Surface effects vehicle having variable geometry lift fan

Claim 2

A surface effects vehicle comprising: a body having means defining an open-bottom plenum adapted to be substantially closed when the body is disposed on a surface; an actuatable, centrifugal type lift fan carried by the body and having a fluid passage adapted to direct air under pressure into said plenum to form an air cushion to support the same above said surface and to permit movement of the body over the surface; means coupled with said lift fan and movable across said fluid passage for causing a change in the volume rate of flow of air therethrough when the lift fan is actuated; and means coupled with said lift fan for actuating the same.

Claim 3

A vehicle as set forth in claim 1, wherein said plenum forming means includes a pair of spaced, buoyant sides, a front skirt, and a rear skirt spaced from the front skirt, said skirts spanning the distance between said sides.

Claim 4

A vehicle as set forth in claim 1, wherein is provided a propulsion unit mounted on said body for moving the latter over said surface.

Claim 5

A vehicle as set forth in claim 1, wherein said lift fan has a fluid passage therethrough, said causing means including structure movable relative to said lift fan and across said passage to change the effective cross section thereof, and actuatable means coupled with said structure for moving the same relative to said lift fan.

Claim 6

A vehicle as set forth in claim 4, wherein said structure includes a cylindrical sleeve.

Claim 7

A vehicle as set forth in claim 4, wherein said structure includes a pair of concentric sleeves.

Claim 8

A vehicle as set forth in claim 4, wherein said lift fan has a rotor, said structure including a sleeve movable axially of the rotor.

Claim 9

A vehicle as set forth in claim 7, wherein said rotor has a plurality of spaced blades thereon, there being an air inlet for the lift fan adjacent to the axis of the rotor, said structure including a sleeve movable axially of the rotor to vary the effective widths of the rotor blade.

Claim 10

A vehicle as set forth in claim 8, wherein each rotor blade has a radially innermost end and a radially outermost end, the sleeve being movable into operative positions adjacent to the radially outermost ends of the rotor blades.

Claim 11

A vehicle as set forth in claim 1, wherein said lift fan has a rotor provided with a pair of opposed sides and a plurality of spaced blades on each side thereof, respectively, said lift fan having a pair of air inlets on respective sides of the rotor, said causing means including a sleeve for each air inlet, respectively, the sleeves being movable axially of said rotor and disposed to vary the widths of respective blades, whereby the effective cross-section of the fluid passage through the fan is changed to thereby cause a change in the volume rate of flow of air through the lift fan.

Claim 12

A vehicle as set forth in claim 1, wherein said body has a deck, said lift fan being disposed on the deck and having an air outlet communicating with said plenum through the deck.

Claim 13

A vehicle as set forth in claim 1, wherein is provided means coupled with said causing means for actuating the same As a function of the vertical acceleration of said body at a predetermined location thereon relative to said surface.

Claim 14

A surface effects vehicle as set forth in claim 1, wherein said actuating means comprises a gas turbine engine.

Claim 15

A surface effects vehicle as set forth in claim 1, wherein said body comprises a surface effects ship movable over the water and having a weight of at least 2,000 tons.

Claim 16

A surface effects ship comprising: a buoyant hull having a deck, a pair of spaced sides, a front skirt, and a rear skirt, the deck, the sides and the skirts defining a closed air-receiving plenum when the hull is on a body of water; a lift fan carried by the deck and having a pair of air inlets, an air outlet spaced from said air inlets, and a fluid passage extending between the air inlets and the air outlet, said air outlet being in fluid communication with said plenum, said lift fan having a rotor, the axis of the rotor passing through the air inlets, said rotor having a pair of opposed sides and a plurality of spaced blades on each side thereof, respectively; a sleeve for each side of the rotor, respectively, the sleeves surrounding respective air inlets and being movable axially of the rotor to thereby vary the effective widths of respective blades, whereby the effective cross section of said fluid passage is changed to cause a change in the volume rate of flow of air therethrough; means coupled with said hull for sensing the movement of a predetermined location thereon as the hull moves relative to a surface; means coupled with the sleeves for moving the same as a function of the sensing of said hull movement; and means coupled with the rotor for rotating the same in a direction to cause a flow of air through said fluid passage and into said plenum to form an air cushion for supporting said hull on the water.

Claim 17

A surface effects ship comprising: a buoyant hull having a deck, a pair of spaced sides, a front skirt, and a rear skirt, the deck, the sides and the skirts defining a closed air-receiving plenum when the hull is on a body of water; a lift fan carried by the deck and having a pair of air inlets, an air outlet spaced from said air inlets, and a fluid passage extending between the air inlets and the air outlet, said air outlet being in fluid communication with said plenum, said lift fan having a rotor, the axis of the rotor passing through the air inlets, said rotor having a pair of opposed sides and a plurality of spaced blades on each side thereof, respectively; a sleeve for each side of the rotor, respectively, the sleeves surrounding respective air inlets and being movable axially of the rotor to thereby vary the effective widths of respective blades, whereby the effective cross section of said fluid passage is changed to cause a change in the volume rate of flow of air therethrough; means coupled with said hull for sensing the movement of a predetermined location thereon as the hull moves relative to a surface; means coupled with the sleeves for moving the same as a function of the sensing of said hull movement; and means coupled with the rotor for rotating the same in a direction to cause a flow of air through said fluid passage and into said plenum to form an air cushion for supporting said hull on the water.

Claim 20

A method as set forth in claim 16, wherein said varying step includes sensing said acceleration, developing an error signal in response to the sensing step, and changing said volume rate of flow as a function of said error signal.

Claim 21

A method as set forth in claim 16, wherein said path has a circular portion, said changing step including blocking an annular part of said path portion.

Claim 22

A surface effects vehicle comprising: a body having means defining an open-bottom plenum adapted to be substantially closed when the body is disposed on a surface; an actuatable lift fan carried by the body and adapted to direct air under pressure into said plenum to form an air cushion to support the same above said surface and to permit movement of the body over the surface; means coupled with said lift fan for causing a change in the volume rate of flow of air therethrough when the lift fan is actuated; means coupled with said lift fan for actuating the same; and actuatable reciprocatory actuating device responsive to an error signal; and means responsive to the vertical acceleration of a predetermined location of said body and coupled with said actuating device for generating an error signal representative of the magnitude of said acceleration with respect to a predetermined reference.

Claim 23

A surface effects vehicle comprising: a body having means defining an open-bottom plenum adapted to be substantially closed when the body is disposed on a surface; an actuatable lift fan carried by the body and adapted to direct air under pressure into said plenum to form an air cushion to support the same above said surface and to permit movement of the body over the surface; means coupled with said lift fan for causing a change in the volume rate of flow of air therethrough when the lift fan is actuated; means coupled with said lift fan for actuating the same; and actuatable reciprocatory actuating device responsive to an error signal; and means responsive to the vertical acceleration of a predetermined location of said body and coupled with said actuating device for generating an error signal representative of the magnitude of said acceleration with respect to a predetermined reference.