Abstract: A robotic surgical tool includes a drive housing having a first end, a second end, and a lead screw extending between the first and second ends, a carriage movably mounted to the lead screw at a carriage nut secured to the carriage, and an elongate shaft extending from the carriage and extending through the first end, the shaft having an end effector arranged at a distal end thereof. Rotation of the lead screw moves the carriage and the carriage nut axially between the first and second ends and thereby moves the end effector distally or proximally.

Abstract: A bearing device includes a rotary part which is configured to be rotatable about a rotational axis and has a rotary surface intersecting the rotational axis, and a stationary part which has a stationary surface facing the rotary surface. One of the rotary surface or the stationary surface includes a bearing surface part for forming a bearing oil film. The rotary surface includes a first inner circumferential region, and a first outer circumferential region facing the stationary surface on a radially outer side of the bearing surface part and having higher oleophobicity than the first inner circumferential region.

Abstract: Embodiments of the invention relate to bearing apparatuses in which one bearing surface of the bearing apparatus includes diamond, while another bearing surface includes a non-diamond superhard material (e.g., silicon carbide). For example, a bearing apparatus may include a bearing stator assembly and a bearing rotor assembly. The bearing stator assembly and bearing rotor assembly each include a support ring and one or more superhard bearing elements generally opposed to one another. The bearing surface(s) of the rotor or stator may include diamond, while the bearing surface(s) of the other of the rotor or stator do not include diamond. Another bearing apparatus may include both thrust- and radial bearing components. The generally opposed thrust-bearing elements may include diamond, while the generally opposed radial bearing elements may not include diamond, but include a non-diamond superhard material, such as silicon carbide.

Abstract: The present disclosure relates to a flywheel system. The flywheel system comprises a rotation axis and a flywheel rotor connected to the rotation axis. Further, the system comprises a drive and/or a power generator connected to the flywheel rotor. According to the invention, the flywheel rotor has an outer radius in radial direction of at least 0.85 meter, preferably at least meter, and more preferably at least 1.30 meter. The invention further relates to flywheel rotors having a thickness in axial direction of at least 0.30 meter, preferably at least 0.45 meter, and more preferably at least 0.60 meter. Finally, the invention also relates to a flywheel system of which the rotor has a weight of at least 2.5 tons, preferably at least 4 tons and more preferably at least 5 tons.

Abstract: A lubrication system includes a pair of mating surfaces subject to relative motion and a source of lubrication in communication with the mating surfaces. A microfluidic channel system including at least one diffuser element is disposed in an interface between the mating surfaces to create a coherent fluid film at the interface in response to the relative motion.

Abstract: A system includes a hydraulic energy transfer system configured to exchange pressures between a first fluid and a second fluid, wherein the first fluid has a pressure higher than the second fluid. The hydraulic transfer system includes a cylindrical rotor configured to rotate circumferentially about a rotational axis and having a first end face and a second end face disposed opposite each other, a first end cover having a first surface that interfaces with the first end face of the cylindrical rotor, and a hybrid hydrodynamic-hydrostatic bearing system configured to resist axial displacement of the cylindrical rotor.

Abstract: A scroll compressor is provided that may include an orbiting scroll having an orbiting wrap, and which performs an orbiting motion; and a fixed scroll having a fixed wrap to form a compression chamber including a suction chamber, an intermediate pressure chamber, and a discharge chamber, by being engaged with the orbiting wrap. In a state in which the orbiting scroll and the fixed scroll are concentric with each other, when a distance between the orbiting wrap and the fixed wrap is defined as an orbiting radius, there exists an offset section having an interval larger than the orbiting radius, between a side surface of the orbiting wrap and a side surface of the fixed wrap which faces the orbiting wrap. With such a configuration, even if the fixed scroll or the orbiting scroll is transformed due to thermal expansion, interference between the fixed wrap and the orbiting wrap at a portion having a large transformation amount may be prevented.

