Transmission drive assembly

The invention relates to a transmission drive assembly (10) having a drive motor (11) the drive shaft (23) of which protrudes with a portion (25) thereof into a transmission housing (12), wherein the drive shaft (23) is arranged on the side facing the transmission housing (12) in a bearing (32) which is held in a form-fit or force-closed manner in a substantially sleeve-shaped holding element (35; 65) which is arranged in a holding fixture (27) of the transmission housing (12). According to the invention, in an installation position for introducing and positioning the holding element (35; 65) in the holding fixture (27) of the transmission housing (12), the holding element (35; 65) is positioned in a first axial end position defined by an abutment element (30) of the drive motor (11), and, in an end position of the drive shaft (23) in the transmission housing (12), the holding element (35; 65) can be slid by means of a sliding element (47; 61; 62, 63) on the drive shaft (23) into a second axial end position which is axially remote from the at least one abutment element.

BACKGROUND OF THE INVENTION

The invention relates to a transmission drive assembly.

A bearing device for use in a transmission drive assembly is disclosed in the German patent specification DE 10 2009 028 133 A1 of the applicant. In the bearing device, a bearing that serves to mount the armature shaft of an electric drive motor is accommodated in a sleeve-shaped holding element, which in turn can be inserted into a holding fixture of a housing, in particular a transmission housing. In so doing, the bearing is accommodated in the holding element in a form-fit or force-closed manner.

In order to install the drive motor on a housing of a transmission drive assembly, it is known from practice to dispose a holding element in a first axial end position. Said first end position is achieved by pressing the holding element against an abutment element, in particular against a part that is at least indirectly coupled to a brush device of the drive motor. The problem with this is that the holding element tends to make noise in said end position during the operation of the transmission drive assembly and also mechanically stresses the brush device.

SUMMARY OF THE INVENTION

Based on the prior art described above, the aim underlying the invention is to develop a transmission drive assembly in such a way that a simple installation process is achieved by means of the constructive embodiment of the transmission drive assembly; thus enabling a secure and defined end position of the holding element to be achieved after installation on or in the transmission housing. At such an end position, noises are reduced and the mechanical stress on the brush device is reduced by means of the holding element being axially spaced apart from the brush device. A transmission drive assembly inventively meets the aforementioned aim in that, in an installation position for introducing and positioning the holding element in the holding fixture of the transmission housing, the holding element is positioned in a first axial end position defined by an abutment element of the drive motor, and in that, in an end position of the drive shaft in the transmission housing, the holding element can be slid by means of a sliding element on the drive shaft into a second axial end position which is axially remote from the at least one abutment element. In other words, this means that, in order to install the drive motor on the transmission housing, the holding element initially assumes a defined first target position from which said holding element is brought during the installation into the second, final target position. By means of these two target positions, defined positions of the holding element and consequently the bearing device are thus produced on the drive shaft, which positions facilitate a particularly reliable installation process and moreover prevent the aforementioned disadvantages of the prior art.

In order to achieve the first axial end position of the holding element, provision is made in a design implementation of the invention for the holding element to abut on the side facing away from the holding fixture of the transmission housing with an end face thereof at least indirectly against a device, in particular a brush holder device of the drive motor, that acts as an abutment element and is disposed on the drive shaft in an axially fixed manner. The already available brush holder or a retaining ring for the brush holder is thus used as an abutment element for the holding element.

Provision is made in this case in a particularly preferred manner for the holding element to comprise a flange-like circumferential edge which forms the end face and for said edge to interact with at least one retaining element that delimits a displaceability of the holding element on the drive shaft. As a result, a particularly secure or planar abutment of the holding element against the device (brush holder or retaining ring) is facilitated on the one hand; while, on the other hand, the holding element can be reliably prevented from detaching from the drive shaft or getting lost during installation.

In order to achieve a defined target position of the bearing device on the drive shaft in the second axial end position and on the other hand to keep the displacement forces for the holding element to achieve the second end position as small as possible, provision is additionally made in a further advantageous embodiment for the bearing to be axially fixed in the holding element and to be disposed on the drive shaft in an axially displaceable manner.

In order to achieve the axial displaceability of the holding element on the drive shaft by means of the sliding element, it is proposed that the holding element comprises a radially circumferential wall and that at least one recess is formed in the wall, said recess interacting with the sliding element to axially displace said holding element.

