Abstract: A system and method are provided for reduced power consumption and reduced wear in a spindle motor. The spindle motor includes a fluid dynamic bearing containing gas defined between a stationary component and a rotatable component. A liquid layer is coated on at least a portion of at least one of the rotatable component surface and the stationary component surface. The liquid layer is formed from a liquid having a predetermined concentration, and formed having a predetermined thickness. The predetermined thickness is accomplished utilizing at least one of a predetermined dwell time, withdraw velocity and bearing surface roughness. In an aspect, the liquid layer is formed with an increased thickness by at least one of increasing the liquid concentration, increasing the dwell time, and increasing the withdraw velocity. In an aspect, a method is provided to obtain thin liquid film thicknesses ranging from about 5 nm to about 350 nm.

Abstract: For motors having a journal with one or more groove regions and a shaft for relative rotation in the journal, aspects include providing a dual tapered shaft. The shaft may be tapered by the application of a wear resistant coating at least opposite the groove regions. The coating introduces a shaft taper from near a top end and from near a bottom end towards the shaft middle. The shaft taper may provide for improved pumping efficiency. The coating may be applied in various processes such as chemical vapor deposition or physical vapor deposition to establish a thickness gradient of coating material from near the top end and near the bottom end towards the shaft middle. In one example, the coating includes a DLC coating. Additionally, shaft portions may be shielded to prevent coatings thereon.

Abstract: For motors having a journal with one or more groove regions and a shaft for relative rotation in the journal, aspects include providing a dual tapered shaft. The shaft may be tapered by the application of a wear resistant coating at least opposite the groove regions. The coating introduces a shaft taper from near a top end and from near a bottom end towards the shaft middle. The shaft taper may provide for improved pumping efficiency. The coating may be applied in various processes such as chemical vapor deposition or physical vapor deposition to establish a thickness gradient of coating material from near the top end and near the bottom end towards the shaft middle. In one example, the coating includes a DLC coating. Additionally, shaft portions may be shielded to prevent coatings thereon.

Abstract: A seal with a primary axis lying in the radial direction so that the fluid bearing is primarily extending in the axial direction between the rotating shaft and surrounding sleeve is disclosed. The capillary seal is positioned with an opening adjacent an end of the fluid bearing gap, and comprises two walls which diverge as they extend radially away from the fluid bearing so that the fluid held in the radial capillary seal is maintained adjacent an end of the gap, while the size of the reservoir defined by the diverging walls provides a large reservoir volume. The seal uses an additional capillary defined by a narrow annulus between the rotating shaft and a seal wall end. The narrow annulus establishes very high shock resistance preventing fluid loss past the outer axial wall of the radially capillary seal, and defines a small surface area from which evaporation can occur.

Abstract: A disc drive storage system including a housing having a central axis, a stationary member that is fixed with respect to the housing and coaxial with the central axis, and a rotatable member that is rotatable about the central axis with respect to the stationary member. A hydro bearing interconnects the stationary member and the rotatable member and includes a lubricating fluid having a base fluid and an additive and/or a combination of additives or base fluids for reducing the temperature dependency of the viscosity of the lubricating fluid.

Abstract: A motor or bearing which incorporates the use of a capillary seal adjacent a bearing race between the shaft and surrounding hub or housing. The seal may take a plurality of forms, including a straight capillary seal; a seal formed between the housing and a seal ball having different radius of curvatures (preferably with the housing internal surface having a larger radius); or a centrifugal capillary seal comprising a male cone supported on a fixed or rotating shaft, and a female cone supported on a housing. The use of a capillary seal rather than ferrofluid seal should also provide a reduction in resistance across the seal gap compared to a ferrofluid seal.

Abstract: A disc drive storage system including a housing having a central axis, a stationary member that is fixed with respect to the housing and coaxial with the central axis, and a rotatable member that is rotatable about the central axis with respect to the stationary member is described. A hydrodynamic bearing interconnects the stationary member and the rotatable member and includes at least one working surface comprising a wear resistant coating.

Abstract: A seal whose primary axis lies in the radial direction where the fluid bearing is primarily extending in the axial direction between the rotating shaft and surrounding sleeve. The capillary seal is positioned with an opening adjacent an end of the fluid bearing gap, and comprises two diverging walls, with the narrowest gap between the two generally radially extending walls being closely adjacent an end of the fluid gap. The walls diverge as they extend radially away from the fluid bearing. In this way, the fluid held in the radial capillary seal is maintained adjacent an end of the gap, while the size of the reservoir provided or defined by the diverging walls provides a relatively large reservoir volume.

Abstract: A disc drive storage system including a housing having a central axis, a stationary member that is fixed with respect to the housing and coaxial with the central axis, and a rotatable member that is rotatable about the central axis with respect to the stationary member is described. A hydrodynamic bearing interconnects the stationary member and the rotatable member and includes at least one working surface comprising a wear resistant coating.

