US 6,584,869 B2Granted

Ball screw

AssigneeMannesmann Sachs AG

InventorsWolfgang Grosspietsch, Angelika Ebert, Markus Heiartz, Wolfgang Reisser, Andreas Dau, Paul Kraus, Thomas John

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Abstract

A ball screw includes a spindle element which has a first groove arrangement on an outer circumferential surface, a nut element which surrounds the spindle element and has a second groove arrangement on an inner circumferential surface, and a plurality of balls, at least some of which engage into the first groove arrangement and the second groove arrangement. The nut element is rotatable about an axis of rotation with respect to the spindle element, and, during the rotation of the nut element about the axis of rotation with respect to the spindle element, the balls which engage into the first groove arrangement and the second groove arrangement roll in the first and the second groove arrangement, while at the same time rotate about respective ball axes of rotation. In this case, there is provision, with respect to the ball axis of rotation, for an effective ball rolling radius with which the balls roll in the first groove arrangement to be smaller than the effective ball rolling radius with which the balls roll in the second groove arrangement.

Claims7

Dependent claims

A ball screw, comprising:

a spindle element having an outer circumferential surface with a first groove arrangement having a first rolling surface region;
a nut element surrounding the spindle element and being rotatable about an axis of rotation relative to said spindle element, said nut element having an inner circumferential surface with a second groove arrangement having a second rolling surface region;
and
a plurality of balls engaging in said first and second groove arrangements, said balls contacting said first and second groove arrangements at respective said first and second rolling surface regions, said balls being arranged to roll on said first and second rolling surface regions and to simultaneously rotate about respective ball axes of rotation as said nut is rotated relative to said spindle, each said ball having a first effective ball rolling radius between the respective ball axis of rotation and the first rolling surface region, and a second effective ball rolling radius between the respective ball axis of rotation and the second rolling surface region, each said first effective ball rolling radius being smaller than the respective said second effective ball rolling radius.

1 more element

Dependencies are inferred from the claim text.