Abstract: A fluid dynamic bearing including a sleeve and a counterplate captured within a shoulder on the sleeve and including a threaded mounting extension for mounting the assembly from a base or the like. A rotating shaft is incorporated within the sleeve; the shaft includes a thrust plate which rotates in a recess defined between the counterplate and the sleeve. To incorporate this assembly into a disc drive or the like, the threaded mounting extension only needs to be mounted within a base, with a nut screwed over the threaded mounting. The base typically includes a raised portion; the sleeve is cantilevered from this base for further stability and eliminate the possibility of vibration of the shaft and sleeve with rotation of the shaft. The end of the shaft distal from the threaded mounting supports a hub which in turn supports a backiron and magnet. The base supports a stator aligned with the magnet; energization of the stator will cause rotation of the hub and the shaft.

Abstract: A novel hydro-dynamic fluid bearing device is herein disclosed which comprises a cylindrical shaft, a substantially cylindrical bearing member for axially supporting the shaft rotatably in a cylindrical hole having a bottom surface, a supporting member fixed on one side of the shaft and the bearing member, and a rotation member fixed on the other side of the shaft and the bearing member and rotatably supported on the supporting member, grooves for generating hydro-dynamic fluid being formed on at least one of the outer peripheral surface of the shaft and the inner peripheral surface of the cylindrical hole of the bearing member, wherein the bearing member is made of a resin material, and the outer peripheral surface of the substantially cylindrical portion is fixed to an annular reinforcing member having a higher rigidity than the bearing member.

Abstract: In a hydrodynamic pressure bearing according to the present invention, the lubricating fluid held in the radial bearing portion is pumped toward the thrust bearing portion by grooves formed in the radial bearing portion. And the hydrodynamic pressure bearing is provided with a circumferential groove formed in the vicinity of the boundary region between the radial and thrust bearing portions so as to control the flow of lubricating fluid between the bearing portions depending on the amount of lubricating fluid held therein. The circumferential groove is formed on the sleeve member near the inner opening of a communicating hole which in turn axially passes through the thrust plate and communicates the gap defined by the shaft and the sleeve member therebetween with the external atmosphere. While a predetermined amount of lubricating fluid is retained in the gap, some extra lubricating fluid is also retained in the vicinity of the inner opening of the communicating hole.

Abstract: A spindle motor having a simplified construction with reduced axial and radial deflection while avoiding the half whirl phenomenon includes a motor frame, a rotating shaft supporting a rotor, a stator and stator coil, a permanent magnet opposing the stator, and a liquid dynamic pressure bearing. Magnetic centers of the permanent magnet and stator coil, in the axial direction of the rotating shaft, are substantially matched. The liquid dynamic pressure bearing comprises opposing surfaces of the rotating shaft and the housing. The rotating shaft has a disk-shaped thrust bearing portion disposed in a first portion of a cylindrical hole of the housing, and a radial bearing portion disposed in a second portion of the cylindrical hole. Lubricating oil fills a space between the cylindrical hole and the thrust bearing portion and radial bearing portion, and a presser ring is pressed and fixed into a third portion of the cylindrical hole to seal the bearing.

Abstract: A dynamic pressure bearing device comprises a rotary member mounted for rotation, and a dynamic pressure bearing rotatably supporting the rotary member. The dynamic pressure bearing has a stationary portion and a disk integrally connected to the stationary portion. The disk has surface portions defining thrust dynamic pressure bearing portions for supporting the rotary member in an axial direction and a radial dynamic pressure bearing portion for supporting the rotary member in a radial direction. A gap is disposed between the dynamic pressure bearing and the rotary member for receiving oil. A space is provided in fluid communication with the gap. The space has a central portion slanted downwardly in the radial direction for preventing leakage of the oil and has a diameter increasing gradually from the central portion in the radial direction.

Abstract: An electric spindle motor has a base assembly (19) and a hollow notatable hub (16) housing a motor. The hub (16) is mounted for rotation about an axis and a stator (12) is mounted on the base assembly (19) inside the hub (16). A liquid filled journal bearing (11, 21) acts between the base assembly (19) and the hub (16) to provide radial support of the hub (16). A gas filled thrust bearing (26, 27, 35) also acts between the hub (16) and base assembly (19) to provide at least axial support of the hub (16).

