Transmission gear engagement mechanism and method of operation

摘要

A transmission (12) for a vehicle (10) includes a gear shaft (40) having a fluid passage (106), and a gear (42) having a first bore mounted to the gear shaft (40). The gear has a first axial face (74) with a plurality of teeth (76), and a first undercut (78) at each of the first bore and the first axial face. A shift collar (64) has a second bore (88) mounted to the gear shaft (40). The second bore (88) is axially movable and rotationally fixed relative to the gear shaft (40). The shift collar (64) has a second axial face (92) with a plurality of teeth (94), and a second undercut (98) at each of the second bore (88) and the second axial face (92). The teeth (94) of the second axial face (92) are enmeshable with the teeth (76) of the first axial face (74). An annular piston (66) is slidably mounted to the gear shaft (40) and positioned within each of the first undercut (78) and the second undercut (98). The annular piston (66) is configured to move the shift collar (64) away from the gear using pressurized fluid in the fluid passage (106).

主权项

1. A transmission for a vehicle, comprising:
a gear shaft having an internal fluid passage; a gear having a first bore carried about said gear shaft such that said gear circumferentially surrounds said gear shaft and is rotatable relative to said gear shaft, said gear having a first axial face with a plurality of teeth, and a first undercut at each of said first bore and said first axial face, said first undercut at least partly defining a first annular cavity circumferentially surrounding said gear shaft and extending radially from said gear shaft to a portion of said gear; a shift collar having a second bore carried about said gear shaft, said second bore circumferentially surrounds said gear shaft and being axially movable and rotationally fixed relative to said gear shaft such that said shift collar rotates with said gear shaft, said shift collar having a second axial face with a plurality of teeth, and a second undercut at each of said second bore and said second axial face, said second undercut at least partly defining a second annular cavity circumferentially surrounding said gear shaft and extending radially from said gear shaft to a portion of said shift collar, said teeth of said second axial face being enmeshable with said teeth of said first axial face to cause said gear to rotate with said shift collar; and an annular piston slidably carried about said gear shaft such that said annular piston circumferentially surrounds said gear shaft and positioned within each of said first annular cavity and said second annular cavity such that said annular piston is at least partly disposed radially between said gear shaft and each of said gear and said shift collar, said annular piston moving said shift collar away from said gear when said annular piston is subjected to pressurized fluid from said fluid passage of said gear shaft entering at least one of said first bore and said second bore.