Devices and method include relatively moving elements having one or more bearing surfaces defining a gap between the elements into which a fluid is received. At least one of the bearing surfaces comprises a varying topography to provide pressurized volumes of the fluid in order to define a hydraulic bearing to support at least one of the elements during movement.

An oil supply structure which supplies lubricating oil to a portion to be lubricated in a casing, the oil supply structure comprises an opening portion provided on a wall portion of the casing which corresponds to a shaft end portion of a rotary shaft supported by a bearing in the casing, and an oil passage configured to provide communication from the opening portion to at least the bearing.

Systems and methods for producing hydrocarbons from a subterranean well include an electrical submersible pump assembly with a motor. The motor has a motor housing and a stator is located within the motor housing. The stator has a stator body with an interior cavity. A rotor assembly is located within the interior cavity of the stator. The rotor assembly includes a rotor shaft, a rotor member, and an intermediate rotor bearing assembly. The rotor member and the intermediate rotor bearing assembly circumscribe the rotor shaft. The rotor shaft extends along the central axis of the stator. A liner is located along an interior surface of the interior cavity, the liner being a thin walled member that is secured to the motor housing and seals the stator body from a wellbore fluid. The liner has a polygonal cross section.

A journal bearing includes: a carrier ring; a plurality of bearing pads disposed on a radially inner side of a lower half region of the carrier ring, and configured to support a rotor shaft from below; and a guide metal disposed in an upper half region of the carrier ring, in center with respect to an axial direction of the rotor shaft, so as to cover an upper region of an outer peripheral surface of the rotor shaft.

A first thrust bearing includes a first electromagnet and a first member. A second thrust bearing includes a second electromagnet and a second member. A magnetic force generated by the first electromagnet and the second electromagnet, and dynamic gas pressure generated by the first member and the second member due to rotation of a rotating shaft support an axial load of the rotating shaft.

A refrigeration apparatus includes a compressor connected to a refrigerant circuit, and a bearing monitor. The compressor includes a compression mechanism, an electric motor, a drive shaft, and a plain bearing that supports a journal portion of the drive shaft. The bearing monitor performs an abnormal-state operation to cope with poor lubrication on the plain bearing if an abnormal state condition is satisfied. The abnormal state condition is a condition indicating that a rate of change of current exceeds a first reference value. The rate of change of current is an amount of change in a driving current usable to drive the compressor per unit time. The journal portion of the drive shaft has a surface roughness of at least 0.05 μm.

A bearing assembly having an inner race, an outer race, and a plurality of rollers positioned between the inner race and the outer race. A pad is attached to the inner race and a bed is attached to the outer race. A timing mechanism is slidably mounted to the pad and the bed. Preferably the pad and bed are made of plastic and the inner race is embedded within the pad and the outer race is embedded within the bed.