Abstract: A fluid bearing apparatus having a strengthened force for supporting a rotating member, which includes a herring bone-shaped dynamic pressure generating section and a spiral dynamic pressure generating section. A portion of the herring bone-shaped dynamic pressure generating section or the spiral dynamic pressure generating section is interrupted, or the spiral dynamic pressure generating section is connected to an end of the herring bone-shaped dynamic pressure generating section in order to prevent an operational fluid for generating a fluid pressure from counterflowing due to high speed rotation of the operational fluid.

Abstract: A fluid dynamic bearing cartridge including a sleeve and a counterplate captured within a shoulder on the sleeve and including a threaded mounting extension for mounting the assembly from a base or the like. A rotating shaft is incorporated within the sleeve; the shaft includes a thrust plate which rotates in a recess defined between the counterplate and the sleeve. To incorporate this assembly into a disc drive or the like, the threaded mounting extension only needs to be mounted within a base, with a nut screwed over the threaded mounting. The base typically includes a raised portion; the sleeve is cantilevered from this base for further stability and eliminate the possibility of vibration of the shaft and sleeve with rotation of the shaft. The end of the shaft distal from the threaded mounting supports a hub which in turn supports a backiron and magnet. The base supports a stator aligned with the magnet; energization of the stator will cause rotation of the hub and the shaft.

Abstract: The hydrodynamic bearing gap from one end to the other of the shaft and sleeve combination is effectively separated into sections, with the fluid in each bearing section being contained within that section. The viscosity of the fluid in each bearing section can then be selected to optimize the characteristics of the entire hydrodynamic bearing. Typically, the sections of the bearing adjacent each open end of the bearing would be filled with a fluid with relatively high viscosity. The remaining sections, toward the center of bearing, would typically be filled with a lower viscosity fluid, liquid or gas so that the power consumption within the motor itself would be minimized.

Abstract: A closed type thrust dynamic pressure bearing is capable of generating enough dynamic pressure for axially bearing a rotating member at the time of start-up without damage to an end face of a flange of the rotating member. The flange of the rotating member is housed in a housing in a closed state. V-shaped dynamic pressure generating grooves are provided at upper and lower end faces of the flange, while a plurality of holes axially passing through the flange are provided radially inside an annular region where the dynamic pressure generating grooves are provided. The total sum of cross-sectional areas of the holes is at least 1/30 of the area of the annular region. Oil sumps are provided at a receiving surface of the housing opposite to the lower end face of the flange.

Abstract: A recording disk apparatus comprises a clearance between a shaft and a thrust bearing portion tapered in a circumferential direction, a lubricant communication groove of a bearing covered by the shaft so that a lubricant on a radial bearing portion communicates with the lubricant on the thrust bearing portion through the lubricant communication groove, a lubricant circulating path which extends axially from the thrust bearing portion to the radial bearing portion to prevent the lubricant flowing out of the thrust bearing portion from returning directly to the thrust bearing portion without passing the radial bearing portion, and/or a clearance between a slide bearing and a magnetic fluid seal device substantially filled with a magnetic fluid lubricant.

Abstract: A bearing structure for a spindle motor is disclosed. The bearing structure provides a fluid bearing seal and support structure that may simultaneously addresses the problems of preventing oil leakage, of maintaining the bearing integrity under shock, of reducing oil evaporation and of minimizing distortion of the active bearing surface. The bearing structure includes a thrust plate coupled to a shaft and a bearing plate and load plate coupled to a sleeve, wherein the load plate urges the bearing plate towards the thrust plate, and wherein an adhesive is interposed between the load plate and the thrust plate. The adhesive may be an UV epoxy. The sleeve is operatively coupled to a stator, and the stator rotates the sleeve upon receiving a drive signal. The bearing further includes a diffusion barrier disposed between the sleeve and the stator. A second diffusion barrier is disposed between the load plate and the shaft.

