A rolling deep groove ball bearing includes a bearing outer ring (1), a bearing inner ring (2), a plurality of large rolling balls (3) and special-shaped rollers (4), where the large rolling balls (3) and special-shaped rollers (4) are arranged between the bearing inner ring (1) and the bearing outer ring (2), and the large rolling balls (3) and the special-shaped rollers (4) are arranged at intervals. For the rolling deep groove ball bearing, the rolling balls (3) and the bearing raceway realize the pure rolling, where high linear velocity is subjected; the bearing capacity is large; the noise is low; the reliability is high and the service life is long. The deep groove ball bearing has no gap for installing balls and is simply assembled.

Two hybrid ball bearings and a compressor bearing arrangement with two hybrid ball bearings for a rotatable support of a rotor of the compressor versus a stator of the compressor. The two hybrid ball bearings are arranged face-to-face or back-to-back, are designed with an optimal axial clearance depending on the inner diameter of a ring-shaped inner raceway element one of the hybrid ball bearings respectively a pitch diameter of one of the two hybrid ball bearings for a long bearing life in connection with an optimal compressor operating performance.

A rolling bearing including a cage is provided. The cage includes, on its outer peripheral surface, a plurality of ridges protruding radially outwardly, and circumferentially spaced apart from each other. The ridges extend in the axial direction or in an oblique direction or directions relative to the circumferential direction. The ridges are capable of coming into contact with the inner peripheral surface of the outer ring through lubricating oil.

It is an object of the present invention to provide a sliding member, a rolling bearing, and a cage each having a sliding surface excellent in a sliding property thereof even in the presence of lubricating oil and under conditions of a high sliding speed and a high contact pressure. The sliding member is used under an oil lubrication environment and has a sliding layer formed on an iron-based metal material. The sliding layer consists of a foundation layer including heat-resistant resin and a first fluororesin layer both formed on a surface of the iron-based metal material. A second fluororesin layer is formed on a surface of the foundation layer. After the foundation layer and the second fluororesin layer are calcined, the second fluororesin layer is irradiated with radiation rays. The heat-resistant resin does not thermally decompose when the foundation layer and the second fluororesin layer are calcined.

A rolling deep groove ball bearing includes a bearing outer ring (1), a bearing inner ring (2), a plurality of large rolling balls (3) and special-shaped rollers (4), where the large rolling balls (3) and special-shaped rollers (4) are arranged between the bearing inner ring (1) and the bearing outer ring (2), and the large rolling balls (3) and the special-shaped rollers (4) are arranged at intervals. For the rolling deep groove ball bearing, the rolling balls (3) and the bearing raceway realize the pure rolling, where high linear velocity is subjected; the bearing capacity is large; the noise is low; the reliability is high and the service life is long. The deep groove ball bearing has no gap for installing balls and is simply assembled.

A rolling bearing arrangement having a first and a second raceway element, and rolling bodies being arranged between the two raceway elements so that the two raceway elements are rotatable against each other in the manner of a rolling bearing, a space between the raceway elements in which the rolling bodies are rolling off comprising a lubricating grease, at least one sensor element for sensing temperature, at a specific point of the rolling bearing, particularly in the space, and for sensing speed of the rolling bearing and a unit receiving the sensed temperature and speed, calculating from the profiles of the sensed temperature over time and from the speed over time via a calculated energy imposed on the grease a used and/or remaining period of the grease life-time.

Two hybrid ball bearings and a compressor bearing arrangement with two hybrid ball bearings for a rotatable support of a rotor of the compressor versus a stator of the compressor. The two hybrid ball bearings are arranged face-to-face or back-to-back, are designed with an optimal axial clearance depending on the inner diameter of a ring-shaped inner raceway element one of the hybrid ball bearings respectively a pitch diameter of one of the two hybrid ball bearings for a long bearing life in connection with an optimal compressor operating performance.

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 tribologically modified polyoxymethylene polymer composition is disclosed. The polyoxymethylene polymer composition is comprised of a polyoxymethylene polymer and at least one tribological modifier. The tribological modifier may comprise an ultra-high molecular weight silicone having a kinematic viscosity of greater than 100,000 mm.sup.2 s.sup.?1. When tested against itself, the composition of the present disclosure exhibits an extremely low dynamic coefficient of friction and produces no discernible noise over a very broad temperature range, such as from ?20? C. to 60? C.

Provided is a rotation transmission shaft unit that is easy to install and that can effectively transmit rotation at high rotational speed and high torque. Also provided are a transmission device and a test device that use the shaft unit and transmit high torque and high rotation over a long span.

A rotation transmission shaft unit that is easy to install and axially align and that can rotate at high torque and high speed is realized by providing bearings to both ends of a rigid cylinder and rotatably support, by using the bearings, a central shaft made of a fiber-reinforced resin. Stability of the axial position of the central shaft can be achieved simply by supporting the rigid cylinder of the shaft unit, and since the rotation transmission shaft unit is a unit, it is easy to attach in and detached from an installation position and is easily centered with respect to the axis of a rotating machine, and because rotation can be transmitted over a long span, the speed of a motor test bench and an EMC test device can be increased.