Wiper motor for a vehicle

Abstract

The invention relates to a wiper motor (10) for a vehicle, comprising a housing (12) having a transmission housing (14) and a motor housing (18), wherein the motor housing (18) and the transmission housing (14) are connected to one another, wherein the motor housing (18) serves to accommodate an electronically commutated electric motor (20) which projects with a drive shaft (28) into the transmission housing (14), wherein the drive shaft (28) is mounted in the transmission housing (14) by means of a first bearing device (31) and in the motor housing (18) by means of a second bearing device (32), wherein the electric motor (20) has a rotor (26) which is arranged so as to be rotatable about a longitudinal axis (24), connected to the drive shaft (28) and surrounded by an annular stator (22).

Description

Wiper motor for a vehicle

[0001] The invention relates to a wiper motor for a vehicle, featuring particularly precise positioning between the motor housing and the transmission housing. As a result, both the mechanical functionality with regard to the orientation of a connecting element for electrically contacting a stator, and precise orientation of bearing devices of the rotor, and the electrical functionality for commutation in the electric motor are optimized.Prior art

[0002] A wiper motor for a vehicle using an electronically commutated electric motor is known from US 10,116,186 B2. In the case of the known wiper motor, the stator of the electric motor is arranged of the electric motor requires the angle position of the state motor housing, wherein the motor housing can be flange-mounted onto a multi-part housing by means of fastening screws. The housing accommodates, inter alia, a transmission which cooperates with a drive shaft of a rotor of the electric motor. Details regarding the precise positioning of the motor housing with respect to (the rest of) the housing cannot be gathered from the cited document.Disclosure of the invention

[0003] The wiper motor according to the invention for a vehicle having the features of Claim 1 has the advantage that its stator, which is accommodated in the motor housing, can be positioned highly precisely with respect to the transmission housing. This is essential insofar as the correct energization of the individual electrical phases of the electric motor requires very precise knowledge of the rotation angle position of the stator. In addition, precise orientation of the stator with a connecting element which is fastened thereto and projects into the transmission housing also allows the electrical contacting in a particularly simple and reliable manner by way of connection wires arranged in a transmission cover. In addition, it is also essential that the two bearing devices in the motor housing and in the transmission housing, said bearing devices serving to mount the rotor, are oriented aligned with one another with the greatest possible precision in relation to the longitudinal axis of the rotor in order to minimize friction losses and bearing wear.

[0004] Against the background of the above explanations, a wiper motor according to the invention for a vehicle having the features of Claim 1 therefore has a housing consisting of a transmission housing and a motor housing. The motor housing is connected to the transmission housing, wherein the motor housing serves to accommodate an electronically commutated electric motor which projects with a drive shaft into the transmission housing. The drive shaft is mounted in the transmission housing by means of a first bearing device and in the motor housing by means of a second bearing device. The electric motor has a rotor which is arranged so as to be rotatable about a longitudinal axis, connected to the drive shaft and surrounded by an annular stator. The stator is arranged in a defined first rotation angle position in relation to the longitudinal axis in the motor housing, wherein the connection between the motor housing and the transmission housing is effected by a plurality of fastening screws. The transmission housing and the motor housing are oriented with respect to one another in a second rotation angle position in relation to the longitudinal axis by positioning means, wherein the positioning means comprises extensions which are arranged on the transmission housing or / and on the motor housing and engage in opposing openings on the motor housing and / or on the transmission housing.

[0005] Advantageous developments of the wiper motor according to the invention for a vehicle are specified in the dependent claims.

[0006] In a preferred geometric arrangement of the positioning means and of the fastening screws, which minimize the required demand for space and material on the wiper motor, provision is made for the fastening screws and the extensions and openings to be arranged concentrically with respect one another.

