To provide a ball screw, which has a compact size while maintaining differential characteristic.
The ball screw 1 comprises a screw shaft 11, a differential nut 12, and a nut 13. A first thread part 21 is provided on the outer circumferential surface of the screw shaft 11, and a second thread part 31 opposed to the first thread part 21 is provided on the inner circumferential surface of the differential nut 12. An inner retainer 41 is disposed between the first thread part 21 and the second thread part 31, and an inner ball 51 is rotatably positioned in a ball retaining hole 42 of the inner retainer 41. A third thread part 61 is provided on the outer circumferential surface of the differential nut 12, and a fourth thread part 62 opposed to the third thread part 61 is provided on the inner circumferential surface of the nut 13. An outer retainer 71 is disposed between the third thread part 61 and the fourth thread part 62, and an outer ball 81 is freely rotatably positioned in a ball retaining hold of the outer retainer 71.
FUKUOKA MANKI
TAMURA YASUYUKI
MOTOHASHI SHIGEYUKI
UNIV SHINSHU
| JP2004210066A | 2004-07-29 | |||
| JP2004301135A | 2004-10-28 | |||
| JPH03213753A | 1991-09-19 | |||
| JPS5899551A | 1983-06-13 |