WO2008095862A1

WO2008095862A1 - Dc motor

Info

Publication number: WO2008095862A1
Application number: PCT/EP2008/051211
Authority: WO
Inventors: Rüdiger BRIESEWITZ; Dieter Dinkel
Original assignee: Continental Teves Ag & Co. Ohg
Priority date: 2007-02-05
Filing date: 2008-01-31
Publication date: 2008-08-14
Also published as: JP5372777B2; JP2010518802A; DE102007049209B4; DE102007049209A1

Abstract

The invention relates to a DC motor, in particular an electric motor with a stator, containing a brush-holding plate made from plastic and a motor housing, comprising a cylindrical wall region for accommodating permanent magnets, with a rotor, containing a shaft with an end piece for a winding support and with a bearing arrangement between the stator and the rotor. The invention is based on the object of making simplified and less expensive production of electric motors of different power classes possible taking into consideration miniaturization criteria. The object is achieved by a uniformly standardized brush-holding plate being provided for the formation of a machine construction kit system containing machine product lines which are capable of electrically different powers, using predominantly the same machine component parts, and by the fact that each motor housing has a standardized interface for accommodating the standardized brush-holding plate.

Description

DC motor

The invention relates to a DC motor, in particular electric motor for driving pumps for slip-controlled brake systems, essentially comprising a fixed part, in particular stator, comprising a motor housing comprising a cylindrical wall portion for receiving permanent magnets, and having a rotating part, in particular rotor, containing a shaft with an end piece for a winding support, as well as with a bearing between stator and rotor, and with electrical connection components such as in particular carbon brushes in an electrical connection between the rotor and an electrical load or an electrical power supply.

Such electrical machines for motor vehicles are generally designed as a direct current machine and serve primarily the energy conversion in a motor vehicle, preferably for the conversion of electrical energy into hydraulic energy for the purpose of driving stability control or for driving hydraulic actuators.

For example, from DE 295 03 978 Ul a motor pump unit is apparent with an axial length shortened electric motor. A topffömig designed motor housing is located with its pot bottom side to the outside moisture protected against the pump housing, a rotor shaft end protrudes through a central opening of the pot bottom side and A-side is mounted on a fixed in the interference fit rotor shaft bearing directly centered in a bearing receptacle of the pump housing to this, and the rotor shaft end via the A-side plugged rotor shaft bearing in the direction of the B-side of the rotor shaft axially supported against the pot bottom side of the motor housing. Of the known electric motor allows a compacted construction in the axial direction.

In principle, the geometric design of an electric motor, in particular the design of length and diameter, as a motor design size. In particular, the variables have an influence on the dimensioning of the engine torque. Although the dimensioning and in particular the minimization of a magnetic air gap is a very effective measure to change engine characteristics. However, the variation of other constructive geometric properties is convincing due to its particular unpretentiousness and cost-effective, simple reproduction within a mass production. In order to provide the required services, for example, diameter-different motors are produced, each with individually manufactured brush holder plates. However, this approach has the disadvantage that always an inappropriately large number of different sized engine components must be made and stored. This unduly increases the required logistical effort.

The invention is therefore based on the object to enable a simplified and cost-effective production of electric motors of different power classes. A further object of the invention is to provide a DC motor of compacted construction which allows at least equal or increased power.

The object is solved by the characterizing features of claim 1. This solution consists in principle of uniformly standardized interfaces for standardized components - at least a standardized interface for a standardized brush holder plate or Shaft - provide so that can be tapped by installing this standard brush plate or shaft in the different powerful engine series rationalization potential. Advantageous developments with further details of the invention will become apparent from dependent claims in conjunction with the description and the drawings. In the drawing shows each in section as well as enlarged

1 shows an electrical machine according to a first design comprising standard magnets with enlarged details X and Y,

Fig. 2 shows an electrical machine according to a second design with reinforced magnets, and

3 shows an electrical machine according to a third design with extended motor housing.

