WO2018210894A1

WO2018210894A1 - Electric machine, and method for producing an electric machine

Info

Publication number: WO2018210894A1
Application number: PCT/EP2018/062644
Authority: WO
Inventors: Armin Stubner; Christian Meyer; Hans-Peter Dommsch; Torsten Gmuend; Matthias Gog
Original assignee: Robert Bosch Gmbh
Priority date: 2017-05-19
Filing date: 2018-05-16
Publication date: 2018-11-22

Abstract

The invention relates to an electric machine (10), in particular an electronically commutated (EC) motor, and a method for producing same, comprising a pole housing (15) in which a stator (16) and a rotor (18) are accommodated, and a plug housing (33) made of plastic and having an integrated connection plug (37) is arranged axially on an open side (31) of the pole housing (15), wherein the plug housing (33) is surrounded by a metal cover (81) over its entire perimeter, which is sealingly welded to the open side (31) of the pole housing (15) by means of a peripheral laser weld seam (90), wherein an uninterrupted peripheral metal ring (88) is arranged as a beam protector radially inside the laser weld seam (90), which metal ring is positioned in the beam path of a laser (91) which can penetrate into the internal space of the electric machine (10) through a joining gap between the pole housing (15) and the metal cover (81) during laser welding.

Description

Description title

Electric machine and method for manufacturing an electrical machine

The invention relates to an electric machine, and to a method for producing such according to the preamble of the independent claims.

State of the art

With DE 10 2011 084 763 AI an electric machine has become known in which a stator is arranged in a pole pot. On the pole pot, a plug component is arranged, in which a rotor shaft is mounted. The plug component is in this case made of plastic and has electrical conductor elements for interconnecting the electrical winding of the stator. In this case, the coil wire ends of the windings are guided axially through the plug component and connected to the top side of the plug component with the conductor elements. A metal cover with cooling fins is mounted on the plastic plug component. The metal lid is clamped to the pole pot by a plurality of steel spring clips, so that the three components are fixed against each other. Disadvantage of such an embodiment is that no reliable heat dissipation and sufficient EMC shielding is ensured by the combination of a plastic plug component and the pole housing and lid made of metal. There are also known housing in which two metal components are welded together. In this case, there is the danger that laser beams can penetrate into the interior of the housing during a laser welding process and can damage more sensitive components with their high energy input. This disadvantage is to be remedied by the embodiment of the invention.

Disclosure of the invention Advantage of the invention

The device and the method according to the invention with the features of the independent claims have the advantage that the arrangement of a metal ring as beam protection on the inside of the joint gap between the pole housing and the metal lid during laser welding scattered laser beams are effectively absorbed. In this case, the metal ring in the beam path of the laser beams, which can penetrate into the housing during welding. The absorption of the laser beams in the metal ring protects other more sensitive components within the housing and introduces them

Energy is dissipated quickly in the metal ring. This makes us especially the arranged inside the housing plug plastic housing in front of a

Melting protected. The measures listed in the dependent claims advantageous refinements and improvements of the embodiments specified in the independent claims are possible. If the pole housing has a radial step at its open end in the radially outer region, then both the metal ring and the peripheral wall of the metal cover can be inserted axially into the radial step. As a result, both the metal ring and the peripheral wall of the metal cover reliably radially relative to the

Pol housing are fixed before the weld is formed in the radial gap between the peripheral wall and the pole housing. The welded on

Metal lid presses the metal ring reliably on the annular

Base of the radial step. By this arrangement of the metal ring axially below the peripheral wall is all stray radiation of the laser at

Welding reliably absorbed in the metal ring, since in such an embodiment, the laser beam is incident at a relatively shallow angle to the axial direction in the annular gap.

Since the connector housing is arranged axially above the metal ring, it is reliably shielded by the metal ring from penetrating laser beams. In this case, an axial spring element is advantageously arranged between the plug housing and the metal cover, which also presses the metal cover against the pole housing also the metal ring reliably against the Pole housing presses. If the metal lid directly axially on the metal ring, advantageously by means of the spring element and the connector housing can be clamped axially against the metal ring, so that the connector housing is reliably fixed by welding the metal lid to the pole housing in the electric machine.

