DE102011079156A1 - Pre-assembly module i.e. operational plug, for producing e.g. main rotational torque in electromotive drive unit of powertrain of person motor car, has cooling ring in which rotor shaft component is rotatably mounted through bearings - Google Patents

Abstract

The module has front and rear bearing plates (12, 13) carrying respective bearings (18) for supporting a rotor shaft component (4) of an electromotor (2) that is provided with a stator (5). The front and rear bearing plates are connected together at an interposition of a cooling ring (9) in order to form a support structure (28), so that the stator is accommodated in the cooling ring and arranged in the support structure. The rotor shaft component is designed as a sleeve shaft component and rotatably mounted in the cooling ring over the bearings. An independent claim is also included for a method for assembling a pre-assembly module.

Description

The invention relates to a preassembly module for an electromotive transmission device with a stator of an electric motor, with a rotor assembly of the electric motor, with a front and a rear bearing plate bearing bearings for supporting the rotor assembly. The invention also relates to an electromotive transmission device with the preassembly module and to a method for assembling the preassembly module.

Electric motors are used in the drive train of vehicles, which generate depending on the drive concept only the drive torque or an auxiliary drive torque in the drive train of the vehicle. For this purpose, the electric motors are usually coupled with transmission devices.

For example, the document discloses DE 198 411 59 A1 a drive unit for a motor vehicle with an electric motor which is operatively connected via at least one downstream, drive shafts comprehensive, differential gear with drive wheels of the motor vehicle. The electric motor is arranged coaxially with the drive shaft in this embodiment.

In addition to the actual function of the electric motors in operation, the usual considerations regarding the production costs and manufacturing possibilities. Thus, it is also desirable in electric motors to manufacture them as inexpensively as possible and to be able to integrate in a simple manner in the vehicle or in the transmission device.

From another area of technology is the publication EP 1 609 228 B1 known, which describes an electric machine with rotor bearing integrated in the stator. In this electric motor stator and rotor are enclosed by a common housing. The rotor is supported by bearings, whose outer rings engage directly in the stator, so that the rotor is mounted in the housing via the stator. It is emphasized that this electric machine already forms its own assembly unit, which allows a check of the air gap between the stator and rotor by free-wheeling of the rotor shaft before closing the housing within the manufacturing process of an electric machine.

Field of the invention

The invention has for its object to propose an improvement for an electromotive transmission device. This object is achieved by a pre-assembly module having the features of claim 1. The independent claims 8 and 9 relate to an electromotive transmission device with the preassembly module and a method for mounting the preassembly module. Preferred or advantageous embodiments of the invention are disclosed in the subclaims, the following description and the figures.

The invention relates to a pre-assembly module which is suitable and / or designed for an electromotive transmission device. The electromotive transmission device will be described in conjunction with independent claim 8.

The pre-assembly module includes an electric motor having a stator and a rotor shaft assembly. The stator has, in a preferred constructional realization, a plurality of stator laminations and optionally also coils. The rotor shaft assembly includes a rotor which is coaxial and concentric with the stator. In a particularly preferred structural embodiment, the rotor shaft assembly comprises a rotor shaft, which is rotatably coupled to the rotor and which is arranged coaxially and / or concentrically with the rotor and the stator. Particularly preferably, the rotor shaft is designed as a hollow shaft through which a further shaft, for example an output shaft, can be performed.

The pre-assembly module comprises a front and a rear bearing plate, which bearing, in particular rotor bearing, for supporting the rotor shaft assembly wear. The bearings can in principle be of any desired design, for example as plain bearings, but it is preferred that the bearings are realized as roller bearings. For storage in each case a bearing ring of the bearing is rotatably connected to the bearing plate and the other bearing ring rotatably connected to the rotor shaft assembly.

In the context of the invention, it is proposed to use a cooling ring in the pre-assembly module, which serves as a basic function for regulating the temperature of the electric motor. The cooling ring is preferably arranged circumferentially around the stator. Particularly preferably, the cooling ring is sleeve-shaped in the region of the stator, wherein the cooling ring extends in the axial direction, in particular over the entire length of the stator. The cooling ring is arranged coaxially to the stator-rotor shaft assembly and possibly to the hollow shaft.

As an additional function, the cooling ring has a supporting function, wherein the front, the rear bearing plate with the interposition of the cooling ring are connected to each other so that a support structure is formed. In this support structure is the stator preferably firmly received and the rotor shaft assembly rotatably supported by the bearing. Thus, the rotor shaft assembly and kinematically parallel to the stator are mounted in the support structure.

