Power takeoff, gearbox and vehicle

The utility model provides a power takeoff, a gearbox and a vehicle, the power takeoff is used for the gearbox, and the power takeoff comprises a shell, an air cylinder cover, a piston, a gear shifting assembly, a first sealing ring and a second sealing ring; the air cylinder cover is connected with the shell and provided with an air port and a cavity, and the air port is communicated with the cavity. The piston is arranged in the cavity; the gear shifting assembly comprises a push rod. One end of the push rod faces the piston. The first sealing ring is arranged on the piston in a sleeving mode and makes contact with the inner wall of the cavity; the second sealing ring is arranged on the piston in a sleeving mode, located on one side of the first sealing ring and makes contact with the inner wall of the cavity. According to the power takeoff, the piston is sleeved with the first sealing ring and the second sealing ring, double sealing is achieved through the first sealing ring and thesecond sealing ring, the