CN114465395A

CN114465395A - Stator housing and electric drive unit having a stator housing

Info

Publication number: CN114465395A
Application number: CN202111320743.3A
Authority: CN
Inventors: M·沃尔默; J·费伦茨; U·梅茨
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2020-11-09
Filing date: 2021-11-09
Publication date: 2022-05-10
Also published as: DE102020214010A1

Abstract

The invention relates to a stator housing and an electric drive unit, comprising such a stator housing, a housing pot having a bottom face on an end face, a bearing receptacle for a rotor shaft extending in an axial direction being arranged centrally inside the bottom face, and a flange component being arranged on a cylindrical housing pot in the axial region of the bottom face, by means of which flange component the stator housing can be flange-connected to the other housing part, wherein the flange component forms a circumferential axial contact face for the other housing part over the entire circumference, and a first wall which surrounds the axial contact face is curved in the axial direction, the circumferential first wall being arranged radially opposite a cylindrical outer circumferential region of the housing pot, and the flange component is designed as a deep-drawn part which is produced separately from the housing pot and is welded to the housing pot, and a receiving opening being integrally molded on the flange component, the stator housing can be screwed to the other housing part by means of the receiving opening.

Description

Stator housing and electric drive unit having a stator housing

Technical Field

The invention relates to a stator housing and an electric drive unit, in particular for adjusting movable components in a motor vehicle, comprising such a stator housing, according to the type of the independent claims.

Background

DE 102014223804 a1 discloses an electric machine having a cylindrical stator housing made of metal. In order to fasten the electric machine to a component in a motor vehicle, a separately produced fastening flange is fixedly welded to the stator housing. The fastening flange surrounds the stator housing over its entire circumference and bears radially on the housing wall of the stator only at some radial projections. In order to flange the stator housing axially flush and flat to the other housing part, a mechanically stable and at the same time inexpensive interface is to be provided by means of a separately produced flange component. Such an interface will be described by the invention described below.

Disclosure of Invention

In contrast, the stator housing according to the invention and the electric drive unit having such a stator housing, which have the features of the independent claims, have the advantage that, by forming an axial contact surface on the end of the stator housing in the region of the bottom surface of the stator housing, which surface-wise contacts the drive unit on axially adjacent housing parts, which contact surface runs around the entire circumference, a flat interface is provided. The flange component forms a mechanically stable circumferential flange surface together with the bottom surface of the stator housing, by means of which the drive unit can be reliably axially supported in a planar manner on the adjacent housing part.

Advantageous refinements and improvements of the features specified in the independent claims are obtained by the measures cited in the dependent claims. Advantageously, a circumferential wall is integrally molded onto the circumferential axial stop surface, which extends approximately perpendicular to the axial stop surface in the axial direction. The circumferential wall bears directly radially against the outer circumference of the stator housing with a centering region, so that on the one hand the circumferential stop surface is precisely positioned radially and on the other hand the axial stop surface is reliably prevented from tilting relative to the housing pot.

In order to also better prevent twisting or tilting of the axial stop face, a circumferential second wall is molded in the axial direction, which extends approximately parallel to the circumferential first wall. By way of a variant, a fold region is formed between the two surrounding walls, on which fold region a circumferentially surrounding axial contact surface is preferably formed, which is oriented at least approximately perpendicular to the axial direction. In a further embodiment, two circumferential walls extending substantially parallel to one another can mechanically stabilize the radially outer edge region of the flange component in order to thereby prevent the axial contact surfaces from twisting.

Preferably, a receiving web in which an axial bore is formed as a receiving bore is integrally molded on the axial contact surface of the connection in a radially outward manner. In a first embodiment, the receiving tab with the receiving opening formed therein is located radially within the surrounding first wall or within the combination of the surrounding two walls, which is configured as a double wall. In an alternative embodiment, the receiving web with the receiving eye formed thereon is arranged radially between the inner circumferential wall and the second radially outer circumferential wall. In this embodiment, the receiving web is mechanically particularly stable. Since the receiving web likewise forms part of the axial contact surface, the axial contact surface can be prevented from being deformed during screwing of the receiving web.

