Spindle drive

Abstract

A spindle drive for a closure element of a vehicle for generating drive movements along a geometric spindle axis, having a tube-like drive housing and a spindle unit with a spindle guide bush and a spindle movably mounted therein are provided, a first drive connection and a second drive connection which is linearly displaceable with respect to the latter being provided to generate the drive movements, a spindle guide tube being connected to the first drive connection and, together with the first drive connection, forming a first drivetrain component which is connected to the spindle guide bush of the spindle unit, and a connecting element being connected to the second drive connection and forming a second drivetrain component which is connected to the spindle. The spindle can be mounted in the spindle guide bush in such a way that it is purely linearly movable in the spindle guide bush.

Claims

1. A spindle drive for moving a closure element of a motor vehicle, comprising: a tubular drive housing, a spindle, and, in the tubular drive housing along a geometric spindle axis of the spindle, a spindle unit with a spindle guide bush and the spindle movably guided in the spindle guide bush, a first drive connection and a second drive connection which is linearly displaceable with respect to the first drive connection so as to allow linear drive movements relative to each other along the spindle axis, a spindle guide tube being connected to the first drive connection and, together with the first drive connection, forming a first drivetrain component which is connected to the spindle guide bush of the spindle unit, and a connecting element being connected to the second drive connection and forming, together with the second drive connection, a second drivetrain component which is connected to the spindle, wherein the spindle is mounted in the spindle guide bush in such a way that the spindle is exclusively linearly movable in the spindle guide bush, wherein the spindle drive further comprises a tubular spring guide in the tubular drive housing, the tubular spring guide extends along the spindle axis, wherein the tubular spring guide radially surrounds the spindle guide tube and the spindle, wherein an outer spring, which forms a drive element of the spindle drive and which exerts an axial spring load on the first drive connection and the second drive connection, is mounted along the spindle axis, at least with certain portions of the outer spring circumferentially on the tubular spring guide, wherein the tubular spring guide and the spindle guide tube are connected to the first drive connection, wherein the tubular spring guide is disposed within the outer spring.

2. The spindle drive as claimed in claim 1, wherein at least one of the spindle guide bush and the spindle is completely threadless.

3. The spindle drive as claimed in claim 1, wherein the spindle has a guide element on a spindle portion, wherein the guide element is arranged within the spindle guide tube between the first drive connection and the spindle guide bush, wherein the guide element supports the spindle on the inner side of the spindle guide tube.

4. The spindle drive as claimed in claim 3, wherein the guide element is configured such that the guide element allows a pressure equalization between a portion of the spindle guide tube situated axially on one side of the guide element and a portion of the spindle guide tube situated axially on an opposite side of the guide element.

5. The spindle drive as claimed in claim 3, wherein the guide element is configured such that the guide element prevents a pressure equalization between a portion of the spindle guide tube situated axially on one side of the guide element and a portion of the spindle guide tube situated axially on an opposite side of the guide element.

6. The spindle drive as claimed in claim 1, wherein the spindle guide bush is configured in such a way that the spindle guide bush allows a pressure equalization between an interior of the spindle guide tube and a surrounding of the spindle guide tube.

7. The spindle drive as claimed in claim 1, wherein an inner spring which forms a damping element of the spindle drive and which damps a linear movement of the spindle is mounted within the spindle guide tube along the spindle axis.

8. The spindle drive as claimed in claim 1, wherein a spacer bush is provided along the spindle axis and occupies a space.

9. The spindle drive as claimed in claim 8, wherein the space occupied by the spacer bush extends axially in a region between the first drive connection and the tubular spring guide or in a region between the first drive connection and the outer spring, and wherein the outer spring bears axially against the spacer bush.

10. The spindle drive as claimed in claim 1, wherein a braking device is provided which is configured to bring about braking of a relative movement between the spindle and the spindle guide bush in addition to a necessarily occurring friction between the spindle and the spindle guide bush.

11. The spindle drive as claimed in claim 10, wherein the braking device is configured to exert a frictional force on the spindle.

12. The spindle drive as claimed in claim 1, wherein the outer spring is arranged in a radial interspace between the tubular spring guide and the tubular drive housing.

13. The spindle drive as claimed in claim 1, wherein the spindle guide bush is configured in such a way that the spindle guide bush prevents a pressure equalization between an interior of the spindle guide tube and a surrounding of the spindle guide tube.

