Two-speed planetary transmission with singular actuator

摘要

A planetary gear transmission is provided having a sun gear, ring gear and planet carrier mounted in a housing. A plurality of compound planet gears are rotatably mounted to the planet carrier. The planet carrier is connected to one of either an input shaft or an output shaft while the ring gear is connected to the other of either the input shaft or output shaft. A clutch engageably and disengageably couples the sun gear for rotation with one of the input or output shafts to which the planet carrier is coupled. A brake engageably and disengageably fixes the sun gear against rotation relative to the housing. A hydraulically engaged/spring disengaged non-rotating piston is mounted in the housing and is slidable in response to fluid pressure between an engaged position for engaging one of the clutch and the brake and a retracted position for disengaging the one of the clutch and the brake. Whereby the transmission operates in a first range when the clutch is engaged and the brake is disengaged and operates in a second range when the brake is engaged and the clutch is disengaged.