Patent ID: 8858080

Claim:
A linear motion guide unit comprising: an elongated guide rail having on both sides thereof first raceway grooves extending in a longitudinal direction of the guide rail, and a slider that fits over or conforms to the guide rail to move in the longitudinal direction of the elongated guide rail in a sliding manner, the slider being composed of a carriage and end caps, the carriage having second raceway grooves extending in opposition to the first raceway grooves on the guide rail to provide load-carrying races between the first and second raceway grooves and return passages extending along the load-carrying races, the end caps being fastened on end surfaces opposed in the longitudinal direction of the carriage, one to each end surface, and provided therein with turnaround passages extending with curvature to connect the load-carrying races with the return passages, and the slider including a plurality of balls, which are allowed to roll through circulating circuits made up of the load-carrying races, return passages and the turnaround passages, and porous compacts impregnated with lubricant and stowed in concavities recessed below end surfaces of the end caps in a sliding direction of the slider, wherein each of the turnaround passages on outside curved wall portions thereof have a slot connecting the concavities in the end caps to the turnaround passages, the slots being each elongated in a rolling direction of the ball and rounded at lengthwise opposite ends thereof, each of the porous compacts having an applicator nose extending through the respective slot to provide end surfaces exposed to the turnaround passages, and the balls while rolling through the turnaround passages being guided along the slots to make rolling contact with the exposed surfaces of the porous compacts to be applied with the lubricant impregnated in the porous compacts, wherein the exposed surfaces of the applicator noses are each set back below the opposite ends of the respective slot and edges which extend in parallel with each other to connect the opposite ends of the slot to each other, so that spherical surfaces of the balls, while rolling along the outside curved wall portions of the turnaround passages, protrude in part through an interval between the edges of the respective slot to come into rolling contact with the exposed surfaces, and wherein the balls, while protruding in part through the interval between the edges of the respective slot, come into at least one-point contact with the contact areas of the exposed surface midway between the opposite ends of the respective slot.