Galetskij O. The energy efficient positional hydraulic drive based on pneumohydraulic dispenser with program management

The thesis for the degree of candidate of technical sciences, specialty 05.02.02 - Machine science. - National Technical University of Ukraine "Kyiv Polytechnic Institute", Kyiv, 2015. The thesis devoted to the improvement of energy efficiency and operational flexibility of positional hydraulic actuators. In the developed positional hydraulic drive energy efficiency and operational flexibility are provided by using a volume management principle which is combined with a computer (controller) control. Volume control principle realized by programmable feeding portions of the work fluid that are formed using pneumohydraulic dispenser and served in active hydraulic actuator cavity. A mathematical model of the positional hydraulic drive has been theoretically well-grounded and tested. Model tests has approved that model is operable, and also determined quantitative correlation between parameters of the actuator and frequency of pneumohydraulic supply doser portions of the work fluid, speed of the drive, velocity of the stock, the efforts on the rod and positioning precision. An experimental sample and stand has been developed to research its characteristics. Experimental study allowed to confirm the adequacy of the mathematical model and determine the characteristics of the drive. According to the research the mathematical model has been adjusted, which allowed to take into account operational environment and raise work accuracy when feedback by rod position is missed. This inaccuracy does not exceed the discrete issue of the actuator. Raising of energy efficiency of the developed drive has been experimentally verified. An engineering design technique of hydraulic actuators based on positional pneumohydraulic dispenser has been developed.