The invention discloses a two-
gear transmission. The two-
gear transmission comprises a normal meshing tooth two-way overrunning
clutch, a
shunting assembly and a
brake; and the
shunting assembly comprises an input element and two
shunting elements, one shunting element is directly connected with the output end of the normal meshing tooth two-way overrunning
clutch, the other shunting element is directly connected with the input end of the normal meshing tooth two-way overrunning
clutch and externally provided with the
brake, the input element of the shunting
assembly serves as input of the two-
gear transmission, and output of the normal meshing tooth two-way overrunning clutch serves as output of the two-gear transmission. When the
brake does not work, two transmission paths simultaneouslysupply power to achieve joint driving, and the
low speed and the large torque are output; and when the brake works, one transmission path is locked, and the high speed and the low torque are output.According to the two-gear transmission, shifting of two gears can be achieved only through one brake, the requirements for a
control system are low, the gear shifting mode is simple and reliable, thegear shifting process is steady and simple, power failure can not occur in the gear shifting process, and the two-gear transmission is an ideal transmission of an electric automobile.