For this purpose, the plug housing has an annular circumferential wall, the lower axial end face preferably bears directly against the metal ring. In this case, this axial end face abut the entire surface of the metal ring, or axially overlap the metal ring with an axial extension and extend in the region radially within the metal ring to the pole housing out. In the latter embodiment, the plug housing wall with respect to the metal ring - and thus centered with respect to the pole housing.

By forming an annular gap between the outside of the peripheral wall of the metal cover and the radial collar on the pole housing, the weld can be formed within this annular gap, whereby the weld can be made very reliable sealing. The annular gap forms a notch, so that the laser beam is directed to form the weld at a shallow angle to the axial direction in the annular gap. In this case, the metal ring is axially below the peripheral wall exactly in the beam path of the incoming laser beam and its reflected

Laser radiation.

In a preferred embodiment, the metal ring is formed as an integral part of the bearing plate. In this case, the end shield has a closed circumference in its radial outer edge. This closed

The peripheral edge is inserted as a metal ring in the radial collar of the pole housing and abuts against the base of the radial step. The peripheral edge is in this case formed as a flat metal ring on which axially rest both the peripheral wall of the metal lid and the connector housing axially. In this embodiment can be dispensed with a separate production of the metal ring, since the bearing plate can be formed as a bending stamped part very simple with the corresponding metal ring in one piece. This bearing plate receives a rolling bearing, by means of which the rotor is mounted inside the pole housing. At the radial step of the pole housing, a bead is formed over the entire circumference at the base of the step in the radially outer region,

preferably during deep drawing of the pole pot. In this annular bead can advantageously engage an integrally formed during the production of the metal ring punching burr, so that the metal ring reliably rests flat against the base of the radial step. The bead is sealed from the interior of the motor housing by the metal ring and the metal lid. Therefore, the bead also serves as a closed trap for foreign particles that arise during welding or pressing the metal ring into the pole housing.

The bearing plate advantageously has radially inside the metal ring recesses between the radial webs, on the one hand, the axial extension of the plug housing can protrude axially from top to bottom - and on the other hand, the mounting portions of the interconnection plate and the coil wire ends received therein axially reach from bottom to top. In order to realize a rotation lock between the plug housing and the metal ring, or the bearing plate, recesses are formed on the radial inner side of the metal ring and / or by the recesses in the bearing plate into which the plug housing wall engages axially. If, for example, the bearing plate is pressed into the radial collar, the connector housing can be secured against rotation by means of this positive connection.

Preferably, a sleeve-shaped bearing seat is formed in the center of the bearing plate, in which the rolling bearing is pressed axially. By the connection of the

Bearing seat on the curved radial webs to the circumferential metal ring, the axial press-fit forces for the rolling bearing in the bearing seat are less than its axial extrusion forces. As a result, the roller bearing is reliably secured in the sleeve-shaped bearing seat via the press-fit of the outer ring of the rolling bearing.

In an alternative embodiment, both the peripheral wall of the

Metal cover and the metal ring axially on a circumferential flange on the open side of the pole housing on. In this embodiment, the

Weld not arranged in an annular gap, but at the radial Outside of the peripheral wall and arranged on the axial end face of the flange. In this welding process, the laser beam is arranged at a larger angle to the axial direction, so that the laser beam is scattered relatively flat on the flange and can penetrate into the interior of the housing. Therefore, the metal ring is advantageously applied flat on the flange directly on the inside of the peripheral wall of the metal lid, so that all penetrating and scattered laser beams are absorbed by the metal ring. Such a metal ring is preferably formed as a separate component and is preferably arranged radially outside of the metal ring separately manufactured bearing plate. The bearing plate can engage in a radial step in the pole housing and a rotation with the

Have connector housing.

The cross section of the metal ring is particularly favorable rectangular or L-shaped. One side is always flat against the flange or at the base of the radial step. The plug housing rests against the axially opposite sides of the metal ring, so that both the rectangular and the L-shaped metal ring shield the plug housing axially upwards in front of the laser beams. The axial thickness of the metal ring - or the axially extending legs - are adapted in each case to the tolerances and the exact geometry of the joint between the metal lid and the pole housing. It is particularly favorable to form the metal ring with a dark surface, at least on the side where the laser beams impinge, in order to increase the absorption. This can be realized, for example, by scaling a steel material or anodizing an aluminum. The thermal conductivity of the material is so high that the irradiated laser energy can be dissipated quickly.

