Minebea Company, Limited

Minebea Mitsumi Inc.

Andreas Kull

Olaf Winterhalter

Joerg Hoffmann

Martin Hafen

Tobias Kirchmeier

Jorg Hoffmann

Martin Bauer

Rudolf Neumann

Thilo Rehm

Tadashi Akahori

Dieter Braun

Frank Drautz

Mathias Wildpreth

Joerg Hoffman

Michael Bruckhoff

Toshimitsu Horiuchi

The invention relates to a fluid-dynamic bearing system, in particular for the rotary support of a spindle motor, the bearing system comprising: a first conical bearing and a second conical bearing counteracting the first conical bearing, a fixed shaft along which the two conical bearings are arranged, a sleeve, a first and a second conical bearing component, which together with the sleeve form the first and second conical bearings, bearing structures applied to the sleeve and/or the conical bearing components, a bearing gap filled with a bearing fluid extending between the sleeve and the shaft and between the sleeve and the conical bearing components and sealed at each of its ends by a conical capillary seal, and a hub which rotates together with the sleeve about a rotation axis. The invention is characterized in that a pump seal is arranged between the first conical bearing and the adjacent capillary seal.

Fluid-dynamic bearing system

A fluid dynamic bearing including a bearing bush having a central bearing bore in which a shaft is rotatably supported. Surfaces of the shaft and of the bearing bore that face each other are separated from one another by a bearing gap filled with a bearing fluid. A first radial bearing section and a second radial bearing section are disposed along the bearing gap, between which a separator section is disposed. The width of the bearing gap varies with its axial length. The bearing gap has a first inner width iband a second inner width ibin the region of the first and of the second radial bearing section on the sides facing the separator section, a first outer width aband a second outer width abon the sides remote from the separator section. According to the invention, the differences resulting from the inner widths and the outer widths, ib&#x2212;aband ib&#x2212;ab, lie in an interval of a&#x2212;t to a+t, where a is greater than zero and t is greater than a.

Fluid dynamic bearing system and a spindle motor having a fluid dynamic bearing system

A fluid dynamic bearing having at least one first bearing part as well as a second bearing part that are rotatably supported with respect to one another about a rotational axis and separated from one another by a bearing gap filled with bearing fluid. Associated bearing surfaces of the bearing parts form a first and a second radial bearing that are marked by grooved bearing patterns disposed on at least one bearing surface. Between the radial bearings, there is a separator gap having an enlarged gap distance compared to the bearing gap. The ends of the grooved bearing patterns of the radial bearings adjoining the separator gap penetrate into the separator gap. This measure prevents the creation of negative pressure at the ends of the grooved bearing patterns, as a result of which the formation of air bubbles is also reduced.

Fluid dynamic 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.

Spindle motor

The invention relates to a fluid dynamic bearing system particularly to rotatably support a spindle motor to drive the disk(s) of a hard disk drive. The bearing system comprises a bearing sleeve and a shaft accommodated in a bore in the bearing sleeve and rotatably supported with respect to the bearing sleeve, the surfaces of the bearing sleeve and of the shaft, which face each other and are separated by a bearing gap () filled with a bearing fluid, forming at least one first radial bearing region. According to the invention the diameter of the shaft is chosen such that the relationship between the bearing distance, i.e. the distance of the fixing point of the shaft to the first radial bearing region, and the diameter of the shaft is equal to or less than 0.9, and that the diameter of the shaft is preferably 3 mm to 5 mm. This provision causes the resonance frequency of the bearing to shift to a higher, uncritical frequency range.

Fluid dynamic bearing system

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

The invention relates to a hydrodynamic bearing, particularly for a spindle motor, comprising a shaft, a thrust plate connected to the shaft and a bearing sleeve closed at one end by a cover plate, the bearing sleeve enclosing the shaft and the thrust plate with a slight radial spacing forming a concentric bearing gap filled with a lubricant. As is already known, the surfaces of the bearing sleeve and the shaft facing each other form at least one radial bearing region and the surfaces of the bearing sleeve, the cover plate and the thrust plate facing each other form at least one axial bearing region. In the hydrodynamic bearing according to the invention, at least one connecting channel is provided which connects a section between the bearing sleeve and the shaft abutting the radial bearing region and a section of the bearing gap abutting the axial bearing region to each other.

