Abstract: A hydrodynamic bearing device which supports a relative-rotation shaft or bearing by the hydrodynamic pressure of lubricating fluid which develops in a clearance between the bearing and the shaft, wherein leakage of the lubricating fluid to the outside of the bearing is satisfactorily prevented by a simple arrangement.

Abstract: A motor that can obtain a sufficient magnetic attraction force by a magnetic attraction member with a relatively simple and small structure is provided. The motor includes a stator section, a rotor section that is rotatably supported through a bearing section by the stator section, a rotor magnet disposed opposite to the stator core, and a magnetic attraction member that is disposed opposite to a circumferential wall surface of the rotor magnet in a radial direction to magnetically attract the rotor section toward the stator section by a magnetic action between the rotor magnet and the magnetic attraction member. The magnetic attraction member includes a generally cylindrical member that is disposed concentrically with the rotor magnet, wherein an outer circumferential wall surface of the generally cylindrical member of the magnetic attraction member is disposed opposite to an inner circumferential wall surface of the rotor magnet.

Abstract: A dynamic pressure bearing device includes a dynamic pressure bearing member that generates a dynamic pressured by pressurizing a lubrication fluid by a dynamic pressure generation device, and supports a rotary shaft by the dynamic pressure generated in the lubrication fluid, a thrust dynamic pressure bearing member formed by an end face in an axial direction of the dynamic pressure bearing member and an end face in an axial direction of a rotary member that rotates together with the rotary shaft, which are disposed opposite each other in the axial direction, and a fluid sealing section for preventing the lubrication fluid in the thrust dynamic pressure bearing member from leaking outside, provided adjacent to an outer side section in a radial direction of the thrust dynamic pressure bearing member and defined by an outer circumference wall surface of the dynamic pressure bearing member.

Abstract: A dynamic pressure bearing device includes a dynamic pressure bearing member, a rotary member that is rotatable with respect to the dynamic pressure bearing member, a thrust dynamic pressure bearing section provided in a thrust opposing region that is between an end surface in an axial direction of the dynamic pressure bearing member and an end surface in the axial direction of the rotary member, and a pumping device provided in the thrust opposing region. The thrust dynamic pressure bearing section rotatably supports the rotary member in the axial direction of the rotary member, and the pumping device provided in the thrust opposing region pressurizes a lubricating fluid inside the thrust opposing region inwardly in a radial direction, wherein the pumping device generates an inward pressurizing force larger than a rotational centrifugal force applied to the lubricating fluid within the thrust opposing region during rotation.

Abstract: A motor includes a stator core mounted to a base frame and includes salient pole sections extending radially from the stator core and each of the plurality of salient pole sections is provided with stator coils wound around each of the salient pole sections. The motor also includes a sheet-shaped flexible circuit board that has a flexible main body portion provided with land portions to which each of the terminal portions of the stator coils is electrically connected. The flexible main body portion of the flexible circuit board is provided with elastic extending portions extending between the salient pole sections, the land portion is formed on each of the elastic extending portions, the elastic extending portion is bent by the flexible main body portion being mounted to the fixed member, and each of the land portions of the elastic extending portions is pushed against the fixed member by the elastic force due to the bending.

Abstract: A method for manufacturing a dynamic pressure bearing device is provided. The dynamic pressure bearing device includes a bearing member and a shaft member rotatably disposed with respect to one another, and a thrust plate mounted on the shaft member and a counter plate fixed to the bearing member disposed opposite to one another to compose a thrust dynamic pressure bearing section. According to the method, a through hole that communicates with both ends of the shaft member in an axial direction thereof is formed in the shaft member, and a female screw section is formed in an inner wall section of the through hole such that screw members can be screwed from the both ends of the through hole of the shaft member. One of the screw members is screwed in the through hole of the shaft member from one end of the shaft member. The screw member has a screw head section and a male screw section extending from the screw head section for threaded engagement with the female screw section.

Abstract: A pair of thrust hydrodynamic bearing portions are made to communicate with each other to form fluid circulating passages for equalizing a pressure imbalance between both thrust hydrodynamic bearing portions.

Abstract: A stacked layered core includes a core body formed from a plurality of core, plates stacked in layers, each of the core plates having a connection base section formed in a circular shape and a plurality of salient pole sections radially extending from an external peripheral surface or an internal peripheral surface of the connection base. The circular connection base section has a fixing-side peripheral surface on the opposite side of the salient pole sections. At least one retaining recessed section is provided in the fixing-side peripheral surface of the connection base section. A dielectric film may be formed over an external surface of the core body. The retaining recessed section has a depth greater than a thickness of a bump portion of the dielectric film formed in the retaining recessed section such that the bump portion of the dielectric film is contained inside the retaining recessed section.

Abstract: A fluid dynamic pressure bearing apparatus includes a radial dynamic pressure bearing formed in a gap portion between a bearing member and a shaft member. The apparatus also includes a thrust dynamic pressure bearing having a first thrust bearing portion formed between a top surface of the thrust plate and a first facing member opposing thereto in the axial direction and a second thrust bearing portion formed between a bottom surface of the thrust plate and a second facing member opposing thereto in an axial direction. Dynamic pressure generating grooves are formed on the radial dynamic pressure bearing and the thrust dynamic pressure bearing.

Abstract: A motor includes a stator core mounted to a base frame and includes salient pole sections extending radially from the stator core and each of the plurality of salient pole sections is provided with stator coils wound around each of the salient pole sections. The motor also includes a sheet-shaped flexible circuit board that has a flexible main body portion provided with land portions to which each of the terminal portions of the stator coils is electrically connected.

