WIPER MOTOR

Abstract

A wiper motor having a gearbox housing which comprises a pot-shaped main body for forming a receiving space for a gear mechanism is disclosed. An opening in the main body can be closed by a gearbox cover, and a plurality of latching connections, which act in the direction of a joining direction between the main body and the gearbox cover, are formed between the main body and the gearbox cover. Each comprise an elastically deformable first latching element and a second latching element which interacts with the first latching element in a form-fitting manner, and wherein centring means are provided on the gearbox housing for the play-free positioning of the gearbox cover relative to the main body in a rotational angle position, which extends perpendicularly to the joining direction, between the main body and the gearbox cover.

Description

TECHNICAL FIELD

The invention relates to a wiper motor which serves as a constituent part of a wiper device for cleaning a vehicle glass. In particular, the invention relates to a configuration of the wiper motor that, by contrast with the prior art, allows simpler construction and mounting of a gearbox cover on the gearbox housing of the wiper motor.

PRIOR ART

A wiper motor having the features of the preamble of claim 1 is known from practice. Such a wiper motor is distinguished by a gearbox housing which comprises a pot-shaped main body whose opening can be closed by a gearbox cover in order for the gear mechanism arranged in the gearbox housing to be protected from ingress of media or dirt.

In this context, it is already known that, to avoid screw connections or to reduce the number of components and to simplify the mounting process, a plurality of latching connections can be provided between the main body of the gearbox housing and the gearbox cover that are formed when axially joining the gearbox cover to the main body of the gearbox housing. It is essential here, moreover, that the gearbox cover is arranged in a certain rotational angle position with respect to a longitudinal axis of the gearbox housing that is customarily aligned with an output shaft of the gear mechanism arranged in the gearbox housing. This rotational angle position should in particular also allow a play-free arrangement of the gearbox cover on the gearbox housing with respect to a circumferential direction about said longitudinal axis. For this purpose, the known wiper motor comprises, in addition to the latching connections, centring means which consist of at least one centring pin on the gearbox cover that interacts with a mating centring opening in an extension on the gearbox housing. These centring means thus constitute, in addition to the latching connections, additional components or elements which necessitate additional installation space and material requirement on the main body and the gearbox cover of the gearbox housing.

DISCLOSURE OF THE INVENTION

The wiper motor according to the invention having the features of claim 1 has the advantage that the centring means do not require any additional installation space nor any additional material requirement on the gearbox housing and separate components to form the centring means. The idea on which the invention is based is to form the centring means as an integral constituent part of the latching connections, to be precise in combination with a particular arrangement of the latching connections on the gearbox housing.

Specifically, in order to achieve the aforementioned advantages, the teaching of the invention proposes that the wiper motor be configured in such a way that the centring means are formed by two latching connections, that the centring means of each of the two latching connections are formed by in each case a first bearing face on the first latching element and a second bearing face on the second latching element, that the first bearing faces and the second bearing faces, in the joined state between the main body of the gearbox housing and the housing cover, bear against one another as viewed in the circumferential direction about a longitudinal axis of the gearbox housing, and that the first bearing faces and the second bearing faces, as viewed with respect to a direction of rotation about the longitudinal axis, are in each case arranged on the same side of the first latching elements and of the second latching elements.

In particular, the last-mentioned feature of the geometric assignment of the bearing faces on the latching elements makes it possible to ensure that the gearbox cover is arranged relative to the main body of the gearbox housing so as to be rotational angle play-free with respect to a longitudinal axis of the gearbox housing.

Advantageous developments of the wiper motor according to the invention are set forth in the dependent claims.

To optimize the freedom of rotational angle play by the centring means, it is advantageous if the two latching connections serving to form the centring means are arranged at opposite regions, that is to say arranged with an offset from one another in particular by approximately 180°, with respect to the longitudinal axis of the gearbox housing that extends parallel to the joining direction between the gearbox cover and the main body of the gearbox housing.

To increase the stiffness or strength of the elastically deformable latching element and to achieve a deformation of the first latching element that occurs only in one direction during the joining operation, there is provision, moreover, that the first latching element comprises two webs which are connected to one another by a cross-web and which delimit a preferably rectangular cutout into which the second latching element projects in the joined state of the gearbox housing.

For the joining operation, it is, moreover, particularly advantageous in the last-mentioned configuration if the first bearing face is designed to be lengthened outside the cutout to form a guide face. As a result, guiding and centring of the latching elements of the centring means with respect to one another already takes place during the axial joining of the gearbox housing.

