Vibration control system

Claim 2

In a rotary wing aircraft, a vibration control system comprising a force-producing mechanism for substantially balancing out vibrations in one direction on the aircraft caused primarily by the rotating wing means, said mechanism including a first pair of weight means, a second pair of weight means, first asynchronous motor means for rotating one said weight means from each said pair in opposite directions at an average rotational angular velocity substantially equal to a constant ratio of the angular velocity of the rotating wing means, second asynchronous motor means for rotating the other said weight means from each said pair in opposite directions at an average rotational angular velocity substantially equal to a constant ratio of the angular velocity of the rotating wing means, a source of electrical power, and means for coupling and decoupling said source to each said first and second motor means thereby controlling the speed of each said asynchronous motor means to maintain said weights at said average rotational velocity.

Claim 3

In the rotary wing aircraft as defined in claim 1 wherein said first and second asynchronous motor means each include a pair of induction motors respectively rotating one of said means.

Claim 4

In the rotary wing aircraft as defined in claim 1 further comprising sensing means responsive to a change in amplitude or phase of the vibrations in the one direction caused by the rotating wing means, said sensing means controlling said means for coupling and decoupling of said source to said first and second asynchronous motor means thereby altering the speed of at least one said motor means which alters the angular position of said weight means.

Claim 5

In the rotary wing aircraft as defined in claim 1 further comprising means for sensing the vibrations on the aircraft in the one direction and producing an output vibration signal in response thereto, means for sensing the angular position of each said pairs of weight means and producing respective weight signals in response thereto, said means for coupling and decoupling including gating means between said source and respective said motor means responsive to respective said weight signals from said first and second pairs of weight means and said output vibration signal for coupling and decoupling respective said motor means to said source.

Claim 6

In the rotary wing aircraft as defined in claim 1 further comprising a standard means for producing a reference output signal; said means for coupling and decoupling including: a pair of sensing means for sensing the speed of respective said motor means and to produce signals responsive thereto; A pair of means each receiving said reference output signal and respective said motor signal from said pair of sensing means and producing a control signal; and a pair of gating means connected between said power supply and respective said motor means, each said gating means being responsive to respective said control signal to decouple said power supply from respective said motor means when said control signal includes a pulse of one characteristic and to couple said power supply to respective said motor means in response to said control signal when said control signal includes a pulse of another characteristic.

Claim 7

In the rotary wing aircraft as defined in claim 1 further comprising a speed reference generator for producing reference pulses having a first polarity and a given repetition rate, said means for coupling and decoupling including: a pair of sensing means for sensing the speed of respective said motor means and to produce motor pulses having a polarity opposite to said first polarity and a repetition rate which is a predetermined function of the speed of each said motor means; a pair of reversible register means each receiving said reference pulses and respective said motor pulses from said pair of sensing means, each said register means providing an output signal of a first characteristic when the number of said reference pulses exceeds the number of said motor pulses and of a second characteristic when the number of said motor pulses exceeds the number of said reference pulses; and a pair of gating means connected between said power supply and respective said motor means, each said gating means being responsive to said output signal from respective said register means of one said characteristic to decouple said power supply from respective said motor means and to couple said power supply to respective said motor means in response to said output signal from respective said register means of the other said characteristic.

Claim 8

In the rotary wing aircraft as defined in claim 6 wherein each said pair of reversible register means includes a plurality of serially connected tunnel diodes.

Claim 9

In the rotary wing aircraft as defined in claim 6 wherein each said reversible register means includes a plurality of serially connected tunnel diodes having different register states with said output signals of a first and second characteristic being provided at different register states, each said gating means including a blocking oscillator means biased for cutoff between one and another said register states, each said oscillator means responding to said output signal of one characteristic to actuate same, each said gating means further including switch means responsive to actuation of respective said oscillator means to couple respective said motor means to said power supply.

