Back to results
US 2025/0092939 A1Published application
Ball screw device and electric actuator provided with same
AssigneeNTT, Inc.
InventorsYuta OKU, Akio KATO
Life of this patent
Estimating the term…
Abstract
A ball screw device 4 includes a screw shaft 9 having a screw groove 9a formed in an outer peripheral surface, a nut 8 having a screw groove 8a formed in an inner peripheral surface, and a large number of balls 10 arranged between the screw groove 9a of the screw shaft 9 and the screw groove 8a of the nut 8. A ratio Δr/L1 of a radial gap Δr, which is a maximum amount of radial movement of the nut 8 with respect to the screw shaft 9, to an axial span L1 between the large number of balls 10 is made larger than 1/2000.
Claims6
A ball screw device comprising:
- a screw shaft having a screw groove formed in an outer peripheral surface;
- a nut having a screw groove formed in an inner peripheral surface;
- and
- a large number of balls arranged between the screw groove of the screw shaft and the screw groove of the nut,
- one of the screw shaft and the nut being caused to function as a rotating body and the other being caused to function as an axially moving body, wherein
- a ratio Δr/L1 of a radial gap Δr, which is a maximum amount of radial movement of the nut with respect to the screw shaft, to an axial span L1 between the large number of balls is larger than 1/2000.
3 more elements
Dependencies are inferred from the claim text.