DE102009001942A1 - Housing for sealed electrical machine utilized e.g. as motor in steering system of motor vehicle, has base forming axial catch for bearing receptacle with bearing shield, where housing is manufactured by impact extrusion process - Google Patents

Abstract

The housing (2) has a base (3) which forms an axial catch for a bearing receptacle (4) with a bearing shield (7), where the housing is manufactured by forward impact extrusion process, backward forward impact extrusion process or forward and backward impact extrusion process using aluminum forging alloy. The housing receives an armature shaft (10) and a stator (12), where the armature shaft is rotatably supported in bearings (15, 16). The housing forms a heat sink for an electrical machine (1). An independent claim is also included for an electrical machine comprising bearings.

Description

The The invention relates to a housing of an electrical machine and an electric machine with such a housing.

such Housing of electrical machines, such as motors and / or generators are well known. Such electrical Machines are used, for example, in motor vehicle equipment, such as motors in servo drives, windscreen wiper drives and the like used.

Such Electric machines are in many applications extreme environmental conditions, such as for example, high temperatures and high temperature differences, high humidity, spray, dust, salt and the like exposed and therefore require a corresponding tightness and corrosion resistance.

1 shows a known electric machine 1 in an embodiment as a motor with a housing 2 in which an armature shaft 10 with a rotor 11 over camp 15 . 16 is rotatably mounted. A bearing flange 8th forms the so-called A-shield on the output side of the electric machine. This output side is here as a front end 6 designated. The bearing flange 8th is with a camp recording 4 for receiving a front bearing 15 Mistake. The bearing flange 8th is with the front end of the cylindrical housing 2 screwed by thread. An O-ring 8th seals the interior of the housing 2 towards the environment at this junction. The housing 2 has at its rear axial end 6 a rear bearing mount 17 for a rear warehouse 16 on. The rear bearing mount 17 is as a rear, inside the case 2 formed einogener end shield. Both bearings 15 . 16 are provided with appropriate axial seals.

The housing 2 and the bearing flange 8th form here a two-piece motor housing. The housing 2 is usually made of aluminum (Al) die casting or Al continuous casting, with the bearing flange usually made of Al diecasting. Al die casting is a die casting process in which aluminum in the liquid or doughy state is pressed under high pressure into a preheated steel mold. The applied pressure remains effective during solidification. The steel mold is the negative of the casting to be produced by the shrinkage dimension. Therefore, die-cast alloys must have a good mold filling capacity and low shrinkage. Castability and meltability of an Al casting alloy are dependent on the alloying ingredients, for example, additives to increase the castability and meltability may decrease the corrosion resistance.

Al-cast may be due to the production of voids due to the manufacturing process only limited pressure-tight. Especially in applications where very high leakage requirements in the foreground is therefore an additional material test what is directly associated with additional costs. The component costs are thus caused by the high tooling costs (in particular Follow-on tools) because of lower number of application high. This is the case in particular for one-piece housings. therefore, because of high complexity of the tools and component usually the two-part version with housing and separate Bearing flange may be necessary.

Also Manufacturing to an exact size is designed for Al die castings difficult and is therefore also considerable Associated production costs.

In front In this background, the present invention has the object underlying a housing for an electric machine to improve.

According to the invention This object is achieved by a housing having the features of the patent claim 1 and / or by an electric machine with the features of Patent claim 6 solved.

• – Ein Gehäuse einer elektrischen Maschine, bei welchem das Gehäuse mittels eines Fließpressverfahrens hergestellt ist.
• – Weiterhin wird eine elektrische Maschine mit einem Gehäuse zur Aufnahme einer in Lagern drehbar gelagerten Ankerwelle und eines Stators bereitgestellt, bei welcher das Gehäuse mittels eines Fließpressverfahrens hergestellt ist.

Accordingly, it is provided:

• - A housing of an electric machine, wherein the housing is made by means of an extrusion molding process.
• - Furthermore, an electric machine is provided with a housing for receiving a rotatably mounted in bearings armature shaft and a stator, wherein the housing is made by means of an extrusion process.