Abstract: A fluid bearing in which a thrust bearing is mounted at both ends of a rotary shaft to minimize movement and oscillation of the rotary shaft regardless of a thrust load. The fluid bearing apparatus includes a pair of sleeves respectively mounted into one end of a pair of bearing brackets, a rotary shaft inserted into through holes of the respective sleeves, having a second kinetic pressure generating groove on a circumferential side opposite to the inside of the respective through holes, a pair of thrust bearings mounted into the other end of the bearing brackets, and a first kinetic pressure generating groove formed between any one of the thrust bearings and a section of the rotary shaft.

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 fluid bearing apparatus wherein a clearance between a surface of a thrust bearing supporting thrust load and a periphery of a rotary shaft can be adjusted by making a thrust bearing adjustable with respect to an end portion of the rotary shaft. This results in an enhanced efficiency and a stable rotation of the rotary shaft at a high velocity.

Abstract: In a rotating device which comprises a rotor; a radial bearing; a lower thrust bearing; a dynamic pressure generating means, a radial bearing area (mm.sup.2) which is the area of the rotor facing the radial bearing, a thrust bearing area (mm.sup.2) which is the area of the rotor facing the lower thrust bearing, and the rotor weight (g) are determined so as to satisfy the following formula:(a radial bearing area)/(thrust bearing area).times.(rotor weight)<300.

Abstract: It is an object of the invention to provide a hydrodynamic bearing which can be easily worked and assembled and in which a liquid is prevented from leaking.

Abstract: A fluid bearing apparatus equipped with a thrust bearing having a uniform pressure distribution for effectively supporting the thrust load by dividing uniformly the fluid pressure generated in a dynamic pressure generating groove of the thrust bearing. In the thrust bearing, by gathering the fluid in different directions, at least two bending points which generate the maximum fluid pressure are repeatedly formed.

Abstract: A vent is disclosed for a screw mounted support shaft of a fluid dynamic bearing for a spindle of a magnetic disk file. The support shaft for mounting a spindle bushing has an axial hollow center internally threaded at one end, and has upper and lower bearing journals for rotatably mounting the spindle bushing with a fluid lubricant. The bearing journals are separated by a recess having a vent passage between the recess and hollow center. A screw is threaded through the base plate or cover into the threaded end of the support shaft, mounting the support shaft to the base plate or cover. An air vent passage, such as a slit is provided axially either in the threaded end of the hollow center of the support shaft or in the screw, and radially across the end of the support shaft so the air bleed passage extends from the hollow center externally of the support shaft.

Abstract: A hydrodynamic bearing according to this invention and an electric motor with this hydrodynamic bearing include a shaft having a lubricating-fluid filling hole, one end of which is open toward the outside of the motor and the other end of which leads to the gap between the shaft and a sleeve in which lubricating fluid is filled. At least part of the filling hole except for the opening facing the outside of the motor has a smaller diameter than that of the outer opening. An elastic member formed of elastic material is inserted into the lubricating fluid fillng hole.

Abstract: The invention is a spindle motor including a rotor hub bearing a rotational load, lubricant-containing bearing systems rotatably supported by the rotor hub, and stator windings wound on a stationary member, so as to oppose the rotor magnet. At least a portion of the rotor hub is in a clean environment, with the motor substantially sealed by a sealing unit. The spindle motor has a leakage prevention unit which prevents the lubricant trying to leak out the bearing systems and out the motor, when centrifugal forces produced by a rotor hub rotating at a high speed are exerted on the lubricant.

Abstract: A bearing system for brushless DC motors is disclosed. The bearing system has an electromagnetic force generator in a bearing so as to generate an electromagnetic force or a magnetic force. The bearing system thus magnetically attracts the shaft when eccentricity of the shaft in the bearing is reduced during a high speed operation of the shaft, thus allowing the shaft to keep desired eccentricity in the bearing and increasing dynamic pressure of oil in the bearing and preventing a formation of an oil whirl, and improving dynamic characteristics of the motor such as low operational vibrations and noises during a high speed operation of the motor.

Abstract: A conical bearing apparatus having a dynamic pressure generating groove on the upper section of a conical bearing in order to increase a fluid pressure generated by the other dynamic pressure generating groove formed on the tapered surface of the conical bearing. As fluid generated by the two dynamic pressure generating grooves is completely used for raising the body of rotation, it is possible to raise the body of rotation in a short time. Accordingly, the friction between an optical polygon support and the upper section of the conical bearing is minimized and an abrasion of the optical polygon support or the conical bearing can be reduced. Furthermore, by reducing the overload of the conical bearing and optical polygon support, the stability in rotating the optical polygon is enhanced.

