High Frequency Characteristics Of The New Electro-hydrautic Vibration Exciter

The electro-hydraulic vibration exciter is insta lled on the Vibration Rack, exciting forcegenerated by the exciter to operation in a certain area of experimental object in order to producea forced vibration. The progress of vibration table as a standard equipment in the vibration testdirectly impacts various areas of industry. The rapid development of the industry, especia llyspace area, the vibration frequency range and output are dema nded higher and higher. So, toimprove the frequency range and increase the output become a prima ry task of the technique ofresearch vibration exciter, have run throughout the course of vibration table development.The traditiona l method of electro-hydraulic excitation to control the frequency through 2Dvalve's spool circumvolve by the drive of Servo Motor, As the spool rotation in the highfrequencyexcitation process need prodigious torque, the method of drive by the Servo Motorcan not improve the frequency to a very high levels. so use hydraulic motors instead of servomotors can get a large enough torque. As the electro-hydraulic exciter system affected by thenatural frequency in the high-frequency stages,thus affecting the stability of the system. to thisend, proposed in the excitation cylinder A, B two cavity to set a variable throttle valve chamber.By adjusting the throttle valve opening to form the bypass leakage increased damping ratio, Soas to achieve the elimination of the purpose of resona nce to increase system stability. Thearticle detailed the new type of high-frequency exciter works and in accordance with fluiddynamics and system dynamics theory to establish mathematica l model of electro-hydraulicexciter, use Analytical methods to solve excitation waveform and the fina l to buildexperimental platform, analysis, comparison and research actual waveform collection. Theresults show that: The exciter can significa ntly increase vibration frequency, to achieve theabove 1200hz excitation frequency, excitation output waveform is approxima tely a sine wave.When the leakage between A,B two cavity is zero and vibration frequency achieve the natural frequency, the system will to produce a clear resona nce, a sudden increase in theamplitude of excitation waveforms. By adjusting the throttle opening can eliminate systemresona nce effectively.1．reference literature related to the research, give the overview of the ma in content of thisthesis . This chapter first introduces the mea ning and purpose of vibration test as well as thedevelopment of the status quo at home and abroad propose the ma in content of this study,purpose and innovation points.2．the structure and working principle of this electro-hydraulic vibration exciter isintroduced, analysis by establishing mathematica l model of the vibration exciter is made .3．according to hydraulic machinery and domina nt equations, the excited waveforms aresolved in the analytica l method. This part focus es on analyzing the typica l excited waveforms.4．to build a new experimental platform for electro-hydraulic vibration exciter. Use DataAcquisition System to acquire excitation waveform, then analyzed, compared and studied it.