Abstract: A system and method are described for ballizing and measuring a workpiece bore hole. In one embodiment, a ballizing unit having a distal end removably coupled to a ballizing member moves the ballizing member from a first position within the bore hole to a second position. A metrology unit having a distal end removably coupled to the ballizing member moves the ballizing member from the second position back to the first position. A sensor detects a force exerted on the ballizing member by the workpiece at a third position, which is located between the first and second positions.

Abstract: A system and method are described for ballizing and measuring a workpiece bore hole. In one embodiment, a ballizing unit having a distal end removably coupled to a ballizing member moves the ballizing member from a first position within the bore hole to a second position. A metrology unit having a distal end removably coupled to the ballizing member moves the ballizing member from the second position back to the first position. A sensor detects a force exerted on the ballizing member by the workpiece at a third position, which is located between the first and second positions.

Abstract: A circular magnetizer is disclosed comprising circular insulating inset holding pans of axially disposed wires, each pair carrying a current oppositely directed from the adjacent pair, the insert being disposed within and facing a back iron across a circular gap of sufficient width to allow a circular magnet to be disposed therein and spaced by a gap from the insert and/or back iron. The pan's of wires are arranged to create flux lines which will establish alternating magnetic poles separated by null zones in the magnet.

Abstract: An actuator arm assembly is provided in a disc drive. The disc drive includes a disc with a surface for storing information and a first actuator for moving the actuator arm assembly relative to the surface of the disc. The actuator arm assembly includes an actuator arm coupled to the first actuator, a load beam coupled to the actuator arm, a suspension coupled to the load beam and an air bearing coupled to the suspension. A transducer is mounted on the air bearing and positioned to access the surface of the disc. A second actuator is coupled to the air bearing and the load beam and is controllable to move the air bearing relative to the surface of the disc and relative to the load beam.

Abstract: An actuator arm assembly is provided in a disc drive. The disc drive includes a disc with a surface for storing information and a first actuator for moving the actuator arm assembly relative to the surface of the disc. The actuator arm assembly includes an actuator arm coupled to the first actuator, a load beam coupled to the actuator arm, a suspension coupled to the load beam and an air bearing coupled to the suspension. A transducer is mounted on the air bearing and positioned to access the surface of the disc. A second actuator is coupled to the air bearing and the load beam and is controllable to move the air bearing relative to the surface of the disc and relative to the load beam.

Abstract: A discrete fluid dynamic bearing comprising a fluid dynamic bearing including a bearing cone mounted on a sleeve and defining in cooperation with a bearing seat having a surface facing an outer surface of the bearing cone across a fluid bearing gap, a first seal establishing a pressure gradient from a distal end of the sleeve toward the gap of the fluid dynamic bearing and a second seal on an opposite side of the fluid dynamic bearing from the first seal for establishing a positive, higher pressure toward the fluid bearing gap, the press established by the first and second seals maintain the fluid in the gap during relative rotation of the surfaces of the fluid dynamic bearing.

Abstract: A method of creating an improved hydrodynamic fluid bearing is provided which is relatively insensitive to shock vibration changes in load and rotational speed. The hydrodynamic bearing motor in which the bearing is open at both the upper and lower ends, and in which the balance of fluid flow within the bearings is maintained. The assembly of the hydrodynamic bearing is more easily assembled, and the gaps are easily adjusted. In the design of the hydrodynamic bearing, the tolerances for assembly of the various components is minimized; that is, the critical nature of many of the gaps is diminished.

Abstract: A hydrodynamic fluid bearing useful in a bearing cartridge which cartridge may be incorporated into a spindle motor or the like, where the bearing includes a shaft, a conical bearing supported on the shaft, and journal bearings located at least on one side and typically both above and below the conical bearing. A sleeve is mounted for rotation relative to the shaft and defines, in cooperation with the shaft, the gaps necessary for both the conical hydrodynamic bearing and the axial, journal bearings. At an end of the shaft, capillary seals are defined between the sleeve and the shaft so that fluid does not escape from the hydrodynamic bearing. The shaft itself includes a central hole, with bores communicating with both the conical bearing and the journal bearings to maintain appropriate pressure balances.In a further desirable feature, in some embodiments the diameter of one end of the shaft can be made greater than the diameter of the other end of the shaft.

