CN109937524B

CN109937524B - Electric machine

Info

Publication number: CN109937524B
Application number: CN201780070985.7A
Authority: CN
Inventors: L.巴凯; J.贝内克; P.昂格瓦里; N.苏奇
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2016-11-16
Filing date: 2017-10-25
Publication date: 2021-11-09
Anticipated expiration: 2037-10-25
Also published as: WO2018091242A1; DE102016222563A1; CN109937524A

Abstract

The invention relates to an electric machine (10), in particular for controlling moving parts in a motor vehicle, comprising a commutator (55) arranged on a rotor shaft (20), which commutator can be connected to an electrical power source in an electrically conductive manner by means of brushes (26), wherein the brushes (26) are electrically connected to a contact element (16) arranged at an axial end of a pole housing (12) accommodating a stator (13), wherein a plug element (18) having a connection pin (42) for the brushes (26) is arranged on the contact element (16), wherein at least one electronic interference suppression element (60) is arranged in the plug element (18) and is located radially outside the pole housing (12).

Description

Electric machine

Technical Field

The invention relates to an electric machine having an electric motor and a gear mechanism which can be driven by the electric motor and which is arranged in a gear mechanism housing, wherein the electric motor has an associated motor housing and can be connected in an electrically conductive manner for the purpose of current supply by means of a connection plug which is connected to a brush holder.

Background

Electric motor drives are known from the prior art, which can be used, for example, to drive seat adjusters, window lifters and/or wipers in motor vehicles. These electric motor drives have an electric motor which is arranged in a motor housing and is operatively connected to a gear mechanism arranged in a gear mechanism housing, wherein the motor housing and the gear mechanism housing are fastened to one another, for example screwed or riveted to one another. The motor current required for operation can be supplied to the electric motor via a plug.

DE102010062727 a1 discloses a brush holder component of an electric motor drive, which is arranged axially between the electric motor and a transmission housing. A plug for current supply is arranged radially on the brush holder component. On the annular base body of the brush holder component, various electronic components are fastened, such as, for example, sensor components or interference-suppression components that improve EMV radiation. Such a brush holder component, although being made compact with all the electronic components arranged thereon, is not sufficiently EMV-compatible for the particular application.

Disclosure of Invention

In contrast, the invention proposes an electric machine having a commutator arranged on a rotor shaft, which commutator can be connected in an electrically conductive manner to a power supply by means of brushes, wherein the brushes are electrically connected to a contact element arranged at an axial end of a pole housing accommodating a stator, wherein a plug element having a connection pin for the brushes is arranged on the contact element, characterized in that at least one electronic interference suppression element is arranged in the plug element, which is radially outside the pole housing, wherein the connection pin is electrically connected to the brushes by means of conductor tracks and the at least one interference suppression element is in electrical contact with the conductor tracks, and wherein the conductor tracks are designed as stamped bent parts which are inserted into the contact element or are injection-molded with the contact element, and wherein all electronic components of the electric machine, except for the at least one interference suppression element, are arranged directly on the contact member and the electric machine has no electronic circuit board, and wherein the interference suppression element has a varistor which is arranged together with a capacitor inside a common housing, and wherein the housing is designed as a ceramic from which a connection leg for making electrical contact with the interference suppression element protrudes, and wherein the connection leg is welded or soldered to the printed conductor for making electrical contact with the interference suppression element. The electric machine according to the invention has the following advantages, namely: the interference suppression element is arranged at a distance from the brushes bearing against the commutator by being arranged radially outside the motor housing. By fixing the interference suppression element inside the plug member connected to the contact member, the interference suppression element can be connected to the conductor element that is required anyway with a short connecting lead. As a result, the interference suppression effect can be significantly improved without any increase in installation complexity and installation space requirements when the interference suppression element is fixed.

When the interference suppression element is arranged in the plug component, it can be connected directly to a conductor strip (leitersleifen) which is designed as a plug pin on one end and is connected to a brush on the other end. These conductor bars can advantageously be designed as stamped bent parts, to which at least one interference suppression element can be soldered or welded.

The interference suppression element is advantageously produced as a so-called SMD (Surface Mounted Device) component, on which short connecting lines are formed, which can be brought into electrical contact with the conductor tracks.

The interference suppression element preferably has a capacitor, which provides a capacitance of at least 1 μ F, for example. Such a capacitor can protect the brushes that are in contact with the collector particularly well from overvoltages.