Abstract: Provided is a semi-annular-shaped half thrust bearing having a sliding surface for receiving an axial force and a back surface opposite to the sliding surface. The sliding surface includes a plurality of recesses. Each recess has a recess surface recessed from the sliding surface toward the back surface of the half thrust bearing. The recess surface is convex toward the back surface of the half thrust bearing in cross-sectional view in a circumferential direction of the half thrust bearing. The recess surface includes a plurality of circumferential grooves recessed from the recess surface toward the back surface of the half thrust bearing. The circumferential grooves extend along the circumferential direction of the half thrust bearing, and smooth surfaces and the circumferential grooves are alternately arranged on the recess surface.

Abstract: An axial bearing may include a body having a disk-form configuration, a centrally disposed passage opening extending axially into the body structured to receive a shaft, and at least one circular segmental oil pocket opening towards the passage opening. The at least one oil pocket, in both circumferential directions relative to the body, may transition into a plateau surface section directly adjoining the at least one oil pocket.

Abstract: One aspect of the invention relates to a pump device comprising an impeller; a pump housing surrounding an interior region and having an inlet and an outlet. The impeller is provided in the interior region of the pump housing. The wall of the pump housing has at least one first subregion and at least two further subregions in at least one plane perpendicular to the longitudinal extension of the pump housing. The at least one first subregion comprises at least 60% by weight, based on the total mass of the at least one first subregion, of at least one nonmagnetic material. The further subregions comprise at least 41% by weight, based on the total mass of the further subregions, of at least one ferromagnetic material, wherein each further subregion is adjacent to at least one first subregion in the plane.

Abstract: A half thrust bearing includes a sliding surface for receiving an axial force of a crankshaft of an engine, and a rear surface on an opposite side thereto. The sliding surface includes a flat surface portion near a circumferentially central portion, and two inclined flat surface portions on both circumferential sides of the flat surface portion. The axial distance between the rear surface and the sliding surface is maximum at the flat surface portion. At any radial positions, the axial distance in each inclined flat surface portion is maximum on a circumferentially central portion side and is reduced toward a circumferential end portion of the half thrust bearing. Each inclined flat surface portion is arranged to form one constant thickness portion extending linearly from a radially inner end to a radially outer end at a circumferential angle of 45°.

Abstract: In an embodiment, a sliding face of at least one sliding part of the pair of sliding parts is provided, along its entire circumference, with a trap groove 10 for trapping leakage fluid, located on a leakage side and spaced from the leakage side by a land. A dust entry reduction means 12 for reducing entry of dust from the leakage side while allowing passage of fluid is formed between lands of the pair of sliding parts on the leakage side of the trap groove 10. At the sliding faces of the pair of sliding parts sliding relatively, entry of dust from the leakage side as well as liquid leakage to the leakage side are suppressed.

Abstract: A fluid bearing apparatus includes a stationary member and a rotating member. A bearing surface of the stationary member and a bearing surface of the rotating member are arranged opposite to each other with a minute gap therebetween. The minute gap has a fluid arranged therein. At least one of the bearing surfaces includes a first dynamic pressure groove array. The first dynamic pressure groove array includes a plurality of first dynamic pressure grooves arranged unevenly at irregular intervals in a circumferential direction.

Abstract: A thrust bearing for receiving an axial force of a crankshaft of an internal combustion engine. The thrust bearing includes a pair of half thrust bearings having a semi-annular shape that form an annular shape by abutting their circumferential end surfaces. Each half thrust bearing include thrust reliefs formed adjacent to both circumferential end portions of a sliding surface receiving the axial force so that a wall thickness is thinner toward the circumferential end surface. A thrust relief length L2 at an inner end portion of the thrust relief positioned on a rear side of one of the half thrust beings in a rotational direction is larger than a thrust relief length L1 at an inner end portion of the thrust relief positioned on a front side of the other of the half thrust bearing in the rotational direction.

