CN106402353B

CN106402353B - Transmission housing and transmission drive unit

Info

Publication number: CN106402353B
Application number: CN201610603185.4A
Authority: CN
Inventors: A.马蒂尼
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2015-07-29
Filing date: 2016-07-28
Publication date: 2021-03-09
Anticipated expiration: 2036-07-28
Also published as: FR3039617B1; FR3039617A1; CN106402353A; DE102015216653A1

Abstract

The invention relates to a gear drive unit (8), in particular for a motor vehicle seat adjustment gear, and to a gear housing (10), having a housing base body (12) and a housing cover (11) with a circumferential wall (15), and having a locking mechanism (20) for fastening the housing cover (11) to the housing base body (12), wherein a plurality of locking elements (22) are arranged on a radial inner side (16) of the circumferential wall (15), which can be locked with a counter locking element (24) on a radial outer wall (14) of the housing cover (11).

Description

Transmission housing and transmission drive unit

Technical Field

The invention relates to a gear housing, in particular for a seat adjustment drive in a motor vehicle, and to a gear drive unit comprising such a gear housing.

Background

Known gear housings for vehicle seat adjusting devices are formed from a housing base body and a housing cover, which are trough-shaped. The most different solutions exist for fastening the housing cover to the housing base body. For example, it is known to fasten the housing cover to the housing base body by means of screws and/or by means of snap hooks.

DE 102007044351 a1 discloses a transmission housing in which a housing cover is fastened to a housing base only by means of hooks. The latching hooks arranged on the housing base project axially beyond the circumferential wall of the housing base. The housing cover is formed with spring washers in the circumferential direction, which spring washers project radially outward from the circumferential wall. Although in this solution, the screw connection can be additionally omitted, this snap connection requires additional radial and axial installation space.

Disclosure of Invention

The object of the present invention is to provide a gear housing which is optimized with regard to installation space and which can be produced and installed in a simple manner. This object is achieved by a transmission housing:

the gear housing has a housing base body with a circumferential wall and a housing cover and has a locking mechanism for fastening the housing cover to the housing base body. According to the invention, a plurality of locking elements are arranged on the radial inner side of the circumferential wall, which locking elements can be locked with the abutment locking elements on the radial outer wall of the housing cover, wherein a recess for the locking elements is formed in the radial outer side of the housing cover axially adjacent to the abutment locking elements, which recess extends in the axial direction by the axial spring deflection of the gear mechanism component inserted into the gear mechanism housing.

The invention also relates to other advantageous further embodiments. All combinations of at least two of the features described in the application documents such as the description and/or the drawings are also within the framework of the invention.

The gear housing according to the invention and the drive unit comprising this gear housing have the advantage over the prior art that the axial overall height is reduced by the arrangement of the locking elements and the counter locking elements in the gear housing, by approximately the thickness of the axial cover wall. The radial extent in the circumferential wall also decreases, since the complete latching connection is arranged radially within the circumferential wall. The required installation space on the user interface with the mounting flange can thus be reduced. No additional connecting elements or mounting steps are required to close the gear housing.

The embodiments described above can be advantageously expanded in design and improved by further measures. By making the outer diameter of the gear cover smaller than the inner diameter of the circumferential wall (apart from the stop elements and the abutment stop elements), the housing cover can be accommodated completely in the housing base body, so that the housing cover does not project beyond the circumferential wall in the radial direction.

For transporting the transmission drive unit, the housing cover projects in the axial direction beyond the circumferential wall. However, if the drive unit is fixed to the mounting flange, the cover surface is pressed in axially until it rests flush against the circumferential wall on the mounting flange. The axial installation space is therefore still limited to the axial extent of the circumferential wall of the housing base.

Since the latching elements are formed axially spaced apart from the circumferential wall and the front face of the housing cover, the latching connection is completely within the housing and cannot be seen from the outside. The latching connection which is concealed in this way can therefore also be constructed so as not to be able to be released without being destroyed.

