Patent ID: 7862234
Filing Date: 2011-01-04
Classification: F16C

Abstract:
1. A linear motion guide unit, comprising: an elongated guide rail having a raceway surface extending in a lengthwise direction of the guide rail, and a slider allowed to move lengthwise of the elongated guide rail in a sliding manner, the slider being composed of a carriage having thereon a second raceway surface in opposition to the first raceway to define a load-carrying race between them and having therein a return passage extending in parallel with the load-carrying race, end caps secured to forward and aft ends of the carriage, one to each end, and made therein with turnaround passages joining the race and the return passage together with one another, an end seal secured on the end cap, and more than one rolling element of either ball or roller allowed to roll through a circulating circuit made up of the load-carrying race, return passage and the turnaround passages; wherein the end caps are each made to sink along the lengthwise direction below an outward surface thereof facing the associated end seal to thereby have a deep recess into which fits a porous compact of a shape conforming to the recess, the porous compact being impregnated with lubricant; wherein the end cap has a hole to communicate the recess with the associated turnaround passage to allow the porous compact exposing itself to the turnaround passage, coming into rolling-contact with the rolling element rolling through the turnaround passage to apply the lubricant on the rolling element; wherein the recess made in the end cap includes a deep cavity lying at topside of the end cap, a shallow shelf spreading downwards from the topside of the end cap, and a pit extending from the shelf to the hole that opens into the turnaround passage; and wherein the porous compact is composed of a thick block to fit into the deep cavity in the recess to reserve considerable lubricant, a thin plate to conform to the shallow shelf in conjunction with the thick block, and a nose raised above the thin plate to extend into the associated pit in a way leading lubricant to the hole opening to the turnaround passage.