Supply unit with overpressure relief valve

A rotor (15) is arranged in a pump chamber (14) delimited by an intake cap and a discharge cap. A pressure chamber (35) is arranged upstream of the pump chamber. A pressure relief valve (70) is arranged on the intake cap, and can close or open the flow connection from the pressure chamber to the pump chamber upstream. The flow connection from the pressure chamber to the pressure relief valve leads directly through the pump chamber.