Abstract: A bearing device, including a crankshaft, a pair of half bearings each having crush reliefs formed adjacent to both circumferential ends thereof, a bearing housing in which a retaining hole is formed for retaining the pair of half bearings, and one half thrust bearing having a semi-annular shape arranged adjacent to the retaining hole. The half thrust bearing includes thrust reliefs formed adjacent to both circumferential end portions of a sliding surface receiving an axial force of the crankshaft so that its wall thickness is made thinner toward the circumferential end surface, and a thrust relief length at an inner end portion of the thrust relief positioned on a rear side in the crankshaft rotational direction is formed to be larger than a thrust relief length at an inner end portion of the thrust relief positioned on a front side in the crankshaft rotational direction.

Abstract: Various “contactless” bearing mechanisms including hydrodynamic, hydrostatic, and magnetic bearings are provided for a rotary pump as alternatives to mechanical contact bearings. These design features may be combined. In one embodiment, the pump apparatus includes a rotor having a bore, a ring-shaped upper rotor bearing magnet, and a ring-shaped lower rotor bearing magnet. The bearing magnets are concentric with the bore. The lack of mechanical contact bearings enables longer life pump operation and less damage to working fluids such as blood.

Abstract: A centrifugal blood pump apparatus includes an impeller provided in a blood chamber, first and second permanent magnets provided in one surface and the other surface of the impeller respectively, a third permanent magnet provided in an inner wall of the blood chamber, and a magnetic element and a coil for driving the impeller to rotate with a diaphragm being interposed. First and second grooves for hydrodynamic bearing different in shape and depth from each other are formed in the inner wall of the blood chamber facing the impeller, and third and fourth grooves for hydrodynamic bearing different in shape and depth from each other are formed in the diaphragm facing the impeller. The second and fourth grooves for hydrodynamic bearing generate high hydrodynamic pressure when the impeller is activated to rotate, while the first and third grooves for hydrodynamic bearing generate high hydrodynamic pressure when the impeller steadily rotates.

Abstract: A positive pressure generating mechanism comprising a positive pressure generating groove is provided to a high-pressure side of one of two sliding surfaces that slide relative to each other in a pair of sliding components, and a negative pressure generating mechanism comprising a negative pressure generating groove is provided to a low-pressure side. The positive pressure generating groove and negative pressure generating groove are communicated with a high-pressure fluid side and separated from a low-pressure fluid side by a seal surface.

Abstract: A positive pressure generating mechanism comprising a positive pressure generating groove is provided to a high-pressure side of one of two sliding surfaces that slide relative to each other in a pair of sliding components, and a negative pressure generating mechanism comprising a negative pressure generating groove is provided to a low-pressure side. The positive pressure generating groove and negative pressure generating groove are communicated with a high-pressure fluid side and separated from a low-pressure fluid side by a seal surface.

Abstract: Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

Abstract: Provided herein is an apparatus, including an inner component, wherein the inner component includes a thrust plate; an outer component, wherein the inner component and the outer component are positioned for relative rotation, and wherein the inner component and the outer component are positioned to form at least one bearing having a groove pattern that imparts a predetermined direction to the rotational motion of the inner component and the outer component; and a gas inlet operable to receive a pressurized gas.

Abstract: A sliding component is characterized in that: with respect to a pair of sliding parts that slide relative to each other, one sealing face has a fluid circulation groove including an inlet through which fluid enters from the high-pressure fluid side, an outlet through which fluid is released to the high-pressure fluid side, and a communicating part through which the inlet and outlet communicate with each other; wherein the fluid circulation groove is isolated from the low-pressure fluid side by a land, a positive-pressure generation mechanism is provided in the area surrounded by the fluid circulation groove and high-pressure fluid side, and the positive-pressure generation mechanism communicates with the inlet and is isolated from the outlet and high-pressure fluid side by a land.