The The idea underlying the present invention is that the housing of an electrical machine not in conventional Way to produce by Al-die casting, but this now at least partially to use an Al extrusion molding process. The particular advantage is that the desired Pressure tightness due to the production already by the extrusion process by the associated massive forming of an aluminum Gutzens is reached. Due to the associated lamellar orientation The microstructure is very homogeneous and void-free. Subsequent testing for voids can be omitted.

An extrusion molding process is a massive forming at room temperature for the production of solid and hollow bodies. It is a puffing method after DIN 8583 in which one Workpiece is pressed by a ram through a nozzle (press sleeve). The shape of the workpiece to be produced results from the shape of the press ram and the press ram. Since the yield strength of the material must be exceeded, high pressures are necessary. During forward flow pressing, punch and workpiece movement are in the same direction, while reverse extrusion they are in opposite directions.

The Housing is preferably made of an aluminum wrought alloy.

A Aluminum alloy is referred to as aluminum wrought alloy when It is mainly processed by forming (rolling, pressing).

By the very high Reinalumimiumanteil the wrought alloys is the corrosion resistance previously used aluminum die-cast housings considerably improved.

Of the high pure aluminum content offers another advantage in the opposite improved conventional die-cast aluminum housings Thermal conductivity. Thus, the housing as a heat sink for the electric machine better be used and, for example, as a heat sink in the power loss analysis of a control / switching unit of electric machine to be involved. This results in a significantly cost-optimized overall system.

One Another advantage is that a production by means of extrusion molding as massive forming no undesirable texture results.

advantageous Refinements and developments of the invention will become apparent the dependent claims and from the description in synopsis with the figures of the drawing.

By a combination of the extrusion process, which one Forward, backward or combined Extrusion process can be, as well as the use of a Al-wrought alloy are the requirements pressure tightness, corrosion resistance and achieved good thermal conductivity at the same time.

Furthermore Preferably, an axial end of the housing with a Be provided bottom, which is a stop for a separate End shield forms.

alternative is it possible for the floor to be stocked is provided and forms a bearing plate. Thus, housing is and end shield integral with each other and the bearing support connected, reducing the total number of parts needed in a simplified manufacturing manner and in particular in With a view to reducing costs. Also reduce thereby an assembly time and thus the installation effort.

The electric machine can be used with any engine and especially at Electric motors and / or generators are used. she can Also designed as a sealed machine or the like be.

The Housing described above is especially for electrical Suitable for use in a motor vehicle, For example, as a power steering (steering systems, steering gear) and / or Windscreen wiper drive, are provided. This housing can but also use with all rotating electrical machines be used with any purpose.

The above embodiments and refinements of the invention leave also in any suitable way with each other combine.

The The present invention is described below with reference to the schematic Figures of the drawing specified embodiments explained in more detail. It shows:

1 a sectional view of an electrical machine according to the prior art;

2 a sectional view of a first embodiment of an electric machine according to the invention;

3 a sectional view of a second embodiment of the electric machine according to the invention; and

4 an exploded perspective view of the second embodiment according to 3 in Teilachnittansiccht.

In The figures of the drawing are identical and functionally identical elements and features - unless otherwise stated is - provided with the same reference numerals.

In 2 is a sectional view of a first embodiment of an electric machine according to the invention 1 shown.

A housing 2 is as a cylindrical body with a front axial end 6 and a rear axial end 5 and with a floor 3 produced by means of an extrusion process from a slug made of an aluminum wrought alloy. The floor 3 is on as an inner circumferential annular edge the front axial end 6 of the housing 2 trained and serves as an axial stop for a front bearing plate 7 , also referred to as A-end shield, inside the housing 2 on the ground 3 axially tight and against the inner wall of the housing 2 inside radially attached tightly. The front end shield 7 can with the case 2 be tightly connected in various ways, such as by welding (friction welding), gluing, pressing and the like.

The front end shield 7 has a bearing receiver 4 for a front camp 15 for a rotatable armature shaft 10 on, extending through the case 2 extends through and a rotor 11 wearing. To the rotor 11 around is a stator 12 inside the case 2 arranged attached to the inner wall in a suitable manner.