14. A drive arrangement for moving a closure element of a motor vehicle having at least a first spindle drive and a second spindle drive, wherein the first spindle drive comprises a tubular drive housing, a spindle, and, in the tubular drive housing along a geometric spindle axis of the spindle, a spindle unit with a spindle guide bush and the spindle movably guided in the spindle guide bush, a first drive connection and a second drive connection which is linearly displaceable with respect to the first drive connection so as to allow linear drive movements relative to each other along the spindle axis, a spindle guide tube being connected to the first drive connection and, together with the first drive connection, forming a first drivetrain component which is connected to the spindle guide bush of the spindle unit, and a connecting element being connected to the second drive connection and forming, together with the second drive connection, a second drivetrain component which is connected to the spindle, wherein the spindle is mounted in the spindle guide bush in such a way that the spindle is exclusively linearly movable in the spindle guide bush, wherein the first spindle drive further comprises a tubular spring guide in the tubular drive housing, the tubular spring guide extends along the spindle axis, wherein the tubular spring guide radially surrounds the spindle guide tube and the spindle, wherein an outer spring, which forms a drive element of the first spindle drive and which exerts an axial spring load on the first drive connection and the second drive connection, is mounted along the spindle axis, at least with certain portions of the outer spring circumferentially on the tubular spring guide, wherein the tubular spring guide and the spindle guide tube are connected to the first drive connection, wherein the tubular spring guide is disposed within the outer spring, wherein the second spindle drive comprises: a tubular drive housing, a spindle, and, in the tubular drive housing of the second spindle drive along a geometric spindle axis of the spindle of the second spindle drive, a spindle unit with a spindle guide bush and the spindle of the second spindle drive which is movably guided in the spindle guide bush of the second spindle drive, wherein the second spindle drive comprises a first drive connection and a second drive connection which is linearly displaceable with respect to the first drive connection of the second spindle drive for allowing linear drive movements relative to each other along the spindle axis of the second spindle drive, wherein the second spindle drive comprises a spindle guide tube being connected to the first drive connection of the second spindle drive and forming, together with the first drive connection of the second spindle drive, a first drivetrain component which is connected to the spindle guide bush of the second spindle drive, and wherein the second spindle drive comprises a connecting element being connected to the second drive connection of the second spindle drive and forming, together with the second drive connection of the second spindle drive, a second drivetrain component which is connected to the spindle of the second spindle drive, wherein the first spindle drive has no drive unit with a drive motor.

15. The drive arrangement as claimed in claim 14, wherein the second spindle drive comprises a drive unit with a drive motor for driving the spindle of the second spindle drive.

16. The drive arrangement as claimed in claim 15, wherein the spindle of the second spindle drive includes a spindle external thread and the spindle guide bush of the second spindle drive includes a spindle nut internal thread, wherein the spindle external thread and the spindle nut internal thread form a screw engagement with one another.

17. The drive arrangement as claimed in claim 16, wherein the connecting element of the second spindle drive transmits a rotational movement generated by the drive motor to the spindle of the second spindle drive.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The disclosure will be explained in more detail below with reference to a drawing illustrating only one exemplary embodiment. In the drawing,

(2) FIG. 1 shows, in a highly schematic illustration, the rear region of a motor vehicle having a proposed drive arrangement which has a proposed manual spindle drive and a proposed motor-operator spindle drive,

(3) FIG. 2 shows, in a detail view, a first embodiment of a proposed spindle drive for a passive side in the extended state,

(4) FIG. 3a shows enlarged details of the spindle drive from FIG. 2,

(5) FIG. 3b shows enlarged details of the spindle drive from FIG. 2,

(6) FIG. 3c shows enlarged details of the spindle drive from FIG. 2,

(7) FIG. 4 shows, in a detail view, a second embodiment of a proposed spindle drive for the passive side in the retracted state,

(8) FIG. 5a shows enlarged details of the spindle drive from FIG. 4,

(9) FIG. 5b shows enlarged details of the spindle drive from FIG. 4, and

(10) FIG. 5c shows enlarged details of the spindle drive from FIG. 4.

DETAILED DESCRIPTION

(11) The spindle drives 1, 1 illustrated in the drawing serve for adjusting a closure element 2 of a motor vehicle, with, by way of example, the spindle drive 1 illustrated on the left in FIG. 1 being a manual spindle drive, that is to say a non-motor-operated spindle drive, and in this respect forming the passive side of the drive arrangement illustrated in FIG. 1 for a closure element 2, whereas the spindle drive 1 illustrated on the right in FIG. 1 is a motor-operated spindle drive and in this respect forms the active side of the drive arrangement. As regards the further understanding of the term closure element, reference may be made to the introductory part of the description. In the text which follows, the disclosure will be explained on the basis of a closure element 2 designed as a tailgate.

