Finite linear motion guide unit with cross-roller bearing system

摘要

A synthetic resin-made cage plate to retain rollers lies between guideway members. The smaller pitch between the adjacent rollers in a cage results in the greater number of the rollers lying in a preselected length of the cage to get heavier load-carrying capacity. A holder to receive a pinion is molded integrally with the cage plate. The rollers are retained in openings in the cage plate at a tilt such that their rotating axes are perpendicular to the lengthwise direction of the raceway surfaces and also tilting at 45 degrees relative to major surfaces of the cage plate. The openings on their contour edges have bearing lips to retain end surfaces of the rollers. The cage plate has flanges extending lengthwise on its' widthwise opposite edges and bulging sidewise out over the major surfaces of the cage plate to render the cage plate tougher to warp or bend.

主权项

1. A finite linear motion guide unit with a cross-roller bearing system comprising:
a first guideway member and a second guideway member lying movably relative to one another, each of the guideway members having a longitudinal side confronted with each other and provided thereon with a raceway groove having a V-shape in a transverse section, a plurality of rollers arranged between raceway surfaces opposed to each other on the raceway grooves of the guideway members to roll on the raceway surfaces on the raceway grooves, and a cage plate lying in a longitudinal direction between the longitudinal sides of the guideway members and carrying therein the rollers at preselected intervals in such geometry that axes of alternative ones of the plurality of rollers are perpendicular to each other; wherein the cage plate is a molding of synthetic resin having a front major surface and a rear major surface disposed adjacent to each longitudinal side of the guideway members, the major surfaces being parallel to each other, the cage plate having openings to retain therein the rollers in such geometry that the axes of the rollers tilt at 45 degrees with respect to a widthwise direction of the front and rear major surfaces of the cage plate, each of the openings being provided with a contour edge, each contour edge having bearing lips to bear against one of the plurality of rollers for rotation; further the cage plate having, on widthwise opposite edges thereof, flanges which extend longitudinally along an entire length of the cage plate and bulge out from the front and rear major surfaces of the cage plate to reinforce stiffness and rigidity of the cage plate across the entire length of the cage plate, to reduce warping and bending of the cage plate in the longitudinal direction of the cage plate, and to prevent the rollers from falling away from the cage plate, wherein the bearing lips are formed in pairs in opposition to each other in the widthwise direction of the cage plate, and the bearing lips each have a thickness of half a dimension between the major surfaces of the cage plate, and a respective remaining half of the dimension between the major surfaces of the cage plate adjacent to each bearing lip is cut away to form a concavity in a perpendicular direction with respect to the major surfaces, wherein the cage plate is smaller in a widthwise dimension than a widthwise dimension of the guideway member and the flanges on the lengthwise edges of the cage plate are stowed inside the overall width of the guideway member, and further the flanges have a transverse section having a triangular shape, the flanges each comprise a top that is coplanar with an outer edge of each plate, the flanges fit inside a space defined between beveled edges of the guideway members lying in opposition to each other, and wherein the front major surface and the rear major surface of the cage plate are substantially flat or even around the openings along the entire length of the cage plate and the openings each have a contour of an ellipse having a major axis lying in a widthwise direction of the cage plate to fit over the roller while bearing the roller for rotation in the opening.