WO2020108711A1

WO2020108711A1 - Electrically driven machine, in particular a pump

Info

Publication number: WO2020108711A1
Application number: PCT/DE2019/200137
Authority: WO
Inventors: Jan Hinrichs; Said Jennaoui; Antonia Schlosshan; Michael Krug
Original assignee: Hanon Systems Efp Deutschland Gmbh
Priority date: 2018-11-28
Filing date: 2019-11-25
Publication date: 2020-06-04
Also published as: DE102018220462A1

Abstract

The invention relates to an electrically driven machine, in particular a pump, having an electric motor, which comprises a rotor (4) that is arranged on a rotor shaft (7) and is rotatable in a stator, which stator is overmolded with a stator housing body (16) made of a plastics material (17), and having two bearings (13) in order to axially and radially support the rotor shaft (7) together with the rotor. In order to improve the design of the electrically driven machine, in particular in respect of an undesirably long tolerance chain in the bearing arrangement for the rotor shaft, the rotor shaft (7) is supported radially and axially by a radial-axial sliding bearing (20) in the direction of a rotating machine element (8) and also in the opposite axial direction.

Description

Electrically powered machine, especially a pump

The invention relates to an electrically driven machine, in particular a pump, with an electric motor, which comprises a rotor arranged on a rotor shaft, which is rotatable in a stator, which is extrusion-coated with a stator housing body made of a plastic material, and with two bearings around the rotor shaft to store the rotor axially and radially.

From the German utility model DE 20 2011 100 921 U1 and the international publication WO 2012/156360 A1 an electric motor, in particular an external fan motor for driving a fan, with a stator, with a rotor and with a sliding bearing for a shaft of the rotor is known , wherein the plain bearing has a gebil det plastic bearing element with at least one sliding surface which is relatively movable paired with a counter sliding surface, with tube bearings are provided with bearing elements made of plastic for mounting the shaft of the rotor in a bearing support, at least one Bearing element can be formed by an integral part of the stator or a stator bushing or can be molded onto the stator or the stator bushing. From German published patent application DE 10 2011 121 935 A1, an electrical machine with a rotor is known, which is connected to a shaft or axis, which is rotatably mounted in a bearing, and with a stator, which together with a bearing bush in an injection-molded housing is arranged from plastic.

The object of the invention is to provide an electrically driven machine, in particular a pump, with an electric motor which comprises a rotor which is arranged on a rotor shaft and can be rotated in a stator, which is extrusion-coated with a stator housing body made of a plastic material, and with two bearings to store the rotor shaft with the rotor axially and radially, constructively, especially with regard to an undesirably long tolerance chain in the rotor shaft bearing, to improve.

The object is in an electrically driven machine, in particular a pump, with an electric motor which comprises a rotor arranged on a rotor shaft, which is rotatable in a stator, which is extrusion-coated with a stator housing body made of a plastic material, and with two bearings around the rotor shaft with the rotor axially and radially, thereby solves that the rotor shaft with a radial-axial plain bearing both radially and axially in the direction of a rotating machine element as well as in the opposite axial direction. The electrically driven machine is designed in particular as an electrically driven pump. Then the rotating machine element is preferably a rotating pump element, such as an impeller. For example, the pump is designed as a water pump and is also referred to as an impeller pump with the impeller. The stator housing body can be made in one part or in several parts. The stator can be completely or partially extrusion-coated with the plastic material. The term axial refers to an axis of rotation of the rotor of the electrically driven machine. Axial means in the direction or parallel to the axis of rotation of the rotor of the electrically driven machine. Ana log means radially transverse to the axis of rotation of the rotor of the electrically driven machine.

A preferred exemplary embodiment of the electrically driven machine is characterized in that the radial-axial slide bearing comprises a bearing bush with two axial contact surfaces facing away from one another. This can be produced inexpensively and provides the advantage that a second axial bearing for the rotor shaft can be dispensed with. In addition, a shorter tolerance chain can be realized in this way in order to support the rotor shaft with less axial play.