In a particularly preferred embodiment of the invention, the varistor is also a component of the at least one interference suppression element, wherein the varistor together with the capacitor is surrounded by a common housing element with regard to the structural space and optimization of the installation process.

If the conductor bars are designed as stamped and bent parts, two such conductor bars can be inserted into the contact element, for example for two carbon brushes. According to an embodiment of the contact element, the stampings are either merely inserted into the plug element or are not yet encapsulated by the plastic material of the plug element. In this way, the at least one interference suppression element can be brought directly into electrical contact with the integrally formed stamped and bent part. In order to obtain a comparatively easy accessibility of the welding or soldering electrode when fixing the connecting wire of the at least one interference-free element, an axial contact plate is stamped out on the stamped and bent part opposite the end of the plug pin, on which contact plate an electrical contact is made with the connecting wire of the at least one interference-free element.

For mounting the electric machine, it is advantageous if the plug member is formed as one part together with the contact member, since then the plug member is arranged mechanically fixed radially outside the pole pot simultaneously with the axial mounting of the contact member on the stator. In this case, between the plug member and the contact member, which preferably has a radially extending base plate, a web extends in the radial direction between the contact member and the plug member. In this case, the conductor bars extend over their entire length in a single component, which considerably facilitates the installation of the conductor bars.

The plug pins are arranged in a circumferential plug flange which extends, for example, in an axial direction parallel to a rotor shaft of the electric motor. The plug member has a receiving space for the at least one interference-free element opposite the free end of the connection pin, which can be closed with a plug cover.

The interference suppression element can very advantageously be inserted axially into the receiving space in such a way that the connecting small leg of the interference suppression element extends in the radial direction toward the rotor axis. In this case, the small connecting leg rests against an axial contact plate of the printed conductor and can thus be electrically contacted by a welding or soldering pliers, which presses the small connecting leg against the contact plate, for example, in the circumferential direction.

The plug cover is preferably produced as a component produced separately from the plug component, and after installation closes the receiving space for the at least one tamper-resistant element for electrical contacting of the tamper-resistant element. Since the receiving space is formed, for example, by an axially extending wall of the plug flange, the receiving space is open in the axial direction. In this case, the separate plug cover can be inserted in the axial direction onto the plug component and can be securely fixed to the plug component, for example by means of a clamping or latching connection. Alternatively or additionally, the receiving space can also be cast from a plastic material, which reliably holds the interference suppression element in the plug member in place even in the presence of strong vibrations.

If the plug component together with the plug cover is located radially outside the pole housing and in particular outside an axially adjacent transmission housing, the separately designed plug cover can be placed axially onto the receiving space in a simple manner after the installation of the at least one interference suppression element.

In such an embodiment, the contact element is axially clamped between the pole housing and the gear housing, wherein the contact element has a central bore in a radially extending base plate, through which bore an armature shaft projects from the rotor into the gear housing.

The connection according to the invention of the interference-free element is particularly advantageous for motors for which no additional circuit board for electronic components is required. Thus, all necessary electronic components are arranged directly on the contact member, wherein the interference-resistant element is arranged in the plug member as far as possible from the rotor shaft. With this arrangement, an additional EMV shield is not required when necessary, thereby reducing the number of components and mounting steps.

The base plate of the contact element can be used directly for receiving brushes which can be configured either as vibrating brushes (foster bursten) or as hammer brushes. Alternatively, the brushes are arranged in separate brush elements, the brushes of which are then electrically connected with the contact member. A sensor element for detecting the rotational position of the rotor shaft may be arranged on the base plate. Also, a conductor bar in contact with the carbon brush is fixed to the base body of the contact member. This is done, for example, by means of a snap connection or by means of an injection molding with the plastic material of the contact element.

The conductor track extends radially from the base plate of the contact element via the web into the plug element and is bent there in such a way that it extends there as a connection pin in the axial direction. A separating wall extending transversely to the rotor axis is preferably arranged between the plug flange for the connection pin and the receiving space for the at least one interference-free element. The angled conductor bars pass through this separating wall, so that the contact plates for the interference-free elements are arranged in the separated receiving spaces. The circumferential wall of the receiving space can have perforations formed in the circumferential direction (tangential direction), through which welding or soldering pliers can be brought into contact with the contact plates in the tangential direction. In this embodiment, the plug cover preferably also has a circumferential wall which extends in the axial direction and, after its mounting on the plug member, covers the tangential perforations for the contact plates.