In order, during the mounting operation, to form the latching connections without the risk of damage to the latching elements and with a limited mounting force in the joining direction, it is, moreover, advantageous if the second latching element comprises a run-on slope against which the first latching element bears during the joining operation of the gearbox housing, with said latching element being elastically deformed. As a result, continuous (elastic) deformation of the first latching element occurs without force or stress peaks.

Further improved centring between the main body of the gearbox housing and the gearbox cover with respect to the longitudinal axis in the case of a guide face designed to be extended to outside the cutout is achieved if the guide face has a lateral bevel for interacting with the second bearing face on the second latching element.

In order to form a secure and reliable, sealed connection as viewed over the entire circumference between the (pot-shaped) main body of the gearbox housing and the gearbox cover, there is, moreover, preferably provision that at least one additional latching connection between the main body and the gearbox cover is provided, and that the at least one additional latching connection, in the joined state of the gearbox housing, has a rotational angle play with respect to a plane extending perpendicularly to the joining direction. Expressed in other words, this means that the at least one additional latching connection does not serve for the rotational angle play-free arrangement of the gearbox cover on the main body of the gearbox housing, but only for axially securing and bracing the gearbox cover. This also avoids a situation in which a geometrically overdetermined geometry between the main body and the gearbox cover is formed that otherwise could be compensated for only by highly accurate production of the latching elements on the main body of the gearbox housing and the gearbox cover.

Particularly in conjunction with the gearbox cover being formed from plastic, it is advantageous if the first latching element is arranged on the gearbox cover, and the second latching element is arranged on the main body.

A further preferred geometric configuration provides that the cutout has a first width on the first latching element that is greater than a second width of the second latching element, with the result that, in the joined state of the gearbox housing, a gap is formed between the cutout in the first latching element and the second latching element on the side facing away from the bearing faces.

Further advantages, features and details of the invention will emerge from the following description of preferred embodiments of the invention and also from the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a wiper motor in a bottom view,

FIG. 2 shows an operation of joining a gearbox cover to a gearbox housing of the wiper motor according to FIG. 1 in a perspective illustration,

FIG. 3 shows a subregion of the wiper motor according to FIG. 1 with a joined gearbox housing,

FIG. 4 shows a side view of a first latching connection for forming centring means between the gearbox cover and the gearbox housing, and

FIG. 5 shows a side view of a second latching connection between the gearbox cover and the gearbox housing, with the second latching connection serving for axially securing the gearbox cover.

EMBODIMENTS OF THE INVENTION

Identical elements or elements having an identical function are denoted by the same reference numbers in the figures.

In FIG. 1 there is shown a wiper motor 10 as a constituent part of a wiper device for cleaning a vehicle glass (not shown). Here, the wiper motor 10 acts indirectly, via a wiper linkage, or directly on a wiper arm on which in turn a wiper blade for cleaning the vehicle glass is arranged or fastened.

The wiper motor 10 comprises a gearbox housing 12 onto which an electric motor is flanged with its motor housing 14. The gearbox housing 12 consists of at least two parts, namely a preferably pot-shaped main body 16 as first part whose opening 18 can be closed by a gearbox cover 20 as second part. The gearbox housing 12 forms, in the joined state, a closed receiving space 22 for receiving a gear mechanism (not shown in detail) which acts on an output shaft 24 (FIG. 2) which is connected, at least indirectly, to the wiper arm or the wiper blade. The output shaft 24 simultaneously forms a longitudinal axis 26 on the gearbox housing 12, with a joining direction 28 extending parallel to or in alignment with the longitudinal axis 26 when mounting the gearbox cover 20 on the main body 16. The longitudinal axis 26 and the joining direction 28 extend perpendicularly to the drawing plane of FIG. 1.

Along the outer circumference of the gearbox housing 12 there are formed or arranged, according to the illustration of FIG. 1, two first latching connections 30, 31 and, by way of example, three second or further latching connections 32. Furthermore, the two first latching connections 30, 31, when viewing the longitudinal axis 26, are arranged at opposite rotational angle regions 33, 34, that is to say offset from one another by approximately 180°, on the gearbox housing 12.

The two first latching connections 30, 31 serve for the play-free positioning or arrangement of the gearbox cover 20 relative to the main body 16 in a circumferential direction extending concentrically around the longitudinal axis 26, that is to say to avoid a rotational angle play about the longitudinal axis 26. Furthermore, the two first latching connections 30, 31 also serve to fix the gearbox cover 20 on the main body 16 in the axial direction, that is to say in the direction of the longitudinal axis 26. By contrast, the three second latching connections 32 serve exclusively for axially securing the gearbox cover 20 on the main body 16, with the result that a rotational angle play with respect to the longitudinal axis 26 can occur at the second latching connections 32 should the first latching connections 30 not be present or formed.

