Securing element for a bearing element

The invention relates to a securing element (1; 1a) for a bearing device (50) in a housing (20) of a drive device (10), wherein the plate-like securing element (1; 1a) has two side legs (34, 35) and a base leg (36) which connects the side legs (34, 35), wherein, between the base leg (36) and the side legs (34, 35), there is formed a cutout (38) for receiving a shaft (12) which is mounted rotatably in a bearing (15), wherein the two side legs (34, 35) are designed to interact, by means of a first face side (21), with the bearing (15) and, by means of a second face side (23), with a stop surface (33) in the housing (20).

PRIOR ART

The invention relates to a securing element for a bearing device in a housing of a drive device, to a bearing device, and to a windscreen wiper motor having a bearing device.

A securing element for a bearing device in a housing of a drive device having the features of the preamble of claim1is already known from practice. The substantially flat securing element, which is U-shaped in plan view, is in this case arranged in a receptacle of a housing of the drive device such that one face side of said securing element is arranged so as to be regionally in abutting contact with a bearing which serves for the rotatable mounting of a shaft, whereas the other face side of the securing element is regionally supported against an abutment surface of the receptacle. The known securing element serves for fixing the bearing in the receptacle and for compensating component tolerances or preventing axial play between the components. For this purpose, it is necessary for the securing element to be braced, or arranged with a clamping fit, between the abutment surface of the receptacle and the face side of the bearing. To ensure this, the known securing element has elevations which are formed by means of a stamping process and which are arranged in the region of the two side legs and on a face side. The elevations, which are of dome-shaped form, make it possible, as the securing element is slid into the receptacle, for the securing element to be received in the receptacle with the abovementioned clamping connection being formed. A disadvantage here is that the securing element can be received with clamping action in the receptacle only if the axial gap in the receptacle between the abutment surface and that face surface of the bearing which faces toward the securing element has relatively narrow tolerances. Furthermore, depending on component tolerances, relatively high installation forces are required for the insertion of the securing element in the axial direction.

DISCLOSURE OF THE INVENTION

The securing element according to the invention for a bearing device in a housing of a drive device having the features of claim1has the advantage that it permits a greater range of tolerances with regard to the dimensioning of the receptacle in the housing of the drive device, and, at the same time, the forces required for installing the securing element in the receptacle of the drive device are reduced. These advantages are achieved according to the invention in that the securing element is at least regionally bent in an axis running perpendicular to the two directions of the plane of the securing element, and has a bulge. As a result of the bending of the securing element in an axis or direction running perpendicular to the plane of the securing element, said securing element can be elastically deformed as it is inserted into the receptacle between the stop surface of the receptacle and that face surface of the bearing which faces toward the securing element, wherein the deformation forces required for this purpose or the installation forces are relatively low. Furthermore, as a result of the elastic deformation, a relatively large tolerance for the size of the receptacle for the securing element in the housing is made possible, because, in the case of an axial gap of decreasing size in the receptacle, the bulge of the securing element is reduced to an ever greater degree during the installation until, in the extreme case, said securing element no longer has a bulge in the installed state. The dimension for the size of the receptacle for the securing element is thus determined by the dimension by which the securing element is bulged in the non-installed state. Furthermore, the form of such a bulge on the securing element can be produced very easily in terms of production by means of a bending process, such that, by contrast to the prior art, it is for example the case that no stamping steps or no plastic deformation of the material of the securing element (elevations) is necessary.

Advantageous refinements of the securing element according to the invention for a bearing device in a housing of a drive device are specified in the subclaims. The invention encompasses all combinations of at least two of the features disclosed in the claims, in the description and/or in the figures.

Arrangement or embodiment of the bulge of the securing element in the region of the side legs is particularly preferred in which the at least one axis, perpendicularly to which the securing element is bent, is the direction of the longitudinal extent of the side legs. This is realized against the background that the side legs normally have a greater length in terms of their longitudinal extent than the base leg. Furthermore, in this way, points of abutting contact between the securing element and the bearing and the stop surfaces in the housing are made possible on opposite sides of the shaft.

It is however alternatively also conceivable for the at least one axis about which the securing element is of bulged form to run perpendicular to the direction of the longitudinal extent of the base leg.

A uniform deformation of the securing element during the insertion into the receptacle of the housing is achieved if the bulge is formed by a radius. Furthermore, by means of such a radius, linearly increasing installation forces during the insertion of the securing element into the receptacle of the bearing device are also achieved, which can thus be monitored and evaluated in a particularly effective manner in terms of process technology.

In order that the securing element can be in abutting contact over the greatest possible area in the region of the receptacle, in order to thus reduce the contact pressure and thus the material loading of the housing, which is composed in particular of aluminium, it is advantageous if the securing element has planar portions at peripheral elements outside the bulge.

Provision may furthermore be made whereby the securing element, in the direction of the axis in which said securing element does not have a bulge, has an installation and stiffening portion which projects at 90 degrees from the plane of the securing element. Said portion has the effect firstly that a deformation of the securing element takes place only in the bulged region, and that, secondly, the portion can be used particularly effectively for enabling the securing element to be gripped by means of a tool, for example an installation robot, and inserted into the receptacle of the housing.

Provision may additionally be made whereby, correspondingly to the prior art, the securing element, at a first face side and in the region of the two side legs, has in each case one elevation, formed preferably by means of a stamping process, for abutment against the bearing.

