Ball screw drive

Abstract

A ball screw drive (10) including a threaded spindle (12) and a spindle nut (14) which at least partially coaxially encloses the threaded spindle (12) and has a stop at an axial end face (18). A multiplicity of balls can circulate in the space (16) between the threaded spindle (12) and the spindle nut (14). A radial stop element (22) is connected to the threaded spindle (12) in a force-fitting manner and adapted to interact with the complementary axial end face (18) of the spindle nut (14). A bearing element is provided for receiving a first longitudinal end of the spindle nut (12). The radial stop element (22) and the bearing element are designed in combination as an integral bearing/stop element (24) which has two anti-rotation features (26, 28).

Claims

1. A ball screw drive (10), comprising: a threaded spindle (12), a spindle nut (14) which at least partially coaxially encloses the threaded spindle (12) and has a stop on an axial end face (18), a plurality of balls that are adapted to circulate in the space (16) between the threaded spindle (12) and the spindle nut (14); an integral bearing/stop element (24) connected to the threaded spindle (12) in a force-fitting manner, adapted to interact with the axial end face (18) of the spindle nut (14); the integral bearing/stop element receives a first longitudinal end of the threaded spindle (12); first and second anti-rotation features (26, 28) are located on the integral bearing/stop element (24); and the second anti-rotation feature (28) is formed such that the bearing/stop element (24) is adapted to be connected to a further receptacle in a force-fitting manner.

2. The ball screw drive (10) according to claim 1, wherein the first anti-rotation feature (26) is formed such that an angular relationship between the threaded spindle (12) and the bearing/stop element (24) is adapted to be adjusted and subsequently fixed in a force-fitting manner.

3. The ball screw drive (10) according to claim 1, wherein the first anti-rotation feature (26) is comprised of a system including a polygon (30) integrally formed on the threaded spindle (12) or a gear wheel arranged or integrally formed radially on an outside of the threaded spindle, said polygon or gear wheel interacts with an internally toothed bore (32) of the bearing/stop element (24).

4. The ball screw drive (10) according to claim 3, wherein a pitch of the internally toothed bore is an integer multiple of a pitch of the polygon (30) or of the gear wheel arranged radially on the outside of the threaded spindle.

5. The ball screw drive (10) according to claim 1, wherein the stop (20) on the axial end face (18) of the spindle nut (14) comprises a projection, a cantilever or a clearance.

6. The ball screw drive (10) according to claim 1, further comprising at least one radial stop (34) on the bearing/stop element (24) and comprises a projection, a cantilever, or a clearance.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically shows a BSD with axial stop.

(2) FIG. 2 shows a BSD with an inventive bearing/stop element 24 with two anti-rotation features.

(3) FIG. 3A shows a BSD in the assembled state with an inventive bearing/stop element 24 in cross section.

(4) FIG. 3B shows a BSD in the assembled state with an inventive bearing/stop element 24 in side view.

DETAILED DESCRIPTION

(5) FIG. 1 shows a BSD 10 with the most elementary components, a threaded spindle 12 and spindle nut 14, which, due to their opposing internal and external threads, form a space 16 between them, which acts as a ball guide. The normally provided ball deflection, which allows a closed circulation of the balls, is omitted. At one end of the threaded spindle 12, a flat stop plate 22 is shown. The latter would rest against the stop face 18 on the end face side as soon as the spindle nut 14 in the drawing would move to the right in the drawing. Such a simple flange stop has the disadvantages described above.

(6) FIG. 2 shows a BSD 10 with the well-known basic elements threaded spindle 12 and spindle nut 14 together with an inventive bearing/stop element 24 with two anti-rotation features. The first anti-rotation feature 26 is the combination of the polygon 30 (shown as a hexagon) and an internally toothed bore 32. The drawing illustrates that this internal toothing has a smaller pitch than the external hexagon 30. As a result, the relative angular relationship between the bearing/stop element 24 and the threaded spindle 12 can be adjusted when plugging them together. Fixing can then be carried out using a split pin, a circlip or by caulking, casting, welding or gluing.

(7) FIG. 2 shows that the stop 20 on the end face 18 of the spindle nut 14 is designed as a projection which can interact with a complementary stop 34 of the bearing/stop element 24. The dimensioning of the stop is determined, among other things, by the thread pitch of the BSD, which ensures the safest possible stop face.

(8) The second anti-rotation feature 28 is shown here as a square outer contour with rounded corners, which can be mounted in a receptacle (not shown) of a housing or bearing.

(9) FIG. 3A shows a BSD 10 in the assembled state with an inventive bearing/stop element 24 in cross-section, FIG. 3b shows a side view. The meaning of the reference symbol is as described above. The situation shown shows the spindle nut 14 in the end stop position at the bearing/stop element 24. FIG. 3B shows how the stop 20 interacts with its counterpart 34. The cross-section clearly shows that there is no jamming at the front face of bearing/stop element 24 and spindle nut 14. FIG. 3B clearly shows that the bearing/abutment element 24 with its outer contour is exposed and can thus be used as an anti-rotation feature. The combination of FIGS. 3A and 3B also illustrates how the bearing, anti-rotation feature and stop can be combined in a compact manner.

(10) The features of the invention disclosed in the above description, in the drawings and in the claims may be essential for the implementation of the invention, either individually or in any combination which is technically useful or advantageous.