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, when considering: (i) a reference point which is the intersection point between the imaginary line extending from the generatrix of the raceway surface of the inner ring toward a grinding undercut, and the imaginary line extending from the generatrix of a large flange surface toward the grinding undercut; (ii) the undercut width A of the grinding undercut from the reference point to the large flange surface; and (iii) the width RC of a chamfer of each tapered roller in the direction along the generatrix of the large flange surface, the width RC is 0.7 mm or less and the relationship between A and RC is A<RC.

According to the embodiments of the present invention, the overall size reduction allows installation space to be advantageously secured, reduction in noise generated during operation improves the comfort of the driver, and the strength and stability of the connective structure between parts can be increased and power transmission can be more effective.

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).

Wettable structures that retain liquid layers are defined at surfaces of substrates. The wettable structures include grooves or ridges that are spaced apart by between 10 nm and 10 μm and can be defined in substrate or in a layer formed on a surface of the substrate. In typical examples, wettable structures are defined with hydrophobic materials or at hydrophobic surfaces and produce hydrophilic surfaces.

An input gear assembly in which the input gear is coupled to the input shaft via a pair of spaced-apart pilot regions of the input shaft. One of the pilot regions is disposed adjacent to one of the bearings used, with the pilot region formed in or on the input shaft itself and engaging a corresponding internal surface of the input gear. Another of the pilot regions is formed in the inner bearing raceway of another of the bearings used, with the pilot region formed as an elongate portion of the inner bearing raceway of the input shaft and engaging another corresponding internal surface of the input gear. For manufacturing simplicity, this additional pilot region and the remainder of the elongate inner bearing raceway have the same material properties, surface treatment, straightness, and cylindricity. This arrangement prevents tilting of the input gear with respect to the input shaft and bearing shaft, thereby enhancing performance.

Provided in one embodiment of the present invention is a bearing assembly comprising: an outer ring in which a hollow is formed and which has a protrusion protruding toward a central direction along the inner circumferential surface and a first ball contact portion and a second ball contact portion that are formed by the protrusion;

an inner ring having a third ball contact portion on the outer circumferential surface and forming a first track portion and a second track portion by being inserted into the hollow; and at least one bearing ball disposed between the outer ring and the inner ring to rotatably connect the outer ring and the inner ring, wherein the bearing balls are arranged in multiple rows in the first track portion and the second track portion and are configured to contact each of the ball contact portions.

A rolling bearing having an outer ring, an inner ring, and at least one row of rolling elements disposed between two raceways of the outer and inner rings. Furthermore, the raceway of the outer ring and/or the raceway of the inner ring at least partially provide a coating based on chromium nitride, the rolling elements at least partially include a coating based on carbon.

A hub for partially muscle-powered vehicles, including a hollow hub axle with a cylindrical inner through hole for the passage of a clamping axle, a hub shell rotatably supported relative to the hub axle by two hub bearings, a rotor rotatably supported relative to the hub axle, and a freewheel device with a hub-side freewheel component and a rotor-side freewheel component, each having axial engagement components for engagement with one another. The hub shell is rotatably supported relative to the hub axle in a rotor-side end region by a rotor-side hub bearing, and in an opposite end region of the hub shell by another hub bearing. The hub-side freewheel component is non-rotatably connected with the hub shell. The rotor-side freewheel component is non-rotatably connected with the rotor and is movable in the axial direction relative to the rotor and the hub shell between a freewheel position and an engagement position.

A segment bearing device for supporting a first bearing partner relative to a second bearing partner about a pivot axis (S) includes a plurality of rolling elements, a segment cage for receiving the rolling elements, and a partial shell, the partial shell providing a race for the rolling elements. At least one of the plurality of rolling elements is arranged as a mounting rolling element in a first partial circle (TK1) in an operating state of the segment bearing device, and is held in a second partial circle (TK2) in a mounted state of the segment bearing device. The common center point of the partial circles (TK1, TK2) is defined by a center of curvature of the segment cage, and the first partial circle (TK1) has a smaller diameter than the second partial circle (TK2).

A generatrix shape to which crowning is applied includes a first generatrix shape which is formed in a central portion in an axial direction of at least one of an outer ring raceway surface, an inner ring raceway surface, and a rolling surface of a roller and is composed of a straight line, a pair of second generatrix shapes which are formed from both ends in the axial direction toward the outside in the axial direction of the first generatrix shape and are composed of a single arc curve, and a pair of third generatrix shapes which are formed from both ends in the axial direction toward the outside in the axial direction of the second generatrix shape and are composed of a composite curve of a single arc curve and a logarithmic curve.