渐开线方程r=db/2ang=t*90s=(pi*r*t)/2xc=r*cos(ang)yc=r*sin(ang)x=xc+(s*sin(ang)y=yc-(s*cos(ang)z=0关系d=m*z/cos(beta)at=atan(tan(a)*cos(beta)DB=D*cos(at)df=d-2*m*(ha+c)-x)da=d+2*m*(ha+x)d7=dad6=dd5=DBd4=df