| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball screw capable of uniformly applying a thrust load in the circumferential direction. SOLUTION: This shaft circulating type ball screw constitutes a plurality of ball circulating rows 21 and 22 for returning to the upstream side by getting over a land part 17 of a nut 11, by sinking a downstream ball of screw grooves 13a and 13b in the inner diameter side by these ball circulating grooves 15 and 16, by arranging a plurality of ball circulating grooves 15 and 16 with a plurality of screw grooves 13a and 13b individually as a closed loop, in a land part 14 existing between the adjacent screw grooves in the axial direction of a screw shaft 13, and is characterized by equally arranging a phase in the peripheral direction of the ball circulating grooves 15 and 16 of the respective ball circulating rows 21 and 22, by separately arranging the ball circulating rows 21 and 22 by one pitch or more. COPYRIGHT: (C)2010,JPO&INPIT |
