DE102011119603B4 - Electric motor - Google Patents

Abstract

Electric motor, the rotor shaft (6) of the electric motor being mounted in a first bearing plate (4) via a first bearing (5), the rotor shaft (6) of the electric motor being mounted in a second bearing plate (1) via a second bearing (9) The stator core (7) with stator winding is received in a stator housing (2), the stator housing (2) being manufactured as a continuously cast part, in particular an aluminum continuous cast part, characterized in that the continuously cast part has at least one flat connection surface, the extent of which is transverse to the continuous casting direction is greater than the largest diameter of the stator core (7) or the stator winding, with at least two circumferentially spaced thickenings on the continuous casting being provided to form the flat connection surface, each of which includes at least one cooling channel (3).

Description

Description:

The invention relates to an electric motor.

It is generally known to mount the rotor, that is to say the rotor shaft, of the motor via a bearing in a bearing plate which is connected to the motor housing.

From the DE 10 2009 001 942 A1 a housing of an electrical machine is known as the closest prior art.

From the DE 299 04 809 U1 an electric motor with liquid cooling is known.

From the DE 10 2010 050 348 A1 a method for manufacturing an electric motor is known.

From the DE 694 10 822 T2 a method for manufacturing a stator for a rotating electrical machine is known.

From the DE 10 2008 033 601 A1 an electric motor is known.

From the DE 20 2007 016 431 U1 an adapter plate for a rotating electrical machine with a cast housing is known.

From the DE 102 51 411 A1 an apparatus comprising a semiconductor module and a heat sink is known.

From the DE 74 24 640 U an electric motor with additional parts attached to the periphery of the motor housing is known.

From the DE 36 25 661 A1 an electric motor is known.

The invention is therefore based on the object of developing an electric motor that is easy to manufacture.

According to the invention, the object is achieved in the case of the electric motor according to the features specified in claim 1.

Important features of the invention in the case of the electric motor are that the rotor shaft of the electric motor is supported by a first bearing in a first end shield,
wherein the rotor shaft of the electric motor is mounted in a second bearing plate via a second bearing,
wherein the stator core with stator winding is received in a stator housing,
wherein the stator housing is manufactured as a continuously cast part, in particular an aluminum continuously cast part.

The advantage here is that simple production of the stator housing can be achieved. In addition, a series of many engine variants can be produced using only a small number of parts. The construction kit from which the variants of the series are manufactured therefore has a small number of parts. In particular, the same end shields and bearings can be used in all variants. In addition, the stator housing is only produced in the length associated with the respective variant, in particular cut from the continuous casting.

A high variance can thus be generated in a simple manner, that is to say motors with different maximum output torques can be generated in a less expensive manner.

In an advantageous embodiment, the continuously cast part has cooling channels through which the cooling medium can flow. The advantage here is that improved cooling can be achieved and the dissipated heat can even be used for heating a passenger compartment area. In addition, the occurrence of thermal hotspots is avoided, since the cooling medium flows through not only the stator housing but also the end shields and thus brings about thermal compensation between the individual areas of the motor housing.

In an advantageous embodiment, the stator housing is arranged between the first and second end shields. The advantage here is that the end shields not only close the stator housing to form the housing, but also the interconnection of the cooling channels and thus also the distribution of the cooling medium is carried out by means of the end shields.

In an advantageous embodiment, the cooling channels open into a respective recess arranged in the side of the respective end shield facing the stator housing,

In particular, each cooling channel opens at its first axial end into a recess in the first bearing plate, which forms a collecting space area between the first bearing plate and stator housing, and each cooling channel opens at its second axial end into a recess in the second bearing plate, which forms a collecting space area between the second bearing plate and stator housing forms. The advantage here is that the end shields can be made essentially round and have to have a diameter that is only slightly larger than the hollow cylindrical base body of the continuously cast part which surrounds the stator. The wall thickness of the base body is thin executed. The flat connection surfaces are then formed by thin-walled thickenings on the circumference of the continuously cast part, that is to say the stator housing.

In an advantageous embodiment, the first and second bearing plates are made of aluminum or steel.

In an advantageous embodiment, the stator, that is to say in particular the stator core with stator winding, is cast in the stator housing by means of potting compound.

According to the invention, the continuously cast part has at least one flat connection surface, the extent of which transversely to the continuous casting direction is greater than the largest diameter of the laminated stator core or the stator winding.

According to the invention, at least two thickenings which are spaced apart from one another in the circumferential direction and which each comprise at least one cooling channel are provided to form the flat connection surface.

In an advantageous embodiment, a module housing part is placed on the flat connection surface.

In an advantageous embodiment, the module housing part is positively connected in that it is pressed towards the motor by a screw head of a screw and is fixed to a recess, in particular a groove, of the continuously cast part by means of a fastening plate with a projection or a screw hook part,
wherein the screw is at least partially screwed into the mounting plate or the screw hook.

