Maxtor Corporation

Disctron, Inc.

Other

Harold T Wright

Robert David Freeman

William O'Sullivan

A thermally independent dedicated servo disk drive where the temperature is kept within an acceptable range and temperature gradients that can cause differential thermal expansion are eliminated to minimize off tracking due to differential thermal expansion of thermally sensitive components. A novel isolated 'box within a box' architecture is utilized to provide a thermal buffer to external temperature gradients and an inner HDA support structure is coupled to an outer housing with thermally insulative isolators which prevent the conductive transfer of heat from external sources where the outer housing and isolators create a thermal buffer to shield the inner HDA support structure from external heat sources. In addition, certain heat generating components not integrated into the symmetrical thermal 'box within a box' design are isolated where possible. Thus, a thermally symmetrical environment is provided in the area of thermally sensitive components that could otherwise degrade tracking during temperature transients.

Method and apparatus for improved thermal isolation and stability of

An in-spindle disk drive motor incorporating a novel two-piece aluminum spindle and a method for fabricating the same. The spindle is hollow and contains a removable steel flux sleeve on which plastic permanent magnets are mounted. The spindle is mounted by means of two bearings to a non-rotating stator shaft disposed through the center of the spindle and rigidly attached to a disk drive base. One of the bearings is located in a removeable bearing sleeve at the top of the spindle and the other is located beyond the steel sleeve at the bottom end of the spindle. The aluminum spindle eliminates thermal distortion effects caused in prior art in-spindle motors by thermal expansion differences between aluminum disks and non-aluminum spindles.

In-spindle motor assembly for disk drive and method for fabricating

An in-spindle disk drive motor incorporating a novel two-piece aluminum spindle and a method for fabricating the same. The spindle is hollow and contains a removable steel flux sleeve on which plastic permanent magnets are mounted. The spindle is mounted by means of two bearings to a non-rotating stator shaft disposed through the center of the spindle and rigidly attached to a disk drive base. One of the bearings is located in a removable bearing sleeve at the top of the spindle and the other is located beyond the steel sleeve at the bottom end of the spindle. The aluminum spindle eliminates thermal distortion effects caused in prior art in spindle motors by thermal expansion differences between aluminum disks and non-aluminum spindles.

In-spindle motor assembly for disk drive and method for fabricating the

Disk drive motor with thermally matched parts

A Winchester disc spindle construction provides a spindle motor coil wound around laminated formed annular plates and having lead wires extending through a central stationary shaft. Surrounding a spindle coil is a cylinder having a pocket for arcuate permanent magnets. The discs are fixed to and rotated by the cylinder. Relatively large bearings support the cylinder concentric with the shaft and give increased strength to the structure, permitting more discs to be supported in equivalent space, as compared with prior structures. The arms carrying the read-write heads are mounted on a stack of spaced-apart arms pivotted at a distance from the discs so that the heads move along a shallow arc to reduce skewing of the heads relative to the recording tracks of the discs. To reduce overall size of the drive structure (and permit such shallow arc movement) the arm actuator coil is fixed to the arms with its major axis parallel to the pivot axis, as contrasted with prior structures where the major axis of the coil is transverse to the pivot axis. The arms are statically balanced for improved action. A latch to hold the arms stationary when power is off and over-travel limit means are provided.

Winchester disc drive actuator structure

In a Winchester hard disk drive assembly having at least one disk rotatably disposed on a cylindrical spindle, the improvement compromising spacer means interposed between the inner diameter of said at least one disk and the outer diameter of said cylindrical spindle, said spacer means defining a clearance between said at least one disk and said spindle and adhesive means for adhesively securing said spacer means between said spindle, and said at least one disk, whereby a substantially uniform and contiguous clearance is maintained about the circumference of the spindle upon thermally induced differential expansion of the disk, and whereby said disk will be substantially prevented from abutting the outer circumferential wall of the spindle.

Method and apparatus for controlling radial disk displacement in

To overcome problems of precise permanent location of aluminum Winchester discs relative to their steel drive spindle during temperature variations, in one form of the invention a plastic washer is placed between the disc and the underlying flange of the spindle. The washer maintains contact by static friction without slippage but is compliant with shear forces occasioned by temperature changes and, by reason of its elasticity, returns the members to their initial position when the original temperature is restored. In a second form of the invention, the steel flange is grooved to form a thin ring and the ring is slotted to provide flexible fingers on which the disc rests. These fingers likewise maintain permanent contact with the disc and are likewise compliant with changes in relative position occasioned by temperature variations, restoring the disc to original position relative to the spindle.

Spindle hub-disc interface

Winchester disc drive

A latch interlock mechanism for an access door through which a magnetic disc cartridge is inserted into a disc-drive assembly. The interlock prevents the access door from being opened while a magnetic head is being loaded or is loaded onto the disc. A pivot latch cooperating with the access door is coupled to a rigid rod which moves along its length. The rod is coupled to the head lift mechanism which loads and unloads the magnetic heads. The push rod is coupled to the pivot latch by means of a coil spring co-axially mounted on the push rod with the end of the spring furthest from the first end of the push rod fixedly attached to the push rod. The other end of the coil spring interacts with the pivot latch. The second end of the push rod is coupled to an actuator element of the head lift mechanism by means of a pivoted lever. During a head load cycle, the movement of the actuator element is coupled to the push rod to engage the latch before the heads are lowered onto the surfaces of the disc. A small button located at the tip of the first end of the push rod may be pressed through an opening in the disc-drive assembly to manually unload the heads from the surface of the disc and to disengage the pivot latch from the access door.

Access door latch and interlock mechanism

An actuator for linearly moving magnetic heads in which an open-ended carriage assembly extends down both sides of the magnet structure in order to provide a much shorter actuator assembly than is typical is described. The loading mechanism is not mounted upon the carriage assembly, thereby allowing the actuator to have a higher resonant frequency than those actuators which carry a more complex structure on the carriage assembly. The magnet structure is in the shape of an E with the motor coil, which is mounted across the open end of the carriage assembly, moving along this center section of the magnet structure. Alignment pins located at the other end of the carriage assembly allow the magnetic head arms to be mounted and aligned quickly and with precision.

Linear head actuator

A mechanism for loading and unloading magnetic heads from the surfaces of a magnetic disc is described. The invention uses lift rods which are pivoted about a portion of their length and have offset sections which cooperate with the head lift arms or mounting flexures upon which the magnetic heads are mounted. The lift rods are controlled through other offset sections located along their lengths. These other offset sections, in the preferred embodiment, are pressed against conical surfaces which are oriented so that the axes of the surfaces are in a direction perpendicular to the pivoting axes of the lift rods. Movement of the conical surfaces toward and away from the pivoting axes of the lift rods imparts an arcuate motion to the offset sections of the lift rods with which they cooperate, and this correspondingly produces arcuate motions in the offset sections which cooperate with the head mounting flexures. By this motion, the magnetic heads are gently loaded or unloaded onto or from a magnetic disc. In the preferred embodiment, the motion of the conical surfaces are accurately controlled by a linear stepper motor.

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San Carlos, CA, United States of America

Harold T Wright