Research On Hydraulic System Heat Banlance Of1700t·m Railway Crane

Railway crane is being used as the main heavy equipment in railway rescuingoperation. Its transmission mode is hydraulic, so the performance of the hydraulicsystem has important influence on the whole machine.Transmission andtransformation of energy in hydraulic system depends on hydraulic oil, the process oftransmission and transformation will produce loss, most of which will be passed tothe hydraulic oil, and lead to the rise of the temperature. For railway crane, thehighest temperature of oil should be lower than80°C, the biggest temperaturedefferential should be less than40°C, otherwise it will reduce the work efficiencyand influent the normal run of crane. So it has important theoretical significance andengineering application value to improve reliability of railway crane throughcontrolling the thermal balance temperature of hydraulic oil in a reasonable range.In this thesis, research of1700t·m railway crane targets a reasonabletemperature of oil through decreasing power loss and improving heat dissipationunder continuous operating mode. Firstly, based on analysis of general workingcondition of railway crane, the reason of over heating of system should be found andpower loss of main heating elements should be calculated. Secondly, the thesisanalyses the heat dissipation of parts in system and calculates heat dissipatingcapacity of main elements on account of heat transfer basic theory. Then the thermalbalance temperature of the whole system is calculated, according to the result ofcalculation, the thermal balance performace of whole system is evaluated, then themain optimization direction is given. In order to further determinate the influence ofmain elements on system, the thermal balance simulation model of railway cranehydraulic system is established. Through the analysis of simulation result, the thesisgives the evaluation of the characteristics of heat balance for hydraulic system.Based on the theoretical calculation and analysis results， related parameters ofmodel is changed, and result before and after modification is compared, then this thesis puts forwad improvements of hydraulic system. Finally, experiment andsimulation of electro-hydraulic servo system are completed, by comparing the resultsof experiment and simulation, the reliability of simulation is verified, this passagecan provide reliable and accurate reference for design and performance prediction ofrailway crane in engineering practice.