Western Digital Technologies, Inc.

Seagate Technology Incorporated

Diep Nguyen

David K Myers

Bikash Sukla

Klaus Diete Kloeppel

Ronald G Ilagan

Hamid Salehizadeh

Michael L Mallary

Gerardo Bertero

Jifang Tian

Donald Joseph Brunnett

Hongqi Li

Allyson Ly

An approach to a reduced-head hard disk drive (HDD) involves an actuator elevator subsystem that includes a ball screw cam assembly with an axial flux permanent magnet (AFPM) motor affixed to a cam screw to drive rotation of the screw, which drives translation of an actuator arm assembly so that a corresponding pair of read-write heads can access different magnetic-recording disks of a multiple-disk stack.

Axial flux permanent magnet motor for ball screw cam elevator mechanism for reduced-head hard disk drive

An approach to a reduced-head hard disk drive (HDD) involves an actuator elevator subsystem that includes a ball screw cam assembly with a hybrid permanent magnet (PM)-variable reluctance (VR) stepper motor disposed therein, to rotate the cam screw, which vertically translates an actuator arm assembly so that a corresponding pair of read-write heads can access different magnetic-recording disks of a multiple-disk stack. A suitably configured hybrid stepper motor can provide 200 full steps/rev for a 3.8 mm translation. Thus, to meet or surpass a step resolution of 6 &#x3bc;m/&#x3bc;step or 0.5625&#xb0;/&#x3bc;step, the hybrid stepper motor would only need to be operated at 4 micro-step mode in order to achieve a 0.45&#xb0;/&#x3bc;step or 0.00475 mm/&#x3bc;step, which enables a smoother motion since the available holding torque at the 4micro-step provides sufficient torque margin to overcome load torque, frictional torque, and detent torque.

In-pivot hybrid stepper motor for ball screw cam elevator mechanism for reduced-head hard disk drive

An approach to a reduced-head hard disk drive (HDD) involves an actuator subsystem that includes a ball screw cam assembly wherein the number of starts of a multi-start screw equals the number of balls riding in a corresponding start. A stepper motor may be disposed within the screw, to drive rotation of the screw, which drives translation of an actuator arm assembly so that a corresponding pair of read-write heads can access different magnetic-recording disks of a multiple-disk stack. The actuator subsystem may further include a cam locking mechanism for coupling and decoupling the actuator arm with a coil support structure and corresponding voice coil, so that the cam mechanism is able to move under the control of a voice coil motor when input/output operations are performed and is able to move the actuator arm assembly during translation operations.

Low-profile ball screw cam elevator mechanism for cold storage data storage device

In-pivot stepper motor for ball screw cam elevator mechanism for cold storage data storage device

Pillow case

A method to fabricate a fluid bearing spindle includes creating a hollow cylindrical bore through a solid workpiece. The hollow cylindrical bore has a journal bearing portion including first and second distal tapered bearing segments separated by a central bearing segment having a constant radius. Each of the first and second distal tapered bearing segments has a tapered bearing radius that increases with distance from the central bearing segment to a maximum tapered bearing radius that is in the range of 0.5 microns to 1.5 microns greater than the constant radius. Subsequently, a cylindrical spindle shaft is inserted into the hollow cylindrical bore. In an alternative embodiment, a cylindrical outer surface of the spindle shaft includes the tapered bearing segments, rather than the hollow cylindrical bore.

Disk drive spindle with fluid journal bearing having increased radial clearance in axial end regions

A rotary spindle has a rotatable shaft that defines a shaft axis of rotation, and has a shaft top land that is normal to the shaft axis of rotation. A disk mounting hub has an outer disk mounting surface, and has an inner cylindrical bore with an inner cylindrical surface that faces and is in radial compression with an outer cylindrical surface of the shaft at a cylindrical hub-to-shaft interface. The cylindrical hub-to-shaft interface is substantially concentric about the shaft axis of rotation. A disk clamp is fastened to the rotatable shaft, and the disk clamp has a clamp bottom land that faces and is in contact with the shaft top land.

Rotary spindle having a disk clamp bottom land facing and in contact with a shaft top land

A disk drive includes a disk drive base comprising a first metal material. The disk drive base may include a first opening and a first attachment feature to which a head actuator assembly pivot may be attached. A motor support may be embedded in the first opening in the disk drive base. The motor support consists of a second metal material having a damping coefficient higher than that of the first metal material. A rotary spindle may be attached to the motor support, and a disk may be attached to the rotary spindle.

Method for fabricating a disk drive base for a disk drive

A system is provided that increases the spindle stiffness of a disk drive while optimizing power consumption. A multipurpose bearing provides axial stiffness and enhanced stiffness against radial and pitch loads applied to the spindle. When used in combination with a journal bearing, conventional thrust bearings may be eliminated without sacrificing overall stiffness. As a result, the height of the disk drive may be reduced, thereby making the system desirable to be used in smaller electronic devices.

Method of making a fluid bearing

A disk drive to load a head to a load/unload (LUL) zone of a disk is disclosed. The disk drive comprises an actuator including a head; a disk having a plurality of tracks; and a processor to control the movement of the actuator and the head relative to the disk. The processor may further: measure a back electromagnetic force (BEMF) of a spindle stator of a spindle motor after turning off the spindle motor; identify a modulation feature of the BEMF that indicates an identifiable circumferential position; command the storage the modulation feature of the BEMF; and control loading the head onto the LUL zone of the disk when the modulation feature is matched.

Growing community of inventors

Castro Valley, CA, United States of America

Diep Nguyen