Fluid pump having an internal bearing collar and method for assembling the fluid pump

Abstract

An electric fluid pump may include a pump housing and an electric motor. A rotor may have a rotor shaft and may be mounted in a rotatable manner in a stator body, which may have a stator embedded at least regionally therein. The pump housing may be subdivided into a dry and a wet region containing the rotor. The rotor shaft may be mounted on a bottom side and may be connected to a pump impeller on a pump-impeller side, facing away from the bottom side. The pump housing may have, on the pump-impeller side, an aperture out of which the rotor shaft may project. The pump housing may have an internal first bearing collar arranged around the aperture, the dry region located radially around the first bearing collar, and an outside diameter of the first bearing collar being less than a maximum diameter of the rotor.

Claims

1. An electric fluid pump comprising: a pump housing; and an electric motor arranged in the pump housing; wherein a rotor of the electric motor has a rotor shaft and is mounted in a rotatable manner in a stator body, which has a stator embedded in the stator body; wherein the pump housing is subdivided into a dry region and into a wet region containing the rotor; wherein the rotor shaft is mounted on a bottom side in the pump housing and is connected in terms of drive to a pump impeller on a pump-impeller side, facing away from the bottom side, of the pump housing; wherein the pump housing has, on the pump-impeller side, an aperture out of which the rotor shaft projects; wherein the pump housing has an internal first bearing collar arranged around the aperture, wherein the dry region is located radially around the first bearing collar, and wherein an outside diameter of the first bearing collar is less than a maximum diameter of the rotor; wherein the stator body has a fixing collar having a fixing collar radially inner facing surface and a seal between a radially outer facing surface of the first bearing collar and the fixing collar radially inner facing surface, the stator body being fixed to the first bearing collar; and wherein the first bearing collar has at least one fluid duct passing axially along a radially inner facing surface of the first bearing collar and radially external to the aperture, which leads toward the outside out of the wet region of the pump housing to the pump impeller.

2. The fluid pump according to claim 1, wherein the first bearing collar is formed integrally on the pump housing, and a first shaft bearing receiving the rotor shaft is arranged in a manner butting against an inner face of the first bearing collar.

3. The fluid pump according to claim 1, wherein at least one fluid duct is arranged in the first bearing collar, said fluid duct leading axially towards an outside from the wet region.

4. The fluid pump according to claim 1, wherein the pump housing has a cylindrical housing bottom part encasing the stator body, wherein a diameter of the cylindrical housing bottom part is greater than a spacing between the bottom side and the pump-impeller side of the pump housing.

5. The fluid pump according to claim 1, further comprising a controller clamped in the pump housing in such a manner that a fixing opening is around the fixing collar of the stator body and perpendicular to the rotor shaft.

6. The fluid pump according to claim 5, wherein the first bearing collar passes through the fixing opening.

7. The fluid pump according to claim 5, wherein a diameter of the fixing opening is independent of an inside diameter of the stator body and the maximum diameter of the rotor.

8. The fluid pump according to claim 5, wherein the stator body has a plurality of integrally formed clamping ribs, which are formed around the fixing collar and on which the controller is arranged in a supported manner.

9. The fluid pump according to claim 5, wherein the controller includes a control board.

10. The fluid pump according to claim 9, wherein the controller has an electronic component fixed to the control board, the electronic component passing through the control board through a component opening in the control board.

11. The fluid pump according to claim 9, wherein the control board is fixed in the pump housing.

12. A fluid pump according to claim 1, wherein the pump housing has a second bearing collar, which is formed integrally on the bottom side of the pump housing in a manner facing away from the first bearing collar, wherein a second shaft bearing receiving the rotor shaft is arranged in a manner butting against an inner face of the second bearing collar.

13. A fluid pump according to claim 12, wherein the second bearing collar is arranged around a press opening in the pump housing, wherein the press opening is closable with a housing plug.

14. The fluid pump according to claim 1, wherein: the stator body is formed from a thermally conductive plastic such that when a voltage that is too high relative to a speed of the electric motor is applied to the stator, any excess power that is generated is able to be emitted as a heat output to a fluid to be pumped, via the stator body.

