Circulation member, motion guide device provided with circulation member and ball screw provided with circulation member

A ball screw comprising:

• a screw shaft formed, on an outer periphery thereof, with a spiral ball rolling groove;
• a nut assembled with the screw shaft and formed, on an inner periphery thereof, with a spiral loaded ball rolling groove so as to oppose to the ball rolling groove formed on the screw shaft to thereby form a ball rolling passage;
• a number of balls disposed in the ball rolling passage;
• a number of spacers disposed between the balls in the ball rolling passage;
• and
• a circulation member for circulating a number of balls and spacers, each spacer being disposed between the balls in accordance with a relative motion of the nut with respect to the screw shaft, wherein the circulation member is provided with a scoop-up groove for scooping the balls by contacting the ball rolling in the ball rolling passage at both side edge portions of the scoop-up groove and is provided with a spacer scoop-up portion which contacts and scoops the spacer moving in the ball rolling passage without contacting the balls.

A motion guide device comprising:

• a track rail formed with a ball rolling groove;
• a slide member mounted to the track member to be relatively movable with respect thereto and is formed with a loaded ball rolling groove so as to oppose to the ball rolling groove of the track member to thereby form a ball rolling passage;
• a number of balls disposed in the ball rolling passage;
• a number of spacers disposed between the balls in the ball rolling passage;
• and
• a circulation member for circulating a number of balls and spacers, each spacer being disposed between the balls in accordance with a relative motion of the slide member with respect to the track member, wherein the circulation member is provided with a scoop-up groove for scooping the balls by contacting the ball rolling in the ball rolling passage at both side edge portions of the scoop-up groove and is provided with a spacer scoop-up portion which contacts and scoops the spacer moving in the ball rolling passage without contacting the balls.