Pivotable spindle nut

Abstract

The invention relates to a spindle drive, comprising a drive unit, a spindle, and a spindle nut in threaded engagement with the spindle, the spindle nut being driven by the drive unit by means of a drive element, and wherein the spindle nut is mounted on the drive element in such a way that the spindle nut and the spindle in threaded engagement with it are pivotable relative to the drive element.

Claims

1. A spindle drive, comprising: a drive unit, a spindle having a longitudinal axis, and a spindle nut in threaded engagement with the spindle, wherein the spindle nut is driven by the drive unit by means of a drive element, and wherein the spindle nut is mounted on the drive element so that the spindle nut and the spindle in threaded engagement with the spindle nut are pivotable relative to the drive element, wherein the drive element comprises a base element and a cover element, wherein the base element accommodates two followers in which a cage element is pivotably mounted around a first axis, in which the spindle nut is pivotably mounted around a second axis which is perpendicular to the first axis, wherein the cover element positions the followers rigidly in the base element, and wherein the first axis and the second axis are different from the longitudinal axis of the spindle.

2. A spindle drive according to claim 1, wherein the spindle nut is gimballed to the drive element.

3. A spindle drive according to claim 1, wherein the drive element has toothing on an outer circumference which are in engagement with a gear wheel driven by the drive unit.

4. A spindle drive according to claim 3, wherein the longitudinal axis of the spindle, in a position that is parallel to an axis of rotation of the drive element, is oriented substantially parallel to the longitudinal axis of a driven shaft of the drive unit.

5. A spindle drive according to claim 1, wherein the drive element is connected to a worm wheel which engages with a worm driven by the drive unit.

6. A spindle drive according to claim 5, wherein the longitudinal axis of the spindle, in a position that is parallel to an axis of rotation of the drive element, is oriented substantially perpendicular to the longitudinal axis of a driven shaft of the drive unit.

7. A spindle drive according to claim 6, wherein the longitudinal axis of the spindle is coaxial to the axis of rotation of the drive element.

8. A spindle drive according to claim 5, wherein the drive element and the worm wheel are integrally formed.

9. A spindle drive according to claim 1, wherein the drive element has at least one conical opening which widens from the spindle nut to the outside of the drive element and through which the spindle passes.

10. A spindle drive according to claim 1, wherein the spindle nut is substantially spherical.

11. A spindle chive according to claim 1, wherein a gear mechanism is arranged between the drive element and the drive unit.

12. A spindle drive according to claim 11, wherein the gear mechanism is a planetary gear.

13. A spindle drive according to claim 1, wherein a bike is arranged between the drive element- and the drive unit.

14. A spindle drive according to claim 13, wherein the brake is arranged adjacently to the drive unit.

15. A spindle drive according to claim 13, wherein the brake is a friction brake.

16. A spindle drive according to claim 1, wherein the first axis is a pivot axis, wherein the cage element comprises a plurality of projections that define the pivot axis, and wherein a follower of the two followers is arranged on the plurality of projections.

17. A spindle drive according to claim 1, wherein each of the two followers is arranged in a corresponding recess of the base element, and wherein the cover element clamps the two followers between the cover element and the base element.

Description

(1) Below, the invention will be described in more detail with the help of two embodiments and with reference to the accompanying drawings, in which

(2) FIG. 1 shows a side cross-sectional view of a first embodiment of the spindle drive according to the invention,

(3) FIG. 2 shows a view of a three-quarter section of a second embodiment of the spindle drive according to the invention.

(4) In FIG. 1, a spindle drive according to the invention is generally identified with the number 10.

(5) The spindle drive 10 comprises a spindle 12 which has, at its one end, a connection unit 14 for connecting with a superordinate assembly (not shown), such as a door of a vehicle, and at its other end a stop 16 which may serve to limit a translational displacement of the spindle 12.

(6) The spindle 12 is in a threaded engagement with a spindle nut 18 in such a way that a rotation of the spindle nut 18 causes a translational displacement of the spindle 12 relative to the spindle nut 18 when the spindle 12 is rotatably connected to the superordinate assembly.

(7) The spindle nut 18 is accommodated in a cage element 20 with the spindle nut 18 being mounted pivotably relative to the cage element 20 around a pivot axis X. The pivot axis X is formed here by two opposing pins which connect the spindle nut 18 with the cage element 20.

(8) The cage element 20 here has two pin-shaped projections 22 which together define a second pivot axis Y. In each case, a follower 24 is arranged on the two pin-shaped projections 22 with the followers 24 and the cage element 20 being mounted so as to be rotatable around the pivot axis Y.

