DE102009001948A1 - Bearing shield for steering motor of steering of motor vehicle, has inner ring for receiving bearing, and outer ring connected with inner ring by spring-elastic elements, where shield is made of flexibly ductile plastic material - Google Patents

Abstract

The shield (1) has an inner ring (2) for receiving a bearing, and an outer ring (4) integrally connected with the inner ring by spring-elastic elements (3). The inner ring comprises a recess for receiving a shaft of the bearing, where the shield is made of flexibly ductile plastic material such as acrylonitrile butadiene styrene (ABS), polylacetate (PLA), PVC, polyester (PES) or synthetic resin. The spring-elastic elements are formed as spokes (7) that comprise reinforcing ribs, and the outer ring comprises extensions. Independent claims are also included for the following: (1) an electromotor drive of a steering of a motor vehicle (2) a method for manufacturing a bearing shield.

Description

The The present invention relates to a bearing plate for a electromotive drive.

Even though Applicable to any motors and shaft units, the present invention and the problems underlying it with respect to an electric motor drive in a motor vehicle explained in more detail.

electromotive Drives, such as. B. DC motors or AC motors, typically have a bearing plate for receiving a bearing on. Under a bearing plate is understood in particular the rear and / or front covers of a housing of the electromotive drive, which protects the inside of the engine and in each case a bearing of the Motor shaft receives. These end shields can be made of plastic or metal.

Out Plastic-manufactured end shields can be by means of an injection molding process manufacture and also can easily in the motor housing to be ordered. Furthermore, is made of plastic bearing shields in contrast to metal shields usually no costly post-processing necessary because the necessary Dimensional tolerances for installation in the motor housing already considered in the injection molding process. Out Plastic bearing shields are mainly because of of cheaper and easier compared to metal processing plastic cheaper to produce.

Problematic in both metallic and plastic end shields an undesirable noise of the electric motor during of operation. This is due to the fact that the storage of a Wave mostly by an arrangement of a fixed bearing and a Lot warehouse is realized. The end shields usually take up the lot bearing. The lot camp has the task of a game between the shaft and provide the end shield to z. B. a conditional by a change in temperature To compensate for linear expansion of the shaft. However, it comes through this game in the camp during the operation inevitably to a noise. Especially with personal applications, such. B. in the passenger compartment a motor vehicle, this is the person in the vehicle as disturbing and unpleasant.

In the DE 69 23 462 U1 a bearing for a rotating shaft of motors for eliminating the noise of a metal bearing plate is described. The bearing plate is there yielding in the axial direction and rigidly fixed in the radial direction in the form of a support disk. Due to the axial compliance of the bearing plate recorded by the bearing plate bearing can be biased on the shaft, which reduces the noise.

adversely In this type of storage is that metal already at a slight elongation can plastically deform, which in the worst case to failure of the entire motor Drive leads. Further, for the production a metallic bearing plate is a complex manufacturing process required, as the fit between end shield and motor housing must be made very accurately. This requires bearing plates made of metal significantly more expensive than plastic.

The Object of the present invention is now a bearing plate for an electromotive drive available to provide, which in operation the lowest possible noise unfolded. Furthermore, the invention has the object, as possible provide cost-effective end shield, in which the number of parts uriniert and the assembly costs for the installation in a drive unit as possible reduced is.

At least One of these objects is inventively a bearing plate solved with the features of claim 1.

Accordingly provided a bearing plate of an electric motor drive, which an inner ring for receiving a bearing and one with the inner ring integrally connected by resilient elements outer ring for fitting in a housing, wherein the end shield at least partially made of an elastically deformable plastic material is formed.