Claim 10

In a rotary wing aircraft, a vibration control system comprising a force-producing mechanism for substantially balancing out vibrations in one plane on the aircraft caused primarily by the rotating wing means, said mechanism including a first pair of weights, a first pair of electrical motors connected respectively to said weights of said first pair for rotating said weights in a clockwise direction at an average rotational angular velocity equal to a constant ratio of the angular velocity of the rotating wing means, a second pair of weights, a second pair of electrical motors connected respectively to said weights of said second pair for rotating said weights in a counterclockwise direction at an average rotational angular velocity equal to a constant ratio of the angular velocity of the rotating wing means, a source of electrical power means for sensing the vibrations in said plane and sensing the position of each said weight including; first means for sensing the vibrations on the aircraft in one direction in said plane and for producing a first output vibration signal in response thereto; second means for sensing the vibrations on the aircraft in another direcTion in said plane substantially perpendicular to said one direction and for producing a second output vibration signal in response thereto; means for combining said first and second output signals and for producing a clockwise control signal and a counterclockwise control signal; and means for sensing the angular position of each said weight and producing a weight signal in response thereto, means responsive to respective said weight signals from said first pair of weights for gating said clockwise control signal to couple and decouple said first pair of motors to said source and controlling the speed of said motors thereby altering the angular positions of said first pair of weights, and means responsive to respective said weight signals from said second pair of weights for gating said counterclockwise control signal to couple and decouple said second pair of motors to said source and controlling the speed of said motors thereby altering the angular positions of said second pair of weights.

Claim 11

In a rotary wing aircraft, a vibration control system comprising a force-producing mechanism for substantially balancing out vibrations in one plane on the aircraft caused primarily by the rotating wing means, said mechanism including a first pair of weights, a first pair of electrical motors connected respectively to said weights of said first pair for rotating said weights in a clockwise direction at an average rotational angular velocity equal to a constant ratio of the angular velocity of the rotating wing means, a second pair of weights, a second pair of electrical motors connected respectively to said weights of said second pair for rotating said weights in a counterclockwise direction at an average rotational angular velocity equal to a constant ratio of the angular velocity of the rotating wing means, a source of electrical power means for sensing the vibrations in said plane and sensing the position of each said weight including; first means for sensing the vibrations on the aircraft in one direction in said plane and for producing a first output vibration signal in response thereto; second means for sensing the vibrations on the aircraft in another direcTion in said plane substantially perpendicular to said one direction and for producing a second output vibration signal in response thereto; means for combining said first and second output signals and for producing a clockwise control signal and a counterclockwise control signal; and means for sensing the angular position of each said weight and producing a weight signal in response thereto, means responsive to respective said weight signals from said first pair of weights for gating said clockwise control signal to couple and decouple said first pair of motors to said source and controlling the speed of said motors thereby altering the angular positions of said first pair of weights, and means responsive to respective said weight signals from said second pair of weights for gating said counterclockwise control signal to couple and decouple said second pair of motors to said source and controlling the speed of said motors thereby altering the angular positions of said second pair of weights.

Claim 12

In a rotary wing aircraft, a vibration control system comprising a force-producing mechanism attached to the aircraft for substantially balancing out vibrations in one plane on the aircraft caused primarily by the rotary wing means, said mechanism including a first pair of weights rotating in the clockwise direction and a second pair of weights rotating in the counterclockwise direction, first motor means connected to each of said first pair of weights for rotating said first pair of weights at an angular velocity equal to a constant ratio of the angular velocity of the rotary wing means, second motor means connected to each of said second pair of weights for rotating said second pair of weights at an angular velocity equal to a constant ratio of the angular velocity of the rotary wing means, the axes of rotation of said weights being substantially perpendicular to said one plane, means responsive to vibrations caused by the rotary wing means in a first direction in said one plane to produce an output signal proportional to the amplitude of the vibrations in said first direction, means responsive to vibrations caused by the rotary wing in a second direction in said one plane and substantially perpendicular to said first direction to produce an output signal proportional to the amplitude of the vibrations in said second direction, means for combining said output signals and producing a clockwise and counterclockwise signal, means responsive to said clockwise signal for controlling said first motor means to alter the position of each of said first pair of weights, and means responsive to said counterclockwise signal for controlling said second motor means to control the positions of each of said second pair of weights.

