Research of stability and transition processes of the flexible double-support rotor with auto-balancers near support

Abstract

Within the discrete model the stability of main motions and transition processes of the flexible unbalanced two-support rotor at its balancing by two passive auto-balancers located in close proximity to supports is investigated. The simplified system of differential equations describing the process of auto-balancing of the flexible rotor with respect to four Lagrange coordinates – displacements of the shaft in supports and the given total rotor unbalances is received. It is shown that the received system of equations accurate within designations matches the equations describing the process of dynamic auto-balancing of the rigid rotor on pliable supports with two auto-balancers. Therefore, main motions of the flexible rotor on condition of their existence are always steady on above resonance velocities of rotation. At velocities close to any critical velocity the conditions of existence of main motions can be violated. For expansion of the area of stability of main motions it is necessary to increase the balancing capacity of auto-balancers. Analytically (using the roots of the characteristic equation) the assessment of duration of passing of transition processes when balancing the flexible rotor is carried out. At the same time, it is established that: – transition processes are divided into: fast at which fast relative motions of corrective weights stop and the motion of rotor corresponding to the current given total rotor unbalances of the flexible rotor is established; slow at which corrective weights come to the auto-balancing positions; – at the increase in forces of resistance to relative motion of corrective weights duration of exit of corrective weights to the cruiser velocity of rotor decreases and duration of arrival of corrective weights to the auto-balancing position increases; – duration of passing of transition processes does not decrease at the reduction of the mass of corrective weights, rigidity of supports, remoteness of supports from the center of mass of the flexible rotor; – duration of passing of transition processes does not increase at the increase in the cruiser velocity of the rotor at velocities higher than the first critical (if at the same time the conditions of existence of main motions are not violated).