By the manufacturing method according to the invention, the metal lid can be reliably welded to the pole housing, without damaging sensitive components inside the housing. As a result, enough laser energy can be introduced to form a reliably sealing over the entire circumference sealing weld. Due to the integration of the metal ring in the bearing plate can on a separate attachment of the

Bearing shields are omitted, since by the axially resilient pressing of the Plug housing against the metal ring with the formation of the weld and the bearing plate is reliably fixed to the pole housing. It is in the

Metal lid inserted a ring seal against the opening for the connection plug, so that the metal lid is also reliably sealed against the axially exiting from the metal lid terminal connector.

If the metal lid is welded over its entire circumference by means of a weld with the flange of the pole pot, created on the base with the connector plug a very robust metal housing, on the one hand

vibration resistant, and on the other hand serves as an electromagnetic shield. Is formed on the cylindrical peripheral wall of the metal cover a radial gradation, the resulting axial

Stop surface on the inside of the metal lid can be used as an axial stop for the axial spring. It can simultaneously with the production of the metal cover the radial - and optionally the axial sealing surface for the

Ring seal are formed, and at the same time the radial space between the peripheral wall of the plug housing and the inside of the metal lid are provided for the tubular bourdon tube available.

Brief description of the drawings

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. Show it:

1 shows an embodiment of an electrical machine according to the invention,

2 is a partial view of another embodiment in section,

Fig. 3 is a detail view of another embodiment in section, and

Fig. 4 shows a bearing plate with a metal ring according to the invention.

1 shows an exemplary embodiment of a fully assembled electric machine 10, in which a stator 16 in a housing 14 of an electric machine 10 is used. In this case, the stator 16 has coil carriers 36, which are formed separately, for example, as individual segments 62, and are wound with electric coils 17. The housing 14 has a pole pot 15 formed as

Pol housing 15 which forms, for example, a magnetic yoke for the electric coil 17. The pole pot 15 has at its open end 31 to a flange 32, are placed on the other components. in the

Embodiment according to Figure 1, the pole pot 15 at its bottom surface 40 has an opening through which a rotor shaft 20 protrudes to a

To transmit torque of the electric machine 10 via an output member 64 to a transmission element, not shown. On the bottom surface 40, a first bearing seat 70 is formed, in which a first roller bearing 72 is inserted. The inner ring 73 of the first rolling bearing 72 is fixedly connected to the rotor shaft 20. Thus, the first roller bearing 72, a fixed bearing for the rotor 18. The rotor 18 has a rotor body 65 which carries permanent magnets 68 which cooperate with the electric coils 17. The rotor body 65 consists for example of individual, stacked laminations 66, in which

Recesses 67 are punched out for the permanent magnets 68. The

Coil wire ends 19 of the coils 17 project beyond the electric coils 17 in the axial direction 4. A wiring plate 22 is axially mounted on the stator 16, wherein from a plastic body 21 projecting

Conductor elements 23 are connected by means of fastening portions 25 with the coil wire of the coil 17. In this case, the electrical connections between the coil wire and the fastening sections 25 are formed, for example, by welding, soldering or crimping. In the described

Embodiment have exactly three conductor elements 23 each one

Connection pin 26 for the phases U, V and W on. The plastic body 21 is annular, so that in its central recess 44 the

Rotor shaft 20 of the rotor 18 can protrude. The plastic body 21 is supported in the axial direction 4 via integrally formed spacers 42 on the stator 16. The spacers 42 of the interconnection plate 22 are integrally formed on the radially outer edge thereof. In the exemplary embodiment, the spacers 42 abut axially directly on the winding carriers 36, on which the electric coils 17 are wound. The winding carriers 36 are formed here as individual segments 62 for each coil 17. It is on the winding supports 36 each one Insulating mask 61 for the electric coils 17 radially within the

Spacer 42 is arranged. The winding support 36 is composed, for example, of individual stacked laminations 113 and has a yoke element 118, on which at least one stator tooth 120 extends radially inwards. In the illustrated section through the yoke element 118, this is radially with a radial outer wall 119 with a press fit on the

Inner wall 115 of the pole housing 15 at. In this case, the laminations 113 may optionally be formed as closed in the circumferential direction 2 integral annular ribs, or as a single angle segments, the more

Single segments 62 of the stator 16 belong.

