JPS5682143A - Direct-acting guide apparatus - Google Patents

Abstract

PURPOSE:To improve the rolling guide surfaces of a direct-acting guide apparatus in straightness and parallelism between them by forming a pair of rolling grooves in a raceway shaft, arranging the rolling surfaces for balls on the raceway shaft into two places and forming said grooves into Gothic arch shape. CONSTITUTION:The sectional geometry of a raceway shaft 1 is a rectangle having laterally extending upper and lower surfaces. At two corners where both side surfaces and the upper surface of the raceway shaft 1 cross each other, axial grooves 1' are formed for rolling balls. Between the raceway shaft 1 and a direct-acting slider 2 guided by the raceway shaft 1, a direct-acting ball bearing whose circumferential fixed area has been axially cut is fixed. A large number of balls 6 forming two rows and circulating in the ball bearing are simultaneously contacted between the rolling grooves 1' in the raceway shaft 1 and rolling grooves 3' formed in the inner circumferential surface of a bearing outer drum 3 within a load supporting range. Moreover, screws 7 are used to cope with the minute change of the outer drum 3 resulting from the clamping forces from the directions of the point where the center lines of the rolling grooves 3' cross each other, so that a preload is effectively applied to the balls to roll.