Electric motor pump

1 . An electric motor-driven pump comprising:

a pump housing that has a suction region and an outlet region and also delimits or forms a pump chamber into which the suction region and the outlet region open,

wherein a first path for a delivery flow leads through the suction region, the pump chamber and the outlet region, so that fluid can flow through the suction region, the pump chamber and the outlet region,

wherein a hollow rotor axle defining a center axis and axially penetrated by a rotor channel is arranged in the pump chamber, as well as a pump impeller mounted on the hollow rotor axle, adjustable in rotation about the center axis and drivable by an electric drive motor, for pumping fluid,

wherein the electric motor-driven pump has a cooling circuit which is open to the pump chamber and which is formed by the rotor channel, a bypass channel which fluidically connects the pump chamber with the rotor channel, and a fluid distributor channel system, which fluidically connects the rotor channel with the pump chamber,

wherein a second path for a cooling flow of fluid leads through the open cooling circuit, so that the bypass channel and the rotor channel serve to cool the electric drive motor arranged in a motor region of the pump housing for driving the pump impeller in rotation, and the fluid distributor channel system can be flowed through by fluid,

wherein the fluid distributor channel system is set up to introduce the cooling flow of fluid flowing through the open cooling circuit during operation of the electric motor-driven pump, which is branched off from the delivery flow, into the pump chamber in an inflow direction which is different from an axial direction parallel to the center axis;

wherein the rotor channel opens out at an axial end face of the hollow rotor axle, which axial end face is arranged in the pump chamber, forming an overflow opening;

wherein a holding device for the hollow rotor axle is arranged in the pump chamber, which holding device lies opposite an inflow side of the pump impeller facing the suction region and has a receptacle in which the hollow rotor axle is received together with the overflow opening;

wherein the holding device has at least one distributor channel that forms the fluid distributor channel system;

wherein the pump impeller has a plain bearing ring and the holding device has a counter plain bearing ring; and

wherein the pump impeller is supported by the counter plain bearing ring of the holding device and/or the hollow rotor axle via the plain bearing ring axially and/or radially with respect to the center axis.

2 . The electric motor-driven pump according to claim 1 , wherein the inflow direction is radial with respect to the center axis.

3 . The electric motor-driven pump according to claim 1 , wherein the inflow direction is perpendicular to a flow direction of the cooling flow within the rotor channel.

4 . The electric motor-driven pump according to claim 2 , wherein the inflow direction is perpendicular to a flow direction of the cooling flow within the rotor channel.

5 . The electric motor-driven pump according to claim 1 , wherein the inflow direction is aligned parallel or essentially parallel with respect to a flow direction of the delivery flow.

6 . The electric motor-driven pump according to claim 1 , wherein the fluid distributor channel system is designed to introduce the cooling flow into a low-pressure section of the pump chamber, which is arranged axially between the inflow side of the pump impeller and the suction region.

7 . The electric motor-driven pump according to claim 1 , wherein the at least one distributor channel passes through the holding device in the inflow direction starting from an inner surface of the receptacle of the holding device up to a lateral surface of the holding device facing the pump chamber.

8 . The electric motor-driven pump according to claim 1 , wherein:

at least one additional distributor channel is provided, and

the distributor channels are rotationally-symmetrical with respect to the center axis.

9 . The electric motor-driven pump according to claim 7 , wherein:

at least one additional distributor channel is provided, and

the distributor channels are rotationally-symmetrical with respect to the center axis.

10 . The electric motor-driven pump according to claim 1 , wherein the holding device has support arms securing the holding device to a wall of the pump chamber.

11 . The electric motor-driven pump according to claim 7 , wherein the holding device has support arms securing the holding device to a wall of the pump chamber.

12 . The electric motor-driven pump according to claim 8 , wherein the holding device has support arms securing the holding device to a wall of the pump chamber.

13 . The electric motor-driven pump according to claim 1 , wherein the at least one distributor channel of the holding device is arranged completely on a side of the counter plain bearing ring pointing away from the plain bearing ring with respect to the axial direction.

14 . The electric motor-driven pump according to claim 1 , wherein the holding device has a conical body arranged coaxially with respect to the center axis, the conical body having a cone tip facing the suction region and a cone base defining the receptacle of the holding device that provides an insertion opening for the hollow rotor axle.

15 . An electric motor-driven pump comprising:

a pump housing defining a suction region, an outlet region, and a pump chamber in fluid communication with the suction region and the outlet region, wherein a delivery flow path extends through the suction region, the pump chamber, and the outlet region;

an electric motor arranged in a motor region of the pump housing;

a hollow rotor axle arranged in the pump chamber, the hollow rotor axle defining a center axis and having a rotor channel extending axially therethrough;

a pump impeller rotatably mounted on the hollow rotor axle and driven by the electric motor to pump fluid along the delivery flow path;

a holding device for the hollow rotor axle arranged in the pump chamber opposite an inflow side of the pump impeller; and

an open cooling circuit comprising the rotor channel, a bypass channel connecting the pump chamber to the rotor channel, and a fluid distributor channel system connecting the rotor channel to the pump chamber,

wherein a cooling flow path extends through the open cooling circuit for a cooling fluid branched from the delivery flow path to cool the electric motor,

wherein the fluid distributor channel system is configured to introduce the cooling fluid from the cooling circuit into the pump chamber in an inflow direction that is different from an axial direction parallel to the center axis, and

wherein the pump impeller comprises a plain bearing ring and the holding device comprises a counter plain bearing ring, the pump impeller being supported axially or radially relative to the center axis by at least one of the counter plain bearing ring and the hollow rotor axle via the plain bearing ring.

16 . The electric motor-driven pump according to claim 15 , wherein the fluid distributor channel system comprises at least one distributor channel extending through the holding device in the inflow direction from an inner surface of a receptacle of the holding device to a lateral surface of the holding device facing the pump chamber.

17 . The electric motor-driven pump according to claim 15 , wherein the holding device comprises support arms securing the holding device to a wall of the pump chamber.

18 . The electric motor-driven pump according to claim 15 , wherein the fluid distributor channel system comprises at least one distributor channel arranged entirely on a side of the counter plain bearing ring.

19 . The electric motor-driven pump according to claim 18 , wherein the holding device comprises a conical body arranged coaxially with respect to the center axis, the conical body having a cone tip facing the suction region and a cone base defining a receptacle of the holding device that provides an insertion opening for the hollow rotor axle.

20 . The electric motor-driven pump according to claim 15 , wherein the fluid distributor channel system comprises a plurality of distributor channels arranged in rotational-symmetry with respect to the center axis.