Pump unit with conical motor chamber

A pump unit for pressurising a hydraulic actuating system, wherein the pump unit comprises:

• a hydraulic pump, and a pump housing including a pump chamber for housing the hydraulic pump;
• an electric motor for driving the hydraulic pump and a motor housing including a motor chamber for housing the electric motor;
• and
• a reservoir in fluid communication with the hydraulic pump for containing a hydraulic fluid;
• wherein the electric motor comprises:
• a motor rotor, wherein the motor rotor comprises a motor rotor body;
• a plurality of field coils;
• and
• a plurality of magnets which are disposed opposite the field coils for rotationally driving the motor rotor body;
• wherein a clearance is provided in between an inner circumferential surface of the motor chamber and an outer circumferential surface of the motor rotor body,
• wherein the clearance is diverging in the axial direction from a small diameter to a large diameter, and
• wherein a fluid outlet is provided at a position of the large diameter of the clearance, such that in operation of the pump unit a hydraulic fluid in the clearance is caused to flow towards the fluid outlet to exit the motor chamber.