Feedback enhanced adaptively tuned vibration absorber
First Claim
1. A vibration absorber, for a body in which a vibrational disturbance occurs at a given frequency, said vibration absorber comprising:
- a mechanical resonator having a member for attachment to the body, a mass, and a spring connecting the mass to the member, wherein said mechanical resonator resonates at substantially the given frequency to counteract the vibrational disturbance in the body;
a magnet attached to the mass and producing a first magnetic field;
a sensor which produces a sensor signal indicating vibration due to the vibrational disturbance;
a feedback circuit connected to the sensor to receive the sensor signal and produce an output signal having first component frequency substantially equal to a harmonic of the given frequency; and
a conductor connected to the feedback circuit to carry the output signal and being mounted adjacent to one side of said mass so that a magnetic field produced by the output signal flowing through the conductor interacts with the magnetic field from the magnet to generate a force that acts on said mass thereby increasing an impedance of the vibration absorber to the vibrational disturbance.
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Accused Products
Abstract
An apparatus has a mass suspended between two mounting plates by a separate springs to form a resonant structure that absorbs vibration in a structural member to which the mounting plates are attached. Permanent magnets are fixed to opposite sides of the mass. A sensor produces a signal indicating the frequency of the vibration. A feedback circuit receives the signal from the sensor and produces an output signal having first component frequency which corresponds to a harmonic of the frequency of the vibration. The output signal is applied to a separate voice coil adjacent to each permanent magnet. The magnetic fields produced by the output signal flowing through the voice coils interact with the magnetic fields from the permanent magnets to generate forces that act on the mass in a manner that increases the impedance of the absorber to the vibration in the structural member.
55 Citations
20 Claims
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1. A vibration absorber, for a body in which a vibrational disturbance occurs at a given frequency, said vibration absorber comprising:
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a mechanical resonator having a member for attachment to the body, a mass, and a spring connecting the mass to the member, wherein said mechanical resonator resonates at substantially the given frequency to counteract the vibrational disturbance in the body; a magnet attached to the mass and producing a first magnetic field; a sensor which produces a sensor signal indicating vibration due to the vibrational disturbance; a feedback circuit connected to the sensor to receive the sensor signal and produce an output signal having first component frequency substantially equal to a harmonic of the given frequency; and a conductor connected to the feedback circuit to carry the output signal and being mounted adjacent to one side of said mass so that a magnetic field produced by the output signal flowing through the conductor interacts with the magnetic field from the magnet to generate a force that acts on said mass thereby increasing an impedance of the vibration absorber to the vibrational disturbance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An absorber for a vibrational disturbance which occurs at a given frequency in a body, said absorber comprising:
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a resonator having first and second members for attachment to the body, a mass connected by a first spring to the first member and by a second spring to the second member; a first magnet attached to one side of the mass and producing a first magnetic field; a second magnet attached to another side of the mass and producing a second magnetic field; a first sensor which produces a first sensor signal indicating vibration due to the vibrational disturbance; a feedback circuit having an input that receives the first sensor signal and having an output at which is produced a coil signal having first component frequency substantially equal to a harmonic of the given frequency; a first voice coil connected to output of the feedback circuit and mounted adjacent to the first magnet so that a third magnetic field produced by the output signal flowing through the first voice coil interacts with the first magnetic field to generate a force that acts on said mass thereby increasing an impedance of said absorber to the vibrational disturbance; and a second voice coil connected to output of the feedback circuit and mounted adjacent to the second magnet so that a fourth magnetic field produced by the output signal flowing through the second voice coil interacts with the second magnetic field to generate a force that acts on said mass thereby increasing an impedance of the absorber to the vibrational disturbance. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification