Abstract: Multifunctional components enable the construction of economical motor assemblies. A first embodiment of the present invention provides a hub, cup, spindle, and base assembly for a motor assembly having at least one journal bearing, at least one thrust bearing, and at least one fluid seal. A second embodiment of the present invention provides a hub, spindle, and base with integrated cup assembly for a disc drive bearing having at least one journal bearing, at least one thrust bearing, and at least one fluid seal. In a third embodiment, a hub is rotatably assembled with a spindle coupled to a thrust bearing, prior to assembly with a base. In further embodiments, motor assemblies comprise the above embodiments combined with stator and rotor assemblies.

Abstract: A fluid dynamic bearing is constructed to support stably a rotating body to which a non-uniform force is applied, and a hard disk drive (HDD) employing the fluid dynamic bearing is provided. The fluid dynamic bearing includes a journal bearing part supporting a rotary shaft in a radial direction of the rotary shaft, a thrust part formed at one end of the rotary shaft, a thrust bearing part facing the thrust part and supporting the rotary shaft in a longitudinal direction of the rotary shaft, and a plurality of grooves formed on a surface of the thrust bearing part and/or the thrust part. The plurality of grooves include a first groove group including a plurality of grooves having the same shape and arrangement, and a second groove group adjacent to the first groove group and including at least one groove asymmetric with respect to the grooves of the first groove group.

Abstract: An object of the present invention is to provide a hydrodynamic bearing type rotary device which can improve rotation performance, suppress a friction torque, and reduce power consumption of motor, and a recording and reproducing apparatus including the same. A shaft having a flange on one end and a hub on the other end is provided with a bearing of a sleeve so as to be rotatable. The sleeve includes a communication hole. A third gap between the hub and the sleeve end surface is a flow path, and is connected to the communication hole. Provided that a first gap between a thrust plate 4 and the flange 3 is S1, a second gap between the flange 3 and a lower end surface of the sleeve 1 is S2, and a third gap between the upper end surface of the sleeve 1 and the hub 7 is S3, widths of the gaps satisfy the relational expression, S3>(S1+S2).

Abstract: A fluid dynamic bearing. A shaft is fit in the sleeve and rotates with respect thereto. A lubricant is filled between the shaft and the sleeve. At least one elliptical groove is formed on either the shaft or the sleeve and between the shaft and the sleeve. When the shaft rotates with respect to the sleeve, the lubricant is filled in the elliptical groove.

Abstract: A fluid dynamic pressure bearing device includes a shaft member (5) and a bearing member (41), at least one of the shaft member or the bearing member being rotatable with respect to the other. A shaft member-side annular member (13) is fixed with respect to the shaft member. The shaft member-side annular member includes a large-diameter rim portion and a small-diameter outer circumferential surface portion. A bearing member-side annular member (14) is fixed with respect to the bearing member. The bearing member-side annular member includes an inner circumferential large-diameter step portion, and a small-diameter inner circumferential surface portion.

Abstract: Disclosed is a device having a rotor that is adapted to be rotated relative to a stator, with hydrostatic bearings being used as radial bearings and as axial bearings of the rotor. A motor is provided as a direct drive, having a ring-shaped part and also a plurality of motor segments which are in magnetic engagement with the ring-shaped part. In order to generate additional bearing load force, additional motor segments having permanent magnets are provided. For reasons of safety, axial support rolls are provided which, when the motor has attained a given bearing load force, are spaced from a running face of the rotor, and which, in a case of too low or an absence of load force, prevent a displacement of the rotor away from the axial bearings.

