WO2020148160A1

WO2020148160A1 - Stator mounting of a stator in a housing which accommodates the stator

Info

Publication number: WO2020148160A1
Application number: PCT/EP2020/050460
Authority: WO
Inventors: Dirk Zeise; Jakob Van Der Meer; Björn Hille
Original assignee: Volkswagen Aktiengesellschaft
Priority date: 2019-01-14
Filing date: 2020-01-09
Publication date: 2020-07-23
Also published as: CN113273056A; DE102019200336A1

Abstract

The invention relates to an interlockingly non-rotatable stator mounting of a stator (1) in a housing (2) which accommodates the stator (1). The non-rotatable interlocking fit is formed by means of connection means (3) introduced between the stator (1) and the housing (2), for which purpose the connection means (3), in each case comprising a shaft (4) and a head (5), are introduced into central receptacles (6) of the stator (1) and the stator (1) is mounted in stator bearings (7) of the housing (2) by means of the connection means (3). There is a press connection in each case between the stator bearing (7) and the head (5) as well as between the stator bearing (7) and, facing away from the head (5), an end portion (8) of the shaft (4) of the connection means (3) located in the stator bearing (7).

Description

description

Stator suspension of a stator in a housing accommodating the stator

The invention relates to a positively rotationally fixed stator suspension of a stator in a housing accommodating the stator. Here, the non-rotatable positive connection is formed by means of connecting means inserted between the stator and the housing, for which purpose the connecting means, each having a shaft and a head, are introduced into central receptacles of the stator, and the stator is suspended in the stator bearings of the housing via the connecting means.

As a rule, stators of electrical drives or hybrid drives are pressed or shrunk in a housing or a housing part. Torques occurring during operation are thus transmitted from the stator to the housing via a force fit due to the press fit. In order to ensure torque transmission over the entire operating temperature range, such a press fit must be carried out with a correspondingly large excess. The established press fit consequently leads to high mechanical loads in the housing, which must also absorb the torques that occur during operation. A centering of the stator in the housing is usually realized by contacting the stator surface in the housing, with a stipulated rotational position of the stator being determined by an additional one

Alignment element is carried out.

In addition to pressing or shrinking the stator, there is also the possibility of axially screwing the stator against the housing. For this purpose, the stator regularly has on its outer surface, and in this case in particular tabs integrally formed on the stator sheets of the stator for receiving screws. The stator is screwed into the housing in such a way that, due to the pretensioning force of the screws

Surface pressure acts on an axial stop surface of the stator in the housing, as a result of which torques occurring during operation are in turn transmitted non-positively from the stator to the housing. The design of the screw connection used for the screw connection is critical, since the stator, as a package consisting of a large number of individual stator sheets, tends to settle over the course of its operating time, as a result of which the surface pressure is minimized due to a decreasing preload force of the screws. This behavior must be interpreted

be taken into account and compensated. The centering and the determination of the target rotational position of the stator is accomplished by centering the outer diameter and using at least one sleeve. In the case of very long stators, centering is also carried out regularly on both long sides of the stator.

In addition, torque-proof torque transmissions between the stator and the housing are known from the prior art in a form-locking manner.

In this context, generic DE 102 57 889 A1 describes fastening the stator in a housing by using brackets. These brackets are designed as double-leg brackets or split pins, inserted into axial grooves between the housing and the stator and wedge the stator and housing in the tangential direction, so that the torque transmission between the housing and the stator takes place via a positive connection. It can also be provided that the clamps are locked in the axial direction to improve the connection between the stator and the housing. The centering of the stator in the housing is also ensured via the brackets, with a plurality of the brackets being arranged in the circumferential direction of the stator for this purpose. However, the large number of brackets used is disadvantageous, as a result of which the structure is overdetermined and small

Tolerances must exist.

DE 10 2009 010 177 A1 also discloses a connection of the stator and housing of an electric motor arrangement in a hybrid transmission, with the housing and stator

Adapter sleeves are used in axial grooves. As a result, a transmission of torques occurring during operation is established by means of a positive connection between the stator and the housing, which due to the pretensioning of the adapter sleeve also with a

thermal expansion should be largely ensured.