In an advantageous embodiment, the module housing part is pressed against the continuously cast part by means of a clamp, in that the clamp engages behind a recess, in particular a groove, formed in a thickening,

in particular wherein the clamp engages behind with a first leg of the clamp in a first recess of a thickening and with a second leg of the clamp in a second recess, the first and second recess being spaced from one another in the circumferential direction,

in particular wherein the opening of the respective recess is directed towards the stator and the respective thickening extends from the base body of the continuously cast part in the radial direction outward, in particular wherein the base body is a hollow cylinder.

In an advantageous embodiment, the projection of the fastening plate extends away from the stator.

In an advantageous embodiment, heat-conducting paste is arranged between the module housing part and the continuously cast part.

In an advantageous embodiment, the module housing part comprises a cooler arrangement, an oil pump arrangement, a heat pump arrangement or an electronic circuit.

In an advantageous embodiment, the flat connection surface is roughened, in particular by means of sandblasting.

Further advantages result from the subclaims.

• In der 1 ist ein erfindungsgemäßes Ausführungsbeispiel in Schnittansicht gezeigt.
• In der 2 ist eine zugehörige Schrägansicht gezeigt.
• In der 3 ist eine zugehörige Draufsicht gezeigt.
• In der 4 ist ein vergrößerter Ausschnitt eines Querschnitts gezeigt, dessen Schnittebene in 1 mit B gekennzeichnet ist.

The invention will now be explained in more detail with reference to figures:

• In the 1 an embodiment of the invention is shown in sectional view.
• In the 2 an associated oblique view is shown.
• In the 3 a corresponding plan view is shown.
• In the 4th an enlarged detail of a cross-section is shown, the cutting plane of which in FIG 1 marked with B.

As shown in the figures, the electric motor according to the invention has a rotor shaft 6th on which one has a camp 5 in a bearing shield 4th is stored, which is arranged on the output side and via a bearing 9 in a bearing shield 1 , which is arranged at the other axial end region.

The stator of the electric motor has a laminated stator core 7th with a stator winding, in particular with a stator winding cast by means of potting compound, which is in a stator housing part 2 is arranged. A good heat transfer to the stator housing part is achieved by means of the potting compound 2 achievable because the potting compound can be implemented as a heat-conducting potting compound. The heat transfer resistance between the stator winding and the stator housing part 2 is thus reducible.

The stator housing part can be manufactured as a continuously cast part, in particular an aluminum continuously cast part. Thus, not only the winding wires made of copper in the stator winding, but also the potting compound and the material of the continuously cast part can be made as a good heat conductor. In addition, simple production can be achieved.

Another advantage is that a series of motors which has a high degree of variance, that is to say comprises many motor variants, can be produced in a simple manner, that is to say with a small number of parts. This is because the continuously cast part can be easily produced with different lengths, so that rotors and stators of different lengths can be assigned accordingly, but always the same end shields ( 1 , 4th ) and warehouse ( 5 , 9 ) can be used. This means that engine variants can be produced with just a few parts that can generate different maximum or nominal torques.

The continuously cast profile of the continuously cast part, i.e. the stator housing part 2 , has not only a large central recess for receiving the stator, but also further recesses, which act as cooling channels 3 are used.

In this case, at least one or two flat connection surfaces are placed on the outside of the stator housing part 2 shaped so that the motor can be attached to a flat, planar interface on an underside. A module housing part is located on a further flat connection surface 8th attachable. The two connection surfaces are preferably arranged in parallel.

In order to accommodate the stator, the continuously cast part is shaped essentially like a hollow cylinder. In order to also form the parallel connection surfaces, the continuously cast part has four corner areas, one of these corner areas in FIG 4th can be seen in cross section.

The hollow cylinder is thus formed with thickenings at four points on the circumference, which form the corner areas. There are cooling channels in each of these corner areas 3 arranged.

In addition, the module housing part 8th placed on one of the flat connection surfaces and positively connected to the stator housing part. For this purpose there is a screw through each recess 10 carried out, which with its threaded area in a mounting plate 40 is screwed in. The mounting plate 40 has a projection, in particular a nose-like projection. The lead 40 engages in a recess formed on the stator housing part. By means of this head start 40 a form-fitting connection can thus be achieved. The protrusion rises on the mounting plate 40 opposite parallel to the screw axis direction, i.e. to the module housing part 8th down. The module housing part 8th so is between the screw head of the screw 10 and the lead 40 held and limited. The screw head is on the side of the module housing part facing away from the stator 8th arranged. The recess is provided in the corner area protruding tangentially on the hollow cylinder and is advantageously designed like an undercut.

In particular, the module housing part is fastened to the stator housing by means of screw hooks which engage in a groove on the stator housing.

In this way is the module housing part 8th on the stator housing 2 can be fastened without the stator housing manufactured as a continuously cast part 2 would have to be reworked.

In addition, the wall thickness of the continuously cast part can be selected to be very thin. Likewise are the cooling channels 3 comprehensive corner areas with thin walls. The introduction of threaded bores for receiving a fastening screw for the module housing part 8th is therefore avoidable.

The module housing part 8th is thermally conductively connected to the stator housing at the flat connection surface. Thermally conductive paste is preferably applied to the flat connection surface and thus between the module housing part 8th and stator housing 2 arranged.