The two first, preferably identically formed, latching connections 30, 31 each comprise a first latching element 36, 37 arranged on the gearbox cover 20. Here, the first latching element 36, 37 is integrally or monolithically formed on the gearbox cover 20, which consists of plastic and takes the form of an injection-moulded part. The first latching element 36, 37 is arranged on the gearbox cover so as to be elastically deformable in a direction extending perpendicularly to the longitudinal axis 26 and comprises two webs 38, 39 which, in the exemplary embodiment, each have a rectangular cross section and extend parallel to one another. On the side facing away from the gearbox cover 20, the two webs 38, 39 are connected to one another by means of a cross-web 41. The two webs 38, 39 along with the cross-web 41 delimit, together with the gearbox cover 20, a rectangular cutout 42 having an inner width B.

The one web 38 is designed to be lengthened outside the cutout 42 on the side facing away from the gearbox cover 20 and facing the cutout 42 to form a guide face 44. The guide face 44 transitions, moreover, into a bevel 46 arranged at an angle α. Here, the bevel 46 is situated on the side facing the web 39. Within the cutout 42, the web 38 of the first latching element 36, 37 forms a first bearing face 48 which extends parallel to and in alignment with the guide face 44.

According to the illustration of FIGS. 3 and 4, with the first latching connections 30, 31 formed, a second latching element 49, 50 of the first latching connection 30, 31 is received within the cutout 42. The second latching element 49, 50, which is integrally formed or realized on the main body 16, comprises an obliquely extending run-on slope 51. Furthermore, the second latching element 49, 50 has an outer width b which is less than the inner width B of the cutout 42. On the side facing the first bearing face 48, the second latching element 49, 50 has a second bearing face 52 interacting with the first bearing face 48.

The first latching elements 36, 37 form, together with the second latching elements 49, 50, centring means 55 for avoiding a rotational angle play about the longitudinal axis 26, with the centring means 55 in each case being formed by a first bearing face 48 on the first latching element 36, 37 and a second bearing face 52, interacting with the first bearing face 48, on the second latching element 49, 50.

Furthermore, it is essential that, with the gearbox housing 12 joined, that is to say with the first latching connections 30, 31 formed, the first bearing faces 48 and the second bearing faces 52 are arranged in bearing contact or in a play-free manner on the gearbox housing 12 on mutually facing sides of the first latching elements 36, 37 and of the second latching elements 49, 50, and that the first bearing faces 48 and the second bearing faces 52, when viewed with respect to a direction of rotation about the longitudinal axis 26 extending, for example, in the clockwise direction and indicated by the arrow 64 in FIG. 1, are in each case arranged on the same side of the first latching elements 36, 37 and of the second latching elements 49, 50. Furthermore, a gap 53 (FIG. 4) is formed, on the side facing away from the bearing faces 48, 52, between the first latching element 36, 37 and the second latching element 49, 50. The consequence of such an arrangement is that the gearbox cover 12 is arranged play-free with respect to a circumferential direction about the longitudinal axis 26 in a rotational angle play-free manner relative to the main body 16. The arrangement of the first bearing faces 48 relative to the second bearing faces 52 on the two first latching connections 30, 31 is illustrated in FIG. 1 by the planes 56, 57.

By contrast to the two first latching connections 30, 31, when forming the, by way of example, three second latching connections 32, which likewise comprise elastically deformable first latching elements 58 on the gearbox cover 20 and (rigid) second latching elements 60 on the main body 16 in a corresponding manner to the first latching connections 30, 31, there is formed between the respective latching elements 58 and 60, with the second latching connections 32 formed, and as viewed in the longitudinal direction, in each case a gap 61, 62 in the region of the cutouts 63 (FIG. 5), that is to say a rotational angle play about the longitudinal axis 26 is present.

During the operation of joining the gearbox cover 20 to the main body 16 of the gearbox housing 12, the latching connections 30, 31 and 32 are oriented relative to one another with respect to the longitudinal axis 26, that is to say brought into an aligned rotational angle position. Then, for example, the gearbox cover 20 is moved towards the main body 16 in the joining direction 28.