EP 1 592 107 A2 furthermore shows the fastening of a stator consisting of stator sheets in a housing of a generator, an additional support ring structure being arranged between the stator and the housing, into which the actual stator is inserted. The connection between stator sheets or stator and

Back-up ring structure is realized by profile bars formed on the back-up ring structure at a spacing in the circumferential direction and, depending on the embodiment, differently shaped, which engage in profile grooves formed on the stator and interacting indirectly with the profile bars. The profile bars can have a different cross-sectional shape from the profile grooves, since between profile bars and profile grooves depending on

Embodiment differently designed wedge elements are arranged. Essentially however, these wedge elements serve to compensate for tolerances between profile bars and profile grooves.

Against this background, the invention is based on the object of designing the stator suspension of the type mentioned at the outset in such a way that overdetermination of the stator suspension is avoided.

This object is achieved with a stator suspension according to the characteristics of the

Claim 1. The subclaims relate to particularly expedient developments of the invention.

According to the invention, a positively rotationally fixed stator suspension is therefore provided, in particular for arranging a stator in a housing accommodating the stator. In this case, the housing and stator should be designed as an assembly of an in particular rotating electrical machine such as an electric motor and / or as a device including such a rotating electrical machine such as a hybrid transmission. Furthermore, according to the invention, the non-rotatable positive connection is formed by means of connecting means introduced between the stator and the housing, for which purpose the connecting means, each having a shaft and a head, are introduced into central receptacles of the stator and the stator is suspended or arranged in the stator bearings of the housing via the connecting means.

There is a press connection between the respective stator bearing and the head as well as the stator bearing and an end section of the shaft facing away from the head of the connecting means respectively arranged in the stator bearing, as a result of which there is a non-positive connection in the axial direction between the stator bearing and head as well as the stator bearing and end section of the shaft.

As a result, the stator can be secured against axial displacement in the housing on the one hand, and centered relative to the housing on the other hand and a desired rotational position can be defined. The non-rotatable positive connection present via the connecting means is accordingly in

tangential direction, or in the circumferential direction of the stator, so that a

Torque transmission between the housing and stator can take place.

The connecting means, which are generally preferably designed as bolts, should be aligned with their longitudinal axis in the axial direction of the stator or the housing and should be spaced apart in the circumferential direction. Particularly preferably, two stator bearings should also be formed on the housing, in which the stator is suspended via a connecting means, so that overdetermination can advantageously be avoided. If more than two connecting means are to be provided, it would also be necessary to make the connecting means hollow and slotted over the entire length in order to avoid overdetermination or one

To allow tolerance compensation.

It should also be noted that the stator bearings, for example, in addition to the outer wall of the housing, can also be formed inside the housing.

It also turns out to be favorable if each stator bearing has at least two sections, a first section being designed as a partial cylinder with a shaft receptacle and a second section as a partial hollow cylinder which is not completely closed in the circumferential direction. The shaft receptacle can be designed as a hole, in particular as a blind hole, and would also have to adjoin the partial hollow cylinder directly, so that the end section or part of the end section of the shaft of the connecting means can engage in the shaft receptacle. The shaft receptacles simplify assembly, in particular the insertion of the stator into the housing.

A promising embodiment of the invention is particularly given when the press connection of the end section and stator bearing between the shaft holder of the

Stator bearing and the end portion of the shaft and the press connection of the head and stator bearing are formed between the partial hollow cylinder and the head of the connecting means. As a result, the stator can be suspended or arranged in an advantageously simple manner in the housing via the connecting means, the stator being due to the contact areas of the connecting means which are spaced as far as possible from one another

Stator bearing is guided and centered over its length in the housing.

