=1.88-3.2×(1/29+1/116)
=1.742
Z==0.868
(d)KH=1/ Z2=1/(0.868)2=1.33
(e)查取齿向载荷分布系数K=1.2
所以载荷系数K:K=KAKV KH K=1.0×1.3×1.3×1.2=2.028
转矩T1=209.18Nm=209180Nmm
(f)查取齿宽系数=0.3
(g)查得弹性影响系数=189.8
(h)查得区域系数=2.5
(i)查取材料接触疲劳强度极限:查图得,小齿轮为=580Mpa,大齿轮=540 Mpa
(j)计算应力循环次数N
N=60 thn1=60×1×24000×486.67=700.80×106
N==280.32×106
(k)查表得:对N1,取m1=14.16,对N2取m2=17.56(m为疲劳曲线方程指数)
ZN1===1.025
ZN2==1.075
(l)查得接触疲劳强度最小安全系数S=1.05
(m)计算许用接触应力[]:
[]===566.19 Mpa
[]==552.86 Mpa
(n)小齿轮大端分度圆直径d1:
=
=120.14mm
即d1=120mm
(3)确定主要参数:
(a)大端模数m:m=d1/z1=120/26=4.62,即m=4.6
(b)大端分度圆直径d1=m z1=26×4.6=119.6mm
d2=mz2=239mm
(c)锥距R:R==133.72
(d)齿宽b:b=R=40.11,取整b=40
(4)轮齿弯曲疲劳强度验算:
(a)齿形系数YFa1=2.65, YFa2=2.15
(b)应力修正系数YSa按当量齿数查图得:
YSa1=1.67,YSa2=2.25
(c)重合度系数Y:Y=0.25+=0.25+=0.68
(d)齿间载荷分配系数KFa:KFa=1/ Y=1/0.68=1.47
载荷系数K:K=2.028
(e)齿根工作应力:=
=
=202.21N/mm2
==221.04N/mm2
(f)弯曲疲劳极限由图查得:=330 N/mm2
310N/mm2
由表查得:N0=3×106,m=49.91(为疲劳曲线方程指数)
(g)弯曲寿命系数YN:YN1===0.9
YN2==0.91
(h) 由图查得尺寸系数:YX=1.0
(i)弯曲疲劳强度最小安全系数SFmin查得:SFmin=1.25
(j)许用弯曲疲劳应力:
===237.6N/mm2
===225.68 N/mm2
(k)弯曲疲劳强度校核:
= 237