The present invention provides a transmission roller, a pin-teeth cycloid reducer with the same and a bearing. The transmission roller comprises a hollow roller which is made by spirally and closely winding a steel strip or a steel wire, and the length of the hollow roller remains unchanged when both ends thereof distributed along the axial direction are squeezed. When the hollow roller is subjected to external pressure, the ends thereof will not be easily damaged, and will not extend to the middle part during use, thus having a long service life.

The present disclosure provides a bearing assembly, a rotor assembly and a draught fan. The bearing assembly has a shaft sleeve and a shaft extending through the shaft sleeve. An inner wall of the shaft sleeve is provided with two grooves in a circumferential direction. The shaft is provided with two channels corresponding to the two grooves respectively. The channels and the grooves form two raceways. Multiple rolling bodies are disposed between the shaft and the shaft sleeve and movable in the raceways. The shaft sleeve has an outer diameter of 13 mm, and a portion of the shaft extending within the shaft sleeve has a diameter of 5 mm.

The present disclosure relates to a shaft adapted to be at least partially inserted into an opening of a shaft receiver. The shaft comprises a nominal shaft portion adapted to be at least partially inserted into the opening of the shaft receiver, followed by an intermediate shaft portion that in turn is followed by a guide shaft portion terminating the shaft. The shaft comprises a cross-section with a cross-sectional contour in a plane including the central axis, the cross-sectional contour comprising a nominal shaft portion contour of the nominal shaft portion, an intermediate shaft portion contour of the intermediate shaft portion and a guide shaft portion contour of the guide shaft portion. The cross-sectional contour comprises a radial direction being perpendicular to the central axis, wherein, as seen in the radial directio, the nominal shaft portion contour is located at a nominal radial distance from the central axis.

A modular wheel-hub bearing unit having an outer flanged hub for mounting the unit on an upright of a vehicle, provided externally with an assembly surface and internally with a mounting seat; and a bearing provided with an outer ring, two inner rings and two rows of rolling elements arranged between the outer ring and the two inner rings. The bearing being mounted inside the assembly seat independently of the outer flanged hub and having an outer diameter, the dimensions of which are related to the dimensions of an outer diameter of the assembly surface of the flanged hub by a first coefficient (α) according to the relation: D2=α*D1, where 0.80≤α≤0.95.

An assembly comprising: a core in the form of a toroid; and at least one washer overlying the core, the washer comprising a polymer, wherein the washer has an arcuate cross-section so as to have a shape complementary to the core.

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 having a bottom surface having an outer diameter smaller than the outer diameter of the fitting surface.

A bicycle bearing system comprising: an integrated cup, the integrated cup having an outer diameter; a plurality of rolling elements configured to abut and rotate against a first race groove located on an inner surface of the integrated cup; a second race groove configured to abut and rotate about the plurality of rolling elements, the second race groove located on an inner surface of the inner race, the inner race having an inner diameter; where the rolling elements do not have a separate outer race, but rather the inner surface of the integrated cup acts as the outer race to the rolling elements; and where the rolling elements, integrated cup and inner race are axially locked when assembled as a single cartridge unit due to the geometry of the rolling elements, first race groove and second race groove.

In an outer ring rotating rolling bearing (10), an inclined surface is formed on an outer peripheral surface of an inner ring (12) and decreasing in diameter toward an axially outer side, a seal member (20) includes an annular core metal (21) and an annular elastic member (22) fixed to the core metal (21), and an elastic member (22) includes a neck portion (28) extending from an inner peripheral edge portion (24a) of the core metal (21) toward a radially inner side and a seal lip (30) formed at a tip end portion of a neck portion (28) and brought into contact with the inclined surface (41) of the inner ring (12) with a tightening margin. Here, T2≥T1, where a width of the core metal (21) is T1 and a thickness of the neck portion (28) is T2. As a result, even in an environment where the outer ring is rotated at high speed and the seal member is subjected to external pressure (pressure fluctuation), the influence of centrifugal force generated on the seal lip can be suppressed, and the sealing performance of the seal member can be ensured.

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 bearing includes a plurality of rolling elements (26) spaced around a three-hundred and sixty degree circumferential extent of the bearing. An odd, non-singular number of high-points are positioned as near to evenly as possible about the circumferential extent of the bearing, the high-points defined by locations at which rolling elements with the largest diameters are positioned. An odd, non-singular number of low-points are positioned as near to evenly as possible about the circumferential extent of the bearing, the low-points defined by locations at which rolling elements having the smallest diameters are positioned. The odd, non-singular number of high-points is the same as the odd, non-singular number of low-points, and each low-point is positioned as near to evenly as possible between two adjacent high-points.