In a further advantageous development of the invention, the partial hollow cylinder of the stator bearings does not completely encompass the central receptacle and / or the head of the connecting means in the circumferential direction of the partial hollow cylinder, but at an angle greater than 180 degrees. In addition, an opening angle of the partial hollow cylinder is less than 180 degrees. This enables a quasi-optimal mounting of the stator with at the same time a higher axial force effect against axial displacement of the stator than at angles less than 180 degrees or opening angles of the partial hollow cylinder greater than 180 degrees. In an extremely advantageous development of the invention, the end section of the shaft corresponds to a protrusion of the shaft relative to the center mount. In addition, it is considered to be extremely inexpensive if the head strikes the central intake. As a result, the press connection is correspondingly present in the protrusion of the shaft relative to the central receptacle, which, when the head of the connecting means strikes the central receptacle, means that the stator, even when there is a simplified insertion of the

Connecting means in the game between the middle receiving means and connecting means enabling no axial displacement. The striking of the head on the middle uptake is comparatively easy to realize by - as in the

Generally - the head diameter of the head is larger than the shaft diameter of the shaft of the connecting means.

It is conceivable in this context, as well as in general, that there is also a stop or an abutment of the stator on a rear wall of the housing.

In addition to a play between the middle receptacle and the connecting means or the shaft of the connecting means, however, there is also the possibility that there is also a press connection between a receiving area of the shaft located between the head and end section of the shaft and the middle receptacle.

An embodiment of the invention is also to be regarded as profitable if the end section of the shaft is longer than the head of the connecting means. The length of the end section can be 1.5 times to 2.5 times, preferably 1.8 to 2.2 times the length or height of the head. However, the length of the end section is particularly preferably twice the length or height of the head of the

Lanyard. Due to the increased length of the end section compared to the head, it can advantageously be possible to insert the end section of the connecting means or the connecting means into the shaft receptacles formed in the stator bearing and to pre-position the stator for the insertion process before the heads of the

Connect the lanyard to the stator bearing as well. Since the insertion of the stator into the housing is not necessary due to the press connection to be established between the end section and the stator bearing and the head and stator bearing

insignificant axial force is connected to the connecting means, this can be minimized during the critical prepositioning of the stator due to the increased length of the end section of the connecting means compared to the head, since initially only one correspondingly less force must be applied to the end sections in the

Shaft stock.

Furthermore, it is promising if each center receptacle is formed on the stator radially outward from an outer surface of a stator pack of the stator and thus extends in the direction of the housing, thereby simplifying the centering of the stator and the determination of its desired rotational position. This can also make it possible for center receptacles, into which no connecting means have been introduced, to be used for centering and / or for determining the desired rotational position of the stator. It is conceivable here that centering and / or aligning rails are formed in or on the housing for the central receptacles into which the

Intervene borrowings. These centering and / or aligning rails would be shaped in such a way that center receptacles in which connecting means are introduced cannot engage in the centering and / or aligning rails. These would also have a relative angle to the stator bearings, via which the determination of the target rotational position can be made possible. For example, with two stator bearings and two centering and / or

Guide rails to choose a relative angle or angle offset different from 90 degrees.

Furthermore, it should also be provided that the central receptacle formed on the lateral surface extends over the entire length of the stator packet, in each case

Longitudinal sections of the central receptacle on which the stator laminations which form the stator stack by stacking are formed. The stator package of the stator and the center receptacles could thus advantageously be produced simply, in particular by stamping the stator laminations from an electrical sheet and stacking them.

An advantageous embodiment of the invention is further characterized in that the central receptacle does not completely surround the shank of the connecting means in the circumferential direction, but at an angle greater than 180 degrees, as a result of which a cross section of a contact surface of the contact means with the shank of the connecting means

Middle uptake would be determined by a circular arc with a central angle greater than 180 degrees. The incomplete closure can ensure that, in addition to the end section of the shaft of the connecting means, only the head of the

Connection means forms a contact with the stator bearing and thus the press connection. This avoids overdetermination and also allows the production of funds to be carried out with higher tolerances. It is also promising if the stator is secured against an axial one

Displacement between the housing and stator and / or connecting means there is an additional, in the axial direction acting - in particular non-positive and / or positive - securing connection.

If the securing connection is implemented here by a locking device acting on the housing insert side on the heads of the connecting means and / or the stator, this is the case

to be regarded as advantageous in that there is easier access to the stator and / or the heads of the connecting means. Furthermore, due to the structural conditions, a high variety of variants of the locking device, which can be adapted to a respective stator-housing combination, can be ensured. The locking device can be, for example, a gear component and / or a locking device in the manner of bearing glasses. It should be mentioned that the side or region from which the stator is inserted into the housing is to be understood as the housing insertion side.

