Modular vibratory force generator, and method of operating same

A modular counter-rotating eccentric-mass force generator adapted to be mounted on a structure for selectively applying a controllable vibratory force thereto, comprising:

• a plurality of modules adapted to be mounted on said structure, each module being operatively arranged to generate a fixed-amplitude variable-phase individual vibratory force on said structure at spaced locations thereon, said individual forces combining to exert a controllable-amplitude resultant vibratory force on said structure,
• each module consisting of a housing adapted to transmit vibratory force to said structure, two rotors rotatably mounted on said housing, each rotor having an eccentric center-of-mass, coupling means including gear teeth on the outer periphery of each rotor in meshed engagement for causing said rotors to rotate in opposite angular directions with a fixed angular phase relationship, and a single motor mounted on said housing and arranged within one of said rotors for rotating the rotors of the associated module;
• and
• servocontrol means adapted to be supplied with a single sinusoidal control signal and operative to cause the frequency and phase of said resultant vibratory force to be identical to the frequency and phase of said control signal and to cause the amplitude of said resultant vibratory force to be proportional to the amplitude of said control signal.