Abstract: A fluid dynamic bearing mechanism for a motor (1) suitable for use in a hard disk drive and having a compact and thin shape, high bearing rigidity, and high rotating accuracy, and which securely keeps the rotor member (6) in place against shocks, and allows the inspection of lubricant supply amount easily. A fluid dynamic bearing mechanism having a capillary seal part (12) on one end of lubricant supply part formed by a minute gap including dynamic pressure grooves (10) formed on a shaft member (5) or a bearing member (4) is provided. An annular member (13) is fitted on the shaft member at the location corresponding to the capillary seal part, another annular member (14) is fitted on the bearing member at the location corresponding to the capillary seal part, a taper or step (13a, 14a) is formed on the outer peripheral surface of the annular member on the shaft member side and the inner peripheral surface of the annular member on the bearing member side.

Abstract: A hydrodynamic bearing device 4 comprises a shaft 41, a second thrust flange 41c, a sleeve 42, a radial bearing 71, and a thrust bearing 73. The second thrust flange 41c is fixed near one end of the shaft 41. A third cylindrical protrusion 42e that protrudes farther in the axial direction than the second thrust flange is fixed to or integrally machined at one end of the sleeve 42. A notch 50 that communicates between a radial inner space and a radial outer space separated by the third cylindrical protrusion 42e is provided to the third cylindrical protrusion 42e.

Abstract: A bearing assembly for use in an electric motor minimizes the generation of a negative pressure. In the bearing assembly, gaps are formed between a shaft provided with a flange portion, a ring member mounted on the shaft, and a sleeve member with a through hole formed therein are continuously filled with lubrication oil. When a rotor rotates, the rotor is supported by a fluid dynamic pressure. In the bearing assembly, herringbone grooves are formed in an upper surface of the flange portion of the shaft fixed to a base plate. When the sleeve member rotates with respect to the shaft, ends of all of the herringbone grooves and the through hole are superposed on each other sequentially. Thus, the lubrication oil can be efficiently supplied to an outer peripheral region in the thrust dynamic pressure bearing mechanism in which the negative pressure is most prone to be generated, and generation of the negative pressure can be efficiently minimized.

Abstract: A fluid dynamic bearing is provided. A structure in which a shaft member and an annular member fitted about the shaft member are rotatably supported by a bearing member and an annular member on the bearing member has a fifth gap for storing a lubricating fluid and supplying it to a second gap below the annular member on the shaft member and a third gap around its outer periphery through a fourth gap. The fourth and fifth gaps are tapered to produce a capillary drawing force toward the third and second gaps, so that the lubricating fluid may be supplied effectively from the fifth gap to the second and third gaps. This makes it possible to suppress any sudden formation of a reduced pressure upon exposure to impact or vibration to prevent the leakage of any lubricating fluid caused by the generation of bubbles, while making up for the loss of any lubricating fluid by vaporization.

Abstract: A hydrodynamic bearing device which realizes power saving, reduction of a time period necessary for stabilizing rotation, and enhancement in durability to startup and halting of the motor at the same time by accelerating circulation of a lubricant in the vicinity of a flange with torque loss being kept low is provided. A flange (3) is fixed to one end of a shaft (2). On an inner surface of one of openings of a sleeve (1), a step portion (1C) is provided. When the shaft (2) is inserted into the sleeve (1), the flange (3) is in close vicinity to the step portion (1C). An inner diameter of the step portion (1C) is smaller in end portions in an axial direction than in a central portion. Thus, a gap between an outer surface (3C) of the flange (3) and a surface of the step portion (1C) which opposes the outer surface (3C) is narrow in the vicinity of boundaries of the outer surface (3C) of the flange (3) than in the vicinity the central portion.

Abstract: An outer peripheral surface (8d) of a bearing sleeve (8) is formed on a radially inside with respect to a first dynamic pressure generation portion (B1). In this case, it is possible to reduce a thickness of the bearing sleeve (8) while securing a first thrust dynamic pressure generating portion (B1) which has a thrust load capacity equivalent to that in a conventional case where a thrust dynamic pressure generating portion is formed in an end surface of the bearing sleeve. Accordingly, it is possible to reduce the thickness of the bearing sleeve (8) without sacrificing a bearing performance in a thrust direction. With this structure, a total amount of a lubricating oil sealed in a bearing device can be reduced, thereby reducing a capacity of a buffering function so as to downsize a sealing portion (9), and by extension, downsizing a fluid dynamic bearing device (1).

Abstract: A system and method are provided for reduced power consumption and reduced wear in a spindle motor. The spindle motor includes a fluid dynamic bearing containing gas defined between a stationary component and a rotatable component. A liquid layer is coated on at least a portion of at least one of the rotatable component surface and the stationary component surface. The liquid layer is formed from a liquid having a predetermined concentration, and formed having a predetermined thickness. The predetermined thickness is accomplished utilizing at least one of a predetermined dwell time, withdraw velocity and bearing surface roughness. In an aspect, the liquid layer is formed with an increased thickness by at least one of increasing the liquid concentration, increasing the dwell time, and increasing the withdraw velocity. In an aspect, a method is provided to obtain thin liquid film thicknesses ranging from about 5 nm to about 350 nm.

Abstract: A fluid bearing that utilizes a variable depth groove is described. The fluid bearing includes two surfaces that are rotatable relative to one another, with a groove on at least one of the surfaces. The floor of the groove is non-constant in depth.

Abstract: A hydrodynamic bearing device includes a rotary part including a shaft and a rotor hub; a stationary part including a bearing member, which has an inner peripheral surface radially confronting with an outer peripheral surface of the shaft, a bearing bore, and an upper surface axially confronting with a bottom surface of the rotor hub; a radial bearing portion formed between the outer peripheral surface of the shaft and the inner peripheral surface of the bearing member; a thrust bearing portion formed between the bottom surface of the rotor hub and the upper surface of the bearing member; and a communication hole having a first end opened radially outwardly at the thrust bearing portion and a second end opened toward a closed side of the first gap, the communication hole being formed at the bearing member.

Abstract: [Problems] Provided is a fluid bearing device in which bearing sleeves are positioned and fixed with respect to a housing with high accuracy. [Solving Means] To an inner periphery of a housing (7), a first bearing sleeve (8) and a second bearing sleeve (9) are fixed while being spaced apart in an axial direction. Between the bearing sleeves (8) and (9), a spacer (10) made of a resin is disposed. An axial rigidity of the spacer (10) is smaller than those of the first bearing sleeve (8) and the second bearing sleeve (9). Accordingly, in a state where the first bearing sleeve (8) and the second bearing sleeve (9) are positioned and fixed with respect to the housing (7), the spacer (10) is largely compressed in an axial direction compared to the bearing sleeves (8) and (9).

Abstract: The invention relates to a spindle motor having a fluid dynamic bearing system used particularly for driving the storage disks of hard disk drives, having a baseplate, a stationary bearing bush disposed in an opening in the baseplate, a shaft rotatably supported in an axial bore in the bearing bush by means of the fluid dynamic bearing system, a hub connected to the shaft, and an electromagnetic drive system. In order to increase the stiffness of the motor system, according to the invention the bearing bush is provided with a flange that is fixed in the opening in the baseplate and whose outside diameter is distinctly larger than the outside diameter of the bearing bush. Instead of a flange at the outer diameter of the bearing bush there can be provided a sleeve at the base plate which receives the bearing bush at least partly.

Abstract: While applying an ultrasonic vibration to a housing 7 and/or a bearing sleeve 8, the outer peripheral surface 8d of the bearing sleeve 8 is press-fitted into the inner peripheral surface 7c of the housing 7 with a predetermined interference, and is welded thereto. During the press-fitting, the region of the inner peripheral surface 7c of the housing 7 coming into contact with the bearing sleeve 8 is melted or softened by the action of the ultrasonic vibration, so that, as compared with a case in which only press-fitting is conducted, the requisite press-fitting force at the time of press-fitting can be substantially reduced.

