To provide a fluid dynamic bearing lubricating oil base oil which is within a suitable 40° C. and 100° C. kinematic viscosity range capable of achieving both energy saving and high bearing rigidity, and is excellent in viscosity index, heat resistance (evaporation resistance), and low temperature fluidity. Provided is a fluid dynamic bearing lubricating oil base oil containing an isophthalic acid diester compound represented by the following general formula (1)

##STR00001## wherein R1 and R2 are the same or different and each represent a linear alkyl group having 6 to 10 carbon atoms.

Provided is a fluid film bearing, for a rotor hub in a wind turbine, including a first and second part rotatably connected to each other, wherein the first part forms a first annular sliding surface that extends in the circumferential direction of the bearing along the first part, wherein the second part includes a support structure and first pads distributed along the circumference of the support structure, wherein a respective pad sliding surface of each of the first pads or of a first subgroup of the first pads supports the first annular sliding surface, wherein each first pad includes a mounting section that is mounted to a backside of the support structure, a contact section that is either forming the respective pad sliding surface or carrying a coating that forms the respective pad sliding surface and a connecting section that connects the contact section with the mounting section.

A crankshaft bearing structure is provided capable of properly lubricating a thrust bearing even when low-viscosity oil is used in an engine. The crankshaft bearing structure includes a crankshaft, a cylinder block, plural journal bearings, and thrust bearings. Each of the plural journal bearings is annularly attached to a respective one of plural crank journals when the crankshaft is rotating. The thrust bearings are attached to a shaft support section, which supports the crank journal, in the cylinder block, to restrict movement of the crankshaft in a direction along an axis. The upper journal bearing annularly attached to the crank journal has a circumferential groove provided in an inner circumferential surface, connected to an oil hole, and extending in a circumferential direction.

Solar trackers that may be advantageously employed on sloped and/or variable terrain to rotate solar panels to track motion of the sun across the sky include bearing assemblies and other mechanical features configured to address mechanical challenges posed by the sloped and/or variable terrain that might otherwise prevent or complicate use of solar trackers on such terrain.

In order to effect a seal a porous material which comprises one side of two opposing surfaces is used to restrict and evenly distribute externally pressurized gas, liquid, steam, etc. between the two surfaces, exerting a force which is opposite the forces from pressure differences or springs trying to close the two faces together and so may create a non-contact seal that is more stable and reliable than hydrodynamic seals currently in use. A non-contact bearing is also disclosed having opposing surfaces with relative motion and one surface issuing higher than ambient pressure through a porous restriction, wherein the porous restriction is part of a monolithic porous body, or a porous layer, attached to lands containing a labyrinth, the porous restriction and lands configured to not distort more than 10% of a gap created from differential pressure between each side of the porous restriction.

A method for machining ribs or grooves on a workpiece such as a shaft or an air or gas axial bearing intended to be rotated about a longitudinal axis of a centrifugal compressor. All of the ribs or grooves are obtained at once by the machining tool on a workpiece portion driven such that it rotates, by moving the workpiece or the tool holder in a longitudinal machining direction, the machining tool moving back and forth with a machining position in contact with the workpiece and a position wherein it is not in contact with the workpiece from the start to the end of the workpiece portion. The back-and-forth movements of the machining tool are synchronised with the sinusoidal program set up in the machining unit, as well as with the desired, programmed arrangement of the ribs or grooves to be produced on the workpiece portion.

Systems and methods related to hydrodynamic bearings for use in X-ray sources are provided. In one aspect, a hydrodynamic bearing system includes a sleeve assembly including a cross-member fluidically dividing a first interior cavity from a second interior cavity, a first shaft positioned in the first interior cavity, and a second shaft positioned in the second interior cavity. The hydrodynamic bearing system may further include a first journal bearing including a first fluid interface surrounding at least a portion of the first cantilever shaft and configured to support radial loads and a second journal bearing including a second fluid interface surrounding at least a portion of the second cantilever shaft and configured to support radial loads.

A plain bearing (410) is fixed to a shaft hole (401) of an impeller (400) of the pump (100) so as to rotatably support the impeller (400) with respect to the shaft (300), and is restricted from moving in an axial direction by an annular restrictor (310) fixed to the shaft (300). On an end face (411) of the plain bearing (410) facing the restrictor (310), a lubrication groove (412) connecting a radially inner side and a radially outer side of the end face (411) to supply cooling water onto the end face (411) for lubrication, and a dynamic pressure generating groove (413) that introduces a flow of cooling water created by rotation of the impeller (400) to generate a dynamic pressure, are provided. The present bearing suppresses an increase in rotation torque of the impeller (400) during high speed rotation.

A fluid film bearing, includes a first and second part, wherein the first part includes at least two annular sliding surfaces, wherein the second part includes a respective group of pads for each of the annular sliding surfaces, wherein a respective pad sliding surface of each pad in a respective group supports the respective annular sliding surface, wherein the pads of each group are distributed in the circumferential direction along the second part, wherein at least one pad of a selected one of the groups is arranged such that spacing of the pads in the selected group along the circumference is irregular and/or wherein the selected or a selected one of the groups includes two different types of pads and/or wherein the pads of the or a selected one of the groups are offset in the circumferential direction with respect to the pads of a further one of the groups.

Solar trackers that may be advantageously employed on sloped and/or variable terrain to rotate solar panels to track motion of the sun across the sky include bearing assemblies and other mechanical features configured to address mechanical challenges posed by the sloped and/or variable terrain that might otherwise prevent or complicate use of solar trackers on such terrain.