Patent ID: 7434999
Filing Date: 2008-10-14
Classification: F16C

Abstract:
1. A linear motion guide unit with a retainer; comprising an elongated guide rail having a first raceway surface extending lengthwise of the guide rail, and a slider having a second raceway surface in opposition to the first raceway surface, the slider being allowed to move relatively of the elongated guide rail by virtue of a roller, which rolls through a race defined between the first and second raceway surfaces; wherein a retainer is provided to accommodate a roller therein; wherein the retainer has embracing parts which engage a rolling surface of the roller at diametrically opposite sides thereof, and a pair of connecting flanges lying above axially opposite ends of the roller and connecting integrally the embracing parts with each other; wherein each of the embracing parts are made with first lips raised above any one side of the associated embracing part to come into contact with the roller, and a second lip raised above another side of the associated embracing part to come into contact with the roller; wherein the first and second lips are placed in a staggered relation with one another in an axial direction of the roller; wherein the first lips are made at two locations spaced away from one another to retain the roller at opposite ends thereof spaced away each other in axial direction, while the second lip is made at one location complementary to the first lips to retain the roller at a middle area lying between the opposite ends thereof; wherein the slider is comprised of a carriage made therein with a return passage extending lengthwise in parallel with a load-carrying race defined between the first raceway surface on the guide rail and the opposing raceway surface on the slider, end caps arranged on forward and aft ends of the carriage and made therein with turnaround passages to communicate the load carrying race with the return passage, and wherein the retainer harboring the roller therein is allowed to travel through a circulating circuit composed of the load-carrying race, return passage and paired turnaround passages, and wherein the embracing part fits into the circulating circuit in a way that the first lips travel along the outer side of the circulating circuit while the second lip runs along the inner side of the circulating circuit, and wherein there is left a clearance between the second lip and the rolling surface of the roller.