A bearing device includes a rotary part which is configured to be rotatable about a rotational axis and has a rotary surface intersecting the rotational axis, and a stationary part which has a stationary surface facing the rotary surface. One of the rotary surface or the stationary surface includes a bearing surface part for forming a bearing oil film. The rotary surface includes a first inner circumferential region, and a first outer circumferential region facing the stationary surface on a radially outer side of the bearing surface part and having higher oleophobicity than the first inner circumferential region.

A mechanical component, a mechanism module, a movement, and a timepiece superior in lubricating oil retaining performance are to be provided. A mechanical component includes: a first component having a first surface region; a second component having a second surface region on which the first surface region can slide; and an oil retaining film formed on at least one of the first surface region and the second surface region and more lipophilic than the region.

A bearing device includes a rotary part which is configured to be rotatable about a rotational axis and has a rotary surface intersecting the rotational axis, and a stationary part which has a stationary surface facing the rotary surface. One of the rotary surface or the stationary surface includes a bearing surface part for forming a bearing oil film. The rotary surface includes a first inner circumferential region, and a first outer circumferential region facing the stationary surface on a radially outer side of the bearing surface part and having higher oleophobicity than the first inner circumferential region.

A fluid dynamic bearing device prevents an oleophobic agent from wetting and spreading to a tapered seal portion, including lubricating oil C filled in a condition in which the oil is separated sandwiching a separator portion 240 holding a gas layer arranged between two conical bearing members 201, and two primary tapered seal portions 230 each connecting to one of both ends along an axial direction of the separator portion 240, wherein width in a radial direction of the two primary tapered seal portion 230 decreases as each approaches toward the two conical bearing members 201, a gas-liquid interface of the lubricating oil C is located each of the two primary tapered seal portions 230, an oleophobic agent blocking portion 250 is arranged at each of both ends in an axial direction of the separator portion 240, a separator central portion 244 is arranged between the oleophobic agent blocking portions 250 of the separator portions 240, and an oleophobic coating is formed at least at the separator central portion 244 of the separator portion 240.

A fluid dynamic bearing device prevents an oleophobic agent from wetting and spreading to a tapered seal portion, including lubricating oil C filled in a condition in which the oil is separated sandwiching a separator portion 240 holding a gas layer arranged between two conical bearing members 201, and two primary tapered seal portions 230 each connecting to one of both ends along an axial direction of the separator portion 240, wherein width in a radial direction of the two primary tapered seal portion 230 decreases as each approaches toward the two conical bearing members 201, a gas-liquid interface of the lubricating oil C is located each of the two primary tapered seal portions 230, an oleophobic agent blocking portion 250 is arranged at each of both ends in an axial direction of the separator portion 240, a separator central portion 244 is arranged between the oleophobic agent blocking portions 250 of the separator portions 240, and an oleophobic coating is formed at least at the separator central portion 244 of the separator portion 240.

Provided is a rolling bearing, in particular for a wind turbine, including an inner race, an outer race, a plurality of rolling elements arranged between the inner race and the outer race, and lubricant for lubricating the rolling bearing, wherein the inner race and the outer race each have a bearing surface with a contact zone in contact with the rolling elements, the bearing surface of at least one of the inner race and the outer race has a portion having a lipophobic surface for repelling the lubricant. The suggested rolling bearing has the advantage that the lubricant in the bearing does not stick to the portion, where it is useless for lubricating the bearing. Therefore, the rolling bearing can have a better lubrication, since the lubricant is directed towards the contact zone, where contact between the races and the rolling elements takes place.

A pivot assembly bearing device includes a shaft having an outer peripheral surface and a rolling bearing fixed to the shaft. An annular sealing surface axially overlapping with at least a part of an end surface of the rolling bearing is provided on an axially outer side of the rolling bearing. An oil-repellent film is annularly formed on at least one of the sealing surface and a part of the outer peripheral surface of the shaft located axially outward from the rolling bearing.

In a thrust needle roller bearing, even in an environment where an amount of lubricating oil is small, the amount of lubricating oil is held and seizure is prevented. The thrust needle roller bearing includes a plurality of needle rollers, a bearing ring (31) having an annular raceway surface (31a) on which the needle rollers roll, and a cage that rollably holds the needle rollers, in which an oil repellent film (41a) is formed by oil repellent treatment on a portion of the raceway surface (31a) other than a portion in contact with the needle rollers.

A pivot assembly bearing device includes a shaft having an outer peripheral surface and a rolling bearing fixed to the shaft. An annular sealing surface axially overlapping with at least a part of an end surface of the rolling bearing is provided on an axially outer side of the rolling bearing. An oil-repellent film is annularly formed on at least one of the sealing surface and a part of the outer peripheral surface of the shaft located axially outward from the rolling bearing.

A retainerless rolling element bearing (20) is disclosed as including an inner raceway (22), an outer raceway (24), a plurality of first type of rolling elements (26) and a plurality of second type of rolling elements (28) alternately arranged adjacent to each other and between the inner raceway and the outer raceway, a surface of the first type of rolling elements having a higher contact angle, a lower contact angle hysteresis and a smaller magnitude of surface energy than a surface of the second type of rolling elements.