Abstract: A hydrodynamic bearing device including a sleeve (1), a shaft (2), and oil (100). With respect to the sleeve (1), a stepped portion (1b) provided at one end and an inner peripheral face (1e) extending linearly in the axial direction and continuously with the stepped portion (1b) are formed by a working method that involves the use of a metal mold. The shaft (2) is inserted so as to be capable of relative rotation with respect to the inner peripheral face (1e) of the sleeve (1). The oil fills the space formed between the inner peripheral face of the sleeve and the outer peripheral face of the shaft. Dynamic pressure generation grooves (9a and 9b), which open in the axial direction at at least one end in the axial direction of the inner peripheral face (1e) and are continuous in the axial direction from one end, are formed in the inner peripheral face.

Abstract: A bearing unit includes a radial bearing; a thrust bearing; a path forming member; a housing; viscous fluid; and a communicating path. The communicating path has an axial path formed in the axis direction on a circumferential face of the radial bearing and a second end side path formed on the second end side face of the radial bearing. The second end side path is formed by a plurality of projections formed on one of the second end side face of the radial bearing and a face of the housing opposing to the second end side face of the radial bearing. The cross section of the second end side path has a cross sectional area greater than that of the cross section of the axial path.

Abstract: A fluid dynamic bearing includes a bearing member (30) axially defining an inner bearing hole therein, and a spindle shaft (20) rotatably received in the bearing hole with a bearing clearance formed between an inner periphery of the bearing member and an outer periphery of the spindle shaft. Lubricant is filled in the bearing clearance. One of the inner periphery and the outer periphery comprises a bearing surface (10) with channels formed therein. The channels form a plurality of outer communication ends (1316b) at opposite sides of the bearing surface in the axial direction of the bearing member.

Abstract: Provided is a fluid dynamic bearing device which has excellent moment rigidity and an improved working efficiency in assembling and parts control, and in which a bearing sleeve can be easily manufactured. A plurality of bearing sleeves are axially disposed in the fluid dynamic bearing device. The bearing sleeves (3, 4) are formed with different axial lengths from each other.

Abstract: A fluid dynamic bearing apparatus having an increased a value of tolerance for a moment load is provided. A cylindrical sleeve portion 8 is fixed to the inner periphery of the housing 7 whose both ends are open, and a shaft member 2 is further inserted at the inner periphery of the sleeve portion 8. Sealing portions 9, 10 are fixed to the shaft member 2 in the manner of nipping the sleeve portion 8 from both sides in the axial direction, and sealing spaces S1, S2 having the oil level of a lubricating oil are formed between the outer circumferential surfaces 9a, 10a of the sealing portions 9, 10 and the inner circumferential surface 7a of the housing 7.

Abstract: A bearing unit wherein a radial bearing for bearing a shaft in the circumferential direction of the shaft and a metallic housing provided with an attaching section are integrated with each other by molding, a resin molded body formed by the molding is so formed as to sealingly contain the radial bearing therein and is provided on one end side in the axial direction thereof with a shaft passing hole through which to pass the shaft, and the inside of the resin molded body is filled with a viscous fluid, whereby the viscous fluid such as a lubricating oil can be prevented from leaking, and the bearing unit can be attached to an object easily and assuredly.

Abstract: One preferred embodiment of the present invention provides a motor composed at least of a stator, a rotor, and a dynamic pressure bearing having a thrust dynamic pressure bearing portion and a radial dynamic pressure bearing portion to support the rotor rotatably in relation to the stator, comprising lubrication fluid being filled in a lubrication fluid filled portion connecting said thrust dynamic pressure bearing portion with said radial dynamic pressure bearing portion and being used in common by said thrust dynamic pressure bearing portion and said radial dynamic pressure bearing portion, and a pump-in dynamic pressure generation portion being disposed between said thrust dynamic pressure bearing portion and said radial dynamic pressure bearing portion so as to generate pressure that causes the lubrication fluid to move toward said radial dynamic pressure bearing portion.