Abstract: Provided herein is an apparatus, including a stationary component and a rotatable component; a fluid between the stationary component and the rotatable component; a limiter shoulder of the stationary component; a flanged limiter bushing of the rotatable component; and a separating means for separating the limiter shoulder and the limiter bushing, wherein the separating means comprises the fluid.

Abstract: The invention relates to an axial bearing comprising a slide ring (1), a counter-ring (2) and an elastic mounting (3) of the slide ring, wherein the slide ring (1) is integral and has a structuring on the running surface thereof which enables the development of a stable, hydrodynamic lubricating film and wherein the structuring of the running surface occurs so that the running surface has three or more elevations (6), wherein the contact surfaces (8) thereof are even with the counter-ring (2).

Abstract: Embodiments of a thrust bearing that may be used with a crankshaft of a HVAC compressor, particularly a HVAC compressor with a vertical or near-vertical placed crankshaft (e.g. a scroll compressor) are provided. The thrust bearing may generally include a bearing header and an insert. The insert may include an insert surface, which is configured to interact with a shaft surface of the crankshaft. The insert surface of the insert may include surface features that may help create flow behavior of the lubricant by a relative motion between the shaft surface of the crankshaft and the insert surface of the insert. The flow behavior of the lubricant may help separate the insert surface of the insert and the shaft surface of the crankshaft by the lubricant in operation to form the bearing, such as a hydrodynamic bearing.

Abstract: It is an object of the present invention to provide a bearing member having a highly accurate dynamic pressure generating portion stably at low cost. Dynamic pressure grooves (8a1) and (8a2) are formed as the dynamic pressure generating portions on an inner circumferential surface of the electroforming portion (10) by an electroforming process, and injection molding is performed by using a resin while inserting the electroforming portion (10), thereby forming a bearing member (8). A shaft member (2) is inserted into an inner circumference of the bearing member.

Abstract: An inner peripheral surface and a lower end surface of a bearing sleeve made of a sintered metal are each formed into a smooth cylindrical surface or a flat surface that does not have a dynamic pressure generating portion. Thus, a step of forming the dynamic pressure generating portion can be omitted from a manufacturing step of the bearing sleeve, and cost of dies can be markedly reduced. Further, the inner peripheral surface of the bearing sleeve is formed into the smooth cylindrical surface, and hence a radial dynamic pressure generating portion is formed on an outer peripheral surface of a shaft member. However, the outer peripheral surface of the shaft portion is accessible to tools, and hence the radial dynamic pressure generating portion can be formed easily with high accuracy. As a result, accuracy of a radial bearing gap is enhanced so that a bearing rigidity is enhanced.

Abstract: Provided herein is an apparatus, including a fluid dynamic bearing, wherein the fluid dynamic bearing includes a set of pressure-generating grooves, and wherein the set of pressure-generating grooves includes a plurality of chevron-shaped grooves, each chevron-shaped groove including at least two selected from a non-uniform depth, non-uniform angle, a non-uniform width, or a non-uniform length, selected to provide a predetermined spindle-motor stiffness to the journal bearing during steady-state operation and during a shock event.

Abstract: A bearing assembly system adapted for use on a rock crusher having a main frame, a main shaft, an eccentric and a crashing bead, The bearing assembly system comprises a first bearing ring which is disposed around the main shaft, a second bearing ring which is disposed adjacent to the first bearing ring, and a means for conveying fluid to at least one of the first bearing ring and the second bearing ring, in the preferred bearing assembly system at least one of the first bearing ring and the second bearing ring comprises a fluid depression, The preferred method farther comprises conveying fluid from the means for conveying fluid to at least one of the first bearing ring and second bearing ring.

Abstract: Provided herein, is an apparatus that includes a fluid dynamic bearing defined in a gap between a stationary component and a rotatable component. The fluid dynamic bearing includes a first portion of the gap at an axial end of the fluid dynamic bearing, and a second portion of the gap. The first portion of the gap is narrower than the second portion of the gap. A groove in the fluid dynamic bearing on the stationary component or the rotatable component includes a portion of a predetermined width or a predetermined depth. The portion of the predetermined width or predetermined depth is selected based on the first gap or the second gap.

