Western Digital Technologies, Inc.

Hgst Netherlands, B.v.

Jung-Seo Park

Manoj Keshavan

Siddhesh Vivek Sakhalkar

Thomas J Hitchner

Arman V Golgolab

Qing Dai

Sukumar Rajauria

Hiromitsu Masuda

Robert J McNab

Xiaokun L Chew

Ruihua Li

Mehdi Habibollahzadeh

Dongying Li

Shigenori Takada

Fred Golinveaux

Yixiang Zhang

A data storage device may include a container comprising a gas-permeable membrane and a temperature-sensitive gas-releasing substance inside of the container. The temperature-sensitive gas-releasing substance is characterized by a gas-release profile wherein, below a critical temperature, the temperature-sensitive gas-releasing substance releases essentially none of a particular gas, and above the critical temperature, and within a range of expected operating temperatures of the data storage device, the temperature-sensitive gas-releasing substance releases the particular gas in quantities that generally increase with increasing temperature.

Passive and active gas compensation techniques for data storage devices

A multi-actuator hard disk drive includes a lower actuator with a corresponding voice coil motor assembly (VCMA), a coaxial upper actuator with a corresponding VCMA, and a central support plate positioned between the upper and lower VCMAs and to which the upper VCMA is fastened. Use of a central support plate enables some control over the direct and coupled plant transfer functions, while effectively providing a base support structure for the upper VCMA and enabling use of conventionally-sized fasteners.

Center structure having attachment support for an actuator in a multi-actuator hard disk drive

A multi-actuator hard disk drive includes a lower actuator with a corresponding voice coil motor assembly (VCMA), a coaxial upper actuator with a corresponding VCMA, and a central extended stiffener plate positioned between the upper and lower VCMAs and extending beyond the pivot area at least to an area adjacent to the disk stack. Use of an extended stiffener plate enables some control over the direct and coupled plant transfer functions, while effectively providing a base support structure for the upper VCMA and cover support structure for the lower VCMA.

Extended center stiffener plate for improved structural dynamics of actuators in a multi-actuator hard disk drive

A multi-actuator hard disk drive includes a lower actuator with a corresponding voice coil motor assembly (VCMA) including a magnet coupled with a first magnet housing plate, a coaxial upper actuator with a corresponding VCMA including a magnet coupled with a second magnet housing plate, and a central support plate mechanically fastened to an enclosure base, at one or more locations, and positioned between the first magnet housing plate of the first VCMA and the second magnet housing plate of the second VCMA. Thereby, the pivot and VCM tilt and the coil torsion modes of the direct plant transfer function are minimized and the peak-to-peak gain in the coil torsion mode of the coupled plant transfer function is reduced.

Anchoring structure for improved structural dynamics of actuators in a multi-actuator hard disk drive

A multi-actuator data storage device such as a hard disk drive may include a lower actuator-pivot-VCM assembly including a lower pivot shaft and a lower motor assembly, an upper actuator-pivot-VCM assembly including an upper pivot shaft and an upper motor assembly, and a central support structure or plate sandwiched between the lower and upper pivot shafts and the lower and upper motor assemblies. The central support structure may be shaped to make contact with the motor assemblies only at discrete assembly locations and to make contact with the pivot shafts at opposing raised pads. Viscoelastic dampers may be adhered to the central support structure at the contact locations to dampen motor vibrational modes and/or to reduce the amplitude of vibration transmitted among the actuator-pivot assemblies. Such an assembly may increase the tilt and in-phase butterfly mode frequencies and decrease the gains of the tilt and coil torsion modes.

Central support for improved structural dynamics of actuators in a multi-actuator hard disk drive

An actuator pivot shaft assembly for a multi-actuator data storage device may include one or more annular grooves extending radially inward from an outer surface of the pivot shaft, thereby desirably weakening or structurally decoupling the shaft between the actuators, to assist with inhibiting transmission of vibration between the actuators during operation. The shaft assembly may further include an elastomeric damper positioned within the annular groove(s), to damp transmission of vibrational forces between the actuators through the shared shaft.

Reducing vibration transmission in a dual actuator disk drive utilizing a single pivot shaft

A split-shaft pivot assembly for a dual-actuator data storage device may include a first pivot shaft around which a first bearing assembly is affixed, a second pivot shaft around which a second bearing assembly is affixed, and whereby the two pivot shafts are coupled together by way of an interface spacer between the shafts. The interface spacer may include a receiving structure at each end of a housing, for receiving an end of a respective shaft, and an annular slot circumscribing the housing between the receiving structures, where an elastomeric damper is positioned within the slot. The interface spacer housing may be composed of a material having a lower elastic modulus than the material of which the shafts are composed, thereby making the interface spacer relatively compliant. Such features may serve to inhibit and/or damp transmission of vibrational energy among the actuators through the shared split-shaft.

Split-shaft pivot with interface spacer for a dual-actuator hard disk drive

A split-shaft pivot assembly for a dual-actuator data storage device may include a first pivot shaft having a threaded stud extending from one end and an attachment flange at the other end, and a second pivot shaft having a threaded bore at one end a structurally equivalent attachment flange at the other end, where the two pivot shafts are attached to each other by threading the stud into the bore. A first bearing assembly may be affixed with a first preload around the first pivot shaft, and a second bearing assembly may be affixed with a second different preload around the second pivot shaft. The pivot assembly may further include an elastomeric damper positioned within an annular groove formed in, and around the threaded stud of, the first pivot shaft. Such features may serve to inhibit and/or damp transmission of vibrational energy among the actuators through the shared split-shaft.

Split-shaft pivot for a dual-actuator hard disk drive

A contamination mitigation cap for a hard disk drive actuator pivot assembly is affixed to the rotatable carriage of an actuator assembly and, in conjunction with a bearing hub cap, forms a labyrinth seal for retaining pivot bearing contamination. Consequently, the risk of such contamination migrating to the head-disk interface and causing read/write problems is mitigated, especially in the context of sleeveless pivot bearing assemblies. Various shapes of the contamination mitigation cap may be utilized, such as a flat ring, an S-section ring, and an L-section ring.

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San Jose, CA, United States of America

Jung-Seo Park