| 摘要 |
PROBLEM TO BE SOLVED: To surely perform reciprocal motion conversion between rotation and rectilinear motion by providing a bearing which is fitted and held in a rotating cylinder and abuts on the outer periphery of a moving shaft to bear radial load applied to the moving shaft. SOLUTION: Feed rings 11, 11 held in a rotary cylinder are ball bearings which hold many balls between an outer ring and an inner ring and an inside diameter enough larger than the outside diameter of a rack shaft 2, and installed with the shaft center inclined to the rotary cylinder inside the rotary cylinder. A bearing 4 is fitted and held between the feed ring on one side and the feed ring in the center inside the rotary cylinder and pressed to the outer peripheral surface of a rack shaft 2 to bear the radial load applied to the rack shaft 2. Thus, the feed ring engaged with a screw groove formed in the outer periphery of the moving shaft is not needed to bear the radial load, so that the motion conversion from the rotary motion to the rectilinear motion of the moving shaft or its reverse conversion can be surely performed. |