The basic idea of this invention is to produce the bearing plate for an electric motor drive from an elastically deformable plastic and designed by resilient elements constructively so that the entire bearing plate is elastically deformable in a defined manner. The spring-elastic elements of the bearing plate serve to elastically spring the bearing plate in all directions. As a result, any vibrations that are generated, for example, by imbalances or load changes of the shaft can be absorbed by the elastically deformable spring elements and thus damped. Furthermore, such a bearing plate can be easily arranged in a housing, without an elaborate machining of the mating surfaces between the bearing plate and the motor would be necessary because the elastically deformable bearing plate can be clamped directly into the housing. The resilient elements generate such a large radial force, that the bearing plate presses with its outer ring firmly and thus very stable to the housing inner wall, and thus a highly accurate fit between the bearing plate and the housing is generated. Thus, the bearing plate is frictionally secured (in particular by frictional force) in the housing.

Preferably The spring-elastic elements have a non-linear stiffness on, so that the tension for deformation of the spring-elastic elements increases with progressive elastic deformation of the spring elastic Elements. This ensures that there is always enough Air gap between the rotor and the stator is present.

Further the plastic material has better elastic deformability on than, for example, a metallic material, since the extensibility of a Plastic up to the breaking of the material many times higher is than with metallic materials. Also, it can be with the Plastic bearing shields simpler and, above all, less expensive produce.

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

According to one preferred development, the inner ring has a recess for Take up the shaft of the bearing and the end shield is with respect to the shaft in the axial direction and / or in the radial direction elastic deformable. This makes it possible for the Rotor shaft provided bearing accordingly through the bearing plate pretension. This will add to the noise reduced the electric motor drive.

According to one Another preferred development are only the elastic Elements of the bearing plate formed deformable. The outer ring and the inner ring of the bearing plate are therefore no longer elastic, but stiff. This allows the bearing of the inner ring precisely be absorbed and the outer ring dimensionally stable in the Housing be attached.

In Another embodiment is the end shield is formed as an injection molded part and is in particular complete made of plastic material. As a result, the inventive Bearing shields particularly cost-effective in high quantities produce. An injection-molded construction is also special advantageous for very dimensionally accurate finished parts, there the dimensional and shape tolerances of an injection molded part very much exactly. Furthermore, injection molded parts do not require any or at least only a minor reworking.

To a further preferred embodiment the plastic material is a thermoplastic material, preferably Acrylonitrile butadiene styrene (ABS), polylactate (PLA) or polyvinyl chloride (PVC), or a thermosetting material, preferably polyester (PES) or synthetic resin. These materials are perfect for producing an elastically deformable end shield. It can the end shield for different applications also from different be formed of these plastics. Depending on the application of the end shield can a suitable plastic can be selected that the required has elastic deformability and to the operational boundary conditions, such as z. Temperature or mechanical or chemical environmental conditions, optimally adapted. However, the end shield is not on this Plastics limited. Any further material, which accordingly is elastically deformable, can for the production of the bearing plate also be used.

The End shield has according to another preferred Embodiment a variety of resilient elements on. The variety of spring-elastic elements is symmetrical here arranged on the inner ring and on the outer ring. That's it possible, the axial and / or radial elastic deformation optimally adapted to the operating conditions. At a high required axial and / or radial stiffness of the bearing plate can have a correspondingly high number of elastic elements be formed on the bearing plate.

This would be the axial and / or radial stiffness of the bearing plate increase. Due to the symmetrical arrangement of the elastic Elements on the inner ring and on the outer ring of the end shield It can also be guaranteed that by the shaft transmitted to the bearing plate vibrations and forces evenly from the inner ring to the outer ring of the end shield and thus distributed to the housing.

According to one Another preferred development, the elastic extend Elements radially from the inner ring to the outer ring. This can be assured that the elastic elements the radial forces for clamping in the housing can absorb optimally.

In Another preferred embodiment is the spring-elastic elements designed as spokes. Show these spokes typically, but not necessarily one essentially elongated geometry. Through this elongated Geometry, the bearing plate can be particularly light and with low Material costs are manufactured.

According to one Another preferred embodiment, the spokes Reinforcing ribs on. The reinforcing ribs serve the defined increase in the stiffness of the Spokes. For example, the reinforcing ribs be arranged centrally in the longitudinal direction of a spoke. By the defined stiffness of the spokes makes it possible optimally design the end shield for the most diverse loads.

