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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
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.