Claim 13

In a rotary wing aircraft, a vibration control system comprising a force-producing mechanism attached to the aircraft for substantially balancing out vibrations in one plane on the aircraft caused primarily by the rotary wing means, said mechanism including a first pair of weights rotating in the clockwise direction and a second pair of weights rotating in the counterclockwise direction, first motor means connected to each of said first pair of weights for rotating said first pair of weights at an angular velocity equal to a constant ratio of the angular velocity of the rotary wing means, second motor means connected to each of said second pair of weights for rotating said second pair of weights at an angular velocity equal to a constant ratio of the angular velocity of the rotary wing means, the axes of rotation of said weights being substantially perpendicular to said one plane, means responsive to vibrations caused by the rotary wing means in a first direction in said one plane to produce an output signal proportional to the amplitude of the vibrations in said first direction, means responsive to vibrations caused by the rotary wing in a second direction in said one plane and substantially perpendicular to said first direction to produce an output signal proportional to the amplitude of the vibrations in said second direction, means for combining said output signals and producing a clockwise and counterclockwise signal, means responsive to said clockwise signal for controlling said first motor means to alter the position of each of said first pair of weights, and means responsive to said counterclockwise signal for controlling said second motor means to control the positions of each of said second pair of weights.

Claim 14

In a rotary wing aircraft, a vibration control system comprising a force-producing mechanism for substantially balancing out vibrations in one plane on the aircraft caused primarily by the rotating wing means said mechanism including a first pair of weights, a first pair of electrical motors connected respectively to said weights of said first pair for rotating said weights in a clockwise direction, a second pair of weights, a second pair of electrical motors connected respectively to said weights, of said second pair for rotating said weights in a counterclockwise direction, a power source for supplying power to each said motor, means for coupling and decoupling said motors from said power source to control the amplitude and phase of the centrifugal force produced by each said weight including: a speed reference generator for producing a speed reference signal proportional in frequency to the angular velocity of the rotating wing means; means for sensing the speed of each said motor and producing respective motor signals proportional in frequency to the angular velocity of respective said motor; first means for sensing the vibrations on the aircraft in one direction in said plane and for producing a first output vibration signal in reSponse thereto; second means for sensing the vibrations on the aircraft in another direction in said plane substantially perpendicular to said one direction and for producing a second output vibration signal in response thereto; means for combining said first and second output signals and for producing a clockwise control signal and a counterclockwise control signal; means for sensing the angular position of each said weight and producing a weight signal in response thereto; means responsive to said weight signals from said first pair of weights for controlling the passage of said clockwise control signal; means responsive to said weight signals from said second pair of weights for controlling the passage of said counterclockwise control signal; first storage and gating means respectively connected between said power source and respective said first pair of motors for storing said clockwise control signal and respective said motor signal and said speed reference signal; first storage and gating means being operative to couple each said motor of said first pair to said power supply when appropriate signals are stored therein and to decouple each said motor when appropriate signals are not stored therein; and second storage and gating means respectively connected between said power source and respective said second pair of motors for storing said counterclockwise control signal and respective said motor signal and said speed reference signal; and said second storage and gating means being operative to couple each said motor of said second pair to said power supply when appropriate signals are stored therein and to decouple each said motor when appropriate signals are not stored therein.

