The pump unit has a pump and a hybrid drive. The pump comprises a pump housing and a pump shaft. The hybrid drive comprises an electric motor and a driveshaft connection to a driveshaft. The electric motor and the driveshaft connection are each in driving mechanical functional connection with the pump shaft by way of a planetary gearset for driving the pump shaft. A stator of the electric motor is at least partially integrated in the pump housing. A rotor of the electric motor is mechanically connected fixed to a sun gear of the planetary gearset. The driveshaft connection is mechanically connected fixed to a ring gear of the planetary gearset. The pump shaft is mechanically connected fixed to a planetary carrier of the planetary gearset.