Hydrodynamic bearing, spindle motor and hard disk drive

A hydrodynamic bearing system, particularly for the rotary bearing of spindle motors to power hard disk drives. The bearing system includes a bearing sleeve, a shaft accommodated in an opening in the bearing sleeve and at least one radial bearing section provided between the bearing sleeve and the shaft with the aid of which the shaft and the bearing sleeve are supported rotatably in relation to each other. A bearing gap is formed between the shaft and the bearing sleeve and is filled with a liquid lubricant. A lubricant reservoir and equalizing volume independent from the design of the bearing arrangement is provided in that at least one duct is formed in the bearing sleeve that extends from an outer section of the bearing sleeve to the bearing gap and that is at least partially filled with lubricant.

Hydrodynamic bearing system for a rotary bearing of spindle motors

The present invention provides a bearing comprised of a hydrodynamic bearing and a pivot bearing, which can be used with a spindle motor. It also provides a spindle motor utilizing a hydrodynamic bearing and a pivot bearing.

Hydrodynamic pivot bearing

A spindle motor for use in hard disk drives having a base plate, a stationary shaft, a rotationally driven rotor, and a bearing system rotationally supporting the rotationally driven rotor. The shaft is fixedly mounted on the base plate. The base plate includes a drilled hole for insertion of a portion of the shaft such that this shaft's portion and the inner surface of the hole define a joint length l, when this portion is pressed into the drilled hole. The shaft has at least one notch located along the shaft's circumference and interrupting the joint length l.

Spindle motor for hard disk drives

A spindle motor for use in a disk drive including a shaft and a bearing sleeve. The shaft has a larger diameter section and a smaller diameter section with a step formed therebetween. The bearing sleeve has a central cylindrical opening, the shaft being inserted into the central cylindrical opening. A bearing gap is formed between the shaft and the bearing sleeve, the bearing gap being filled with lubricating fluid. A first hydrodynamic thrust bearing is formed in the area of the step. A hydrodynamic radial bearing is formed in the area of the larger diameter section of said shaft.

Low power spindle motor with a fluid dynamic spool bearing

An apparatus for and a method of construction of a spindle motor having a bearing unit, a rotary shaft, a rotary hub member and an electro-magnetic motor is presented. The rotary shaft has a flange attached at a mid-section in an axial direction, between large and small diameter sections of the rotary shaft. Grooves between the bearing unit, rotary shaft and flange create radial dynamic pressure generating areas, each with as long as possible a span, and thrust dynamic pressure generating areas to both sides of the flange.

Dynamo-electric machine having a rotor with first and second axially or rotationally displacable field magnets

A spindle motor for use in a disk drive having a rotor assembly and a stator assembly. The rotor assembly has a hub and a rotating shaft with an outer diameter, the hub being mounted for rotation on the rotating shaft. The stator assembly has a bearing sleeve with a bottom opening, the rotating shaft being inserted into the bearing sleeve for rotation. A counter-plate is inserted into the bottom opening of the bearing sleeve thereby closing the bottom opening. A thrust plate is mounted on the rotating shaft in opposing relationship with the counter-plate, the thrust plate having an outer diameter. A fluid dynamic thrust bearing is formed between the counter-plate and the thrust plate. A ratio between the outer diameter of the shaft to the outer diameter of the thrust plate is reduced to reduce spindle motor's power consumption.

Low power spindle motor with a fluid dynamic thrust bearing having a reduced outer diameter

A spindle motor for use in a disk drive, the spindle motor including a shaft having a larger diameter section and a smaller diameter section with a step formed therebetween. The spindle motor also includes a bearing sleeve having a central cylindrical opening, the shaft is inserted into the central cylindrical opening. A bearing gap is formed between the shaft and the bearing sleeve, the bearing gap being filled with lubricating fluid. A thrust plate is fixedly mounted on the shaft in the area of the step such that an upper side of the thrust plate is placed adjacently to the larger diameter section and a lower side of the thrust plate is placed adjacently to the smaller diameter section of the shaft.

Growing community of inventors

Donaueschingen, Germany

Andreas Kull