Abstract: A journal bearing apparatus capable of varying the clearance between a bush which protrudes from the inner surface of a sleeve in which a rotation shaft is inserted and the outer surface of the rotation shaft, in the longitudinal direction of a first dynamic pressure generating groove. Moreover, a journal bearing apparatus is capable of varying the clearance between one end of the rotation shaft and the surface of a thrust bearing, in the diametral direction of a second dynamic pressure generating groove. The clearance becomes wider towards the central part from the ends of the bush, or towards the central part from the edge parts of the surface of the thrust bearing. The shape of the end of the bush or the thrust bearing is preferably a circular arc. Thereby, the fluid pressure on the rotation shaft which faces the first and second dynamic pressure generating grooves is uniform.

Abstract: Disclosed is a motor including a stator, a rotor cooperating with the stator, a rotating shaft rotating with the rotor, the rotating shaft being provided in its bottom with a receiving space, and a semi-spherical bearing disposed in the receiving space of the rotating shaft. The semi-spherical bearing is truncated to define a planar portion and part of the receiving space is defined by a surface corresponding to the planar portion. The planar portion is provided with a plurality of grooves formed in a spiral-shape to allow for suction of air for smooth rotation.

Abstract: A hydrodynamic spindle motor of the present invention may include a shaft having a thrust bearing plate, an insert surrounding the shaft above the thrust bearing plate, and a sleeve surrounding the shaft below the thrust bearing plate. In one embodiment the thrust bearing plate is substantially centrally positioned along the longitudinal axis of the shaft. Preferably either the shaft has annular skewed herringbone shaft grooves or, alternatively, the insert has annular skewed herringbone insert grooves and the sleeve has annular skewed herringbone sleeve grooves. A set of circulation channels above the thrust bearing plate and a set of circulation channels below the thrust bearing plate preferably cross a shaft bore to allow for flow of lubricating fluid. A face seal may be formed between the lower radial cap surface of an end cap and an upper radial insert surface of the insert.

Abstract: An oil impregnated porous bearing unit includes an arrangement wherein an oil impregnated porous bearing containing ferro-fluid is fixed in a non-magnetizable housing, a ring shaped permanent magnet is disposed so that the ferro-fluid will exist in a gap between a rotary shaft, whereon the ring shaped permanent magnet is fixed, and the oil impregnated porous bearing, and the ferro-fluid circulates between a slide plane of the bearing and a body of the oil impregnated porous bearing with rotation of the rotary shaft by utilizing the magnetic attractive force of the permanent magnet and a capillary phenomenon in the oil impregnated porous bearing.

Abstract: A bearing structure for a hard disk drive includes a thrust bearing for forming a thrust air bearing for supporting a hub in an axial direction and a journal bearing for forming a journal air bearing for supporting the hub in a radial direction, being installed on the circumference of the shaft. According to the bearing structure, since each air bearing formed by the thrust and journal bearings noncontactly supports the hub in the axial and radial directions, the vibration occurring in a conventional ball bearing structure can be prevented. Therefore, a hard disk drive having high performance and low vibration characteristics can be manufactured.

Abstract: A compact electric motor construction employing fluid bearings for use in a disk drive apparatus includes a spindle having a shaft and a thrust plate and a hub assembly including a hub having an outer disk support portion with an inner thrust bearing surface located axially above the upper thrust bearing surface of the thrust plate. The hub also includes an inner sleeve which substantially surrounds the shaft and provides an air gap between its inner diameter and the outer diameter of the thrust plate. The air gap is vented to the interior of the motor cavity by vent passages. Transition grooves are provided on bearing surfaces adjacent all fluid seal zones for controlling the migration of bearing fluid in a radial direction and for providing a low fluid pressure region adjacent capillary seals at the ends of the shaft to contain the seal and prevent leakage.

Abstract: An air lubricated hydrodynamic bearing assemblage has a ceramic body and a ceramic shaft each made of tetragonal zirconium ceramic material. The bearing has flange portions on opposite ends a a generally cylindrical body. At least one of the flange portions has air channels formed therein in fluid communications with air inlet ports formed in the bearing body.