[0007] In a structurally preferred development of the latter proposal, provision is made for the extensions to be designed in the shape of a sleeve with a through-bore through which the fastening screws project. In this case, provision is in particular made for a radial gap to be formed between the through-bore and the fastening screw. This makes it possible to enable the functions of the orientation between the motor housing and the transmission housing exclusively by the extensions and openings, whereas the axial bracing or the fastening of the motor housing to the transmission housing is effected by the fastening screws.

[0008] A further preferred structural refinement in the context of the latter proposal provides for the sleeve-shaped extension to be formed on a fastening flange and the opening to be formed on a mating flange, wherein cooperating stop surfaces are formed on the fastening flange and on the mating flange, said stop surfaces serving to form an axial stop between the motor housing and the transmission housing in the direction of the longitudinal axis. In other words, this means that the two stop surfaces on the transmission housing and the motor housing determine the axial end position of the motor housing with respect to the transmission housing.

[0009] In order to allow the smallest possible number of fastening screws while simultaneously having secure fastening of the motor housing to the transmission housing, provision is preferably made for two fastening screws to be present, which are arranged offset relative to one another at least approximately by 180° in relation to the longitudinal axis.

[0010] Furthermore, it is essential that moisture and foreign matter is prevented from passing via the connecting region between the transmission housing and the motor housing into the housing of the wiper motor. For this purpose, provision is preferably made for the transmission housing or the motor housing to have a seal web which runs radially around the longitudinal axis and engages in a seal groove which runs radially around the longitudinal axis, wherein a gap between the seal web and the seal groove is filled by a sealing element.

[0011] For geometric tolerance compensation or in order to allow particularly secure sealing, the sealing element is in the form of a seal medium which is liquid or paste-like in the processing state in order to optimally fill the gap.

[0012] Furthermore, provision is preferably made for the seal web and the seal groove to be arranged radially within the fastening screws and the positioning means.

[0013] With regard to the lowest possible weight, economically advantageous manufacture and the required precision of the housing components, provision is additionally made for the motor housing and the transmission housing to be in the form of aluminium die cast parts, and for the openings and extensions to be mechanically processed in order to form a push fit.

[0014] In order to highly precisely position the stator within the motor housing in the desired, required first rotation angle position, provision is made, in order to obtain the first rotation angle position, for an extension to be integrally formed on the motor housing, said extension form-fittingly cooperating with an opening formed on the stator.

[0015] In order to make it possible for such a wiper motor to be able to be arranged or installed both on the right-hand vehicle side and on the left-hand vehicle side as seen in the direction of travel of the vehicle, which usually necessitates differently designed transmission housings, provision is additionally made in a development of the latter proposal for a plurality of openings to be provided on the stator in order to be able to position the stator in the motor housing in at least two different first rotation angle positions.

[0016] Lastly, provision is made for the stator to be able to be electrically contacted by way of a connecting element which is arranged on the stator, projects into the transmission housing and there is contacted with connection lines which are arranged in a transmission cover and lead into a connection plug, wherein the transmission cover closes the transmission housing.

[0017] Further advantages, features and details of the invention will emerge from the following description of preferred embodiments of the invention and with reference to the drawings.Brief description of the drawings

[0018] shows an exploded illustration of a wiper motor,

[0019] shows a perspective illustration of a stator and a motor housing,

[0020] shows a perspective view of a motor housing and a transmission housing,

[0021] shows a section through the wiper motor according toin the connecting region between the motor housing and the transmission housing, and

[0022] shows an enlarged illustration of a detail ofEmbodiments of the invention

[0023] Identical elements or elements of identical function are provided with the same reference numerals in the figures.

[0024] illustrates the essential parts of a wiper motor 10, as it is used for cleaning a window of a vehicle. In this case, the wiper motor 10 may be arranged or positioned either on the right-hand vehicle side or on the left-hand vehicle side with regard to the direction of travel of the vehicle. The wiper motor 10 typically uses a wiper linkage (not illustrated) to drive two wiper blades which are connected to the wiper motor 10 by way of the wiper linkage.

