Research of Antiresonance Three-Mass Vibratory Machine With a Vibration Exciter in the Form of a Passive Auto-Balancer

A three-mass anti-resonance vibratory machine with a vibration exciter in the form of a passive auto-balancer has been analytically synthesized. In the vibratory machine, platforms 1 and 2 are visco-elastically attached to platform 3. Platform 3 is visco-elastically attached to the base. The motion of loads relative to the auto-balancer housing is hindered by the forces of viscous resistance. A theoretical study has shown that the vibratory machine possesses three resonance frequencies and three corresponding forms of platforms' oscillations. Values for the parameters of supports that ensure the existence of an anti-resonance form of motion have been analytically selected. Under an anti-resonance form, platform 3 is almost non-oscillating while platforms 1 and 2 oscillate in the opposite phase. In the vibratory machine, platform 1 can be active (working), platform 2 will then be reactive (a dynamic vibration damper), and vice versa. At the same time, the vibratory machine will operate when mounting a vibration exciter both on platform 1 and platform 2. An anti-resonance form would occur when the loads get stuck in the vicinity of the second resonance frequency of the platforms' oscillations. Given the specific parameters of the vibratory machine, numerical methods were used to investigate its dynamic characteristics. Numerical calculations have shown the following for the case of small internal and external resistance forces in the vibratory machine: ‒ theoretically, there are seven possible modes of load jam; ‒ the second (anti-resonance) form of platform oscillations is theoretically implemented at load jamming modes 3 and 4; ‒ jamming mode 3 is locally asymptotically stable while load jamming mode 4 is unstable; ‒ for the loads to get stuck in the vicinity of the second resonance frequency, one needs to provide the vibratory machine with the initial conditions close to the jamming mode 3, or smoothly accelerate the rotor to the working frequency; ‒ the dynamic characteristics of the vibratory machine can be controlled in a wide range by changing both the rotor speed and the external and internal forces of viscous resistance. The results reported here are applicable for the design of anti-resonance three-mass vibratory machines for general purposes