1 A common V belt and ring synchronous belt transmission, with known models for A, two rounds of base diameter is 150 mm and 400 mm respectively, the initial center distance A = 4500 mm, the small belt wheel speed of 1460 r/min. Try please: ( 1) Small pulley Angle; ( 2) Selected with the baseline length Ld; ( 3) Not considering the elastic slide of belt drive big belt wheel speed; ( 4) Sliding rate? = 0. 015 when large pulley's actual speed; ( 5) To determine the actual center distance. 2, the ordinary v-belt transmission used in the motor in question 1 and material between the mill, reduction drive, work 8 hours a day. The known motor power P = 4 kW, speed n1 = 1460 r/min, try for the root of the number needed to type A belt. 3, a common V belt drive transmission power for P = 7. 5 kW, belt speed? 吗? = 10 m/s, tight tension is loose edge pull two times, namely the F1 = 2 f2, try pulling force, loose and tight side tensile and have xiao. 4, design a crusher with common V belt transmission. Known to the motor rated power is P = 5. 5 kW, speed n1 = 1440 r/min, driven wheel for n2 = 600 r/min, allowed error of plus or minus 5%, two shifts work, hope center distance less than 650 mm.