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河南工业大学机电工程学院毕业设计说明书设计题目:轴承磨床自动定位装夹系统设计学生姓名：刘玉申学号：2004141021专业班级：机自0401指导教师：马玉平2008年05月30日河南工业大学1目次前言·····································································································11全自动轴承内圈内圆磨床概述·····························································21.1磨削的基本原理···························································································21.2全自动轴承内圈内圆磨床的加工对象、范围及要求········································32自动轴承内圈内圆磨床总体设计与布局·················································52.1机床的主要运动及参数分析··········································································52.2影响机床加工精度和效率的工艺因素····························································62.3机床主要部件结构方案评价··········································································72.4机床的工作循环过程·····················································································93.轴承内圈内圆夹具设计·····································································103.1自动定位夹具设计目的···············································································103.2工件的定位夹紧方式···················································································103.3电磁无心夹具的设计···················································································113.4无心夹具的定位误差···················································································153.5电磁无心夹具各部件设计图及参数的确定···················································164.检测装置的设计················································································184.1检测装置的设计目的和意义·········································································184.2检测装置设计······························································································185磨床各部件及其参数的确定·································································205.1.导轨···········································································································205.2.往复移动速度·····························································································205.3.磨架电动机功率·························································································20设计总结·························································································21致谢·····························································································23参考文献·····························································································24河南工业大学1前言现今轴承生产中，套圈磨削工艺及专用磨床不能满足高精度，高效率的要求，与国外相比存在着一定的差距。工艺设备的落后是国产轴承精度低，性能差，成本高以及在国际市场上竞争力低的主要原因。