Seagate Technology Incorporated

Seagate Technologies, Inc.

John C Dunfield

Gunter Karl Heine

Kamran Oveyssi

Klaus Dieter Kloeppel

Robert Michael Pelstring

Clifford T Jue

Marcel Jufer

Frederick Frank Kazmierczak

Donald J MacLeod

Michael John Raffetto

Michael Kenneth Andrews

Steven C Knoche

Norbert Steven Parsoneault

Alan Lyndon Grantz

Michael Bruce Moir

Richard G Krum

Thomas A Hickox

Jeffrey P Stram

Gregory James Blanchette

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.

Microactuator for fine positioning in a disc drive

A brushless permanent-magnet direct current motor has a permanent magnet which is magnetized to create an offset angle between detent and mutual torques for providing sufficient starting torque for all relative orientations between the stator and the rotor of the motor. This is accomplished by providing a permanent magnet in which the global magnetization of the magnet has been disrupted by the application of a local magnetic field to a portion of the magnet, thereby to provide a magnetic anomaly in the global magnetization. Also, a method of magnetization of the magnet is described.

Method of magnetizing a ring-shaped magnet

A motor is disclosed which includes a shaft and a hub rotating relative to one another and defining a bore therebetween. Also disclosed is a magnetic fluid seal which includes pole pieces supported from the hub, the pole pieces extend toward the shaft. The pole pieces sandwich a non-conducting magnet in a space between the pole pieces. In addition, a contacting process is supported from one of the pole pieces for making electrical contact with the other pole piece to enhance electrical conductivity between the hub and shaft.

Grounding and conductivity improvement for ferrofluid seals

A magnetic disc drive system includes a hydrodynamic bearing. The magnetic disc drive system includes a disc drive chassis, a magnetic storage disc, and a read/write transducer adjacent to the disc for reading and writing information on the disc. The hydrodynamic bearing assembly rotatably couples the magnetic storage disc to the disc drive chassis. The hydrodynamic bearing assembly includes a fluid path therethrough for circulating a fluid. A permanent magnet is placed in the fluid path and used for attracting magnetic particles carried in the fluid.

Magnetic disc drive having magnetic particle trap for hydrodynamic

A spindle motor assembly adapted for rotationally supporting a load about a base includes a rotor rotatably mounted on the base with its outer periphery capable of supporting a load, a stator and a plurality of magnets mounted on the outer periphery of the rotor. The stator includes a plurality of stator laminations with selective portions of the stator laminations forming stator cores. A plurality of magnets are mounted on the outer periphery of the rotor in an operating relationship with the stator cores. A plurality of conductors are wound on the stator cores. The stator includes a resilient covering located around the plurality of laminations and further having a routing means to route the conductors between the stator cores, an attaching means to attach the stator to the base and a connecting means. The connecting means includes a first connector block with a plurality of first conductor pads, with a first end and a second end. Ends of the conductors are connected to the first end of the conductor pads. A second connector block is mounted on the base, with the second connector block having a plurality of second conductor pads. The second end of the first conductor pads are connected to the second conductor pads of the second connector block.

Disk drive spindle motor assembly with stator having a resilient

A rotating shaft motor or cartridge incorporates an o-ring which surrounds the rotating shaft and is borne on a carrier. As supported on the carrier, the o-ring does not normally block the bearing passages which would prevent the smooth distribution of oil throughout the motor. However, the carrier and o-ring combination are designed to allow the o-ring to be forced into an opening between the shaft and sleeve for completely sealing the remaining portion of the bearing during filling. The rotating shaft includes a central reservoir, having one or more grooves or passages communicating with the hydrodynamic bearing surfaces and ending in a septum or rubber plug which is inserted in an opening in the shaft.

Oil filling seal for hydrodynamic motor utilizing a movable sealing

A hydrodynamic bearing is disclosed which includes a shaft and a rotor rotating relative to one another and defining a hydrodynamic bearing in the gap between the relatively rotating parts. Also disclosed is a method for identifying or signaling potential failure of the hydrodynamic bearing. The method for identifying or signaling potential failure includes a capacitance detector for generating a signal representing the capacitance across the gap defining the hydrodynamic bearing, a comparator for comparing the capacitance to an established threshold, and an indicator for providing a signal indicating that operation of the information storage device incorporating the hydrodynamic bearing should continue or that an interruption is likely.

Hydrodynamic bearing including means for monitoring the capacitance

The spindle motor is integrated with the disc by incorporating one of the poles or coils of the motor with a region on the disc, and the remaining portion of the motor being distributed over an internal surface or surfaces of the housing for the disc, or over the edge of an adjacent disc. By activating the portion of the motor which is supported from the disc housing, the disc can be rotationally driven. The motor poles may be either deposited or etched on the disc, or separately formed and attached to the disc housing. The result is a substantially smaller height disc drive, achieved with a much reduced cost.

