Spindle drive for an adjustment element of a motor vehicle

Abstract

A spindle drive for an adjustment element of a motor vehicle is provided. The spindle drive has a drive unit and a spindle-spindle nut transmission arranged downstream of the drive unit in terms of drive for generating linear drive movements. The drive unit has a tubular drive unit housing and therein a drive motor. In some cases an intermediate transmission is arranged downstream of the drive motor in terms of drive. The drive unit and the spindle-spindle nut transmission are arranged one behind the other on the geometrical spindle axis, and a spindle drive housing is provided with a tubular inner housing and a tubular outer housing. The inner housing runs in a telescope-like manner in the outer housing. In some cases the outer housing of the spindle drive housing accommodates the drive unit with the drive unit housing and is connected to the drive unit.

Claims

1. A spindle drive for an adjustment element of a motor vehicle, comprising: a drive unit and a spindle-spindle nut transmission arranged downstream of the drive unit in terms of drive for generating linear drive movements, wherein the drive unit comprises a tubular drive unit housing and therein a drive motor, wherein the drive unit and the spindle-spindle nut transmission are arranged one behind the other on a geometrical spindle axis; a spindle drive housing comprising a tubular inner housing and a tubular outer housing, wherein the tubular inner housing runs in a telescopic manner in the tubular outer housing; and two connections for transferring the linear drive movements, wherein a first of the two connections is connected to the drive unit and wherein a second of the two connections is connected via a guide tube to a spindle nut; wherein the tubular outer housing of the spindle drive housing accommodates the drive unit with the drive unit housing and is connected to the drive unit; wherein the tubular inner housing, in a fully retracted state, overlaps with an axial overlapping portion of the drive unit; wherein the tubular inner housing, in a fully extended state, does not overlap with the drive unit; and wherein the guide tube is a separate element from the inner housing.

2. The spindle drive as claimed in claim 1, wherein an axial extension of the drive unit housing is at least the axial extension of the drive motor and is smaller than 150% of the axial extension of the drive motor together with an intermediate transmission.

3. The spindle drive as claimed in claim 1, wherein the tubular outer housing is primarily composed of a first material and the drive unit housing is primarily composed of a second material, and wherein the second material is harder than the first material, and/or is less flexible than the first material, and/or has a higher toughness than the first material, and/or is a metallic material while the first material is a plastic material.

4. The spindle drive as claimed in claim 1, wherein the tubular inner housing and/or the tubular outer housing always lie outside a flow of a drive force.

5. The spindle drive as claimed in claim 1, wherein the drive unit housing has, in the region of the overlapping portion, a reduced diameter in comparison with the rest of the drive unit housing.

6. The spindle drive as claimed in claim 5, wherein an intermediate transmission is arranged in the overlapping portion.

7. The spindle drive as claimed in claim 1, wherein an anti-rotation lock is provided between the two connections by a positive lock between the spindle nut or the guide tube and a torque tube fixed on the drive unit, or by a positive lock between the tubular inner housing and the tubular outer housing.

8. The spindle drive as claimed in claim 1, wherein an axial connecting portion of the drive unit housing is in engagement with the tubular outer housing via a spacer arrangement which generates a radial drainage gap between the connecting portion and the tubular outer housing.

9. The spindle drive as claimed in claim 8, wherein the spacer arrangement is formed from a web arranged on the connecting portion of the drive unit housing.

10. The spindle drive as claimed in claim 1, wherein the tubular inner housing has a covering cap on an end portion of the tubular inner housing distant from the drive unit, wherein the covering cap, when the tubular inner housing is in the fully retracted state, is in sealing engagement with an end portion of the tubular outer housing distant from the drive unit, and wherein the covering cap is not in engagement with an end portion of the tubular outer housing in an extended state.

11. The spindle drive as claimed in claim 1, further comprising an intermediate transmission arranged downstream of the drive motor in terms of drive.