Abstract: An inner space of a housing sealed with a seal member as well as internal pores of a bearing member (pores in a porous structure) are filled with a lubricating oil without the presence of air, so that the oil surface of the lubricating oil is within a seal space. Under a reduced pressure of 100 Torr, no lubricating oil leaks outside of the housing even at any attitude of the fluid lubricated bearing device such as normal, inverted, or horizontal attitude.

Abstract: An inner space of a housing sealed with a seal member as well as internal pores of a bearing member (pores in a porous structure) are filled with a lubricating oil without the presence of air, so that the oil surface of the lubricating oil is within a seal space. Under a reduced pressure of 100 Torr, no lubricating oil leaks outside of the housing even at any attitude of the fluid lubricated bearing device such as normal, inverted, or horizontal attitude.

Abstract: The present invention aims to improve the efficiency of a clamping step for combining a flange with a shaft and to improve productivity. The shaft and the flange are tentatively combined in the tentative clamping step. In the tentative clamping step, a concave part at the end of the shaft is pressurized by a metal mold such as a ball to be enlarged in an outer circumferential direction, thereby pressurizing this concave part against the inner circumference of the flange so as to fix the concave part. The combined body made by tentatively combining the shaft and the flange is strongly combined in a proper clamping step. In order to correct a distortion such as a warpage of the flange that has been solidly combined by the proper clamping step, sandwiching the flange by the upper and lower metals, the flange is pressurized and a flash molding is carried out.

Abstract: The bearing system according to the invention comprises a sleeve-shaped first bearing disk having a bore concentric to a rotational axis, a cylindrical shaft disposed in the bore and connected to the first bearing disk, the shaft having a second bearing disk disposed at one end that is arranged at a spacing to the first bearing disk such that an annular disk-shaped space is formed between the first and the second bearing disk. A third annular bearing disk is provided that is disposed in the annular disk-shaped space and is rotatable about the rotational axis, the opposing surfaces of the first, the second and the third bearing disk as well as the shaft being separated from one another by a bearing gap filled with bearing fluid. A radial bearing is provided between the outside circumference of the shaft and the inside circumference of the third bearing disk and marked by the hydrodynamic bearing patterns associated with the circumferential surfaces.

Abstract: The invention relates to a motor lubricant cycling system, wherein a plurality of slots are disposed in the inner wall of the shaft tube in contact with the bearing, one end of the slot is connected to the conjunction of the top side of the bearing and the shaft, the lubricant, due to the pump effect, elevates along the shaft when the motor is rotating at high speed and is sucked in the slot by a backflow suction, and the other end of the slot is connected to the lubricant container beneath the bearing in formation of a guiding path dedicated to the lubricant cycling. According, the lubricant can be recycled for operation so as to reduce the noise resulting from the motor operation and prolong the life cycle.

Abstract: It is an object to improve bearing rigidity in a thrust direction at high temperatures and reduce a torque at low temperatures. An axial member is arranged in such a manner that an outer circumferential surface of an axial part is opposed to an inner circumferential surface of a bearing sleeve with a radial bearing gap interposed therebetween, and both end faces of a flange part are opposed to one end face of the bearing sleeve and a bottom face of a housing with thrust bearing gaps interposed therebetween, respectively. In this manner, the axial member is supported by dynamic pressures generated in the respective bearing gaps in the thrust direction in a non-contact manner. The flange part of the axial member is formed of a resin in such a manner that its linear expansion coefficient in its axial direction is equal to or larger than that of the housing.

Abstract: A device is provided having a support structure and a rotating shaft having a centre axis which rotating shaft and support structure are pivotable supported against each other by at least one hydrodynamic rotary bearing including a first bearing part and a second bearing part pivotable relatively to each other, a lubricant and a contact zone between the first bearing part and the second bearing part at least when the hydrodynamic rotary bearing is at rest, wherein the rotating shaft and the support structure are shaped in such a way and the hydrodynamic rotary bearing is in such a way arranged on the rotating shaft and the support structure that the contact zone of the hydrodynamic rotary bearing is submerged in the lubricant even when the hydrodynamic rotary bearing is at rest.

