Patent ID: 6880975

Claim:
A linear motion guide unit comprising; a track rail having a pair of side walls extending lengthwise in parallel with one another, the side walls being made on their sidewise opposing inside surfaces with first raceway grooves, one to each inside surface; a slider movable lengthwise along the track rail in a guiding way made open between the side walls of the track rail, the slider being made thereon with second raceway grooves in opposition to the first raceway grooves; and rolling elements running through a load raceway defined between the confronting first and second raceway grooves; wherein a retainer band is installed in the slider to keep the rolling elements in the slider, while a relief flute is cut deep in the first raceway grooves in a way extending lengthwise along the first raceway groove, and wherein the retainer band on the slider fits in the relief flute for relative movement as the slider travels relatively to the track rail, wherein the relief flute has an upper tapered flank and a lower tapered flank such that a slant angle of the upper tapered flank is more than a slant angle of the lower tapered flank.