Recirculating-ball linear bearing and guide rail therefor

In a recirculating-ball linear bearing apparatus capable of withstanding the load acting thereon in four orthogonal directions, comprising:

• (a) guide rail having two pairs of parallel raceways of arcuate cross section, each pair of raceways being vertically spaced, and angled away, from each other;
• (b) a bearing body of substantially inverted-U-shaped cross section mounted astride the guide rail for rolling motion along the same and having two pairs of raceways of arcuate cross section formed longitudinally thereon in opposed relation to the two pairs of raceways on the guide rail, the bearing body also having a return passageway formed longitudinally therethrough in the vicinity of each raceway thereon;
• (c) a pair of end covers secured to the opposite ends of the bearing body and each having formed therein four grooves each intercommunicating one raceway on the bearing body and one adjacent return passageway in the bearing body;
• (d) groups of antifriction balls rollably interposed between the raceways on the guide rail and the raceways on the bearing body, each group of antifriction balls being capable of recirculation along one raceway on the bearing body and through one adjacent return passageway in the bearing body which are in communication with each other via two of the grooves in the end covers;
• and
• (e) cage means for rollably holding the antifriction balls on the raceways on the bearing body and allowing the antifriction balls to make rolling engagement with the raceways on the guide rail;
• the improvement wherein the guide rail comprises a flat flange base adapted to be mounted to a structure, an elongated web extending upwardly from the flange base, and a head on the top of the web, the two pairs of parallel raceways on the guide rail extending longitudinally and being formed on both sides of the head;
• the flange base, the web and the head being integrally formed with each other and jointly serving as a rigid structural member of a building or a frame member of a machine.