Another preferred exemplary embodiment of the electrically driven machine is characterized in that the bearing bush of the radial-axial sliding bearing is extrusion-coated from the plastic material together with the stator with the stator housing body. In this way, a cast-in fixed bearing with axial run-up on both sides is easily created. The bearing bush of the radial-axial sliding bearing is advantageously also made from a plastic material, but preferably from a different plastic material than the stator housing body. The plastic material for the bearing sleeve of the radial-axial plain bearing is advantageously selected with regard to its tribological properties. The plastic material for the stator housing body is advantageously selected with regard to high stability and elasticity.

Another preferred exemplary embodiment of the electrically driven machine is characterized in that the bearing bush of the radial-axial sliding bearing has at least one form-fitting geometry feature which ensures stable axial anchoring of the bearing bushes in the stator housing body. Since the bearing bush of the radial-axial sliding bearing and the stator housing body are formed from different materials, in particular from different plastic materials, it can happen that the bearing bush of the radial-axial sliding bearing is not or not completely cohesively connected to the stator housing. The form-fitting geometry feature comprises, for example, a substantially annular disk-like rib that extends radially outward from the bearing bush of the Radial-axial plain bearing protrudes. The bearing bush of the radial-axial sliding bearing particularly preferably comprises two such ribs. If the rib or the ribs is extrusion-coated with the plastic material, then relative axial movements between the bearing bush and the stator housing body are excluded.

Another preferred exemplary embodiment of the electrically driven machine is characterized in that the bearing bush of the radial-axial slide bearing has at least one form-fitting geometry feature which ensures that the bearing bush is anchored in the stator housing body in a rotationally fixed manner. The form-fitting geometry feature for the rotationally fixed anchoring of the bearing bush in the stator housing body comprises, for example, a right-angled recess in at least one of the ribs described above. In this way, unwanted twisting of the bearing bush in the stator housing body can be prevented in a simple manner.

A further preferred exemplary embodiment of the electrically driven machine is characterized in that the bearing bush of the radial-axial slide bearing is designed as a double collar bushing with a first bearing collar on which the rotor is axially supported and a second bearing collar on which a machine element bushing is axially arranged supports. The Ma machine element bush is also referred to as a pump element bush when the electrically driven machine is designed as an electrically driven pump. The first bearing collar of the double collar bushing is advantageously axially supported on a rotor disk of the rotor. The rotor disk is formed, for example, from a metallic material. The rotor disk of the rotor is advantageously formed from a steel material. The machine element bushing, in particular the pump element bushing, is advantageously also formed from a metallic material, for example a steel material.

A further preferred exemplary embodiment of the electrically driven machine is characterized in that the first and the second bearing collar of the double collar bushing each have at least one radially extending depression, which allow the passage of a cooling and / or lubricating medium. The cooling and / or lubricating medium can also be a working medium of the machine, in particular a pump. The working medium of the machine, in particular the pump, is in particular water or oil. The water or oil is not used in its pure form, but preferably with approximately fifty percent of a synthetic additive that is intended to prevent freezing.

Another preferred exemplary embodiment of the electrically driven machine is characterized in that the machine element bushing is designed as a collar bushing with a collar which is axially supported on the second bearing collar of the double collar bushing. The machine element bushing, especially the pump element bushing, is firmly attached to the machine nenelement, in particular the pump element connected. The machine element bush with the machine element, in particular the pump element bush with the pump element, is in turn firmly connected to the rotor shaft. The fixed connection between the machine element bush and the rotor shaft is realized, for example, by a press fit.

Another preferred exemplary embodiment of the electrically driven machine is characterized in that the rotor shaft is only supported radially in a floating bearing on a side of the rotor facing away from the radial-axial sliding bearing. The floating bearing is advantageously designed as a second sliding bearing, but in contrast to the radial-axial sliding bearing, the second sliding bearing has no axial contact surface. The floating bearing is advantageously designed as a pure radial bearing. The floating bearing comprises, for example, a machine element bush, in particular a pump element bush, which is pressed into a heat sink of a control housing.

The invention further relates to a radial-axial sliding bearing, a bearing bush, in particular re a double collar bushing, a bearing arrangement and / or a stator, in particular a stator housing body, for a previously described electrically driven machine, in particular special pump. The parts mentioned can be traded separately.

The invention optionally also relates to a method for producing and / or assembling a machine, in particular a pump, as described above.

The invention optionally also relates to a tool for producing a previously described machine, in particular a pump, or a previously described bearing bush, in particular a double collar bushing.

