REDUCTION GEAR SHIFTING DEVICE.

摘要

This reduction gear shifting device is employed in shifting the working speed of an agricultural tractor and is adapted to shift, in a simple manner, between a certain set rotational speed and reduced rotational speed slightly lower than the set speed. According to this device, the sun gear (30b) of a planetary gear mechanism is either coupled to an output shaft (12) or rendered stationary via a clutch (41) and a brake (42) provided at the axial side of an internal gear (7a). A supporting frame (17) for journaling the shaft (12) internally accommodates the clutch (41) and the brake (42) together with the internal gear (7a) to thereby install them at the front transmission case (3). The clutch (41) and the brake (42) are of a frictional multidisk type in which at least one frictional plate (33) in one member is connected to at least one in the other member so as to move in the same direction. The brake (42) is so adapted that the supporting frame (17) serves as a stationary side member. The piston (40) for operating the clutch (41) and the brake (42) is movably fitted over a collar (36) fitted over the outside of a center boss (30c) of a housing (30) incorporating the sun gear (30b).