In order to form a mechanically rigid axial contact surface facing the other housing part, the fold region is formed directly as a circumferential axial contact surface, by means of which the circumferential two walls are connected to one another.

The radial extent of the folding surface away from the receiving web is designed to be very small, so that the two axial walls can radially abut against each other. In the region of the receiving web, the radial distance between the two surrounding walls and thus the radial extent of the fold region is significantly greater. On the one hand, a structural space for the connecting bolt can thus be provided radially between the two surrounding walls. On the other hand, the deep-drawing tool can therefore be better axially inserted between the two surrounding walls in this region, so that a better production of such a flange component is possible.

In an alternative embodiment, the fold region between the two surrounding walls does not face axially toward the adjacent housing, but is remote from it. The fold region between two adjacent walls running parallel thereby forms a rigid circumferential flange which is reliably supported radially on the housing pot. The circumferential collar formed by the double wall also surrounds the receiving web radially on the outside, so that the receiving web is also mechanically stabilized and cannot bend relative to the plane of the axial stop surface.

It is particularly advantageous if a base ring extends radially inward from the circumferential wall toward the rotor shaft, said base ring covering an outer part of the floor of the housing pot. Thereby, the flange member on the base ring can be axially welded to the bottom surface of the housing tank. In this embodiment, the axial outer side of the base ring forms an axial abutment surface which is closed on the circumference and which bears directly against the other housing part. In this case, the forces acting on the drive unit can be transmitted directly from the bottom of the housing pot to the base ring, which is supported directly on the adjacent housing part. This further reduces the tilting moment between the drive unit and the adjacent housing part.

By axially bearing the base ring against the bottom surface of the housing pot, the two components can be welded to one another in the axial direction. For this purpose, particularly cost-effective resistance welding can be used, since the base surface is also well accessible for the welding tool from the interior of the housing pot.

By arranging the first housing wall radially directly opposite the outer circumferential surface of the housing pot, the circumferential first wall can be welded particularly advantageously to the outer circumferential surface in the radial direction. Laser welding can be used for this purpose, wherein the welding tool only has to be positioned radially outside the housing pot. In the construction of the laser weld seam, it is advantageous if the circumferential wall is arranged at a small distance from the surface of the outer circumferential region, which can be achieved, for example, in the circumferential region between the centering regions.

In order to reliably weld the base ring to the base surface in the axial direction, so-called welding grooves (schweii beta-sigke) are formed in the base ring, which extend in the axial direction toward the base surface. The base ring thereby bears axially directly against the base surface at defined points, so that very reliable welding points can be formed at these welding recesses. For example, a plurality of welding recesses are distributed uniformly over the circumference of the base ring, each of which rests on an outer annular surface of the bottom surface of the housing pot.

Instead of forming the bearing receptacle for the rotor shaft on the bottom of the housing pot, the bearing receptacle can also be formed directly in one piece with the flange component. For this purpose, an inner ring, in the center of which a bearing receptacle is integrally formed, extends radially inward from the base ring. For example, the bearing receptacle can be designed as a double-walled sleeve into which the rolling bearing can be inserted in the axial direction. Preferably, an axial stop is formed on an axially outer surface of the bearing sleeve, such that the rolling bearing is inserted axially into the bearing sleeve from the interior of the housing pot as far as the axial stop. In such an embodiment, the flange member, with the rotor shaft mounted therein, completely encloses the housing pot. Thus, a portion radially inside the bottom surface of the housing tank can be advantageously omitted, since this portion is formed directly by the flange member. Preferably, such a flange component is welded axially in the region of the radially outer base ring to the outer annular surface of the bottom surface of the housing pot. However, it is also possible for the flange component to be welded axially to the bottom side of the housing pot in the region of its intermediate ring.

If the user interface of the other housing part has a cylindrical axial projection, a radial step is advantageously formed between the base ring and the intermediate ring of the flange component, which radial step preferably extends over the entire circumference. The intermediate ring thus forms an axial recess relative to the axial contact surface of the base ring, into which an axial projection of the user interface can engage. After the flange connection of the drive unit, the axial contact surface of the base ring completely surrounds the cylindrical axial projection of the user interface.

