Transmission and electric automobile

The invention relates to automobile machinery and discloses a transmission which comprises a box body, a power transmission device, a clutch device and a planetary gear mechanism, and the power transmission device, the clutch device and the planetary gear mechanism are arranged in the box body. A low-pressure oil cavity communicated with an oil inlet pipe and a high-pressure oil cavity communicated with an oil outlet pipe are formed in the two sides of the meshing area of the sun gear and the planetary gear and the two sides of the meshing area of the planetary gear and the planetary gear shell respectively. Mechanical friction generated by the clutch is matched with hydraulic damping generated by the high-pressure oil cavity and the low-pressure oil cavity to achieve a good speed change effect, abrasion of gear pieces and ablation of the clutch are avoided, the service life of the transmission is prolonged, the structure is simple, and the production cost can be reduced. In addition, the invention further re