Claim 15

In a rotary wing aircraft, a vibration control system comprising a force-producing mechanism for substantially balancing out vibrations in one plane on the aircraft caused primarily by the rotating wing means said mechanism including a first pair of weights, a first pair of electrical motors connected respectively to said weights of said first pair for rotating said weights in a clockwise direction, a second pair of weights, a second pair of electrical motors connected respectively to said weights, of said second pair for rotating said weights in a counterclockwise direction, a power source for supplying power to each said motor, means for coupling and decoupling said motors from said power source to control the amplitude and phase of the centrifugal force produced by each said weight including: a speed reference generator for producing a speed reference signal proportional in frequency to the angular velocity of the rotating wing means; means for sensing the speed of each said motor and producing respective motor signals proportional in frequency to the angular velocity of respective said motor; first means for sensing the vibrations on the aircraft in one direction in said plane and for producing a first output vibration signal in reSponse thereto; second means for sensing the vibrations on the aircraft in another direction in said plane substantially perpendicular to said one direction and for producing a second output vibration signal in response thereto; means for combining said first and second output signals and for producing a clockwise control signal and a counterclockwise control signal; means for sensing the angular position of each said weight and producing a weight signal in response thereto; means responsive to said weight signals from said first pair of weights for controlling the passage of said clockwise control signal; means responsive to said weight signals from said second pair of weights for controlling the passage of said counterclockwise control signal; first storage and gating means respectively connected between said power source and respective said first pair of motors for storing said clockwise control signal and respective said motor signal and said speed reference signal; first storage and gating means being operative to couple each said motor of said first pair to said power supply when appropriate signals are stored therein and to decouple each said motor when appropriate signals are not stored therein; and second storage and gating means respectively connected between said power source and respective said second pair of motors for storing said counterclockwise control signal and respective said motor signal and said speed reference signal; and said second storage and gating means being operative to couple each said motor of said second pair to said power supply when appropriate signals are stored therein and to decouple each said motor when appropriate signals are not stored therein.

Claim 16

In a rotary wing aircraft a vibration control system comprising a force-producing mechanism for balancing out the vector sum of the vibrations in one plane on the aircraft caused primarily by the rotary wing means wherein the vector sum is divided into a pair of vector components, said mechanism including a first pair of weights rotating in the clockwise direction and a second pair of weights rotating in the counterclockwise direction, a motor connected to each of said first pair of weights for rotating said first pair of weights in said clockwise direction at an angular velocity equal to the product of the angular velocity of the rotating wing and the number of rotor blades attached thereto, a motor connected to each of said second pair of weights for rotating said second pair of weights in said counterclockwise direction at an angular velocity equal to the product of the angular velocity of the rotary wing means and the number of rotor blades attached thereto, said axes of rotation of said weights being substantially perpendicular to said one plane, first means responsive to vibrations created by the rotary wing in a first direction in said one plane to produce a first output signal proportional to the amplitude of the vibrations in said first direction, second means responsive to vibrations created by the rotary wing means at said rotor hub in a second direction in said one plane and substantially perpendicular to said first direction to produce a second output signal proportional to the amplitude of the vibrations in said second direction, means for combining said first and second output signals and for producing a clockwise control signal and a counterclockwise control signal, means responsive to said clockwise control signal for controlling said motors rotating said first pair of weights thereby altering the positions of each of said first pair of weights to substantially balance out one component of the vector sum of the vibrations created by the rotary wing means and means responsive to said counterclock wise control signal for controlling said motors rotating said second pair of weights thereby altering the positions of each of said second pair of weights to substantially balance out the other component of the vector sum of the vibrations crEated by the rotary wing means.

Claim 17

In a rotary wing aircraft a vibration control system comprising a force-producing mechanism for balancing out the vector sum of the vibrations in one plane on the aircraft caused primarily by the rotary wing means wherein the vector sum is divided into a pair of vector components, said mechanism including a first pair of weights rotating in the clockwise direction and a second pair of weights rotating in the counterclockwise direction, a motor connected to each of said first pair of weights for rotating said first pair of weights in said clockwise direction at an angular velocity equal to the product of the angular velocity of the rotating wing and the number of rotor blades attached thereto, a motor connected to each of said second pair of weights for rotating said second pair of weights in said counterclockwise direction at an angular velocity equal to the product of the angular velocity of the rotary wing means and the number of rotor blades attached thereto, said axes of rotation of said weights being substantially perpendicular to said one plane, first means responsive to vibrations created by the rotary wing in a first direction in said one plane to produce a first output signal proportional to the amplitude of the vibrations in said first direction, second means responsive to vibrations created by the rotary wing means at said rotor hub in a second direction in said one plane and substantially perpendicular to said first direction to produce a second output signal proportional to the amplitude of the vibrations in said second direction, means for combining said first and second output signals and for producing a clockwise control signal and a counterclockwise control signal, means responsive to said clockwise control signal for controlling said motors rotating said first pair of weights thereby altering the positions of each of said first pair of weights to substantially balance out one component of the vector sum of the vibrations created by the rotary wing means and means responsive to said counterclock wise control signal for controlling said motors rotating said second pair of weights thereby altering the positions of each of said second pair of weights to substantially balance out the other component of the vector sum of the vibrations crEated by the rotary wing means.