The stator housing can be connected to the gear housing on the flange component by means of fastening screws, which can be screwed in the axial direction from the cylindrical sleeve into the housing wall of the gear housing.

The housing pot can be produced very cost-effectively from sheet steel by a deep-drawing method. Here, the bearing seat can already be integrally molded on the bottom side of the housing pot, or correspondingly an axial opening can be integrally molded on the bottom side of the housing pot, which axial opening is then covered by the bearing seat, which bearing seat is integrally molded on the flange component. The flange component can also very advantageously be produced as a deep-drawn component. The sleeve is open axially opposite the base surface, wherein the inner side of the sleeve forms a receptacle for a bearing cap of the rotor shaft.

For mounting the electric drive unit, a stator base body is inserted into the housing pot, on the stator teeth of which stator windings are arranged. The contact elements of the stator winding (in particular the wire ends) are guided axially through the bearing cap onto the connected electronics housing. Control electronics are arranged in the electronics housing, which control electronics control the energization of the individual coils. Advantageously, the rotor shaft projects through the bearing cap into the electronics housing, wherein a signal generator for detecting the rotor position is arranged at the end of the rotor shaft, for example. The signal generator interacts with a rotor position sensor of the electronics unit, for example, in order to electrically commutate the coils. On the opposite side of the housing pot, the rotor shaft projects through the bearing receptacle into the adjacent other housing part. In this case, it can be particularly advantageous to arrange a driven part at the end of the rotor shaft, which part transmits the torque of the electric motor to a transmission unit in the adjacent transmission housing, for example, in order to adjust movable parts in a motor vehicle or to drive a pump or a blower. Thus, high torques and torque fluctuations can also be transmitted by means of a reliable mechanical connection between the drive unit and the adjacent housing part via the mechanically stable flange component, without the electric drive unit being skewed relative to the adjacent transmission housing.

Drawings

Other features of the invention will be derived from the other embodiments of the description and the drawings, as they are described in the following examples of the invention. In which is shown:

figure 1 shows a cross-sectional view of a first embodiment of an electric drive unit according to the invention,

figure 2 shows an enlarged view of the stator housing according to figure 1,

FIG. 3 shows another embodiment of a flange member according to the present invention, and

fig. 4 shows another embodiment of a stator housing according to the invention.

Detailed description of the preferred embodiments

Fig. 1 shows an electric drive unit 10, in which a stator 13 is inserted into a stator housing 12. The stator housing 12 is a motor housing made of metal, and the stator base 14 is accommodated in the motor housing. The stator base 14 has, for example, a plurality of T-shaped stator segments 18 having stator teeth 16 on which electrical windings 20 are arranged. The stator segments 18 are composed of individual sheet metal laminations 26, wherein an insulation mask 24 is arranged on each end face of the stator segments 18. The stator segments 18 are each wound here with a single-tooth coil 22, the free winding wire ends 28 of which extend at the open end of the stator housing 12 through an axial opening in a bearing cover 30 into an electronics housing 32 in order to make electrical contact there with control electronics, not shown. The rotor 11 extends radially in the axial direction 8 within the stator base body 14. The rotor 11 has a rotor shaft 34 on which a rotor body 36 with permanent magnets 38 is arranged. In this exemplary embodiment, the rotor shaft 34 is supported in the bearing cap 30, which is arranged at an axially open end 41 of the stator housing 12, facing the electronics housing 32. The stator housing 12 comprises a cylindrical housing pot 40 with a cylindrical outer circumferential region 42. On a closed side 43 axially opposite the open side 41, a base surface 44 extends in the radial direction 7 transversely to the rotor shaft 34. A bearing housing 46 for a rotor bearing 48, preferably a ball bearing, is molded into the bottom surface 44. The housing pot 40 is preferably produced as a deep-drawn part in one piece with the bottom 44. The rotor shaft 34 projects with a free axial end 35 from the stator housing 12 through a rotor bearing 48 in order to transmit the torque of the electric motor 10 to a transmission or a pump or a blower. For this purpose, a driven element 49 is arranged on the rotor shaft 34 outside the stator housing 12, or the driven element 49 is formed on the rotor shaft 34.