The stop elements as stop projections and counter-stop projections can be produced in one piece with the base body and the housing cover, in particular by injection molding, from a production engineering standpoint. The simple geometry as a stop projection also allows the injection mold to be produced very simply and cost-effectively. By selecting the material thickness of the housing cover and the circumferential wall, the elasticity can be adjusted accordingly in the radial direction of the stop element or the counter stop element.

In a preferred embodiment, the stop element and the counter stop element extend over a circle segment covering at least 30 °. For example, two diametrically opposed stop elements and also abutment stop elements are arranged, which extend over an angular range of approximately 80 ° to 100 °. Due to the larger circumference, the latching projections can be correspondingly configured with a very small overlap in the radial direction, so that the installation force of the cover is significantly reduced.

In this case, the elastic design of the radial outer or circumferential wall of the cover is adapted to the radial overlap of the stop surfaces between the stop projection and the counter-stop projection, so that the gear housing has sufficient stability.

The radial recess, which is open in the axial direction, can optionally be formed in the radial outer wall of the housing cover, which increases the radial mobility of the radial outer wall.

If recesses extending in the axial direction are formed in the radial outer wall or in the circumferential wall, the stop elements or the counter-stop elements can be moved relative to one another in the axial direction after their stopping. The latching connection can therefore be used on the one hand as a transport safeguard for the drive unit of the gear mechanism and, when the drive flange is connected to the fastening flange, the housing cover is pressed axially into the circumferential wall without the latching connection having to be released again.

A spring element is arranged inside the gear housing, which spring element holds the housing cover under prestress. The stop surfaces of the stop element and the counter-stop element are thus pressed against one another, wherein the forces acting on the housing cover are reduced during transport. The housing cover is then pressed axially against this spring force into the circumferential wall when the drive unit is fixed to the fixing flange until the axially outer surface of the cover rests flush against the front face of the circumferential wall on the fixing flange.

The latching connection can be configured as an unreleasable connection if the latching surfaces of the latching element and the mating latching element are configured approximately perpendicular to the axial direction. However, if the latching surfaces are inclined relative to the axial direction, the latching connection can also be released again if the necessary pulling force is exerted on the cover.

The gear can advantageously be designed as a worm gear, in which a worm is arranged on the armature shaft of the electric motor, which worm meshes with a corresponding worm wheel mounted in the gear housing. In order to decelerate the rotation of the worm gear, an eccentric gear or a planetary gear can additionally be arranged in the gear housing. In this case, a driven element is arranged on the gear mechanism part, which driven element projects outward through a central opening in the housing cover. In this way, an extremely compact drive unit with a large reduction ratio can be achieved, wherein the individual gear components are axially supported by the fastening of the housing cover in the housing base body.

The gear mechanism has, for example, a rotationally fixed slide valve in which an eccentric is preferably guided. The slide valve is supported in a radial recess in the circumferential wall. The housing cover accordingly has radial projections which close the recesses of the circumferential wall after the mounting of the housing cover on the housing base body. The partial annular snap connection according to the invention is therefore also used for cover elements which are not completely round but only over a certain angular range. In order to apply an axial spring force pressing the housing cover from the inside outwards, a spring element acting in the axial direction is arranged inside the gear housing. The spring element can be configured particularly simply as a closed ring, which completely surrounds the shaft of the worm wheel. Such a spring element can be inserted, for example, axially between the bottom of the housing base and the worm wheel, so that all the gear components are tensioned from the inside toward the housing cover by the axial spring force.

The drive unit is made lighter by saving material. It is not necessary to take into account axial installation tolerances, since the transmission components are naturally positioned precisely in the axial direction when they are mounted on the mounting flange. Particularly advantageous is an embodiment of the gear housing in which, apart from the locking means and, if appropriate, the centering projection, no further fastening means, such as screws or the like, are provided for fastening the housing cover to the housing base body, which is in particular of channel-shaped design.