Of the Outer ring has according to another preferred Embodiment extensions, which are formed that they are in specially designed recesses a stator of an electric motor drive can intervene. These extensions serve z. B. to that shield against a secure rotary axial rotation. This allows the end shield especially safe in the housing of an electric motor Drive are fixed. Furthermore, it is also possible this Extensions z. B. to be provided with a latch to the Bearing plate in addition against axial displacement, to secure.

In a further preferred embodiment, the Inner ring and / or the outer ring of the bearing plate Reinforcing ribs on. As a result, these parts of the end shield can be particularly dimensionally stable be formed, whereby the inner ring, the bearing of the inner ring particularly precise leads and the outer ring can be arranged particularly dimensionally stable in the housing.

Further becomes an electric motor according to the present invention Drive, in particular a steering motor for the steering a motor vehicle, provided with a housing, with a rotor shaft, with at least one bearing for supporting the Rotor shaft, with at least one inventive End shield, which between the housing and the rotor shaft is clamped and which serves the admission of the camp. Such a Electromotive drive can be produced particularly inexpensively become. Furthermore, such an electric motor drive due its low, optimized noise especially well suited to being in a person-oriented application, for example in the passenger compartment of a motor vehicle to be used. Of the electromotive drive can z. B. as a DC or AC motor be educated.

According to one preferred development of the electric motor drive is the received by the inner ring of the bearing plate bearings as rolling bearings or designed as a plain bearing. Rolling bearings are suitable especially good for drives with a high number of revolutions, whereby plain bearings are particularly inexpensive bearings. Further It is also possible, the inner ring of the bearing plate through to form a particularly slippery plastic itself as a sliding bearing.

Of Further will be according to the present invention a method for producing a bearing plate available provided with the steps of: providing an injection mold; Inserting a bearing into the injection mold; Immediate overmolding of the arranged in the injection mold bearing with an elastic deformable plastic for forming an inventive Bearing plate. Due to the arrangement of the bearing directly in the injection mold The bearing of the shaft of the electromotive drive can be extra be produced inexpensively. An installation of the warehouse in the bearing plate is omitted. Furthermore, such Procedures are particularly well automated. This lowers the manufacturing costs an electric motor drive in addition.

After all becomes a method according to the present invention for mounting an electric motor drive available provided with the steps: providing a housing for the electric motor drive with arranged therein Stator and rotor shaft; Providing an inventive Bearing plate; Arranging a warehouse in a specially for it provided recess of the bearing plate; Arranging the end shield on the rotor shaft; Preloading the end shield in radial and / or taken in the axial direction with respect to the bearing Rotor shaft; Clamping the end shield in the housing. In this method, it is not necessary, the end shield in an elaborate way exactly on the mating surface to arrange in the engine. Furthermore, it is not necessary additional To arrange elements in the end shield to the bearing of the end shield pretension. By this method of assembling an electromotive Drive can thus significantly shorten its assembly time which also leads to a significant cost reduction in the entire manufacturing process leads.

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 a bearing plate according to the invention in the relaxed state;

2 a perspective view of a bearing plate according to the invention in the relaxed state;

3 a sectional view of a bearing plate according to the invention in the prestressed state;

4 a perspective view of a bearing plate according to the invention in the prestressed state;

5 a sectional view of a bearing plate according to the invention a preferred embodiment;

6 a perspective view of a bearing plate according to the invention 5 ; and

7 a sectional view of an electric motor drive according to the invention.

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

In the 1 is an inventive end shield 1 in the relaxed state shown in a sectional view. The bearing plate 1 has an inner ring 2 in which a bearing for supporting a shaft can be accommodated. For a secure axial arrangement of the bearing, the inner ring 2 an inner ring heel 20 on. Through this inner ring heel 20 it is no longer possible for a bearing received in it, in the axial direction 5 with respect to the inner ring 2 to shift. This inner ring heel 20 is arranged in the present illustration only on the left side. However, it is also possible, this inner ring paragraph 20 on both sides of the inner ring 2 to arrange.