The opposite end of the rotor shaft 34 projects through the bearing cap 30 into the electronics housing 32. A signal generator 47 for detecting the rotor position is arranged on the rotor shaft 34 and interacts directly with a sensor on the control electronics. The control electronics can evaluate the sensor signal in order to control the electronic commutation of the EC motor 10, for example. The control electronics are preferably realized by a circuit board 31, which is accommodated in an electronics housing 32. A flange component 50 is welded to the cylindrical housing pot 40, by means of which the drive unit 10 can be fastened to a further housing part 52, which is designed, for example, as a transmission housing 53. For this purpose, a receiving tab 54 is formed on the flange component 50, in which a receiving aperture 56 is formed, into which a corresponding connecting element 58 engages. For this purpose, in fig. 1, the connecting screw 59 is screwed into the other housing part 52 through the receiving opening 56. The flange component 50 is produced as a separate deep-drawn part and is welded directly to the cylindrical outer circumferential region 42. For this purpose, a circumferential first wall 61 is molded on the flange component 50, which first wall in this case at least in sections rests in the radial direction 7 on the outer circumferential region 42. The circumferential first wall 61 merges into a fold region 64 which integrally connects the circumferential first wall 61 to the circumferential second wall 62, which likewise extends substantially in the axial direction 8 along the circumferential first wall 61. The fold region 64 has an axial contact surface 66 with which the flange component 50 is axially seated against the other housing component 52.

Fig. 2 shows only the stator housing 12 of fig. 1 in an enlarged manner, the housing pot 40 of which is made of sheet steel, for example, as a deep drawn part. On the cylindrical outer circumferential region 42, a bottom surface 44, in which a bearing receptacle 46 is formed as a double-walled sleeve concentrically to the rotor axis, is integrally molded on the axial closing side 43. Therefore, the bearing receptacle 46 is integrally molded with the housing pot 40. The bottom surface 44 has an outer annular surface 45, which is connected to the bearing receptacle 46 via an intermediate region 68 arranged axially offset to the open side 41. In this embodiment, the flange component 50 extends completely radially outside the outer circumferential region 42, wherein the circumferential first wall 61 bears radially against the outer circumferential region 42. For this purpose, radially abutting centering regions 60 are formed on the circumferential first wall 61, wherein preferably the laser welding points 69 are formed between the centering regions 60 in the circumferential direction 9. In the receiving web 54 and in a first circumferential region 82 directly adjacent to the receiving web 54, the radial spacing 63 between the first circumferential wall 61 and the second circumferential wall 62 is configured to be greater than in a second circumferential region 81 that is further away from the receiving web 54. The receiving borehole 56 is arranged radially between an inner first circumferential wall 61 and a radially outer second circumferential wall 62. Furthermore, a sufficient intermediate space for the head of the connecting screw 59 is present between the circumferential first wall 61 and the circumferential second wall 61. In the second circumferential region 81, the two surrounding

walls

61, 62 preferably lie radially against one another. In this case, the circumferential second wall 62 extends in the axial direction 8 only over a partial region of the axial extent of the circumferential first wall 61. The axial contact surface 66 of the fold region 64 extends in particular in a closed manner over the entire circumference. The axial contact surface 66 lies approximately in a radial plane 67 with the outer annular surface 45 of the base surface 44.

Fig. 3 shows a variant of the flange component 50, as it can be welded to the housing pot 40 according to fig. 2, for example. The flange component 50 has a circumferential first wall 61, which is arranged radially opposite the outer circumferential region 42. A centering region 60, which centers the flange component 50 radially on the outer circumferential region 42, can also be formed on this outer circumferential region. A base ring 70, which extends radially toward the rotor shaft 34 along the bottom face 44, is integrally molded onto the circumferential first wall 61. A plurality of welding recesses 72 are formed on the base ring 70, which directly bear axially against the bottom 44 of the housing pot 40. The flange member 50 is preferably secured to the bottom surface 44 by resistance welding at the weld groove 72. In particular, resistance welding is performed before the stator 13 is mounted into the stator housing 12. The base ring 70 extends flat along the outer annular surface 45 of the bottom surface 44. The base ring 70 therefore overlaps radially with the bottom face 44, in particular with the outer annular face 45 of the housing pot 40. The axial outer side 71 of the base ring 70 forms the axial contact surface 66 of the stator housing 12 for the other housing part 52. The receiving webs 54 extend radially outward in one plane with the base ring 70. The first circumferential wall 61 surrounds the receiving webs 54 with the receiving openings 56 radially on the outside. In this embodiment, there is no surrounding second wall 62. The welding of the flange component 50 can alternatively or additionally also take place on the circumferential first wall 61 radially to the outer circumferential region 42.