在所有轴承加工设备中，内表面磨床的水平具有表征意义。这主要是磨削孔径限制了砂轮尺寸及相应的系统结构和几何参数，从根本上限制了工艺系统的的刚性。内圆磨削速度要从砂轮主轴的转速的提高寻找出路，相应的就带来了高速主轴轴承的制造，应用装配技术和高速下的振动及动平衡一系列要求。轴承套圈内径公差严格，在大批量与高效率的生产条件下，难以用定程控制尺寸，必须配用各式主动测量系统，从而增加了内圈磨床结构及尺寸的复杂性。该课题来源于生产实践。在深沟球轴承内圈的加工中，内圆磨削是一道关键工序。其原因是：受孔径限制，砂轮尺寸小，砂轮消耗快，影响磨削效率和质量。现代磨削技术在不断的发展和提高，对于轴承内圈内圆的磨削，越来越要求磨床具有高精度、高效率和高可靠性，而传统的手动和半自动内圆磨床难以满足使用要求，因此设计开发全自动内圆磨床则显得尤为重要。根据任务分工，我主要负责设计机床的工件定位夹紧系统。设计过程中，通过翻阅大量的通用机床的设计资料，并总结设计机床的主要特点，从而得出了该机床的夹具装配图。虽然各种机床的功能和要求不同，但就其磨削原理而言，同属于内表面磨削，其运动方式和总体布局也基本相同，大多数部件通用。目前，国内各厂对中高级精度轴承多采用二次磨削，为了改变这种情况，拟用一次磨削代替且达到终磨技术要求。要在大批生产高效的条件下，满足上述技术要求，从磨床设计的观点来看，可以归结为磨削几何精度、尺寸精度及效率三个方面的要求。用因果分析尺寸精度、几何尺寸及磨削效率的影响因素，从而选择最佳装夹部件方案，在考虑运动图的设计布局及造型设计，最后决定最佳的方案。河南工业大学21全自动轴承内圈内圆磨床概述1.1磨削的基本原理1.1.1磨削基本原理磨削加工可分为一般磨削和高光洁度磨削（即精密磨削，超精磨削，镜面磨削）两种。对于一般磨削，砂轮可当作一把多刀多刃的铣刀，每一颗磨粒相当于一个刀齿，每一个粒尖相当于一个“刀刃”。但他与铣刀又不同的地方就是砂轮有无数的刀齿，且刀齿的排列和刀齿的角度都是及不规则的。高速旋转的每一个“刀齿”，在切削力的作用下，从工件表面上切除一条薄层的切屑，并在工件表面上摩擦发热而产生火花。这样无数磨砺切削的结果，就把工件表面要切除的金属磨去，形成光滑表面。对于精密磨削，超精密磨削和镜面磨削，光滑表面的形成与一般磨削相似，但也有自身的特点。高光洁度磨削是由砂轮通过精细修整后形成等高的微刃切削作用和适当接触压力的摩擦抛光作用，使工件表面获得高的光洁度。1.1.2轴承套圈内圆的磨削原理与特点（1）.基本原理：下图为滚动轴承内圈内孔的磨削原理图。fgngwnofwa图1-1滚动轴承内圈内孔磨削原理图磨削时，工件径向进给，砂轮轴轴向往复移动，在粗进给和精进给磨削之间，往往需要修整砂轮。修整时，砂轮退出内孔并在修整器位置往复运动一次，修整器就在砂轮表面去除一层磨料。每修整一次，就必须有一次补偿进给量Δa,Δa的大小应根据生产条件经验合理确定，一般其数量级为1-10微米。在内圆磨削中，工件进给一般由机械控制，也有用步进电机控制的。砂轮转速由电主轴控制：砂轮轴向长距离往复运动由油缸控制，而其往复振动则有偏心装置河南工业大学3控制。（2）.轴承内圈内圆磨削的特点：(A).砂轮刚度低内表面磨削时，砂轮受内径限制，常制成较细的悬臂梁状，刚度很低：刚性差，易于变形，从而引起较大的尺寸和形状误差：砂轮轴无进给光磨恢复变形时间较长，生产率很低。(B).磨削条件差内表面磨削时，砂轮直径很小，为保证一定的磨削线速度，砂轮轴转速极高，要上万转，很容易引起磨削系统的振动。在磨削时，砂轮与工件接触面积大，磨砾极易钝化，且自锐性不能充分发挥，产生热量多，冷却液很难进入磨削区，工件表面极易烧伤。1.2全自动轴承内圈内圆磨床的加工对象、范围及要求1.2.1机床的加工对象该磨床主要用于大批量生产中高级精度的深沟球轴承内径的磨削。主要用于磨削轴承套圈内径，也适合磨削其他环形零件的内径，最适合大批量全自动化生产。1.2.2机床的加工范围该磨床所加工轴承套圈的规格为：磨孔直径：φ10-30毫米最大磨削深度：30毫米最大工件外径：φ52毫米加工余量:0.2-0.35毫米加工宽度:9-30毫米加工质量:高于轴承国家标准对于P0级精度的轴承要求1.2.3工件的加工精度作为精密的机械元件，滚动轴承工作性能能直接影响逐级的工作性能，甚至于装在主机关键部件的轴承的工作能力，几乎决定了该逐级的工作性能，河南工业大学4除高精密轴承外，象耐高温、耐低温、防锈、防震、高速、高真空、和耐腐蚀等具有特殊性能要求的轴承的质量指标也是十分严格的。一般来说，滚动轴承应具有高的寿命,低的噪音，小的旋转力矩和高的可靠性，这些基本性能要达到这些要求，就必须在机械加工工艺上首先确保轴承零件套圈的以下指标：旋转精度：要求轴承的套圈的几何形状精度和位置精度不超过几微米。尺寸精度：要求套圈的尺寸精度在几微米之内。粗糙度：安装表面粗糙度Ra值不大于0.63μm-0.32μm，尺寸稳定度：在长期存放和工作时没有明显的尺寸和形状变化。质量指标：尺寸公差7微米：圆度3微米：粗糙度0.04μm河南工业大学52自动轴承内圈内圆磨床总体设计与布局2.1机床的主要运动及参数分析2.1.1机床应提供的主要运动分析为实现正常的内圆磨削，所需要的切削运动和辅助运动如下图所示。VrnwVf(f1,f2,f3)VdVa图2-1内圆磨削切削运动和辅助运动图图中Vf-横向进给运动：Vr-纵向往复运动：Vd-修整运动：Va-砂轮与工件的接近运动：Ng-砂轮转速：Nw-工件的旋转运动。2.1.2机床的运动参数及动力参数磨架最大纵向行程(mm)150磨架往复振幅(mm)14(无级调速)磨架往复频率(次/分)150-450(无级调速)砂轮轴型号GDZ-36GDZ-48GDZ-60砂轮轴转速(rpm)360004800060000砂轮轴功率(KW)5.03.52.5工件轴转速(rpm)低速45056710高速90011341420工件架最大横向移动量(mm)25河南工业大学