G11B19/2009

ENERGY RECOVERY FROM A SPINDLE MOTOR USING A SEQUENCE OF A BRAKING PHASE, AN ACTIVE STEP-UP PHASE AND AN ACTIVE BRAKING PHASE IN RESPONSE TO EXTERNAL POWER SUPPLY FAILURE

The half-bridges driving a multiphase motor are controlled to perform a sequence of operations to support charging a hold capacitor. First, in a brake configuration, the half-bridge transistors are controlled such that either high-side transistors or low-side transistors of the half-bridges are turned on. Second, in an active step-up configuration, the half-bridge transistors are controlled such that the high-side transistor of a first half-bridge and the low-side transistor of a second half-bridge are both turned on and the low-side transistor of the first half-bridge and the high-side transistor of the second half-bridge are both turned off. Third, in an active brake configuration, the half-bridge transistors are controlled such that the low-side transistor of the first half-bridge and the high-side transistor of the second half-bridge are both turned on and the high-side transistor of the first half-bridge and the low-side transistor of the second half-bridge stage are both turned off.

Method for fabricating a magnetic tunneling junction (MTJ) structure

A method for fabricating an improved magnetic tunneling junction (MTJ) structure is described. A bottom electrode is provided on a substrate. A MTJ stack is deposited on the bottom electrode. A top electrode is deposited on the MTJ stack. A first stress modulating layer is deposited between the bottom electrode and the MTJ stack, or a second stress modulating layer is deposited between the MTJ stack and the top electrode, or both a first stress modulating layer is deposited between the bottom electrode and the MTJ stack and a second stress modulating layer is deposited between the MTJ stack and the top electrode. The top electrode and MTJ stack are patterned and etched to form a MTJ device. The stress modulating layers reduce crystal growth defects and interfacial defects during annealing and improve the interface lattice epitaxy. This will improve device performance.

METHOD FOR FABRICATING A MAGNETIC TUNNELING JUNCTION (MTJ) STRUCTURE
20190341542 · 2019-11-07 ·

A method for fabricating an improved magnetic tunneling junction (MTJ) structure is described. A bottom electrode is provided on a substrate. A MTJ stack is deposited on the bottom electrode. A top electrode is deposited on the MTJ stack. A first stress modulating layer is deposited between the bottom electrode and the MTJ stack, or a second stress modulating layer is deposited between the MTJ stack and the top electrode, or both a first stress modulating layer is deposited between the bottom electrode and the MTJ stack and a second stress modulating layer is deposited between the MTJ stack and the top electrode. The top electrode and MTJ stack are patterned and etched to form a MTJ device. The stress modulating layers reduce crystal growth defects and interfacial defects during annealing and improve the interface lattice epitaxy. This will improve device performance.

Spindle motor with particular rotor magnet and stator teeth dimensions and disk drive device including the same

A spindle motor includes a stationary unit and a rotating unit. The rotating unit is rotatable with respect to the stationary unit in a state in which the stationary unit is aligned with a central axis. The stationary unit includes a stator core and coils. The stator core includes a cylindrical core back and teeth units extending radially outward from an outer circumferential portion of the core back. The coils are defined by a conductive wire wound around each of the teeth units. The rotating unit includes a magnet located radially outside the teeth units. An axial length of the magnet is shorter than an axial length of the teeth unit. A first angle corresponding to a circumferential width of the teeth unit is smaller than a second angle corresponding to a circumferential gap between the adjacent teeth units.

Disk clamping mechanism including annular ring member

A disk drive assembly including a spindle motor including a hub and a central axis, at least one disk disk having a central opening positioned on the hub and concentric about the central axis, an annular ring member concentric about the central axis, wherein a first portion of the annular ring member is in contact with an outer surface of a top disk of the disk stack, and a disk clamp ring screw adjacent to and in contact with a second portion of the annular ring member, wherein the disk clamp ring screw provides a clamping force to at least partially compress the annular ring member toward the top disk of the disk stack.

