A deep groove ball bearing having an inner ring, an outer ring and a plurality of rolling elements set between the inner and outer rings. The rolling elements have a diameter D.sub.w ≤ 0.5H.sub.1 , up to D.sub.w ≤ 0.35H.sub.1 . H.sub.1 is the radial dimension of the bearing in the sense of thickness and is numerically equal to half of the difference between the outer diameter and inner diameter of the bearing. By using sufficient number but smaller size of rolling elements, the deep groove ball bearing can obtain enhanced axial and radial rigidity, which is not only conducive to reducing creep and wear of bearing mating surfaces, avoiding early failure of bearings, but also improving the rotational accuracy of equipment, avoiding vibration, noise and other problems caused by insufficient bearing rigidity, fully meeting the comprehensive needs of rotating equipment for bearing performance.

A rolling bearing includes an outer ring, an inner ring, a plurality of rolling bodies, and a seal member. An outer peripheral portion of the seal member is fixed by a retaining ring to a groove portion formed on an inner peripheral surface of the outer ring and an inner peripheral portion of the seal member is elastically deformable. The seal member includes an inclined portion. 1≤Ts/Sct≤10 is satisfied when Ts is a circumferential gap of the retaining ring at a time when the seal member and the retaining ring are attached to the groove portion of the outer ring and Sct is an axial thickness of a part of the seal member in contact with the retaining ring.

A rolling bearing includes an outer ring, an inner ring, a plurality of rolling bodies, and a seal member. An outer peripheral portion of the seal member is fixed by a retaining ring to a groove portion formed on an inner peripheral surface of the outer ring and an inner peripheral portion of the seal member is elastically deformable. The seal member includes an inclined portion. The seal member satisfies 0.25≤Skn/Skt≤2.5 when Skn is a radial length from an inclination start part of the inclined portion on an inside in an axial direction to an outermost diameter position of a part of contact of the seal member with an outer peripheral surface of the inner ring and Skt is a thickness of the inclined portion in a direction perpendicular to an inclination direction.

Disclosed is a bearing assembly for an electric motor for a vehicle, providing at least one main bearing configured to support a rotational element of the electric motor, and a sacrificial bearing. The main bearing includes at least one inner ring, at least one outer ring and at least one plurality of rolling elements. The sacrificial bearing provides an outer ring, an inner ring, and a plurality of rolling elements disposed between the outer ring and the inner ring. A value of a breakdown voltage for the sacrificial bearing is less than a value of the breakdown voltage for the at least one main bearing.

Lubricating oil has a kinematic viscosity in a range of 1 mm.sup.2/S to 7 mm.sup.2/S at 40° C., has a mass average molecular weight in a range of 150 to 400, and contains 0.5% by mass or more of a high molecular weight component. The high molecular weight component has a mass molecular weight of greater than or equal to 500. A crankshaft serving as a shaft part of a compression element includes a main shaft that includes a sliding surface. In a case where the sliding surface is a single sliding surface, a length of the single sliding surface in an axial direction is a single sliding length L, whereas in a case where the sliding surface is divided into a plurality of sliding surfaces, a length of one of the sliding surfaces in the axial direction, the one sliding surface having a least length in the axial direction among the plurality of sliding surfaces, is the single sliding length L, and a ratio L/D of the single sliding length L to an external diameter D of the main shaft is less than or equal to 2.0.

A rolling bearing including an outer ring, an inner ring, rolling elements interposed between the outer ring and the inner ring and a cage for retaining the rolling elements and provided with radial seats or pockets for housing the rolling elements. The cage is guided supportingly on the outer ring with which a first clearance (G1) is defined, while between the pockets and the rolling elements there is a second clearance (G2) such that they have a relative ratio of between about 0.4 and 1. The rolling elements may be balls and the pockets may be formed by radial through-holes, which are circular or square in shape.

A bearing unit having a radially outer ring, a radially inner ring, a row of rolling elements interposed between the outer ring and the inner ring, a shaped sealing screen interposed between the inner ring and the outer ring and stably inserted inside a first seat of the outer ring, and a snap ring stably inserted inside a second seat of the radially outer ring and interacting with the shaped screen so as to lock it in the first seat.

A support ring assembly for a railway axle having a support ring configured to be inserted between a rolling bearing and a collar of the railway axle, the support ring having an annular seat, a surface of a radially inner side wall fitted with a radial clearance over the collar and an end wall that abuts against the collar, an annular insert fitted into the seat by means of an annular shield and having an elastomeric annular element having at least two annular protuberances that engage with the collar, the annular element configured to engage with the collar so as to occupy the radial clearance.

A rolling bearing includes an outer ring as a fixed ring, an inner ring as a rotary ring, and rolling elements disposed between the outer ring and the inner ring. The outer ring includes, on the radially opposite side of its raceway surface, a fitting surface fitted to a mating member, two annular grooves in which elastic members are fitted, and a recess adjacent to the annular grooves, and the recess has a bottom surface having an outer diameter smaller than the outer diameter of the fitting surface.

A tapered roller bearing includes an inner ring having a tapered raceway surface and a large-collar surface on a large-diameter side of the raceway surface, and tapered rollers. Each of the rollers has a large end surface guided by the large-collar surface. When R represents a set curvature radius of the large end surface and R.sub.BASE represents a base curvature radius from a vertex of a cone angle of each of the tapered rollers to the large-collar surface, the base curvature radius R.sub.BASE is 100 mm or less, and a ratio R/R.sub.BASE of the set curvature radius R to the base curvature radius R.sub.BASE is set to 0.90 or less. When R.sub.ACTUAL represents an actual curvature radius of the large end surface of each of the tapered rollers, a ratio R.sub.ACTUAL/R of the actual curvature radius R.sub.ACTUAL to the set curvature radius R exceeds 0.5.