Abstract: 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.

Abstract: 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.

Abstract: A disk drive includes a disk that has a data side and an unread side. A first read head faces and is adjacent the data side. The disk drive also includes a cylindrical shroud wall that is substantially orthogonal to the unread side and that completely encircles the disk outer periphery. A radial spacing between the cylindrical shroud wall and the disk outer periphery nowhere exceeds 1 mm. The disk drive does not include any read head that faces and is disposed adjacent the unread side.

Abstract: A novel disk drive includes an enclosure and a disk rotatably mounted to and within the enclosure. The disk drive enclosure has a fill port opening with an internally threaded section and an internal annular seating surface. A fill port valve is disposed within the fill port opening. The fill port valve includes an externally threaded section that is engaged with the internally threaded section of the fill port opening, an external annular seating surface in contact with and forming a continuous annular seal with the internal annular seating surface of the fill port opening, and a gas flow channel spanning the externally threaded section of the fill port valve. The disk drive may be helium-filled, and may also include a metal foil seal that is externally adhered to the disk drive enclosure and covers the fill port opening and the fill port valve.

Abstract: Described herein is a disk drive having a crash stop assembly that includes a crash stop section with an outer wall extending along a first axial length of the crash stop assembly and a retaining section extending from the crash stop portion. The retaining section includes a helical portion that is elastically compressible along a second axial length, different from the first axial length, of the crash stop assembly when a base and top cover of the disk drive are coupled together.

Abstract: A C-shaped bobbin includes a bobbin base member adjacent and attached to a first lateral leg of an actuator coil. A bobbin recess, adjacent the bobbin base member, separates first and second bobbin wings. The first and second bobbin wings define first and second wing lengths measured parallel to first and second longitudinal legs of the coil, respectively, and also define first and second wing widths measured normal to the first and second longitudinal legs, respectively. The bobbin recess defines a recess depth measured normal to the first lateral leg, and defines a recess width measured parallel to the first lateral leg. Each of the first and second wing lengths is less than the length of the longitudinal legs. The recess depth is at least half a base member width. The recess width is at least twice the first wing width and/or the second wing width.

Abstract: There is provided an actuator for a disk drive. The actuator includes an actuator body defining an axis of rotation. The actuator further includes a coil. The actuator further includes a wrap-around support extending from the actuator body radially beyond the coil with respect to the axis of rotation without encircling the coil. The actuator further includes a tang supported by the wrap-around support. The coil is positioned radially between the tang and the axis of rotation. The actuator body, the wrap-around support, and the tang are all a single components comprising a metal material having material continuity rather than an assembly of subcomponents.