A bearing system including a foil bearing assembly positioned within the cylindrical bore of the sleeve. The foil bearing includes a top foil layer and an outer layer. The bearing system includes a driveshaft including a recess axially aligned with the top foil layer. The recess defines a cavity having a volume and includes a leading end at a first circumferential position and a trailing end at a second circumferential position. The volume of the cavity decreases from the leading end to the trailing end.

A semi-floating bearing (multilobe bearing) including: an annular main body through which a shaft is inserted; and a radial bearing surface formed on an inner peripheral surface of the main body, the radial bearing surface including a plurality of arc surfaces having different curvature centers and disposed adjacent to each other in a circumferential direction of the main body, and a minimum distance Ra between a central axis of the shaft and the arc surface, a curvature radius Rb of the arc surface, and a radius Rs of the shaft satisfying relationships expressed by the following Formulas (1) and (2). Ra/Rs?1.001 . . . (1), (Rb?Ra)/0.9?(Rb?Rs)?(Rb?Ra)/0.6 . . . (2) provided that Ra is the minimum distance between the central axis of the shaft and the arc surface, Rb is the curvature radius of the arc surface, and Rs is the radius of the shaft.

A floating-bush bearing device (1) for rotatably supporting a rotational shaft (2), includes: a floating bush (3) having a cylindrical shape and including a bearing hole (33) into which the rotational shaft (2) is to be inserted; and a bearing housing (4) which rotatably houses the floating bush (3). At least one of an inner peripheral surface (31) of the floating bush (3), an outer peripheral surface (32) of the floating bush (3), or an inner peripheral surface (41) of the bearing housing (4) includes, in a cross section in an axial direction thereof, a plurality of land portions (311, 321, 411) having a true arc shape which is a part of a true circular shape, and a plurality of recess portions (312, 322, 412) being disposed at a position recessed from the land portions, the recess portions being configured such that a distance between the recess portions and a virtual true circular line (31a, 32a, 41a) passing through the land portions increases in a direction opposite from a rotational direction of the rotational shaft (2) from end portions (311b, 321b, 411b) of the land portions opposite from the rotational direction of the rotational shaft.

A groove-type dynamic pressure gas radial bearing, comprises a bearing outer sleeve and a bearing inner sleeve, the outer circumferential face and the two end faces of the bearing inner sleeve are respectively provided with regular groove-type patterns, and the groove-type pattern in one end face is in mirror symmetry with the groove-type pattern in the other end face, and the axial contour lines of the groove-type patterns in the outer circumferential face and the radial contour lines of the groove-type patterns in the left and right end faces are in one-to-one correspondence and are connected with each other. The groove-type dynamic pressure gas radial bearing provided by the invention can achieve a load capacity of 1-3 kg and a limit rotating speed of 200,000 rpm to 450,000 rpm, it can realize the application of groove-type dynamic pressure gas radial bearings in ultra high-speed areas.

A bearing arrangement includes a shaft, at least one contact bearing and at least one non-contact bearing and a controller. The controller is configured to control a magnitude of a restoring force applied to the shaft by the non-contact bearing in accordance with a sensed parameter such that a stiffness of the shaft is modified such that one or more resonance frequencies of the shaft are moved away from one or more external forcing frequencies.

An electric machine coupled to rotating machinery includes a rotor and a stator, and the method of control of an electric machine and an electric machine control system. The method includes sensing one or more parameters indicative of one or more resonance conditions of the rotating machinery, and comparing the sensed parameter to a predetermined threshold to determine whether the rotating machinery is operating at the resonance condition. Where the rotating machinery is determined to be operating at the resonance condition, adjusting a magnetic field of one or both of the rotor and the stator to provide a predetermined torque to the rotating machine, to modulate the stiffness of the rotational machinery, and thereby move the resonance condition away from the current rotating machinery conditions.

A bearing system including a foil bearing assembly positioned within the cylindrical bore of the sleeve. The foil bearing includes a top foil layer and an outer layer. The bearing system includes a driveshaft including a recess axially aligned with the top foil layer. The recess defines a cavity having a volume and includes a leading end at a first circumferential position and a trailing end at a second circumferential position. The volume of the cavity decreases from the leading end to the trailing end.

A hydrodynamic plain bearing has a bearing shell with an inner surface forming a bearing surface for a rotating shaft or the like. The bearing surface, in order to form a bearing having a multi-wedge bore, has a plurality of surface segments arranged one after the other in the circumferential direction and each forming a circle segment having a radius R by way of the inner circumference of the surface segments. The center point of the circle segment of each surface segment is shifted relative to a center point of the bearing shell by an eccentricity. The bearing shell has two halves, each extending over 180 of the bearing surface and joined in a joint plane. At least one surface segment is offset from the center point of the bearing shell along an offset plane at an angle to the joint plane in the circumferential direction of the bearing shell.

A turbocharger including a housing and a rotary assembly disposed within the housing and including a turbine wheel and a compressor wheel attached to one another by a shaft. The rotary assembly being subject to aero-load in a lateral direction. A bearing is disposed in the housing and rotatably supports the shaft, the bearing including an inner bearing surface that engages the shaft and an outer bearing surface that engages the housing, the outer bearing surface having a pair of axially extending recessed grooves extending at least partially along the bearing. The pair of axially extending grooves being located perpendicular to the aero-load direction.

A turbocharger including a housing and a rotary assembly disposed within the housing and including a turbine wheel and a compressor wheel attached to one another by a shaft. The rotary assembly being subject to aero-load in a lateral direction. A bearing is disposed in the housing and rotatably supports the shaft, the bearing including an inner bearing surface that engages the shaft and an outer bearing surface that engages the housing, the outer bearing surface having a pair of axially extending recessed grooves extending at least partially along the bearing. The pair of axially extending grooves being located perpendicular to the aero-load direction