Abstract: An ultra-thin spindle motor having a groove formed on the outer circumferential surface of a thrust bearing is disclosed. The present invention relates to an ultra-thin spindle motor among small-sized motor using a hydro dynamic pressure generating bearing and its object is to provide a spindle motor capable of stably driving without requiring a sleeve that was required to support a shaft in a radial direction in which a thrust bearing sleeve for coupling a hub and a thrust bearing is constructed and a radial hydro dynamic pressure generating groove is formed on the outer circumferential surface to thereby allow a radial hydro dynamic pressure to be generated and support a thrust bearing sleeve coupled integrally to the hub.

Abstract: A magnet (13) for trapping abraded powder is disposed in a connecting passage between an opening of a sleeve and an opening of a hydrodynamic bearing motor, and a shaft (3), a sleeve (4), a thrust flange (7), and a thrust main plate (5) are made of an austenitic stainless. With this configuration, since the austenitic stainless acting as a nonmagnetic substance is used, it is possible to increase a degree of cleaning. Further, abraded powder of the austenitic stainless is transformed into a magnetic substance, and thus a flow of the abraded powder to the outside can be prevented by providing the magnet for trapping abraded powder in the connecting passage between an opening of a bearing and the outside of the motor.

Abstract: A fluid dynamic-pressure bearing includes a rotatable shaft, a hub, a fixed portion, and a lubricating liquid. The hub includes a hub thrust bearing surface extending from the shaft outwardly in a radial direction and an annular surface. The fixed portion includes a fixed-portion upper thrust bearing surface facing the hub thrust surface and a flange surface facing the annular surface. The hub thrust bearing surface, the fixed-portion upper thrust bearing surface, and the lubricating liquid arranged therebetween form together an upper thrust dynamic-pressure bearing. The annular surface and the flange surface define an annular gap therebetween. An axial dimension of the annular gap is larger than a total of an axial dimension of an upper thrust gap between the hub thrust bearing surface and the fixed-portion upper thrust bearing surface and an average depth of upper thrust dynamic-pressure generating grooves of the upper thrust dynamic-pressure bearing.

Abstract: A fluid lubrication bearing apparatus which can stably produce high bearing performance is provided at low costs. Moreover, a method for producing a housing for hydrodynamic bearing apparatuses which can improve the accuracy of form of the housing of this type at low costs is provided. In forming a housing 7 which has a cylindrical shape and comprises a fixing face 7c for fixing the outer circumferential surface 8b of a bearing sleeve 8, and axial circulation grooves 7d for bringing both end faces 8c, 8d of the bearing sleeve 8 into circulation on the inner periphery by forging, a groove molding portion 18a2 is provided on the outer circumference of a rod 18 which serves as a forming mold for the inner periphery of the housing 7, and the circulation grooves 7d are formed by forging with this groove molding portion 18a2.

Abstract: A bearing includes a hub to drive recording media; a sleeve to rotatably support the hub to define a hydrodynamic pressure generating space between the hub and the sleeve, the sleeve being formed with a fluid outlet through which the fluid passes at the predetermined position; a plurality of recesses to generate hydrodynamic pressure, the recesses being formed on at least one of the hub and the sleeve to be opened toward the hydrodynamic pressure generating space; and a fluid circulating member to circulate the fluid out-flowing from the fluid outlet to the hydrodynamic pressure generating space, the member being fixedly combined with the hub to slidably support the sleeve.

