Download
1 / 16
450 likes | 1.43k Views
Gear Train. Three-Speed Transmission . Synchronizers . cone clutch f. Before the teeth can engage, the cone clutch engages first, which brings the selector and gear to the same speed using friction. First Gear. Second Gear. Third Gear (Direct Gear).
E N D
Synchronizers cone clutch f Before the teeth can engage, the cone clutch engages first, which brings the selector and gear to the same speed using friction.
Shown below is a three- speed transmission. Gears 4,5 and 6 are free to spin about their shaft, while gears 3,7,8,9,10 and 11 are keyed to their respective shafts. Gear 10 is an idler gear whose centre is not in line with those of gears 6 and 11. C1 and C2 are synchronizers that fix one gear to the shaft each time, so power is transmitted from the input shaft to the output shaft. Idler gear 10: reverses the direction of rotation without changing the gear ratio
Assume the following parameters: • All gears have a diametral pitch p=12 • center –to –center distance between input shaft and counter shaft C=4 in • approximate speed ratios • first gear e1=0.2, second gear e2=0.51, third gear e3=1, reverse er=-0.22 • idler gear: number of teeth =16, pitch diameterD10= D6/3, centre- to centre distance C10/11=2 in
Questions: • Calculate the gears’ teeth number • Calculate the gears’ diameters
Solution: • Because all gears are to have the same module and meshing gears must share a common center –to –center distance, r is pitch radius d is pitch diameter
We know that the relationship between the number of teeth and the pitch diameter is where P is the diametral pitch. The first gear speed ration is (1)
The second gear speed ration is (2) The reverse gear speed ration is (3)