(12) The drive-side spindle drive 1 is equipped with a drive unit which is here electric and which has an electric drive motor 27 and an intermediate gear mechanism connected downstream of the drive motor. Connected downstream of the drive unit overall in terms of drive is a spindle unit 3 which is designed as a spindle/spindle nut mechanism. The spindle unit 3 comprises a spindle guide bush 4 configured as a spindle nut and a spindle 5 mounted movably therein for the purpose of generating linear drive movements between two drive connections 6, 7 along a geometric spindle axis 8. The drive connections 6, 7 are configured as ball sockets which are in engagement with corresponding vehicle-side ball heads. Spindle guide bush 4 and spindle 5 are here mounted in screw engagement with one another and in such a way that a rotational movement transmitted by the drive unit to the spindle 5 brings about a linear movement of the spindle guide bush 4 along the geometric spindle axis 8 relative to the spindle 5, which in turn causes the closure element 2, here the tailgate, to be adjusted between the open position illustrated in FIG. 1 and a closed position or intermediate positions, which is/are not illustrated.

(13) The further spindle drive 1 is configured as a manual spindle drive and, in various embodiments does not have a drive motor. A further difference between the spindle drives 1 and 1 is that the manual spindle drive 1 has a spindle unit 3 with a spindle guide bush 4 and a spindle 5 mounted movably therein, which are mounted relative to one another in such a way that the spindle 5 can be moved purely linearly in the spindle guide bush 4, that is to say a displacement of the spindle 5 relative to the spindle guide bush 4 is possible without relative rotational movement between the two components 4, 5. For this purpose, the spindle guide bush 4 of the spindle unit 1 has no internal thread. Additionally or alternately, the spindle 5 is also threadless.

(14) What is key then is that, as a result of the otherwise substantially identical design, such as an exactly identical design, of the spindle drives 1, 1, there is no need to provide a separate construction, especially a gas pressure damper or a gas pressure spring, for the passive side; rather, recourse can be had in the construction of the manual spindle drive 1 to the components already present per se through the motor-operated spindle drive 1. This considerably simplifies the design of a drive arrangement having a manual and a motor-operated spindle drive 1, 1.

(15) Since, in the proposed solution, gas pressure dampers or gas pressure springs are dispensed with, but use is made for the passive side of an easily converted spindle drive which is customarily used on the active side, it is also possible for a power loss over the service life on the passive side to be minimized. There is also no appreciably increase in the friction, as in gas pressure dampers or the like, in the course of the service life. Finally, the proposed solution also produces an acoustic optimization.

(16) In the text which follows, the design of the proposed manual spindle drive 1 will be described in more detail on the basis of the embodiments in FIGS. 2 and 3 on the one hand and FIGS. 4 and 5 on the other hand.

(17) In principle, according to both embodiments, the spindle drive 1 has, as already explained, a spindle unit 3 with a spindle guide bush 4 and a spindle 5 mounted movably therein, the spindle 5 being mounted in the spindle guide bush 4 so as to be purely linearly movable. The spindle unit 3 is surrounded in the radial direction by a tubular drive housing 9 which is in two parts here, a first housing portion 9a, also referred to as an outer tube, being linearly guided on a second housing portion 9b, also referred to as inner tube.

(18) Furthermore, a spindle guide tube 10 is connected to the first drive connection 6 within the drive housing 9 and forms, together with the first drive connection 6, a first drivetrain component 11 which is connected to the spindle guide bush 4. A second drivetrain component 12 is formed by a connecting element 13 and the second drive connection 7 which is connected to the connecting element 13. The second drivetrain component is in turn connected to the spindle 5.

(19) If then the spindle drive 1 is manually actuated by the two drive connections 6, 7 being displaced relative to one another, the spindle guide bush 4 is correspondingly moved concomitantly relative to the spindle 5.

(20) As can be seen particularly in FIG. 3b, the spindle 5 has a guide element 16 on a spindle portion 14, in particular on the free end 15 of the spindle 5, which is arranged within the spindle guide tube 10 between the first drive connection 6 and the spindle guide bush 4, which guide element supports the spindle 5 on the spindle guide tube 10 on the inner side. The guide element 16 is configured here in such a way that it allows a pressure equalization between the portion of the spindle guide tube 10 situated axially upstream of the guide element 16 and the portion of the spindle guide tubed 10 situated axially downstream of the guide element 16. In principle, however, it is also conceivable, according to a variant, that the guide element 16 bears in a sealing manner against the spindle 5 and the spindle guide tube 10 and in this respect prevents a pressure equalization and thus assumes a damping function.

(21) The spindle guide bush 4 in turn is here configured in such a way that it allows a pressure equalization between the interior of the spindle guide tube 10 and the surroundings of the spindle guide tube 10. It is possible, here too, according to a further variant, for the spindle guide bush 4 to be configured in such a way that it prevents a pressure equalization and thus likewise ensures a damping function.

