汽车单级主减速器设计

汽车单级主减速器设计

任务书

1．设计的主要任务及目标

通过调研和查阅相关资料文献，掌握汽车单级主减速器主要用途和工作原理。应用所学相关基础知识和专业知识，分析单级主减速器结构、载荷，对主要受力件强度进行计算分析，应用CAD三维造型或二维设计技术完成课题总成和关键零件结构设计和计算说明书，按照学校要求编写毕业设计论文。

2．设计的基本要求和内容

1）掌握单级主减速器的结构及工作原理。绘制结构简图和原理简图；

2）了解零部件材料及制造、热处理工艺；

3）了解单级主减速器的失效模式；

4）制作单级主减速器的装配总图；

5）对单级主减速器及关键零件结构进行计算分析，重点是对失效件的分析；

6）编写毕业设计论文，总结设计取到的效果与体会，提出自己的论点和改进建议等。3．主要参考文献

《汽车车桥设计》

4．进度安排

汽车单级主减速器的设计

摘要：由于行驶中的汽车发动机的转速通常在两千到三千转每分钟，如果只通过变速箱来减速的话，那样会有一个很大的减速比，从而增大了齿轮的半径，继而增大了变速箱的尺寸，既不经济又不合理，另外，转速下降，而扭矩必然增加，也就加大了变速箱与变速箱后一级传动机构的传动负荷。所以，在动力向左右驱动轮分流的差速器之前设置一个主减速器。

主减速器的存在有三个作用，

第一是改变动力传输的方向，由上图可以看出动力传递出变速器是纵向的力距，通过减速器，力矩发生了90度的转变，从而传递到半轴形成横向的力矩，从而驱动车子前进。

第二是作为变速器的延伸为各个档位提供一个共同的传动比。有了这个传动比，可以有效的降低对变速器的减速能力的要求，这样设计的好处是可以有效减小变速器的尺寸，使车辆的总布置更加合理。

第三也是最重要的就是减速增扭，根据功率的计算公式W=M*v（功率=扭矩*速度）当功率一定时，减少传动速度，能够增加扭矩，从而增加驱动力，这也是汽车上坡采用低档的原因。

关键字；变速器，减速器，传动轴

Automotive design single-stage main gear

Summary：Since moving automobile engine speed is usually 2000-3000 rpm , if only to slow down through the gearbox , then that will be a big reduction ratio, thereby increasing the radius of the gear , which in turn increases the gearbox size , neither economic nor reasonable , in addition, the speed decreased, while torque will increase, it increases the load transmission gearbox and rear gearboxes level transmission mechanism . So, before power to the left and right wheels to set up a triage differential final drive .

There exist three main reducer role

The first is to change the direction of power transmission from the power transmission can be seen that the torque transmission is a longitudinal , through a speed reducer , torque in a shift of 90 degrees , thereby transferring torque to the transverse axle is formed so as to drive the car forward.

Second, as an extension of a common transmission gear ratio for each gear position . With this ratio , can effectively reduce the transmission capacity reduction requirements , benefits of this design is that it can effectively reduce the size of the transmission , so that the general arrangement of the vehicle is more reasonable.

The third and most important is the reduction by twisting , according to the power of the formula W = M * v ( power = torque * speed ) when the power is constant , the speed reduction gear , the torque can be increased , thereby increasing the driving force , which is the car reasons for the use of low-grade slope .

Keywords; gearbox , reducer , drive shaft

目录

1 绪论 .................................................................................................................................. 1 2 单级主减速器的设计方案 .............................................................................................. 2 2.1汽车单级主减速器的结构及工作原理 ......................................................................... 2 2.1.1主减速器的类型 ......................................................................................................... 2 2.1.2主减速器的布置及作用分析 ..................................................................................... 4 2.1.3主减速器的减速形式 ................................................................................................. 5 2.1.4主减速器主、从动锥齿轮的支承方案的选择 ......................................................... 6 2.2主减速器的基本参数选择与设计计算 . (7)

2.2.1主减速比0i 的确定 (7)

2.2.2主减速齿轮计算载荷的确定 ..................................................................................... 8 2.3主减速器锥齿轮基本参数的选取 (9)

2.3.1主、从动锥齿轮齿数1z 和2z ..................................................................................... 9 2.3.2 节圆直径和端面模数的选择 .................................................................................. 10 2.3.3 螺旋角的选择 ........................................................................................................... 11 2.3.4 齿面宽的选择 ........................................................................................................... 11 2.3.5螺旋锥齿轮螺旋方向 ................................................................................................ 11 2.3.6 齿轮法向压力角的选择 .......................................................................................... 12 2.4 主减速器锥齿轮几何尺寸的计算 .............................................................................. 12 2.5螺旋锥齿轮的失效形式 ............................................................................................... 15 2.6螺旋锥齿轮的强度校核 ............................................................................................... 16 2.6.1 单位齿长上的圆周力 .............................................................................................. 16 2.6.2 轮齿的弯曲强度计算 .............................................................................................. 17 2.6.3 轮齿的表面接触强度计算 ...................................................................................... 18 2.7锥齿轮的材料及热处理 ............................................................................................... 19 3 主减速器轴承的计算 ...................................................................................................... 20 3.1作用在主减速器齿轮齿宽中点的圆周力 ................................................................... 21 3.2 主减速器轴承载荷的计算 (22)