Ball screw drive having an axially supported threaded spindle

1. A ball screw comprising a threaded spindle which is mounted in a rolling fashion by balls on a threaded nut and which is supported on an axial bearing, the threaded spindle is axially supported with a first bearing surface, which is convexly shaped with a radius of curvature (R 1 ), on a conically designed second bearing surface, wherein the first bearing surface and the second bearing surface make contact with one another along a contact path, and a quotient formed from a ratio of the radius of curvature (R 1 ) to the radius (R 2 ) of the contact path has values of between 1.2 and 2.4 inclusive.

2. The ball screw as claimed in claim 1 , wherein the quotient is between 1.4 and 1.6 inclusive.

3. The ball screw as claimed in claim 1 , wherein a central point of the radius of curvature (R 1 ) lies on a longitudinal axis (S) of the threaded spindle.

4. The ball screw as claimed in claim 1 , wherein at least one of the first and second bearing surfaces is provided with pockets for receiving lubricant.

5. The ball screw as claimed in claim 1 , wherein the axial bearing has a support disk which is connected to the threaded spindle in a positively locking manner in a rotational direction, the second bearing surface being formed on a side of said support disk which faces toward the threaded nut.

6. The ball screw as claimed in claim 5 , wherein the support disk is arranged to perform a wobbling motion on the threaded spindle.

7. The ball screw as claimed in claim 5 , wherein the support disk is provided, on a side facing away from the threaded nut, with an axial bearing surface which is formed directly on the support disk or on a bearing disk which adjoins the support disk.