Abstract: A hydrodynamic thrust bearing assembly for supporting a reduced diameter end portion of a rotating shaft includes a thrust button or plate having one end thereof abutting an end of the reduced diameter end portion to absorb axial forces exerted by the rotating shaft, and a hollow cylindrical bearing sleeve disposed around the reduced diameter end portion, and wherein the thrust button has a central aperture for introduction of a process fluid and a plurality of slots in the one end of the thrust button and communicating with the central aperture in the thrust button and with a helical groove formed in an interior surface of the sleeve.

Abstract: A rotary polygon mirror optical scanning device comprises a fixed shaft and a rotor having a shaft hole, to which the fixed shaft is inserted, and is rotatably supported against an outer perimeter of the fixed shaft. The device also includes a hydrodynamic bearing mechanism for supporting the rotor. The hydrodynamic bearing mechanism has first and second hydrodynamic pressure generating grooves which are, axially away from one another, formed on at least one of an outer surface of the fixed shaft and an inner surface of the shaft hole of the rotor. A rotary mirror is mounted on the rotor. A motor portion is arranged for rotating the rotor. The fixed shaft has a diameter bearing which is one-third or more of a diameter of a polygonal inscribed circle of the rotary polygon mirror. An area for cutting the first hydrodynamic pressure generating groove is arranged at an axially identical position with the rotary polygon mirror.

Abstract: In a spindle motor for a driving a memory disk, a is closed space formed by a sleeve metal, an end portion of a shaft and a thrust plate. The closed space is connected to outside open space by a connection path, thereby effectively discharging undesirable air in an assembling stage.

Abstract: A dynamic-pressure gas bearing wherein a rotational shaft is disposed to surround an outer circumference of a stationary shaft or to be surrounded by an inner circumference of a stationary shaft, and a dynamic pressure is generated between the stationary shaft and the rotational shaft through rotation of the rotational shaft, characterized in that a water relief portion is provided. In a dynamic-pressure gas-bearing having a water relief portion, even when the bearing is used in a high-humidity environment or even when water (water vapor) contained in a gas liquefies due to high pressure, a pressure change, or the like, the water relief portion prevents a water film from being formed to thereby prevent an increase in a shear force acting between the stationary shaft and the rotational shaft.

Abstract: A hydrodynamic bearing device includes a gap between a shaft and shaft holder. One of the shaft and shaft holder has a recess for separating by capillary action lubricant at an upper portion of the gap above the recess from lubricant at a lower portion of the gap below the recess. The separated lubricant at the recess forms a gas interposition in order to reduce lubricant resistance. A hole formed in the shaft or shaft holder communicates the air interposition to the external atmosphere to prevent air expansion and the build-up of bubbles in the lubricant which could otherwise cause contamination and leakage. An axially extending storage groove supplies by capillary action lubricant from either the upper or lower portion to the other portion if lubricant in the other portion decreases due to vaporization or leakage, whereby the loss of lubricant is minimized and the operating life of the surrounding components are increased.

Abstract: A helically continuous projection 1a is formed around a sliding surface 1A of a sliding bearing 1 at a given pitch p. The surface roughness h of the sliding surface 1A, including the projection 1a, is chosen to be equal to or less than one-half the height H of the projection. This provides a sliding bearing 1 which exhibits an improved running-in performance.

Abstract: An integrated spindle shaft and the like and self-compensating hydrostatic bearing assembly, obviating the need for external bearing sleeve constructions, in which a cylindrical bearing bore is so provided having circumferential grooves connected to pressure supply and drain systems, and in which collection space pressure supply and fluid drain grooves are provided that cooperate with circumferential collector grooves and pockets, such that when fluid flows axially from the pressure groove areas across the shaft into the collector grooves, in proportion to the radial clearance between the shaft surface and the bore, in conjunction to the pocket opposite to the collector groove, to provide a restoring force in proportion to the radial displacement of the shaft.

Abstract: A self-lubricating hydrodynamic spindle bearing comprising a stationary shaft including a conical, inwardly tapered surfaces extending axially form outer regions of the shaft toward a center connecting region of the shaft, a rotatably mounted sleeve surrounding the shaft and including surface regions flared axially inwardly toward a center region of the sleeve, the tapered surface regions and the flared surface regions defining a bearing gap for the hydrodynamic bearing, the sleeve defining a connection region adjacent the connecting region between the tapered surfaces of the shaft, the connection region including a tube collapsible in response to a change in internal pressure in the connection region to stabilize stiffness and power consumption in the bearing.