15. A fluid pump according to claim 1, wherein the seal is a sealing ring encircling the first bearing collar.

16. A method for assembling a fluid pump, comprising: arranging a rotor shaft, a rotor and a stator body of an electric motor in a housing bottom part of a pump housing subdivided into a dry region and a wet region; arranging a controller arranged on a fixing collar of the stator body; and fixing a housing cover to the housing bottom part; wherein the rotor shaft is mounted on a bottom side in the pump housing and is connected in terms of drive to a pump impeller on a pump-impeller side, facing away from the bottom side, of the pump housing; wherein the pump housing has, on the pump-impeller side, an aperture out of which the rotor shaft projects; wherein the pump housing has an internal first bearing collar arranged around the aperture, wherein the dry region is located radially around the first bearing collar, and wherein an outside diameter of the first bearing collar is less than a maximum diameter of the rotor; wherein the fixing collar includes having a fixing collar radially inner facing surface and a seal between a radially outer facing surface of the first bearing collar and the fixing collar radially inner facing surface, the stator body being fixed to the first bearing collar; and wherein the first bearing collar has at least one fluid duct passing axially along a radially inner facing surface of the first bearing collar and radially external to the aperture, which leads toward the outside out of the wet region of the pump housing to the pump impeller.

17. The method according to claim 16, further comprising: pressing a first shaft bearing into the first bearing collar in the housing cover before the housing bottom part is closed with the housing cover; and pressing a second shaft bearing into a second bearing collar before the rotor shaft and the rotor are arranged in the housing bottom part.

18. The method according to claim 16, further comprising interconnecting the controller with a stator embedded in the stator body after the controller has been arranged on the fixing collar of the stator body.

19. The method according to claim 16, further comprising arranging the rotor shaft and the rotor in the stator body before arranging the rotor shaft, the rotor and the stator body in the housing bottom part.

20. The method of claim 16, further comprising forming the stator body from a thermally conductive plastic via one of a single-stage plastic overmoulding process or a multistage plastic overmoulding process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings, in each case schematically

(2) FIG. 1 shows a sectional view of a fluid pump according to the invention with a pump impeller;

(3) FIG. 2 shows a sectional view of the fluid pump according to the invention with a pump impeller and with an alternatively designed control board; and

(4) FIGS. 3 to 6 show individual steps in a method according to the invention for assembling the fluid pump shown in FIG. 1.

DETAILED DESCRIPTION

(5) FIG. 1 shows a sectional view of an electric fluid pump 1 according to the invention. The fluid pump 1 has a pump housing 2 and an electric motor 3 arranged in the pump housing 2. The pump housing 2 is in this case formed by a housing bottom part 2a and a housing cover 2b. A rotor 4 having permanent magnets 5 is fixed to a rotor shaft 6 for conjoint rotation and is mounted in a stator body 7 having an embedded stator 8 so as to be rotatable about an axis of rotation 6a. The stator 8 has a plurality of coils 9 and further electrical components, which are embedded in the stator body and are surrounded by a material of the stator body 7—for example plastic. In this way, the coils 9 and the further electrical components of the stator 8 can be protected from a fluid to be pumped. The stator body 8 is encased by the regionally cylindrical housing bottom part 2a, such that the heat generated in the stator body 7 can be emitted towards the outside. The housing bottom part 2a can, to this end, consist for example of aluminium.

(6) The pump housing 2 is subdivided into a dry region 10 and into a wet region 11, wherein a control board 12 is arranged in the dry region 10 and the rotor 4 is arranged in the wet region 11. The rotor shaft 6 is mounted on a bottom side 13 in the pump housing 2 and is connected in terms of drive to a pump impeller 15 on a pump-impeller side 14, facing away from the bottom side 13, of the pump housing 2. In this exemplary embodiment, the rotor shaft 6 is configured in a hollow manner and can be flowed through and cooled by the fluid to be pumped. A spacing ABP of the bottom side 13 from the pump-impeller side 14 of the pump housing 2 is furthermore less than a diameter DB of the pump housing 2. The spacing ABP and the diameter DB are measured on the outside in this exemplary embodiment, but can alternatively also be measured on the inside.

(7) The pump housing 2 has, on the pump-impeller side 14, an aperture 16, out of which the rotor shaft 6 with the pump impeller 15 projects. The pump housing 2 has a first bearing collar 17, which is formed integrally inside the pump housing 2, around the aperture 16. Arranged on an inner face 17a of the first bearing collar 17 is a first shaft bearing 18, which receives the rotor shaft 6. A diameter DD of the aperture 16 and an inside diameter IDL of the first bearing collar 17 are thus determined by the rotor shaft 6 and the shaft bearing 18, and are independent of a maximum diameter MDR of the rotor 4 and an inside diameter IDS of the stator body 7.