Furthermore, the bearing plate 1 an outer ring 4 on which serves to be received in a housing of an electric motor drive. The inner ring 2 and the outer ring 4 are about elastic elements 3 connected with each other. The elastic elements 3 point in the area on the inner ring 2 a larger cross section than in the areas close to the outer ring 4 , This benefits the load distribution in the elastic plastic material, since in the area around the inner ring 2 a higher bending moment on the elastic elements 3 acts. Due to the elastically deformable plastic material from which this bearing plate 1 is made in one piece, it is possible that the end shield 1 in the axial direction 5 and in the radial direction 6 is elastically deformable.

In the 2 is the bearing plate according to the invention 1 in the relaxed state shown in a perspective and sectional view. The bearing plate 1 is in this representation - as in 1 - shown cut in the middle. It can be seen that the elastic elements 3 on the inner ring 2 and on the outer ring 4 are arranged symmetrically and radially from the inner ring 2 to the outer ring 4 extend. In this embodiment, a total of six elastic elements 3 that are not all visible on the end shield 1 intended.

In the 3 , is the bearing shield 1 in the prestressed, assembled state shown in a sectional view. It can be seen that the bearing shield 1 in the axial direction 5 and in the radial direction 6 has tense. The bearing plate 1 has a smaller radial diameter D2 in its preloaded state than in its relaxed state.

Due to this radial bias, it is the bearing plate 1 possible to be arranged without further connecting elements in a housing of an electromotive drive, since the elastic tension under which the bearing plate 1 is, here sufficient to jam in a housing and to arrange by means of friction immovably in this.

It is also possible here the outer ring 4 of the end shield 1 with an in 3 not shown to provide fold to the ply shield 1 additionally secure in a specially provided groove of the housing form fit.

Furthermore, one recognizes in the 3 that the bearing plate 1 is axially biased. The outer ring 4 is in the axial direction by a distance D3 against the inner ring 2 postponed. This shift causes an axial tension of the end shield 1 built, which serves, one in the end shield 1 provided bearing in the axial direction with respect to the shaft (in 7 related to the wave 14 to the right), because the spring force only on the outer ring 4 acts.

4 represents a bearing plate 1 in the prestressed state in a perspective view. It can be seen that the inner ring 2 to the outer ring 4 is axially displaced. This axial displacement causes an inner ring 2 provided bearing by the resilient elements 3 a tension is exercised. The elastic elements 3 further have reinforcing ribs 8th on. These reinforcing ribs 8th are in the middle of the elastic elements 3 arranged. Through these reinforcing ribs 8th can the axial and radial elastic stiffness of the elastic elements 3 be set. Forming the reinforcing ribs 8th Larger or smaller sized, so does the stiffness of the elastic elements 3 increases or decreases.

5 represents a bearing plate 1 a preferred embodiment in a sectional view. The this bearing plate 1 has an inner ring 2 for receiving a bearing and an outer ring 4 for fitting in a housing. Here is the end shield 1 , as can be seen from the uniform hatching integrally formed and has a homogeneous plastic material. Furthermore, in this embodiment, on the inner ring 2 reinforcing ribs 10 educated. These reinforcing ribs 10 increase the stiffness of the inner ring 2 for receiving the camp. Through these reinforcing ribs 10 can the inner ring 2 be formed dimensionally stable.

Further, on the outer ring 4 of the end shield 1 reinforcing ribs 11 educated. These reinforcing ribs 11 increase the stiffness of the outer ring on the one hand 4 , On the other hand, these reinforcing ribs increase 11 the bearing surface between the outer ring 4 of the end shield 1 and the housing. This creates the connection between housing and end shield 1 improved.

Further, on the outer ring 4 of the end shield 1 projections 9 designed to engage in specially provided recess of the stator. These extensions 9 can also be formed with a latch to latch into the recesses of the stator. Through these extensions 9 on the outer ring 4 of the end shield 1 becomes the end shield 1 secured against axial rotation with respect to the stator. This results in an even more stable arrangement of the bearing plate 1 in the housing and on the stator.

