Seagate Technology Incorporated

Samnathan Murthy

Hans L Leuthold

Norbert Steven Parsoneault

Alan Lyndon Grantz

Mohamed Mizanur Rahman

Roger Allen Addy

David John Jennings

Matt L Shumway

Raquib Uddin Khan

Wesley R Clark

Etoli Wolff

Michael David Kennedy

Peter R Riegler

Steve Parsoneault

A hydrodynamic bearing system where the bearing includes a shaft and two independent bearings, including a top cone or bi-sphere and a bottom cone or bi-sphere separated by a segment of the shaft. The bearing includes a hub supported bearing element rotating around the shaft and the shaft supported top cone and bottom cone; complementary surfaces of the bearing element and the cone define a narrow gap between the bearing support element for the bearing fluid. Sealing plates or seal elements define a fluid gap with a radially extending face of the cone; a gap also exists between an interior surface portion of each cone and the shaft. These gaps are connected so that separate flow paths are established, one around the top cone or bi-sphere and one around the bottom cone or bi-sphere. By providing two independent bearings, the stator can be mounted to the shaft, facing magnets supported on the hub to form an in-hub motor. When the load or RPM changes, the fluid pressure or movement in each bearing may change but the function of the bearing and its ability to provide stiffness and stability to the system will not be lessened.

In-hub spindle motor with separate fluid dynamic bearings

A hydrodynamic bearing having a shaft relatively rotatable with rest to a surrounding sleeve and having a thrust plate of or near one end thereof. The shaft and sleeve define a journal bearing extending substantially the full length of the two relatively rotating parts.

Single plate hydrodynamic bearing with extended single journal bearing

A bearing assembly including a bearing cone (,) having a crowned bearing surface (,) with V-shaped grooves (,) that are shallow at their apex (,) and deepest at the outer edges (,). When mated with a female bearing seat, lubricating fluid builds up along the midline of the bearing surface as the bearing seat rotates about the bearing cone.

Crowned conical bearing

A hydrodynamic bearing useful as a bearing cartridge or as the cartridge may be incorporated into a spindle motor or the like, where the bearing includes a stationary shaft and two independent bearings, comprising a top cone and a bottom cone separated by a segment of the shaft. The bearing includes a sleeve rotating around and surrounding the shaft, and the top cone and bottom cone and defining a narrow gap between the sleeve and the shaft and cones. Sealing plates are supported on the sleeve to seal off the ends of the bearing and are located along the shaft beyond the cones. A gap also exists between an interior surface portion of each cone and the shaft. Thus, separate flow paths are established, one around the top cone and one around the bottom cone. By providing two independent paths, the flow rates do not have to be the same in each conical flow path for the bearing seals to function properly.

Simplified conical bearing with independent flow paths

A hydrodynamic bearing system where the bearing includes a shaft and two independent bearings, comprising a top cone or bi-sphere and a bottom cone or bi-sphere separated by a segment of the shaft. The bearing includes a hub supported bearing element rotating around the shaft and the shaft supported top cone and bottom cone; complementary surfaces of said bearing element and said cone define a narrow gap between the bearing support element for the bearing fluid. Sealing plates or seal elements define a fluid gap with a radially extending face of the cone; a gap also exists between an interior surface portion of each cone and the shaft. These gaps are connected so that separate flow paths are established, one around the top cone or bi-sphere and one around the bottom cone or bi-sphere. By providing two independent bearings, the stator can be mounted to the shaft, facing magnets supported on the hub to form an in-hub motor. When the load or RPM changes, the fluid pressure or movement in each bearing may change but the function of the bearing and its ability to provide stiffness and stability to the system will not be lessened.

A bimetallic part is formed from metals or comprises metals with different thermal expansion coefficients. A first element defines the part and defines one surface of the bearing gap and has a first coefficient of expansion and a second element is wholly or partially inserted into and constrained within the first element and having a different coefficient of thermal expansion so that as the temperature changes, the stress created by the differential expansion of the two elements will cause the overall part to deform elastically as a function of temperature. This deformation will cause the gap, the elements being properly selected, to narrow as temperature rises (and viscosity falls) and to widen as temperature falls (and viscosity rises).

Thermal compensation for fluid dynamic bearing using bimetal parts

A bearing assembly including a bering cone (50) having a crowned bearing surface (56) with V-shaped grooves (60) that are shallow at their apex (62) and deepest at the outer edges (52, 54). When mated with a female bearing seat, lubricating fluid builds up along the midline of the bearing surface as the bearing seat rotates about the bearing cone.

An apparatus for forming grooves in the surface of an article is disclosed. The apparatus includes a cage which has a circular cage wall with an annular pattern of holes in the wall. The apparatus also includes a plurality of spherical balls, each rotatably disposed in a respective hole of the cage wall and has a diameter greater than the wall thickness. The apparatus further includes a pin located within the cage, the pin has a circumferential groove in a plane coincident with the plurality of spherical balls and holes in the cage wall so that the pin holds the balls in the groove, the balls protruding through the cage wall and engaging the surface of a workpiece to be grooved so that the balls roll in the groove in the pin and, with movement of the workpiece and the apparatus, cause grooves to be formed in the interior surface of the workpiece. Lastly, the apparatus further includes an object at either end of the pin for holding the pin against translational movement relative to the cage with movement of the apparatus and the workpiece so that only a rotational movement is imparted to the pin by rotation of the workpiece.

Device for manufacturing a groove bearing

Disc drive hydro bearing lubricant with electrically conductive,

For a precision spindle motor, an invention for reducing distortion resulting from interference fits of a thrust plate to spindle motor shaft and of a counter plate to a journal. A method of assembly according to the invention includes the step of balancing an interference pressure about a centerline of at least one of the thrust plate and the counter plate of the spindle motor. A precision spindle motor according to the invention comprises a journal having a bore defined therein, a shaft located in the bore, a thrust plate mounted to a top portion of the shaft by means of an interference fit, and a counter plate mounted to the journal adjacent to the thrust plate by means of an interference fit, wherein an interference pressure is balanced about a centerline of at least one of the thrust plate and the counter plate.

Low distortion interference fits for spindle motor assembly

For a precision spindle motor, an invention for facilitating interference fits of a thrust plate to spindle motor shaft and of a counter plate to journal. A method is provided for assembling a spindle motor using press fits of a thrust plate to a shaft having an undercut for providing a relief to reduce unwanted translation into a thrust gap. A method is also provided for assembling a spindle motor using a press fit of a counter plate to a journal. The counter plate having a chamfer for reducing unwanted translation of the counter plate into a thrust gap. Also, the apparatus employed for the above methods are described.

Growing community of inventors

Santa Cruz, CA, United States of America

Samnathan Murthy