Drawings

The invention is explained in detail in the following description with the aid of embodiments illustrated in the drawings. Wherein:

FIG. 1 illustrates an overall view of an electric machine according to one embodiment; and is

Fig. 2 shows a contact member of the electric machine according to fig. 1.

Detailed Description

Fig. 1 shows an electric motor 10, such as is used, for example, for adjusting movable components in a motor vehicle, preferably window panes, a sunroof or a seat assembly. In this case, a stator 13 is arranged in the pole housing 12, inside which a rotor 15 is arranged, the rotor shaft 20 of which extends axially from the pole housing 12 into the axially adjacent gear housing 14. In this case, the drive torque is transmitted by the rotor shaft 20 to a gear mechanism arranged in the gear mechanism housing 14, which has an output element 22 that engages in a mechanical device, not shown, which moves, for example, a component of a vehicle seat or a window pane in a motor vehicle. Between the pole housing 12 and the gear housing 14, along the axial direction 24, a contact element 16 is arranged, which is connected to a brush 26 for electrical contact with a commutator arranged on the rotor shaft 20.

The brushes 26 can be designed as hammer brushes 27 or as oscillating brushes 28. The contact element 16 has a plug element 18, which is arranged radially outside the pole housing 12 and the gear housing 14 in a radial direction 23. The plug member 18 is connected to the contact member 16 by means of radial webs 30. The contact element 16 has a base body 32 radially inside the pole housing 12, which has a central recess 34 through which the rotor shaft 20 extends in the axial direction 24. The plug member 18 has a plug flange 40, in the interior of which connecting pins 42 are arranged for electrical contact with the electric machine 10. In the exemplary embodiment of fig. 1, the plug flange 40 extends with the connection pin 42 along the axial direction 24, so that a corresponding plug can likewise be inserted into the plug flange 40 along the axial direction 24. As can be seen from fig. 1, the base body 32 of the contact element 16 is axially clamped between the two

flanges

92, 94 of the pole housing 12 and the gear housing 14, wherein the outer circumferential wall 44 of the base body 32 in this exemplary embodiment at the same time forms part of the outer wall 45 of the electric machine 10. For example, the gear housing 14 is connected to the pole housing 12 by means of screws 48 or other connecting elements, whereby the contact element 16 is fixedly clamped and fixed between the pole housing 12 and the gear housing 14.