Abstract: A gas bearing (100) having pressurized axially extending chambers (110) in a housing (102) having a shaft bore (104) therein, the axially chambers (110) being in fluid communication with a bearing surface (108) that defines the bore via laser-drilled capillaries (118). The end (122) of each laser-drilled capillary at the bearing surface (108) is flared such that the narrowest portion of the capillary is set back from the bearing surface (108). This shape can ensure that the load carrying function of the bearing (100) does not fail during shaft eccentricity by ensuring that pressure restriction must happen within the capillary and not the gap being shaft and bearing surface. The bearing surface may face in an axial and/or radial direction with respect to the shaft. The axial chambers may be pressurized axially such that the outer circumference of the housing is unbroken and hence usable for other purposes.

Abstract: A positive pressure generating mechanism comprising a positive pressure generating groove is provided to a high-pressure side of one of two sliding surfaces that slide relative to each other in a pair of sliding components, and a negative pressure generating mechanism comprising a negative pressure generating groove is provided to a low-pressure side. The positive pressure generating groove and negative pressure generating groove are communicated with a high-pressure fluid side and separated from a low-pressure fluid side by a seal surface.

Abstract: An axial sliding bearing has a sliding ring disposed between two planar, ring-shaped sliding surfaces pressure-stressed against one another. The axial sliding bearing is overload-proof, in particular by about 30% to 80% with regard to the average pressure stress of about 30 to 40 bar per wedge segment that is usual in the case of wedge segment bearings, and at the same time, is not susceptible to axial vibrations, and, in this connection, can be easily produced in terms of production technology, and easily installed, and furthermore does not permit the “snap-over effects” that drastically impair the lubricant wedge effect, so that even under more difficult operating conditions, targeted optimal variation of the wedge angle, adapted to the operating conditions, in each instance, is always guaranteed, and great reliability of the axial sliding bearing, at a long useful lifetime, can be guaranteed, while simultaneously expanding the optimal dynamic supporting range.

Abstract: Provided herein is an apparatus, including an inner component, wherein the inner component includes a thrust plate; an outer component, wherein the inner component and the outer component are positioned for relative rotation, and wherein the inner component and the outer component are positioned to form at least one bearing having a groove pattern that imparts a predetermined direction to the rotational motion of the inner component and the outer component; and a gas inlet operable to receive a pressurized gas.

Abstract: There are provided a spindle motor and a hard disk drive including the same. The spindle motor includes a sleeve fixedly installed on a base member and including a circulation hole formed in an axial direction; a shaft rotatably inserted into the sleeve; a rotor hub fixedly installed on an upper end portion of the shaft; and a thrust member installed in an installation groove formed in an upper portion of the sleeve in the axial direction and forming a connection part allowing the circulation hole to be in communication with a sealing part formed by the sleeve and the rotor hub and having a liquid-vapor interface, wherein the connection part is formed between the sleeve and the thrust member in a circumferential direction, and a gap on any one side of the connection part in a radial direction is larger than a gap on the other side thereof.

Abstract: A positive pressure generating mechanism comprising a positive pressure generating groove is provided to a high-pressure side of one of two sliding surfaces that slide relative to each other in a pair of sliding components, and a negative pressure generating mechanism comprising a negative pressure generating groove is provided to a low-pressure side. The positive pressure generating groove and negative pressure generating groove are communicated with a high-pressure fluid side and separated from a low-pressure fluid side by a seal surface.

Abstract: A positive pressure generating mechanism comprising a positive pressure generating groove is provided to a high-pressure side of one of two sliding surfaces that slide relative to each other in a pair of sliding components, and a negative pressure generating mechanism comprising a negative pressure generating groove is provided to a low-pressure side. The positive pressure generating groove and negative pressure generating groove are communicated with a high-pressure fluid side and separated from a low-pressure fluid side by a seal surface.