Abstract: A fluid dynamic pressure bearing has an annular dynamic pressure generating face having a dynamic pressure generating groove, which draws a working fluid toward a midway position in the radial direction from the inside and outside of a thrust bearing plate in the radial direction when a shaft and a housing are rotated relative to each other. The dynamic pressure generating groove is provided on thickness direction end faces of the thrust bearing plate or on an inner surface of the housing, and an inner groove section is located on an inner peripheral side of the dynamic pressure generating face on the end faces and is recessed more than the dynamic pressure generating face in the thickness direction. A through-hole extends through the thrust bearing plate in the thickness direction so as to open to the dynamic pressure generating face, and a communicating cavity connects the opening portion of the through-hole and the inner groove section.

Abstract: The fluid dynamic bearing device includes a housing, two bearing sleeves fixed to the housing at positions axially spaced apart from each other, and a shaft member inserted along inner peripheries of the bearing sleeves. The housing includes a spacer portion protruding further radially inwardly than inner peripheral surfaces to which the bearing sleeves are fixed. An axial fluid path is formed in the spacer portion, and the axial fluid path communicates to flow paths formed by axial grooves of the bearing sleeves.

Abstract: A fluid dynamic pressure effect can be sufficient without receiving a large effect of viscous friction of lubricating oil with changes in the environmental temperature in which it is used, and smooth starting of the rotating shaft can be ensured by regulating the gap between the rotating shaft and bearing within a suitable range. An outer diameter of the bearing, D, a length in an axial direction of the bearing, L, a gap at a radial side which is between the rotating shaft and the bearing, C, and an inclining height of the bearing end surface to which the flange is faced, ?, satisfy the expression L/D<C/?. It is preferable that the inclining height, ?, be 2 to 6 ?m, the inner diameter of the bearing be 1 to 3 ?m, and the gap at a radial side, C, be 1 to 4 ?m.

Abstract: A fluid dynamic bearing device is mainly composed of a housing, a bearing sleeve, and a rotary member. The housing is formed by a side portion formed through injection molding of a resin material, and a bottom member fixed to a fixing portion provided in the inner periphery at one axial end of the side portion and adapted to close an opening at one axial end of the side portion. The fixing portion is a molding surface formed through solidification, in conformity with the inner surface of the mold, of the resin injected by the injection molding.

Abstract: A fluid bearing includes hydrostatic pads formed in a surface and positioned to exert a separating force, and a land formed on the surface of the insert and configured to act as a bushing to allow rotation while the first and second pads are pressurized at less than a hydrostatic balance force. Pressurized fluid to the pads of the insert is controlled to prevent operation in full hydrostatic mode. More particularly, a separating force generated by surface force of the pads is controlled such that the separating force does not exceed a force exerted on the bearing. The fluid pressure is also controlled to keep the separating force within a selected margin of the force exerted on the bearing, to control wear of the bearing. Control of the separating force is achieved by selectively pressurizing individual hydrostatic pads, thereby effectively varying the active hydrostatic area of the bearing.

Abstract: A bearing mechanism includes a cylindrical bottom-closed sleeve unit; a shaft unit radially supported by the sleeve unit via a lubricant; and an elastic thrust plate on an inner bottom surface of the sleeve unit to contact an end portion of the shaft unit at a position on a central axis to rotatably support the shaft unit. The shaft unit has a first contact portion, and the sleeve unit has a second contact portion. The contact portions are so arranged that, when a force acting from above the inner bottom surface is applied, movement of the shaft unit is restrained by the contact portions making contact with each other. Further, a distance between the contact portions prior to the force being applied is smaller than the displacement of the shaft unit at which the thrust plate gets so pressed by the shaft unit to be permanently deformed.

Abstract: An exemplary embodiment of a high speed spindle for rotating a tool at high rotational rates includes a hollow spindle body and a cylindrical spindle shaft configured for rotation within the spindle body and having a front end and a rear end. The spindle shaft includes a front hollow region and a rear hollow region. A motor is configured to impart rotational drive forces to the spindle shaft during operation. The spindle shaft includes a thrust bearing flange disposed intermediate the front end and the back end of the spindle shaft. A front air bearing and a rear air bearing are configured to radially support the spindle shaft for high speed rotational movement. A thrust air bearing is disposed between the front air bearing and the rear air bearing within the spindle housing and configured to act on the thrust bearing flange of the spindle shaft to constrain axial movement of the spindle shaft within the spindle housing. A collet is disposed within the front hollow region of the spindle shaft.

