Motor centrifugal pump having coolant pump

1. A motorized centrifugal pump having a coolant pump that is driven by an electric motor, that circulates the coolant of the electric motor, and whose impeller is driven by the electric motor wherein the impeller shaft of the coolant pump is connected via a transmission to the motor shaft.

2. The motorized centrifugal pump according to claim 1 , wherein the coolant pump is a radial centrifugal pump.

3. The motorized centrifugal pump according to claim 1 wherein the transmission between motor shaft and the impeller shaft of the coolant pump is a bevel gear pair or a belt drive.

4. The motorized centrifugal pump according to claim 1 wherein a housing wall in which the coolant pump is mounted is provided between the motor housing and the housing of the centrifugal pump or a further housing wall.

5. The motorized centrifugal pump according to claim 4 wherein the coolant pump is inserted in a formfitting way in a chamber of the housing wall.

6. The motorized centrifugal pump according to claim 5 , wherein the chamber is externally closed by a cover.

7. The motorized centrifugal pump according to claim 6 , wherein an inner side of the cover forms a side of a spiral chamber of the coolant pump.

8. The motorized centrifugal pump according to claim 1 wherein the pump spiral chamber of the coolant pump has a spiral passage that is situated laterally to the impeller.

9. The motorized centrifugal pump according to claim 4 wherein the coolant pump is externally removable and insertable.

10. The motorized centrifugal pump according to claim 4 wherein the housing wall is removably fastened on the motor housing and on the pump housing or on a further housing wall.

11. The motorized centrifugal pump according to claim 1 wherein to achieve a higher speed of the coolant pump than the motorized centrifugal pump, the transmission between the motor shaft and the impeller wheel of the coolant pump has a transmission ratio of 1:2 to 1:3.

12. The motorized centrifugal pump according to claim 1 wherein an impeller axis of the coolant pump is essentially perpendicular to the motor axis.

13. A pump drive comprising:

a motor housing;

a stator in the housing;

a rotor in the housing having a shaft extending along a rotor axis, the housing being formed with a coolant passage;

a coolant pump mounted on the housing and having an impeller in the passage; and

a transmission connecting the impeller to the rotor for rotation of the impeller by the rotor.

14. The pump drive defined in claim 13 wherein the coolant pump is an axial-input/radial output pump and the impeller rotates about an impeller axis substantially perpendicular to the rotor axis.

15. The pump drive defined in claim 14 wherein the transmission is a pair of bevel gears, one of the gears being mounted on the impeller and rotatable therewith about the impeller axis, the other of the gears being mounted on the rotor and rotatable therewith about the rotor axis.

16. The pump drive defined in claim 13 wherein the housing is formed with a seat open radially outward relative to the rotor axis, the pump having a pump housing fitting generally complementarily in the seat, the impeller being journaled in the pump housing.

17. The pump drive defined in claim 16 wherein the pump housing is releasably secured in the seat.

18. The pump drive defined in claim 13 wherein the transmission is a step-up transmission from the rotor to the impeller and has a ratio of between 1:2 and 1:3.

19. The pump drive defined in claim 14 wherein the passage extends at least partially as a spiral relative to the rotor axis.

20. The pump drive defined in claim wherein the motor housing has an end plate in which the spiral is formed and that is securable to a centrifugal pump.