1. The figure below is a spur gear train drive and gear 2 is the inlet of the gear train. It transfers 12 kw of power at 1200 rpm. Gear 3 and 4 have 60 and 20 teeth respectively and are made with 20° pressure and full-depth teeth. The desired speed for the output shaft is 32 rpm. a. Find the minimum number tooth on gear 2 to obtain 32 rpm at the output and confirm its validation for interference-free power transfer. b. Find the speed ratio at each gear set using the results obtained at "a"(above). c. Determine the rotational speed of each gear (n2, n3, n4, and ns) using the results obtained at "a"(above). d. Find the torque of each shaft (Tin, Te, Tout) assuming that there is no frictional loss during the power transfer. e. Determine the radial, tangential and total forces transmitted at the last gear set assuming a module as m=4 mm, and draw the free body diagram of gear 4 showing the forces and torques.

b) Figure Q1b shows a compound gear train with Gear A as the pinion (or driver) with an input Power (Pin) of 600 W at Gear A. If Gear A rotates at 139.70 rpm and engages with Gear B, calculate the angular velocity (w) in rad/s for Gears B, C & D; and the input torque (Tin) in at Gear A and output torque (Tout) at Gear D. The number of teeth (N) for gears A, B, C & D are 62 teeth, 34 teeth, 42 teeth and 22 teeth, respectively. Assume 100% efficiency and no frictional losses; and give your answers to two decimal places. GEAR A GEAR C GEAR B GEAR D

A gear box has an input speed of 1800 rev/min clockwise and an output speed of 400 rev/min The input power is 25kW and the efficiency is 90%. Compute the input torque                                                                                                                                                  the output power                                                                                                                                                       3. the output torque

Explain the following terms with reference to Spur gears: ①Pitch circle ② pressure angle ⑤ Backlash 6 Base Circle 3 circular pitch (4) Addendum