The drawing illustrates a designed as an electric drive machine 1 which is designed in particular for use in conjunction with a motor pump unit. To drive the pump, the machine 1 is flanged to a not further clarified receiving body 2, which has not further clarified pump components, electromagnetically actuated valves, memory, damper and channels for the hydraulic connection of said components. In general, the rotational movement of a rotor 3 of the machine 1 is converted into a linearly oscillating movement of the pump piston by means of an eccentric 5 connected in a rotationally fixed manner to the shaft 4. The shaft 4 is standardized and has a thickened center piece 6 and two end pieces 7,8 which have a reduced diameter compared to the center piece 6. The end piece 7 is formed eccentrically and engages in a not clarified crankcase to pump piston drive. The eccentric geometry can be designed to vary depending on the performance. The end piece 8 merges with a generously bevelled or rounded transition 9 into the middle piece 6. The tail 8 carries a winding support 10 with windings and a so-called A-bearing, which is formed space neutral by the gradation of the shaft 4 as a ball bearing, and an inner ring 12 which is seated directly on the shaft 4, and an outer ring 13, which in a cupped everted portion 14 is received by a stepped pot-shaped motor housing 15.

The middle piece 6 also carries a commutator 16, which is connected to electrical windings, and is acted upon by carbon brushes 17, which are arranged movably guided on a separate brush holder plate 18. The brush holder plate 18 is also designed as a bearing plate for a so-called B-bearing 19. The B-bearing 19 is designed as a ball bearing, the inner ring 20 is seated on the middle piece 6 of the shaft 4. An outer ring 21 is at least partially received by the brush holder plate 18.

The standardized brush holder plate 18 is made substantially in one piece from plastic material and has an inner ring 22 and an outer ring 23, which are interconnected by an annular flat disc 24 so that the brush holder plate 18 forms a lid-like closure member, the motor interior 25 substantially complete separated from the flanged pump unit. The disk 25 is placed in the axial direction with the smallest possible air gap on the winding support 10. In principle, the same applies if carbon brushes 17 are to be additionally arranged between the winding carrier 10 and the disk 24. The two rings 22,23 are so to the disc 24th connected, that they protrude substantially with their entire length at right angles to the radial main extension direction of the disc 24 and axially in the direction of the pump unit. A peripheral outer surface 26 of the outer ring 23 is tapered or convex outwardly rounded in the manner of a chamfer, so that the part of the outer ring 23 which is deeply inserted into the stepped motor housing 15 has a smaller outer diameter than a less deeply inserted part of the outer ring 23. Between the motor housing 15 and outer ring 23 is thereby given a cutout 27. The cutout 27 makes it possible to lower the rotor 3 particularly quickly into the motor housing 15 during assembly because it has a favorable influence on the air displacement.

Furthermore, the outer ring 23 of the brush holder plate 18 has a, circumferentially stepped shoulder 28, pointing in the direction of the motor interior, which is suitable in the axial direction for seating on a step 29 of the motor housing 15. Due to the peripheral support between shoulder 28 and step 29 not only increased axial Dichtungsanpresskräfte allows, but at the same time allows an additional labyrinthine seal. In the direction of receiving body (the pump), the outer ring 23 is provided with a stepped, even radially outwardly open, recess 30 which receives a sealing element 31 such that this elastic, three-sided contact between the motor housing 15, (pump) receiving body 2 and brush holder plate 18 allows when the motor housing 15 is seated on the receiving body 2. Shoulder 28 and recess 30 are arranged in alignment with each other in the axial direction, so that the necessary contact forces are transferred substantially directly directly in the axial direction. Furthermore, the tolerances and dimensions between recess 30, shoulder 28, motor housing 15 and receiving body 2 are exactly tuned so that the necessary elastic contact pressure when joining machine 1 and receiving body 2 results. At the same time, the brush holder plate 18 is effectively provided with axially effective spring characteristics if any axial forces are built up by receiving the B bearing 19.

The commutator 16 is at least partially aligned with the inner ring 22 and outer ring 23. Axially next to the commutator 16 and in front of the B-bearing 19, a so-called bulkhead 32 is provided, which extends substantially to a thickened emergency bearing 33, which can be effective at the same time as a gap or labyrinth seal, to the outer periphery of the shaft 4.

Figures 1 and 2 illustrate the box-like design identical part strategy with component identity regarding shaft 4, bearings 11,19, motor housing 15, commutator 16 and brush holder plate 18. For motor variation, only dimensions or material of permanent magnets 34 and the diameter of the winding support 10 are varied. This can be done relatively easily, because the winding support is usually made of lamellar stamped sheet metal parts. To change the power values, it is particularly recommended to use so-called neodymium magnets with the thickness t2, which allow an increased magnetic excitation. For further power variation, it is also possible to change the diameter in the section for receiving the permanent magnets 34, but care should be taken that the interface for receiving the standardized brush holder plate 18 is maintained.

