Abstract: An apparatus for rotatably journaling a rotor of a flat spindle motor about a stator comprising a spindle magnet disc disposed on the rotor assembly of the flat spindle motor and journaled about the spindle motor shaft having a disc shaped first magnetized region with an outer radius r comprised of a plurality of axial aligned poles, a disc shaped second region having an outer radius r2 (where r2>r) comprised of a single pole, and a disc shaped non-magnetized spacer region disposed there between. The integrated spindle magnet disc is disposed on the inside surface of a rotor over complementary axially aligned electromagnet poles which are disposed on the base of the stator assembly. A like aligned single pole is fixedly attached to the stator and disposed in opposition to the second magnetized region having like aligned pole of the integrated spindle permanent magnet.

Abstract: A magnetic crash stop and latch for limiting the motion of a transducer positioner assembly within a disc drive. The disc drive system has a transducer positioner assembly located within a housing for positioning one or more read/write transducers relative to a recording media within the housing. The apparatus includes components for latching an actuator assembly in a disc drive. A parking force is created by selectively attaching a small magnet (or one or two small ferrous metal slugs) to the end of the actuator arm portion of the actuator assembly having the voice coil motor (VCM). The small magnet (or slugs) operating in combination with the fixed magnetics of the VCM produces torque on the actuator assembly when the small magnet passes outside (or the slugs pass inside) of the magnetic field generated by the fixed magnetics. The resultant torque is utilized to move the actuator arm to contact a latch means.

Abstract: An "ironless" bearing spindle motor for rotating at least one disc about a central axis in a data storage device comprises a housing, a stationary member, a hub, and a stator. A rotor magnet is attached to the hub. A bearing interconnects the hub with the stationary member such that the hub and rotor magnet are rotatable about the central axis. The stator is coaxial with the hub and includes an ironless stator winding. The ironless stator winding minimizes low-harmonic acoustic vibration peaks in the spindle motor, resulting in a spindle motor having a very quiet operation.

Abstract: An apparatus for rotatably journaling a rotor of a spindle motor about a shaft comprising a plurality of annular ring multi-pole magnets, each ring comprised of a plurality of axially aligned magnets whose polarity is alternated along the radius of the ring. The annular ring multi-pole magnets are disposed on both the rotor and stator of a spindle motor in opposition in attraction mode, or a complete offset repulsion mode with like poles facing one another with an full offset, thereby forming a radially stable magnetic bearing for maintaining rotor displacement about a shaft in conjunction with a conventional axial pivot.

Abstract: 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.

Abstract: An apparatus for rotatably journaling a rotor of a spindle motor about a stator comprising a plurality of magnetic bearings for use in a disc drive including an annular ring single-pole magnet which is integral with the spindle permanent magnet of a spindle motor rotor assembly and disposed in opposition to a complementary annular magnet ring attached to the stator assembly of the spindle motor. These magnetic bearings in conjunction with an axial pivot form a radially stable bearing system for maintaining rotor displacement about the stator in conjunction with a conventional axial pivot. The present invention provides for the unique combination of magnetic bearings with other conventional pivots for use in disc drive systems.

Abstract: 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 well as a biased support flange.

Abstract: An apparatus for rotatably journaling a rotor of a spindle motor about a stator comprising a plurality of magnetic bearings for use in a disc drive including an annular ring single-pole magnet which is integral with the spindle permanent magnet of a spindle motor rotor assembly and disposed in opposition to a complementary annular magnet ring attached to the stator assembly of the spindle motor. These magnetic bearings in conjunction with an axial pivot form a radially stable bearing system for maintaining rotor displacement about the stator in conjunction with a conventional axial pivot. The present invention provides for the unique combination of magnetic bearings with other conventional pivots for use in disc drive systems.

Abstract: An apparatus for rotatably journaling a rotor of a spindle motor about a shaft comprising a plurality of annular ring multi-pole magnets, each ring comprised of a plurality of axially aligned magnets whose polarity is alternated along the radius of the ring. The annular ring multi-pole magnets are disposed on both the rotor and stator of a spindle motor in opposition in attraction mode, or a complete offset repulsion mode with like poles facing one another with an full offset, thereby forming a radially stable magnetic bearing for maintaining rotor displacement about a shaft in conjunction with a conventional axial pivot.

Abstract: A combination of a fixed and moving surface, which may in a common example comprise a rotating journal facing a thrust plate, characterized in that both parts are made of materials or material combinations chosen such that, as the temperature rises, the gap between the bearing surfaces becomes smaller due to the different thermal expansion of the relevant parts.The high coefficient expansion material includes a relatively shallow recess near the center of the bearing. This recess allows the expansion material to expand with temperature in order to decrease the gap and maintain the stiffness of the bearing. As the temperature rises, the fluid is forced out of the recess region and into the effective bearing gap thereby maintaining the overall stiffness of the bearing, which would otherwise fall as fluid viscosity drops.