Abstract: A disk for use in a bearing assembly of an open end spinning machine having four disks arranged in two pairs and which operate at up to 15,000 RPM's while the rotor shaft turns at up to 125,000 RPM's. The disk pairs are arranged to form a wedge shaped gap supporting the shaft of a spinning rotor for rotation. Each disk comprises a metallic hub which mounts a synthetic ring. The synthetic ring has a spinning rotor contact surface comprising a shoulder arranged atop a helically disposed rib which extends around and across the contact surface. The shoulder imparts an axial thrust against the spinning rotor during operation of the spinning machine.

Abstract: An integrated bearing and pump assembly is formed by positioning a hydrodynamic pump coaxially with respect to a hydrodynamic bearing. The integrated assembly provides pressurized fluid for use within the device incorporating the bearing. The hydrodynamic pump comprises a secondary hydrodynamic bearing incorporated into the primary bearing assembly. The secondary bearing is optimized for high flow pumping applications rather than the high pressure, zero flow requirements of the primary bearing. When the bearing assembly is rotated, fluid flow is provided.

Abstract: A plastic part is molded of a plastic with an inner body of crystalline plastic and an outer surface layer of an amorphous plastic. The amorphous surface layer withstands friction loading at least during an initial break-in period. In one embodiment, the amorphous surface is formed by using a higher plastic melt temperature and/or a lower mold temperature than normal. In another embodiment, an intermediate part is molded as a crystalline intermediate part, and a surface layer is heated and quenched to form the amorphous surface layer on the final part. A bearing cage is molded by injecting the plastic melt at a single point intermediate the ends of a single bar of the bearing cage to permit formation of the desired amorphous layer on rails connected to the ends of the bars.

Abstract: A spindle assembly having a spindle used as a rotary shaft or a machine tool or the like, at least one bearing sleeve for supporting the spindle as an externally pressurized gas bearing without touching it, a plurality of journal bearing clearances formed between the spindle and the bearing sleeve, and a housing accommodating the bearing sleeve. The bearing sleeve is formed with an annular groove for guiding compressed gas in a circumferential direction, at least three axially-extending gas supply grooves for directing the compressed gas through gas supply restrictor holes into the journal bearing clearances, and at least one axially-extending exhaust groove for discharging the compressed gas from said journal bearing clearances. The axial gas supply grooves and the exhaust groove have a plurality of gas supply restrictor holes and discharge holes, respectively.

Abstract: A feed mechanism is constructed with a piezoelectric actuator embedded in the front end of a square sliding shaft, which is supported by hydrostatic guide surfaces formed on a guide base for sliding motion in the axial direction. A cooling jacket having a helical channel on its outside surface is provided at the periphery of the piezoelectric actuator. A part of pressurized fluid fed to the hydrostatic guide surfaces is led to the helical channel of the cooling jacket through a cooling oil feeding channel formed in the sliding shaft, and fluid in the helical channel is drained to a low pressure space through an oil discharging channel formed in the sliding shaft.

Abstract: A refrigeration system (300) having a compressor (12) with a rotor (20) rotatably supported by a plurality of hydrodynamic bearings (22, 24) lubricated by oiless pressurized liquid refrigerant and pressurizing refrigerant which flows to a condenser (34) providing liquid refrigerant which flows to an evaporator (68) in fluid communication with the condenser and the compressor in accordance with the invention includes a first refrigerant circuit (302), coupled to the compressor, for providing pressurized liquid refrigerant to the hydrodynamic bearings from the compressor without flow through a subcooler; and a second refrigerant circuit (304), coupled to the hydrodynamic bearings and to the evaporator including at least one subcooler (42 and 44), for providing a flow of refrigerant from the hydrodynamic bearings through the at least one subcooler to the evaporator, the at least one subcooler cooling the refrigerant flowing between the hydrodynamic bearings and the evaporator.

