问答题
车削分度圆直径d1=28mm，齿形角α=20°，轴向模数研：2.5mm的双头米制蜗杆，求蜗杆的齿顶圆直径da1、齿根圆直径df1、导程角γ、轴向齿厚sx及法向齿厚sn。
【正确答案】已知d1=28mm、α=20°、m=2.5mm、z1=2
da1=d1+2m=28mm+2×2.5mm
=28mm+5mm=33mm
df1=d1-2.4m=28mm-2.4×2.5mm
=28mm-6mm=22mm
tgγ=Pz/πd1=z1πm/πd1=z1m/d1
=2×2.5mm/28mm=0.17857
γ=arctg0.17857=10.12459°
=10°07'29"
sx=πm/2=3.1415×2.5mm/2
=3.927mm
da1=d1+2m=28mm+2×2.5mm
=28mm+5mm=33mm
df1=d1-2.4m=28mm-2.4×2.5mm
=28mm-6mm=22mm
tgγ=Pz/πd1=z1πm/πd1=z1m/d1
=2×2.5mm/28mm=0.17857
γ=arctg0.17857=10.12459°
=10°07'29"
sx=πm/2=3.1415×2.5mm/2
=3.927mm
【答案解析】