A roller bearing includes an inner race ring, an outer race ring, and a roller arranged between and in contact with the inner and outer rings. The bearing has a flange on the inner race ring at one axial end, and a flange on the outer race ring at an opposite axial end. At least one of the flanges, or an end of the roller, has a profile including a principal segment with a reference point C defining a contact location between the roller and the flange, the principal segment having a continuously changing radius of curvature, on both sides of reference point C, that decreases as a distance from the reference point C increases.

A tapered roller bearing is provided in which, in order to prevent a sharp rise in temperature and rotate the bearing smoothly even when the bearing is used under sever lubrication conditions, a grinding undercut has an undercut width A of 0.5 mm or less from a reference point to a large flange surface, the reference point being the intersection point of the imaginary line extending from the generatrix of the raceway surface of the inner ring toward the grinding undercut, and the imaginary line extending from the generatrix of the large flange surface toward the grinding undercut.

A caster 1 includes a wheel 10, a fork 20, a second member 20, and a rolling bearing 40. The rolling bearing includes an outer ring 40A, an inner ring 40B, and a plurality of rolling elements. The outer ring 40A includes a first outer ring 41 and a second outer ring 42. The inner ring 40B includes a first inner ring 43 and a second inner ring 44.

A sheet metal strip configured for use as an inner or outer raceway of a rolling-element bearing, and a method of forming the raceway by punching and/or laser cutting a strip of material from a metal sheet, bending the sheet into a ring and welding the ends of the strip together, and mounting the strip on a circular inner or outer surface to form an outer or inner raceway.

An outer-ring lubrication groove pattern formed in an outer-race raceway surface and an inner-race lubrication groove pattern formed in an inner-race raceway surface of a wave generator bearing of a strain wave gearing device are patterns in which linear lubrication grooves having very small widths and depths of several micrometers or less are arranged at fine pitches of several micrometers or less. The inner-race lubrication groove pattern includes a second groove pattern formed in long-axis-side inner-race raceway surface portions to hold the lubricant, and a first groove pattern formed in short-axis-side inner-race raceway surface portions to hold the lubricant and guide the lubricant to the second groove pattern. This configuration improves the contact state between balls and the inner-race and outer-race raceway surfaces of the wave generator bearing, thus reducing the coefficient of friction therebetween.

According to the method of the invention, a lubricant is supplied incrementally to a rotary bearing while the bearing is in operation rotating at a rotational speed. The lubricant is supplied in consecutive steps so that at each step a portion of a prescribed amount of lubricant is supplied, followed each time by an ultrasound measurement. A first ultrasound measurement is performed before the first supply step, and starting from the second supply step, each measurement result is compared at least to the previous result, in order to evaluate the bearing condition and decide on that basis whether to continue the sequence or not. Stopping the sequence is decided when the lubrication of the bearing is assessed as successful, a lubrication failure or over-lubrication. The invention is equally related to a system for lubricating one or more bearings, applying the method of the invention to each of said bearings.

A motor vehicle drive wheel assembly comprising a fixed subassembly comprising two outer raceways; and, a rotating subassembly comprising a first inner race, a second inner race and two rows of balls arranged in two pitch planes PP1 and PP2. The second inner bearing race has an outer diameter, measured in a section plane perpendicular to the axis of rotation and located between the first pitch plane and the second pitch plane, at a measurement distance DM of the first pitch plane, which is greater than a given threshold value VS.

A multi-row bearing assembly includes first and second rolling-element bearings having first and second bearing rings and first and second rows of rolling elements therebetween, respectively, each ring having exactly one guide flange. An intermediate space exists between the first and second rows of rolling elements, and a first side of each row of rolling elements faces the intermediate space and a second side of each row of the rolling elements is remote from the intermediate space. The guide flanges of the first and third bearing rings guide the first sides of the rolling elements, and the guide flanges of the second and fourth bearing rings guide the second sides of the rolling elements.

A bearing assembly comprises an outer ring and an inner ring radially inward of the outer ring and cooperating therewith to form a roller volume. The inner ring has opposed faces including slots extending axially and circumferentially spaced. The slots extends axially to openings into the opposed axial faces and communicate with partial circumferential slots in the inner circumferential surface and in fluid communication with the roller volume through passages in the inner ring. A first plurality of the axial slots has a radial depth increasing from a first of the axial faces to the respective partial circumferential slot. A second plurality of the axial slots has a radial depth increasing from the second of the axial faces to the respective partial circumferential slot. Bearing elements are in the roller volume rollingly disposed against the outer ring and the inner ring.

Wheel hubs for a motor-vehicle wheel hub assemblies provided with a bearing unit in turn which include at least one row of rolling bodies, the wheel hub being provided with at least two sheet-metal elements which are rigidly joined together, wherein a first sheet-metal element forms a raceway for the at least one row of rolling bodies.