12. The spindle drive as claimed in claim 11, wherein an axial extension of the drive unit housing is at least the axial extension of the drive motor together with the intermediate transmission and is smaller than 150% of the axial extension of the drive motor together with the intermediate transmission.

13. The spindle drive as claimed in claim 1, wherein the tubular inner housing has a covering cap on an end portion of the tubular inner housing distant from the drive unit and wherein the covering cap provides at least one drainage recess for drainage of the tubular inner housing.

14. The spindle drive as claimed in claim 1, wherein the guide tube is connected to the inner housing.

15. A flap arrangement for a motor vehicle, comprising: a flap, and a spindle drive for adjusting the flap, the spindle drive comprising: a drive unit and a spindle-spindle nut transmission arranged downstream of the drive unit in terms of drive for generating linear drive movements, wherein the drive unit comprises a tubular drive unit housing and therein a drive motor, wherein the drive unit and the spindle-spindle nut transmission are arranged one behind the other on a geometrical spindle axis; a spindle drive housing comprising a tubular inner housing and a tubular outer housing, wherein the tubular inner housing runs in a telescopic manner in the tubular outer housing; and two connections for transferring the linear drive movements, wherein a first of the two connections is connected to the drive unit and wherein a second of the two connections is connected via a guide tube to a spindle nut; wherein the tubular outer housing of the spindle drive housing accommodates the drive unit with the drive unit housing and is connected to the drive unit; wherein the tubular inner housing, in a fully retracted state, overlaps with an axial overlapping portion of the drive unit; wherein the tubular inner housing, in a fully extended state, does not overlap with the drive unit; and wherein the guide tube is a separate element from the inner housing.

16. The flap arrangement as claimed in claim 15, wherein the tubular inner housing has a covering cap on an end portion of the tubular inner housing distant from the drive unit; wherein the covering cap lies in an upper region of the spindle drive, in a case of a fully retracted spindle drive and a closed flap; and wherein the covering cap is in sealing engagement with an end portion of the tubular outer housing distant from the drive unit in the case of the fully retracted spindle drive and the closed flap.

17. The flap arrangement as claimed in claim 15, wherein the tubular inner housing has a covering cap on an end portion of the tubular inner housing distant from the drive unit; wherein the covering cap lies in a lower region of the spindle drive, in a case of a fully retracted spindle drive and a closed flap; and wherein the covering cap provides at least one drainage recess for drainage of the tubular inner housing.

18. The flap arrangement as claimed in claim 15, wherein an axial connecting portion of the drive unit housing is in engagement with the tubular outer housing via a spacer arrangement which generates a radial drainage gap between the axial connecting portion and the tubular outer housing.

19. A spindle drive for an adjustment element of a motor vehicle, comprising: a drive unit, the drive unit comprising a tubular drive unit housing and a drive motor within the drive unit housing; a spindle-spindle nut transmission arranged downstream of the drive unit in terms of drive for generating linear drive movements, the drive unit and the spindle-spindle nut transmission arranged one behind the other on a geometrical spindle axis; a spindle drive housing comprising a tubular inner housing and a tubular outer housing, the tubular inner housing running in a telescopic manner in the tubular outer housing; and a first connection that is connected to the drive unit and a second connection that is connected via a guide tube to a spindle nut of the spindle-spindle nut transmission, for conducting the linear drive movements apart from the spindle drive housing; wherein the tubular outer housing is connected to the drive unit and accommodates the drive unit with the drive unit housing; wherein the tubular outer housing is primarily composed of a plastic material and the drive unit housing is primarily composed of a metallic material; wherein the tubular inner housing, in a fully retracted state, overlaps with an axial overlapping portion of the drive unit; wherein the tubular inner housing, in a fully extended state, does not overlap with the drive unit; and wherein the guide tube is a separate element from the tubular inner housing.