The dual function of the cooling ring allows a compact yet stable design of the pre-assembly module. In particular, the cooling ring assumes the function of a supporting housing. The cooling ring may be formed in one or more pieces.

The pre-assembly module is designed as a preferably operational plug-in for the transmission device, wherein the stator and rotor assembly are already firmly positioned in the pre-assembly module to each other and are rotatably mounted to each other. This solution results in a high dimensional stability in terms of concentricity and of any angular errors of the rotor shaft assembly relative to the surrounding stator. The pre-assembly module is self-holding and can be tested for functionality in preferred embodiments prior to integration into the transmission device.

The assembly or disassembly of the preassembly module in the transmission device is very simple, since the preassembly module with mutually adjusted stator and rotor shaft assembly can be used as a whole and taken out again.

In the possible embodiment of the invention, in which the rotor shaft assembly is designed as a hollow shaft assembly and / or provided as a hollow shaft rotor shaft, the preassembly module, in particular the stator and the rotor shaft assembly, coaxial and / or concentric with the hollow shaft. This structural design allows a very compact design of the pre-assembly and thus a simplified integration of the pre-assembly in the transmission device. Particularly preferably, a coupling structure is arranged in the hollow shaft, for example, a spline to couple a second shaft inserted into the hollow shaft in the direction of rotation about a common axis of rotation.

In a possible development of the invention it is provided that the rear bearing plate is integrally connected to the cooling ring. This embodiment is also based on the consideration that it is possible to mount the pre-assembly module only from one end face. The advantage is that the cohesive connection and thus the relative positioning between the rear end plate and the cooling ring can be done for example in a separate clamping. This ensures that a defined by the rear bearing plate rotor bearing is aligned with high precision to the cooling ring, which forms part of the support structure.

In a preferred embodiment of the invention, the rear end plate and the cooling ring are welded together. The cohesive connection, in particular the welding, requires - compared to a screw, for example - only a very small space, again - compared to the example of the screw - no threaded holes for screws, etc. must be provided, which usually has a large axial Take up space. In addition, the cohesive connection, in particular the welded joint, high load capacity. Particularly preferably, the welded joint is implemented by a laser welding process, which is characterized in that the combination cooling ring and rear end shield is heated only locally in the region of the welded joint and thus does not distort or only negligibly. In addition, the weld is tight, d. H. The engine does not have to be sealed separately against lubricants, especially gear oil.

Particularly preferably, the rear end plate is formed as a forming part, in particular as a deep-drawn part. Such a realized rear end shield is characterized on the one hand by low production costs, on the other hand in large-scale production by low manufacturing tolerances.

In a preferred embodiment of the invention, the stator assembly is arranged in the support structure potted. By casting the stator in the support structure, this is finally defined in the position. Particularly preferably, the stator is encapsulated in the previously described combination rear bearing plate - cooling ring, so that a large-area fixation of the stator is achieved.

In a preferred embodiment of the invention, the front bearing plate is coupled via a detachable connection with the cooling ring. On the one hand, it is possible for the front end shield to be coupled directly to the cooling ring via a screw connection. In modified embodiments can also be provided that the front bearing plate is indirectly coupled with the interposition of intermediate elements with the cooling ring. For example, it has been shown that it may be advantageous to set between the front bearing plate and the cooling ring still a coupling ring for supplying the power supply for the electric motor.

In a possible structural realization of the invention are on the one-piece or multi-piece cooling ring mounting areas, such as tabs with threaded holes for Screw connections for indirect or direct coupling with the front bearing plate provided. The detachable connection ensures that after joining the rear end shield and the cooling ring, inserting the stator and the rotor shaft assembly, the front end plate can be placed and coupled to the cooling ring to complete the pre-assembly.

In a preferred embodiment of the invention, the cooling ring on the outside on guide structures for a cooling fluid, wherein the guide structures are formed so that they form cooling channels together with a housing into which the pre-assembly is introduced. The separation surface between pre-assembly module and housing is thus used as a functional surface for the cooling channels. So it is particularly preferably provided that the cooling ring on the radial outside z. B. in the direction of rotation or helically extending webs, which bear against the radially inner surface of the housing, so that common cooling channels are formed between the webs, in which a cooling fluid, in particular oil or another cooling liquid, is passed through during operation. In particular, the cooling fluid directly contacts the housing and the cooling ring. Thus, the cooling ring and housing together form a cooling jacket for the electric motor.

