초록 ▼

A limp propeller for underwater use with a high mechanical damping ability to absorb so-called broadband vibration noise is comprised of a fabric-like material, preferably made of braided high tensile strength material such as fiberglass or graphite fibers. The fabric is devoid of any stiffening pla

A limp propeller for underwater use with a high mechanical damping ability to absorb so-called broadband vibration noise is comprised of a fabric-like material, preferably made of braided high tensile strength material such as fiberglass or graphite fibers. The fabric is devoid of any stiffening plastic or epoxy matrix material. Rather a flexible matrix material having relatively large hysteretic losses when deformed o cyclically in place of the stiffening plastic or epoxy matrix, or no matrix material at all is used in the present invention. The flexible matrix material or the complete absence of any matrix material renders the propeller blade relatively limp to flexure, thereby reducing its acoustic radiation damping or radiation efficiency.

대표청구항 ▼

A limp propeller comprising: a central hub having an axis of rotation and adapted for mounting to a rotatable shaft; a circular support ring; and a plurality of circumferentially spaced apart propeller blades extending radially from said central hub, each of said propeller blades having one end conn

A limp propeller comprising: a central hub having an axis of rotation and adapted for mounting to a rotatable shaft; a circular support ring; and a plurality of circumferentially spaced apart propeller blades extending radially from said central hub, each of said propeller blades having one end connected to said central hub and a tip thereof connected to said circular support ring, and each of said propeller blades comprising: a leading edge and a trailing edge each of which extends substantially radially from said hub to said tip of said blades, and a first face and a second face each of which extends between said leading and trailing edges; a flexible fabric of high tensile strength material, said fabric forming said leading and trailing edges and said first and second faces; first and second support spars extending radially between said hub and said circular support ring, said first space being circumferentially spaced apart from said second spar, whereby said flexible fabric surrounds said first and second spars; and at least one flat inner support spaced radially from said hub and extending between said first and second spars and attached thereto, whereby said flexible fabric wraps peripherally around said at least one inner support.