Recirculating-ball linear bearing

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

• (a) a body of substantially inverted-U-shaped cross section having two opposed pairs of raceways of arcuate cross section formed longitudinally on inner surfaces thereof, each pair of raceways being vertically spaced from and angled toward each other, the body also having a return passageway formed longitudinally therethough in the vicinity of each raceway, the body comprising a bridge portion and a pair of aprons depending from its opposite sides, and wherein the aprons have a sufficient thickness to have the return passageways formed therethough without suffering a substantial decrease in strength or rigidity;
• (b) a pair of end covers secured to the opposite ends of the body, each end covering being of substantially the same shape and size as the cross section of the body and being segmented into a pair of lateral halves, each half of each end cover having formed therein two hairpin passageways each inter-communicating one raceway and one adjacent return passageway in the body, each half of each end cover also having a retainer groove formed therein;
• (c) a group of recirculating antifriction balls capable of rolling along each raceway and through one adjacent return passageway communicated therewith via the hairpin passageways, each raceway on the body being, as viewed cross-sectionally, curved with a radius approximately equal to the radius of each antifriction ball, and wherein the planes passing the longitudinal median lines of the raceways and the centers of the antifriction balls thereon are angularly spaced 90 degrees from each other, the return passageways associated with each pair of raceways on the body being disposed inwardly of the planes passing the longitudinal median lines of the raceways and the centers of the antifriction balls thereon so as to reduce the vertical dimension of the body, each of said two hairpin passageways in each end cover being curved away from the assocated raceway toward the associated return passageway while departing gradually away from the planes passing the longitudinal median lines of the raceways and the centers of the antifriction balls thereon;
• and
• (d) a pair of cages extending along one pair of raceways on the body for rollably holding the antifriction balls thereon and supported in position by having the opposite ends thereof closely engaged in the retainer grooves in the pair of end covers, each cage being in the form of a strip of rigid material bent substantially into the shape of a V in cross section to provide a pair of divergent web portion of each cage having formed therein a slot extending along one raceway on the body having width less than the diameter of each antifriction ball to allow the antifriction balls to partly project inwardly therethrough as they roll along the raceway.