Abstract: Improved capillary sealing is provided for withstanding shock events, vibration and evaporation, for use with fluid dynamic bearings. In an aspect, minimal axial space is occupied by a fluid reservoir and the sealing system and method withstands at least 1000 G shock events. A fluid reservoir having a capillary surface is formed between diverging walls. A fluid fill pool, separate from the fluid reservoir and having a steeper angle than the fluid reservoir, is positioned adjacent to a fluid fill hole. The fill pool, having a greater diverging angle than the fluid reservoir provides an unstable region for fluid to remain and any fluid is pulled by capillary force gradient to the fluid reservoir.

Abstract: Hard disk drive track density is increased by selectively increasing the stiffness of a fluid dynamic bearing (FDB) motor during servo write. Applying a load to the shaft of a fixed shaft FDB motor to close the bearing gaps increases stiffness. Alternatively, the disk drive is cooled to increase bearing fluid viscosity or the motor is operated at an increased rotational velocity.

Abstract: The shaft may be supported for rotation by a conical bearing rotating within a sleeve. To prevent misalignment of the rotor and stator as the motor heats up and fluid viscosity changes, a magnetic preload is established; in a preferred embodiment, the magnetic preload is achieved using a magnetic back iron aligned with the stator magnet, the magnetic back iron being supported from the base. The shaft may further include a lower journal bearing for maintaining radial alignment and/or stiffness. A shaft may be supported for rotation relative to a sleeve by a combination of journal bearing and thrust bearing whose gaps are connected and grooved to cooperate. The bearing system includes a magnetic preload at the end of the shaft distal from the journal bearing/thrust bearing combination, the magnetic force balancing the spiral groove thrust bearing to maintain the bearing support for the shaft and the load (including hub and disc) that it supports.

Abstract: A fluid dynamic bearing motor assembly is described. In one embodiment, the assembly includes a shaft, a sleeve configured to rotate about a rotational axis, and a counterplate attached to the sleeve. The counterplate includes a radial section and a axial section, which is attached to the radial section and partially defines a labyrinth to remove bearing fluid from a region between the shaft and the axial section.

Abstract: A method and apparatus for assembling a hydrodynamic bearing in a motor is provided. The method comprises affixing a first bearing upon a shaft, applying an axial tension force to the shaft, and affixing a second bearing upon the shaft in a spaced apart relation to the first bearing, as the axial force is applied to the shaft.

Abstract: An improved rotational motor, such as a spindle motor for a disc drive, is provided. The motor first comprises a hub having a shaft portion and a horizontal body portion. The motor also comprises a sleeve surrounding the shaft portion of the hub. A fine first vertical gap is retained between the shaft and the inner diameter of the surrounding sleeve. In addition, a fine horizontal gap is provided between the upper hub portion and the top of the sleeve. A third gap is preferably provided between the hub and an outer diameter of the sleeve. The first vertical gap is filled with a lubricating liquid, such as a clean oil. A capillary seal is provided in the third gap. In one embodiment, the lubricating liquid extends into the horizontal gap. Oil pumping grooves are machined along the horizontal fluid gap. When the hub is rotated, the oil pumping grooves impel oil towards the shaft. This prevents any portion of the first vertical gap from becoming un-lubricated during rotation of the shaft.

Abstract: A fluid dynamic bearing motor is described. In one embodiment, the fluid dynamic bearing motor includes a base that has a bore hole and a liner secured within the bore hole. The fluid dynamic bearing motor also includes a rotor assembly that has a shaft, which is partially disposed within the liner and configured to rotate relative to the liner. A fluid dynamic bearing is disposed between the liner and the shaft to support this relative rotation.

Abstract: A fluid dynamic bearing motor assembly is described. In one embodiment, the assembly includes a shaft, a sleeve configured to rotate about a rotational axis, and a counterplate attached to the sleeve. The counterplate includes a radial section and a axial section, which is attached to the radial section and partially defines a labyrinth to remove bearing fluid from a region between the shaft and the axial section.

Abstract: Improved capillary sealing is provided for withstanding shock events, vibration and evaporation, for use with fluid dynamic bearings. In an aspect, minimal axial space is occupied by a fluid reservoir and the sealing system and method withstands at least 1000 G shock events. A fluid reservoir having a capillary surface is formed between diverging walls. A fluid fill pool, separate from the fluid reservoir and having a steeper angle than the fluid reservoir, is positioned adjacent to a fluid fill hole. The fill pool, having a greater diverging angle than the fluid reservoir provides an unstable region for fluid to remain and any fluid is pulled by capillary force gradient to the fluid reservoir.

Abstract: The present invention is related to a disk drive hub/back iron configuration that resists distortion upon changinging temperature of the disk drive. The hub/back iron configuration thus prevents distortion of the disks, reducing HDI problems.

Abstract: A hub and shaft are provided which are mounted for relative rotation by providing two conical bearings spaced apart along the shaft, and a bearing seat facing each conical bearing. Fluid is maintained in the gap between each cone and the facing bearing seat, supporting the cone and seat for relative rotation. The outer surface of the bearing seat is insulated from the remainder of the motor by a thermal insulator which extends at least part way along the outer surface of the seats. This insulator is effective at keeping the bearings warm even in a relatively low temperature environment in which the motor may be used. The insulator may comprise a cylindrical ceramic or similar low thermal conductivity material extending at least part way along the axial distance outside of the bearing cones. Alternatively, an air space may be defined in the outer surface of the bearing seat, extending at least part way between the bearing cones.

Abstract: The present invention relates to the field of fluid dynamic bearings. Specifically, the present invention provides a secondary fluid reservoir for the fluid used in a fluid dynamic bearing in a high-speed spindle motor assembly.

Abstract: The present invention is related to a disk drive hub/back iron configuration that resists distortion upon changinging temperature of the disk drive. The hub/back iron configuration thus prevents distortion of the disks, reducing HDI problems.

Abstract: A motor is provided comprising a rotor, a stationary sleeve disposed about the rotor, a fluid dynamic bearing between the rotor and sleeve, and a limiter for restricting axial movement of the rotor relative to the stationary sleeve.

Abstract: The present invention relates to the field of fluid dynamic bearings. Specifically, the present invention provides a secondary fluid reservoir for the fluid used in a fluid dynamic bearing in a high-speed spindle motor assembly.

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 method and apparatus for assembling a hydrodynamic bearing in a motor is provided. The method comprises affixing a first bearing upon a shaft, applying an axial tension force to the shaft, and affixing a second bearing upon the shaft in a spaced apart relation to the first bearing, as the axial force is applied to the shaft.

Abstract: The shaft may be supported for rotation by a conical bearing rotating within a sleeve. To prevent misalignment of the rotor and stator as the motor heats up and fluid viscosity changes, a magnetic preload is established; in a preferred embodiment, the magnetic preload is achieved using a magnetic back iron aligned with the stator magnet, the magnetic back iron being supported from the base. The shaft may further include a lower journal bearing for maintaining radial alignment and/or stiffness.

Abstract: To accurately locate a fluid dynamic bearing element along a shaft, the shaft is excited at or near its resonant frequency while applying a press force to the shaft, and holding the bearing element still. The assembly process then becomes a dynamic process, with the result that the positioning or locating of the shaft relative to the cone or other bearing element can be achieved with much greater accuracy.

Abstract: Hard disk drive track density is increased by selectively increasing the stiffness of an FDB motor during servo write. Applying a load to the shaft of a fixed shaft FDB motor to close the bearing gaps increases stiffness. Alternatively, the disk drive is cooled to increase bearing fluid viscosity or the motor is operated at an increased rotational velocity.