Abstract: An inner race of a first rolling bearing is fixed to a shaft, and an outer race thereof is fixed to an inner race of a second rolling bearing. In the first bearing, the outer race and rolling elements contact each other on the side of a center of the rolling elements closer to one end side in an axial direction, and the inner race and the rolling elements contact each other on the side of the center of the rolling elements closer to the other end side in the axial direction. In the second bearing, an outer race and rolling elements contact each other on the side of a center of the rolling elements closer to the one end side, and the inner race and the rolling elements contact each other on the side of the center of the rolling elements closer to the other end side.

Abstract: A bearing device has a sleeve that encircles a shaft, and two side-by-side roller bearings rotatably support the sleeve coaxially on the shaft. A spacer portion protrudes radially inwardly from the sleeve and extends between the two roller bearings. The sleeve axially overlaps a minor portion of one roller bearing but does not overlap a race surface thereof, and the sleeve axially overlaps a major portion of the other roller bearing including a race surface thereof.

Abstract: A bearing unit has four rolling bearings adjacently disposed in an axial direction, each rolling bearing including an inner race, and outer race, and rolling elements interposed between the inner and outer races. A shaft is fitted to the inner races, and a sleeve has a fitting hole into which is fitted the outer races. The inner races or the outer races are brought into contract with each other in the axial direction to preload the rolling bearings. The inner races or the outer races of the rolling bearings at both axial ends, which are brought into contact with the inner races or the outer races of adjacent rolling bearings, are fixed to the sleeve, and the outer races of the central two rolling bearings form a radial gap between confronting surfaces of the sleeve and the outer races or between confronting surfaces of the shaft and the inner surfaces.