Fig. 4 shows a further embodiment of the stator housing 12, wherein a further variant of the flange component 50 is fastened to the housing pot 40. Starting from the flange component 50 in fig. 3, an intermediate ring 78, on which the bearing receptacle 46 is formed directly centrally, extends radially inward from the base ring 70. This means that there is no molded-in bearing receptacle 46 on the bottom surface 44 of the housing pot 40. It is also possible to omit the intermediate region 68 on the bottom surface 44, since this region is closed off axially by an intermediate ring 78 of the flange component 50. Intermediate ring 78 is preferably axially offset relative to base ring 70, so that intermediate ring 78 forms axial step 76 toward open side 41. The bearing receptacle 46 is again preferably designed as a double-walled sleeve, on the axial outer side of which an axial stop 74 for the rotor bearing 48 is molded. The bearing receiving portion 46 can be produced together with the deep drawing of the flange component 50. In order to mechanically stabilize the flange component 50, a circumferential second wall 62 is optionally molded on its radially outer circumference, which extends substantially parallel to the circumferential first wall 62 in the axial direction 8. The fold region 64 between the first and the second

circumferential wall

61, 62 is shown here toward the open side 41 of the housing pot 40, so that the open gap between the two

circumferential walls

61, 62 is directed toward the other housing part 52. In particular, the two surrounding

walls

61, 62 can be supported radially against one another at least in sections, and preferably both are designed without interruption over the entire circumference. In this case, two

walls

61, 62 running parallel to one another surround the receiving eye 56 and the receiving web 54 radially on the outside. In turn, a welding recess 72 is preferably formed on the base ring 70 and/or the intermediate ring 78, on which the flange component 50 is fastened to the base face 44 by means of a welding point. The welding of the flange component 50 can alternatively or additionally also take place here again radially to the outer circumferential region 42 on the circumferential first wall 61.

It is to be noted that, with regard to the embodiments shown in the figures and the description, various combinations of the individual features with one another are possible. The specific shape and number of receiving tabs 54 and receiving eyelets 56 and connecting elements 58 can therefore be adapted to the respective application. Also, the curvature of the surrounding first wall 61 and/or second wall 62 can vary depending on the material and manufacturing method of the flange member 50 using the fold region 64. The radial and axial contours of the flange component 50 with the axial stop surface 66 and the axial step 76 can be adapted to the user interface of the other housing part 52. The electric drive unit 10 according to the invention is particularly suitable as an embodiment of an EC motor 10 for adjusting movable components or for a rotary drive in a motor vehicle. Such an electric motor 10 according to the invention can be used particularly advantageously in an external area, such as, for example, in an engine compartment or for power steering, where the electric motor can be subjected to extreme weather conditions and vibrations.

Claims

1. A stator housing (12) for an electric drive unit (10), in particular for adjusting a movable component in a motor vehicle, has

A cylindrical housing pot (40) having a base surface (44) on the end side, in the interior of which a bearing receptacle (46) for a rotor shaft (34) extending in the axial direction (8) is centrally arranged, and in the axial region of the base surface (44) a flange component (50) is arranged on the cylindrical housing pot (40), by means of which flange component the stator housing (12) can be flanged to a further housing component (52),

wherein the flange component (50) forms a circumferential axial contact surface (66) for the other housing part (52) over the entire circumference, and a first circumferential wall (61) which is arranged radially opposite a cylindrical outer circumferential region (42) of the housing pot (40) and is bent over in the axial direction (8) on the axial contact surface (66) and is designed as a deep-drawn part which is produced separately from the housing pot (40) and is welded to the housing pot (40), and a receiving opening (56) is integrally molded on the flange component (50), by means of which the stator housing (12) can be screwed to the other housing part (52).

