Browse Prior Art Database

Stacked, symmetrical, flexure pivot bearing

IP.com Disclosure Number: IPCOM000014021D
Original Publication Date: 2000-Aug-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Abstract

This invention reveals a new pivot design that relies on flexures to provide rotational motion. Three of these flexure bearings are stacked to provide sufficient rotation range of motion for use in a hard disk drive actuator. Each flexure bearing is a one piece design. The design is symmetrical along three orthogonal axes to prevent the creation of actuator resonances arising from any asymmetric boundary condition.

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Stacked, symmetrical, flexure pivot bearing

   This invention reveals a new pivot design that relies on flexures to provide
rotational motion. Three of these flexure bearings are stacked to provide
sufficient rotation range of motion for use in a hard disk drive actuator. Each
flexure bearing is a one piece design. The design is symmetrical along three
orthogonal axes to prevent the creation of actuator resonances arising from any
asymmetric boundary condition.

The rotary flexure is a monolithic device, machined from a solid metal rod. It is
designed for high radial and axial stiffnesses, low rotational stiffness and a
long fatigue life. The quad-foil rotary flexure has four radial, equally spaced
thin plates that extend from and sleeve to the inner quad-lobed support, see
figure. By minimizing the distance from the inner terminus of the flexures to
the rotational axis the torsional stiffness is made as small as possible. The
plates can be notched to increase torsional flexibility. A constrained layer
damping material may be placed on the plate's surface to dampen vibrations. The
device flexes to provide rotation about a single axis through a range of +/-12
degrees. The four lobes of the inner support are joined at the rotation axis to
provide an extremely rigid attachment for the flexure elements, thus allowing
high radial and axial stiffnesses. To reduce the concentration of stresses,
generous fillet radii were incorporated at the inner and outer ends of the fins.
The quad-lobed su...