负值 Commonly to be negative value,2 公法线长度偏差 Base tangent length deviation,7.4 齿轮副评定指标 The evaluation indexes of gear pairs,1 轴线的平行度误差 The parallelism errors of axes 2 中心距偏差 The deviations of centre-to-centre separations 3 接触斑点 Contact spot 4 齿轮副的侧隙 The sideshake of gear pair,4 齿轮副侧隙 The sideshake of gear pair,齿轮副的最小极限侧隙应根据齿轮工作时的温度和润滑条件确定，与齿轮的精度等级无关。The minimum limit sideshake of gear pair should be ascertained by gears working temperature and lubrication condition.It has nothing to do with the gears accuracy class.,高温工作的传动齿轮，为保证正常润滑，避免发热卡死，要求有较大的侧隙；There should be biggish sideshake for drive gear working in high terperature.That is to ensure normal lubrication and preventing the gear from fever and jammed 而需正反转或读数机构的齿轮，为避免空程，则要求较小的侧隙。There should be lesser sideshake for the gears to prevent idle stroke which need positive inversion or reading mechanism., 侧隙获得方法 The methods to obtain sideshake,1.基齿厚制:即固定齿厚的极限偏差，通过改变中心距的基本偏差来获得不同的最小极限侧隙，此方法用于中心距可调的机构。Base gear thickness:Fix gear thicknesss limit deviations.Obtaining different minimum limit side gaps through changing the basic deviations of centre-to-centre separations. This method is used for the mechanisms of which centre-to-centre separations are tunable. 2.基中心距制:即固定中心距的极限偏差，通过改变齿厚的上下偏差来得到不同的最小极限侧隙，国标采用后一种. Base centre-to-centre separation distance system:Fix centre-to-centre separations limit deviation.Obtaining different minimum limit side gaps through changing the upper and lower deviations of gear thickness. Chinese Standard adopts the latter.,jbnmin,jbnmin = jbn1 + jbn2,工作温度 润滑方式 圆周速度 Working temperature Lubrication method Peripheral speed,补偿温升引起的变形Compensate the distortions caused by temperature rise,保证齿轮工作面的正常润滑 Ensure the normal lubrication on gears working surface,最小法向极限侧隙 The minimum limit sideshake on normal,Jbn2取决于润滑方式和齿轮工作的圆周速度Jbn2 lies on lubricating method and the working peripheral speed of gear,7.5 渐开线圆柱齿轮精度设计 The precision design of involute cylindrical gear,齿轮精度等级的确定 The ascertainment of gears accuracy class 齿轮副侧隙、齿厚极限偏差的确定 The ascertainment of backlash of gear pair and limit deviation of tooth thickness 齿坯精度和齿轮表面粗糙度 Precision of gear blanks and roughness of gear surfaces 图样标注 Pattern annotation,GB/T 10095.1-2001 渐开线圆柱齿轮精度第1部分 轮齿同侧齿面偏差的定义和允许值The accuracy of involute cylindrical gear Part1 The definitions and allowable values of tooth flank tooth surface deviations GB/T 10095.2-2001 渐开线圆柱齿轮 精度第2部分 径向综合偏差与径向跳动的定义和允许值The accuracy of involute cylindrical gear Part2 The definitions and allowable values of radial integrated deviations and radial runout GB/Z 18620.14 指导性技术文件 Technical guidance document,分度圆直径：510000mm standard pitch diameter 法向模数：0.570mm normal modulus 齿宽：41000mm tooth width,标准适用范围 The scope of applications for standards,13个精度等级 Thirteen accuracy classes 0 、1 、2 3 5 6 8 9 12,待用inactive,高精度等级 High accuracy classes,中等精度等级 Middle accuracy classes,最低精度等级The lowest accuracy classes,7 GB/T10095.2（1）2001,一、渐开线圆柱齿轮精度等级 The accuracy classes for involute cylindrical gears,1.齿轮精度等级的选择 The selection for gear precision grade,根据用途、使用要求、传递功率、圆周速度及其它技术要求而定，同时考虑切齿工艺及经济性。According to applications, operating requirements, transmitted power, peripheral speed and other technical requirements thus thinking about cutting process and economy.,选择原则 Selection principles,选择方法 Selection methods,1）计算法 computation technique 依据齿轮传动用途的主要要求，计算确定出其中一种使用要求的精度等级，再按其他方面要求，作适当协调，来确定其它使用要求的精度等级.According to the main requirements of gear drive applications,calculating and ascertaining one usage requirements accuracy class.Then according to other requirements of other aspects and making proper coordination to ascertain the accuracy classes of other usage requirements.,当对传递运动准确性没有特别要求时，第公差组的精度常比第公差组低一个等级。When there are no special requirements for the accuracy of transfer motion.The precision accuracy of No.1 Tolerance group is usually lower by one class to No.2 Tolerance group 当所传递的功率不特别大时，第公差组一般采用和第公差组相同的精度等级。When the transmission power is not very high. No.3 Tolerance group usually adopts the same accuracy classes as No.2 Tolerance group. 齿轮副中两齿轮对应公差组的精度采用同级，也允许不同级。The corresponding tolerance groups that are of two gears in gear pairs also adopt different classes.,齿轮圆周线速度第公差组的精度等级 Gears circumferential line velocity The accuracy classes of No.2 Tolerance group,No.1 Tolerance group,No.2 Tolerance group,No.3 Tolerance group,The accuracies of transfer motions,The stabilities of transmissions,The homogeneities of load distributions,2）类比法 The methods of analogue 依据以往产品设计、性能试验以及使用过程中所积累的经验、可靠的技术资料，经过与所设计的齿轮在用途、工作条件及技术性能上作对比后，选定其精度等级。According to the accumulated experiences and reliable technical data from past products design, performance test and use procedure.Choosing the accuracy classes after comparing with the designed gears on applications, working conditions and technical functions.,各种机械采用齿轮的精度等级 The adoptted gears accuracy classes for different machines,2.齿轮精度等级标注 The label for gears accuracy class,-0.330 -0.495,（ ）GB/T10095.22001,例：7-6-6 G M GB/T10095.22001,7 F L GB/T10095.22001,表示齿轮第、公差组的精度分别为7级、6级、6级。The precision accuracy of the tolerance groups , and for gears are respectively as class7,6 and 6.,齿厚上、下偏差代号分别为、。Gears upper and lower deviation codes are respectively as and .,二.齿厚极限偏差代号 The code for limit deviation of tooth thickness,齿厚极限偏差的数值=齿距极限偏差（fpt）的倍数 The numerical value of limit deviation of tooth thickness =The multiple of transverse pitch limit deviation,国标规定:14种齿厚极限偏差的数值，大写的英文字母表示。National standard:14 kinds of numerical values for limit deviation of tooth thickness and indicated by capital letters in English.,三.齿轮坯的精度和齿轮面粗糙度 Precision of gear blanks and Roughness of gear surface,齿坯公差 Tooth blank tolerance,齿坯基准面径向和端面跳动公差 Radial and end face run out tolerances for gear blanks basic face,齿轮表面粗糙度 Roughness of gear surface,齿面的表面粗糙度对齿轮的传动精度(噪声和振动)、表面承载能力(点蚀、胶合和磨损)和弯曲强度(齿根过渡曲面状况)等都会产生很大的影响。 Gears surface roughness would exert big effects on gears transmission accuracy(Noise and vibration), surface carrying capacity(corrosive pitting, glue together and wear and tear)and bending strength(Fillet surface condition).,单位：m,四、图样标注例 The examples for pattern annotation,