Abstract: A fluid dynamic bearing capsule assembly having integral lubricating fluid recirculation paths for insertion into a disc drive hub for a data storage device that eliminates the need for machining recirculation paths directly into the hub.

Abstract: A fluid dynamic bearing device equipped with a shaft member of high strength and capable of maintaining high bearing performance is provided at low cost. A shaft blank (23) has, as an integrated unit, a shaft part (23a) formed of a material of a higher strength than resin, and a protruding part (23b) protruding radially outwards from the shaft part (23a). A shaft member (2) is equipped with the shaft blank (23) and a resin portion (24) covering at least one end surface of the protruding part (23b) of the shaft blank (23) and facing a thrust bearing gap.

Abstract: The present invention aims to achieve a reduction in cost for a fluid dynamic bearing device. The fluid dynamic bearing device supports a shaft member (2) radially in a non-contact fashion by a dynamic pressure action generated in a radial bearing gap between an outer peripheral surface of the shaft member (2) and an inner peripheral surface (7a) of a bearing member (7), and is composed of the shaft member (2), the bearing member (7), a cover member (8), and a seal member (9). The shaft member (2) is inserted into an inner periphery of the bearing member (7), and an opening at a lower end thereof is sealed by the cover member (8). The seal member (9) is attached to an opening at an upper end of the bearing member (7), forming a seal space (S) between itself and the outer peripheral surface of the shaft member (2). Dynamic pressure grooves (G) of radial bearing portions (R1 and R2) are formed in an inner peripheral surface (7a) of the bearing member (7) by molding.

Abstract: A fluid bearing device capable of responding to miniaturization while preventing an operating fluid such as a lubricating oil from leaking out to the outside. The fluid bearing device includes a shaft and a sleeve arranged on an outer periphery with respect to the shaft with a microscopic gap in between, and has an operating fluid filled in between the shaft and the sleeve. The shaft is formed by a sintered body, a radial dynamic pressure generating groove is formed on an outer peripheral surface of the shaft, and the sleeve is formed by a material not allowing the operating fluid to pass through. The shaft is thus covered by the sleeve formed by a material that does not penetrate the operating fluid such as lubricating oil from the outer periphery side, so that the operating fluid does not leak out to the outside even when the shaft is a porous body made of a sintered body.

Abstract: A hydrodynamic bearing device (30) comprises a shaft (31), a sleeve (32) in which the shaft (31) is installed so as to be able to rotate in relative fashion, a lubricant (34) filled into a minute gap between the shaft (31) and the sleeve (32), a sleeve cover (35) attached to the upper end surface of the sleeve (32), a lubricant reservoir (50) for retaining the lubricant (34) between the sleeve (32) and the sleeve cover (35), and flow suppressing parts (51a, 51b) formed inside the lubricant reservoir (50) so as to protrude in an axial direction.

Abstract: A hydrodynamic bearing type rotary device which allows bubbles in a lubricating fluid to be surely discharged from a bearing portion is provided. A hydrodynamic bearing mechanism 40 of the hydrodynamic bearing type rotary device is formed of a sleeve 1, a shaft 2, a flange 3, a thrust plate 4, a seal cap 5, and oil 6. A first fluid reservoir F is formed between the sleeve 1, the flange 3, and the thrust plate 4. A second fluid reservoir H is formed between the sleeve 1 and the seal cap 5. In the sleeve 1, a communication hole G extending along an axial direction is formed. The first fluid reservoir F and the second fluid reservoir H communicate with each other through the communication hole G. The oil 6 is filled between the members. A capillary pressure is higher in the first fluid reservoir F than in the second fluid reservoir H.