Axially above the Verschaltungsplatte 22, a bearing plate 54 is arranged, which abuts at its radially outer edge 53 on the pole pot 15. The bearing plate 54 has a second bearing seat 55, which engages axially in the central recess 44 of the wiring plate 22. In the second bearing seat 55 is a second

Rolling 56 recorded by means of which the rotor shaft 20 is rotatably mounted in the stator 16. The second rolling bearing 56 is formed, for example, as a ball bearing and is a floating bearing for the rotor 18 is an outer ring 58 of the second roller bearing 56 rotatably in the second bearing seat 55 and the inner ring 57 axially slidably mounted on the rotor shaft 20. The second rolling bearing 56 is arranged, for example, axially in the same plane as the interconnection plate 22, so that the electric machine 10 is formed very compact in the axial direction 4. The bearing plate 54 has in the exemplary embodiment individual radial webs 59, between which the receiving sleeves 27 formed as fastening portions 25 protrude axially upwards. The

Coil ends 19 of the coils 17 are inserted into the receiving sleeves 27, and for example, materially connected thereto. Likewise, the connection pins 26 extend from the plastic body 21 through the bearing plate 54 through to be able to be connected to corresponding contacts 30 of a connector plug 37. The wiring board 22 is the

Vibration damping by means of axial spring means 46 from the bearing plate 54 axially pressed down against the winding support 36. The spring means 46 generate an axial bias, which keeps the Verschaltungsplatte 22 accurately positioned over a wide temperature range and large shaking loads. Due to the design of the spring means 46 independently of the bearing plate 54, the elasticity of the material can be optimally adapted to the temperature differences and to the accelerations occurring. The rotor 18 is biased axially relative to the second roller bearing 56 by means of a compression spring 86. The compression spring 86 is supported on the one hand on the rotor body 65 and on the other hand on the inner ring 57 of the second rolling bearing 56.

Above the bearing plate 54, a plug housing 33 is arranged, on which the outer connector 37, not shown, is arranged for the power supply of the electric machine 10. On the plug housing 33, the electrical contacts 30 are arranged on the inside 39, which are connected to the connection pins 26 of the wiring plate 22. The wiring board 22 is connected to both the coil wire ends 19 and the electrical

Contacts 30 of the connector plug 37 is connected. For example

extend the electrical contacts 30 as contact tabs 34 axially downwards, so that they are arranged immediately adjacent to the connection pins 26 and then, for example, welded together. in the

Plug housing 33, a sensor element 74 is fixed, which with a

Signal generator 75 cooperates on the rotor shaft 20 to detect the rotor position. For this purpose, a magnet holder 78 is pressed on the free end 80 of the rotor shaft 20 after mounting the bearing plate 54, which receives a sensor magnet 76. Its rotating magnetic field is detected by the sensor element 74, which is designed as a high-resolution magnetic field sensor 77. On the

Plug housing 33 is axially a metal lid 81 joined, which is welded to the pole housing 15 by means of a weld 90. The plug housing 33 has a circular plug housing wall 83 and the metal lid 81 has a circular peripheral wall 82 which are arranged radially adjacent to each other. Between the plug housing 33 and the inner wall of the metal cover 81, a radial sealing ring 84 is pressed, which the electric machine 10 for

Connector 37 - preferably to an axial opening 87 in the metal lid 81 - seals out. Furthermore, between the plug housing 33 and the metal cover 81, an axial spring element 85 is arranged, which is the

Plug housing 33 axially pressed against the pole pot 15. The metal cover 81 is connected in the exemplary embodiment by means of laser welding to the open end 31 of the pole housing 15. Schematically is a

Beam path of the laser beam 91 is shown, which can penetrate during the welding process between the metal lid 81 and the pole housing 15 in the interior of the housing 14. So that the laser beam 91 does not hit the plug housing 33 made of plastic here, a metal ring 88 is arranged in the potential beam path of the laser beam 91, which absorbs the energy of the laser beam 91 and dissipates the heat generated thereby well. The metal ring 88 is axially on the flange 32, and radially within the peripheral wall 82 of the

