| 摘要 |
There is a parallel roller type roller bearing for an infinite rectilinear motion in which cylindrical rollers move in an infinite circulating passage. Two side plates are attached to both ends of the bearing unit, and a direction change passage communicated with the truck groove and formed in the same horizontal plane is formed in the side plate. A twisting passage is formed between the direction change passage and the truck groove. In the twisting passage, the cylindrical roller is gradually twisted until the central axis of the roller becomes vertical and is shifted from the truck groove into the unloaded region. In the cross section which is perpendicular to the slide direction of the bearing, the center of curvature of the twisting passage is located in the region contained by the extension line of the truck surface of the truck rail and the extension line of the end surface of the roller existing in the outside of the truck rail. The radius of curvature of the twisting passage is large at a location near the truck groove and is small at a location away from the truck groove. The twisting passage is formed such that the locus of the center of gravity of the roller, which moves in the twisting passage, draws cosine curve or single arc. Thus, the rollers can be stably and certainly twisted and shifted in the twisting passage. The slide resistance of the bearing is small and the bearing is miniaturized. |