Abstract: A dynamic pressure bearing apparatus has a rotatable shaft to which a hub is mounted, a disk fixed to the hub, a sleeve which supports the rotatable shaft, and a dynamic pressure bearing formed between the rotatable shaft and the sleeve. The rotatable shaft is rotatably supported by the dynamic pressure bearing. The dynamic pressure bearing apparatus is manufactured by integrating the hub and the rotatable shaft by fixing the hub and shaft to each other, processing the disk mounting surface of the hub after integration, such that relative accuracy between the rotatable shaft and the disk mounting surface can be obtained, and then assembling the rotatable shaft to the sleeve.

Abstract: In a dynamic pressure bearing device which has a shaft (3), a bearing (10) rotatable relative to the shaft (3), and capillary seal portions (13, 14) for holding a lubricating fluid (15) in a bearing clearance and in which the shaft (3) and the bearing (10) are relatively rotatably supported by dynamic pressure of the lubricating fluid (15) in the bearing clearance is scattered by centrifugal force so that the lubricating fluid (15) is kept in a constant quantity by the capillary seal portions (13, 14).

Abstract: A stacked layered core includes a core body formed from a plurality of core plates stacked in layers, each of the core plates having a connection base section formed in a circular shape and a plurality of salient pole sections radially extending from an external peripheral surface or an internal peripheral surface of the connection base. The circular connection base section has a fixing-side peripheral surface on the opposite side of the salient pole sections. At least one retaining recessed section is provided in the fixing-side peripheral surface of the connection base section. A dielectric film may be formed over an external surface of the core body. The retaining recessed section has a depth greater than a thickness of a bump portion of the dielectric film formed in the retaining recessed section such that the bump portion of the dielectric film is contained inside the retaining recessed section.

Abstract: A potential-difference alleviating member for alleviating and lowering the potential difference, which is an energy difference between a rotating or fixed bearing member and a rotary hub or a fixing frame which are formed of metals of different types, is interposed between the two members so as to prevent the occurrence or advance of potential difference corrosion. Relief portions are respectively provided at a joining interface between a rotary shaft and a thrust plate and a joining interface between a bearing member and the counter plate, and the respective members are welded in the relief portions so as to be integrated.

Abstract: A potential-difference alleviating member for alleviating and lowering the potential difference, which is an energy difference between a rotating or fixed bearing member and a rotary hub or a fixing frame which are formed of metals of different types, is interposed between the two members so as to prevent the occurrence or advance of potential difference corrosion. Relief portions are respectively provided at a joining interface between a rotary shaft and a thrust plate and a joining interface between a bearing member and the counter plate, and the respective members are welded in the relief portions so as to be integrated.

Abstract: A potential-difference alleviating member for alleviating and lowering the potential difference, which is an energy difference between a rotating or fixed bearing member and a rotary hub or a fixing frame which are formed of metals of different types, is interposed between the two members so as to prevent the occurrence or advance of potential difference corrosion. Relief portions are respectively provided at a joining interface between a rotary shaft and a thrust plate and a joining interface between a bearing member and the counter plate, and the respective members are welded in the relief portions so as to be integrated.

Abstract: A shaft member 21 the flexible, austenitic stainless steel is cold worked, and in the cold working process, a cold working ratio is increased, whereby a surface of the shaft member 21 is hardened. Therefore, there is no need for a nitriding treatment for the surface hardening. The corrosion proof performance of the passive coating possessed by the stainless steel is kept as intact.

Abstract: A hydrodynamic bearing apparatus comprises two hydrodynamic bearing sections which have a shaft member, a bearing member fit to the shaft member with a predetermined space therein, lubricants filling the space between the shaft member and the bearing member, and which are separately placed in the axial direction of the shaft member. The lubricants of the two hydrodynamic bearing sections are separated from each other by an air layer. The lubricants are pressured by hydrodynamic generating grooves formed on the hydrodynamic bearing sections such that the shaft member and the bearing member are rotatably supported in relation to each other. The hydrodynamic generating grooves separately formed on the two hydrodynamic bearing sections are formed into an unbalanced shape such that the lubricants are moved in a predetermined direction to correct the slope of the shaft member and the bearing member when rotation is suspended.

Abstract: A thrust dynamic pressure bearing apparatus includes a shaft member and a thrust plate having a fixing hole that is provided with chamfered sections Ca and Cb at the fixing hole. The shaft member is shrink fitted or pressure inserted in the fixing hole of the thrust plate. The chamfered sections Ca and Cb have axial lengths La and Lb in the axial direction. Dimensional relations of the axial lengths La and Lb in the chamfered sections Ca and Cb are set to be within a specified range to evenly distribute the bonding force of the thrust plate applied to the shaft member along the axial direction.

Abstract: A gas dynamic pressure bearing apparatus comprises a fixed shaft, a bearing member which is positioned opposite from the fixed shaft and at least a radial gas dynamic pressure bearing portion and a thrust gas dynamic pressure bearing portion which are positioned in a space between the fixed shaft and the bearing member. Dynamic pressure generating means are included for pressurizing gas in the radial gas dynamic pressure bearing portion and the thrust gas dynamic pressure bearing portion such that dynamic pressure action is generated. The bearing member is rotatably supported in relation to the fixed shaft by means of the pressurizing action such that rotational driving is performed by a predetermined motor. The radial gas dynamic pressure bearing portion and the thrust gas dynamic pressure bearing portion are structured such that gas is sealed from the space around the motor by a space sealing means and that gas flows from one side to other.