Patent ID: 6476525
Filing Date: 2002-11-05
Classification: B23Q,F16C,F16H,H02K

Abstract:
A linear actuator comprising:a guide rail provided with ball-rolling grooves extending in a major axis direction on both side surfaces and formed with a concave groove having a substantially U-shaped cross section; a ball screw shaft arranged substantially in parallel to said ball-rolling grooves at a central portion in a widthwise direction substantially perpendicular to said major axis direction of said guide rail; bearings for supporting said ball screw shaft at both ends in said major axis direction of said guide rail; a slider formed with endless circulating passages including ball-rolling grooves opposed to said ball-rolling grooves of said guide rail so that said guide rail faces an interior of a recess; a ball screw nut installed to a recess of said slider, for making engagement with said ball screw shaft; and a screw guide member for movably supporting said ball screw nut, said linear actuator further comprising: a floating mechanism for absorbing fine movement of said ball screw nut in a direction substantially perpendicular to a displacement direction on a substantially horizontal plane, and fine movement of said ball screw nut in a substantially vertical direction respectively.