Pump device comprising a radial bearing

Abstract

A pump device, in particular for a fluid circuit in a motor vehicle, comprising a housing, a drive, a rotor, a stator and a radial bearing, wherein the housing has an inlet, wherein the rotor comprises an impeller wheel, wherein the drive is designed to set the rotor in rotation relative to the stator, wherein the inlet is fluidly connected to the impeller wheel, wherein the rotor has a rotor cavity, wherein a section of the stator projects into the rotor cavity, and wherein the radial bearing is situated in the rotor cavity between the section of the stator and the rotor.

Claims

1. A pump for a fluid circuit in a motor vehicle, the pump comprising: a housing; a rotor; a stator; and a radial bearing, wherein the housing has an inlet, wherein the rotor comprises an impeller wheel, wherein the rotor rotates relative to the stator about a longitudinal axis, wherein the inlet is fluidly connected to the impeller wheel, wherein the rotor has a rotor cavity that extends along the longitudinal axis, wherein a section of the stator projects into the rotor cavity, wherein, with respect to a radial direction of the longitudinal axis, the radial bearing is situated in the rotor cavity between the section of the stator and the rotor, such that an inner circumferential surface of the section of the stator is positioned closer to the longitudinal axis than an inner circumferential surface of the radial bearing, and wherein the radial bearing has a first bearing region, a second bearing region and a third bearing region, wherein in the first bearing region, a first outer surface of the radial bearing has a first outer diameter and in the second bearing region, a second outer surface of the radial bearing has a second outer diameter that is smaller than the first outer diameter, and wherein the third bearing region connects the first bearing region to the second bearing region, such that the third bearing region has a sloped outer surface that extends from the first outer surface having the first outer diameter to the second outer surface having second outer diameter that is smaller than the first outer diameter.

2. The pump according to claim 1, wherein the stator has a stator cavity, wherein the stator cavity is surrounded by the section of the stator, and wherein the stator cavity is fluidly connected to the rotor cavity.

3. The pump according to claim 2, wherein the stator cavity and/or the rotor cavity are free of a shaft.

4. The pump according to claim 2, wherein the pump comprises a vent outlet, wherein the vent outlet is fluidly connected to the rotor cavity so that air flows from the stator cavity through the rotor cavity to the vent outlet.

5. The pump according to claim 1, wherein the section of the stator projects into the rotor cavity at a first end of the rotor, wherein the impeller wheel is disposed at a second end of the rotor, and wherein the second end is disposed opposite the first end.

6. The pump according to claim 1, wherein the section of the stator has a first region and a second region, wherein the section of the stator has a third outer diameter in the first region and a fourth outer diameter in the second region, and wherein the fourth outer diameter is smaller than the third outer diameter.

7. The pump according to claim 6, wherein the first bearing region of the radial bearing and the first region of the section of the stator partially overlap in the radial direction and wherein the second bearing region of the radial bearing and the second region of the section of the stator partially overlap in the radial direction.

8. The pump according to claim 1, wherein the pump comprises a bearing situated between the impeller wheel and the housing.

9. The pump according to claim 8, wherein the bearing axially supports the rotor.

10. The pump according to claim 9, wherein the housing has an annular groove and the impeller wheel has an annular projection which projects into the annular groove, and wherein the bearing is situated between the annular projection and the housing.

11. The pump according to claim 8, wherein the bearing radially supports the rotor.

12. The pump according to claim 11, wherein the bearing has an L-shaped cross-sectional area.

13. The pump according to claim 1, wherein the pump comprises an outlet, wherein the impeller wheel causes a fluid flow from the inlet to the outlet when the rotor rotates.

14. A motor vehicle, comprising the pump according to claim 1 and a fluid circuit, wherein the pump pumps a fluid in the fluid circuit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

(2) FIG. 1 shows a schematic perspective view of a pump device according to one embodiment of the invention;

(3) FIG. 2 shows a schematic sectional view of a pump device according to one embodiment of the invention; and

(4) FIG. 3 shows a schematic sectional view of a pump device according to one embodiment of the invention.

DETAILED DESCRIPTION

(5) Pump device 100 comprises a housing 101, an inlet 102, and an outlet 103. Pump device 100 is designed to be connected to a fluid circuit with inlet 102 and outlet 103. In operation, pump device 100 causes a flow of the fluid in the fluid circuit.

(6) The embodiment shown in FIG. 2 comprises an inlet 102, an outlet 103, a rotor 200 with an impeller wheel 201 and with a rotor cavity 206, a stator 202 with a section 205 and with a stator cavity 204, a radial bearing 203, and a bearing 207. Section 205 projects into rotor cavity 206. Stator cavity 204 is disposed in section 205 and is fluidly connected to rotor cavity 206. Radial bearing 203 is disposed between section 205 and rotor 200.

(7) Radial bearing 203 has a larger outer diameter in a first region than in a second region. The outer diameter of radial bearing 203 tapers continuously between the first region and the second region. This shape of radial bearing 203 is particularly advantageous for a good radial support of rotor 200. The shape is particularly advantageous for good lubrication of radial bearing 203.

(8) Bearing 207 is used for the axial support of rotor 200. The bearing is arranged in a groove of the housing between a projection of impeller wheel 201 and the housing and is formed annular. At this position, bearing 207 has little or even no effect on both the fluid flow and the ventilation flow.

(9) Stator cavity 204 and rotor cavity 206 are free of a shaft. As a result, rotor cavity 206 and stator cavity 204 can be used particularly well for venting pump device 100. The air can be routed through stator cavity 204 and rotor cavity 206 to a vent outlet through which it then exits pump device 100 into the environment.

(10) During operation, rotor 200 with impeller wheel 201 is set in rotation relative to stator 202 by a drive (not shown). In the process, a fluid, for example, a working fluid of a motor vehicle, is drawn in through inlet 102 and conveyed to outlet 103 by means of impeller wheel 201. The air displaced thereby flows through stator cavity 204 and rotor cavity 206 to a vent outlet.

(11) The embodiment shown in FIG. 3 differs from the embodiment shown in FIG. 2, among other things, in the shape of radial bearing 303 and in the shape of section 305 of stator 302. Radial bearing 303 is formed annular. Consequently, section 305 therefore has a constant outer diameter. In addition, section 305 projects less far into stator 300 than in the embodiment according to FIG. 2.

(12) Instead of the annular bearing 207 from FIG. 2, the embodiment in FIG. 3 has a bearing 400 that is L-shaped in cross section. This L-shaped bearing 400 is used for both the axial and the radial support of rotor 300. Bearing 400 has in particular the advantage over bearing 207 from FIG. 2 in that the gaps between the housing and the projection of the impeller wheel 301 can be made smaller.

(13) However, the operation of the embodiment of FIG. 3 is similar to that of the embodiment of FIG. 2. The advantage of the shape of radial bearing 303 and the shorter section 305 is primarily an improved air flow during ventilation through stator cavity 304 and rotor cavity 306 as compared to the embodiment of FIG. 2.

(14) The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.