Abstract: There are provided a spindle motor and a hard disk drive including the same. The spindle motor includes: a sleeve installed on a base member and having a circulation hole; a shaft inserted into the sleeve; a rotor hub installed on an upper end portion of the shaft; and a thrust member installed in an installation groove formed in an upper portion of the sleeve and forming a connection part, the connection part allowing the circulation hole to be in communication with a sealing part formed by the sleeve and the rotor hub and having a liquid-vapor interface disposed therein, wherein the connection part is formed between the sleeve and the thrust member in a circumferential direction, and at least any one part of the connection part has a radial gap wider than that of another part thereof in the circumferential direction.

Abstract: A hydrodynamic axial bearing for mounting a shaft which is mounted rotatably in a bearing housing, including an axial stop of the bearing housing and a bearing comb which rotates with the shaft. A lubricating gap, which is loaded with lubricating oil and is delimited by a profiled circular ring face and a sliding face, being formed between the axial stop and the bearing comb. The profiled circular ring face and the sliding face are configured in such a way that the lubricating gap is constricted radially to the outside with regard to the axial direction. As a result, temperature deformations which occur during operation and deformations on account of centrifugal, shearing and other forces in the bearing comb can be compensated for.

Abstract: A positive pressure generating mechanism comprising a positive pressure generating groove is provided to a high-pressure side of one of two sliding surfaces that slide relative to each other in a pair of sliding components, and a negative pressure generating mechanism comprising a negative pressure generating groove is provided to a low-pressure side. The positive pressure generating groove and negative pressure generating groove are communicated with a high-pressure fluid side and separated from a low-pressure fluid side by a seal surface.

Abstract: A thrust bearing device is constituted by a turbine-side thrust collar and a compressor-side thrust collar that are fixed to a rotary shaft; and a thrust bearing that is arranged between the thrust collars. The thrust bearing is provided with an oil passage that supplies lubricating oil r to sliding-contact surfaces formed between the thrust bearing and the thrust collars. The outsides of the thrust collars in a radial direction incline toward the thrust bearing side. A gap c between the sliding-contact surfaces is narrowed as the gap goes outward in the radial direction, and establishes a basic region gap (c1)>an outer peripheral end gap (c2). The lubricating oil outflow resistance of a radial outer region of the gap c becomes larger than that of a radial inner region. Therefore, the lubricating oil r can be kept from flowing out from a radial outer outlet.

Abstract: A brake caliper of a disk brake, includes a housing having a bore hole, in which an axially displaceable piston is arranged, and a shaft for actuation, which is supported so that it is rotatable and axially displaceable in the housing, and an adjusting device having a spindle to compensate for brake lining wear, an axial bearing being provided between the spindle and the shaft. For an improved wear resistance, it is proposed according to the invention that the axial bearing be integrally formed from a homogeneous material matrix.

Abstract: A component for use in a bearing device according to one embodiment of the present invention includes a lubricant layer on a surface of the component. Here, the lubricant layer contains a rod-like ionic liquid crystal compound having a cation group and an anion group.

Abstract: A thrust system for a watercraft including a propeller shaft, a propeller shaft housing and a hydraulic thrust bearing assembly. The propeller shaft has an enlarged diameter shoulder, and the housing is positioned around and allows axial movement of the propeller shaft. The hydraulic thrust bearing assembly is axially constrained between the propeller shaft shoulder and the housing. The hydraulic thrust bearing assembly includes an annular cylinder, an annular piston, at least one oil feed passage and at least one oil bleed port. The annular cylinder surrounds the propeller shaft and has a circular groove. The annular piston surrounds the propeller shaft and is movably positioned within the circular groove of the annular cylinder forming a pressurized chamber. Each oil feed passage and oil bleed port allows oil to be communicated relative to the pressurized chamber. The hydraulic pressure developed in the pressurized chamber is proportional to thrust.

