Abstract: The invention relates to a method for manufacturing a tool electrode for the electrochemical machining of workpieces, particularly for components for fluid bearings with the following processing steps: (a) Providing an electrode body made of a conductive base material which has an essentially smooth surface; (b) Coating the surface of the electrode body with an insulating material; (c) Removing the insulating material from locations on the surface of the electrode body that correspond to a pattern which is to be formed on the surface of the piece by means of electromechanical machining.

Abstract: The invention relates to a hydrodynamic bearing system particularly for the rotary bearing of spindle motors to drive the platters in hard disk drives which comprises at least one inner bearing part and at least one outer bearing part, the bearing parts being rotatable about a rotational axis with respect to one another. The bearing system has at least one radial bearing region and/or at least one axial bearing region which are formed on surfaces of the bearing parts facing each other. A bearing gap filled with lubricant is formed between the surfaces of the bearing parts facing each other and is connected to an equalizing volume in a fluid-conducting way. According to the invention, the equalizing volume is formed from a single or multiple thread provided on the circumference of the outer bearing part. The outer bearing part is enclosed by a sleeve so that a winding channel acting as an equalizing volume is formed between the outer bearing part and the sleeve.

Abstract: If the motor housing 5 is manufactured with a resin, the housing 5 becomes possible to be manufactured by injection molding, so that the housing 5 can be intended to lower the manufacturing cost by a mass production. Further, the counter measures for insulation such as covering a copper wire 7 with an insulating tape, interposing an insulator to an opening 5a of the housing installing an insulating shim between the coil 6a and the housing 5 become unnecessary. As a result, it becomes possible to expect a cost down of the spindle motor due to the reduction of the cost of the parts for insulating members and the mounting processes. And, further, since a vibration transmitted from the rotor 1 through the bearing and a vibration caused by an electric switching of the stator 6 etc. are diminished due to elastic absorbing function of the housing 5, rotation noise of the spindle motor can be reduced.

Abstract: The invention relates to an electronically commutated electric motor having a multi-pole magnetized permanent magnet, a plurality of flux guide units each of which features at least one flux collector section and one flux concentrator section, whereby each flux guide unit picks up a radial magnetic flux from the permanent magnet and redirects it into a transversal magnetic flux, and having a plurality of coils each of which is allocated to a flux guide unit and is arranged axially parallel to the permanent magnet.

Abstract: A hydrodynamic bearing having a shaft (10) and a bearing sleeve (12), which encloses the shaft with a slight radial clearance forming a concentric bearing gap. An equalizing volume cavity (20) is formed at at least one end of the bearing. At least one micro-passage (26) connects the bearing gap via appropriate openings with the equalizing volume cavity (20). Bearing fluid completely fills the bearing gap (24) and the micro-passage (26) and at least partially fills the equalizing volume cavity (20). The bearing fluid forms a continuous fluid film between the bearing gap (24) and the equalizing volume cavity (20).

Abstract: A hydrodynamic thrust bearing, particularly forming a part of a bearing system for a rotary bearing of spindle motors utilized to power hard disk drives. The thrust bearing includes at least one annular thrust plate and a counter bearing corresponding to the thrust plate. The thrust plate is fixedly mounted on a shaft rotatably supported by means of a radial bearing system. The thrust plate is arranged on the shaft which is provided with an axial bore in the area where the thrust plate is to be positioned. A spherical element fixing the thrust plate is pressed into the axial bore. An outer diameter of the fixing element is greater than the inner diameter of the axial bore. This type of press connection between the thrust plate and the shaft allows comparatively thinner thrust plates to be used while the performance of the thrust bearing remains the same or improves.

Abstract: A hydrodynamic bearing having a shaft, which is fixedly connected at one end to a rotating component, and a bearing sleeve, which encompasses the shaft at its other free end with a slight clearance. The sleeve and the shaft form a concentric bearing gap. The shaft and/or the bearing sleeve is provided with at least one groove pattern which forms at least one radial hydrodynamic bearing. A volume equalizing cavity and at least one connecting passage connecting the bearing gap with the volume equalizing cavity extend radially outwards at an angle to the bearing gap.

