EP-4741664-A1 - FLUID PUMP WITH IMPROVED DRIVE COOLING

EP4741664A1EP 4741664 A1EP4741664 A1EP 4741664A1EP-4741664-A1

Abstract

The invention relates to a fluid pump with an electric drive unit (2) and a fluid pump module (3), wherein the electric drive unit (2) is coupled to the fluid pump module (3) for driving the fluid pump module (3), wherein an interior space (8) of the drive unit (2) is fluidically connected to a pump chamber (4) of the fluid pump module (3), so that during operation of the fluid pump (1), the fluid (16) to be pumped acts as a cooling medium (10) for the drive unit (2) and flows through the interior space (8) of the drive unit (2) along at least one flow path (SP), wherein an end (13) of a rotor (6) of an electric motor (7) arranged in the electric drive unit (2), facing away from the pump module (3) in an axial direction (A), is provided with blades (14) which form an end-side blading (15) of the rotor (6).

Inventors

NICKEL, CONRAD
HERRLING, Luis
WEINERT, HEIDEMARIE
RICHLICH, Constantin

Assignees

NIDEC GPM GmbH

Dates

Publication Date: 20260513
Application Date: 20251023

Claims (15)

Fluid pump with an electric drive unit (2) and a fluid pump module (3), wherein the electric drive unit (2) is coupled to the fluid pump module (3) for driving the fluid pump module (3), wherein an interior space (8) of the drive unit (2) is fluidically connected to a pump chamber (4) of the fluid pump module (3), such that during operation of the fluid pump (1), the fluid (16) to be pumped acts as a cooling medium (10) for the drive unit (2) and flows through the interior space (8) of the drive unit (2) along at least one flow path (SP). characterized by the fact that an end (13) of a rotor (6) of an electric motor (7) arranged in the electric drive unit (2) which is viewed in an axial direction (A) away from the pump module (3) is provided with blades (14) which form an end blading (15) of the rotor (6).
Fluid pump according to claim 1, characterized in that an electronic module (12) is arranged axially opposite the end (13) of the rotor (6) in the interior (8) of the drive unit (2), wherein in particular assembly components (12C) of the electronic module (12) point towards the end (13) of the rotor (6).
Fluid pump according to claim 1 or 2 characterized in that overflow openings (30) are provided for the fluidic connection of the interior (8) of the drive unit (2) with the pump chamber (4) of the fluid pump module (3), which open at one end into an overpressure area (UB) of the pump chamber (4) of the fluid pump module (2) and at the other end into the interior (8) of the drive unit (2).
Fluid pump according to claim 3, characterized in that the overflow openings (30) are aligned parallel to the axial direction (A) or obliquely to the axial direction (A), wherein in the case of an oblique alignment at least one pump chamber-side end of the overflow openings (30) is arranged pointing towards a fluid flow arriving locally in the inlet area.
Fluid pump according to one of claims 1 to 4, characterized in that return flow openings (32) are provided for the fluidic connection of the interior (8) of the drive unit (2) with the pump chamber (4) of the fluid pump module (2), which open into an area on the pump room side that has a lower pressure compared to the overpressure area (UB) of the pump room (4).
Fluid pump according to claim 5, characterized in that the return flow openings (32) are formed by a flow-through combination bearing (31), which is designed as a rolling bearing.
Fluid pump according to one of the preceding claims, characterized in that the blades (14) of the end blading (15) of the rotor (6) are arranged radially to an axis of rotation (RA) of the rotor (6), which extends along the axial direction (A).
Fluid pump according to one of the preceding claims, characterized in that the blades (14) of the end blading (15) of the rotor (6) are arranged at an angle to a radial direction (R).
Fluid pump according to one of the preceding claims, characterized in that the rotor (6) of the electric motor (7) has return flow channels (35) which open at one end at the end (13) of the rotor (6) facing away from the pump module (2) into an area between the end (13) of the rotor (6) facing away from the pump module (2) and the electronic module (12) and communicate fluidically with the return flow openings (32) at the other end.
Fluid pump according to one of the preceding claims, characterized in that a gap (33) between the rotor (6) and a stator (10) surrounding the rotor (6) forms a first inlet channel of the flow path (SP).
Fluid pump according to one of the preceding claims, characterized in that an outer circumferential surface of the stator (10) together with an inner surface of a drive housing (9) forms at least one further inlet channel of the flow path (SP), wherein the at least one further inlet channel runs parallel to the axial direction (A) or oblique to the axial direction (A) or helically along the outer circumferential surface of the stator (10).
Fluid pump according to one of the preceding claims, characterized in that the fluid pump (1) comprises a second flow channel which is separated from the interior (8) of the drive unit (2) and opens at one end into an overpressure area (UB) of the pump chamber (4), preferably behind a pump impeller (5) of the pump module (2), and at the other end into an ambient area around a a heat-stressed component, for example of an electronic module (12), so that the electronic module (12) and/or component parts (12C) of the electronic module (12) can be directly exposed to flow.
Fluid pump according to one of the preceding claims, characterized in that the blades (14) of the blading (15) are formed by webs or by a ramp pattern extending along a circumferential direction (U).
Fluid pump according to one of the preceding claims, characterized in that the assembly of the electronic module (12) with assembly components (12C) of the electronic module (12) is adapted to a ring flow (40) superimposed or pronounced by the blading (15) of the rotor (6).
Fluid pump according to one of the preceding claims, characterized in that the entire interior (8) of the drive unit (2) is filled with fluid (16), so that both the stator (6) and the rotor (10) of the electric motor (7) as well as the electronic module (12) are completely wetted with fluid except for their contact surfaces on adjacent components.

