Patent ID: 8641280

Claim:
A linear motion guide unit prolonged in service life for lubrication comprising an elongated guide rail, a slider movable lengthwise of the elongated guide rail in a sliding manner, and a rolling element allowed to roll through a load-carrying race defined between the guide rail and the slider; wherein the slider has a carriage, end caps and end seals, the carriage having a return passage extending in parallel with the load-carrying race, the end caps being fastened on forward and aft end surfaces of the carriage, one to each end surface, and provided therein with turnaround passages to join together the load-carrying race and the return passage, and the end seals being attached on outward end surfaces of the end caps; wherein the end caps each have a lubricant applicator constituted with a lubricant reservoir plate and an applicator nose, the lubricant reservoir plate being made of a porous compact having open pores impregnated with lubricant, the applicator nose being made of a porous compact which has open pores and protrudes from the lubricant reservoir plate, the applicator nose having a leading edge which extends through a hole in the end cap to come into touch with the rolling element rolling though the turnaround passages, and the lubricant reservoir plate being integral with the applicator nose through coalescence of fine particles of ultra molecular weight synthetic resins in the porous compact; wherein the applicator nose has at least a layer in the porous compact, which is densified in molded density to have pores less in pore size and pore number than in the lubricant reservoir plate so as to restrict an amount of lubricant flowing across the layer; wherein the leading edge of the applicator nose comes into touch with the rolling element to apply the lubricant around the rolling element while rolling through the turnaround passages; and wherein the applicator nose of the porous compact has the molded density of from 0.60 to 0.70 g/cm 2 , and the lubricant reservoir plate of the porous compact has the molded density of from 0.40˜0.60 g/cm 3 .