圈上泽充大华 Square thread-Load Raising Summing the forces in vertical and horizontal directions gives: ∑Fx=PR-Nsin入-fN cos=0 ∑Fy=F-Ncos+fN sin=0 f-frictional coefficient V 圆上泽夫通大学 Load Raising-Tightening Screw Eliminating the normal force gives: (sin f cos a) P=F (cos a-f sin tan2=l/πd。 Dividing both numerator and denominator by cosλgives: P F[(lπda)+f] 1-(flπd.） 2121  Summing the forces in vertical and horizontal directions gives: Fx = PR - N sin  - f N cos  = 0 Fy = F - N cos  + f N sin  = 0 f — frictional coefficient Square thread——Load Raising  Eliminating the normal force gives:  Dividing both numerator and denominator by cos  gives:     sin cos cos sin tan 1 R m f P F f d             1   m R m F ld f P fl d          Load Raising- Tightening Screw