A further development of the invention is also to be regarded as advantageous if the

Security connection is realized by an axial screw connection between the housing and shaft of the connecting means. For this purpose, a through hole should be provided in particular in the first section, that is to say the partial cylinder of the stator bearing, which is connected to the shaft receptacle formed in the first section, so that a screw engages the

Pass through hole and can engage in a core hole with an internal thread or an internal thread bore extending from an end face of the shaft facing away from the head in the direction of the head of the connecting means.

The invention permits numerous embodiments. To further clarify its basic principle, one of these is shown in the drawing and is described below. This shows in

1 shows a further development of the stator suspension according to the invention;

2 shows a sectional illustration of a stator;

3 is a frontal view of a stator;

4 shows a stator in two representations; Fig. 5 shows an individual representation of a connecting element.

FIG. 1 shows a further development of a stator suspension according to the invention, the figure representing a partial exploded drawing. The stator suspension serves for the arrangement of the stator 1 in the housing 2 receiving the stator 1. The arrangement of the stator 1 in the housing 2 takes place by means of a non-rotatable positive connection, which is realized via two connecting means 3 inserted between the stator 1 and the housing 2. For reasons of illustration, FIG. 1 merely shows a connection means 3 designed as a bolt, a further connection element 3 being arranged on the side of the stator 1 that is not shown in the illustration. The connecting elements 3 have a corresponding angular offset of 180 degrees, which each consist of the shaft 4 and the head 5 and are introduced into two center seats 6 of the stator 1. Here again, one of the funds 6 in FIG. 1 cannot be seen due to the illustration. However, both of the stator bearings 7 of the housing 2, in which the stator 1 is suspended via the connecting means 3, are clearly shown. There is a press connection between a respective stator bearing 7 and the head 5 and the end section 8 of the shaft 4 facing away from the stator bearing 7 and the head 5 of the connecting means 3 respectively arranged in the stator bearing 7, the end section 8 of the shaft 4 opposite the projection of the shaft 4 corresponds to the funding 6. The end section 8 of the shaft 4 is longer and twice as long as the head 5 of the connecting means 3.

FIG. 2 shows a sectional illustration of the stator 1 in the housing 2, which shows that each stator bearing 7 has two sections, the first section as a partial cylinder 9 with a shaft receptacle 10 and the second section as a partial hollow cylinder 11 that is not completely closed in the circumferential direction is trained. The end section 8 of the shaft 4 is received between the shaft holder 10, which can be seen more clearly in the detailed illustration shown, a press connection being formed between the end section 8 and the shaft holder 10. Accordingly, the press connection is also formed between the partial hollow cylinders 11 and the heads 5 of the connecting means 3. To secure the stator 1 against axial displacement of the stator 1 relative to the housing 2, there is also an additional securing connection acting in the axial direction, this securing connection being realized by the axial screw connection 14 between the housing 2 and the shaft 4 of the connecting means 3. For this purpose, the screw inserted in the countersunk hole or the countersunk hole formed in the partial cylinder 9 engages in the internal threaded bore made axially in the shaft 4 of the connecting means 3. 3 shows a frontal view of stator 1 and housing 2, wherein a respective partial hollow cylinder 11 of the two stator bearings 7 does not completely surround the head 5 of the connecting means 3 arranged in the stator bearing 7 in the circumferential direction of the partial hollow cylinder 11, but at an angle greater than 180 degrees. In addition to the two center mounts 6 of the stator 1, in which the two connecting means 3 are arranged, two center mounts 6 are also formed on the stator 1, in which no connecting means 3 are arranged. This

Center receptacles 6, on the other hand, engage in centering and straightening rails 16 formed in the housing 2, these mutually having an angular offset of 180 degrees. To the

Stator bearings 7, on the other hand, have an angular offset which is between 0 degrees and 90 degrees or 90 degrees and 180 degrees, but differs from 90 degrees in a range of 10 to 30 degrees.

