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 sliding member includes a back-metal layer including an Fe alloy and a sliding layer including a copper alloy including 0.5 to 12 mass % of Sn and the balance of Cu and inevitable impurities. The sliding layer has a cross-sectional structure perpendicular to a sliding surface of the sliding layer. The cross-sectional structure includes first copper alloy grains that are in contact with a bonding surface of the back-metal layer and second copper alloy grains that are not in contact with the bonding surface. The first copper alloy grains has an average grain size D1 and the second copper alloy grains has an average grain size D2. D1 and D2 satisfy the following relations: D1 is 30 to 80 μm; and D1/D2=0.1 to 0.3.

A sliding member includes an overlay layer made of a resin on a side of a sliding surface of a bearing alloy layer. When a valley void volume Vvv (μm.sup.3/μm.sup.2) in the sliding surface of the overlay layer is defined as Vv1, Vv1 is in a range of 0.015≤Vv1≤0.200.

A bearing member 1 is provided with a coating layer 3 on an inner circumferential surface of a shaft hole 1A into which a shaft body 2 is to be fitted. The coating layer 3 is composed of a metal base material 3A and a heat conductive material 3B that is dispersed in the base material 3A and that has a thermal conductivity relatively higher than that of the base material 3A. The heat conductive material 3B has lengths Lb and Lc in directions B and C along a surface of the coating layer 3, longer than a length La in a thickness direction A of the coating layer 3, whereby thermal conductive characteristics in the directions B and C along the inner circumferential surface of the shaft hole 1A are enhanced. Thus, heat dissipation is improved, whereby temperature rise due to sliding contact with the shaft body 2 is suppressed, and seizure resistance is improved.

The steel material for a carburized bearing part according to the present invention contains, by mass %, C: 0.25 to 0.45%, Si: 0.15 to 0.45%, Mn: 0.40 to 1.50%, P: 0.015% or less, S: 0.005% or less, Cr: 0.60 to 2.00%, Mo: 0.10 to 0.35%, V: 0.20 to 0.40%, Al: 0.005 to 0.100%, Ca: 0.0002 to 0.0010%, N: 0.0300% or less and O: 0.0015% or less, with the balance being Fe and impurities, and satisfies Formulae (1) to (3).
1.20<0.4Cr+0.4Mo+4.5V<2.75  (1)
A1/A2>0.50  (2)
2.7C+0.4Si+Mn+0.45Ni+0.8Cr+Mo+V>2.55  (3)
Formula (2) shows an area fraction of sulfides containing Ca in an amount of 1 mol % or more among sulfides having an equivalent circular diameter of 1 μm or more.

A sliding member includes a back-metal layer including an Fe alloy and a sliding layer including a copper alloy including 0.5 to 12 mass % of Sn and the balance of Cu and inevitable impurities. A cross-sectional structure of the sliding layer includes first copper alloy grains in contact with a bonding surface and second copper alloy grains not in contact with the bonding surface. The first and second grains have an average grain size D1 and D2 respectively. D1 is 30 to 80 μm; and D1/D2=0.1 to 0.3. In the cross-sectional structure, the second grains includes third grains that includes internal grains therein that are not in contact with a grain boundary of the third grains. A total area S1 of the third grains and a total area of the second copper alloy grains S2 satisfy: S0/S2=0.25 to 0.80.

An electroconductive roll includes a core member, a rubber base material disposed around the core member, and a surface layer disposed around the rubber base material. The surface area of the surface layer per unit projected area is equal to or greater than 1.255, and is equal to or less than 6.635.

Various teachings herein may be used to make a bearing bush for a rotating shaft, wherein a wall of the bearing bush has a wall thickness which amounts to less than 10% of the diameter of the bearing bush. In the axial direction, the bearing bush is made from a plurality of layers connected with a material bond. Each layer has a layer thickness between 10 μm and 200 μm and the wall has closed cavities which are filled with a powder.

A bearing monitoring apparatus includes a rolling bearing. The rolling bearing includes an outer ring and an inner ring disposed coaxially with the outer ring, the inner ring being on an inner peripheral side of the outer ring. The rolling bearing includes multiple rolling elements disposed between the outer ring and the inner ring. The rolling bearing includes a strain gauge configured to detect strain of the outer ring or the inner ring, the strain gauge including at least two resistors, and the resistors being arranged in a same direction as an arrangement direction of the rolling elements so as to correspond to spacing between rolling elements that are next to each other. The bearing monitoring apparatus includes a waveform generator configured to generate a first distorted waveform based on an output of one resistor and to generate a second distorted waveform based on an output of another resistor. The bearing monitoring apparatus includes a subtracting unit configured to subtract the second distorted waveform from the first distorted waveform to generate a differential waveform. The bearing monitoring apparatus includes a comparator configured to compare the differential waveform against a reference value to detect a wear state of the rolling bearing.

It is possible to provide an iron-based sintered sliding material excellent in the sliding performance. Provided is an iron-based sintered sliding material including, a base containing, by mass, 3 to 15% of S, 0.2 to 6% in a total amount of at least one selected from the group consisting of Cr, Ca, V, Ti, and Mg, and a remainder of Fe and inevitable impurities, sulfide particles containing at least one selected from the group consisting of Cr, Ca, V, Ti, and Mg being dispersed in the base, and pores.