Motor-pump unit
A motor-pump unit, in particular for a power steering system of a motor vehicle, comprises a housing, a pump, and a drive motor. The pump is constructed as a prefabricated pump module. Both the pump module and the motor are received directly in the housing.
1. A motor-pump unit, comprising:
a housing including a surrounding side wall and having a first open end and a second open end, the first open end defining a pump space, the second open end defining a motor space which also serves as a hydraulic fluid reservoir, the housing further including an intermediate wall disposed between the pump space and the motor space;
a pump module disposed in the pump space of the housing, the pump module including a pump body separate from the housing and containing pump components, and a pump cover closing the pump body;
wherein an outer surface of the pump body and an inner surface of the side wall of the housing cooperate to define a resonator space, the pump module having an inlet sucking hydraulic fluid from the hydraulic fluid reservoir and having an outlet for supplying pressurized fluid to the resonator space;
a resonator cover separate from the pump cover connected to the first open end of the housing and closing and sealing the resonator space;
a drive motor received directly in the motor space of the housing and connected through the intermediate wall of the housing to drive the pump module; and
a plate connected to the second open end of the housing and closing and sealing the motor space.
2. The motor-pump unit according to claim 1 , wherein the plate is a carrier plate separate ftom the housing and has power electronics components arranged on a surface thereof.
3. The motor-pump unit according to claim 1 , wherein the resonator cover is constructed as a flat punched part.
4. The motor-pump unit according to claim 1 , wherein the resonator space is formed substantially by a bell-shaped resonator cover which is mounted on the housing.
5. The motor-pump unit according to claim 4 , wherein the bell-shaped resonator cover is constructed as one of a diecast and a deep-drawn part.
6. The motor-pump unit according to claim 1 , wherein the housing is constructed in one piece as a diecast part.
7. The motor-pump unit according to claim 1 , wherein the housing is fonned from diecast and deep-drawn parts.
8. The motor-pump unit according to claim 1 , wherein the drive motor is immersed in the hydraulic fluid in the motor space of the housing.
9. The motor-pump unit according to claim 1 , wherein the resonator space is filled with hydraulic fluid which surrounds the pump module.
10. The motor-pump unit according to claim 1 , wherein hydraulic fluid pressure within the resonator space urges the pump module toward the intermediate wall of the housing.
11. The motor-pump unit according to claim 1 , wherein the resonator space acts to reduce pulsations generated by the pump module, thereby reducing noise.
12. The motor-pump unit according to claim 2 , wherein the power electronics components are arranged on a side of the carrier plate facing away from the motor space.
13. The motor-pump unit according to claim 2 , wherein heat generated by the power electronics components is transferred through the carrier plate to the hydraulic fluid in the motor space.
14. The motor-pump unit according to claim 1 , further including a combined pressure control and non-return valve installed in the resonator cover.
15. The motor-pump unit according to claim 1 , further including a hydraulic fluid reservoir arranged around the resonator space, the hydraulic fluid reservoir providing fluid volume equalization.