US 12,276,321 B2
Ball screw device
Ryo Segawa, Fujisawa (JP)
Assigned to NSK LTD., Tokyo (JP)
Appl. No. 18/030,200
Filed by NSK LTD., Tokyo (JP)
PCT Filed Jun. 16, 2022, PCT No. PCT/JP2022/024123
§ 371(c)(1), (2) Date Apr. 4, 2023,
PCT Pub. No. WO2023/282012, PCT Pub. Date Jan. 12, 2023.
Claims priority of application No. 2021-111207 (JP), filed on Jul. 5, 2021.
Prior Publication US 2023/0375081 A1, Nov. 23, 2023
Int. Cl. F16H 25/20 (2006.01); F16H 25/22 (2006.01)
CPC F16H 25/2214 (2013.01) 10 Claims
OG exemplary drawing
 
1. A ball screw device including:
a screw shaft having a shaft-side ball thread groove with a spiral shape on an outer-circumferential surface thereof and rotationally moving during use,
a nut having a nut-side ball thread groove with a spiral shape on an inner-circumferential surface thereof and linearly moving during use,
balls arranged between the shaft-side ball thread groove and the nut-side ball thread groove,
a housing having an insertion hole through which the nut can be inserted in an axial direction, and
a rotation restraining member for preventing relative rotation of the nut with respect to the housing,
the nut having a guide concave groove on an outer-circumferential surface, the guide concave groove capable of engaging with the rotation restraining member in a circumferential direction,
the insertion hole having a retaining concave groove on an inner-circumferential surface, the retaining concave groove capable of engaging with the rotation restraining member in the circumferential direction, and
the rotation restraining member configured by a shaft-shaped member extending in the axial direction, and having an outside portion in a radial direction thereof arranged inside the retaining concave groove and an inside portion in the radial direction arranged inside the guide concave groove so as to be able to relatively slide in the axial direction,
wherein
the nut has a circulation groove on the inner-circumferential surface, and
the guide concave groove is arranged so as to be shifted from the circulation groove in the circumferential direction.