[0025] The wiper motor 10 has a multi-part housing 12. The housing 12 comprises a transmission housing 14 which is in the form of an aluminium die cast part and the upper opening of which can be closed by a transmission cover 16 which consists of plastic and is in the form of an injection-moulded part. A motor housing 18 in the form of an aluminium die cast part is laterally flange-mounted on or fastened to the transmission housing 14. The motor housing 18 serves to accommodate an electronically commutated electric motor 20. The electric motor 20, formed in an internal rotor design, has an annular stator 22 which surrounds a rotor 26 which is rotatably mounted in a longitudinal axis 24. The rotor 26 has a drive shaft 28 with a toothing region 29. The drive shaft 28 projects with its toothing region 29 via an opening 30 into the transmission housing 14.

[0026] The rotor 26 is mounted in the housing 12 by means of two bearing devices 31, 32 (Figures 1 and 4). The first bearing device 31 is arranged in the transmission housing 14 in a first bearing receptacle 34. By contrast, the second bearing device 32 is arranged in the motor housing 18 in a second bearing receptacle 35 in accordance with the illustration inThe two bearing receptacles 34, 35 and bearing devices 31, 32 are oriented concentrically or aligned with respect to the longitudinal axis 24.

[0027] Rotatably mounted within the transmission housing 14 is a transmission wheel 36 which has, on its outer circumference, a toothing 37 which meshes with the toothing region 29 of the drive shaft 28. The transmission wheel 36 is connected to an output shaft 38 which projects via an opening on the transmission housing 14 out of the housing 12 and cooperates with the mentioned wiper linkage.

[0028] On the side of the motor housing 18 facing towards the transmission housing 14, a connecting element 40 projects from the stator 22 and serves to electrically contact stator wires 42 of the stator 22. The connecting element 40 also projects via the opening 30 into the transmission housing 14. There, the connecting element 40 is electrically contacted by way of connection lines in the form of leadframe elements which are not visible in the figures. The mentioned leadframe elements are arranged in the transmission cover 16 and regionally encapsulated by the plastic of the transmission cover 16. They lead into a connection plug 44 of the transmission cover 16, and there can be electrically contacted by way of a wiring harness mating plug. The transmission cover 16 can be connected to the transmission housing 14 by way of latching tongues 46.

[0029] The fastening of the motor housing 18 to the transmission housing 14 is effected by means of two fastening screws 48 which are arranged offset relative to one another at least approximately by 180° in relation to the longitudinal axis 24 or opposite one another. The region for fastening the motor housing 18 to the transmission housing 14 comprises, on opposite sides of the motor housing 18, fastening flanges 50 which projected from said motor housing perpendicularly to the longitudinal axis 24 and two mating flanges 52 which are arranged aligned with the fastening flanges 50 and laterally project on the transmission housing 14.

[0030] In accordance with the illustration in Figures 3 and 5, the two mating flanges 52 each have a blind bore 54 which runs parallel to the longitudinal axis 24 and has a threaded portion 55 in order to accommodate the fastening screws 48. The blind bore 54 is in the form of a stepped bore and has, on the side facing away from the threaded portion 55, an enlarged-diameter opening in the form of a centring region 56 as a constituent part of positioning means 58 between the transmission housing 14 and the motor housing 18. A sleeve-shaped extension 59 of the fastening flange 50 projects into the centring region 56. A push fit is formed between the outer diameter of the extension 59 and the inner diameter of the centring region 56. This is made possible by mechanical processing of the centring regions 56 and of the extensions 59.

[0031] Furthermore, it can be seen with reference tothat the fastening flange 50 has, on the side facing towards the mating flange 52, a first stop surface 61 which runs perpendicularly to the longitudinal axis 24 and cooperates with a second stop surface 62 on the mating flange 52 in order to limit the penetration depth of the centring region 56 into the blind bore 54 and to define the axial end position between the transmission housing 14 and the motor housing 18 in the direction of the longitudinal axis 24. A clearance 64 is additionally formed between a base 63 of the blind bore 54 and the fastening flange 50.

