链式传动系统设计(课程设计)(17)

17 1at α=arccos

11a d d d = arccos 782.75921.66 =27.9850 2at α=arccos

22a d d d = arccos 618.242706.223 =22.7720 αε=π

21［1z (tan 1at α-tan t α)+2z (tan 2at α-tan t α)］ =π

21[35×()︒-︒363.20tan 985.27tan +117×()︒-︒363.20tan 772.22tan ]=1.798 βε=n m b πβsin =

π0.22911.11sin 55︒

⨯ =1.714 由《机械设计》式5-43计算εZ

746.0798.11

1===α

εεZ 99.0cos ==ββZ

b β= arctan(tan βcos t α)=10.6020

H Z =t t b

a a sin cos cos 2

β= ︒︒︒

6847.20sin 6847.20cos 3841.14cos 2 =2.421 由《机械设计》式5-38计算齿面接触应力H σ H σ=H Z E Z εZ βZ u 1

u 222

2+bd KT =2.45×189.8×0.746×0.99

× 3.313.3382.7155148570

558.122+⨯⨯⨯⨯ =503MPa<[H σ]=609 Mpa 安全

6.4验算齿根弯曲疲劳强度

由《机械设计》式5-44得：

F σ=n

m bd KT 11

2Fa Y sa Y εY βY ≤][F σ

1v z =1z /β3cos =35/ ︒2911.11cos 3 =37.114 2v z =2z /β3cos =117/︒2911.11cos 3=124.065 查《机械设计》图5-14得：1Fa Y =2.47,2Fa Y =2.22