Abstract: A method of creating an improved hydrodynamic fluid bearing is provided which is relatively insensitive to shock vibration changes in load and rotational speed. The hydrodynamic bearing motor in which the bearing is open at both the upper and lower ends, and in which the balance of fluid flow within the bearings is maintained. The assembly of the hydrodynamic bearing is more easily assembled, and the gaps are easily adjusted. In the design of the hydrodynamic bearing, the tolerances for assembly of the various components is minimized that is, the critical nature of many of the gaps is diminished.

Abstract: A spindle motor in a disc drive has a rotor assembly rotatably mounted to a base. A stator is mounted to the base and a magnet is mounted to the rotor assembly. The magnet or the stator is allowed to move in an axial direction relative to the other under the influence of magnetic interaction between the magnet and the stator. The magnet and stator are then rigidly fixed relative to one another in the axial direction.

Abstract: A method to create an improved hydrodynamic bearing which is relatively insensitive to changes in load and rotational speed is provided, wherein the hydrodynamic bearing is useful in a spindle motor for a disc drive or the like which is stiffer than known standard spindle motors so that the stability of the system and specifically of the actuator arm and transducer relative to the rotating disc is optimized. The hydrodynamic bearing can also be used as a bearing cartridge or as the cartridge that may be incorporated into a spindle motor or the like, where the bearing includes a shaft and at least two independent bearings each comprising a thrust plate supported on the shaft and a counter plate incorporated in a sleeve which is capable of relative rotation around the shaft.

Abstract: The third dynamic bearing includes a fixed shaft and a sleeve rotating around and surrounding the shaft, and at least first and second thrust plates separated by a portion of the shaft. The shaft includes an axial hole to vent appropriate positions inside the bearing. The axial hole extends from one end of the shaft past at least one of the thrust plates. The axial hole is connected by a radial bore to the bearing gap at a location between the thrust plate closest to that one end of the shaft and the facing counterplate.Alternatively, the axial hole can extend beyond the farthest thrust plate from the one end of the shaft, and can be connected to the bearing gap by a second radial cross-bore. A meniscus forms in the bearing gap on either side of each vent opening, decoupling adjacent bearing sections of the hydrodynamic bearing.

Abstract: A method to create an improved hydrodynamic bearing which is relatively insensitive to changes in load and rotational speed is provided, wherein the hydrodynamic bearing is useful in a spindle motor for a disc drive or the like which is stiffer than known standard spindle motors so that the stability of the system and specifically of the actuator arm and transducer relative to the rotating disc is optimized. The hydrodynamic bearing can also be used as a bearing cartridge or as the cartridge that may be incorporated into a spindle motor or the like, where the bearing includes a shaft and at least two independent bearings each comprising a thrust plate supported on the shaft and a counter plate incorporated in a sleeve which is capable of relative rotation around the shaft.

Abstract: The hydrodynamic bearing gap from one end to the other of the shaft and sleeve combination is effectively separated into sections, with the fluid in each bearing section being contained within that section. The viscosity of the fluid in each bearing section can then be selected to optimize the characteristics of the entire hydrodynamic bearing. Typically, the sections of the bearing adjacent each open end of the bearing would be filled with a fluid with relatively high viscosity. The remaining sections, toward the center of bearing, would typically be filled with a lower viscosity fluid, liquid or gas so that the power consumption within the motor itself would be minimized.

Abstract: A disc drive data storage system according to the present invention comprises 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. At least one data storage disc is attached to and is coaxial with the rotatable member. Upper and lower ball bearing assemblies interconnect the stationary member and the rotatable member. At least one rotor magnet is attached to the rotatable member. A back-iron is supported by the stationary member. A stator winding is attached to the back-iron and has a slotless structure.

Abstract: A disc drive spindle motor for rotating at least one disc in a data storage device includes a base, a shaft, a rotor and a stator. A bearing interconnects the rotor with the shaft and allows the rotor to rotate about the shaft. An overmold encapsulates at least a portion of the stator and provides the stator with a smooth external surface. The overmold mechanically isolates the stator from the base and damps sympathetic vibrations in the stator structure to reduce the generation of acoustic noise in the storage device.

Abstract: A spindle motor in a disc drive has a rotor assembly rotatably mounted to a base. A stator is mounted to the base and a magnet is mounted to the rotor assembly. The magnet or the stator is allowed to move in an axial direction relative to the other under the influence of magnetic interaction between the magnet and the stator. The magnet and stator are then rigidly fixed relative to one another in the axial direction.