An upper raceway ring has an inward flange portion. A lower raceway ring has an outward flange portion. An upper case has an outwardly projecting piece projecting in the radially outward direction toward an end surface of the inward flange portion from a surface facing the end surface. A lower case has an inwardly projecting piece projecting in the radially inward direction toward an end surface of the outward flange portion from a surface facing the end surface. The end surface of the upper raceway ring comes into contact with the outwardly projecting piece of the upper case, to allow the upper raceway ring to be held by the upper case. The end surface of the lower raceway ring comes into contact with the inwardly projecting piece of the lower case, to allow the lower raceway ring to be held by the lower case.

Provided is a friction design method capable of estimating sliding friction generated between mutual sliding surfaces of two sliding members lubricated with lubricant with high precision. The friction design method sets a friction coefficient μ in a sliding surface model corresponding to mutual sliding surfaces of two sliding members (2 and 3) lubricated with lubricant (step S1), and, based on a correlation between the friction coefficient μ and an oil film parameter (Λ(Rk) or Λ(Rk+Rpk)) calculated using a core portion level difference (Rk) or a sum of the core portion level difference (Rk) and reduced peak height (Rpk) as a parameter representing surface roughness in the sliding surface model (step S2), sets a target value for surface roughness of the sliding surfaces required to be controlled as a product (steps S3 to S6).

A low clearance, high load capacity roller bearing that includes a cylindrical outer race with a set of non-helical grooves formed on its inside surface that mesh with teeth formed on the outside surface of a plurality of rotating rollers longitudinally and axially aligned inside the outer race. Located inside the rollers are two cylindrical inner race pieces each with non-helical outer grooves configured to mesh with the teeth on the rollers. The rollers are longitudinally aligned and evenly spaced apart inside the outer race and outside the inner race assembly by two retainer plates. The two inner race pieces are separated by a uniform circular gap in which a circular shim is disposed. Different lengths of inner race pieces may be used to create different gap widths needed to reduce the clearance or to pre-load the bearing. Shims with different widths slightly larger or smaller than the gap are placed in the gap.

In a bearing for vertical axis windmill configured to rotatably support a vertical axis of a vertical axis windmill, the bearing includes a ball (7), a diameter of the ball and a curvature of a rolling groove of the bearing are set to satisfy a predetermined starting torque and a load rating. For example, the curvature of the rolling groove of the bearing is 54% or more and 100% or less, and the diameter of the ball has a ratio of 20% or less with respect to a vertical shaft (2).

The bearing provides an inner race, an outer race and a wear race that is made of synthetic material and fastened to one of the races. The wear race is overmolded on at least one face of the race. The face includes at least one retention means that is covered with the synthetic material of the wear race and shaped to allow both the axial retention and the angular retention of the wear race relative to the race by shape complementarity with the wear race.

A difference between a maximum value and a minimum value of arithmetic mean roughness Ra of an annular surface region in contact with a larger flange surface, in a larger end face of the tapered roller, is not greater than 0.02 μm. A value of a ratio R/R.sub.BASE is not smaller than 0.75 and not greater than 0.87 where R represents a set radius of curvature of the larger end face of the tapered roller and R.sub.BASE represents a distance from a point which is an apex of a cone angle of the tapered roller to the larger flange surface of the inner ring. A ratio R.sub.process/R is not lower than 0.5 where R.sub.process represents an actual radius of curvature after grinding of the larger end face of the tapered roller and R represents a set radius of curvature.

A rolling bearing, in particular a center-free large rolling bearing, having two concentric ball races with one ball race comprising a groove open toward the other ball race and the other ball race comprising a scraper ring engaging into the groove, wherein the scraper ring is supported at the groove in the axial direction of the rolling bearing by at least two axial bearings arranged at oppositely disposed scraper ring front sides and wherein the scraper ring is supported in the radial direction by at least one radial bearing which is arranged on a scraper ring jacket surface. The scraper ring is supported in the axial direction at the groove by a third axial bearing, wherein two axial bearings are arranged at the same side of the scraper ring at separate raceways offset from one another in the axial direction of the rolling bearing.

A bearing assembly for a turbocharger includes a turbine wheel-side ball bearing at a first axial end of a tubular body, a compressor impeller-side ball bearing at a second axial end of the tubular body, and a bearing housing. The bearing housing includes a first opposed wall opposed to an axially outer side of an outer race of the turbine wheel-side ball bearing, and a second opposed wall opposed to an axially outer side of an outer race of the compressor impeller-side ball bearing. The outer race of the turbine wheel-side ball bearing and the outer race of the compressor impeller-side ball bearing have axially outer end surfaces which are axially outwardly displaced from respective axial end surfaces of the tubular body so that oil films are present between the respective outer races and the corresponding opposed walls.

A small-sized finite linear motion guide unit is provided in which there is provided a rack-and-pinion arrangement to prevent any discrepancy between retainer plates to make sure of relative sliding movement of guideways. A rack is composed of teeth portions and a pair of connecting bars to fasten the teeth thereon. The connecting bars are different in widthwise length to form asymmetrical shapes. The grooves for a rack made on the guideway includes a middle groove to get the rack to mate with the pinion, and sidewise grooves lying on both sides of the middle groove and having the connecting bars different in widthwise length to make an asymmetric shape.

A bearing ring for a rolling-element bearing including an axially extending outer surface, two radially extending side surfaces, an inner surface configured to at least partially contact a rolling element and at least one radially extending recess in the inner surface that is configured to work together with a lifting tool to allow the bearing ring to be lifted by the lifting tool. Also a method of lifting a bearing ring having such a recess.