GRAMOPHONE WITH A TURNTABLE, LEVITATING ON A MAGNETIC CUSHION
20190325901 · 2019-10-24 ·

The design of the gramophone (100) for playing music recordings on vinyl records (50) which rotate on a levitating turntable (10) with the help of magnetic forces, substitutes all established versions of analogue gramophones, where the drive and rotation of the turntable are predominantly provided by an electric motor and mechanical elements. The technology of the turntable (10), rotating and levitating on magnetic forces, does not require changing the other elements of the analogue gramophone device, however, its advantage is that it reduces the unwanted vibrations of the turntable (10) and its unsteady rotation while playing music. In this way the accuracy and credibility of the sound readings is improved. Additionally, the need to push the turntable stylus (32) more strongly on the vinyl record (50) is reduced, otherwise required due to the possible skipping of the stylus (32). Thus the format of the sound recording in the groove of the vinyl record (50) is maintained for a longer period of time, as well as the sharpness of the turntable stylus (32). To ensure steady rotation, the excess inertia mass of the turntable (10) is no longer required. In addition to the benefits in sound processing, the new technology also upgrades the level of the visual experience when listening to audio artistic creations. The system of the levitating and rotating turntable can also be used for other purposes, such as to display products in showroom windows and similar.

ATTENUATING REACTION FORCES CAUSED BY INTERNALLY SUPPORTED STATORS IN BRUSHLESS DC MOTORS
20190311739 · 2019-10-10 ·

An apparatus, according to one embodiment, includes: a support plate, a stator, and a stator support arm. The stator support arm has a first end that is coupled to the support plate, and extends from the support plate to the stator. Moreover, the stator is coplanar with the support plate. The apparatus further includes at least one isolation mount, and a rotor sub-assembly. The isolation mount is coupled between a second end of the stator support arm and the stator for reducing transfer of vibration from the stator to the stator support arm. The rotor sub-assembly includes a magnet, and a hub rotatably fixed relative to the magnet. Furthermore, the rotor sub-assembly is configured to rotate relative to the support plate and the stator. Other systems, methods, and computer program products are described in additional embodiments.

ATTENUATING REACTION FORCES CAUSED BY EXTERNALLY SUPPORTED STATORS IN BRUSHLESS DC MOTORS
20190311738 · 2019-10-10 ·

An apparatus, according to one embodiment, includes: a support plate, a stator, a rotor sub-assembly, and at least one isolation mount coupled between the support plate and the stator. The isolation mount is for reducing transfer of vibration from the stator to the support plate. Moreover, the stator is coplanar with the support plate. The rotor sub-assembly includes a magnet, and a hub rotatably fixed relative to the magnet. The rotor sub-assembly is also configured to rotate relative to the support plate and the stator. Other systems, methods, and computer program products are described in additional embodiments.

SPINDLE MOTOR
20190304503 · 2019-10-03 ·

A spindle motor is provided, the motor comprising: a base plate, a PCB on the base plate, a bearing assembly arranged on the base plate, a stator coupled to a periphery of the bearing assembly, a rotor rotationally coupled to the bearing assembly, the rotor including a yoke and a magnet, and a rotation shaft rotationally coupled to the bearing assembly. The base plate includes a planar portion and a protruding portion arranged along with a periphery of the yoke, the protruding portion being apart from the yoke. The base plate is partially covered with the PCB in a region where the stator is arranged. And, a height from the planar portion to an upper surface of the protruding portion is smaller than a height from the planar portion to a lower surface of the periphery of the yoke.

MOVEABLE MOTOR AND COVER FOR MOBILE DRIVE UNIT TURNTABLE
20190295591 · 2019-09-26 ·

A mobile drive unit includes a turntable and a turntable motor that is located outside of the footprint of the turntable. The motor moves up and down with the turntable such that a motor cover moves up and down with the turntable.