In a particularly simple manner, a displacement of the holding element is brought about if the sliding element or the recess comprises at least one chamfer which causes an axial displacement of the holding element by the action of the sliding element thereon.

In an embodiment which is advantageous in terms of costs and manufacturing technology, it is proposed that the holding element is embodied as a deep drawn component and the recess as an opening and that the at least one chamfer is formed on the sliding element.

An embodiment of the invention is very particularly preferred in which the sliding element is a constituent part of the transmission housing, in particular a cover element of the transmission housing. In so doing, additional, separate components required for sliding the holding element are, on the one hand, not needed; and, on the other hand, it can be ensured by a corresponding configuration of the transmission housing or the cover element that the holding element achieves the target position thereof after the cover element has been installed.

As an alternative, it is however also conceivable that the sliding element is embodied as a component that is separate from the transmission housing. Such an embodiment has the advantage that the arrangement or configuration of the recess on the holding element can occur independently, for example, of the disposal of the cover element.

In order to furthermore design the installation process in a particularly simple and reliable manner, provision can be made for the holding fixture in the transmission housing to be delimited by a wall, in which an opening is configured, and for the opening to be arranged in alignment with the recess and to form a guideway for the sliding element.

DETAILED DESCRIPTION

Identical components or components serving the same function are provided with the same reference numerals in the figures.

InFIG. 4, the essential components of a transmission drive assembly10according to the invention are depicted as they serve as a constituent part of a comfort and convenience drive, for example of a window regulator drive, a sunroof drive, a seat adjustment drive or the like, in a motor vehicle. The transmission drive assembly10comprises a drive motor11which is designed as a (mechanically commutated) electric motor and is connected to a drive housing12or is flange-mounted to the same. The transmission housing12has, for example, a shell-like lower part13, the open top side of which can be closed by means of two separate transmission housing covers14,15(depicted as housing cover14inFIG. 4), in particular by means of screw or detent connections that are not individually depicted in detail.

The transmission housing12also comprises an opening17which only by way of example is in alignment with the longitudinal axis of the drive motor11and which serves as an insertion opening for inserting plug-in electronics comprising the plug disposed thereon for contacting to the wiring harness of the motor vehicle (not depicted). A single-stage or multi-stage transmission, which, as can be seen inFIG. 4, has a spur gear having external teeth19, is disposed within the transmission housing12. The spur gear18furthermore comprises a driving section21which protrudes from the transmission housing12at the upper side thereof and is connected at least indirectly to an element of the transmission drive assembly that is to be adjusted, in particular to a window pane or a seat.

The external teeth19of the spur gear18mesh with a toothed section22of a drive shaft23of the drive motor11. To this end, a portion25protruding from the housing24of the drive motor11protrudes into the transmission housing12, wherefore the transmission housing12, in the depicted exemplary embodiment the lower part thereof, comprises an annular holding fixture27in which the portion25of the drive motor11can be inserted.

As can especially be seen inFIGS. 1 and 2, the drive motor11comprises an armature that is disposed within the housing24and cannot be seen in the figures, wherein an armature shaft28simultaneously forms the drive shaft23. A brush holder device30can be mounted in an axial direction on the armature shaft28, said device being fixed in the axial position thereof in the housing24by means of an interference fit. A bearing32, e.g. in the form of a cup and ball bearing, is furthermore disposed on the armature shaft28, the axial position of which bearing is determined by a retaining ring21arranged on the armature shaft28. The bearing32is accommodated within a substantially sleeve-shaped holding element35that encompasses the bearing32on the outer circumference thereof in a form-fit and force-closed manner such that the bearing32is radially fixed within the holding element35. On the other hand, the inside diameter of the bearing32or the outside diameter of the armature shaft28is dimensioned in such a way that the bearing32can be axially displaced on the armature shaft28without the position thereof within the holding element35being thereby altered. The holding element35preferably consists of sheet metal and is designed as a deep drawn component. Finally a sleeve-shaped gear element36can be pushed onto the armature shaft28and is connected there, for example, by means of a press-fit or a laser weld, said gear element supporting the toothed section22.

