Question

Problem 13-34 A compound reverted gear train is to be designed as a speed increaser to provide a total increase of speed of exactly 40 to 1. Use spur gears with a 20° pressure angle and a diametral pitch of 6 teeth/in. (a) Specify appropriate numbers of teeth to minimize the gearbox size while avoiding the interference problem in the teeth. (b) Determine the gearbox outside dimension Y, assuming the wall thickness of the box is 0.75 in, and allowing 0.5 in clearances between the tips of the gear teeth and the walls. Problem 13-34

Answer 1

Given that,

2

Solution - Given the train value e=yo We know that Product Product of driven tooth numbers. of drinking teath numbers Na - Nu ee 4o Nz. Ng to bind the exad value we can write above equation as Now ( 85) -M5 Thus and 5 8 Ny N5 Now considering the distances between shants we get + + eelor Thus () + Ng ap + we get a 2 Now diametral kitch P = N or d = N / Ny N5 QP * Na+Ng = Nyt Ng Now for ao pressure angle minimum number of teeth to avaid interference as 16. Now choosing Ng = 16 Na - Ng = (8)(16) = 128 Now from ecuation () we get: - 198+18 - Nu TNG - Nut Ng=144 Now from equation (II) we get Nu = 500 Thus from equation (2) we get IN5+NG → २५ and Nu=5N8 5 (24) ► Thus number of teeths on gears are: - Na = tas 2144 D NG Nu = 120 N3 = 16 Ny = 120 ng 24

diametral pitch, p= 6 teeth linch (b) given, = 21.33 inch 2.66 inch d4 = 120% = 20 inch PCD=N/6 da = 128/6 dg = 1616 = d5 = 24/6= 4 inch Also, clearance =0.5 and Allowance thickness=0.75 inch y= 2 (4+C) + d2+ d3t (des de = 2 (0.75+0.5) 7 2133 + 2.66 + (20- * (202) = 34.49 inch I thickness 7 It Thank you. Remove Negative Rating And repvote.