| Patent application number | Description | Published |
|---|
| 20080229582 | SINGLE PIECE HUB WITH INTEGRAL UPPER AND LOWER FEMALE CONES AND METHOD FOR MAKING THE SAME - To simplify fabrication of an integral hub piece, the opening between the upper and lower female cones in this hub has sufficient width or radial dimension to allow access to both cones from one side of the hub with the cutting tool. A cutting tool is used which has a width smaller than the opening between the cones. Preferably, the tool has a width which is about equal to or smaller than an angular dimension through this opening which is defined by extending surfaces of the upper and lower female cones. If this limitation is satisfied, both cones can be created with a single machine set up operating from one side of the integrated hub. | 09-25-2008 |
| 20080317392 | Air purging for a fluid dynamic bearing - A robust spindle motor is provided having improved shock resistance for fluid containment, as well as enhanced air purging characteristics. In an aspect, axial displacement of relatively rotating components is restricted by utilizing a limiter situated adjacent to a limiter bushing forming an axial limiter gap therebetween. A fluid channel, at least partially diverging, extends from a hydrodynamic bearing to the axial limiter gap, and continues to a region beyond the axial limiter gap. In an aspect, an axially diverging slot is situated adjacent to the axial limiter gap. Power is reduced by reducing viscous drag between relatively rotating components, hydrodynamic bearing length is increased, and higher stiffness of the hydrodynamic bearing is provided. Fluid volume may be increased, thereby offsetting fluid evaporation losses and allowing for the use of lower viscosity lubricants. | 12-25-2008 |
| 20090103839 | Fluid dynamic bearing motor having molded plastic - A fluid dynamic bearing motor and method are described, wherein motor components, including complex shaped motor components, are molded of plastic. The molding ensures form control and dimensional control thereby accomplishing design requirements, and eliminating or reducing component costs and component machining. The mold can be shaped to form various motor geometries, thereby eliminating the need for multiple component assembly and related assembly costs. In an aspect, a plastic integral motor hub is formed by injection molding. Alternatively, a plastic motor hub is affixed to a metal sleeve. In another aspect, fluid containment structures are molded into the motor component, reducing the number of components as compared with machined metal components. In a further aspect, bearing structures such as grooves are molded into the motor component, thereby eliminating processes such as electrochemical machining. In yet a further aspect, a plastic hub faces a thrustplate, reducing expensive sleeve machining. | 04-23-2009 |
| 20090279818 | FOLDED FLUID CHANNEL FOR A FLUID DYNAMIC BEARING MOTOR - A system and method are provided for sealing a fluid dynamic bearing motor. A first and a second folded fluid channel are shaped for maximizing bearing axial span and establishing angular stiffness, to resist gyroscopic rocking of the facing bearing surfaces. The first folded fluid channel is limited to occupying at least a portion of the same axial space as the bearing. A first and a second fluid sealing system are connected to opposite axial ends of the bearing. The first fluid sealing system forms an active pumping seal to pump fluid during motor rotation. In an aspect, a top cover attached shaft, and a single thrust surface are employed, allowing for a rigid motor structure and power reduction in applications including high rotational speed disc drives. Also, by employing a rigid shaft design, significantly lower amplitude radial vibration responses are exhibited at higher frequencies than prior art motor designs. | 11-12-2009 |
| 20100142869 | Fluid Pumping Capillary Seal For A Fluid Dynamic Bearing - An apparatus and method are provided for a robust and shock resistant fluid dynamic bearing. A fluid sealing system with fluid pumping and capillary features provides increased reliability and performance for small form factor disc drive memory systems. Concerns of motor jog are addressed, jog being the rapid and repeated opening and closing of spaces between relatively rotatable components that can dispel oil from, or draw air into, these spaces. The fluid pumping capillary sealing system includes a fluid pumping groove with a rib portion and a slot portion for pumping fluid. The fluid pumping capillary sealing system also includes a capillary seal. In an aspect, a sweeping rib sweeps fluid toward the bearing. A truncated rib is situated adjacent to the sweeping rib, the truncated rib extending a shorter radial distance as compared to the sweeping rib and forming a plenum region. | 06-10-2010 |
| 20100247009 | AIR PURGING FOR A FLUID DYNAMIC BEARING - A robust spindle motor is provided having improved shock resistance for fluid containment, as well as enhanced air purging characteristics. In an aspect, axial displacement of relatively rotating components is restricted by utilizing a limiter situated adjacent to a limiter bushing forming an axial limiter gap therebetween. A fluid channel, at least partially diverging, extends from a hydrodynamic bearing to the axial limiter gap, and continues to a region beyond the axial limiter gap. In an aspect, an axially diverging slot is situated adjacent to the axial limiter gap. Power is reduced by reducing viscous drag between relatively rotating components, hydrodynamic bearing length is increased, and higher stiffness of the hydrodynamic bearing is provided. Fluid volume may be increased, thereby offsetting fluid evaporation losses and allowing for the use of lower viscosity lubricants. | 09-30-2010 |
| 20100303393 | Microfabricated Fluid Dynamic Bearing - A fluid dynamic bearing formed by a microelectromechanical systems (MEMS) wafer-level batch-fabrication process is provided. The process results in a high performance and high reliability fluid dynamic bearing having features including higher bearing lifetime at high RPM, improved bearing stiffness, durability and thrust/restoring forces capabilities. The present invention is especially useful with small form factor disc drive memory devices having constraints in motor height, such as a 2.5 inch disc drive, requiring high performance including high rotational speed and large areal density. A sacrificial layer is utilized in the process to simultaneously form symmetrical facing surfaces of relatively rotatable components. The facing surfaces define, therebetween, a desired feature, such as a journal bearing, a thrust bearing, a fluid channel, a fluid reservoir, a capillary seal, pressure generating grooves, and other profile geometries. Such geometry control allows for design freedom in obtaining a desired bearing performance and stiffness. | 12-02-2010 |
| 20110227523 | Direct Current Motor with Independently Driven and Switchable Stators - An apparatus and method are provided for adjusting torque and speed of a motor, while remaining within the voltage limit of a power supply. The invention provides a brushless direct current motor with independently driven and switchable stators. In an aspect, each stator and the rotor is structured to function as an independent motor separate from another stator and the rotor. A first power electronics directs energy to a first stator, and a second power electronics directs energy to a second stator. A rotor rotates relative to the stators. In an aspect, a commutation electronics determines electrical position of the rotor relative to the stators, and synchronizes current pulses directed to a sequentially selected phase of the stators, to generate a rotating magnetic field that communicates with the rotor. A controller sets the connection of the first power electronics in series or in parallel with the second power electronics. | 09-22-2011 |
