FLUID PUMP

Abstract

A fluid pump is described, in particular an oil pump for supply to a clutch actuator, a gearbox actuator, a lubrication system and/or a cooling system of a drive train, with an electrical drive unit with a stator and a rotor. The rotor is arranged inside the stator and an inner wall delimiting the stator chamber radially inwardly has at least one wall portion which engages in an assigned radial depression of the stator present between two circumferentially adjacent stator segments. Furthermore, a method for producing a fluid pump is proposed.

Claims

1. A fluid pump for supply to a clutch actuator, a gearbox actuator, a lubrication system and/or a cooling system of a drive train, with an electrical drive unit which comprises a stator and a rotor that is rotatable about a rotor axis, wherein the stator is arranged in an annular stator chamber of a drive housing, and the rotor is arranged in a rotor chamber which is separate from the stator chamber and lies inside the stator chamber, wherein an inner wall delimiting the stator chamber radially inwardly has at least one wall portion which engages in an assigned radial depression of the stator present between two circumferentially adjacent stator segments.

2. The fluid pump according to claim 1, wherein the inner wall delimiting the stator chamber radially inwardly has several circumferentially distributed wall portions, wherein each of the wall portions engages in an assigned radial depression of the stator present between circumferentially adjacent stator segments.

3. The fluid pump according to claim 1, wherein the wall portion is a radial bulge of the inner wall, or the wall portions are radial bulges of the inner wall, wherein the radial bulges extend over an entire axial length of the inner wall.

4. The fluid pump according to claim 3, wherein the radial bulge forms or the radial bulges form a corresponding radial recess or corresponding radial recesses on a side of the inner wall facing the rotor chamber.

5. The fluid pump according to claim 1, wherein a substantially axially running coolant channel is formed in each of the wall portions, in particular wherein the coolant channels are radially open in the direction of the rotor chamber.

6. The fluid pump according to claim 1, wherein the wall portion is rounded on its radial outside over its entire axial length.

7. The fluid pump according to claim 1, wherein the stator chamber and the rotor chamber are pot-like, wherein the stator chamber and the rotor chamber are open on opposite axial sides.

8. The fluid pump according to claim 1, wherein the stator is embedded in the stator chamber with a casting compound.

9. The fluid pump according to claim 1, wherein the fluid pump is an annular gear pump.

10. A method for producing a fluid pump with an electric drive unit which comprises a stator and a rotor that is rotatable about a rotor axis, said method comprising: a) providing a stator with several stator segments distributed around the circumference of the stator, wherein a radial depression is formed between respective adjacent stator segments, b) providing a drive housing with a stator chamber wherein the stator chamber has wall portions corresponding to the radial depressions and protruding relative to a base contour of an inner wall delimiting the stator chamber, c) aligning the stator relative to the drive housing such that each of the radial depressions lies opposite a corresponding wall portion in the axial direction, d) inserting the stator in the drive housing, wherein the protruding wall portions engage in the assigned radial depressions.

11. The method according to claim 9, wherein the stator is encapsulated inside the stator chamber.

Description

[0027] The invention is explained below with reference to an exemplary embodiment shown in the attached drawings. The drawings show:

[0028] FIG. 1 a fluid pump according to the invention in a perspective external view,

[0029] FIG. 2 the fluid pump from FIG. 1 in a depiction cut along an axial plane, and

[0030] FIG. 3 a detail III of the fluid pump from FIG. 2.

[0031] FIG. 1 shows a fluid pump 10 which, in the embodiment shown, is formed as an oil pump for supplying a clutch actuator.

[0032] At the same time, the fluid pump 10 is also suitable for supplying oil to a gearbox actuator, a cooling system and/or a lubrication system of a drive train.

[0033] The fluid pump 10 is designed as an annular gear pump. It thus comprises a pump unit 12 which works on the principle of an annular gear pump.

[0034] By means of the pump unit 12, fluid provided to the fluid pump 10 via a fluid inlet 14 is conveyed to a fluid outlet 16 of the fluid pump 10. The fluid is pressurised, so the fluid inlet 14 may be described as the suction side and the fluid outlet 16 as the pressure side.

