Study On Electro-hydraulic Proportional Control Pump(Motor)

This paper summarizes first the general situation of development in the electrohydraulic proportional control technology. Specifically it demonstrates that,the appearance of electrohydraulic control elements provides the technical guarantee for automation of control engineering,and appearance of proportional volume control provides the technical suppots for power saving of large horsepower systems ;Practical or immediate significance for reseaching a new type of electrohydraulic control pump(mator) of sawing power is expained.In this paper the principle of a new type of proportional volume controler is indrouduced. The volume controller is a displacement control system, which is consists of an electro-amplifier. Two-way proportional valve controlled disfferantinal area piston and electro-displacemet sensor,that is a closed loop system.so that the displacement of volume controller of the pump(motor) is proportional to electrical signal via elero-amplifier.The static and dynamic characteritics of the volume controller were analyzed .In the static analyses the static equations were obtained; In the dynamic analyse,the classical control theory is adoped.Transfer function and frequency response is used for theoretical analyses and synthesize, the stability ( margin of stability) and band-width finaly were obtained.Under test of the volume controller,the curves of statical control and load characteristics and curves of step response for dynamic characteristics can be obtained.Theoretical analyses and experimental reseach prove that the controlling characteristics of the proportional control pump(motor) are satistying,and have reached requirements for consumers, so that the electrohydraulic proportional control pump(motor) development by author have be appled in practice. As electrohydraulic proportional control pump(motor) associate whit technology of electronic and computer, the volume transmission are more perfect, so that vast vistas will be obtained for practical applications in the large horsepower system.