20. The spindle drive as claimed in claim 19, wherein the tubular outer housing fully overlaps with the drive unit along the geometrical spindle axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained in greater detail below on the basis of a drawing which represents only one exemplary embodiment. In the drawing

(2) FIG. 1 shows, in a schematic side view, the rear end of a motor vehicle with a spindle drive according to the proposal,

(3) FIG. 2 shows the spindle drive according to FIG. 1 in an outer view (View A)) and in a partial exploded view (View E)),

(4) FIG. 3 shows the spindle drive according to FIG. 1 in a longitudinal section,

(5) FIG. 4 shows the spindle drive according to FIG. 1 with a detailed view of the outer housing of the spindle drive housing,

(6) FIG. 5 shows the spindle drive according to FIG. 1 in a fully expanded state, and

(7) FIG. 6 shows the spindle drive according to FIG. 1.

DETAILED DESCRIPTION

(8) Referring to FIGS. 1-4, the spindle drive represented in the drawings serves the purpose of motoric adjustment of an adjustment element 1, configured as a tailgate, of a motor vehicle. Other fields of application of the spindle drive according to the proposal are conceivable, as is explained in detail further below.

(9) The spindle drive is equipped in a conventional manner with a drive unit 2 and a spindle-spindle nut transmission 3 arranged downstream of drive unit 2 in terms of drive for generating linear drive movements. In this case, drive unit 2 has an optionally tubular and one-piece drive unit housing 4 and therein a drive motor 5 and an intermediate transmission 6 arranged downstream of drive motor 5 in terms of drive. Depending on the configuration of drive motor 5, an intermediate transmission 6 can also be omitted.

(10) A particular lean configuration is produced in that drive unit 2 and spindle-spindle nut transmission 3 are arranged behind one another on geometrical spindle axis 7. Here, a tubular spindle drive housing 8 is correspondingly provided with a tubular inner housing 8a and a tubular outer housing 8b, wherein inner housing 8a runs in a telescope-like manner in outer housing 8b. A combined view of FIGS. 2 and 3 shows that inner housing 8a here is pushed into outer housing 8b.

(11) FIG. 3 shows that outer housing 8b of spindle drive housing 8 accommodates drive unit 2 with drive unit housing 4 and is connected to drive unit 2. Drive unit 2 has for this purpose an axial connecting portion 2a which is connected to outer housing 8b in a non-positive locking, positive locking or materially engaged manner. In one configuration, the connection between outer housing 8b and drive unit 2 involves a latching connection, with hook-shaped latching elements 9a, which engage in counterlatching elements 9b represented in FIG. 4, here and preferably on drive unit 2.

(12) It should be pointed out that the connection between outer housing 8b and drive unit 2 does not have to be a direct connection. On the contrary, it is conceivable that outer housing 8b is connected to an element which is in turn connected to drive unit 2.

(13) It should furthermore be pointed out at this point that the terms axial and radial always relate to geometrical spindle axis 7 of spindle-spindle nut transmission 3. Corresponding express indications are omitted below for the purpose of clarity.

(14) The axial extension of drive unit housing 4 is in some cases at least the axial extension of drive motor 5, in this case together with intermediate transmission 6. It can in principle also be the case that drive unit housing 4 is configured to be slightly longer. However, it can be the case that the axial extension of drive unit housing 4 is smaller than 150% of the axial extension of drive motor 5, in this case shown together with intermediate transmission 6. Drive unit 2 is thus to a certain extent configured as a drive cartridge which can be configured separately from spindle drive housing 8.

(15) FIG. 3 shows that outer housing 8b fully overlaps with drive unit 2 along geometrical spindle axis 7. A visually attractive configuration of outer housing 8b can thus be easily produced. Moreover, connecting portion 2a can be lengthened depending on the application so that a particularly stable connection can be realized between drive unit housing 4 and outer housing 8b.

(16) As one targeted configuration of the spindle drive, the outer housing 8b is primarily composed of a first material and the drive unit housing 4 is primarily composed of a second material which is different from the first material. In this case the second material is harder than the first material, and/or the second material is less flexible than the first material and/or the second material has a higher toughness than the first material.