Abstract: 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 sleeve, and a bearing unit. The bearing unit is operably coupled to the rotor hub and includes an inner race secured to the shaft, an outer race secured to the bearing sleeve, and bearing balls fitted between the inner race and the outer race. The bearing balls rotatably support the rotor hub about an axis. At least one structural element of the spindle motor has a high resistivity so as to electrically isolate the hub from the base. In another embodiment, the drive base has an interface surface for coupling with the spindle motor. The interface surface includes a layer of high resistivity material. In another embodiment, the bearing ball is made of ceramic or ruby material to improve performance characteristics.

Abstract: 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.

Abstract: A disc drive includes a disc drive motor for rotating a storage disc. The motor includes a motor base having a fixed member. A rotor is rotatably coupled to the fixed member and carries the storage disc. First and second bearings are positioned between the rotor and the fixed member allowing rotation of the rotor about the fixed member. A permanent magnet is positioned between the first and second bearings. A conductive fluid between the rotor and the fixed member is maintained in operable contact with the rotor and the fixed member by the permanent magnet. The ferrofluid provides a low resistance electrical path between the rotor and the fixed member thereby electrically grounding the rotor to the motor base.

Abstract: A voice coil motor (VCM) for a small form factor hard disk drive having a contoured flux field in the air gap wherein adjoining regions of oppositely directed magnetic flux form a transition zone. In the preferred embodiment, the magnetic structure assembly is contoured or shaped. The magnetic structure assembly comprises pole pieces and magnets. The shaping may be of either of the pole pieces or of either of the magnets. The shaping may be along the top edge only, along the bottom edge only, or along both edges. Alternatively, the shaping may be accomplished in the transverse plane, that is by shaping the profile in thickness. The shaping can be done so that when the flux is falling in one gap it is rising in the other gap. In this manner, the sum of the flux in the two gaps remains the same.

Abstract: Method and apparatus for providing a controlled resistance electrical path from one moving element of an electrical device to second or subsequent element. An electrically conductive media is introduced between the rotating and static element of an electrical device. The media, e.g. conductive grease, may be introduced into the bearings of the device. Alternatively, a housing may be disposed upon one of the elements. Into this housing is introduced a quantity of electrically conductive media and a contact element. The contact element is integral with, or is preloaded against, one end of the shaft of the second element, thereby forming an electrical path from the shaft, through the media to the housing and thence to the first element of the device. The contact element may be seen therefore to be floating in contact with the conductive media, thereby forming a controlled-resistance rotary electrical connector.

Abstract: The present invention is directed to the structure of the permanent pole pieces, the permanent magnets and the bobbin of a voice coil motor. The poles, poles and permanent magnet(s) or poles, permanent magnets or any combination thereof are shaped in such a manner as to provide as large and constant magnetic flux field strength over a given area. The shaping of the components of the voice coil motor results in an altered external geometrical shape of the voice coil motor envelope, a reduced envelope for a motor of a given torque capability or both. The shaping of the poles, permanent magnets or bobbin allows the voice coil motor to consume less room within the disk drive housing.

Abstract: The present method and apparatus detects the rotor position of a brushless DC motor with an accuracy of .pi./m electrical radians (where m = the number of motor phases) within one electrical period, and provides enough information to enable starting the motor in the correct direction with certainty. After starting the motor in an open loop mode of one or two steps, a closed loop mode may be switched on, using a dynamic indirect position detection as is already well known in the technology. More specifically, the position at start is determined by the injection of short current pulses in different motor phases, each phase or pair of phases being energized first by a pulse of one polarity and of the opposite polarity. The sign of the time difference between the decay times of the induced voltages in the un-energized phase is detected.

Abstract: The present method and apparatus detects the rotor position of a brushless DC motor with an accuracy of .pi./m electrical radians (where m=the number of motor phases) within one electrical period, and provides enough information to enable starting the motor in the correct direction with certainty. After starting the motor in an open loop mode of one or two steps, a closed loop mode may be switched on, using a dynamic indirect position detection as is already well known in the technology. More specifically, the position at start is determined by the injection of short current pulses in different motor phases, each phase or pair of phases being energized first by a pulse of one polarity and of the opposite polarity. The sign of the time difference between the rise times of the induced voltages is detected.

Abstract: An impact mechanism for an improved serial impact printer for delivering a printing force to drive a character element against a platen by means of a print tip movable toward and away from the platen. The print tip is supported upon a carriage mounted upon the printer for reciprocating movement in a path substantially parallel to the axis of the platen. The impact mechanism includes a bail bar extending substantially across the printer and mounted for rocking movement toward and away from the platen, its axis of rocking being substantially parallel to the axis of the platen. A prime mover is connected to the bail bar for imparting controlled rocking movement thereto. The print tip and the bail bar are interconnected so as to move the print tip toward and away from the platen as the bail bar is rocked.

Abstract: An impacting element for an impact printer having a platen, selectable character elements and means for driving the impacting element to impart a printing force to a selected character element, to drive it against said platen for a contact period, the impacting element including a sensor thereon for generating a signal indicative of the initiation of the contact period.