公开(公告)号：US20240003410A1

公开(公告)日：2024-01-04

申请号：US18037165

申请日：2021-11-12

Applicant: Hitachi Astemo, Ltd.

Inventor： Koji USUI ,  Ryo UEYAMA ,  Takenori ISO ,  Hiromu NARUKAWA

IPC: F16H25/24 ,  F16H57/04

CPC classification number: F16H25/24 ,  F16H57/0464 ,  F16H57/0497 ,  F16H2025/2081

Abstract: An electric actuator includes an electric motor, a nut (a first screw member), and a screw shaft (a second screw member) threadedly inserted through the nut to be able to advance and retreat. Each of threads of the screw shaft includes two flanks and a crest portion connecting the flanks to each other. Grease is used as a lubricant. A groove portion, which is cut out from the crest portion toward a root portion side, is formed on each of the threads of the screw shaft. Further, a taper surface, which flares becoming circumferentially farther away from the groove portion, is formed on at least a part of each of peripheral edges of each groove portion on flank sides. The electric actuator can promote lubrication of a threadedly engaged portion between the first and second screw members, thereby improving motion conversion efficiency and reducing wear on the threadedly engaged portion.