Alternatively or additionally, it may be provided that the cooling ring on the outside seals, in particular the rotation axis circumferential seals or corresponding gaskets receptacles, wherein the seals are formed that they form a sealing area together with a housing or the housing into which the pre-assembly is introduced , Also in this development or alternative, the outer surface of the cooling ring is thus used as a functional surface, which occurs together with the inner surface of the housing - also as a functional surface - in operative connection.

Another object of the invention relates to an electromotive transmission device with a pre-assembly module, as described above or according to one of the preceding claims.

In the electromotive transmission apparatus, the electric motor of the pre-assembly module is for generating a drive torque for a vehicle. The drive torque may be configured as a main torque that exclusively drives the vehicle. However, the drive torque may also be configured as an assist torque or control torque that provides additional drive torque to the vehicle in addition to a main torque of another engine, optionally an electric motor or an internal combustion engine. Thus, the transmission device can be designed in particular as a so-called electrical axle, as an electric drive unit, as a hybrid transmission, as a superposition gear or as a differential gear. In the latter case, it can be provided that the drive torque of the electric motor is selectively transmitted to an axle or a wheel in order to improve the driving behavior of the vehicle. The vehicle is designed, for example, as a passenger vehicle, but in modified embodiments, it may also be a truck.

In particular, the electromotive transmission device to a housing or a corresponding housing portion, as has been previously described and in which the pre-assembly can be plugged in for easy assembly.

Another object of the invention relates to a method for assembling the preassembly module, wherein first the rotor shaft assembly and a stator assembly comprising the stator, the cooling ring and the rear end shield are mounted. The order of assembly of rotor shaft assembly and stator assembly is insignificant. Subsequently, the rotor shaft assembly is inserted into the stator assembly and sealed with the front end shield. Alternatively, the rotor shaft assembly is connected to the front end shield and then inserted into the stator assembly. In a next step, the pre-assembly module can be tested or - untested - used in the electromotive transmission device.

Further features, advantages and effects of the invention will become apparent preferred embodiments of the invention and the accompanying figures.

Showing:

1 a schematic longitudinal section through a transmission device as an embodiment of the invention;

2 a schematic three-dimensional representation of the pre-assembly in the 1 as an embodiment of the invention;

3 a schematic longitudinal sectional view of the pre-assembly in the 2 during assembly of three subassemblies;

4 a schematic block diagram of a vehicle with the transmission device of the preceding figures.

The 1 shows a portion of a transmission device 1 with an electric motor 2 for a vehicle in a schematic longitudinal section through an axis of rotation 3 of the electric motor 2 or the transmission device 1 , The transmission device 1 is designed as an electric motor drive unit and can, for. B. in the following variants, as in 4 is illustrated in a block diagram:
The 4 shows a vehicle 100 with four wheels 101 with the electromotive transmission device 1 , wherein the transmission device 1 the electric motor 2 and a gearbox 106 includes. In a training as an electrical axis 102 puts the gear device 1 the main drive torque for the axle of the vehicle 100 exclusively by the electric motor 2 to disposal. In a training as a superposition or hybrid transmission 103 is the transmission device 1 formed, the driving torque of the electric motor 2 another drive torque, for example, another electric motor or an internal combustion engine, in particular as an auxiliary drive torque or main drive torque to be superimposed. In the embodiment as an electric differential, the driving torque of the electric motor becomes 2 selectively associated with an output, wherein the electrical differential as a longitudinal differential 104 or an axle differential 105 can be trained. By the dashed line in the 10 is symbolized that only one or any combination of transmission devices 1 in the vehicle 100 can be integrated.

Like in the 1 is shown, the electric motor comprises 2 a rotor shaft assembly 4 and a stator 5 which is coaxial and concentric with a hollow shaft section 6 the rotor shaft assembly 4 in a housing 7 are arranged. Thus, the hollow shaft section 6 coaxial and concentric in the electric motor 2 arranged. The rotor shaft assembly 4 is rotatable about the axis of rotation 3 in the case 7 Stored arranged, the stator 5 is in relation to the housing 7 stationarily or stationarily positioned.

The housing 7 has a cylindrical section 8th on, in which the electric motor 2 with respect to the axial extent along the axis of rotation 3 at least for the most part is arranged. In the cylindrical section 8th is between the stator 5 and the housing 7 a cooling ring 9 which is also coaxial and concentric with the stator 5 , Rotor shaft assembly 4 or to the cylindrical portion 8th is arranged.