In order to limit the required installation forces, for reasons relating to functionality, provision is furthermore made for the element to be composed of spring steel and to have a thickness of between 0.8 mm and 1.2 mm, preferably of 1.0 mm.

The invention also encompasses a bearing device in a housing of a drive device, having a receptacle for a bearing for the rotatable mounting of a shaft and having a securing element designed according to the invention in the manner described above, wherein the receptacle forms a stop surface on a side of the securing element situated opposite the bearing, and wherein the receptacle has, between the bearing and the stop surface, an axial gap with a width which corresponds at most to the structural height of the securing element in the region of the bulge and at least to the thickness of the material of the securing element. Finally, the invention also encompasses a windscreen wiper motor having a bearing device of said type.

Further advantages, features and details of the invention will emerge from the following description of preferred exemplary embodiments and on the basis of the drawing.

Identical elements or elements of identical function are denoted in the figures by the same reference designations.

FIGS. 1 and 3illustrate individual constituent parts of a windscreen wiper motor100. The windscreen wiper motor100has a drive device10, which comprises inter alia an armature14with an armature lamination assembly11and armature windings (not illustrated). The armature lamination assembly11is fastened rotationally conjointly to a shaft12of the armature14, wherein the shaft12is mounted rotatably about an axis of rotation13. The mounting of the shaft12is performed by means of multiple bearing bodies or bearings15, which are a constituent part of a bearing device50, wherein one of the bearings15is illustrated in the form of a rolling bearing or ball bearing inFIG. 3.

The bearing15comprises an inner ring16, which is fastened rotationally conjointly to the outer circumference of the shaft12, for example by shrink-fitting. Furthermore, the bearing15comprises an outer ring17, which is received, with the formation of an interference fit, in a receptacle19of the bearing device50of a housing20, composed preferably of aluminium, of the windscreen wiper motor100. Bearing bodies22are arranged, at uniform angular intervals about the axis of rotation13, between the inner ring16and the outer ring17.

Correspondingly to the illustration ofFIG. 3, one face surface24of the bearing15bears axially against a step26of the receptacle19. Also visible inFIG. 3is a commutator device28of the drive device10, which commutator device is received in a pot-shaped or cup-shaped housing portion29.

To force the shaft12together with the armature lamination assembly11in the direction of the step26, that is to say in the direction of the arrow31inFIG. 3or of the axis of rotation13, in order to compensate component tolerances and axial play, and to simultaneously fix the bearing15in the receptacle19, use is made of a securing element1according to the invention of the bearing device50, which securing element is, in the receptacle19, correspondingly to the illustration ofFIG. 3, supported by means of its two face surfaces21,23axially between the inner ring16of the bearing15and a stop surface33, running perpendicular to the direction of the arrow31or to the plane of the drawing ofFIG. 3, of the receptacle19.

The plate-like securing element1which can be seen particularly clearly inFIGS. 1 and 2is composed of spring steel and preferably has a thickness d of between 0.8 mm and 1.2 mm, preferably of 1.0 mm. Said securing element is of U-shaped form in plan view with two side legs34,35and a base leg36which connects the two side legs34,35to one another. Formed between the side legs34,35is a cutout38which is designed to receive the shaft12with play.

Correspondingly to the illustration ofFIG. 1, the securing element1is introduced into the receptacle19of the housing20in the direction of the arrow39(perpendicular to the axis of rotation13), wherein said securing element elastically deforms. It is essential here that, correspondingly to the illustration ofFIG. 2, the securing element1is designed to be regionally bent in a direction running perpendicular to the two axes X, Y running in the plane of the securing element1(seeFIG. 1). In the illustration ofFIG. 2, the Y axis runs perpendicular to the plane of the drawing ofFIG. 2. In the exemplary embodiment illustrated inFIGS. 1 to 3, the securing element1is designed to be regionally bent in the extent direction or along the two side legs34,35, and has, in an approximately central region in relation to the axial extent of the two side legs34,35, a bulge40which is formed by a radius R. The bulge40is formed uniformly on both face sides of the securing element1, that is to say the material thickness of the securing element1is at least substantially equal in the region of the two side legs34,35. On both sides of the bulge40, the securing element1has portions41,42of planar form, which in the installed state of the securing element1in the receptacle19preferably bear flat against the abutment surface33of the receptacle19(FIG. 3). Furthermore, the securing element1, in the region of the base leg36, has an installation and stiffening portion45which is bent through 90 degrees and which serves for example for the handling of the securing element1during the insertion into the receptacle19.

During the insertion or sliding of the securing element1into the receptacle19between the face surface26, facing toward it, of the bearing15and the stop surface33, the securing element1is elastically deformed in the region, in particular, of the bulge40, such that the latter acts with an axial force on the shaft12in the direction of the step26or of the axis of rotation13. For this purpose, it is essential that the securing element1has a structural height h perpendicular to the plane of the securing element1which is at least somewhat greater than the width w of the receptacle19between the bearing15and the stop surface33. Furthermore, the width w of the receptacle19must be at least as large as the thickness d of the securing element1.

The securing element1aillustrated inFIG. 4differs from the securing element1in that, on the side facing toward the installation and stiffening portion45and in the region of the bulge40, an elevation48is additionally formed on each side leg34,35, which elevation is preferably formed by means of a stamping process. The elevation48serves for punctiform abutment against the inner ring16of the bearing15.

The securing element1, la thus described may be altered or modified in a variety of ways without departing from the concept of the invention.

LIST OF REFERENCE DESIGNATIONS