Drawings

Embodiments of the invention are illustrated in the drawings and are explained in detail in the following description.

In the drawings:

fig. 1 shows a transmission drive unit according to the invention before installation;

FIG. 2 shows an unsealed housing base according to the invention;

fig. 3 shows a gear mechanism according to the invention with a housing cover; and

fig. 4a and b show a section through a transmission housing according to the invention before and after installation in a motor vehicle.

Detailed Description

Fig. 1 shows a seat adjustment drive as a gear drive unit 8, which is fastened, for example, to a side wall 61 of the seat frame. This frame surface of the seat forms a mounting flange 60 for the transmission drive unit 8. The electric motor 54 drives a worm 69 via an armature shaft, which in turn drives a worm wheel 68 supported in the gear housing 10. This worm gear 64 transmits the drive torque via a driver to a driven pinion 70, which acts through a recess in the mounting flange 60 and is in operative connection with the seat part to be adjusted (for example the seat surface or the seat backrest), for example via a corresponding toothed ring and/or via a flexible shaft. The housing cover 11 is pre-fastened in the housing base 12 via the partial annular snap connection 20 and is only moved into its final axial position when it is mounted on the mounting flange 60. The gear drive unit 8 is screwed to the mounting flange 60, for example, with screws as connecting elements 58. For this purpose, the connecting element 58 is inserted through a bore 59 in the mounting flange 60 and is fixed to the fastening dome 56, in particular by means of self-tapping screws, into the plastic material of the gear housing 10. In fig. 1, before the transmission drive unit 8 is screwed onto the mounting flange 60, this mounting flange 60 is shown by a dashed line, wherein the mounting flange is spaced apart from the outer cover surface 13 of the housing cover 11 by the spring deflection 50. After installation, both the front face 18 of the circumferential wall 15 of the housing base body 12 and the outer cover 13 are in axial contact with the mounting flange 60. The housing cover 11 is pressed axially against the mounting flange 60 by means of a spring element 51, which is arranged between the bottom face 49 of the housing base body 12 and the gear component 52, in particular the worm 68, in the gear housing 10. The gear mechanism component 52 is therefore moved into its correct axial operating position when the motor vehicle is installed. The fastening dome 56 is preferably formed in one piece with the housing base 12 by means of die casting.

Fig. 2 shows only the hollow housing base body 12, on the bottom face 49 of which an axial spring element 51 is mounted. Centrally along the axis 66, a shaft 67 is arranged, which is fixed to the housing and on which the gear mechanism component 52 is supported. As the latching elements 22, latching projections 23 are formed on the inner side 16 of the circumferential wall 15 of the housing base body 12, which projections extend over a certain angular range 32 in the circumferential direction. For example, two partially annular stop elements 22 can be formed, which each extend over more than approximately 90 ° past the approximately circular inner circumference of the circumferential wall 15. In this embodiment, the circumferential wall 15 is initially of approximately rigid design, so that the housing cover 11 is correspondingly of radially flexible design for its locking in the circumferential wall 15.