The interconnection of the cooling channels 3 takes place by means of the end shields ( 1 , 4th ). The end shields ( 1 , 4th ) on their stator housing 2 facing sides each have a recess, in particular a groove, in particular an annular groove running around in the circumferential direction, into which the respective end regions of the respective cooling channel 3 flow out. That in the cooling channels 3 arranged cooling medium is driven convectively, so not actively by a pump.

In a further exemplary embodiment according to the invention, the cooling medium is passed through an outside of the stator housing 2 arranged pump.

The module housing part 8th comprises an electronic circuit, a heat pump arrangement and / or an oil cooler arrangement or a heat exchanger arrangement. Thus, heat from the engine is via the engine housing part 8th can be transferred to this arrangement and thus the cooling of the engine can be improved. In addition, it is possible to warm up a medium moving in the arrangement and thus to heat up another area of the room, for example the interior of an electric vehicle when the motor is the drive motor of the electric vehicle.

When using an oil cooler arrangement, the module housing is part 8th a cooling medium, in particular oil, flows through it, so that the from the motor to the module housing part 8th inflowing heat is given off to the cooling medium and is preferably transported further by this to a heat sink, which gives off the heat to the environment.

The respective end shield can also be referred to as a flange part or a bearing flange or a bearing flange part.

The end shields are preferably screw-connected to the stator housing, in particular by means of tie rods, which each protrude through both end shields and the stator housing, and associated nuts.

In a further exemplary embodiment according to the invention, instead of the aforementioned form-fitting connection of the module housing part 8th with the stator housing 2 a clamp used which engages in at least one or two recesses of the corner areas and the module housing part 8th to the stator housing 2 presses.

List of reference symbols

1

End shield, B-side

2

Stator housing

3

Cooling duct

4th

End shield, A-side, i.e. output side

5

warehouse

6th

Rotor shaft

7th

Laminated stator core with stator winding, in particular with a stator winding encapsulated by means of casting compound

8th

Module housing part

9

warehouse

10

screw

40

Fastening plate with a projection, in particular with a nose

Claims (13)

Electric motor, the rotor shaft (6) of the electric motor being mounted in a first bearing plate (4) via a first bearing (5), the rotor shaft (6) of the electric motor being mounted in a second bearing plate (1) via a second bearing (9) The stator core (7) with stator winding is received in a stator housing (2), the stator housing (2) being manufactured as a continuously cast part, in particular an aluminum continuously cast part, characterized in that the continuously cast part has at least one flat connection surface, the extent of which is larger than the largest diameter of the stator core (7) or the stator winding transversely to the continuous casting direction, with at least two circumferentially spaced thickenings on the continuous casting being provided to form the flat connection surface, each of which includes at least one cooling channel (3). Electric motor after Claim 1 , characterized in that the continuously cast part has cooling channels (3) for the cooling medium to flow through. Electric motor according to at least one of the preceding claims, characterized in that the stator housing (2) is arranged between the first and second end shields (1, 4). Electric motor according to at least one of the preceding claims, characterized in that the cooling channels (3) open into a respective recess arranged in the side of the respective bearing plate (1, 4) facing the stator housing (2), in particular each cooling channel (3 ) at its first axial end opens into a recess in the first end shield (4), which forms a collecting space between the first end shield (4) and stator housing (2), and each cooling channel (3) at its second axial end into a recess in the second end shield (1) opens, which forms a collecting space area between the second end shield (1) and stator housing (2). Electric motor according to at least one of the preceding claims, characterized in that the first and second bearing plate (1, 4) are made of aluminum or steel. Electric motor according to at least one of the preceding claims, characterized in that the stator, in particular the stator core (7) with stator winding, is cast in the stator housing (2) by means of potting compound. Electric motor according to at least one of the preceding claims, characterized in that a module housing part (8) is placed on the flat connection surface. Electric motor after Claim 7 , characterized in that the module housing part (8) is positively connected by being pressed towards the motor by a screw head of a screw (10) and by means of a fastening plate (40) with a projection or a screw hook part on a recess, in particular a groove, of the cast part is wherein the screw (10) is at least partially screwed into the fastening plate (40) or the screw hook. Electric motor after Claim 7 , characterized in that the module housing part (8) is pressed against the extruded part by means of a clamp, in that the clamp engages behind a recess, in particular a groove, formed in a thickening, in particular the clamp with a first leg of the clamp in a first recess a thickening and with a second leg of the clamp engages behind in a second recess, the first and the second recess being spaced from one another in the circumferential direction, in particular wherein the opening of the respective recess is directed towards the stator and the respective thickening extends from the base body of the continuously cast part in a radial direction Extends outward direction, in particular wherein the base body is a hollow cylinder. Electric motor after Claim 8 , characterized in that the projection of the mounting plate (40) extends away from the stator. Electric motor according to one of the Claims 7 to 10 , characterized in that heat-conducting paste is arranged between the module housing part (8) and the continuously cast part. Electric motor according to one of the Claims 7 to 11 , characterized in that the module housing part (8) comprises a cooler arrangement, an oil pump arrangement, a heat pump arrangement or an electronic circuit. Electric motor according to at least one of the preceding claims, characterized in that the flat connection surface is roughened, in particular by means of sandblasting.

Images