DE102018220462A1 - Electrically driven machine, in particular a pump - Google Patents

Abstract

The invention relates to an electrically driven machine, in particular a pump, with an electric motor, which comprises a rotor (4) which is arranged on a rotor shaft (7) and can be rotated in a stator, which has a stator housing body (16) made of a plastic material (17). is overmolded, and with two bearings (13) to support the rotor shaft (7) with the rotor axially and radially. To improve the design of the electrically driven machine, in particular with regard to an undesirably long tolerance chain in the rotor shaft bearing, the Rotor shaft (7) with a radial-axial slide bearing (20) is mounted radially and axially both in the direction of a rotating machine element (8) and in the opposite axial direction.

Description

The invention relates to an electrically driven machine, in particular a pump, with an electric motor which comprises a rotor which is arranged on a rotor shaft and 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 disclosure WO 2012/156360 A1 An electric motor, in particular an external rotor motor for driving a fan, with a stator, with a rotor and with a slide bearing for a shaft of the rotor, is known, the slide bearing having a bearing element formed from a plastic with at least one sliding surface which is relatively movable with a Mating sliding surface is paired, for the mounting of the shaft of the rotor in a bearing support tube plain bearings with bearing elements made of plastic are provided, wherein 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 the German published application DE 10 2011 121 935 A1 an electrical machine is known with a rotor which is connected to a shaft or axle which is rotatably mounted in a bearing and with a stator which is arranged together with a bearing bush in an injection molded plastic housing.

The object of the invention is to provide 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 to support 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 to be supported axially and radially with the rotor, in that the rotor shaft is supported radially and axially with a radial-axial slide bearing both in the direction of a rotating machine element and 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. The pump is designed, for example, 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. Analogously 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 sliding 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 created in a simple manner. The bearing bush of the radial-axial sliding bearing is advantageously also formed from a plastic material, but preferably from a different plastic material than the stator housing body. The plastic material for the bearing bush 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 a view 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 slide bearing has at least one form-fitting geometry feature which ensures stable axial anchoring of the bearing bush 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 integrally connected to the stator housing body. The form-fitting geometry feature comprises, for example, a substantially annular disk-like rib which projects radially outward from the bearing bush of the radial-axial plain bearing. The bearing bush of the radial-axial sliding bearing particularly preferably comprises two such ribs. If the rib or the ribs is or are encapsulated with the plastic material, then axial relative 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 sliding bearing has at least one form-fitting geometry feature which ensures that the bearing bush is non-rotatably anchored in the stator housing body. The form-fitting geometry feature for the rotationally fixed anchoring of the bearing bush in the stator housing body comprises, for example, a rectangular recess in at least one of the ribs described above. In this way, undesired twisting of the bearing bush in the stator housing body can be prevented in a simple manner.

Another preferred exemplary embodiment of the electrically driven machine is characterized in that the bearing bush of the radial-axial sliding 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 bush is axially supported . The machine element bush is also referred to as a pump element bush if 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, in particular pump element bushing, is firmly connected to the machine element, in particular the pump element. 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 mounted only 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 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 a 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.

• 1 eine als Impellerpumpe ausgeführte elektrisch angetriebene Maschine mit einer Rotorwelle, die mit einem Radial-Axial-Gleitlager radial und axial gelagert ist, im Längsschnitt;
• 2 einen vergrößerten Ausschnitt aus 1 mit dem Radial-Axial-Gleitlager; und
• 3 eine perspektivische Darstellung einer Doppelbundbuchse des Radial-Axial-Gleitlagers aus den 1 und 2.

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

• 1 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;
• 2nd an enlarged section 1 with the radial-axial plain bearing; and
• 3rd a perspective view of a double collar bushing of the radial-axial sliding bearing from the 1 and 2nd .

In 1 is an electrically driven machine 1 shown in longitudinal section. The electrically powered machine 1 is designed as an electrically driven pump, especially a water pump. The electrically driven pump 1 includes an electric motor 3rd by a pump controller 2nd is controlled. The pump 1 is preferably designed as an electrically driven water pump.

The electric motor 3rd includes a rotor 4th that is around an axis of rotation 5 rotatable in a stator 6 is arranged. The rotor 4th is relative to the fixed stator 6 with the help of a rotor shaft 7 around the axis of rotation 5 rotatable in a pump housing 10th stored. The rotor shaft 7 of the electric motor 3rd is driving, in 1 at its left end, with a machine element 8th connected.

With the machine element 8th it is preferably a pump element, in particular an impeller 9 , the electrically driven pump 1 , which is also known as an impeller pump. The pump housing 10th includes a pump housing body 11 who in 1 right to accommodate the pump control 2nd serves. A corresponding space for the pump control 2nd in the pump housing body 11 is through a housing cover 12 locked.

The pump housing body 11 is designed as a heat sink and is advantageously made of a highly conductive, metallic material for this purpose. In the pump housing body 11 is a plain bearing 13 for an in 1 right end of the rotor shaft 7 arranged. The plain bearing 13 is designed as a floating bearing. The floating bearing includes a radial bearing bush 14 , with which the in 1 right end of the rotor shaft 7 is only mounted radially.

The stator 6 of the electric motor 3rd is in a stator housing 15 arranged. The stator housing 15 includes a stator housing body 16 made of a plastic material 17th with which the stator 6 is encapsulated. The stator 6 comprises a stator laminated core that extends in the axial direction between two rotor disks 18th , 19th is arranged. The rotor disks 18th , 19th are together with the rotor 4th rotatably with the rotor shaft 7 connected. In 1 left of the stator 6 is the rotor shaft 7 in a radial-axial plain bearing 20th stored.