Description

The invention relates to a fluid pump according to the preamble of claim 1. A fluid pump of this type is made from the DE 10 2018 104 770 A1 known. Such a fluid pump has proven its worth, however, there remains a need to improve heat dissipation from electronic components of a pump control, with the aim of minimizing or eliminating any loss of efficiency. These problems are solved with a fluid pump having the features of claim 1; advantageous embodiments are specified in the dependent claims. A fluid pump according to the invention has an electric drive unit and at least one fluid pump module, wherein the electric drive unit is coupled to the fluid pump module for driving the fluid pump module, wherein an interior space of the drive unit is fluidically connected to a pump chamber of the fluid pump module, so that during operation of the fluid pump, the fluid to be pumped acts as a cooling medium for the drive unit and flows through the interior space of the drive unit along at least one flow path SP. wherein an end of a rotor of an electric motor arranged in the electric drive unit, viewed in an axial direction A away from the pump module, is provided with blades which form an end blading of the rotor. With such a fluid pump, it is possible to generate a relatively strong annular flow of the fluid located inside the drive unit in the area between the far end of the rotor and an electronic module arranged axially behind it. This results in direct flushing of components located on the electronic module, thus improving heat dissipation generated in the electronic module components. The rotor blades ensure a free-flowing annular flow, so that the components of the electronic module are actively flushed. The blades thus provide a local increase in flow velocity, but are not responsible for the fluid located inside the drive unit being pumped—as described below—from a fluid inlet to a Fluid return is transported. Such a general transport of the fluid through the interior of the drive unit is ensured by a pressure difference between an inlet and an outlet from the interior, i.e., by an external pressure gradient. It can be advantageous to arrange an electronics module axially opposite the end of the rotor in the interior of the drive unit, with the components of the electronics module in particular pointing towards the end of the rotor. With such an arrangement, it is possible to direct the ring flow of the fluid generated by the rotor together with the blading inside the drive unit as directly as possible past the heat-generating or heat-emitting components of the electronic module, thus ensuring a high heat transfer. Furthermore, it is advantageous that overflow openings are provided for the fluidic connection of the interior of the drive unit with the pump chamber of the fluid pump module, which open at one end into a pressure area of the pump chamber of the fluid pump module and at the other end into the interior of the drive unit. This measure makes it convenient to use a pressure gradient within the pump chamber to ensure a flow through the interior of the drive unit without additional pumping or conveying equipment for the fluid to be pumped within the drive unit. For the design of the overflow openings, it may be advantageous for the overflow openings to be aligned parallel to the axial direction (A) or obliquely to the axial direction (A), wherein in the case of an oblique alignment at least one pump-room-side end of the overflow openings is arranged to point towards a fluid flow arriving locally in the inlet area. In the case of a parallel alignment to the axial direction A, it is advantageous that the production of such overflow openings is particularly simple, for example by drilling parallel to the axial direction A. In the case of an oblique arrangement of the overflow openings, a slightly higher manufacturing effort is required for the overflow openings, but the flow of fluid into the interior of the drive unit can be facilitated, since a smaller angular deflection of the fluid from the pump chamber is necessary to pass through the overflow openings. To return applied fluid from the interior of the drive unit, it may be advantageous to have return flow openings for the fluidic connection between the interior of the drive unit and the pump chamber of the fluid pump module, which open on the pump chamber side into an area that has a lower pressure compared to the overpressure area of the pump chamber. This measure ensures a reliable flow through the drive unit. A particularly simple provision of return flow openings can be achieved by forming the return flow openings through a combined bearing through which the flow passes, for example, as a rolling bearing. One possible arrangement variant of the blades at the end of the rotor can be designed such that the blades of the end blading of the rotor are arranged radially to a rotation axis RA of the rotor, which extends along the axial direction A. An al