What occurs here first of all, where appropriate, is that the bevels 46 of the two first latching elements 31, 32, for centring between the gearbox cover 20 and the main body 16, come into contact with the bearing faces 52 of the second latching elements 49, 50. Then, the cross-web 41 comes into operative connection with the run-on slopes 51 of the second latching elements 49, 50, with the result that the first latching elements 36, 37 are elastically deformed in a direction extending perpendicularly to the longitudinal axis 26. Upon reaching the axial end position of the gearbox cover 20 with respect to the direction of the longitudinal axis 26, the latching connections 30, 31 and 32 are formed by the first latching elements 36, 37 and 58 passing into the cutouts 42 and 63 and thereby fixing the gearbox cover 20 on the main body 16.

The wiper motor 10 described so far may be altered or modified in a wide variety of ways without departing from the concept of the invention.

REFERENCE DESIGNATIONS

• • 10 Wiper motor
  • 12 Gearbox housing
  • 14 Motor housing
  • 16 Main body
  • 18 Opening
  • 20 Gearbox cover
  • 22 Receiving space
  • 24 Output shaft
  • 26 Longitudinal axis
  • 28 Joining direction
  • 30 First latching connection
  • 31 First latching connection
  • 32 Second latching connection
  • 33 Rotational angle region
  • 34 Rotational angle region
  • 36 First latching element
  • 37 First latching element
  • 38 Web
  • 39 Web
  • 41 Cross-web
  • 42 Cutout
  • 44 Guide face
  • 46 Bevel
  • 48 Bearing face
  • 49 Second latching element
  • 50 Second latching element
  • 51 Run-on slope
  • 52 Bearing face
  • 53 Gap
  • 55 Centring means
  • 56 Plane
  • 57 Plane
  • 58 Latching element
  • 60 Latching element
  • 61 Gap
  • 62 Gap
  • 63 Cutout
  • 64 Arrow
  • B Inner width
  • b Outer width
  • α Angle

Claims

1. A wiper motor, having a gearbox housing, comprising: a pot-shaped main body for forming a receiving space for a gear mechanism, wherein an opening in the main body is closed by a gearbox cover,wherein a plurality of latching connections, which act in the direction of a joining direction between the main body and the gearbox cover, are formed between the main body and the gearbox cover and each comprise an elastically deformable first latching element and a second latching element which interacts with the first latching element in a form-fitting manner,wherein centring means are provided on the gearbox housing for the rotational angle play-free positioning of the gearbox cover relative to the main body about a longitudinal axis of the gearbox housing,wherein the centring means are formed on two latching connections,wherein the centring means on each of the two latching connections are formed by in each case a first bearing face on the first latching element and a second bearing face on the second latching element,wherein the first bearing faces and the second bearing faces bear against one another in a play-free manner in the joined state between the main body and the gearbox cover, andwherein the first bearing faces and the second bearing faces, as viewed with respect to a direction of rotation about the longitudinal axis, are in each case arranged on the same side of the first latching elements and of the second latching elements.

2. The wiper motor according to claim 1, wherein the latching connections serving to form the centring means are arranged at opposite rotational angle regions) with respect to the longitudinal axis, which extends parallel to the joining direction, of the gearbox housing.

3. The wiper motor according to claim 1, wherein the first latching element comprises two webs which are connected to one another by a cross-web and which delimit a preferably rectangular cutout into which the second latching element projects in the joined state of the gearbox housing.

4. The wiper motor according to claim 3, wherein the first bearing face is configured to be lengthened outside the cutout to form a guide face.

5. The wiper motor according to claim 3, wherein the second latching element comprises a run-on slope against which the first latching element bears during the joining operation of the gearbox housing and is thereby elastically deformed.

6. The wiper motor according to claim 4, wherein the guide face comprises a lateral bevel for interacting with the second bearing face on the second latching element.

7. The wiper motor according to claim 1, wherein at least one additional latching connection between the main body and the gearbox cover is provided, and in that the at least one additional latching connection, in the joined state of the gearbox housing, has a rotational angle play with respect to a plane extending perpendicularly to the joining direction.

8. The wiper motor according to claim 1, wherein the first latching element is arranged on the gearbox cover, and the second latching element is arranged on the main body.

9. The wiper motor according to claim 1, wherein the gearbox cover consists of plastic.

10. The wiper motor according to claim 5, wherein the cutout has a first width which is greater than a second width of the second latching element within the cutout, with the result that, in the joined state of the gearbox housing, a gap is formed between the cutout and the second latching element on 20 the side facing away from the bearing faces.