Abstract: A miniature motor having a rotor arranged within a casing within which a stator is mounted, and a rotary shaft of the rotor is supported by bearing units mounted on both ends of the casing. One of the bearing units is provided with a thrust receiving member for supporting an end portion of the rotary shaft in a thrust direction, and a bearing for supporting the rotary shaft in a radial direction within a rotary shaft insertion hole. The thrust receiving member having a dimension that is equal to or smaller than an inner diameter of a bottomed recess formed in the casing is laid on a flat bottom surface of the bottomed recess. The bearing is securely fixed within the bottomed recess and contacted against the thrust receiving member. The rotary shaft insertion hole is in fluid communication with a through-hole formed in a bottom plate of the bottomed recess.

Abstract: An apparatus for supporting a rotator, comprises a radial bearing and a thrust bearing, wherein at least one of a radial bearing surface, a supported surface of the rotor facing the radial bearing surface, a thrust bearing surface and a regulated surface of the rotor facing the thrust bearing surface is a rough surface having a center-line mean roughness not less than 0.3 and a surface facing the rough surface is a smooth surface having a center-line mean roughens less than 0.3.

Abstract: The hydrodynamic bearing arrangement comprises a journal sleeve defining a journal bore and a journal thrust surface. A shaft is mounted in the journal bore by means of a hydrodynamic journal bearing which permits rotation of the shaft and the journal sleeve relative to one another. A thrust plate extends transversely from the shaft and defines two hydrodynamic thrust bearings in combination with the journal thrust surface and a counterplate which is mounted adjacent to the thrust plate. A porous lubricant reservoir is mounted adjacent to the thrust plate. The porous lubricant reservoir serves to remove wear particles from the lubricant in the bearing arrangement, and provides a supply of lubricant to the hydrodynamic journal and thrust bearings should they become depleted of lubricant.

Abstract: A recording disk apparatus comprises a clearance between a shaft and a thrust bearing portion tapered in a circumferential direction, a lubricant communication groove of a bearing covered by the shaft so that a lubricant on a radial bearing portion communicates with the lubricant on the thrust bearing portion through the lubricant communication groove, a lubricant circulating path which extends axially from the thrust bearing portion to the radial bearing portion to prevent the lubricant flowing out of the thrust bearing portion from returning directly to the thrust bearing portion without passing the radial bearing portion, and/or a clearance between a slide bearing and a magnetic fluid seal device substantially filled with a magnetic fluid lubricant.

Abstract: A motor includes a shaft; a shaft retainer which retains the shaft and a thrust plate provided to the shaft, and thrust dynamic pressure fluid bearing means are provided between the thrust plate and the shaft retainer and radial dynamic pressure fluid bearing means are provided between the shaft retainer and the shaft. Between the outer circumferential surface of the thrust plate and the inner circumferential surface of the shaft retainer, a ring-shaped space is formed and oil is filled in a part of this ring-shaped space. Ring-shaped projections are provided on the outer circumferential surface of the thrust plate. When the motor is running at a high-speed, oil in the ring-shaped space is retained on the shaft retainer and through this oil, oil in the thrust dynamic pressure fluid bearings at the upper and lower surface sides are communicated with each other.

Abstract: A spindle motor includes a rotating hub for supporting one or more discs in a disc drive, and a hydrodynamic bearing system for supporting a hub for rotation, the bearing system includes a sleeve and a shaft fitted into an axial bore of the sleeve. The shaft and the sleeve rotate freely relative to one another, and together, define a journal bearing. The shaft supports an annular thrust plate. The thrust plate extends into a recess formed by an axial face stepped into the sleeve and a counterplate parallel to the axial face and the thrust plate and attached to the sleeve. A first surface of the thrust plate faces the axial face of the sleeve which has a groove pattern formed on it. A surface of the counterplate faces an opposed, second surface of the thrust plate which has a groove pattern formed on it, to form an effective fluid pumping system in the hydrodynamic bearing.