(17) It can alternatively or additionally be provided that the first material is a plastic material and that the second material is a metallic material. In this case the metallic material is steel. In summary, a solution according to the proposal enables a configuration of drive unit housing 4 and outer housing 8b tailored to the actual force conditions.

(18) In the depicted case, inner housing 8a and/or outer housing 8b always lie outside the flow of force of the drive force. This primarily means that no axial forces which go back to drive unit 2 are conducted via inner housing 8a and/or outer housing 8b. It can additionally also be provided that no torques are conducted around geometrical spindle axis 7 to inner housing 8a and/or outer housing 8b, as is explained further below.

(19) FIG. 3 shows the fully retracted state of the spindle drive in which inner housing 8a overlaps with an axial overlapping portion 2b of drive unit 2. In the fully extended state, inner housing 8a may not overlap with drive unit 2. It is in principle also conceivable that a certain degree of overlap always remains.

(20) The above overlap between inner housing 8a and drive unit 2 is possible due to the fact that an annular gap is provided between drive unit housing 4 and inner housing 8a, into which gap inner housing 8a dips. For this purpose, drive unit housing 4 has, in the region of overlapping portion 2b, a reduced diameter relative to the rest of the drive unit housing. In this example, the intermediate transmission 6 is accommodated in overlapping portion 2b.

(21) A combined view of FIGS. 2 and 3 shows that drive unit housing 4 is, as discussed above, configured to be substantially tubular, wherein the diameter of drive unit housing 4 in overlapping portion 2b is slightly smaller than in connecting portion 2a which has still to be explained.

(22) Two connections 10, 11, which are arranged on geometrical spindle axis 7, are provided for transfer of the linear drive movements in the case of the represented embodiment. In a further configuration, a first connection 10 is connected to drive unit 2, while second connection 11 is connected via a guide tube 12 to spindle nut 3a of spindle-spindle nut transmission 3. Spindle nut 3a cogs in a manner known per se with spindle 3b of spindle-spindle nut transmission 3, which spindle 3b can be driven rotatably on drive unit 2, but axially fixedly mounted and by means of drive motor 5 via intermediate transmission 6. No axial drive forces are conducted via spindle drive housing 8 as a result of this structural design.

(23) The fact is also interesting in the case of the represented embodiment that a torque tube 13 which is fixed on the drive unit is provided and is optionally fastened on drive unit housing 4. A positive lock can thus be provided between spindle nut 3a or guide tube 12 and torque tube 13 such that an anti-twist lock is produced between the two connections 10, 11. As a result, it is ensured that no torques are also conducted around geometrical spindle axis 7 to spindle drive housing 8.

(24) In principle, however, the anti-twist lock between the two connections 10, 11 can also be provided by a positive lock between inner housing 8a and outer housing 8b. Spindle drive housing 8 must then be configured so that it can absorb corresponding torques around geometrical spindle axis 7.

(25) The realization of the engagement between drive unit housing 4 and outer housing 8b has particular importance for the drainage of spindle drive housing 8. In principle, it cannot namely be avoided that condensation water or the like occurs in spindle drive housing 8 which must escape in some way. It is provided for this purpose that axial connecting portion 2a of drive unit housing 4 is in engagement with outer housing 8b via a spacer arrangement 14. Spacer arrangement 14 generates in this case a radial drainage gap 15 between connecting portion 2a and outer housing 8b.

(26) In this example, spacer arrangement 14 is formed from at least one web 16 which furthermore preferably runs substantially axially. Web 16 is, as represented in FIG. 4, preferably arranged on connecting portion 2a of drive unit housing 4. In principle, the at least one web 16 can also, however, be arranged on drive unit housing 4. Due to the fact that the at least one web 16 bears against drive unit housing 4, the width of drainage gap 15 corresponds precisely to the height of the at least one web 16.