Claim 18

In the rotary wing aircraft as defined in claim 12 further comprising a speed reference generator for producing a speed reference signal proportional in frequency to the angular velocity of the rotary wing means and means for sensing the speed of each said motor and producing respective motor signals proportional in frequency to the angular velocity of respective said motors, each said motor being controlled in speed by said speed reference signal and respective said motor signal to maintain the average angular velocity of respective said weight equal to the product of the angular velocity of the rotary wing means and the number of rotor blades attached thereto.

Claim 19

In the rotary wing aircraft as defined in claim 13 further comprising a standard means for producing a reference output signal; said means for coupling and decoupling including: a pair of sensing means for sensing the speed of respective said motor means and to produce signals responsive thereto; a pair of means each receiving said reference output signal and respective said motor signal, each said register means providing a control signal of a first characteristic and of a second characteristic; and a pair of gating means connected between said power supply and respective said motor means, each said gating means being responsive to respective said control signal of one said characteristic to decouple said power supply from respective said motor means and to couple said power supply to respective said motor means in response to said control signal of the other said characteristic.

Claim 20

In a rotary wing aircraft, a vibration control system comprising a force producing mechanism for substantially balancing out vibrations in one direction on the aircraft caused primarily by the rotating wing means, said mechanism including a first pair of weights, a second pair of weights, first motor means for rotating one said weight from said said pair in opposite directions at an average rotational angular velocity substantially equal to a constant ratio of the angular velocity of the rotating wing means, second motor means for rotating the other said weight from each said pair in opposite directions at an average rotational angular velocity substantially equal to a constant ratio of the angular velocity of the rotating wing means, the axes of rotation of all said weights being substantially perpendicular to said one direction, a source of electrical power, means for coupling and decoupling said source to each said first and second motor means thereby controlling the speed of each said motor means to maintain said weights at said average rotational velocity, sensing means responsive to a change in amplitude or phase of the vibrations caused by the rotating wing means for producing control signals, said means for coupling and decoupling being responsive to said control signals thereby altering the angular movement of each said weight to compensate for such change in amplitude or phase of the vibrations.

Claim 21

In a rotary wing aircraft, a vibration control system comprising a force producing mechanism for substantially balancing out vibrations in one direction on the aircraft caused primarily by the rotating wing means, said mechanism including a first pair of weights, a second pair of weights, first motor means for rotating one said weight from said said pair in opposite directions at an average rotational angular velocity substantially equal to a constant ratio of the angular velocity of the rotating wing means, second motor means for rotating the other said weight from each said pair in opposite directions at an average rotational angular velocity substantially equal to a constant ratio of the angular velocity of the rotating wing means, the axes of rotation of all said weights being substantially perpendicular to said one direction, a source of electrical power, means for coupling and decoupling said source to each said first and second motor means thereby controlling the speed of each said motor means to maintain said weights at said average rotational velocity, sensing means responsive to a change in amplitude or phase of the vibrations caused by the rotating wing means for producing control signals, said means for coupling and decoupling being responsive to said control signals thereby altering the angular movement of each said weight to compensate for such change in amplitude or phase of the vibrations.

Claim 22

In the rotary wing aircraft as defined in claim 15 further comprising a speed reference generator for producing reference pulses having a first polarity and a given repetition rate, said means for coupling and decoupling including: a pair of sensing means for sensing the speed of respective said motor means and to produce motor pulses having a polarity opposite to said first polarity and a repetition rate which is a predetermined function of motor speed; a pair of reversible register means for receiving said reference pulses and respective said motor pulses, each said register means providing an output signal of a first characteristic when the number of said reference pulses exceeds the number of said motor pulses and of a second characteristic when the number of said motor pulses exceeds the number of said reference pulses; and a pair of gating means connected between said power supply and respective said motor means, each said gating means being resPonsive to said output signal from said register means of one said characteristic to decouple said power supply from respective said motor means and to couple said power supply to respective said motor means in response to said output signal from respective said register means of the other said characteristic.