Corresponding 6 are more reinforcing ribs 11 as extensions 9 intended. In particular, in the embodiment shown in FIG 6 twice as many reinforcing ribs 11 like extensions 9 shown. The extensions 9 Aligned directly into the reinforcing ribs 11 in the opposite area of the outer ring 4 are provided. This is particularly advantageous in terms of manufacturing technology and, above all, as stability reasons, although a corresponding aligned arrangement of the extensions 9 opposite some of the reinforcing ribs 11 not necessarily required.

Furthermore, in 5 elastic elements 3 of the end shield 1 intended. These bend at a 90 ° angle from the inner ring 2 of the end shield to the outer ring 4 of the bearing plate and have a significantly smaller cross-section than the inner ring 2 and the outer ring 4 , As a result, we effectively realize a set bending range. However, this cross section may vary depending on the desired stiffness of the resilient elements 3 be formed larger.

6 shows the bearing plate 1 out 5 in a perspective view. The bearing plate 1 is here with twelve springy elements 3 educated. On the inner ring 2 of the end shield 1 are six reinforcing ribs 10 arranged, showing the rigidity of the inner ring 2 should increase. Further, on the outer ring 4 six extensions 9 intended to engage in the recesses of the stator. These extensions 9 are symmetrical on the outer ring 4 of the end shield 1 arranged.

7 provides an electric motor drive 19 with a bearing plate 1 in a sectional view. The electric motor drive 19 here has a cylindrically shaped housing 13 on. In the case 13 is a stator 15 firmly connected to the housing inner wall. Furthermore, the electric motor drive 19 a wave 14 on top of which a rotor 16 is attached. The wave 14 will be on the side A of the case 13 , which the drive side of the electric motor drive 19 represented by means of a fixed bearing 17 stored. The housing 13 has a bearing bush for this purpose 22 on, in which the fixed camp 17 is fixed. In the inner ring of the fixed camp 17 is the wave 14 axially fixed, so arranged not displaceable. On side B of the electromotive drive 19 is the wave 14 about one in a bearing plate 1 arranged floating bearing 18 stored.

The bearing plate 1 is here by non-positive torsion on the housing 13 arranged. For this purpose is on the inside of the case 13 in the area between the mounted end shield 1 and on the case 13 attached stator 15 a paragraph 21 intended. At this paragraph are the elastic elements 3 on the outer ring of the end shield 1 arranged in the assembled state and thus form the required friction / frictional connection in the assembled state. Furthermore, the end shield 1 biased in the radial and axial directions with respect to the shaft. The radial preload of the end shield 1 causes the end shield 1 in a press fit in the housing 13 located.

Even though the present invention with reference to preferred embodiments fully described, it is not limited to but modifiable in a variety of ways.

The Inventive bearing plate, for example also made of glass fiber reinforced plastic (GRP) be. Furthermore, other composites for the End shield in question. Likewise, other plastic materials, such as As elastomeric plastics or other thermoplastic or thermosetting plastics, conceivable.

Furthermore, this end shield is not limited to electric motor drives, even if this application is particularly advantageous. Each size is conceivable and ranges from miniaturi From just a few watts of power to high-performance drives with a few kilowatts of power. The bearing plate according to the invention can also be used in gear units.

Further the spring-elastic elements can have different designs accept. Also, the number of spring elements can be as needed and, where appropriate, by other materials, such as As a metal reinforced.

1

end shield

2

inner ring

3

springy elements

4

outer ring

5

axial direction

6

radial direction

7

spoke

8th

reinforcing ribs

9

projections

10

reinforcing ribs of the inner ring

11

reinforcing ribs of the outer ring

12

camp

13

casing

14

wave

15

stator

16

rotor

17

fixed bearing

18

movable bearing

19

electromotive drive

20

Inner-paragraph

21

paragraph on the housing

22

bearing bush

A

page the electric motor drive

B

page the electric motor drive

D1

radial Diameter in relaxed state

D2

radial Diameter in the prestressed state

D3

distance between outer ring and inner ring

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 patent literature

• - DE 6923462 U1 [0006]