(8) Furthermore, the dry region 10 is located radially around the first bearing collar 17, and the housing cover 2b axially separates the wet region 11 from a pump-impeller wet region 19. In order to connect the wet region 11 and the pump-impeller wet region 19 in a fluid-conducting manner, the first bearing collar 17 has fluid ducts 20, which lead towards the outside, out of the wet region 11 of the pump housing 2, to the pump impeller 15. An outside diameter ADL of the bearing collar 17 is accordingly determined by the inside diameter IDL of the bearing collar 17 and the fluid ducts 20, and is independent of the maximum diameter MDR of the rotor 4 and the inside diameter IDS of the stator body 7. The outside diameter ADL of the bearing collar 17 is less than the maximum diameter MDR of the rotor and the dry region 10 around the rotor shaft 6 is advantageously enlarged.

(9) The stator body 7 furthermore has a fixing collar 21, which butts against an outer face 17b of the first bearing collar 17. The fixing collar 21 and the first bearing collar 17 thus separate the dry region 10 from the wet region 11 around the rotor shaft 6. Arranged between the first bearing collar 17 and the fixing collar 21, and between the stator body 7 and the housing bottom part 2a, is a respective sealing ring 22, and the dry region 10 is sealed off thereby. The control board 12 is arranged around the fixing collar 21 of the stator body 7 with a fixing opening 23 and is clamped between clamping ribs 21a of the fixing collar 21 and the housing cover 2b. The dry region 10 is arranged radially around the first bearing collar 17 and the control board 12 with the fixing opening 23 is fixed in the pump housing 2 in a space-saving manner. The outside diameter ADL of the first bearing collar 17 is independent of the maximum diameter MDR of the rotor 4 and of the inside diameter IDS of the stator body 7 and remains constant with differently designed rotors and stator bodies. Accordingly, the dimensions of the fixing collar 21 and a diameter DF of the fixing opening 23 also remain constant. Advantageously, an identically configured control board 12 can be installed in fluid pumps 1 with varying rotors 4 and stator bodies 7 and as a result the product costs and the production effort can be considerably reduced.

(10) The rotor shaft 6 is mounted in the pump housing 2 on the bottom side 13 in a second bearing collar 24. To this end, a second shaft bearing 25 that receives the rotor shaft 6 is fixed to an inner face 24a of the second bearing collar 24. The rotor shaft 6 is thus supported on the pump-impeller side 14 by the first shaft bearing 18 and on the bottom side 13 by the second shaft bearing 25. The fluid pump 1 is thus modular and connectable to differently designed pump impellers 15. In order to make it easier to mount the rotor shaft 6 in the second shaft bearing 25, the second bearing collar 24 is formed around a press opening 26 in the pump housing 2. When the rotor shaft 6 is being mounted in the second shaft bearing 25, an opposing pressure can be built up through the press opening 26 and damage to the rotor shaft 6 can be avoided. A housing plug 27 seals the pump housing 2 off towards the outside at the press opening 26.

(11) Overall, in the fluid pump 1 according to the invention, the dry region 10 is enlarged compared with a conventional fluid pump and there is more installation space available for the control board 12. In the fluid pump 1 according to the invention, it is furthermore possible for the dimensions of the rotor 4 and of the stator body 7 to be adapted to the power requirements without changing the control board 12. Advantageously, the fluid pump 1 according to the invention can be operated in a modular manner with differently designed pump impellers 15.

(12) FIG. 2 shows a sectional view of the fluid pump 1 according to the invention with the alternatively designed control board 12. Here, an electronic component 32—in this case a capacitor 33—is fixed to the control board, said electronic component 32 passing through the control board 12 through a component opening 34. As a result, the electronic component 32 can be cooled better and the fluid pump 1 can be designed in a more compact manner overall. Otherwise, the fluid pump 1 shown here corresponds to the fluid pump in FIG. 1.

(13) FIG. 3 to FIG. 6 show individual steps in a method 28 according to the invention for assembling the fluid pump 1 shown in FIG. 1. As shown in FIG. 3, first of all the second shaft bearing 25, the rotor 4 with the rotor shaft 6, and the stator body 7 are arranged in the housing bottom part 2a. On the stator body 7, the control board 12 is arranged with the fixing opening 23 around the fixing collar 21 and in a manner supported on the clamping ribs 21a. The control board 12 is subsequently fixed to the housing bottom part 2a with screws 29 or optionally with rivets. In the case of a pump housing 2 made of plastic, staking is also conceivable for fixing the control board 12. As shown in FIG. 4, the control board 12 is subsequently interconnected with the stator 8 by means of a tool 30. In the housing cover 2b, the first shaft bearing 18 and the sealing ring are arranged on the first bearing collar 17, as shown in FIG. 5. In FIG. 6, the housing cover 2b is subsequently arranged on the housing bottom part 2a and fixed by screws 31.