2. The stator housing (12) as claimed in claim 1, characterized in that the circumferential first wall (61) bears at least in sections radially directly against a cylindrical outer circumferential region (42) and thereby the flange component (50) is centered relative to the housing pot (40).

3. Stator housing (12) according to one of the preceding claims, characterized in that a surrounding second wall (62) is molded on the flange component (50), which extends substantially along the surrounding first wall (61) in the axial direction (8) and is integrally connected with the surrounding first wall (61) by a fold region (64).

4. Stator housing (12) according to one of the preceding claims, characterized in that the receiving aperture (56) is configured on a radial receiving web (54) of the flange component (50) and the receiving aperture (56) is surrounded radially outside by a surrounding first and/or second wall (61, 62).

5. Stator housing (12) according to one of the preceding claims, characterized in that a receiving web (54) with a screw eye (56) is arranged radially between the surrounding first and second walls (61, 62), and in particular the screw web (54) is a component of a fold region (64) between the two surrounding walls (61, 62).

6. Stator housing (12) according to one of the preceding claims, characterized in that the fold region (64) forms an axial contact surface (66) on the closing side (43) facing the further housing part (52) and the radial spacing (63) between the encircling first and second walls (61, 62) varies, and preferably the radial spacing (63) is smaller in a first circumferential region (81) remote from the receiving web (56) than in a second circumferential region (82) directly adjacent to the receiving web (56).

7. Stator housing (12) according to one of the preceding claims, characterized in that the fold region (64) points axially away from the axial contact surface (66) and both the encircling first and second walls (61, 62) surround the screw tab (56) radially to the outside and in particular radially contact one another over the entire circumference.

8. The stator housing (12) according to any one of the preceding claims, wherein a base ring (70) is molded on the flange component (50), which base ring extends radially towards the rotor shaft (32) and overlaps the bottom surface (44) of the housing pot (40), wherein an axially outer side (71) of the base ring (70) forms an axial stop surface (66) towards the further housing part (52).

9. Stator housing (12) according to one of the preceding claims, characterized in that the flange component (50) is welded in the radial direction by a surrounding first wall (61) to the outer circumferential region (42) or axially by the base ring (70) to the bottom face (44).

10. Stator housing (12) according to any of the preceding claims, characterized in that the flange member (50) is welded to the housing pot (40) by means of laser welding or by means of resistance welding.

11. Stator housing (12) according to one of the preceding claims, characterized in that a welding groove (72) is molded on the base ring (70), which welding groove extends axially towards the bottom surface (44) and forms a material-locking connection with the bottom surface (44) during welding.

12. Stator housing (12) according to one of the preceding claims, characterized in that at the radial center of the base ring (70) a bearing receptacle (46) for the rotor shaft (34) is constructed in one piece with the base ring, wherein in particular the bottom face (44) of the housing pot (40) does not extend in the radial direction as far as the bearing receptacle (46) and the flange component (50) does not overlap the bottom face (44) of the housing pot (40) at a radial intermediate ring (78) surrounding the bearing receptacle (46).

13. The stator housing (12) as claimed in one of the preceding claims, characterized in that the intermediate ring (78) is arranged offset with respect to the stop face (66) axially away from the other housing part (52) and the bearing receptacle (46) is configured as a folded double-walled sleeve (86).

14. Stator housing (12) according to one of the preceding claims, characterized in that the housing pot (40) is formed by deep drawing from sheet metal and is configured axially opposite the bottom face (44) on its open side (41) to be completely open axially, wherein the inner side of the outer circumferential region (42) on the open side (41) forms a receiving region (29) for a bearing cover (30) of the rotor shaft (34).

15. An electric drive unit (10) having a stator housing (12) according to one of the preceding claims, wherein a rotor (11) is arranged in the stator housing (12), which rotor is supported at an axially open side (41) in a bearing cover (30), and an electronic unit for actuating the stator coils (20, 22) is arranged at the bearing cover (30), and wherein the rotor shaft (32) projects from a bearing receptacle (46) at the bottom side (44), wherein a driven element (49) is formed, which engages in the other housing part (52) when the flange member (50) is fixed at the latter, in order to transmit a torque to a transmission element in the other housing part (52).