The armature shaft 10 extends through the front axial end in this example 6 of the housing 2 with a projecting output section. The rear end portion of the armature shaft 10 (in the 2 right) is over a rear bearing 16 in a rear end shield 9 (also referred to as B-end shield) in the housing 2 rotatably mounted. The rear end shield 9 is like the front end shield 7 with the housing 2 tightly connected.

Furthermore, at the rear end plate a switching unit 13 and a customer contact unit 14 (see also 4 ) appropriate. The switching unit 13 has a corresponding electrical control unit for the electric machine 1 on. The customer contact unit 14 has, for example, a custom electrical connection for the electrical machine 1 on, which is sealed here and in one of the housing 2 surrounded space between the rear axial end 5 and the rear end shield 9 located.

3 shows a sectional view of a second embodiment of the electric machine according to the invention 1 , In this second embodiment, the floor 3 at the front axial end 6 of the housing 2 with a central warehouse 4 for the front bearing 15 Mistake. The floor 3 forms here simultaneously and in one piece with the housing 2 a front bearing plate.

Finally shows 4 an exploded perspective view of the second embodiment according to 3 in partial section view.

It can be seen that the stator 3 Has windings, which at the switching unit 13 are connected. The rotor 11 is equipped in this example with permanent magnets, wherein the electric machine 1 can be a brushless motor.

The the present invention is not limited to the above concrete or limited abstract embodiments, but can be modified in any way without depart from the subject matter of the present invention.

For example, the case 2 form a heat sink as extruded part with a high pure aluminum content with resulting high thermal conductivity. The in the stator 12 heat generated by heat conduction well on the housing 2 be transmitted. Likewise, the housing 2 as a heat sink, for example, for power semiconductors, the switching unit 13 be used by appropriate heat transfer sections between heat sources and the inner wall of the housing 2 be provided.

So the invention is not limited to brushless motors. Of course, motors and / or Generators with collectors installed in such a housing become.

1

electrical machine

2

casing

3

ground

4

bearing seat

5

rear axial end

6

Front axial end

7

Front end shield

8th

Lagerflansch

9

rear end shield

10

armature shaft

11

rotor

12

stator

13

switching unit

14

Customer contact unit

15

Front camp

16

rear camp

17

Rear bearing seat

18

sealing element

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited non-patent literature

• - DIN 8583 [0012]

Claims (12)

Casing ( 2 ) an electric machine ( 1 ), which is produced by an extrusion molding process. Housing according to claim 1, characterized in that the housing ( 2 ) is produced by means of a forward, backward or combined extrusion process. Housing according to one of claims 1 or 2, characterized in that the housing ( 2 ) with a floor ( 3 ), which forms an axial stop. Housing according to one of claims 1 or 2, characterized in that the housing ( 2 ) with a floor ( 3 ) provided with a bearing receptacle ( 4 ) is provided and forms a bearing plate. Housing according to one of the preceding claims, characterized in that the housing ( 2 ) consists of an Al wrought alloy. Electric machine ( 1 ), with a housing ( 2 ) for inclusion in warehouses ( 15 . 16 ) rotatably mounted armature shaft ( 10 ) and a stator ( 12 ) wherein the housing ( 2 ) is produced by means of an extrusion process. Machine according to claim 6, characterized in that the housing ( 2 ) a floor ( 3 ), which has an axial stop for a bearing receptacle ( 4 ) bearing plate ( 7 ). Machine according to claim 6, characterized in that the housing ( 2 ) is formed as a housing according to at least one of claims 2, 4 or 5. Machine according to one of claims 6 to 8, characterized in that the housing ( 2 ) a heat sink for the electric machine ( 1 ). Machine according to one of claims 6 to 9, characterized in that the electric machine ( 1 ) is designed as a motor and / or as a generator. Machine according to claim 10, characterized in that the electric machine ( 1 ) as a sealed electrical machine ( 1 ) is trained. Machine according to one of claims 6 to 11, characterized in that the machine is part of a steering gear or a steering system of a motor vehicle.