SPINDLE DRIVE

Abstract

A spindle drive includes a spindle nut, wherein the spindle nut is rotatably supported in a housing, a spindle, wherein the spindle is configured to be displaced in relation to the housing, an axial rolling bearing configured to support the spindle nut, wherein the axial rolling bearing does not guide axially, and a sliding bearing configured to support the spindle and act in a radial direction.

Claims

1. A spindle drive comprising: a spindle nut configured to be rotated in a housing; and a spindle that interacts with the spindle nut, wherein the spindle nut is supported in the housing by two axial roller bearings and the spindle is supported in the housing by two radial sliding bearings.

2. The spindle drive of claim 1, wherein rolling elements in the axial roller bearings roll on one side along the spindle nut and on the other side along bearing disks placed in the housing.

3. The spindle drive of claim 2, wherein the bearing disks are secured radially in the housing by steps formed therein.

4. The spindle drive of claim 1, wherein the axial roller bearings are roller bearings or needle bearings.

5. The spindle drive of claim 1, wherein at least one radial sliding bearing is formed directly between the spindle and the housing.

6. The spindle drive of claim 1, wherein at least one radial sliding bearing is formed between a sliding bearing element connected to the spindle and the housing.

7. The spindle drive of claim 1, wherein rolling elements are provided between the spindle and the spindle nut and provided solely for radial support of the spindle nut on the spindle.

8. The spindle drive of claim 1, wherein the spindle nut is designed as a pulley.

9. The spindle drive of claim 1, wherein the spindle nut is an output drive gear.

10. (canceled)

11. A spindle drive, comprising: a spindle nut rotatably supported in a housing; a spindle is configured to be displaced in relation to the housing; an axial rolling bearing configured to support the spindle nut, wherein the axial rolling bearing does not guide axially; and a sliding bearing configured to support the spindle and act in a radial direction.

12. The spindle drive of claim 11, wherein the spindle drive is configured as a ball screw drive that includes a plurality of rolling elements configured to roll between the spindle and the spindle nut.

13. The spindle drive of claim 11, wherein radial forces acting on the spindle nut are applied to the plurality of rolling elements and convert rotation of the spindle nut into the displacement of the spindle.

14. The spindle drive of claim 11, wherein the sliding bearing includes a sliding bearing element.

15. The spindle drive of claim 11, wherein the axial rolling bearing includes a bearing disk and a plurality of rollers.

16. The spindle drive of claim 15, wherein the bearing disk is located on an annular disk section of the housing.

17. The spindle drive of claim 16, wherein the bearing disk is secured radially by a cylindrical step of the housing.

18. The spindle drive of claim 17, wherein the annular disk section and the cylindrical step are an extension of the housing.

19. The spindle drive of claim 18, wherein the extension extends asymmetrically in a radial direction via cylindrical tube sections of the housing, wherein the cylindrical tube sections are located axially in front or behind the spindle nut.

20. A spindle drive, comprising: a spindle nut, wherein the spindle nut is rotatably supported in a housing; a spindle, wherein the spindle is configured to be displaced in relation to the housing; a plurality of axial rolling bearings configured to support the spindle nut, wherein the axial rolling bearing does not guide axially; and a plurality of sliding bearings configured to support the spindle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Two exemplary embodiments of the disclosure shall be explained in greater detail below on the basis of the drawings. Therein:

[0016] FIG. 1 shows a spindle drive in a sectional view,

[0017] FIG. 2 shows a detail of an alternative design for a spindle drive.

DETAILED DESCRIPTION

[0018] The following explanations relate to both exemplary embodiments unless otherwise specified.

[0019] A spindle drive, indicated as a whole by the reference numeral 1, is used to adjust the height of a motor vehicle. Reference is made to the prior art cited in the introduction regarding the principle function of the spindle drive 1.

[0020] The spindle drive 1 is configured as a ball screw drive, wherein rolling elements 4, specifically balls, roll between a spindle 2 and a dedicated spindle nut 3. A ball return is not shown in the figures. The spindle 2 has a ball groove 5, describing a single threading. In this manner, rotation of the spindle nut 3 is converted to a linear displacement of the spindle along the central axis M. A twisting safeguard for the spindle 2 in a housing 6 is not shown.

[0021] There are two sliding bearings 7, 9, i.e. radial sliding bearings, for the radial bearing of the spindle 2 in the housing 6, which each have a sliding bearing element 8, 10 in the embodiment shown in FIG. 1. The embodiment shown in FIG. 2 differs therefrom in that it does not have the sliding bearing element 10 in the embodiment in FIG. 1. The embodiment according to FIG. 2 is thus a simplified variation of the spindle drive 1, in which there is also a double sliding bearing of the spindle 2 in the housing 6. In another, further simplified embodiment, not shown herein, the sliding element 8 located at the top in FIG. 1 can also be omitted, both in the embodiment according to FIG. 2 as well as in the embodiment according to FIG. 1. The hollow spindle 2 has an inner tube 11 in all of the embodiments.

[0022] In contrast to the spindle 2, which is only supported radially in the housing 6, the spindle nut 3 is only supported in both axial directions in relation to the housing 6. There are two axial bearings 12, 13 for this, specifically axially roller bearings, each of which has a bearing disk 14, 15 and numerous rollers 16, 17 serving as rolling elements. Each bearing disk 14, 15 is placed on an annular disk section 18, 19 of the housing 6. Each bearing disk 14, 15 is secured radially by a cylindrical step 24, 25 of the housing in the present case. The annular disk sections 18, 19 and the cylindrical steps 24, 25 are structures of an extension of the housing 6 indicated as a whole with the numeral 20.

[0023] The housing extension 20 extends asymmetrically in the radial direction via cylindrical tube sections 21, 22 of the housing 6, which are located axially in front of or behind the spindle nut 3. As a result, an extension space 23 is created inside the housing extension 20, which can accommodate a pulley, not shown. A drive belt wraps around this pulley and the spindle nut 3, by means of which the spindle nut 3 can be driven using a belt drive.

[0024] Radial forces acting on the spindle nut 3 are applied to the rolling elements 4, which support the spindle nut 3 on the spindle 2, and also convert the rotation of the spindle nut 3 into the displacement of the spindle 2. The spindle nut 3 is supported in a floating manner in the housing 6 of the spindle drive 1 by the axial roller bearings 12, 13. Radial forces acting on the spindle nut 3 have no effect on the force acting within the axial roller bearings 12, 13, in contrast to bearing assemblies that have angular-contact bearings.

LIST OF REFERENCE SYMBOLS

[0025] 1 spindle drive [0026] 2 spindle [0027] 3 spindle nut [0028] 4 rolling element, ball [0029] 5 ball groove [0030] 6 housing [0031] 7 radial sliding bearing [0032] 8 sliding bearing element [0033] 9 radial sliding bearing [0034] 10 sliding bearing element [0035] 11 inner tube [0036] 12 axial roller bearing [0037] 13 axial roller bearing [0038] 14 bearing disk [0039] 15 bearing disk [0040] 16 rolling element, roller [0041] 17 rolling element, roller [0042] 18 annular disk section [0043] 19 annular disk section [0044] 20 housing extension [0045] 21 tube section [0046] 22 tube section [0047] 23 extension space [0048] 24 step [0049] 25 step [0050] M central axis