| 摘要 |
PURPOSE:To reduce the wear of a retainer and rollers, by engaging a plurality of balls rotatably in guides to hold the retainer relative to the guides. CONSTITUTION:A retainer 13 has a plurality of holes 13a in which rollers 2 are housed. The retainer 13 has other holes 13c in which balls 4 are rotatably housed. The diameter of the balls 4 is almost equal to that (d) of the rollers 2. The balls 4 are rotatably engaged in the grooves 5 of guides 1a, 1b as the rollers 2 are. The retainer 13 is held as to the guides 1a, 1b by the plural balls 14 rotatably engaged in the guides and is put in contact with only the peripheral surfaces of the rollers 2 to keep them at inervals. This results in reducing the wear of the retainer 13, the rollers 2, etc. |
