Dynamic magnetic information storage or retrieval – Record transport with head stationary during transducing – Disk record
Reexamination Certificate
2001-08-09
2003-08-05
Heinz, A. J. (Department: 2653)
Dynamic magnetic information storage or retrieval
Record transport with head stationary during transducing
Disk record
Reexamination Certificate
active
06603633
ABSTRACT:
FIELD OF THE INVENTION
The claimed invention relates generally to disc drive data storage devices and more particularly to a damper for damping acoustic noise generated by a disc drive.
BACKGROUND OF THE INVENTION
Disc drives are commonly used for many computer environments to store large amounts of data in a form readily available to a user. Typically, a disc drive has one or more magnetic discs rotated by a spindle motor at a constant high speed. Each disc has a data storage surface divided into a series of concentric data tracks radially spaced across a band having an inner diameter and an outer diameter. The data is stored within the data tracks in the form of magnetic flux transitions. These flux transitions are induced by one or more read/write heads.
Each read/write head includes an interactive element such as a magnetic transducer. The transducer senses the magnetic transitions on a selected data track to either write data to the data track or to read the data stored on the data track. Each of the read/write heads is mounted to a rotary actuator arm and is positioned by the actuator arm over a selected data track to either write data to the data track or to read the data stored on the data track. Each read/write head includes a slider assembly having an air bearing surface that, in response to air currents generated by rotation of the disc, causes the head to fly over the disc. A desired gap separates the read/write head and the corresponding disc.
In a typical application, multiple open-center discs and spacer rings are alternately stacked on a spindle motor hub. The hub that defines a core of the stack also serves to align the discs and the spacer rings about a common axis. The discs, the spacer rings and the spindle motor hub collectively define a disc pack assembly. The read/write heads, which mount on a complementary stack of actuator arms to form part of an actuator assembly, access the surfaces of the stacked discs. The actuator assembly includes features to conduct electrical signals from the read/write heads to a flex circuit, which in turn conducts the electrical signals to a flex circuit connector mounted to a base deck of the disc drive.
When the disc drive is not in use, the read/write heads are parked in a position separate from the data storage surfaces of the discs. A landing zone is typically provided on each of the disc surfaces where the read/write heads are positioned before the rotational velocity of the spinning discs decreases below a threshold velocity necessary to sustain the air bearing. The landing zones are usually located near the inner diameter of the discs.
The actuator assembly typically has an actuator body that pivots about a pivot assembly that is disposed in a medial position of the actuator assembly. A voice coil motor positions a proximal end of the actuator assembly. This positioning of the proximal end of the actuator assembly causes a distal end of the actuator assembly, which supports the read/write heads, to move across the face of the discs.
The coil of the voice coil motor conducts an electrical current. This electrical current through the coil generates an electrical field. The coil is positioned in a magnetic field between an upper pole and a lower pole of the voice coil motor. The electrical filed of the coil interacts with the magnetic generated by the upper pole and the lower pole to cause the actuator assembly to pivot about the pivot assembly.
The pivotal movement of the actuator assembly generates reactionary forces in the stationary magnetic upper pole and lower pole causing the upper pole and the lower pole to vibrate. Because the upper pole and the lower pole are attached to the base deck, the vibration of the upper pole and the lower pole is transmitted throughout the disc drive and, in particular to the top cover. The vibration of the top cover causes the top cover to generate acoustic noise to the surrounding environment.
There have been many attempts to address the problem of undesirable vibration of the voice coil motor. For example, U.S. Pat. No. 5,999,374 issued to Kim (Kim '374) discloses the use of three elastic screw-shaped dampers inserted into bores in an upper yoke (upper pole) to damp vibration. A top of the three elastic dampers tightly presses against an inner surface of a top cover to restrain the motion of the top cover.
U.S. Pat. No. 6,175,469 issued to Ahmad et al. (Ahmad '469) discloses the use of an elastomeric member joined to a magnetically permeable liner to form a dampening member. The dampening member is attached to a top cover of the disc drive and compressed between the top cover and an upper pole of the voice coil motor.
While both the dampers of Kim '374 and the dampening member of Ahmad '469 have been found operable in reducing vibration of the top cover, there remains a need for a device that more effectively reduces acoustic noise generated by the top cover by dissipating the vibrational energy that is generated by the voice coil motor and transmitted to the top cover.
SUMMARY OF THE INVENTION
In accordance with preferred embodiments, a beam damper for a voice coil motor (VCM) of a disc drive is provided to reduce acoustic noise generated by the disc drive. The beam damper reduces the acoustic noise by dissipating vibrational energy of the disc drive.
The disc drive has a top cover and a VCM with a magnetic upper pole. The VCM induces vibrational energy in the disc drive by forces exerted on the upper pole and a lower pole in reaction to electromotive forces that the VCM generates to pivotally move an actuator assembly. The beam damper is affixed to a top cover of the disc drive and supported over the upper pole. The beam damper includes a substantially flat platform, and a series of flex beams extending from the platform and engaging the upper pole to resiliently bias the top cover away from the upper pole.
These and various other features and advantages that characterize the claimed invention will be apparent upon reading of the following detailed description and review of the associated drawings.
REFERENCES:
patent: 5214549 (1993-05-01), Baker et al.
patent: 5430589 (1995-07-01), Moir et al.
patent: 5483397 (1996-01-01), Gifford et al.
patent: 5517375 (1996-05-01), Dion et al.
patent: 5825585 (1998-10-01), Hatam-Tabrizi
patent: 5914836 (1999-06-01), Pottebaum
patent: 5999374 (1999-12-01), Kim
patent: 6002546 (1999-12-01), Yagi et al.
patent: 6175469 (2001-01-01), Ahmad et al.
patent: 6288866 (2001-09-01), Butler
patent: 0 874 175 (1998-10-01), None
patent: 2336238 (1999-10-01), None
Heaton Daniel M.
Stricklin John D.
Trammell Curtis A.
Treleven Gary A.
Wood Roy L.
Fellers , Snider, et al.
Heinz A. J.
Seagate Technology LLC
LandOfFree
Parallel spring design for acoustic damping of a disc drive does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Parallel spring design for acoustic damping of a disc drive, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Parallel spring design for acoustic damping of a disc drive will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3123171