Abstract: A hydrodynamic thrust bearing, forming a part of a bearing system for a rotary bearing of spindle motors utilized to power hard disk drives, which includes at least one annular thrust plate and a counter bearing corresponding to the thrust plate. The thrust plate is firmly connected to a shaft rotatably supported by a radial bearing system. The shaft features an axial bore extends from one shaft end located outside the bearing system until the area where the thrust plate is to be positioned. A fixing element is inserted into the axial bore, an outer diameter of the fixing element being greater than the smallest inner diameter of the bore. This enables the thrust plate to be easily mounted in a press fit even in the area around the middle of the shaft.

Abstract: The invention relates to a hydrodynamic bearing system particularly for the rotary bearing of spindle motors to drive the platters in hard disk drives which comprises at least one inner bearing part and at least one outer bearing part, the bearing parts being rotatable about a rotational axis with respect to one another. The bearing system has at least one radial bearing region and/or at least one axial bearing region which are formed on surfaces of the bearing parts facing each other. A bearing gap filled with lubricant is formed between the surfaces of the bearing parts facing each other and is connected to an equalizing volume in a fluid-conducting way. According to the invention, the equalizing volume is formed from a single or multiple thread provided on the circumference of the outer bearing part. The outer bearing part is enclosed by a sleeve so that a winding channel acting as an equalizing volume is formed between the outer bearing part and the sleeve.

Abstract: The invention relates to a hydrodynamic bearing system particularly for use as a rotary bearing in a spindle motor for a hard disk drive, comprising a shaft, a thrust plate firmly connected to the shaft by means of a pressfit connection and a bearing sleeve closed at least at one end by a cover plate, the bearing sleeve enclosing the shaft and the thrust plate with a slight radial or axial spacing forming a concentric bearing gap filled with a lubricant. In the hydrodynamic bearing system according to the invention, it is provided that the outer circumference of the shaft, in the area of connection with the thrust plate, has a surface interrupted by regular depressions, preferably formed by knurling, in order to decrease the contact surface proportion of the fit surface. As an alternative, the inner circumference of the thrust plate can also be knurled in the area of connection with the shaft.

Abstract: A hydrodynamic thrust bearing, particularly forming a part of a bearing system for a rotary bearing of spindle motors utilized to power hard disk drives. The thrust bearing includes at least one annular thrust plate and a counter bearing corresponding to the thrust plate, wherein the thrust plate is firmly connected to a shaft rotatably supported by means of a radial bearing system. The thrust plate is arranged on the shaft which has an axial bore in the area where the thrust plate is to be positioned. A fixing element affixing the thrust plate to the shaft is pressed into the axial bore of the shaft. The outer diameter of the fixing element is greater than the inner diameter of the axial bore. This type of press connection between the thrust plate and the shaft allows thinner thrust plates to be utilized with the performance of the thrust bearing remaining the same or improving.

Abstract: A hydrodynamic thrust bearing, forming a part of a bearing system for a rotary bearing of spindle motors utilized to power hard disk drives, which includes at least one annular thrust plate and a counter bearing corresponding to the thrust plate. The thrust plate is firmly connected to a shaft rotatably supported by means of a radial bearing system. The shaft features an axial bore extends from one shaft end located outside the bearing system until the area where the thrust plate is to be positioned. A fixing element is inserted into the axial bore, an outer diameter of the fixing element being greater than the smallest inner diameter of the bore. This enables the thrust plate to be easily mounted in a press fit even in the area around the middle of the shaft.

Abstract: If the motor housing 5 is manufactured with a resin, the housing 5 becomes possible to be manufactured by injection molding, so that the housing 5 can be intended to lower the manufacturing cost by a mass production. Further, the counter measures for insulation such as covering a copper wire 7 with an insulating tape, interposing an insulator to an opening 5a of the housing installing an insulating shim between the coil 6a and the housing 5 become unnecessary. As a result, it becomes possible to expect a cost down of the spindle motor due to the reduction of the cost of the parts for insulating members and the mounting processes. And, further, since a vibration transmitted from the rotor 1 through the bearing and a vibration caused by an electric switching of the stator 6 etc. are diminished due to elastic absorbing function of the housing 5, rotation noise of the spindle motor can be reduced.

