Minebea Company, Limited

Martin Bauer

Stefan Schwamberger

Vladimir Vladimirovich Popov

Martin Engesser

Guido Schmid

Olaf Winterhalter

Thomas Fuss

Thilo Rehm

Jürgen Fleig

Frank Drautz

Matthias Wildpreth

Andreas Kull

Mathias Wildpreth

Igor Ross

Frank Brechtefeld

The invention relates to a spindle motor having a fluid dynamic bearing system comprising axial and radial bearings that contains a rotor component () which encloses a stationary shaft (), which in turn is connected at both its ends to axially aligned bearing parts () that are fashioned such that they form capillary sealing gaps (), a recirculation channel () filled with bearing fluid that connects the remote regions of the bearing to each other, and an electromagnetic drive system () for driving the rotor component.

Spindle motor having a fluid dynamic bearing system and a stationary shaft

The invention relates to a fluid dynamic bearing system having a bearing bush and a shaft that are rotatable with respect to one another about a common rotational axis and form a bearing gap filled with bearing fluid between associated bearing surfaces. The bearing surfaces form at least one fluid dynamic radial bearing. A rotor component is disposed on the shaft. A stopper ring is disposed on the shaft or on the rotor component and adjoins the bearing bush, wherein a gap is formed between the mutually facing surfaces of the bearing bush and the stopper component that is filled with a bearing fluid and connected to the bearing gap and extends substantially in a radial direction. According to the invention, the surfaces of the bearing bush and/or the stopper component are formed such that the gap is tapered, narrowing radially outwards. Moreover, a recirculation channel may be provided in the bearing bush that connects a gap region between the bearing gap and the sealing gap radially outside the axial bearing to a gap region radially outside the stopper component.

Fluid dynamic bearing system and a spindle motor having this kind of bearing system

A fluid dynamic bearing system having pressure-generating surface patterns that comprises at least two bearing parts that are rotatable with respect to one another and form a bearing gap filled with bearing fluid between associated bearing surfaces. The surface patterns are disposed on at least one bearing surface that is defined by a first rim and a second rim, hydrodynamic pressure being built up within the bearing gap on rotation of the bearing parts with respect to one another. At least parts of the surface patterns extend from the first rim to the second rim of the bearing surface.

Fluid dynamic bearing having pressure-generating surface patterns

The invention relates to a fluid dynamic bearing system having pressure-generating surface patterns that comprises at least two bearing parts that are rotatable with respect to one another and form a bearing gap filled with bearing fluid between associated bearing surfaces. The surface patterns are disposed on at least one bearing surface that is defined by a first rim and a second rim, hydrodynamic pressure being built up within the bearing gap on rotation of the bearing parts with respect to one another. According to the invention, at least parts of the surface patterns extend from the first rim to the second rim of the bearing surface.

The invention relates to a magnetic axial bearing for taking up axial forces that act on a rotor component that is rotatably supported about a rotational axis with respect to a stator component. The bearing comprises a first bearing part consisting of at least one permanent magnet and at least two flux guide elements associated with the permanent magnet that are disposed on opposing end faces of the permanent magnet and aligned substantially radial and perpendicular to the rotational axis, and a second bearing part consisting of at least two flux guide elements that are disposed at a mutual spacing to one another and aligned substantially radial and perpendicular to the rotational axis, each flux guide element of the second bearing part being associated with a flux guide element of the first bearing part and lying directly opposite the latter in a radial direction and separated from it by an air gap. The invention further describes a spindle motor having a magnetic axial bearing of this kind, used, for example, for driving a hard disk drive.

Magnetic axial bearing and a spindle motor having this kind of magnetic axial bearing

The invention relates to a fluid dynamic bearing system that comprises at least one stationary part that has a shaft and two bearing plates disposed on the shaft at a mutual spacing, and at least one rotating part that is supported so as to rotate about a rotational axis with respect to the stationary part, and comprises a bearing bush and a sleeve enclosing the bearing bush. A bearing gap filled with bearing fluid is provided between the parts and at least one sealing gap for sealing the bearing gap that extends concentric to the rotational axis. The bearing comprises at least one fluid dynamic radial bearing and two fluid dynamic axial bearings and at least one recirculation channel that connects the two axial bearing regions to each other. According to the invention, the largest radial diameter of the recirculation channel is greater than or equal to the largest diameter of the sealing gap, and the smallest radial diameter of the recirculation channel is greater than or equal to the largest diameter of an adjacent bearing plate. Moreover, additional and effective deairing of the recirculation channel is effected by a venting device. To realize improved equilibrium of pressure in the bearing gap and improved retention of the bearing fluid, the sealing gaps can be inclined, at least in sections, at an angle &#x3b1;, &#x3b2; with respect to the rotational axis, wherein the angles may have different sizes.

Fluid dynamic bearing system

The invention relates to a fluid dynamic bearing system having a first conical bearing and a second conical bearing working in opposition to the first conical bearing, the conical bearings being disposed along a stationary shaft. The first conical bearing has a first bearing cone disposed on the shaft having bearing surfaces extending at an angle &#x3b1; to the rotational axis, and a first bearing bush having a tapered bearing bore and bearing surfaces that are separated by a first bearing gap filled with bearing fluid from the bearing surfaces of the first bearing cone. The second conical bearing has a second bearing cone disposed on the shaft having bearing surfaces extending at an angle &#x3b2; to the rotational axis, and a second bearing bush having a tapered bearing bore and bearing surfaces that are separated by a second bearing gap filled with bearing fluid from the bearing surfaces of the second bearing cone. According to the invention, the bearing surfaces of the first conical bearing are smaller in surface area than the bearing surfaces of the second conical bearing and the angle &#x3b1; is greater than the angle &#x3b2;.

The invention relates to a spindle motor having a fluid dynamic bearing system that contains a rotor component taking the form of an integrated hub/bearing bush arrangement which encloses a straight, stationary shaft, which in turn is connected at both its ends to axially aligned bearing components, formed in such a way that they seal the fluid dynamic bearing system formed between the shaft and the rotor component and open at both ends. The open ends of the bearing gap are sealed by capillary seals or pumping seals or a combination of capillary and pumping seal.

A permanent magnetic motor having a magnetic axial bearing and one or more fluid bearings, wherein a stator unit is disposed on a baseplate, the stator unit being disposed opposite a magnet ring made up of permanent magnets and being separated from the magnet ring by an air gap, and the magnet ring is fixed to the inside circumference of a circumferential hub that is supported with respect to a bearing bush by means of the fluid bearings via a shaft, and at least one fluid dynamic axial bearing is preloaded with an axial attractive force component that is at least partly generated by a ferromagnetic pull ring that is fixed to the baseplate and disposed below the magnet ring and permeated by its field lines, characterized in that, seen magnetically, the stator unit is centered with respect to the magnet ring and has no significant axial offset and that the pull ring has no or only relatively low electrical conductivity at high magnetic permeability.

Permanent magnetic motor having a magnetic axial bearing

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.

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Villingen-Schwenningen, Germany

Martin Bauer