Tham khảo tài liệu 'illustrated sourcebook of mechanical components part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 5-16 F - - F 12 sin a Numerical example A centrifugal clutch shoe has a radius of in. and a width of lining of in. Lining pressure is not to exceed 100 psi. Angular length of lining is Ó 108 deg and the link is at an angle of a 48 deg. The shoe is pivoted at a distance h of 4 in. from the center. Total inward spring force of both springs is 15 lb. Weight of shoe is 3 lb with its center of gravity at a radius of in. As there are linings on the market with a different coefficient of friction for values of fl of . and find the corresponding values of forces Q R and F F. Find the torque T the corresponding slipping rpm and the horsepower per shoe. Plot the curve for hp vs fl to determine the best value for fl. Solution By Eq 7 fl 4 4 tan e 4 By Eq 2 A ị 100 cos e - 1861 cos e By Eq 3 Nw sin 9 2. Floating-link design Clutches 5-17 By Eq 6 T 2m 2 100 cos 0 11 149 X cos é From Eq 10 Then n - 60 w Fe Z7T also Tn hp 10WQ The calculations are best carried out in tabular form see table . Thus for the case of ịi tan d 0 8 cos 0 N -1861 1b N 1b By Eq 4 5 and 8 F 1b Fw 0J lb Q V 2 2 1852 lb By Eq 9 a _ _ n 1cncf tan 3 1091 lool 3 8 By Eq 11 and 12 R 371 lb sin 48 Ff F -F 33 1583 lb sin 48 F 1583 15 1598 lb Thus T 11 149 1102 Ib-in. n V1598 2019 rpm 4. Variation of horsepower with coefficient of friction for the floating-sink clutch analyzed in the numerical example. Note that best gripping power ss obtained with shoe-linings having a coefficient of about . Calculations for various linings Li tan 0 0 N Fr F c N F . Nir4-F v .- 2 o 8 75 960 1852 16 283 130 1818 .