Fig. 2 shows a contact element 16, as can be mounted, for example, in the electric machine 10 according to fig. 1. The brush 26 is designed here, for example, as a hammer brush 27, which is fastened with its spring legs 29 to, for example, a separately produced brush element 17. This brush element 17 bears axially against the contact component 16 and the brush 26 is electrically connected to an electrical conductor track 50 of the contact component 16, which makes electrical contact with the connecting pin 42. Alternatively, the brush elements 17 can also be produced integrally with the contact component 16, wherein the brushes 26 can also be designed as oscillating brushes 28. The conductor track 50 is in the exemplary embodiment designed as a stamped and bent part 51, the first end 52 of which is connected to the brush 26 and the opposite end 53 of which forms the connection pin 42. In this case, the conductor tracks 50 extend radially along the radial webs 30 from the pole housing 12 into the plug element 18. A tamper-resistant element 60 is arranged in the plug component 18, which is electrically connected to the conductor tracks 50. Since in this exemplary embodiment the complete plug component 18 is arranged radially outside the pole housing 12, the interference suppression element 60 is also arranged completely radially outside the pole housing 12. The interference suppression element 60 is designed here as an SMD component (Surface Mounted Device), which is directly electrically connected to the conductor tracks 50, preferably soldered or welded together. The anti-jamming element 60 packageA capacitor 62 protects the motor 10 from overvoltages. The capacitor 62 has, for example, at least 1 muF (>10^-6F) For intercepting (abfangen) the corresponding voltage peak. The interference suppression element 60 additionally has a varistor 64, which is arranged together with the capacitor 62 inside a common housing 66. The housing 66 is, for example, designed as a ceramic part, from which small connecting legs 68 project for making electrical contact with the interference suppression element 60. For the electrical contacting of the interference suppression element 60, the small connecting legs 68 are welded or soldered to the conductor tracks 50. For a comparatively easy assembly, axial projections 70 extending in the axial direction 24 are formed on the printed conductor 50, which projections can be produced, for example, in one process step during the blanking of the printed conductor 50. In this exemplary embodiment, the conductor tracks 50 extend in the axial direction 24 in the interior of the plug flange 40 starting from their second end 53, which is designed as a connection pin 42. An intermediate wall 72 is formed inside the plug flange 40, through which the conductor tracks 50 are guided into a receiving space 74 for the interference suppression element 60. This intermediate wall 72 thus separates the connection pin 42 from the receiving space 74. Inside the receiving space 74, the conductor track 50 is bent in the radial direction 23 and extends along the radial webs 30 to the base body 32, where it contacts the brush 26. In this exemplary embodiment, the receiving space 74 can be closed by a releasable plug cover 76, which completely closes the receiving space 74 after the installation of the interference suppression element 60 has ended. The receiving space 74 has a circumferential wall 80, which is designed substantially as an axial extension of the plug flange 40 beyond the intermediate wall 72. In the circumferential wall 80, a (aussapien) opening 81 is provided through which a welding or soldering pliers (not shown) can press the small connecting leg 68 against the conductor track 50. Preferably, the axial projections 70 of the conductor tracks 50 project axially beyond the intermediate wall 72 forming the base of the receiving space 74, so thatThe small connecting leg 68 can be directly connected to the axial projection 70. After the interference suppression element 60 is electrically connected to the conductor tracks 50, the plug cover 76 is fixed to the plug component 18, for example by means of a snap connection 84. For this purpose, latching elements 85 are formed, for example, on the circumferential wall 80, which latching elements interact with mating latching elements 86 of the plug cover 76. Optionally, the receiving space 74 can also be cast in order to reliably protect the interference suppression element 60 and its electrical connections to the printed conductors 50. The interference suppression element 60 or its housing 66, viewed in the axial direction 24, has a substantially quadrangular or rectangular contour, from which the small connecting leg 68 extends in the radial direction 23 toward the radial web 30. The surrounding wall 80 of the receiving space 74 is likewise of quadrilateral or rectangular design, corresponding to the contour of the interference suppression element 60. In addition to the interference suppression element 60, no further electronic components 88 are arranged inside the plug member 18, but rather these are arranged radially inside the pole housing 12 on the base body 32 of the contact member 16. In this exemplary embodiment, the electric machine 10 has no electronic circuit board, but the electronic components 88 are fastened directly to the base body 32 of the contact element 16.

In the exemplary embodiment according to fig. 2, the plug cover 76 can also be released or locked with the plug member 18 after the transmission housing 14 has been axially connected to the pole housing 12. As a result, the interference suppression element 60 can also be installed at the end after the assembly of the electric motor with the transmission housing 14 has ended. Alternatively, the plug member 18 can also be equipped with the interference suppression element 60 before the contact member 16 is inserted into the pole housing 12. In this case, it is also possible to dispense with a releasable plug cover 76 and to encapsulate the tamper-resistant element 60 in the plug component 18, for example by injection molding. By the metallic design of the plug cover 76, an electromagnetic shielding Effect (EMV) can additionally be achieved, which prevents the following: that is, the printed conductor 50 and/or the connection pin 42 functioning as an antenna generate interfering radiation. In particular, the plug cover 76 can also be formed in one piece with an electrically conductive EMV shield, which extends radially into the pole housing 12. Such a plug cover 76 can be electrically connected to the pole housing 12 and/or the bearing of the rotor shaft 20 via an EMV shield. This enables electromagnetic interference caused by commutation to be shielded by the insulating cover (K ä fig) closed by the pole case 12.

It is to be noted that the specific shape of the pole housing 12, of the gear housing 14 and of the contact element 16 shown in the figures can be adapted to the respective application of the electric machine 10. Thus, for example, the base body 32 can accommodate different electronic components 88 as required. Likewise, the design of the conductor tracks 50 can also be varied and, for example, can be injection-molded with the contact elements 16 or clipped into the contact elements 16. Due to the spatial distance of the interference suppression element 60 from the brush 26, depending on the application, any additional EMV shielding can be dispensed with or, for example, the plug cover 76 can be provided with a metallic shielding. In an alternative embodiment, which is not shown, the plug flange 40 with the connection pins 42 can also extend in the radial direction 23 or in the tangential direction 25 relative to the rotor shaft 20. In this case, the plug component 18 with the interference suppression element 60 is always arranged radially outside the pole housing 12 and preferably also radially outside the transmission housing 14, despite the integral design with the contact component 16. Alternatively, the plug member 18 can also be produced separately and subsequently connected to the contact member 16, in particular inserted into the contact member. The interference suppression element 60 is preferably configured as a combined element having a capacitor 62 and a varistor 64.