Abstract: A thrust-bearing (1) disposed to face a thrust collar provided on a rotary shaft, including: grooves (5) formed at a bearing-surface (4b); a first-groove-group (6A) constituted by a plurality of first-spiral-grooves (6) formed at an inner circumferential side of the bearing-surface (4b); a second-groove-group (7A) constituted by a plurality of second-spiral-grooves (7) formed at an outer circumferential side more than the first-groove-group (6A) and wound in the same direction as the first-spiral-groove (6); and an annular-land-section (8) formed at the side, to which a fluid is drawn, among the inner circumferential more than the first-groove-group (6A) and the outer circumferential more than the second-groove-group (7A), wherein some of the first-spiral-grooves (6) of the first-groove-group (6A) and some of the second-spiral-grooves (7) of the second-groove-group (7A) are in communication with each other via a partial-communication-section (11), at least one side of which is in partial communication with th

Abstract: A rotary supply joint that may, in particular be a rotary timing valve, is provided for providing fluid flow at least periodically from inlet ports to outlet ports when respective openings in first and second surfaces which are rotating relative to each other are aligned, in which a gas bearing is arranged to provide a bearing force between the first and second surfaces.

Abstract: A typical dynamic bearing design comprises a ring shaped or circular thrust plate mounted at or near the end of a shaft, the shaft defining together with a surrounding sleeve a journal bearing by providing grooves on only one of the two surfaces facing the gap between the shaft and sleeve. On the ring shaped thrust plate supported by the shaft, the traditional upward thrust bearing defined between the lower face of the thrust plate and the facing surface of the sleeve is maintained; but no grooves are on the surface of the thrust plate distant from the shaft and a facing counterplate surface. Further, the journal bearing is defined to have an asymmetry so that a bias force pressure along the surface of the shaft toward the thrust plate is established.

Abstract: Provided herein is an apparatus, including a fluid dynamic bearing, wherein the fluid dynamic bearing includes a set of pressure-generating grooves, and wherein the set of pressure-generating grooves includes a plurality of chevron-shaped grooves, each chevron-shaped groove including at least two selected from a non-uniform depth, non-uniform angle, a non-uniform width, or a non-uniform length, selected to provide a predetermined spindle-motor stiffness to the journal bearing during steady-state operation and during a shock event.

Abstract: Disclosed herein is a spindle motor including a rotating part in which a hub is coupled to a rotating shaft and a fixing part in which a sleeve is coupled to the rotating shaft, wherein the rotating shaft has a thrust hydrodynamic bearing part formed on a lower end thereof, and the thrust hydrodynamic bearing part has a scroll groove formed therein. The thrust hydrodynamic bearing part of the spindle motor is formed in a micro-gap between a lower portion of the rotating shaft and an upper portion of a support to reduce frictional force, thereby making it possible to increase efficiency in power consumption, assembling accuracy is mitigated, thereby making it possible to increase a degree of freedom in design, the scroll groove is formed in the thrust hydrodynamic bearing part, thereby making it possible to solve problems of rotation unbalance and dynamic pressure unbalance.

Abstract: An axial bearing between a first part and a second part that presses with an axial load against the first part and can rotate around a rotation axis relative to the first part comprising a circular or arc-shaped ridge on the first part centered around the rotation axis, a pressure source for providing pressurized hydraulic fluid on a first side of the circular or arc-shaped ridge, an adjustable gap between the circular or arc shaped ridge and a bearing surface on the second part, wherein the pressurized hydraulic fluid flows through the adjustable gap to a second side of the circular or arc-shaped ridge. In accordance with the invention the circular or arc-shaped ridge or the bearing surface include a ridge chamber for locally creating a larger adjustable gap between the circular or arc-shaped ridge and the bearing surface.