Abstract: A seal for a hydrodynamic bearing unit having a shaft and a sleeve includes a seal ring secured to the shaft and extending radially outwardly of the pair of spaced-apart hydrodynamic journal bearings defined between the seal ring and a thrust plate. The seal ring adjacently faces adjacent radial and axial portions of the sleeve. An annular taper capillary seal is defined between a diverging outer wall surface of the seal ring and the adjacent axial portion of the sleeve. A containment ring extends from the sleeve to surround a radial wall portion of the seal ring adjacent to an opening of the taper capillary seal and forms a secondary containment seal opening toward the shaft for preventing escape of the hydrodynamic bearing lubricant.

Abstract: A motor having a bracket with a stator coil for generating a magnetic field and a rotor hub with rotor magnets for receiving a rotation force from the magnetic field generated by the coil. Upper and lower dynamic pressure radial bearings are formed in between the sleeve and the rotary shaft. The lower end surface of the rotary shaft is formed with a spiral groove in which a lubricating fluid is filled to form a dynamic pressure thrust bearing. The spiral groove is formed by a circular hole at the center of the shaft, and a plurality of curved grooves each curving from the circular hole to the direction opposite to the rotation direction of the shaft and gradually increasing its width toward the outer circumference of the lower end surface of the shaft without reaching the circumference. The spiral groove functions to move the lubricating fluid outward in the radial direction from the center of the shaft, when the shaft rotates.

Abstract: A novel means for the design of a spindle having a shaft provided with a hydrostatic bearing end surface for resisting axial thrust force upon the end surface, the hydrostatic bearing being a self-compensating beating mounted circumferentially about the shaft near the end surface and having a fluid pressure supply groove providing fluid for the self-compensating bearing, the bearing being mounted upon an axially extending member one end of which serves as part of the end surface of the shaft and the other end of which serves as a reverse thrust surface, along with means for flowing fluid from the pressure supply groove radially across said reverse thrust end surface and through an opening extending axially between the reverse thrust end surface, and the end surface of the shaft, opposing the thrust force with pressure proportional to the axial position of the shaft and related to the degree of fluid compensation in the bearing.

Abstract: A thrust plate with grooved surfaces within a hydrodynamic bearing establishes pressure gradients which cause the lubricating fluid for the bearing to reliably remain within the region of the hydrodynamic bearing, with the pressure gradient imposed on the fluid causing the fluid to flow toward the center of the bearing rather than to be caused to be forced outward toward the far end of the bearing which could potentially result in a leakage of the fluid.

Abstract: A rotating-shaft hydrodynamic bearing assembly adapted for use in a rotating disk data store. The bearing assembly combines a plurality of spaced-apart radial journal bearings with a two-faced axial thrust plate to provide stiffness against runout at high rotational velocities. Fluid pressure is controlled on both sides of every fluid dement by bounding all radial fluid bearing layers and the dual thrust bearing layers with circumferential undercuts coupled to ambient pressure through a plurality of fluid-filled passages in the rotating shaft. Outward-biased surface-relief patterns are disposed in both axial thrust bearing layers to increase hydrostatic pressure and prevent cavitation in the non-bearing thrust-plate peripheral layer. The fluid bearing layers are disposed in a continuous pressure-controlled fluid film sealed at both ends by surface tension, thereby eliminating sources of air-bubble entrapment.

Abstract: A dynamic fluid bearing rotating apparatus comprises a shaft, a sleeve rotatably fitted to the shaft, a fixed member formed of a resin material, the fixed member being molded integrally with the sleeve, and a driver for rotating the shaft.

Abstract: An open-end spinning machine having a spinning rotor attached to a shaft is provided wherein the shaft of the spinning rotor is driven by a driving device. The shaft of the spinning rotor is held in the nips of pairs of rearward and forward supporting disks. During spinning operations, an axial force is generated in the axial direction of the free end of the rotor shaft. The open-end spinning device further comprises a radial support surrounding at least a portion of the circumference of the rotor shaft and disposed at least in part in the area between the free end of the shaft and the area of the shaft acted upon by the rearward pair of disks.

