Increasing the efficiency of vibratory mechanisms by exciting low-frequency resonance vibrations

Abstract

The problems of increasing the operating efficiency of vibratory mechanisms by means of multiple combination parametric resonance are examined. It is proposed that this can be done with a parametric vibration exciter where the driving force is generated by the interaction of masses, which rock in the centrifugal inertial force field generated by a rotating rotor and in the field of gravity, with a working unit which elastic components secure to a base.Vibratory feeders and conveyors [1], vibratory mechanisms which initiate the flow of loose materials, and other vibratory mechanisms are the principal components of production-flow lines conveying the components of the glass batch and cullet in sectional and machine-tank factor works.Electrical, mechanical, and pneumatic vibratory units are used as vibrators in such mechanisms. Electromagnetic vibrators, in which ac electro-or permanent magnets are used to produce the vibrations, and electromechanical vibrators, where unbalanced masses placed on the shaft of an electric motor are used to produce vibrations, are the vibrators most widely used in the glass industry.Most vibratory mechanisms and feeders of the glassbatch components operate in a forced-vibration regime at frequencies far from resonance, as a result of which energy is not used efficiently. This is because in such frequency ranges the vibration regime of a vibratory mechanism is insensitive to and essentially independent of changes in the parameters of the technological load (a decrease of the material level in a hopper or fluctuations of the moisture content, granulometric composition, or bulk density of the transported material).A novel method of parametric excitation of vibrations of mechanical systems (RF Patents Nos. 2072660 and 2072661), which makes it possible to implement a multiple combination parametric resonance regime, can increase the operating efficiency of vibratory mechanisms.The properties of a combination parametric resonance can be analyzed for the example of a dynamic model of the vibratory setup shown in Fig. 1.The vibratory setup (see Fig. 1a ) contains a balanced rotor 1 with mass m 0 , rigidly secured to a drive shaft 2, whose rotation axis is oriented perpendicular to the vertical plane. The drive shaft is set in bearings which are held in the supports 3 rigidly tied to the working unit 3 with mass M 0 . Elastic elements 6 secure the working unit to the base 5. A damper 7 simulates friction from the technological load. It is assumed that the working unit undergoes only translational motion along the Oy axis. The coordinate system Ax ¢y ¢z ¢ whose origin lies at the center of the rotor and whose axes are parallel to the corresponding axes of the stationary coordinate system Oxyz moves translationally relative to the latter. In a position of static equilibrium the Az ¢ axis coincides with the Oz axis.The rotor has three periodically alternating open circular running tracks 8, whose centers are shifted from the rotation axis of the rotor by the same distances AB = l (see Fig. 1b ). R...