[0032] In order to accommodate the respective fastening screws 48, the fastening flange 50 has a through-bore 66, the inner diameter D of which is greater than the outer diameter d of the fastening screw 48, with the result that a radial gap 68 is formed within the fastening flange 50 between the through-bore 66 and the fastening screw 48.

[0033] The above-described arrangement and design of the positioning means 58 with the centring regions 56 and the extensions 59 allows precise orientation of the motor housing 18 in relation to the transmission housing 14 with regard to the rotation angle position in relation to the longitudinal axis 24 and the radially aligned orientation of the motor housing 18 and the transmission housing 14. Furthermore, the concentric arrangement of the positioning means 58 with respect to the fastening screws 48 and the threaded portions 55 minimizes the demand for space and material and the weight of the fastening flanges 50 and the mating flanges 52.

[0034] Furthermore, the transmission housing 14 has a seal web 70 which runs radially around the longitudinal axis 24, is arranged radially within a pitch circle diameter of the fastening screws 48 and engages in a seal groove 72, which runs radially around the longitudinal axis 24, on the motor housing 18. Formed between the seal web 70 and the seal groove 72 is a cross-sectionally U-shaped gap 74 for accommodating a sealing element 75. The sealing element 75 is preferably in the form of a seal medium 76 which is liquid or paste-like in the processing state.

[0035] In order to be able to position the stator 22 within the motor housing 18 in different, defined first rotation angle positions in relation to the longitudinal axis 24, the stator 22 has, as is best visible with reference to, a plurality of cutouts 79 formed in the region of a lower insulation 78 of the stator 22. The cutouts 79 cooperate with an extension 80 formed on the base of the motor housing 18 (). It is thus possible, by way of the cutouts 79 and the extension 80, for the stator 22 and the connecting element 40 to be positioned highly precisely with respect to the motor housing 18. This is inter alia necessary in order to form the electrical connection between the transmission cover 16 and the connecting element 40 when assembling the wiper motor 10. In addition, a second defined rotation angle position of the motor housing 18 with respect to the transmission housing 14 is realized by the fastening flanges 50 and the mating flange 52 by means of the positioning means 58.

[0036] The above-described wiper motor 10 can be altered or modified in various ways without departing from the concept of the invention.Reference signs

