DESIGN AND ANALYSIS OF NOVEL ACTIVE ACTUATOR TO CONTROL LOW FREQUENCY VIBRATIONS OF SHAFT SYSTEM

Aiming at providing with high-load capability in active vibration control of large-scale rotor system,a new type of active actuator to simultaneously reduce the dangers of low frequency flexural and torsional vibrations is designed.The actuator employs electro-hydraulic system and can provide a high and circumferential load.To initialize new research,the characteristics of various kinds of active actuators to control rotor shaft vibration are briefly introduced.The purpose of this paper is to introduce the preliminary results via presenting the structure,functions and operating principles,in particular,the working process of the electro-hydraulic system of the new actuator which includes a set of high speed electromagnetic valves and a series of sloping cone-shaped openings,and presenting the transmission relationships among the control parameters from control signals into the valves to active load onto shaft.The course of the work is dynamic,and a series of spatial forces and moments are put on the shaft to get an external resultant force to reduce excitations that induce vibration of shafts.By checking states of vibration,the actuator can control the impulse width and the interval of injection time for applying different control force to a vibration shaft in two circumference directions through the regulating action of a set of combination directional control valves.The results from simulating analysis and experiment show evidence of that this design can satisfy the case of active process of decreasing of flexural and torsional vibrations.