Ball circulating member and ball screw

A ball circulating member for use in a ball screw including a threaded shaft having a ball rolling groove formed in an outer peripheral surface thereof, a nut having a ball rolling groove formed in an inner peripheral surface thereof opposed to the outer peripheral surface of the threaded shaft, and a plurality of balls provided in a ball track passageway formed between the ball rolling grooves of the nut and the threaded shaft;

• the ball circulating member comprising:
• a ball circulating passageway which is formed therein to scoop-up the balls from the ball track passageway at one side thereof and to return the scooped-up balls to the ball track passageway at the other side thereof;
• the ball circulating passageway including a central passageway, and a pair of guide passageways formed respectively at opposite ends of the central passageway in continuous relation thereto, wherein
• an outer surface of each of peripheral walls, respectively forming the guide passageways, is disposed substantially parallel to a path of movement of the balls in the corresponding guide passageway, and
• a thickness of each of the peripheral walls, respectively forming the guide passageways, is substantially equal to a thickness of a peripheral wall forming the central passageway.

A ball circulating member for use in a ball screw including a threaded shaft having a ball rolling groove formed in an outer peripheral surface thereof, a nut having a ball rolling groove formed in an inner peripheral surface thereof opposed to the outer peripheral surface of the threaded shaft, and a plurality of balls provided in a ball track passageway formed between the ball rolling grooves of the nut and the threaded shaft;

• the ball circulating member comprising:
• a ball circulating passageway which is formed therein to scoop-up the balls from the ball track passageway at one side thereof and to return the scooped-up balls to the ball track passageway at the other side thereof;
• the ball circulating passageway including a central passageway, and a pair of guide passageways formed respectively at opposite ends of the central passageway in continuous relation thereto, wherein
• a foreign matter intrusion prevention lid portion for preventing a foreign matter from intruding through a respective one of ball circulating member-mounting holes, which are formed in the nut to mount the ball circulating member therein, is formed on the outer surface of each of the peripheral walls, respectively forming the guide passageways, through the foreign matter intrusion prevention lid-supporting portion which is formed substantially upright on the outer surface of the peripheral wall in a manner to support the foreign matter intrusion prevention lid portion.