Applying Research Of The Hydraulic Driven Cooling System On Cereal Combining Harvester

The driven force of fan and pump in the traditional way of the cooling system in cereal combining harvesters comes from crankshaft of the engine by decided transmission ratio. this kind of cooling method has many problems, such as inadequate cooling of the engine when in big load low speed, and over cooling when in small load high speed. In order to solve the existing problem of cooling system of cereal combining harvesters, a new kind of cooling system has been designed in this research. The new system using hydraulic force as the driven force in the cooling fan. According to cooling water temperature the overflow-valve automatically regulates the rotational speed of the cooling fan and water pump, therefore make the engine always in an ideal temperature situation in working process.This research mainly introduced the working principle of this kind of hydraulic driven cooling system in cereal combining harvester, especially the calculation of the parameters and corresponding selection of hydraulic component elements in the system. This control system using temperature controller test the temperature of the cooling water of the engine, the over-flow quantity of the over-flow valve is controlled by the electromagnetic relay, changing the pressure of the oil, then regulate the rotating speed of the cooling fan and the pump of the engine. The main content of this research includes: the calculation of circulation quantity of the cool ing water and cooling air in the cooling system according to radiating heat to the cooling system by the engine, the calculation of the power and driven torque of the fan and the pump, according to the aftermath decide the primary parameters of the hydraulic motor and oil pump, then combing the reality of the cereal combining harvester and consult related material, choosing the type of main hydraulic components, motors, oil-pump and over-flow valve, and choosing electromagnetic relay and temperature controller; and done some contrast test of pre-heating and over-heating test of the tractor before and after the design of the system. This system design not only efficiently solved a series of problems existing in the traditional cooling system such as big starting resistance, long preheating time, inadequate cooling with low speed heavy load, overcooling with high speed light load, big fan noise,etc;. but also can fuel saving, prolong service life of the engine, raise mechanical production usefulness. This program will surely produce great social benefits and economic benefits after extensively popularizing application of this new design.