公开(公告)号：US12222024B1

公开(公告)日：2025-02-11

申请号：US18612954

申请日：2024-03-21

Applicant: APPLE INC.

Inventor： Sina Mobasher Moghaddam ,  Troy A. Carter ,  Jonathan L. Hall

IPC: F16H25/22 ,  B60G17/00 ,  F16H25/20

Abstract: A ball screw spline actuator includes a shaft, a ball nut, and a ball spline. The shaft includes a helical groove and a spline groove intersecting the helical groove forming intersections having a least one ridge including a first surface finish formed by a first manufacturing operation. The ridge is subsequently reformed through a second manufacturing operation to include a second surface finish to reduce stress concentrations in the ridge from cyclical loading from at least one of the ball nut or the ball spline. In one example, the second manufacturing operation reforms the ridge to include a surface finished edge.