Further advantages, features and details of the invention will become apparent from the following description, in which various exemplary embodiments are described in detail with reference to the drawing. Show it:

1 shows an electrically driven machine designed as an impeller pump with a rotor shaft which is mounted radially and axially with a radial-axial slide bearing, in longitudinal section;

FIG. 2 shows an enlarged detail from FIG. 1 with the radial-axial sliding bearing; and

FIG. 3 shows a perspective illustration of a double collar bushing of the radial-axial sliding bearing from FIGS. 1 and 2.

In Figure 1, an electrically driven machine 1 is shown in longitudinal section. The electrically driven machine 1 is designed as an electrically driven pump, in particular a water pump. The electrically driven pump 1 comprises an electric motor 3, which is controlled by a pump controller 2. The pump 1 is preferably designed as an electrically driven water pump.

The electric motor 3 comprises a rotor 4 which is arranged in a stator 6 so as to be rotatable about an axis of rotation 5. The rotor 4 is mounted relative to the fixed stator 6 by means of a rotor shaft 7 rotatable about the axis of rotation 5 in a pump housing 10. The rotor shaft 7 of the electric motor 3 is connected in terms of drive, in Figure 1 at its left end, to a machine element 8.

The machine element 8 is preferably a pump element, in particular an impeller 9, the electrically driven pump 1, which is also referred to as an impeller pump. The pump housing 10 comprises a pump housing body 11, which is used on the right in FIG. 1 to accommodate the pump control 2. A corresponding receiving space for the pump control 2 in the pump housing body 11 is closed by a housing cover 12.

The pump housing body 11 is designed as a heat sink and is advantageously formed for this purpose from a highly conductive, metallic material. In the pump housing body 11, a slide bearing 13 is arranged for a right end of the rotor shaft 7 in FIG. 1. The sliding bearing 13 is designed as a floating bearing. The floating bearing comprises a radial bearing bush 14 with which the right end of the rotor shaft 7 in FIG. 1 is only supported radially.

The stator 6 of the electric motor 3 is arranged in a stator housing 15. The stator housing 15 comprises a stator housing body 16 made of a plastic material 17, with which the stator 6 is extrusion-coated. The stator 6 comprises a laminated stator core which is arranged in the axial direction between two rotor disks 18, 19. The rotor disks 18, 19 are rotatably connected to the rotor shaft 7 together with the rotor 4. In Figure 1 to the left of the stator 6, the rotor shaft 7 is mounted in a radial-axial slide bearing 20.

In Figure 2, the radial-axial sliding bearing 20 for the rotor shaft 7 is shown in an enlarged section. The radial-axial sliding bearing 20 comprises a bearing bush 21 with two axial thrust surfaces 22, 23 facing away from one another. The axial thrust surface 22 faces a machine element bushing 24, in particular a pump element bushing 24.

The pump element bushing 24 is designed as a collar bushing with a collar 25 which is supported in the axial direction on the axial contact surface 22 of the radial-axial sliding bearing 20. The pump element bushing 24 is formed, for example, from a preferably hardened steel material and onto the rotor shaft 7, which is preferably also made from a steel material. det is pressed. As a result, the pump element bushing 24 is non-positively connected to the rotor shaft 7.

The right axial contact surface 23 of the radial-axial sliding bearing 20 in FIG. 2 faces the rotor disk 18 of the rotor 4. The rotor disk 18 of the rotor 4 is supported in the axial direction in FIG. 2 to the left on the axial contact surface 23 of the radial-axial sliding bearing 20.

A summary of FIGS. 2 and 3 shows that the radial-axial sliding bearing 20 comprises a double collar bushing 26 with a first bearing collar 27 and a second bearing collar 28. The axial contact surface 23 for the rotor disk 18 is arranged on the first bearing collar 27. The axial bearing surface 22 for the collar 25 of the pump element bush 24 is arranged on the second bearing collar 28.

Between the first bearing collar 27 and the second bearing collar 28, the double collar bushing 26 comprises a total of four interlocking geometry features 31 to 34. The interlocking geometry features 31, 32 are annular disk-like ribs which protrude radially from an essentially circular-cylindrical jacket body of the double collar bushing 26.