(27) A combined view of FIGS. 2 and 3 shows that inner housing 8a has, on its end portion distant from the drive unit, a covering cap 17 which, in the fully retracted state represented in FIG. 3, is in sealing engagement with the end portion, which is distant from the drive unit, of outer housing 8b and, in the extended state, is not in engagement with the end portion, which is distant from the drive unit, of outer housing 8b. In the case of the represented embodiment, covering cap 17 has a circumferential collar 18 which exhibits a certain degree of axial extension. In the case of adjustment of the spindle drive into the fully retracted state, collar 18 is pushed over outer housing 8b so that a certain degree of overlap 19 is generated between collar 18 and outer housing 8b.

(28) Covering cap 17 has a certain degree of elasticity at least in the region in which sealing engagement with outer housing 8b takes place. Covering plate 17 is preferably formed from a rubber-like material in any event in this region.

(29) Covering cap 17 is furthermore in sealing engagement with connection 11, wherein the relevant portion of covering cap 17 is configured in the manner of a rubber sleeve.

(30) A spindle drive with an above covering cap 17, which comes into sealing engagement with outer housing 8b, is the subject matter of a further teaching which has independent significance. According to this further teaching, the essential issue is not the implementation of a drive unit housing 4 in the above sense. Reference can otherwise be made to all the statements above.

(31) A spindle drive with a covering cap 17 described above can above all be used if covering cap 17, in the case of a fully retracted spindle drive, is located in the upper region of the spindle drive so that it must be prevented that fluid runs from above into the region between inner tube 8a and outer tube 8b.

(32) In so far as the end portion, which is distant from the drive unit, of inner housing 8a lies, however, at the bottom in the case of a fully retracted spindle drive, it must be ensured that moisture present in spindle drive housing 8 can reach the outside. It is preferably provided for this that a covering cap, not represented here, provides at least one drainage recess for drainage of inner housing 8a.

(33) Reference should also be made to the fact that the spindle drives according to the proposal can be applied to all types of adjustment elements of a motor vehicle. These include a tailgate discussed above, a trunk lid, an engine hood, a side door, a trunk lid, an elevating roof or the like of a motor vehicle.

(34) According to a further teaching which also has independent significance, a flap arrangement for a motor vehicle with a flap 1 is claimed which is equipped with at least one described spindle drive for motoric adjustment of flap 1.

(35) In principle, the at least one spindle drive of the flap arrangement can be arranged laterally of a flap opening, preferably in a drip rail. It is, however, also conceivable that the spindle drive is arranged transverse to the longitudinal axis of the motor vehicle, in particular in the region of the rear roof frame and acts via deflection elements on the flap or on the body of the motor vehicle.

(36) In another configuration, inner housing 8a is equipped on its end portion distant from the drive unit with a covering cap 17 which, in the case of a fully retracted spindle drive and closed flap 1, lies in the upper region of the spindle drive. It is then preferably the case that covering cap 17 as explained above is in sealing engagement with the end portion, which is distant from the drive unit, of outer housing 8b.

(37) If, however, the covering cap arranged at the end portion, which is distant from the drive unit, of inner housing 8a lies in the lower region of the spindle drive in the case of a fully retracted spindle drive and closed flap 1, it is proposed that the covering cap provides at least one drainage recess for drainage of inner housing 8b, as has also been explained.

(38) In order to explain the flap arrangement according to the proposal in its full scope, reference is otherwise made to the explanations with regard to the spindle drives according to the proposal.

(39) FIG. 5 shows the spindle drive in a fully expanded state. FIG. 5 shows the tubular inner housing 8a not overlapping with the drive unit 2 in the fully extended state. FIG. 6 shows the spindle drive with the covering cap 17 having at least one drainage recess 20 for drainage of the inner housing 8a. FIG. 6 further shows the covering cap 17 lying in a lower region of the spindle drive.