Question

Problem 1. Design a reverted gear train for a transmission with three speeds and reverse. For an input speed of 450 rpm to the driving shaft (green), the driven shaft (teal) should have output forward speeds of 75, 300, and 450 rpm, and an output reverse speed of 150 rpm. Assume all gears have a diametral pitch of 10. Gear A (24 teeth) and Gear D (36 teeth) are in constant mesh. Determine the numbers of teeth for ALL six gears (B, C, E, F, G, and H). Clearly show your work. Note that there may be more than one solution. Hint: The center distances between each gearset must be the same! D D m G H First Gear Second Gear Reverse Gear Third Gear (direct drive)

Answer 1

First hear is de NA = 450 pm {input] Np = ? A TA = 24 teeth TO = 36 testu NA NO To TA » No = 450 x 24 36 X 3 = 300 pm > No = NF = 300 rpm w Same shatt} out put speed in ist ist gear Nc 75 pm Nc NE 75 300 TC-4 TE т TA + To Tc + TE دک reverted gear train ] 24 +36 TC + TE 60 Tc + TE 2) solving can 0 and 60 = 4TR + TF 5 TE=60 TE=12 T = 4T; - 48 TE = 12 , Tc=48 CS Scanned with CamScanner

and gear To TA No = 300 rpm. ND No = NE = 300 opm same shaft so that each goar in the shaft) А D rotates same spm B E Pole NE Ng To TE To = TE NB = 300 rpm Tatto To + TE 60 ТА+ ТЕ 2 TB 60 TB 30 teeth TE = 30 teeth good gear direct drive input and output shaft sotules in some me } opm 450rpm

Reverse Sear Gean H is a idler to reverse the rotation, TATTO > Te + Th between a space There is gear a and c Co > c + Ta. Te=48 12 > TG number teeth in Gear a should be less than 12, use idlen to reverse the rotation. there only we Com Na = 300 pm To <12 knowns. D Nc = 150 rpm Te = 48 H we have to reduce the speed from and nevene to 150 rpm Na - 2007 300 pm Ne =1507pm the sotation, H Le anume Tu= 10 and Hi-5 12 teeth 5 teeth NG = THI Ta 300 x 10 = 600= 55 oferta NH 300 pm 150 rpm 5 THE To 150 x48 = 600 NH = 12 172 Nwq = Nite = 600 rpms {same shaft}. Ta = 10 <12 speed reclution 2 Conditions satisfied so that the assumed vakrees q teeth number is one solution CS Scanned with CamScanner