(22) In the embodiments shown in FIGS. 2 to 5, a tubular spring guide 17 is also provided in the drive housing 9 along the spindle axis 8 and radially surrounds the spindle guide tube 10 and here also the spindle 5. An axial portion of an outer spring 18 is mounted circumferentially on the tubular spring guide 17, which spring forms a drive element 19 of the spindle drive 1 and axially preloads the first drive connection 6 with respect to the second drive connection 7. The outer spring 18 is a pressure spring 18 here. The outer spring 18 is arranged in a radially peripheral interspace 20 between the tubular spring guide 17 and the drive housing 9.

(23) Also provided is a second, inner spring 21, which is also a pressure spring 21, which forms a damping element 22 of the spindle drive 1 and damps the linear movement of the spindle 5 in its end position or before reaching its end position. This inner spring 21 is mounted radially within the spindle guide tube 10.

(24) The two embodiments in FIGS. 2 and 3 on the one hand and 4 and 5 on the other hand differ substantially only in terms of the spacer bush 23, 23 described in more detail below, which spacer bush in the one case forms (FIG. 3a) an annular space 24, which is here air-filled, and in the other case occupies (FIG. 5a), i.e. completely fills, an annular space 24. The respective annular space 24, 24 extends axially in a region between the second drive connection 7 and the tubular spring guide 17 and the outer spring 18, the outer spring 18 here bearing axially against the respective spacer bush 23, 23. The spacer bush 23, 23 makes it possible to compensate for or fill the insulation space which, in the case of a motor-operated spindle drive 1, would be filled by a drive motor and possibly an intermediate gear mechanism. In this way, the remaining components of the spindle drive 1, which are also provided in the spindle drive 1, do not need to be modified, but can be structurally identical. This applies in particular to one or more of the following components: drive housing 9, tubular spring guide 17, outer spring 18, inner spring 21 and spindle guide tube 10. In principle, it is also conceivable for the spindle guide bush 4 or the spindle 5 to likewise be designed in a structurally identical manner in relation to the other spindle drive 1 as long as it is ensured that the spindle 5 is also purely linearly movable in the spindle guide bush 4.

(25) In the embodiment in FIGS. 4 and 5, the spacer bush 23, the housing portion 9a of the drive housing 9 and the tubular spring guide 17 are designed together in one piece (integrally), thus forming here a one-piece component 25 in the form of a spring-receiving tube. In this case, too, the remaining components of spindle drive 1 and spindle drive 1 can be structurally identical, which applies particularly to the outer spring 18, the inner spring 21 and/or the spindle guide tube 10. In principle, it is also conceivable here that the spindle guide bush 4 or the spindle 5 is additionally also structurally identical in relation to the other spindle drive 1 as long as a purely linear relative movement between spindle guide bush 4 and spindle 5 is ensured.

(26) Furthermore, a separate braking device 26 can be provided in the manual spindle drive 1 according to FIGS. 2 to 5, which braking device brings about braking of a linear relative movement between spindle drive bush 4 and spindle 5, the braking can be a continuous braking. This is achieved in particular by a frictional force being exerted on the spindle 5 by friction-braking elements, which are not illustrated here for the sake of clarity.

(27) Finally, there should also be described an embodiment of the motor-operated spindle drive 1 as can be provided on the left side of the motor vehicle illustrated in FIG. 1. In a similar manner to the manual spindle drive 1, the spindle drive 1 comprises a tube-like drive housing 9 and, in the drive housing 9 along the spindle axis 8, a spindle unit 3 with a spindle guide bush 4 and a spindle 5 movably mounted therein, a first drive connection 6 and a second drive connection 7 which is linearly displaceable with respect thereto being provided to generate the drive movements, a spindle guide tube 10 being connected to the first drive connection 6 and forming, together with the first drive connection 6, a first drivetrain component 11 which is connected to the spindle guide bush 4 of the spindle unit 3, and a connecting element 13 being connected to the second drive connection 7 and forming, together with the second drive connection 7, a second drivetrain component 12 which is connected to the spindle 5 of the spindle unit 3.

(28) Here, however, by contrast with the manual spindle drive 1, and as has been stated, a drive unit with a drive motor is provided which is connected downstream of the spindle unit 3 in terms of drive. In addition, the spindle unit 3 is designed as a spindle/spindle nut mechanism which has the spindle 5 and the spindle guide bush 4 as mechanism partners, the spindle 5 being a spindle with a spindle external thread and the spindle guide bush 4 being a spindle nut with a spindle nut internal thread, which form a screw engagement with one another. The connecting element 13, which can be a constituent part of the drive motor or of an intermediate gear mechanism of the drive unit, here transmits a rotational movement generated by the drive motor to the spindle 5.

(29) It is optionally possible, as also in the manual spindle drive 1, for a spacer bush 23, 23 to be provided along the spindle axis 8, which spacer bush forms a one-piece component 25 together with a housing portion 9a of the drive housing 9 and/or a tubular spring guide 17 which radially surrounds the spindle guide tube 10 and/or the spindle 5.