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3. 查表并查图选取齿宽系数,区域系数,材料的弹性影响系数,.............................8
4. 计算接触疲劳强度用重合度系数......................................................................8
.......................................................................................................................8
.......................................................................................................................8
.......................................................................................................................9
5. 计算接触疲劳强度许用应力.............................................................................9
查图得小齿轮和大齿轮测接触疲劳极限分别为、....................................................9
计算应力循环次数:..........................................................................................9
.......................................................................................................................9
.......................................................................................................................9
查图取接触疲劳寿命系数、。..............................................................................9
取失效概率为 1%、平安系数 S=1,由式子得.......................................................9
取和中的较小者作为该齿轮副的接触疲劳许用应力,即...........................................9
.......................................................................................................................9
2) 试算小齿轮分度圆直径.................................................................................9
.......................................................................................................................9
.......................................................................................................................9
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〔2〕调整小齿轮分度圆直径...............................................................................9
1〕计算实际载荷系数前的数据准备。..................................................................9
1、圆周速度 v。...............................................................................................9
.....................................................................................................................10
2、齿宽 b......................................................................................................10
.....................................................................................................................10
2)计算实际载荷系数。.....................................................................................10
1、查表取使用系数。......................................................................................10
2、根据、7 级精度,查图得动载荷系数。..........................................................10
3、齿轮的圆周力。.........................................................................................10
.....................................................................................................................10
查表得齿间载荷分配系数..................................................................................10
4、查表用插值法查得 7 级精度、小齿轮相对支承非对称布置时,得齿向载荷分布系数。
由此,得到实际载荷系数..................................................................................10
.....................................................................................................................10
3)由式子得,可得按实际载荷系数算得的分度圆直径............................................10
及相应的齿轮模数...........................................................................................10
.....................................................................................................................10
二、按齿根弯曲疲劳强度设计............................................................................10
〔1〕由式子试算模数,即................................................................................10
.....................................................................................................................10
1) 确定公式中的各参数值.................................................................................11
1、 试选。.....................................................................................................11
2、 由式子计算弯曲疲劳强度用重合度系数。......................................................11
.....................................................................................................................11
3、 计算。.....................................................................................................11
查图得、。应力修正系数、。小齿轮和大齿轮的齿根弯曲疲劳极限分别为、。弯曲疲劳
寿命系数、。..................................................................................................11
取弯曲疲劳平安系数 S=1.4。由式子得..............................................................11
.....................................................................................................................11
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