The cooling ring 9 is formed as a sleeve and has on its radial outer side a plurality of in the circumferential direction about the axis of rotation 3 running bridges 10 on which on the inner surface of the housing 7 in the cylindrical section 8th abut, so that between the webs 10 and thus between the case 7 and the cooling ring 9 cooling channels 11 are formed. In the cooling channels 11 can a medium, in particular fluid, for. As an oil or a coolant, for cooling the electric motor 2 be guided. The supply and removal of the fluid is in the 1 not shown. The cooling ring 9 and the housing are made of metal so that there is good thermal coupling with the fluid. On the radial inside, the cooling ring 9 a cylindrical surface. In the end areas is the cooling ring 9 opposite the housing 7 and the front end shield 12 sealed with gaskets. The cooling ring 9 includes a mounting flange 30 the one-piece on the cooling ring 9 formed or with this z. B. is integrally connected.

End is the electric motor 2 on the left with a front end shield 12 and on the right with a rear end shield 13 closed. Front end shield 12 and rear end shield 13 each include a nozzle section 14 . 15 which extends into the interior of the housing 7 extends and which one seat 16 . 17 for a rotor bearing 18 . 19 provides.

During operation, the rotor shaft assembly rotates 4 around the axis of rotation 3 and is about the rotor bearings 18 . 19 with interposition of the end shields 12 . 13 opposite the cooling ring 9 and over this opposite the housing 7 stored, with the rotor bearings 18 . 19 with their inner rings on the seats 16 . 17 arranged and rotatably with their outer rings with the rotor shaft assembly 3 are connected.

The rear end shield 13 is designed as a deep-drawn part and with the cooling ring 9 connected directly cohesively and forms a combination with this 20 out. The rear end shield 13 is as one around the axis of rotation 3 formed rotationally symmetrical component and has starting from the axis of rotation 3 first the nozzle section 15 for receiving the rotor bearing 17 on. At the neck section 15 closes a first annular disc area 21 and in the axial direction offset a second annular disc area 22 on, with the first annular disc area 21 via a connecting piece section 23 connected is. The rear end shield 13 abuts with a radially outer region of the second annular disc region 22 in the radial direction against a shoulder of the cooling ring 9 , so that an angled in longitudinal section contact surface 24 as a joining surface between the cooling ring 9 and end shield 13 results. This design makes the rear end plate 13 over the cooling ring 9 z. B. on the housing 7 supported. The cooling ring 9 and the bearing plate 13 are used as joining partners via a weld 25 in the area of the contact surface 24 connected as joining surface cohesively. The joining between cooling ring 9 and end shield 13 can be done for example in a separate clamping, as will be explained below. The stator 5 is in the electric motor 2 over end potting compounds 26 potted is arranged.

The front end shield 12 is against - with the interposition of a supply flange 27 or immediately - with the cooling ring 9 releasably connected, for example via a screw connection. This forms the front end shield 12 , the cooling ring 9 and the rear end shield 13 a self-supporting or self-supporting support structure 28 out, in which the stator 5 about the potting compounds 26 firmly arranged and the rotor shaft assembly 4 over the rotor bearings 18 . 19 is stored. In particular, the support structure 28 without the case 7 educated.

As can be seen in particular from the 2 which gives a three-dimensional view of the structure without housing 7 shows is the electric motor 2 as a self-holding pre-assembly module 29 designed as a ready-to-install unit in a simple manner in the housing 7 can be inserted.

By execution as a pre-assembly module 29 can the electric motor 2 before installation in the housing 7 For example, be subjected to a test run because of the support structure 28 the relative positioning of stator 5 and rotor shaft assembly 4 without interposition of the housing 7 already finalized. Depending on the embodiment, the housing 7 exclusively for the electric motor 2 or the pre-assembly module 29 be dimensioned or a housing portion of a larger housing structure of the transmission device 1 form, for example, in the 1 on the right side further components in the housing 7 connect. In particular, in the latter constellation, it is a further advantage that the electric motor 2 not in the case 7 is composed, but first as a pre-assembly module 29 ready pre-assembled and tested and then only in the housing 7 is used.

This assembly order also has advantages in disassembly or repair of the transmission device 1 , Again, it is possible to use the electric motor 2 as pre-assembly module 29 as a whole out of the case 7 pull out and through another pre-assembly module 29 to replace or independent of the transmission device 1 to test and repair.

