FREE BALL BEARING, BEARING DEVICE, SUPPORT TABLE, TRANSFER EQUIPMENT, AND TURN TABLE

摘要

A free ball bearing includes: a main body that has a ball retainer where a ball-retaining recess having an inner surface of a semi-circular recessed surface is formed; a plurality of retainer balls that is disposed on the semi-circular recessed surface of the main body and a main ball that has a diameter larger than the retainer balls and is rotatably supported through the retainer balls; a cover portion that surrounds the ball retainer of the main body while ensuring a predetermined internal space; a retained ball-pressing ring that has a ring-shaped pressing member that is inserted in between the semi-circular recessed surface of the main body and the main ball and presses the retainer balls, and is disposed to be movable in the internal space in the depth direction of the ball-retaining recess, between a pressing position where the retainer balls are pressed and a releasing position where the retainer balls are released; and a releasing mechanism that moves the retained ball-pressing ring from the pressing position to the releasing position by applying a displacement force to the retained ball-pressing ring.