| 摘要 |
PURPOSE:To reduce the height over all a bearing unit in such a way that endless circulating ball trains are arranged in four trains so as to be able to bear each load from upward and downward, from the left and the right, and by torsion, and any of return holes is formed above the tracks in the loaded zone. CONSTITUTION:A rail 1 is formed in such a way that its tracks 3-6 are arranged respectively on two areas of the upper side and both left and right sides along the longitudinal directions. Besides, an upper plate groove 8 inside the gantry of the main body 14, and side plate grooves 9, 10 on both left and right sides are respectively formed in a slide casing 2 which bestrides the rail 1, and bearing plates 11-13 are respectively attached to and tightly fixed in each groove. Then, tracks 18-21 are respectively formed at the parts corresponding to said tracks, 3-6 on each plate 11-13, and each of ball trains 22, 23, 26, 27 is inserted between a pair of parts of each track. In addition, four return holes 24, 25, 28, 29 are formed in the casing 2, so that each ball train 22, 23, 26, 27 can be circulated through shifting paths 33 on the both ends. |