In the axial direction, the ribs 31, 32 are evenly spaced from one another and from the first bearing collar 27 and the second bearing collar 28. In FIG. 2 it can be seen that the double bushing 26 is stably anchored in the stator housing body 16 in the axial direction by the extrusion coating of the ribs 31, 32 with the plastic material 17.

The interlocking geometry features 33, 34 are advantageously combined with the interlocking geometry features 31, 32. The form-fitting geometry features 33, 34 are designed as essentially rectangular recesses radially outside in the ribs 31, 32. The double collar bushing 26 is anchored non-rotatably in the stator housing body 16 by extrusion-coating or injection-molding the rectangular recesses 33, 34 with the plastic material 17.

FIG. 3 also shows that a total of three radial depressions 36 to 38 are provided in the axial contact surface 22. The depressions 36 to 38 allow the passage of cooling and / or lubricating medium in the radial direction. Lubricant and / or cooling medium advantageously reaches in the radial direction from the outside inwards between the rotor shaft 7 and the double collar bushing 26. Analog recesses are provided in the axial contact surface 23 of the double collar bushing 26, but are not visible in FIG. 3. Reference list

Machine, especially pump

Pump control

Electric motor

rotor

Axis of rotation

stator

Rotor shaft

Machine element, in particular pump element

Impeller

Pump housing

Pump housing body

Housing cover

bearings

Radial bearing bush

Stator housing

Stator housing body

Plastic material

Rotor disc

Radial-axial plain bearings

Bearing bush

Contact area

Machine element bushing, in particular pump element bushing collar

Double collar socket

first camp second camp

Form fit geometry feature Form fit geometry feature Form fit geometry feature Form fit geometry feature recess

deepening

Claims

1. Electrically driven machine (1), in particular a pump, with an electric motor (3), which comprises a rotor (4) arranged on a rotor shaft (7), which can be rotated in a stator (6), which is connected to a stator housing body ( 16) is overmolded from a plastic material (17), and with two bearings (20; 13) to support the rotor shaft (7) with the rotor (3) axially and radially, characterized in that the rotor shaft (7) with a Radial-axial plain bearing (20) is mounted radially and axially both in the direction of a rotating machine element (8) and in the opposite axial direction.

2. Electrically driven machine according to claim 1, characterized in that the radial-axial sliding bearing (20) comprises a bearing bush (21) with two axial contact surfaces (22, 23) facing away from one another.

3. Electrically driven machine according to claim 2, characterized in that the La gerbüchse (21) of the radial-axial sliding bearing (20) together with the stator (6) with the stator housing body (16) is overmolded from the plastic material (17).

4. Electrically driven machine according to claim 3, characterized in that the La gerbüchse (21) of the radial-axial sliding bearing (20) has at least one form-fitting geometry feature (31, 32) that a stable axial anchoring of the bearing bush (21) in the stator housing body (16) ensures.

5. Electrically driven machine according to claim 3 or 4, characterized in that the bearing bush (21) of the radial-axial sliding bearing (20) has at least one form-fitting geometry feature (33, 34) which has a rotationally fixed anchoring of the bearing bush (21) in the stator housing body (16) ensures.

6. Electrically driven machine according to one of claims 2 to 5, characterized in that the bearing bush (21) of the radial-axial sliding bearing (20) as a double collar bushing (26) with a first bearing collar (27) on which the rotor (4) is axially supported, and a second bearing collar (28) on which a machine element bush (24) is axially supported.

7. Electrically driven machine according to claim 6, characterized in that the first and the second bearing collar (27, 28) of the double collar bushing (26) each have at least one radial have running recess (36-38) that allow the passage of a cooling and / or lubricating medium.

8. Electrically driven machine according to claim 6 or 7, characterized in that the machine element bushing (24) is designed as a collar bushing with a collar (25) which is axially supported on the second bearing collar (28) of the double collar bushing (26).

9. Electrically driven machine according to one of the preceding claims, characterized in that the rotor shaft (7) on a side facing away from the radial-axial sliding bearing (20) of the rotor (4) in a floating bearing (13) is only supported radially.

10. Radial-axial sliding bearing (20), bearing bush (21), in particular double collar bushing (26), bearing arrangement and / or stator (6), in particular stator housing body (16), for an electrically driven machine (1), in particular a pump, according to one of the preceding claims.