In 2nd is the radial-axial plain bearing 20th for the rotor shaft 7 shown in an enlarged section. The radial-axial plain bearing 20th includes a bearing bush 21st with two axial contact surfaces facing away from each other 22 , 23 . The axial contact surface 22 is a machine element bush 24th , in particular a pump element socket 24th , facing.

The pump element socket 24th is as a collar bushing with a collar 25th executed in the axial direction on the axial contact surface 22 of the radial-axial plain bearing 20th is supported. The pump element socket 24th is formed, for example, from a preferably hardened steel material and onto the rotor shaft 7 , which is preferably also formed from a steel material, pressed on. This will make the pump element bushing 24th non-positively with the rotor shaft 7 connected.

In the 2nd right axial contact surface 23 of the radial-axial plain bearing 20th is the rotor disc 18th of the rotor 4th facing. The rotor disc 18th of the rotor 4th is in the axial direction 2nd to the left on the axial contact surface 23 of the radial-axial plain bearing 20th supported.

From a synopsis of 2nd and 3rd it follows that the radial-axial plain bearing 20th a double collar socket 26 with a first camp collar 27th and a second warehouse 28 includes. On the first camp 27th is the axial contact surface 23 for the rotor disc 18th arranged. On the second camp 28 is the axial contact surface 22 for the federal government 25th the pump element bushing 24th arranged.

The double collar socket 26 includes between the first bearing collar 27th and the second camp 28 a total of four interlocking geometry features 31 to 34 . With the form fit geometry features 31 , 32 it is an annular disk-like ribs that radially from a substantially circular cylindrical jacket-shaped base body of the double collar bushing 26 stand out.

The ribs are in the axial direction 31 , 32 evenly from each other and from the first bearing collar 27th and the second camp 28 spaced. In 2nd you can see that the double collar bushing 26 by overmolding the ribs 31 , 32 with the plastic material 17th stable in the axial direction in the stator housing body 16 is anchored.

The form-fitting geometry features 33 , 34 are advantageous with the form-fitting geometry features 31 , 32 combined. The form-fitting geometry features 33 , 34 are essentially rectangular recesses radially outside in the ribs 31 , 32 executed. By overmolding or spraying out the rectangular recesses 33 , 34 with the plastic material 17th will the Double collar socket 26 rotatably in the stator housing body 16 anchored.

In 3rd you can also see that in the axial contact surface 22 a total of three radial depressions 36 to 38 are provided. The wells 36 to 38 allow the passage of cooling and / or lubricating medium in the radial direction. In this way, lubricant and / or cooling medium advantageously passes between the rotor shaft in the radial direction from the outside inwards 7 and the double collar socket 26 . In the axial contact surface 23 the double collar bushing 26 analog recesses are provided, but in 3rd are not visible.

Reference symbol list

1

Machine, especially pump

2nd

Pump control

3rd

Electric motor

4th

rotor

5

Axis of rotation

6

stator

7

Rotor shaft

8th

Machine element, in particular pump element

9

Impeller

10th

Pump housing

11

Pump housing body

12

Housing cover

13

bearings

14

Radial bearing bush

15

Stator housing

16

Stator housing body

17th

Plastic material

18th

Rotor disc

19th

Rotor disc

20th

Radial-axial plain bearings

21st

Bearing bush

22

Contact area

23

Contact area

24th

Machine element bushing, in particular pump element bushing

25th

Federation

26

Double collar socket

27th

first camp

28

second camp

31

Form fit geometry feature

32

Form fit geometry feature

33

Form fit geometry feature

34

Form fit geometry feature

36

deepening

37

deepening

38

deepening

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 202011100921 U1 [0002]
• WO 2012/156360 A1 [0002]
• DE 102011121935 A1 [0002]

Claims (10)

Electrically driven machine (1), in particular a pump, with an electric motor (3) which comprises a rotor (4) which is arranged on a rotor shaft (7) and which can be rotated in a stator (6) which has a stator housing body (16) a plastic material (17) is overmolded, 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 -Gleitlager (20) is mounted radially and axially both in the direction of a rotating machine element (8) and in the opposite axial direction. Electric powered machine after 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. Electric powered machine after Claim 2 , characterized in that the bearing bush (21) of the radial-axial sliding bearing (20) together with the stator (6) is overmolded with the stator housing body (16) from the plastic material (17). Electric powered machine after Claim 3 , characterized in that the bearing bush (21) of the radial-axial sliding bearing (20) has at least one form-fitting geometry feature (31, 32) which ensures stable axial anchoring of the bearing bush (21) in the stator housing body (16). Electric powered machine after Claim 3 or 4th , 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 ensures that the bearing bush (21) is non-rotatably anchored in the stator housing body (16). Electrically powered machine according to one of the 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) is executed, on which a machine element bush (24) is axially supported. Electric powered machine after 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 radially extending recess (36-38) which allow the passage of a cooling and / or lubricating medium. Electric powered machine after 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). Electrically driven machine according to one of the preceding claims, characterized in that the rotor shaft (7) is mounted only radially on a side of the rotor (4) facing away from the radial-axial sliding bearing (20) in a floating bearing (13). 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 previous claims.

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