A thrust washer may include a metallic substrate layer having an axial substrate face. The thrust washer may also include a polymer layer on the axial substrate face. The polymer layer may have an axial polymer face opposed to the axial substrate face. The axial polymer face may be profiled and may have at least one oil distribution groove. At least one of the substrate layer and the polymer layer may be a machined layer having a thickness that may vary in correspondence with the at least one distribution groove.

A sintered metal bearing is formed through sintering of a compact obtained through compression molding of raw-material powder. The sintered metal bearing includes chamfered portions that are respectively formed at least along outer rims of both end surfaces of the sintered metal bearing, and a dynamic pressure generating portion formed on an inner peripheral surface of the sintered metal bearing by sizing. An axial dimension of each of the chamfered portions is set larger than a radial dimension of the each of the chamfered portions, and a difference in axial dimension between the chamfered portions on one end side and another end side in an axial direction of the sintered metal bearing is set larger than a difference in radial dimension between the chamfered portions on the one end side and the another end side in the axial direction.

By randomly arranging dimples provided on a sealing face, a sliding characteristic is improved in a wide range of a bearing characteristic number on the sealing face. A pair of sliding parts in which a plurality of dimples is arranged on at least one of sealing faces that relatively slide on each other is characterized in that each of the plurality of dimples is provided independently from the other dimples, and arranged in such a manner that the plurality of dimples having different opening diameters is randomly distributed.

A bearing structure for an X-ray tube is provided that includes a journal bearing shaft with a radially protruding thrust bearing encased within a bearing sleeve, one of which rotates relative to the other. The stationary component, e.g., the journal bearing and/or the thrust bearing includes at least one vent groove formed therein that improves the ability of the journal bearing structure to enable gases trapped by the liquid metal within the bearing assembly to escape through the vent groove to the exterior of the X-ray tube. By adding a strategically located channel or vent groove of sufficient size in at least one of the journal bearing or the thrust bearing, the pressures resisted by the seal created between the liquid metal and the vent groove(s) in the bearing components is significantly reduced, allowing escape of the gases to avoid detrimental effects to the operation of the X-ray tube, while maintaining the load carrying capacity of the bearing assembly.

Dynamic pressure bearing (10), including: a green compact (10′), as a base material, of raw material powder including metal powder capable of forming an oxide coating; and dynamic pressure generating portions (A1 and A2) formed through die molding on an inner peripheral surface (8a) forming a radial bearing gap with an outer peripheral surface (2a1) of a shaft to be supported, that is, a shaft member (2). An oxide coating (11) is formed between particles of the metal powder by subjecting the green compact (10′) to steam treatment, and the dynamic pressure bearing (10) has a radial crushing strength of 150 MPa or more.

A ratio W1/W2 of a circumferential width W1 of each of inclined hill portions G2 of a radial dynamic pressure generating portion G and a circumferential width W2 of each of inclined groove portions G3 is 1.2 or larger. And when an inner diameter of a bearing member is D, the circumferential width W2 of each of the inclined groove portions satisfies 0.2D≦W2≦0.4D.

A thrust washer is provided with a ring-shaped portion that surrounds an insertion hole, the thrust washer is provided with a sliding surface and an oil groove configured to allow lubricating oil to flow in, the oil groove is provided with an opening portion configured to allow the lubricating oil to flow in from the insertion hole side in an inner peripheral end side, an outer periphery end side of the ring-shaped portion of at least one of the oil groove is provided with an oil stop wall which is configured to suppress flow of the lubricating oil toward an outer periphery side of the ring-shaped portion, and a sliding area ratio of each of the sliding surfaces to a projection plane in plan view of the ring-shaped portion is provided within a range of from 60% to 85%

A washer assembly and a hydrodynamic torque converter comprising the washer assembly is provided. The washer assembly comprises a washer and a plate; the washer is annular and comprises a washer body and two or more positioning clamps protruding radially inward from an inner periphery of the washer body, at least one side of the positioning clamp in a circumferential direction having a positioning protrusion protruding; the plate is annular, an inner periphery portion of the plate being provided with two or more positioning notches; an edge of at least one side of the positioning notch in the circumferential direction being provided with a positioning groove; and the washer is mounted to one end face of the plate. The washer assembly saves the internal space of the torque converter and saves the material cost of the washer.

A liquid guiding structure for a fluid dynamic pressure bearing, comprising: a fluid dynamic pressure bearing having an inner recess chamber and a liquid guiding trench which is formed between two sides of the inner recess chamber so as to form a circular close liquid guiding structure; wherein the liquid guiding trench includes at least two small V shape paths and at least one large V shape path; the large V shape path is larger than the small V shape paths and is located between the at least two small V shape paths. First angles at tip ends of the at least two small V shape paths are equal. A second angle between connections of the small V shape path and a respective large V shape path is larger than the first angle at tip ends of the at least two small V shape paths.

A sliding component includes a plurality of dynamic pressure generation mechanisms circumferentially arranged on a sliding surface of the sliding component. Each dynamic pressure generation mechanism includes an introduction groove portion communicating with a sealing target fluid side through an opening portion of the introduction groove portion and a dynamic pressure generation groove portion communicating with the introduction groove portion and extending in a circumferential direction in which the sliding component is relatively rotated with respect to a mating sliding component. The introduction groove portion is partially defined by a boundary wall positioned between the introduction groove portion and the dynamic pressure generation groove portion. The boundary wall has an inclined surface where at least a portion of the boundary wall positioned on a side of the opening portion extends toward the sealing target fluid side and inclined to a side of the dynamic pressure generation groove portion.