[0035] The pump unit 12 is driven by means of an electric drive unit 18 which is controlled by a control unit 20.

[0036] The electric drive unit 18 is arranged between the pump unit 12 and the control unit 20.

[0037] The electric drive unit 18 furthermore comprises a stator 22 and a rotor 24, depicted merely schematically in FIG. 2 and FIG. 3, which is rotatable about a rotor axis 26.

[0038] In this context, the stator 22 is arranged in an annular stator chamber 22a of a drive housing 28, and the rotor 24 is arranged in a rotor chamber 24a which is separate from the stator chamber 22a and lies inside this. The rotor chamber 24a thus lies in the interior of the ring shape. The rotor 24 is thus a so-called internal rotor.

[0039] Also, the stator 22 is encapsulated inside the stator chamber 22a by means of a casting compound 23. In other words, the stator 22 is embedded in the stator chamber 22a by means of the casting compound 23.

[0040] Both the rotor chamber 24a and the stator chamber 22a are formed pot-like, wherein the stator chamber 22a and the rotor chamber 24a are open on opposite axial sides. This so-called double pot form is configured as part of the drive housing.

[0041] The stator 22 comprises several stator segments 22b which are distributed around its circumference. Of the total of twelve stator segments 22b present in the embodiment according to FIG. 2, for reasons of clarity only a few are marked with a reference sign.

[0042] A radial depression 22c is provided between respective adjacent stator segments 22b.

[0043] The rotor chamber 24a and the stator chamber 22a are separated by an inner wall 30.

[0044] This inner wall 30 thus delimits the stator chamber 22a radially inwardly and the rotor chamber 24a radially outwardly.

[0045] It has a number of wall portions 30a corresponding to the number of radial depressions 22c of the stator 22 and formed as radial bulges 30b in the direction of the stator 22, which form corresponding radial recesses 30c in the direction of the rotor chamber 24a.

[0046] The radial bulges 30b and radial recesses 30c extend substantially over the entire axial length of the inner wall 30.

[0047] Each of the radial bulges 30b here engages in a respective assigned radial depression 22c of the stator 22, so that the stator 22 is mounted non-rotatably in the drive housing 28. For this, the radial bulges 30b and the radial depressions 22c create a form-fit connection acting in the circumferential direction.

[0048] Also, a coolant channel 30d running substantially axially is formed in each wall portion 30a and is radially open in the direction of the rotor chamber 24a. Via the coolant channels 30d, coolant can be conducted into the rotor chamber 24a so that the electrical drive unit 18 is cooled. This applies in particular to the rotor 24.

[0049] Furthermore, the wall portions 30a are rounded at their radial outsides. In the sectional depictions of FIGS. 2 and 3, the radial outsides of the wall portions 30a thus take the form of part circles.

[0050] Thus the axially running coolant channels 30d may firstly be equipped with a comparatively large flow cross-section.

[0051] Secondly, the cooling channels 30d have a comparatively large surface area because of the rounded form of the wall portions 30a, so that a heat exchange between the coolant flowing in the cooling channels 30d and the stator chamber 22 is promoted.

[0052] The fluid pump 10 may be produced as follows.

[0053] Firstly, the stator 22 with the circumferentially distributed stator segments 22b and the radial depressions 22c lying in between is produced.

[0054] Also, the drive housing 28 is produced in which the stator chamber 22a is present.

[0055] As already explained, the stator chamber 22a is delimited radially inwardly by the inner wall 30, and the inner wall 30 has wall portions which protrude relative to a base contour. These wall portions 30a are designed as radial bulges 30a on the stator side.

[0056] Now the stator 22 is aligned relative to the drive housing 28 so that each of the radial depressions 22c along the rotor axis 26 lies opposite a corresponding wall portion 30a, i.e. a corresponding radial bulge 30b.

[0057] Then the stator is inserted into the drive housing 28 along the rotor axis 26, wherein the protruding wall portions 30a in the form of radial bulges 30b engage in the assigned radial depressions 22c.

[0058] Finally, the stator 22 is encapsulated in the stator chamber 22a by means of a casting compound 23.