Two-stage speed-change output device and electric vehicle using same

A two-stage speed-change output device, comprising:

• a main axle;
• a motor assembly;
• a first speed-change assembly;
• and
• a second speed-change assembly mounted on the main axle, the first speed-change assembly and the second speed-change assembly being mounted inside an output shell by means of a first one-way clutching element and a second one-way clutching element that are operable in a forward direction, wherein the motor assembly is operable to rotate in a backward direction to drive the first one-way clutching element of the first speed-change assembly to drive the output shell to rotate in the forward direction and to drive the second one-way clutching element of the second speed-change assembly to idle with respect to the output shell, and the motor assembly is also operable to rotate in the forward direction to drive the second one-way clutching element of the second speed-change assembly to drive the output shell to rotate in the forward direction and to drive the first one-way clutching element of the first speed-change assembly to idle with respect to the output shell, wherein the two-stage speed-change output device is operable to switch for two-stage speed change in driving the output shell in a same direction with rotations of the motor assembly in the forward and backward directions;
• and wherein the motor assembly comprises an input sleeve rotatably mounted on the main axle, an electromagnetic mechanism that is excitable through energization being mounted on one end of the input sleeve, wherein the input sleeve is driven, by means of the electromagnetic mechanism being energized and excited, to rotate in one of the forward direction and backward direction relative to the main axle, and wherein the motor assembly comprises an external motor housing arranged on the main axle at an outer side of the electromagnetic mechanism, and the motor assembly further comprises an internal motor housing that is arranged at an inner side of the electromagnetic mechanism and is combined with the external motor housing, an axle seat being fit in a center of the internal motor housing and rotatably mounted on the input sleeve.