Fig. 3 shows the gear mechanism supported in the gear mechanism housing 10 together with the housing cover 11. Worm gear 68 has an invisible eccentric that pushes eccentric gear 78 into eccentric motion. In order to roll the ring gear 79, which is fixedly connected to the output pinion 70, on the eccentric gear 78, the eccentric gear 78 is guided by means of a slide valve 76, which is mounted in a rotationally fixed manner in the housing base body 12. For this purpose, several radial recesses 80 are formed in the housing base body 12, in which the slide valve 76 engages in the radial direction. The ring gear 79 is covered by the housing cover 11, wherein the axial projection with the pinion 70 has a cylindrical bead 71 against which the edge of the bore 72 in the housing cover 11 rests. The housing cover 11 has several radial projections 82, which cover corresponding radial recesses 80 in the housing base body 12. A spring ring 51 is arranged below the worm wheel 68, which spring ring tensions the gear member 52 of the gear in the axial direction between the bottom surface 49 and the inside of the housing cover 11 after the gear has been installed. The spring element 51 is configured, for example, as a bellows ring, which encloses the shaft 67 in a closed manner. The spring force is minimal or zero in the transport position of the transmission drive unit 10 and only increases when the mounting flange 60 is mounted on due to the axial pressing-in of the housing cover 11, so that the transmission component 52 is precisely positioned in the axial direction by the axial spring force. Formed on the housing cover 11 are a plurality of counter-latching elements 24 which form a latching connection 20 with the latching elements 22 of the housing base body when the housing cover 11 is inserted into the housing base body 12. The abutment stop elements 24 are likewise in the form of radial abutment stop projections 25 which extend in the circumferential direction over an angular range 32, which likewise exceeds approximately 2 × 90 °. In this case, an axial slot 36 is formed on the outer circumference of the housing cover 11, which slot, with the abutment stop 25 of the outer wall 14, provides a certain radial flexibility of the outer wall. In this exemplary embodiment, an axial pin 37 formed on the housing base body 12 engages in the cutout 36.

Fig. 4a shows a section through the gear housing 10 before installation and fig. 4b shows a section after installation. The stop projection 23 and the counter stop projection 25 have a lead-in

phase

26, 28, respectively, so that the stop element and the counter stop element 22, 24 are slidingly moved into their stop position when the housing cover 11 is moved axially in. In addition to the abutment stop projection 25, a recess 44 is formed in the housing cover 11 in the axial direction, in which recess the stop projection 23 can be moved axially, in particular without being clamped. In this state according to fig. 4a, the housing cover 11 prevents loss during transport. In this case, the housing cover 11 is pressed axially outward by the spring element 51, not shown here, so that the stop surfaces 84 formed on the stop element and the counter-stop element 22, 24 abut against each other. Due to the radial orientation of the stop surfaces 84 of the stop element and the counter-stop element 22, 24, which bear against one another, the locking connection 20 is designed to be non-releasable and to be secured against loss. In the alternative, the inclined stop surface 85 can be configured to be inclined to the axial direction 30, so that the stop connection 20 can also be configured to be releasable. When the transmission drive unit 8 is installed according to fig. 4b, the housing cover 11 is pressed into the housing base body 12 to the extent of the spring deflection 50, so that the housing cover 11 no longer protrudes from the housing base body 12 but rather bears axially against the mounting flange 60. The outer cover surface 13 of the housing cover 11 is therefore flush with the front surface 18 of the circumferential wall 15. In this case, the locking projection 22 is guided axially in the recess 44. The stop surfaces 84 then no longer bear against one another in the operating state, so that the detent connection 20 can be designed for only minimal loading during transport (loss prevention).

It is to be noted that various combinations of the individual features with respect to one another are possible with respect to the exemplary embodiments shown in the figures and described in the description. The specific configuration of the stop elements and the abutment stop elements 22, 24 and their number and angular extent can thus vary. The latching connection 20 is of the type designed as a partial annular snap connection, but in this case the latching element is also of flexible design or can be designed with recesses in the circumferential wall. Instead of an eccentric gear or a planetary gear, other gear configurations can also be arranged in the gear housing in order to transmit the drive torque of the electric motor to the part to be set via the output element 70. The invention is particularly suitable for adjusting moving parts in a motor vehicle, in particular seat parts, wherein the transmission drive unit is preferably flanged on the side of the vehicle seat.

Claims

1. A gear housing (10) having a housing base body (12) and a housing cover (11) with a circumferential wall (15), and having a locking mechanism (20) for fastening the housing cover (11) to the housing base body (12), characterized in that a plurality of locking elements (22) are arranged on a radial inner side (16) of the circumferential wall (15), which locking elements can be locked with a counter locking element (24) on a radial outer wall (14) of the housing cover (11), wherein a recess (44) for the locking element (22) is formed in a radial outer side (17) of the housing cover (11) axially adjacent to the counter locking element (24), which recess extends in an axial direction (30) by an axial spring deformation (50) of a gear component (52) inserted into the gear housing (10).