In the 3 is highly schematized the assembly of the pre-assembly module 29 shown. On the right side is the combination 20 comprising the cooling ring 9 and the rear end shield 13 , with already potted stator 5 to recognize. Likewise, in this subassembly already the supply flange 27 placed. In this subassembly is hereinafter the rotor shaft assembly 4 inserted. The rotor shaft assembly includes the rotor, the rotor carrier and the rotor bearings 18 . 19 , During assembly, the rotor shaft assembly becomes 4 on the neck section 15 the rear end shield 13 postponed. In a next step, the electric motor 2 by inserting the front bearing plate 12 closed. This is the nozzle section 14 in the rotor bearing 17 retracted. Below is the cut 14 in the rotor bearing 17 retracted. Below is the front end shield 12 with the cooling ring 9 detachably connected via a screw connection. It is also conceivable that the rotor shaft assembly 4 first on the front bearing plate 12 is placed and this subassembly below in the combination 20 with the stator 5 is used.

After the rotor bearing 17 over the front bearing plate 12 on the cooling ring 9 is supported, and the rotor bearing 18 over the rear end shield 13 also on the cooling ring 9 are supported, are cooling ring 9 and rotor bearings 18 . 19 positioned very precisely to each other. After the stator 5 also on the cooling ring 9 is supported by the support structure 28 also the relative position between stator 5 and rotor shaft assembly 4 defined with a very short tolerance chain.

LIST OF REFERENCE NUMBERS

1

transmission device

2

electric motor

3

axis of rotation

4

Rotor shaft assembly

5

stator

6

Hollow shaft section

7

casing

8th

cylindrical section

9

cooling ring

10

Stege

11

cooling channels

12

(front) end shield

13

(rear) bearing plate

14

union section

15

union section

16

Seat

17

Seat

18

rotor bearing

19

rotor bearing

20

module

21

first annular disc area

22

second annular disc area

23

Connection nipple portion

24

contact surface

25

Weld

26

encapsulants

27

Versorgungsflansch

28

supporting structure

29

Vormontagemodul

30

mounting flange

100

vehicle

101

bikes

102

electrical axis

103

Superposition gearbox or hybrid transmission

104

longitudinal differential

105

axle differential

106

transmission

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 19841159 A1 [0003]
• EP 1609228 B1 [0005]

Claims (10)

Pre-assembly module ( 29 ) for an electromotive transmission device ( 1 ), with a stator ( 5 ) of an electric motor ( 2 ), with a rotor shaft assembly ( 4 ) of the electric motor ( 2 ), with a front and a rear end shield ( 12 . 13 ), camps ( 18 . 19 ) for supporting the rotor shaft assembly ( 4 ), characterized by a cooling ring ( 9 ), with the front, the rear end shield ( 12 . 13 ) with interposition of the cooling ring ( 9 ) are connected together to form a support structure ( 20 ), in which the stator ( 5 ) and in which the rotor shaft assembly ( 4 ) about the bearings ( 18 . 19 ) is rotatably mounted. Pre-assembly module ( 29 ) according to claim 1, characterized in that the rotor shaft assembly ( 4 ) is formed as a hollow shaft assembly. Pre-assembly module ( 29 ) according to claim 1 or 2, characterized in that the rear end shield ( 13 ) with the cooling ring ( 9 ) is integrally connected. Pre-assembly module ( 29 ) according to one of the preceding claims, characterized in that the stator ( 5 ) in the supporting structure ( 20 ) is arranged potted. Pre-assembly module ( 29 ) according to one of the preceding claims, characterized in that the front end shield ( 12 ) via a detachable connection with the cooling ring ( 9 ) is coupled. Pre-assembly module ( 29 ) according to one of the preceding claims, characterized in that the cooling ring ( 9 ) outside management structures ( 10 ) for a cooling fluid, wherein the guide structures ( 10 ) are formed so that these together with a housing ( 7 ) into which the pre-assembly module ( 29 ), cooling channels ( 11 ) form. Pre-assembly module ( 29 ) according to one of the preceding claims, characterized in that the cooling ring ( 9 ) has seals on the outside, wherein the seals are formed such that these together with one or the housing ( 7 ) into which the pre-assembly module ( 29 ), form a sealing area. Electromotive gear device ( 1 ) with a pre-assembly module ( 29 ) according to any one of the preceding claims. Method for assembling the pre-assembly module ( 29 ), where first the rotor shaft assembly ( 4 ) and a stator assembly comprising the stator ( 5 ), the cooling ring ( 9 ) and the rear end plate ( 13 ), hereinafter the rotor shaft assembly ( 4 ) is inserted into the stator assembly and with the front end shield ( 12 ) is closed and / or the front end plate ( 12 ) on the rotor shaft assembly ( 4 ) and this subassembly is inserted into the stator assembly. Method according to claim 9, characterized by a test step, wherein the pre-assembly module ( 29 ) without housing ( 7 ) is put into operation on a trial basis.

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