Claims

1. Electrical machine (10) for adjusting moving parts in a motor vehicle, having a commutator (55) arranged on a rotor shaft (20), which commutator can be connected in an electrically conductive manner to a power supply by means of brushes (26), wherein the brushes (26) are electrically connected to contact elements (16) arranged at axial ends of a pole housing (12) accommodating a stator (13), wherein a plug element (18) having connection pins (42) for the brushes (26) is arranged on the contact elements (16), characterized in that at least one electronic interference suppression element (60) is arranged in the plug element (18), which is radially outside the pole housing (12), wherein the connection pins (42) are electrically connected to the brushes (26) by means of printed conductors (50), and the at least one interference-suppression element (60) is in electrical contact with the conductor tracks (50), and wherein the conductor tracks (50) are designed as stamped bent parts (51) which are inserted into the contact members (16) or are injection-molded with the contact members, and wherein, with the exception of the at least one interference-suppression element (60), all electronic components (88) of the electric machine (10) are arranged directly on the contact members (16) and the electric machine (10) has no electronic circuit board, and wherein the interference-suppression element (60) has a varistor (64) which is arranged inside a common housing (66) together with a capacitor (62), and wherein the housing (66) is designed as a ceramic part, from which a small connecting leg (68) for making electrical contact with the interference-suppression element (60) protrudes, and wherein the small connecting leg (68) is welded or soldered to the conductor track (50) for making electrical contact with the interference-free element (60).

2. The electrical machine (10) according to claim 1, characterized in that the at least one interference suppression element (60) is designed as a capacitor (62) for overvoltage protection, which has a capacitance of at least 1 μ F.

3. The electrical machine (10) according to claim 1 or 2, characterized in that an axially projecting contact plate (70) is formed on the conductor track (50) for contacting the at least one interference-resistant element (60).

4. The electrical machine (10) according to claim 1 or 2, characterized in that the contact element (16) is connected to the plug element (18) by means of a radial web (30) and is formed integrally with the plug element as a plastic injection-molded part.

5. The electrical machine (10) of claim 1 or 2, wherein the plug member (18) has: a plug flange (40) in which the connection pins (42) are arranged; and a releasable plug cover (76) which closes a receiving space (74) for the at least one tamper-resistant element (60) in the plug component (18).

6. The electrical machine (10) according to claim 5, characterized in that the connection pin (42) extends in the axial direction (24) of the rotor shaft (20), and the plug cover (76) is arranged axially opposite the connection pin (42) and covers the axially open receiving space (74).

7. The electrical machine (10) according to claim 5, characterised in that the circumferential wall (80) of the receiving space (74) is formed by an axial extension of the plug flange (40), and the plug cover (76) can be connected to the circumferential wall (80) by means of a clamping or latching connection (84).

8. The electrical machine (10) of claim 5, wherein the plug cover (76) has a metal layer for electromagnetic shielding and extends radially inside the pole housing as an EMV shield and is electrically connected thereto.

9. The electric machine (10) according to claim 5, characterized in that the plug member (18) together with the plug cover (76) is arranged radially completely outside the pole housing (12).

10. The electrical machine (10) according to claim 1 or 2, characterized in that the contact element (16) is arranged axially between the pole housing (12) and a gear housing (14), into which a rotor shaft (20) of the rotor (15) projects axially for torque transmission.

11. The electrical machine (10) according to claim 1 or 2, characterized in that the contact element (16) has a radially extending base body (32) with a through-opening (34) in the axial direction (24), through which the rotor shaft (20) passes, and an outer, circumferential wall (44) of the base body (32) forms an outer wall (45) of the electrical machine (10).

12. The electrical machine (10) according to claim 1 or 2, characterized in that the brush (26) is configured as a hammer brush (27) which is fixed by means of spring arms (29) to a brush element (17) manufactured separately from the contact member (16), which brush element is electrically connected at least to the contact member (16).

13. The electrical machine (10) according to claim 5, characterised in that the connection pin (42) passes through an intermediate wall (72) which separates the plug flange (40) from the receiving space (74), wherein the connection pin (42) is formed integrally with the conductor track (50) which extends in the receiving space (74) in a radial direction (23) and is formed to be bent axially into the plug flange (40), wherein an axial contact plate (70) in the receiving space (74) projects axially beyond the conductor track (50) extending radially therein.