Minebea Company, Limited

Precision Motors Deutsche Minebea Gmbh

Thilo Rehm

J&ouml;rg Hoffmann

Olaf Winterhalter

Martin Bauer

Joerg Hoffmann

Andreas Kull

Martin Engesser

Stefan Schwamberger

Rudolf Neumann

Martin Hafen

Tobias Kirchmeier

Mathias Wildpreth

Jürgen Oelsch

Joerg Hoffman

Igor Ross

Claudia Hoffmann

Ralf Dittes

Helmut Hueneke

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

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 spindle motor having a deep-drawn baseplate and an aperture to receive and secure a bearing system to rotatably support a rotor. To avoid having to machine the bearing receiving portion of the baseplate in a complex process, the invention provides for a separate bush to be disposed in the aperture in the baseplate to receive and secure the bearing system. Compared to the baseplate, this bush can be worked in a simpler and more cost-saving process.

Spindle motor having a deep-drawn baseplate

The invention relates to a spindle motor having a hydrodynamic bearing system, particularly to drive platters in a hard disk drive, the platters being disposed on a rotor, and the bearing system being formed by a bearing sleeve arranged on a baseplate and a shaft rotatably supported in an opening in the bearing sleeve and at least one thrust plate connected to the shaft. A liquid lubricant is filled into a bearing gap formed between the shaft, the thrust plate and the bearing sleeve. The invention is characterized in that the thrust plate rests directly against the rotor and is accommodated in an annular recess in the bearing sleeve facing the rotor.

Spindle motor having a hydrodynamic bearing system

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.

Hydrodynamic thrust bearing

Permanent electro-conductive connection is achieved between a bearing component and a baseplate/flange by providing at least one solid-state contact element between the baseplate/flange and the bearing component. The contact element establishes an electric contact between these parts by exercising mechanical force on the baseplate/flange and/or the bearing component. Alternatively, at least one welding seam may be formed between the baseplate/flange and the bearing component to establish the electro-conductive connection.

Spindle motor with an electro-conductive connection between the bearing system and the baseplate or flange

The invention related to a spindle motor for hard disk drives with improved running accuracy where the sheet metal package or the complete stator consisting of sheet metal package and windings is encompassed by a centering casing of plastic, which is preferably applied by means of an injection molding operation. Depending on the design of the spindle motor the centering casing can be centered on the stationary shaft and/or on the outer rings/inner raceways pertaining to the sets of roolling bodies. Furthermore, a stator without centering casing is described whose sheet metal package is centered directly on the outer rings/inner raceways.

Spindle motor for hard disk drives with improved running accuracy

The invention relates to a spindle motor having a sealing support film which prevents exchange of air between the interior and surroundings of the spindle motor. In spindle motors for hard disk drives it is extremely important to construct the spindle motor so that it is sealed tight against the external environment, ie so that from the connecting side of the spindle motor no admission of air to the interior of the spindle motor can occur. A further characteristic of the invention consists in that the support film is bonded and fixed in place in sealing manner by means of an adhesive which does not give off gas or does so only very slightly.

Spindle motor with sealing, flexible support film

A spindle-drive motor for hard drives having a baseplate, a shaft and one or more bearings for rotational mounting of a rotationally driven rotor, with at least one magnetic fluid seal arranged between the stationary part and the rotating part of the spindle-drive motor. The seal is formed of an upper and a lower yoke lamination and a magnet disk arranged between the yoke laminations, where a concentric chamber is formed so that it is open toward the inside on one side to hold a magnetically conducting fluid. A flux concentrating lamination extends into this chamber. In one embodiment of this invention, the flux concentrating lamination is in direct or indirect contact with one end face of the inner bearing ring of the bearing, while the outer part of the magnetic fluid seal is in direct or indirect contact with the end face of the outer bearing ring of the bearing. In another embodiment, the flux concentrating lamination on the inside is in direct or indirect contact with a radial reference shoulder of the shaft.

Growing community of inventors

Villingen-Schwenningen, Germany

Thilo Rehm