Fig. 3 illustrates a representative of a series with increased overall length I ₃ , said variant - with the exception of the overall length I ₃ - otherwise identical in terms of essential features, components and properties identical to the embodiments of FIG. Come here Standard magnets are used which have the thickness t3 = ti.

In summary, it is possible to combine a larger number of identical parts and a relatively small number of individual parts with each other in the sense of a modular system. The identical parts are designed essentially identically only in dependence on the mechanical main and connection dimensions for all variants of a motor family, and the individually individually combined parts allow the variation of the desired electric drive power class. With these measures, a particularly favorable division of labor between the components involved is made possible.

The invention also makes it possible to reduce the volume of a DC motor and to vary its performance in a simple manner. To change the electrical power of the DC motor is preferably a change in diameter of the rotor 3. The described tuning of the components, it is possible in the sense of a modular system that a brush holder plate 18 is dimensioned in principle as a standard component, and at the same time acts as a bearing plate. A standardized brush holder plate 18 can therefore be provided for differently powerful dimensioned DC motors. By circumferential Abstützmöglichkeiten a particularly stable support for the brush holder plate 18 is created.

By the shaft 4 - in contrast to known DC motors - designed for motor-pump units, stepped, miniaturized ball bearings are used in exchange for plain bearings on pump-facing winding head. This allows an optimized space utilization. In a further step, for example permanent magnets 34 with an increased remanence can be used (eg neodymium material) - corresponding to FIG. 2.

In general, the described design principle makes it possible to represent a wide variety of electric motor power classes without having to exert any significant influence on the basic mechanical design.

LIST OF REFERENCE NUMBERS

1 machine

2 receiving body

3 rotor

4 wave

5 eccentrics

6 center piece

7 tail

8 tail

9 transition

10 winding carriers

11 bearings

12 inner ring

13 outer ring

14 section

15 motor housing

16 commutator

17 carbon brush

18 brush holder plate

19 bearings

20 inner ring (bearing)

21 outer ring (bearing)

22 inner ring (brush holder plate;

23 outer ring (brush holder plate;

24 slice

25 engine interior

26 outer surface

27 Saving

28 shoulder

29 level

30 recess

31 sealing element

32 bulkhead

33 emergency camp permanent magnet

Overall length thickness

Claims

claims

1. DC motor (1), in particular electric motor, for driving a pump for a slip-controlled brake systems, substantially with a fixed part, in particular stator, comprising a brush holder plate (18) and a motor housing (15), comprising a cylindrical wall portion for receiving Permanent magnet (34), and having a rotating part, in particular rotor, comprising a shaft (4) with an end piece (7,8) for a winding support (10) or an eccentric (5), and with a bearing between stator and rotor, wherein the end piece (7,8) between two bearings (11,19) is arranged, and with electrical

Connecting components such as in particular carbon brushes (17) in an electrical connection between the rotor and an electrical load or an electrical power supply, characterized in that for the formation of a machine toolbox comprising electrically different powerful machine series using predominantly identical machine components, a uniformly standardized brush holder plate (18 ), and that each motor housing (15) has a standardized interface for receiving the standardized brush holder plate (18).

2. DC motor according to claim 1, characterized in that in each case the end piece (7,8) of the shaft (4) in comparison with an adjacent center piece (6) stepped in diameter is formed reduced, and that the motor housing (15) adjacent to the cylindrical Wall portion has a circumferential gradation, the cylindrical wall portion for the permanent magnet (34) of a cylindrical portion for receiving a brush holder plate (18) separates.

3. DC motor according to one or more of the preceding claims, characterized in that a uniformly standardized shaft (4) is provided for the different powerful machine series.

4. DC motor according to one or more of the preceding claims, characterized in that the cylindrical wall portion for the permanent magnets (34) has a smaller diameter than the cylindrical portion for receiving the brush holder plate (18).

5. DC motor according to one or more of the preceding claims, characterized in that the brush holder plate (18) has an outer ring (23), an inner ring (22) and one, the two rings (23,22) interconnecting, disc (24) ,

6. DC motor according to one or more of the preceding claims, characterized in that an outer surface (26) from the outer ring (23) profiled in such a way, in particular chamfered or convex, is formed that between the motor housing (15) and outer ring (23) has a cutout ( 27) is provided.

7. DC motor according to one or more of the preceding claims, characterized in that the outer ring (23) has a stepped shoulder (28) for axial contact with the motor housing (15) and a radially and axially open recess (30) for a sealing element (31). has, and that shoulder (28) and sealing element (31) are provided in alignment with each other in the axial direction.