2. The gear housing (10) according to claim 1, characterized in that the housing cover (11) can be inserted in the axial direction (30) completely within the circumferential wall (15) of the housing base body (12) in the axial direction for assembly.

3. The gear housing (10) according to claim 1 or 2, wherein the housing cover (11) has an outer, axial cover face (13) which, in the installed state in the motor vehicle, ends flush with an axial front face (18) of the circumferential wall (15) and does not project beyond this front face in the axial direction.

4. The gear housing (10) according to claim 1 or 2, wherein the stop element (22) is formed on the inner side (16) of the circumferential wall (15) axially spaced apart from the axial front face (18), and the counter stop element (24) is formed on the radial outer side (17) of the radial outer wall (14) of the housing cover (11) axially spaced apart from the axial outer cover face (13).

5. The gear housing (10) according to claim 1 or 2, wherein the latching element (22) is formed integrally with the circumferential wall (15) as a radial latching projection (23) and the counter-latching element (24) is formed integrally with the housing cover (11) as a radial counter-latching projection (25), the latching projection and the counter-latching projection each having a guide phase (26, 28) which slides past each other in the axial direction during latching.

6. Transmission housing (10) according to claim 1 or 2, characterized in that the stop element (22) and the abutment stop element (24) are configured partially annularly, wherein they extend over an angular range (32) of more than 30 °.

7. The gear housing (10) according to claim 1 or 2, wherein the housing cover (11) is configured to be radially flexible, such that a radially outer wall (14) of the housing cover can be elastically deformed radially inwardly when inserted into the housing base body (12), the deformation being at least as great as a radial overlap (34) of the locking projection (23) with the counter locking projection (25) in the radial direction, and the radially outer wall (14) has a slot (36) which is open in the axial direction.

8. Transmission housing (10) according to claim 6, characterized in that said angular range (32) is about 70 ° to 100 °.

9. A gear drive unit (8) having a gear housing (10) according to one of the preceding claims, wherein the gear housing (10) accommodates a plurality of gear components (52) which are driven by an electric motor (54), characterized in that the gear components (52) are tensioned against a housing cover (11) by means of axially acting spring elements (51), wherein, in the state in which the gear drive unit (8) is not installed, an outer, axial cover face (13) projects beyond an axial front face (18) of the circumferential wall (15).

10. The gear mechanism drive unit (8) according to claim 9, characterized in that a screw-on dome (56) is formed on the housing base body (12), which screw-on dome, in the installed state of the gear mechanism drive unit (8), receives a connecting element (58) which presses the front face (18) against the mounting flange (60) and presses the housing cover (11) into the housing base body (12) against the spring force of the spring element (51), wherein the outer, axial cover face (13) also bears axially elastically against the mounting flange (60).

11. A transmission drive unit (8) according to claim 9 or 10, wherein the transmission member (52) forms a worm gear (64) in which a worm wheel (68) supported on a housing-fixed shaft (66) meshes with a worm (69) driven by the motor (54), and a driven pinion (70) operatively connected to the worm wheel (68) projects outwardly from an aperture (72) in the housing cover (11).

12. The gear mechanism drive unit (8) according to claim 9 or 10, characterised in that the gear mechanism component (52) forms a planetary gear mechanism (74), in which a slide (76) for guiding an eccentric gear (78) is supported in a rotationally fixed manner in a radial recess (80) of the housing base body (12).

13. The gear drive unit (8) according to claim 12, wherein the housing cover (11) has a radial projection (82) which sealingly closes the radial recess (80) in the axial direction (30).

14. The gear mechanism drive unit (8) according to claim 9 or 10, characterized in that the spring element (51) is configured in an annular shape and is arranged axially between the bottom (49) of the housing base body (12) and the worm gear (68).