Acoustic source with piezoelectric actuator array and stroke amplification for broad frequency range acoustic output

摘要

An acoustic energy source that amplifies the stroke of electrically reactive elements having a body with an elastomer filled first cavity, a highly incompressible fluid filling a second cavity, and bores intersecting the second cavity that extend radially outward from second cavity. Quill assemblies in the bores each include an electrically reactive element and a tip projecting radially into the second cavity. A dynamic yoke having a lower portion projecting into the second cavity, and a pressure disk projects into the first cavity. A diaphragm on the body and on a side of the dynamic yoke opposite its lower portion. A fluid forms a film between the dynamic yoke, static yoke and quill tips. Applying alternating electricity reciprocates the tips into and out of the second cavity; reciprocates the dynamic yoke and diaphragm to generate the acoustic energy.

主权项

1. An acoustic energy source for use with a downhole tool comprising:
a body mounted to a housing of the downhole tool; a first cavity in the body having an elastomer; a second cavity in the body having a fluid; a diaphragm coupled with the body adjacent the first cavity, and that selectively reciprocates axially outward from the first cavity and axially inward to the first cavity; a dynamic yoke having an end projecting into the second cavity and an opposite end holding a pressure disk projecting into the first cavity and embedded in the elastomer of the first cavity; a plurality of electrically reactive stacks that are each selectively energized into an oscillatory extended and contracted configuration; a plurality of quill tips each having an end in contact with a one of the electrically reactive stacks and each is moved radially inward when an associated electrically reactive stack is in the extended configuration, and each is moved radially outward when an associated electrically reactive stack is in the contracted configuration, and each quill tip having an opposite end profiled substantially complimentary with a recesses in the dynamic yoke, so that a film of the fluid in the second cavity remains between each quill tip and the dynamic yoke when the electrically reactive stacks are in the extended configuration and in the contracted configuration; and a tuned resonant mount having an end attached to the body and an opposite end attached to the downhole tool, and that couples dynamically with motion of the diaphragm to create resonant response of the acoustic output of the source at designated operational frequencies and ranges.