Metal cover 81, which also bears axially on the flange. The

Plug housing 33 lies with its plug housing wall 83 axially on the metal ring 88. Thus, the plug housing 33 is axially and / or radially separated by the metal ring 88 of the laser beam 91 inside the housing. On the left side of the image, the metal ring 88 has a rectangular cross section, so that one leg extends in the axial direction 4 and another leg in the radial direction 3. In the right side of the picture, the metal ring 88 is a flat ring

formed whose extent in the radial direction 3 is greater than in the axial direction 4. Radially within the metal ring 88, the bearing plate 54 is preferably arranged. The bearing plate 54 here has axial extensions 52 which engage in a circumferential radial collar 13 on the open side 31 of the pole housing 15. By firmly welding the metal cover 81, the plug housing 33 is pressed axially against the metal ring 88 and this against the flange 32 by means of the spring 85, and thereby securely fixed. On the bearing plate 54 an axial extension 50 is formed as a rotation, which in a

corresponding recess 49 engages in the connector housing 33. Of the

Metal ring 88 preferably has a dark, such as black

Surface that can be made by scaling or anodizing. As a material for the metal ring 88 is preferably steel or aluminum

used.

In Fig. 2, another embodiment of an electric machine 10 according to the invention is shown in section. The connector 37 extends from the connector housing 33, starting in the axial direction 4, wherein the connection pins 26 of the U, V, W phase as connector pins 28 in a Plug collar 38 are guided. In this case, the plug collar 38 extends for a corresponding mating connector in the radial direction 3. Axial over the plug housing 33, the metal cover 81 is again joined, protrudes through the axial opening 87 of the connector 37. The peripheral wall 82 of the metal lid 81 is in this embodiment not directly on the flange 32 of the pole housing 15, but axially on the metal ring 88. The metal ring 88 is formed here as part of the bearing plate 54, which is made as a bending edge part. Here, the radially outer edge 53 forms the closed, circumferential metal ring 88. The metal ring 88 is in this case within a circumferential radial collar 13 at the open edge 31 of the pole housing 15. The weld 90 between the metal lid 81 and the pole housing 15 is in this case in a circumferential, arranged wedge-shaped gap 92 extending from the open end 31 in the axial direction 4 for

encircling collar 13 extends. In this weld 90, the laser beam 91 is directed axially steeper downwards, so that it is absorbed by the axially lower metal ring 88 inside the housing 14. In this case, the metal ring 88 shields the plug housing 33 from the weld seam 90. In this case, the plug housing 33 is supported axially on the metal ring 88 and is braced axially relative to the metal cover 81 in the axial direction 4 by means of the spring element 85. The bearing plate 54 in turn has radial webs 59, which connects the outer edge 53, which forms the metal ring 88, radially with the second bearing seat 55. Between the radial webs 59 recesses 51 are formed through which axial extensions 35 of

Plug housing wall 83 axially reach through. The coil wire ends 19 and the associated attachment portions 25 of the interconnection plate 22 also engage axially through these recesses 51 therethrough. In Fig. 2, further, a mounting flange 100 is shown, which at the radial

Outer wall 101 of the pole housing 15 attached - preferably also welded - is. By means of the mounting flange 100, the electric machine 10 can be fastened to the motor vehicle, preferably screwed. Due to the design of the bearing plate 54 with the sleeve-shaped bearing seat 55 which is connected via the radial webs 59 to the metal ring, the axial Auspresskräfte for the second roller bearing 56 from the bearing seat 55 are greater than the axial press-fit forces. As a result, the outer bearing ring 58 is very reliably secured in the bearing seat 55. This effect is reinforced when at the radial inner edge of the bearing seat 55 still a burr of the latter

Manufacture is formed, which clings to the peripheral surface of the bearing 56.

FIG. 3 shows a further embodiment as a detail view corresponding to FIG. 2.

Again, the metal ring 88 is formed as an integrated part of the bearing plate 54, which within the circumferential radial collar 13 of the

Polgehäuses 15 is arranged. In this case, an encircling annular bead 12 is formed on an axial base surface 9 of the collar 13, the

optionally can receive a burr of the metal ring 88. The bead can be pressed as an annular groove preferably during deep drawing of the pole housing 15 in the axial direction 4 in the base 9. In addition, the bead 12 can also absorb chips that arise during the pressing of the metal ring, which is for example part of the bearing cap in the pole housing 15. At the

Attaching the laser weld 90 can also create dirt particles that can collect in the bead 12. The peripheral bead 12 forms with the pole housing 15, the metal ring 88, the metal cover 81 and the laser weld 90 a closed catching space in which the chips and dirt particles are held and so penetration of these particles is prevented in the interior of the engine.