Claims (15)

End shield ( 1 ) for an electric motor drive ( 19 ), which has an inner ring ( 2 ) for receiving a bearing and one with the inner ring ( 2 ) in one piece by resilient elements ( 3 ) connected outer ring ( 4 ) for fitting in a housing ( 13 ), wherein the end shield ( 1 ) is at least partially formed of an elastically deformable plastic material. Bearing shield according to claim 1, characterized in that the inner ring ( 2 ) a recess for receiving the shaft ( 14 ) of the bearing and that the bearing plate ( 1 ) with respect to the shaft ( 14 ) in the axial direction ( 5 ) and / or in the radial direction ( 6 ) is elastically deformable. Bearing shield according to one of the preceding claims, characterized in that only the resilient elements ( 3 ) of the end shield ( 1 ) are formed deformable. Bearing shield according to one of the preceding claims, characterized in that the bearing plate ( 1 ) is formed as an injection molded part and in particular is formed entirely of plastic material. Bearing shield according to one of the preceding claims, characterized in that the plastic material is a thermoplastic Material, preferably acrylonitrile-butadiene-styrene (ABS), polylactate (PLA) or polyvinyl chloride (PVC), or a thermosetting material, preferably polyester (PES) or synthetic resin. Bearing shield according to one of the preceding claims, characterized in that the bearing plate ( 1 ) a plurality of resilient elements ( 3 ) and that the plurality of resilient elements ( 3 ) symmetrically on the inner ring ( 2 ) and on the outer ring ( 4 ) is arranged. Bearing shield according to one of the preceding claims, characterized in that the resilient elements ( 3 ) radially from the inner ring ( 2 ) to the outer ring ( 4 ). Bearing shield according to one of the preceding claims, characterized in that the resilient elements ( 3 ) as spokes ( 7 ) are formed. End shield according to claim 8, characterized in that the spokes ( 7 ) Reinforcing ribs ( 8th ) exhibit. Bearing shield according to one of the preceding claims, characterized in that the outer ring ( 4 ) Extensions ( 9 ), which are formed such that they in specially provided recesses of a stator ( 15 ) and / or on the inside of the housing ( 13 ) of an electromotive drive ( 19 ) can intervene. Bearing shield according to one of the preceding claims, characterized in that the inner ring ( 2 ) and / or the outer ring ( 4 ) of the end shield ( 1 ) Reinforcing ribs ( 10 . 11 ) exhibit. Electromotive drive, in particular steering motor for the steering of a motor vehicle, - with a housing ( 13 ), - with a rotor shaft, - with at least one bearing ( 18 ) for supporting the rotor shaft ( 14 ), - with at least one end shield ( 1 ) according to at least one of claims 1 to 11, which between the housing ( 13 ) and the rotor shaft ( 14 ) and which of the reception of the warehouse ( 18 ) serves. Electromotive drive according to claim 12, characterized in that the of the inner ring ( 2 ) of the bearing shield ( 1 ) received bearings ( 18 ) is designed as a rolling bearing or as a sliding bearing. Method for producing a bearing plate, comprising the steps of: - providing an injection mold; - inserting a warehouse ( 18 ) in the injection mold; Immediate overmolding of the bearing arranged in the injection mold ( 18 ) with an elastically deformable plastic to form a bearing plate ( 1 ) according to one of claims 1 to 11. Method for assembling an electromotive drive, comprising the steps of: - providing a housing ( 13 ) for the electromotive drive ( 19 ) with a stator ( 15 ) and rotor shaft ( 14 ); - Provision of a bearing plate ( 1 ) according to at least one of claims 1 to 11; - Arranging a warehouse ( 18 ) in a specially provided recess of the bearing plate ( 1 ); - arranging the end shield ( 1 ) on the rotor shaft ( 14 ); - preloading the end shield ( 1 ) in radial ( 6 ) and / or in axial ( 5 ) Direction relative to that of the bearing ( 18 ) recorded rotor shaft ( 14 ); - Clamping the end shield ( 1 ) in the housing ( 13 ).