The drive motor11described to this point can be connected in accordance withFIG. 3to the transmission housing12in the direction of the arrow37by the portion25of the drive shaft23being inserted into the holding fixture27. In accordance withFIG. 4, the spur gear18is subsequently mounted by being fitted onto an axis38within the transmission housing12, wherein the engagement is simultaneously produced between the external teeth19of the spur gear18and the toothed section22of the drive shaft23.

The condition is depicted inFIG. 5in which the drive shaft23of the drive motor11is situated shortly before attaining the axial end position thereof within the transmission housing12. In addition, the condition is also depicted inFIG. 5in which the holding element is situated in the installation position which occurs prior to introducing the portion25of the drive shaft into the transmission housing. It can particularly be seen that a radially circumferential, flange-like edge39of the holding element35abuts with an end face41against the opposing end face42of the brush holder device30. The holding element35is thus located in direct abutting contact with the brush holder device30. This position represents a first axial end position of the holding element35on the drive shaft23. Furthermore, the bearing32abuts against the retaining ring31.

A plurality of retaining elements in the form of detent hooks43, which are disposed at uniform angular distances to one another, engage behind the edge39of the holding element35. Said detent hooks delimit the axial mobility of the holding element35on the drive shaft23in a direction opposite to the brush holder device30.

A recess45can furthermore be seen in the wall of the holding element35on the side of the bearing32opposite to the edge39. Said recess is configured in the form of an opening and is aligned with the (open) opening of the lower part13of the transmission housing12. The annular holding fixture27of the transmission housing12has an opening46in a wall of said holding fixture27in alignment or superposition with the recess45. A sliding element in the form of a projection47protrudes through the opening46, said projection being integrally formed on the lower side of the second transmission housing cover15. The projection47has two bevels or chamfers48,49on the side thereof facing the opening46or, respectively, the recess45. Furthermore, the width of the projection47is matched to the width of the opening46such that the opening46forms a guideway for the projection47when introducing the transmission housing cover15into the opening46in accordance with the arrow51.

A condition is depicted inFIG. 5in which a chamfer48has just moved into abutting contact with the associated edge52of the recess45of the holding element35when mounting the transmission housing cover15corresponding to the direction of the arrow51. As can be seen with the aid ofFIG. 6, the projection47is completely introduced into the recess45when the transmission housing cover15is further pressed down in the direction of the arrow51. This results in the holding element35being moved axially on the armature shaft28in the direction of arrow53; thus enabling a gap to form between the end face41of the edge39and the opposing end face42of the brush holder device30. A decoupling of the holding element35from the brush holder device30is effected by the gap55which results in the holding element35being decoupled from noise and the brush holder device30being relieved of mechanical stress. InFIG. 6, the holding element35is consequently disposed in the axial (second) end position thereof on the armature shaft28. In particular by means of screwing or latching the transmission housing cover15to the lower part13of the transmission housing12, it is ensured during the operation of the transmission drive assembly10that this axial end position of the holding element35no longer changes.

In the exemplary embodiment of the invention depicted inFIGS. 5 and 6, the second axial end position of the holding element35is ensured by the sliding element which is configured in the form of a projection47and is integrally formed on the transmission housing cover15. In the exemplary embodiment depicted inFIG. 7, the sliding element is in contrast designed as component in the form of a bearing clamp60that is separate from the transmission housing cover15. The bearing clamp60has a projection61on the side of the holding element35facing the recess45, said projection interacting directly with the recess45, if applicable without guidance of an annular holding fixture27as is the case with the initially described exemplary embodiment.

Finally inFIG. 8, an exemplary embodiment is depicted in which an axial adjustment of the holding element65is effected by two pin-shaped elements63,64which engage in a radially circumferential annular groove66formed on the holding element65. To this end, corresponding holding bores for the elements63,64are, for example, formed in the lower part13of the transmission housing12; thus enabling said elements63,64to be inserted axially into the holding bores and thus axially position the holding element65on the armature shaft28. A transmission housing cover (not depicted) is subsequently placed on the lower part13, which, as the case may be, simultaneously secures the elements63,64. As an alternative, the elements63,64can also be disposed so as to be integrated into a housing cover (not depicted).

The transmission drive assembly10described to this point can be altered or modified in a variety of ways without deviating from the inventive concept. Said concept consists of effecting the axial (second) end position of the holding element35,65during installation in or on the transmission housing, wherein particularly good acoustic and/or mechanical properties of the transmission drive assembly10are achieved by means of the axial decoupling of the holding device35,65.