The circumferential collar 13 forms a radial step 11 of the pole housing 15, at the base 9 of the metal ring 88 abuts axially. In this embodiment, the plug housing wall 83 is axially over the entire surface of the metal ring 88, and in particular has no axial extensions 93. The axial end face 96 of the peripheral wall 82 of the metal lid 81 is also flat against the metal ring 88. In the exemplary embodiment, the wall thickness of the circumferential wall 82 in the region of the weld 90 is slightly thinner than axially further spaced from the weld 90. The weld 90 fills the wedge-shaped gap 92 between the peripheral wall 82 and pole housing 15 - preferably completely - from. In this case, laser welding methods are applicable, which introduce additional welding material in the weld 90, or melt only the material of the metal lid 81 and the pole housing 15. The Spring element 85 for axial clamping of the plug housing 33 relative to the metal cover 81 is formed in particular in the form of annular corrugated discs, which provide an axial spring travel available.

4 shows a bearing plate 54 with a second rolling bearing 56 inserted, as it is installed, for example, in the electric machine 10 according to FIG. 2. From the central bearing seat 55, the radial webs 59 extend to the radially outer edge 53. This peripheral edge 53 is simultaneously formed as a metal ring 88, which penetrates into the housing 14

Laser beams 91 absorbed. The bearing plate 54 is here formed as a stamped and bent part made of steel, wherein between the radial webs 59, the recesses 51 are punched out. In the area of the recesses 51, a positive connection 94 is punched out on the metal ring 88 on its radial inner side, in which the axial extensions 93 of the plug housing wall 83 can engage. As a result, the plug housing 33 forms an anti-rotation with the bearing plate 54. The bearing plate 54 is in this case hat-shaped, so that the metal ring 88 axially spaced from the second bearing seat 55 is arranged. The two axial planes are connected to each other by the bent radial webs 59 in the radial direction 3 and axial direction 4. In this case, 59 beads 99 are formed for stabilizing the bearing plate 54 along the radial webs, for example. Optional radial projections 95 are formed on the outer circumference of the metal ring 88, which can be pressed into the rotating radial collar 13. The metal ring 88, which is designed as part of the bearing plate 54, is preferably pressed only on the radial projections 95 on the pole housing 15. Between the radial projections 95, a degassing gap between the metal ring 88 and the pole housing 15 is formed in the circumferential direction 2, so the loose particles that arise during welding of the circumferential laser weld 90, pass through the degassing gap in the catching space of the bead 12 and held there become. The welding process begins and ends preferably between the radial projections 95. For example, in FIG. 4, six radial projections 95 are formed uniformly over the circumference, preferably in the region of the webs 59. However, the radial projections 95 may also be formed as double lugs, which are each arranged in pairs in the region of the two edges of the webs 59. It should be noted that, with regard to the exemplary embodiments shown in the figures and the description, a variety of possible combinations of the individual features are possible with one another. The arrangement and shape of the metal ring 88 can be adapted to the specific geometry of the pole housing and the metal cover 81, wherein the metal ring 88 is correspondingly in the beam path of the laser beam within the housing 14. In particular, the metal ring 88 may be manufactured as a separately manufactured component or integrated into the end shield 54. In this case, the bearing plate 54 in a process step with the making of the weld 90 on

Pol housing 15 are fixed. The inventive drive unit 10 is particularly suitable as an embodiment of an EC motor for adjusting movable components in the motor vehicle. In this case, such an electric motor 10 according to the invention can be used particularly favorably in the outside area, for example in the engine compartment, preferably for adjusting moving parts or operating pumps in the engine compartment, where it is exposed to extreme weather conditions and shocks.

Claims

claims

An electric machine (10), in particular an electronically commutated EC motor, with a pole housing (15) in which a stator (16) and a rotor (18) is received, and axially on an open side (31) of the pole housing (15) a plug housing (33) made of plastic with an integrated connection plug (37) is arranged, wherein the

Plug housing (33) over its entire circumference of one

Metal lid (81) is sealed, which is welded to the open side (31) of the pole housing (15) by means of a circumferential laser weld (90), wherein radially inside the laser weld (90) has a continuous circumferential metal ring (88). is arranged as a beam protection, which is in the beam path of a laser (91), which can penetrate during laser welding through a joint gap between the pole housing (15) and the metal lid (81) in the interior of the electric machine (10).