(9) The followers 24 are received in corresponding recesses 26 of a base element 28 of a drive element 30 of the spindle drive 10 according to the invention. The followers 24 are fixed in the recesses 26 in such a way that they are not displaceable rotationally relative to the base element 28. For the translational fastening of the follower 24 in the base element 28, a cover element 32 of the drive element 30 is connected to the base element 28 wherein, in the illustrated embodiment, the base element 28 and the cover element 32 are connected to the drive element 30 by screws 34. The cover element 32 connected to the base element 28 clamps the followers 24 between itself and the base element 28.

(10) The mounting of the spindle nut 18 and/or the spindle nut 18 together with the cage element 20 in the drive element 30 described above allows for a pivoting of the spindle nut 18 and thus of the spindle 12 relative to the drive element 30 in any direction.

(11) To limit a pivot range of the spindle 12 relative to the drive element 30, both the base element 28 and the cover element 32 comprise tapered openings 36 and 38 whose walls the spindle 12 may strike when it reaches the end of the defined pivot range.

(12) The spindle nut 18 is here spherically formed at least on the surfaces which protrude from the cage element 20 so as to allow an unimpeded displacement of the spindle nut 18 in the drive element 30.

(13) The drive element 30 is rotatably mounted together with the followers 24, the cage element 20, and the spindle nut 18 in a housing of the spindle drive 10 via bearings 40, for example ball bearings.

(14) The base element 28 of the drive element 30 has, on its outer circumference, a toothing 42, which is in engagement with a gear wheel 44, whose axis of rotation Z is parallel to a longitudinal axis A of the spindle 12, in the orientation of the spindle 12 shown in FIG. 1 as substantially parallel. The gear wheel 44 is driven by a drive unit 46 wherein a driven shaft 48 of the drive unit 46 has a central axis which lies on the axis of rotation Z.

(15) Between the drive unit 46 and the gear wheel 44, a friction brake 50 is arranged which, depending on its braking force, for example, prevents a pushing or pulling force acting on the connection unit 14 from causing a rotation of the drive element 30 without the drive unit 46 being activated.

(16) Furthermore, a planetary gear 52 is arranged between the drive unit 46 and the gear wheel 44 which provides a ratio of the rotational speed and the torque of the driven shaft 48 of the drive unit 46 to the rotational speed and the torque of the gear wheel 44.

(17) An activation of the drive unit 46 thus causes a rotation of the gear wheel 44 which causes the drive element 30 to start rotating on the basis of the toothing of the base element 28 with the gear wheel 44 in the sense of a spur gear toothing. The rotation of the drive element 30 is transmitted to the spindle nut 18 by means of the followers 24 and the cage element 20. Due to the threaded engagement of the spindle nut 18 with the spindle 12, a rotation of the spindle nut 18 in turn causes the spindle 12 to be translationally displaced relative to the same according to the rotational direction of the spindle nut 18.

(18) FIG. 2 shows a second embodiment of a spindle drive 110 according to the invention which essentially differs from the spindle drive 10 shown in FIG. 1 only in that a worm toothing is provided instead of the spur gear toothing between the gear wheel 44 and the base element 28. Therefore, components of the spindle drive 110, which are similar to those components of the spindle drive 10, are provided with the same reference numerals but increased by the number 100. With respect to the components and the description of the spindle drive 110, reference is hereby expressly made to the description relating to the spindle drive 10.

(19) The spindle drive 110 comprises a drive element 130 which comprises a cover element 132 and a base element 128. A worm wheel 156 is connected to the base element 128 with the base element 128 here being integrally formed with the worm wheel 156. The worm wheel 156 has an axis of rotation A′ which is coaxial with the base element 128. In the exemplary embodiment illustrated in FIG. 2, the worm wheel 156 has a smaller outer diameter than the base element 128.

(20) A worm 158 is engaged with the worm wheel 156 so that a rotation of the worm 158 causes a rotation of the worm wheel 156.

(21) The axis of rotation B of the worm 158 is substantially orthogonal to the axis of rotation A′. At least one drive unit 146, but also a friction brake 150 and a planetary gear 152, may be connected to the worm 158. A driven shaft 148 assigned to the drive unit 146 may have a longitudinal axis which is parallel to the axis B, in particular coaxial.

(22) With regard to further components, features, and functions of the spindle drive 110, explicit reference is made at this point once again to the description of the spindle drive 10.

(23) FIG. 2 shows as well that a pin-shaped projection 122 is inserted into a spindle nut 118 by using an intermediate element 160. The pin-shaped projection 122 together with the intermediate element 160 is pressed here into the spindle nut 118.