| 主权项 |
1. A linear motion guide unit comprising an elongated guide rail having a first raceway groove extending lengthwise of the guide rail and a slider allowed to move relatively to the guide rail by virtue of more than one rolling element of roller, the slider including a carriage made thereon with a second raceway groove lying in opposition to the first raceway groove to form a load race between them and further made therein with a return passage extending in parallel with the load race, end caps secured to forward and aft ends of the carriage and each made therein with a turnaround passage to connect the load race and the return passage with one another, and a plurality of rollers allowed to roll through a circulating circuit composed of the load race, return passage and a pair of the turnaround passages, the return passage being defined with a lengthwise sleeve inserted in a through-bore formed in the carriage;
wherein the sleeve has a lengthwise hole extending across overall length of the sleeve to provide the return passage, and further the sleeve is constituted with fore and aft circular ends, a pair of columns extending lengthwise between the fore and aft circular ends in opposition to each other to guide axially opposite ends of the roller, a pair of flexible columns lying between the columns and extending lengthwise between the fore- and aft circular ends in opposition to each other to make rolling contact with a rolling surface of the roller, lengthwise slits lying between the flexible columns and the columns, and second complementary ends made on the terminals of the fore and aft circular ends to make complementary fits with first complementary parts on ends of the end caps; and wherein the flexible column has raised lands and recessions which are arranged alternately in a lengthwise direction to make elastic deformation of the flexible column easier, the raised lands each having an outside curved surface spaced away from an inside circular surface of the through-bore in the carriage to form a clearance of a preselected interval lying between the carriage and the raised land of the flexible column, and the recessions each having a bottom surface spaced apart from the rolling wall surface of the return passage by a preselected thickness. |