2. Electrical machine (10) according to claim 1, characterized in that the metal ring (88) in a radial step (11) of the pole housing (15) is inserted and against an axial base surface (9) of the radial step (11).

3. Electrical machine (10) according to claim 1 or 2, characterized

characterized in that plug housing (33) is formed of plastic and axially - in particular by means of a spring element (85) between the plug housing (33) and the metal cover (81) - pressed against the metal ring (88).

4. Electrical machine (10) according to one of the preceding claims,

characterized in that the plug housing (33) has a

cylindrical peripheral wall (83) whose axially lower edge rests directly on the metal ring (88).

Electric machine (10) according to any one of the preceding claims, characterized in that the cylindrical peripheral wall (82) of the metal lid (81) engages axially in the radial step (11) of the pole housing (15) and rests axially directly on the metal ring (88) ,

Electric machine (10) according to one of the preceding claims, characterized in that the laser weld (90) is arranged axially above the metal ring (88), in particular in an annular notch (92) between the outside of the cylindrical peripheral wall (82) and the axially upper peripheral edge of the radial step (11) of the pole housing (15).

Electric machine (10) according to one of the preceding claims, characterized in that the metal ring (88) as a radially outer edge (53) of a - in particular one-piece - bearing plate (54) is formed, in which the rotor (18) by means of a rolling bearing (56) is stored.

Electric machine (10) according to one of the preceding claims, characterized in that on the axial base surface

(9) on the radial outer side of an annular bead (12) in the axial direction (4) is formed, the a punching burr of the metal ring (88) or chips, which arise when pressing the metal ring (88) in the pole housing (15) or welding particles of the laser weld (90) record and / or can hold.

Electric machine (10) according to one of the preceding claims, characterized in that the bearing plate (54) between the metal ring (88) as its outer periphery and a central

Bearing receptacle (55) for the rolling bearing (56) radial webs (59), between which in the circumferential direction (2) recesses (51) are formed, and the plug housing wall (83) in sections with axial extensions (93) axially into the recesses (51 ), wherein preferably the axial extensions (93) bear radially against the metal ring (88).

10. Electrical machine (10) according to any one of the preceding claims, characterized in that the axial extensions (93) form a rotation lock with the bearing plate (54), wherein the radial webs (59) preferably angled or arched axially to the metal ring (88) are and the bearing receptacle (55) is designed as a central sleeve whose transition to the radial webs (59) axially spaced from the metal ring (88) is arranged.

11. Electrical machine (10) according to one of the preceding claims,

characterized in that the metal cover (81) and the metal ring (88) arranged radially inside thereof abut axially on a flange (32) of the pole housing (15) and the laser weld (90) on the radial outside of the metal cover (81). also formed axially on the flange (32).

12. Electrical machine (10) according to one of the preceding claims,

characterized in that the axially lower edge of the peripheral wall (82) of the metal lid (81) is located on the same radial plane directly between the laser weld (90) and the metal ring (88)

is arranged, in particular, the axially lower edge of

Plug housing wall (83) is arranged completely radially outside the bearing plate (54).

13. Electrical machine (10) according to one of the preceding claims,

characterized in that the metal ring (88) is formed as a separately manufactured component having in the circumferential direction (2) viewed an L-shaped cross-section or a rectangular cross-section, the latter being arranged in particular edgewise or horizontal.

14. Electrical machine (10) according to one of the preceding claims,

characterized in that the metal ring (88) has a dark - in particular black surface for absorbing the laser beams (91) - and is preferably made of aluminum or steel.

15. A method for producing an electrical machine (10) according to one of the preceding claims, characterized by the following steps: Assembly of the stator (16) and the rotor (18) in the pole housing (15), such that the metal bearing plate (54) is inserted axially into a radial step (11) at the open edge (31) of the pole housing (15), placing of the plug housing (33) on the peripheral edge (53) of the bearing plate (54), which is designed as a closed metal ring (88),

Axial joining of the metal lid (81) on the plug housing (33) - in particular so that a connection plug (37) of the

Plug housing (33) axially through a recess (87) of the

Metal cover (81) protrudes - wherein the metal cover (81) by means of a spring element (85) presses the plug housing (33) axially against the metal ring (88),

Dense welding of the metal cover (81) to the pole housing (15) by means of a laser beam (91).