A ball unit (10), in particular for conveying devices (1), possesses a load ball (12), which by a part (14) of its surface can bear against a load object, a bearing unit (24), which so bears and encloses the load ball to be freely rotatable that a free part (14) of the load ball surface projects out of the bearing unit through a circular passage opening (61), and a holder (20), which for fastening of the ball unit at a carrier frame of the conveying device displays a fastening portion (31), which can be borne on the carrier frame. The bearing unit (24) is so linearly movable to and fro relative to the holder (20) that the free load ball surface in an advanced end position protrudes further beyond a surface (3) of the carrying frame than in a withdrawn end position. Stressed between bearing unit and holder is a spring (18), which is constructed as flatly bowed annular washer, supported against the holder in immediate proximity of its fastening portion, is arranged concentrically with the passage opening of the bearing unit and biasses the bearing unit into the advanced end position.