Figure 4 shows the stator 1 in two representations, one of the representations

Connecting means 3 reproduces in an exploded view, whereas in the second illustration the connecting means 3 are arranged in the middle receptacles 6. It can also be seen from FIG. 4 that each center receptacle 6 is formed on the outer surface 12 of the stator pack 13 of the stator 1, which consists of a stack of individual stator laminations 15 and extends radially outward on the stator 1. In particular, the representation in which the

Connecting means 3 are shown arranged in the middle receptacles 6, it can be seen that the middle receptacles 6 do not completely encircle the shaft 4 of the connecting means 3 in the circumferential direction, but with an angle greater than 180. In addition, the head 5 strikes the center mount 6.

FIG. 5 is again an individual representation of a bolt

Connection element 3 with the shaft 4 and the head 5 can be seen.

List of reference numerals stator

casing

Lanyard shaft

Head center shot

Stator bearing

End section

Partial cylinder

Partial hollow cylinder

Lateral surface

Stator package

Screw connection stator lamella centering and straightening rail

Claims

1. Positive stator suspension of a stator (1) in a stator (1)

accommodating housing (2), the non-rotatable form fit being formed by connecting means (3) inserted between the stator (1) and housing (2), for which purpose the connecting means (3) each having a shaft (4) and a head (5) in central receptacles (6) of the stator (1) are introduced and the stator (1) is suspended via the connecting means (3) in stator bearings (7) of the housing (2), characterized in that

A press connection between the respective stator bearing (7) and the head (5) and the stator bearing (7) and an end section (8) of the shaft (4) facing away from the head (5) of the connecting means (3) respectively arranged in the stator bearing (7) is present.

2. Stator suspension according to claim 1, characterized in that each stator bearing (7) has at least two sections, a first section as a partial cylinder (9) with a shaft receptacle (10) and a second section as a partial hollow cylinder which is not completely closed in the circumferential direction ( 11) is formed.

3. stator suspension according to claims 1 or 2, characterized in that the press connection of the end section (8) and stator bearing (7) between the shaft receptacle (10) of the stator bearing (7) and the end section (8) of the shaft (4) and

Press connection of head (5) and stator bearing (7) between the partial hollow cylinder (11) and the head (5) of the connecting means (3) are formed.

4. stator suspension according to at least one of the preceding claims, characterized

characterized in that the partial hollow cylinder (11) of the stator bearing (7) the central receptacle (6) and / or the head (5) of the connecting means (3) in the circumferential direction of the

Partial hollow cylinder (11) not completely, but encompasses at an angle greater than 180 degrees.

5. stator suspension according to at least one of the preceding claims, characterized

characterized in that the end section (8) of the shaft (4) corresponds to an overhang of the shaft (4) with respect to the central receptacle (6) and / or the head (5) on the

Center mount (6) strikes.

6. Stator suspension according to at least one of the preceding claims, characterized in that the end section (8) of the shaft (4) is longer than the head (5) of the connecting means (3).

7. stator suspension according to at least one of the preceding claims, characterized

characterized in that each center receptacle (6) is formed on the stator (1) by a circumferential surface (12) of a stator core (13) of the stator (1) extending radially outward.

8. stator suspension according to at least one of the preceding claims, characterized

characterized in that the central receptacle (6) does not completely surround the shaft (4) of the connecting means (3) in the circumferential direction, but at an angle greater than 180 degrees.

9. stator suspension according to at least one of the preceding claims, characterized

characterized in that for securing the stator (1) against axial displacement between the housing (2) and the stator (1) and / or connecting means (3) there is an additional securing connection acting in the axial direction, the securing connection being provided on the heads by way of a housing insert (5) the connecting means (3) and / or the stator (1) acting blocking device is realized.

10. stator suspension according to at least one of the preceding claims, characterized

characterized in that for securing the stator (1) against axial displacement between the housing (2) and the stator (1) and / or connecting means (3) there is an additional securing connection acting in the axial direction, the securing connection being provided by an axial screw connection (14 ) between the housing (2) and shaft (4) of the connecting means (3).