Abstract: A hydrodynamic thrust bearing, particularly forming a part of a bearing system for a rotary bearing of spindle motors utilized to power hard disk drives. The thrust bearing includes at least one annular thrust plate and a counter bearing corresponding to the thrust plate, wherein the thrust plate is firmly connected to a shaft rotatably supported by means of a radial bearing system. The thrust plate is arranged on the shaft which has an axial bore in the area where the thrust plate is to be positioned. A fixing element affixing the thrust plate to the shaft is pressed into the axial bore of the shaft. The outer diameter of the fixing element is greater than the inner diameter of the axial bore. This type of press connection between the thrust plate and the shaft allows thinner thrust plates to be utilized with the performance of the thrust bearing remaining the same or improving.

Abstract: If the motor housing 5 is manufactured with a resin, the housing 5 becomes possible to be manufactured by injection molding, so that the housing 5 can be intended to lower the manufacturing cost by a mass production. Further, the counter measures for insulation such as covering a copper wire 7 with an insulating tape, interposing an insulator to an opening 5a of the housing installing an insulating shim between the coil 6a and the housing 5 become unnecessary. As a result, it becomes possible to expect a cost down of the spindle motor due to the reduction of the cost of the parts for insulating members and the mounting processes. And, further, since a vibration transmitted from the rotor 1 through the bearing and a vibration caused by an electric switching of the stator 6 etc. are diminished due to elastic absorbing function of the housing 5, rotation noise of the spindle motor can be reduced.

Abstract: If the motor housing 5 is manufactured with a resin, the housing 5 becomes possible to be manufactured by injection molding, so that the housing 5 can be intended to lower the manufacturing cost by a mass production. Further, the counter measures for insulation such as covering a copper wire 7 with an insulating tape, interposing an insulator to an opening 5a of the housing installing an insulating shim between the coil 6a and the housing 5 become unnecessary. As a result, it becomes possible to expect a cost down of the spindle motor due to the reduction of the cost of the parts for insulating members and the mounting processes. And, further, since a vibration transmitted from the rotor 1 through the bearing and a vibration caused by an electric switching of the stator 6 etc. are diminished due to elastic absorbing function of the housing 5, rotation noise of the spindle motor can be reduced.

Abstract: A hydrodynamic bearing having a shaft, which is fixedly connected at one end to a rotating component, and a bearing sleeve, which encompasses the shaft at its other free end with a slight clearance. The sleeve and the shaft form a concentric bearing gap. The shaft and/or the bearing sleeve is provided with at least one groove pattern which forms at least one radial hydrodynamic bearing. A volume equalizing cavity and at least one connecting passage connecting the bearing gap with the volume equalizing cavity extend radially outwards at an angle to the bearing gap.

Abstract: A hydrodynamic bearing having a shaft (10) and a bearing sleeve (12), which encloses the shaft with a slight radial clearance forming a concentric bearing gap. An equalizing volume cavity (20) is formed at at least one end of the bearing. At least one micro-passage (26) connects the bearing gap via appropriate openings with the equalizing volume cavity (20). Bearing fluid completely fills the bearing gap (24) and the micro-passage (26) and at least partially fills the equalizing volume cavity (20). The bearing fluid forms a continuous fluid film between the bearing gap (24) and the equalizing volume cavity (20).

Abstract: The invention relates to a spindle motor, in particular for driving a hard disk drive, with a stator, a rotor and a shaft disposed between stator and rotor, which supports at least one roller bearing, which comprises an inner and an outer bearing ring with roller bodies disposed between them. According to the invention the spindle motor comprises a device for the temperature compensation. In a first embodiment the invention is distinguished thereby that at least one equilibration element is provided which acts onto the outer and/or inner bearing ring, [which element is] disposed between the corresponding bearing ring and a part supporting the bearing ring, and has a specified coefficient of thermal expansion &agr;. In a second embodiment the shaft is used as equilibration element, wherein the shaft comprises a material with a low coefficient of thermal expansion &agr;.

Abstract: The invention relates to a spindle motor for solid-plate running gears with a stator, a rotor, the shaft of which is turnably borne with the aid of rolling bearings with respect to the stator, and a shell, in which the shell is constructed as a separate pot-shaped part closed on one side, on the outer circumference of which the stator is held and on the inner circumference of which the outer rings of the rolling bearings are held.