| 摘要 |
PURPOSE:To keep a nut and a ball from partial abrasion and flaking by forming a plurality of transfer grooves on the inner peripheral surface of the nut surrounding a screw shaft of a ball screw, and circulating a line of balls through return holes in the nut. CONSTITUTION:A plurality of spiral passages are formed by transfer grooves 102-105 of a nut 101 and a spiral raceway groove of a screw shaft 201. Balls 110 in the plural spiral passages are advanced with rotation of the screw shaft 201, and carried to return holes 106-109 through grooves 303-310 opened in the tangential direction of one of end caps 301, 302. The balls 110 in the return holes 106-109 are sequentially circulated from the grooves 303-310 opened in the tangential direction of the other of the end caps 301, 302 to the other spiral passage. Thus, all balls 110 are passed through all the spiral passages to equalize abrasion of the balls 10 and the nut 101. |