Abstract: An oil film bearing for rotatably supporting the journal surface of a rolling mill roll neck on a hydrodynamically maintained oil film. The bearing includes a bushing having outlets adapted to axially interrupt the load carrying continuity of the oil film by draining oil from the load zone at locations intermediate to the ends of the bushing, thereby subdividing the load zone into at least two axially separated pressure zones. Position sensors are located between the pressure zones to monitor the spatial relationship or oil film thickness between the bushing and the journal surface. The journal surface is defined by at least two sleeve segments received on and fixed relative to the roll neck. Adjacent ends of the sleeve segments are aligned radially or in a coplanar relationship with the axial separation between the pressure zones. Temperature sensors monitor the temperature of the oil being drained through the aforesaid outlets.

Abstract: An axially symmetric journal air bearing having areas on the internal surface of the stator, isolates pressurewise from other areas, having selected dimensions and means to apply selected pressures to said areas, wherein said selected dimensions and pressures are selected to maintain equilibrium of the rotor when it is subject to a large radial load.

Abstract: A bearing system comprises two hydrodynamic bearings by means of which two bodies having two cooperating bearing surfaces are supported for rotation relative to one another about an axis of rotation. At least one of the bearing surfaces of each of the bearings has patterns of helical grooves for building up pressure in a lubricant between the bearing surfaces during rotation. Further, the bearing system comprises a chamber which is arranged between the hydrodynamic bearings and which serves as a reservoir for an additional amount of lubricant. The chamber is bounded by two cylindrical wall portions. The two cylindrical wall portions off-set from each other to build up pressure in the lubricant in the chamber during rotation.

Abstract: An oil film bearing for rotatably supporting the journal surface of a rolling mill roll neck on a hydrodynamically maintained oil film. The bearing includes a bushing adapted to interrupt the load carrying continuity of the oil film and to subdivide the load zone into compound pressure zones.

Abstract: In a superprecision lathe of the present invention, a main spindle having mounted at one end thereof a vacuum chuck rotatably supported in an air bearing fixed on a headstock. There is formed within the main spindle a first vacuum passage connected to the vacuum chuck and opened at the outer surface of the main spindle, and a second vacuum passage formed in the headstock and of which an open end to be connected to a vacuum pump and is opened at the inner surface of the air bearing. The first vacuum passage is connected to the second vacuum passage through an interconnection region defined by two annular grooves formed at the opposite positions of the outer surface of the main spindle and the inner surface of the air bearing; therefore, it is not necessary to use a specific sealing member, any external vibration is not transmitted to the main spindle, and the object can be worked effectively with a high speed rotation of the main spindle.

Abstract: An aerostatic or aerodynamic bearing comprising a stationary part and a movable part with cooperating bearing surfaces between which there is formed a bearing gap which at one area communicates with an air inlet and at another area opens into the atmosphere. The air inlet comprises one or more filters, and at least one of the bearing surfaces is provided with a pressure-equalizing groove near the area at which the bearing gap opens into the atmosphere.

Abstract: A static pressure gas bearing apparatus equipped with a static pressure gas bearing that can support in floated state the rotating shaft of the turbocharger to be placed on an internal combustion engine comprises an air pump device for pressurizing and supplying a gas, an accumulator for storing the pressurized gas supplied form the air pump device, a pressurized gas supply passage device for connecting the accumulator to the static pressure gas bearing, a bypass passage device for connecting the air pump device to the static pressure gas bearing by bypassing the accumulator, and a control device for controlling the opening and the closing of the bypass passage device in response to the internal pressure of the accumulator.

Abstract: A radial bearing comprising a cylindrical bearing member and a shaft arranged therein, the member and the shaft being rotatable with respect to each other and one of the cooperating bearing surfaces of the member and the shaft being provided with a pattern of shallow lubricant-pumping grooves which, during relative rotation between the member and the shaft, build up a pressure in a lubricant present between the shaft and the member. In one axial zone of the member or the shaft the relevant bearing surface is provided along one half of its circumference with a groove pattern which is arranged to pump in one circumferential direction, and along the other half of its circumference with an identical groove pattern which is arranged to pump in the opposite circumferential direction.

Abstract: The friction conditions in a hydrodynamic surface bearing having a bearing metal layer in which no softer bearing metal is embedded are substantially improved in that the bearing surface is formed with grooves, which are distributed over the width of the bearing and include with the direction of movement in the bearing an angle not in excess of 20.degree.. These grooves cooperate with the moving element to be received in the bearing so as to define passages which ensure that a minimum hydrodynamic pressure will be built up in the lubricant.