1) The figure shows a countershaft carrving two V-belt pulleys and mounted in bearings at O and C. Pulley A receives power from a motor through a belt with the belt tension shown. The power is transmitted through the shaft and deliverad to the belt on pulley B. Assume the belt tension on the c) For static analysis using a design factor ng = 2.8, use distortion energy theory to determine the loose side at B is 15 percent of the tension on the right side. The shaft is to be made of AISI 1035 CD steel. a) Determine the tensions in the belt on pulley B, b) Find the reaction forces, minimum safe diameter of the shaft at point A.

42. The static deflection at the center of the steel shaft in Fig. 3-53 is equal to 0.35 mm. Find the value of the critical speed. Shaft is steel. Ans. n = 1810 rpm. Design of Shafts Chap. 3 248 t. 50 30 1"dia 10" 10" Figure 3-52 Problem 41. 10 kg 10 kg C B 375 600 mm 375 Figure 3-53 Problem 42.

An electric motor running at 970rpm is used to drive a rock crushing machine with a design power of 32 kW. A 33oz ducking weight flat belt drive is proposed with a tension ratio of R = 4 and belt width b = 120 mm. The pitch diameter of the driving pulley (on the motor-end) is 320mm. a) What is the mass per mm width per m length per ply in kg/mm/m/ply? Number (exact value) b) What is the maximum working tension per mm width per ply in N/mm/ply? Number (exact value) c) Calculate the belt velocity in m/s Number (+/-1%) d) Determine the number of belt plies required. Your answer should be an integer number (no decimals). Number (exact value)

Compute the contact stress number for the gear fain pair driven directly by an electrical motor. The driven machthe is concrete mixture with moderate shock, the other data are given below. Ks= 1.00, Km 1.21, Vt =1527 St/min, Av-11 Pd= 6, np= 1750rp.m, Np 20, No= 70, F=2.00/n Tp = 900ib, Dp= 3:333 in The material used for pioin an gear is Steel