Distributed spindle motor integrated with disc

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. The rotor magnet, back-iron and stator winding have a common axial position along the central axis and the stator winding is magnetically coupled to the rotor magnet such that the stator winding and the rotor magnet cooperate to reduce excitation of pure tone vibrations in the disc drive data storage system and to reduce transfer of the vibrations to the housing through the ball bearing assemblies.

Slotless spindle motor for disc drive

A disc drive for storing and retrieving data from at least one memory storage disc includes a drive base and a spindle motor. The spindle motor includes a rotor hub, a shaft, a bearing unit. The bearing unit rotatably supports the rotor hub about an axis. A controlled resistance electrical pathway is established from the rotor hub to ground to control disc potential and to prevent excess static charge buildup. In one embodiment, the spindle motor includes structural elements made of a conducting plastic having a controlled resistance to establish a controlled resistance electrical pathway from the rotor hub to ground. In a second embodiment, the shaft of the spindle motor includes a conductive contact button electrically connected to the shaft and operatively coupled with a contact shield electrically grounded by an electrical conductor having a controlled resistance. In another embodiment, the spindle motor includes a rod made of conductive material extending from an electrically grounded contact shield and received within the shaft. An electrical pathway between the shaft and the rod is established by a conducting fluid between the rod and the shaft. Alternatively, the electrical pathway from the shaft to the rod is established by a conducting unit. The conducting unit includes a seal, a magnetic conductive material, and a ferro-fluid. The seal is positioned within the shaft. The magnetic conductive material is coupled to the rod. The ferro-fluid is supported between the seal and the magnetic conductive material.

Disc drive spindle motor with controlled resistance pathway from disc to

A microprocessor-controlled-circuit applies pulses to a standing motor whose rotor position is to be determined. The time required for the injected current to reach a predetermined threshold in a comparator is measured. The pulses are long enough to effectuate an accurate measurement, but not so long that the rotor moves. The pulse is applied twice to each phase, once with a positive polarity and once with a negative polarity, for a total of six measurements. The positive and negative rise times are subtracted from each other to determine whether the positive or negative current rise time was greater. Based upon the differences in the readings for all of the phases, the position of the rotor is known. There are differences in which the difference is zero or negligible. There are at least two methods to determine rotor position when there are ambiguities in the sign of the difference. In one method, the combination of the sign of the rise time difference or its absence plus the magnitude of the rise time can be used along with look-up tables to determine the rotor position. Another method is to resolve a position uncertainty by changing the effective rotor position. This is done by pulsing all three phases actively. Instead of leaving a phase open during pulsing, the third phase is tied high or is tied low. Once start-up ambiguities are resolved, control of acceleration from stand-still through medium speed to constant, nominal speed is provided.

Detection of starting motor position in a brushless DC motor

Spindle motor electrical- and motor-to-base interfaces. A compliant connector along with a circuit on a support flange is provided below a stator assembly for providing: An insertable spindle motor to drive base with less specific orientation. The support flange may comprise a small printed circuit cable or a printed circuit board. Additionally, non-specific orientation of a spindle motor to drive base assembly is described using circular traces oriented about a support flange. A circular connector is also described, as a biased support flange.

Support flange having electrical contacts to provide electrical

A disc drive cartridge is disclosed comprising a central actuator arm pivot hub mounting one magnetic pole, which in turn rotates within and overlaps a u-shaped upright base and sleeve supporting a second non-aligned magnetic pole. The system relies on the radial repulsive forces of the separate magnetic poles to achieve significant radial stability; in certain embodiments, attractive forces between axially aligned magnetic poles or a magnetic pole and a sleeve of high permeability magnetic material are also utilized to enhance the axial stability of the system. The rotating hub supports on one side one or more actuator arms and on the other side a coil of a voice coil motor, so that this magnetic bearing can be the central pivot for a very small compact and low noise disc drive cartridge.

Disc drive cartridge including magnetic bearings

A disc drive includes a disc drive motor for rotating a storage disc. The motor includes a motor base which carries a wiring assembly having a plurality of electrical contacts. A rotor hub is rotatably coupled to the base and rotatably carries a storage disc. The rotor hub includes a permanent magnet. A stator assembly includes a plurality of stator windings adapted for operation with the permanent magnet of the rotor hub. A wire guide coupled to the stator assembly positions wires of the stator windings adjacent the electrical contacts of the wiring assembly. The wires are soldered to the contacts after which the wiring guide can be removed. The stator assembly can be 'potted' in an adhesive to reduce problems associated with resonant frequency of the disc drive motor. The wire guide acts as a retainer for the adhesive preventing the adhesive from interfering with rotation of the rotatable hub.

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Santa Cruz, CA, United States of America

John C Dunfield