Expressions for vibration moments (additional dynamic loading caused by the vibrations of bearing body) during the passage of resonant zone by vibration machines with the flat vibrations of bearing body both with one arbitrarily located vibration exciter and with two self-synchronization vibration exciters for the different modes of starting are got in an analytical form. Possibilities of improvement of process of running approach of vibration machines with unbalanced vibration exciters are demonstrated by using of methods of the "double" (in case of one vibration exciter) and "separate" starting of electric motors (in case of two vibration exciters). It is shown that the first method is based on using of semislow vibrations arising in the resonant zone. The necessary condition of the successful using of this method is motion on the rotor of exciter in the moment of the repeated including of engine of rotary-type vibration moment. The conditions when the separate starting is effective are shown. Conclusions and practical recommendations that allow to facilitate starting of vibration machines with an unbalanced drive are pointed.

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Purpose. Investigation of start dynamic of the vibration machine with inertia vibration exciters considering the elastic connection of asynchronous electric motor rotors and unbalanced vibration exciter. methodology. Methods of applied theory of vibrations and method of direct division of motions are used for analytical research studies. The design of processes of running start of vibration machines is executed by using the numeral integration of equalizations of motions of the mechanical vibration system and equalizations of electromagnetic transients in asynchronous electric motors in the 'Maple' software environment. findings. It is shown that availability of elastic connection brings essential features to dynamics of vibration machine drive that should be considered when designing. Formulas for assessment of the starting deformation amplitudes and moments that occur in vibration machine drive coupling are obtained in an analytical form. It is demonstrated that oscillation amplitudes of elastic coupling at the start moment mostly depend on the remoteness of its own frequency from the current frequency in motor electricity network. An equation of coupling's torsional oscillations close to stationary rotation mode of unbalanced vibration exciter is obtained. Relation between oscillation of bearing vibration system and coupling's drive elasticity is revealed. It is found that during the start of vibration machines in case of Sommerfeld effect, resonant oscillation of elastic-damping elements (that connect motor and exciter rotors, which increase dynamic loads and energy losses in the system) excites, except resonant increase in braking vibration moment and "stopping" of engine speed. Originality. Theoretical positions of dynamics of running approach of vibration machines with inertia drive considering elastic compounds of rotors of electrical motor with limited power and unbalanced vibration exciter power got their further development. It is found that if the spring element is in the drive, natural oscillation frequencies of vibration machine are added to its critical frequencies. Practical value. The results of scientific work allow choosing options of vibration machines with unbalanced drive in a more reasonable way, which will reduce the amplitude of its start vibrations, dynamic loads and energy losses.