Abstract: A construction for a fluid bearing in a rotary spindle apparatus includes a spindle having first and second ends, and at least one thrust plate coupled to a shaft which is surrounded by a hub having an enclosing sleeve. The sleeve surrounding the thrust plate and shaft defines several gap regions where bearing fluid resides. A first radial gap region is defined between the shaft and sleeve and a second radial gap region is defined between the outer diameter of the thrust plate and the sleeve. A first axial gap region is defined by an upper surface of the thrust plate and the sleeve, and a second axial gap region exists between the lower surface of the thrust plate and the sleeve. A bearing fluid is disposed within these gap regions and forms capillary seals at first and second ends of the spindle. The thrust plate includes holes or pressure compensation ports which connect the first and second axial gap regions.

Abstract: A spindle system is comprised or a journal and thrust air bearing. The journal bearing; has two sets of opposing groove areas. The thrust air bearing has two sets of spiral grooves. The thrust air bearing is gimballed to compensate for misaligment. A bias contact member is connected to the rotating member along the axis of rotation and provides electrical grounding, The spindle system is especially applicable to mounting recording disks in a data storage disk drive.

Abstract: An electric motor construction includes a rotor housing and sleeve which surrounds a shaft/thrust plate. The thrust plate is enclosed in a dead end cavity and is surrounded by a fluid which forms a fluid bearing. The shaft has asymmetrical grooves which create a net pressure gradient from a capillary seal formed near the bottom of the shaft toward the dead end cavity. This helps maintain the capillary seal and reduce the risk of cavitation.

Abstract: A roller supporting structure has a shaft having first grooves for generating a dynamic pressure, and first and second retaining plates placed opposite both ends of a roller when the roller is mounted around the shaft. The first and second retaining plates have second grooves for generating a dynamic pressure on their roller-facing end faces. When the roller is placed in an axially central portion of the shaft, that is, in the middle between the retaining plates, there is left a predetermined gap between the roller-side end face of each retaining plate and each end face of the roller. The gap is large enough so that the second grooves of the first and second retaining plates do not generate dynamic pressure between these retaining plates and the roller. The second grooves of one of the first and second retaining plates generate dynamic pressure when the roller is displaced from the axially central portion toward the one retaining plate.

Abstract: A bearing device suitable for a spindle motor, which comprises a base, a spindle stood on a central portion of the base, a radial cylindrical member (4) fixed on the spindle, a pair of thrust plates (3) secured to both end surfaces of the radial cylindrical member, and a radial sleeve (6) rotatably supported by the thrust plates (3) and the radial sleeve (6), wherein a radial hydrodynamic bearing is formed by the radial cylindrical member (4) and the radial sleeve (6), thrust hydrodynamic bearings are formed by both end portions of the radial sleeve (6) and the thrust plates (3), a gas is employed as a fluid for generating dynamic pressure in the thrust hydrodynamic bearings, the radial bearing has a minute clearance, a chamfer portion is provided on the outer periphery of each end of the radial cylindrical member (4), and another chamfer portion is provided on the inner periphery of each end of the radial sleeve (6), thereby providing an air gap (13) at each axial end of the radial hydrodynamic bearing, whic

Abstract: A spindle motor with an H-type pneumatic dynamic bearing has a high durability against repeated starts and stops of rotation. The H-type bearing is composed of a radial bearing member, thrust plates firmly fixed to opposite ends of the radial bearing member and a cylindrical radial sleeve, which form a radial pneumatic dynamic bearing and thrust pneumatic dynamic bearings. A stator core is fixedly secured around a rotary member, which is in turn fixedly secured around the cylindrical radial sleeve. A total thrust clearance a+a' of the thrust bearings is represented by an inequality of (a+a')/A< 2.5/10.sup.4 based on a sliding surface diameter A of each thrust plate, a and total radial clearance b+b' of the radial bearing is represented by an inequality of (b+b')/B<5/10.sup.4 based on a sliding surface diameter B of the radial bearing member.

Abstract: A motor having a dynamic-pressure type bearing device includes a cylindrical sleeve fixedly secured to a base, a shaft rotatably inserted into a hollow of the cylindrical sleeve, a hub fixedly secured to an end portion of the shaft, a ring-like rotor magnet fixedly secured to the hub, and an armature fixedly secured onto the base to be in opposed relation to the rotor magnet so as to constitute a motor driving device. Further, the motor has a disc-like plate coaxially and fixedly secured to an end portion of the shaft to have a diameter of the disc-like plate greater than a diameter of the shaft and a plate disposed in opposed relation to a surface of the disc-like plate.