Shevtsov V. Choice and substantiation of temperature modes of operation of a hydrovolumetric mechanical transmission of a wheeled tractor

The thesis is devoted to increasing the efficiency of application the tractors based on hydrovolumetric mechanical transmissions (HVMT) through the determination of influence of temperature modes on hydrovolumetric transmission (HVT) characteristics justification of parameters of cooling system in HVT. The influence on temperature of working fluid on the work of hydro system has been carried out. There have been determined the approaches in the determination of temperature modes of HVT. The parameters of cooling system of HVT have been justified. There has been developed the extended mathematical model which considers the temperature, kinematics and power modes of volumetric hydraulic gear in HVMT of the wheel tractor. There also has been developed the mathematic model as a matrix that includes the description of kinematic parameters of HVMT, power parameters and energy conversion efficiency of all gearing parts and thermal characteristics. The provided research approved the adequacy of developed mathematical model. The variation of temperature of working fluid in the working and transport gear may be described as a curve with a maximum in a special zone. There has been determined the influence of temperature on general and volumetric energy conversion efficiency for the each gear and the recommendation for choosing the cooling system that consider the redistribution of power fluids in HVMT were performed.