[0037] 10 Wiper motor

[0038] 12 Housing

[0039] 14 Transmission housing

[0040] 16 Transmission cover

[0041] 18 Motor housing

[0042] 20 Electric motor

[0043] 22 Stator

[0044] 24 Longitudinal axis

[0045] 26 Rotor

[0046] 28 Drive shaft

[0047] 29 Toothing region

[0048] 30 Opening

[0049] 31 Bearing device

[0050] 32 Bearing device

[0051] 34 Bearing receptacle

[0052] 35 Bearing receptacle

[0053] 36 Transmission wheel

[0054] 37 Toothing

[0055] 38 Output shaft

[0056] 40 Connecting element

[0057] 42 Stator wire

[0058] 44 Connection plug

[0059] 46 Latching tongue

[0060] 48 Fastening screw

[0061] 50 Fastening flange

[0062] 52 Mating flange

[0063] 54 Blind bore

[0064] 55 Threaded portion

[0065] 56 Centring region

[0066] 58 Positioning means

[0067] 59 Extension

[0068] 61 Stop surface

[0069] 62 Stop surface

[0070] 63 Base

[0071] 64 Clearance

[0072] 66 Through-bore

[0073] 68 Radial gap

[0074] 70 Seal web

[0075] 72 Seal groove

[0076] 74 Gap

[0077] 75 Sealing element

[0078] 76 Seal medium

[0079] 78 Insulation

[0080] 79 Cutout

[0081] 80 Extension

[0082] d Outer diameter

[0083] D Inner diameter

Claims

Wiper motor (10) for a vehicle, comprising a housing (12) having a transmission housing (14) and a motor housing (18), wherein the motor housing (18) and the transmission housing (14) are connected to one another, wherein the motor housing (18) serves to accommodate an electronically commutated electric motor (20) which projects with a drive shaft (28) into the transmission housing (14), wherein the drive shaft (28) is mounted in the transmission housing (14) by means of a first bearing device (31) and in the motor housing (18) by means of a second bearing device (32), wherein the electric motor (20) has a rotor (26) which is arranged so as to be rotatable about a longitudinal axis (24), connected to the drive shaft (28) and surrounded by an annular stator (22), wherein the stator (22) is arranged in a defined first rotation angle position in relation to the longitudinal axis (24) in the motor housing (18), wherein the connection between the motor housing (18) and the transmission housing (14) is effected by a plurality of fastening screws (48), wherein the transmission housing (14) and the motor housing (18) are oriented with respect to one another in a defined second rotation angle position in relation to the longitudinal axis (24) by positioning means (58), wherein the positioning means (58) comprises extensions (59) which are arranged on the transmission housing (14) or / and on the motor housing (18) and engage in opposing openings (56) on the motor housing (18) and / or on the transmission housing (14).Wiper motor according to Claim 1, characterized in that the fastening screws (48) and the extensions (59) and the openings (56) are arranged concentrically with respect one another.Wiper motor according to Claim 2, characterized in that the extensions (59) are designed in the shape of a sleeve with a through-bore (66) through which the fastening screws (48) project.Wiper motor according to Claim 3, characterized in that a radial gap (68) is formed between the through-bore (66) in the extension (59) and the fastening screw (48).Wiper motor according to Claim 3 or 4, characterized in that the sleeve-shaped extension (59) is formed on a fastening flange (50) and the opening (56) is formed on a mating flange (52), wherein cooperating stop surfaces (61, 62) are formed on the fastening flange (50) and on the mating flange (52), said stop surfaces serving to form an axial stop between the motor housing (18) and the transmission housing (14) in the direction of the longitudinal axis (24).Wiper motor according to any of Claims 1 to 5, characterized in that two fastening screws (48) are provided, which are arranged offset relative to one another at least approximately by 180° in relation to the longitudinal axis (24).Wiper motor according to any of Claims 1 to 6, characterized in that the transmission housing (14) or the motor housing (18) has a seal web (70) which runs radially around the longitudinal axis (24) and engages in a seal groove (72) which runs radially around the longitudinal axis (24), wherein a gap (74) between the seal web (70) and the seal groove (72) is filled by a sealing element (75).Wiper motor according to Claim 7, characterized in that the sealing element (75) is a seal medium (76) which is liquid or paste-like in the processing state.Wiper motor according to Claim 7 or 8, characterized in that the seal web (70) and the seal groove (72) are arranged radially within the fastening screws (48) and the positioning means (58) in relation to the longitudinal axis (24).Wiper motor according to any of Claims 1 to 9, characterized in that the motor housing (18) and the transmission housing (14) are in the form of aluminium die cast parts, and in that the openings (56) and extensions (59) are mechanically processed in order to form a push fit.Wiper motor according to any of Claims 1 to 10, characterized in that, in order to obtain the first rotation angle position, an extension (80) is integrally formed on the motor housing (18), said extension form-fittingly cooperating with a cutout (79) formed on the stator (22).Wiper motor according to Claim 11, characterized in that a plurality of cutouts (79) are formed on the stator (22) in order to be able to position the stator (22) in the motor housing (18) in at least two different first rotation angle positions.Wiper motor according to any of Claims 1 to 12, characterized in that the stator (22) can be electrically contacted by way of a connecting element (40) which is arranged on the stator (22), projects into the transmission housing (14) and there is contacted with connection lines which are arranged in a transmission cover (16) and lead into a connection plug (44), wherein the transmission cover (16) closes the transmission housing (14).

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