Abstract: A disc drive storage system including a housing having a central axis, a stationary member that is fixed with respect to the housing and coaxial with the central axis, and a rotatable member that is rotatable about the central axis with respect to the stationary member. A hydro bearing interconnects the stationary member and the rotatable member and includes a lubricating fluid having a base fluid and an additive and/or a combination of additives or base fluids for reducing the temperature dependency of the viscosity of the lubricating fluid.

Abstract: A disc drive storage system includes a housing having a central axis, a stationary member that is fixed with respect to the housing and coaxial with the central axis, and a rotatable member that is rotatable about the central axis with respect to the stationary member. A hydro bearing interconnects the stationary member and the rotatable member. The hydro bearing components are formed with a gall resistant material to prevent galling between working surfaces of the disc drive system.

Abstract: A non-reactive hard coating of carbon or ceramic is applied to the major components of the spindle motor which are exposed to the atmosphere internal to the hard disc drive. By having such a thin layer of carbon or other ceramic coating, it will protect against outgassing of motor components and create a neutral or non-reactive surface that does not promote corrosion. The coating thickness can be preferably in the order of nanometers to microns depending upon the drive design and the operating conditions.

Abstract: A reduced stiction hydrodynamic spindle motor is provided for reducing the starting torque or power of disc drive motors. The reduced stiction motor includes a low surface energy coating having a surface energy less than the surface tension of the motor lubricant.

Abstract: A spindle motor is described having a motor stator, a motor rotor, the motor being energized to cause rotation of the rotor supporting a single disc or a stack of discs which is mounted in such a way that the rotating bottom or top (or both) disc surface is closely adjacent to a stationary disc drive casting surface. The squeeze film action in the remaining air gap provides significant damping of the disc vibration. Typical implementation use air gaps of 0.004″-0.006″ for 2½″ drives and 0.006″-0.10″ for 3½″ drives.

Abstract: 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).

Abstract: A hydrodynamic bearing design is disclosed incorporating a flexible membrane at one end of the fluid gap in the hydrodynamic bearing. If voids exist in the fluid, and if changes in the size of these voids or bubbles occur with changes in temperature or pressure in which the disc drive is being used, then the volume of the fluid will change, and increase relative to the change in size of the volume of the surrounding physical part. The flexible membrane will yield to the increased pressure of the increasing volume of the fluid. The membrane essentially acts as a spring whose spring force is overcome by the pressure created by or accompanying a increase in volume in which the lubricating fluid is contained, and preventing its escape or being forced out of the inner region of the bearing.

Abstract: A disc drive data storage system according to the present invention includes a stationary member, a rotatable member and a hydro bearing which interconnects the stationary member and the rotatable member. At least one data storage disc is attached to and is coaxial with the rotatable member. The hydro bearing includes an electrically non-conductive lubricant and an electrically conductive, non-metallic additive.

Abstract: A disc drive data storage system according to the present invention includes a housing, a central axis, a stationary member which is fixed with respect to the housing and coaxial with the central axis, and a rotatable member which is rotatable about the central axis with respect to the stationary member. A stator is fixed with respect to the housing. A rotor is supported by the rotatable member and is magnetically coupled to the stator. At least one data storage disc is attached to and is coaxial with the rotatable member. A hydro bearing interconnects the stationary member and the rotatable member and includes a blend of base fluids. The base fluids in the blend are selected such that one of the base fluids has a viscosity that is greater than a desired viscosity selected for the disc drive, another of the base fluids has a viscosity that is less than the desired viscosity and the blend of base fluids has a viscosity that is within a selected range of the desired viscosity.

Abstract: A disc drive data storage system according to the present invention includes a housing, a central axis, a stationary member which is fixed with respect to the housing and coaxial with the central axis, and a rotatable member which is rotatable about the central axis with respect to the stationary member. A stator is fixed with respect to the housing. A rotor is supported by the rotatable member and is magnetically coupled to the stator. At least one data storage disc is attached to and is coaxial with the rotatable member. A hydro bearing interconnects the stationary member and the rotatable member and includes a blend of a base fluid having a viscosity index of at least 110, an anti-oxidant additive, anti-corrosion additive and an anti-wear additive, which are effective for resisting catalytic degradation in the hydro bearing.

Abstract: A disc drive includes a disc drive motor and a chassis for providing a substantially contaminant-free cavity. The disc drive motor includes a fixed member coupled to the chassis and a rotor rotatable about the fixed member for rotating a magnetic storage disc in the contaminant-free cavity. A bearing interconnects the fixed member and the rotor. A viscous pump seal is located between the contaminant-free cavity and the bearing. The viscous pump seal includes a first pump surface carried by one of the fixed member and the rotor and a second, grooved pump surface carried by the other of the fixed member and the rotor. The first and second pump surfaces are separated by a gap. The viscous pump seal inhibits transfer of contaminants from the bearing to the contaminant-free cavity.