【作者】 赵尚福；

【导师】 刘昕晖；

【作者基本信息】 吉林大学 ， 机械电子工程， 2006， 硕士

【摘要】 装载机液压系统是装载机重要组成部分,液压系统过多功率损失是导致液压系统油温升高的主要原因。而以往对减少液压系统发热问题的处理方式,只是将精力集中到如何提高散热器的散热效率或增大油箱表面积,没有研究热量产生的原因,从这个意义上讲,研究发热产生的原因,设计合理的液压系统,从系统上减少热量的产生,是解决液压系统发热问题的主动做法。本论以节能为出发点,减少液压系统过多的功率损失,降低液压系统的发热为目的,为此作者对装载机的工作装置液压系统中比较大的能量损失部位进行了详细的分析,找出了系统的功率损失原因,分别对动臂下降过程中节流损失过多;工作泵不能做到工作过程压力和流量相匹配而使溢流过多;不需频繁动作的先导系统压力源先导泵的溢流过多等不合理的部分进行了改进。根据动臂下降靠自重即能降落的原理,改进原系统,设计差动回路,并在下降过程中使工作泵卸荷,减少了节流损失;将原来的单工作泵系统改为双泵系统,根据实际工作过程合分流,使压力和流量相匹配而减少溢流损失;把原来的先导系统压力源先导泵用蓄能器取代,当转向系统不工作时转向泵给蓄能器充油,让它给先导系统做油源,这样减少了能量损失。又通过对改进系统做了大量的分析和实验,以及和原系统的比较,最后得出各部分改进系统的实用性和可行性,达到了节能的目的。更多还原

【Abstract】 Loader is a kind of high efficiency, wide use machine。It is apply inextensively in the engineering, such as building, mineral mountain, railroad,highway, electricity of water, port, the farmland capital construction and nationaldefense...etc., it has important function to reduce the labor intensity of drivers,quicken the working speed of engineering constructs, improve engineering quality,Whether at domestic or international, loader develop in variety and quantity at ahigh speed, it is one of the important engineering machine, compose of powertransmission system, stepped device, work equipment, turnaround braking system,hydraulic system and manipulate system .Its hydraulic system include the workdevice hydraulic system 、 turnaround hydraulic system and gear-box hydraulicsystem in generally. Loader’s hydraulic system will make oil to high temperature inusing process. According to research, loader oil’s exorbitant temperature is a mainfactor to affect reliability of system and component and the work efficiency. so howto ensure loader’s hydraulic system work in natural is a key to ensure loader workin natural.In loader, hydraulic system use oil as a medium in order to achieve the powertransition. According Bernoulli equation when liquid is flowing, because ofglutinosity it will cause power losing, reduce efficiency of system. In the pressureoil road that the hydraulic system, because pressure is far larger than kinetic energyand potential energy, the lost power is pressure losing. The losing of hydraulicsystem on the one hand make efficiency of system low, on the other hand the losingpower will translate to heat energy, make the oil’ temperature higher, and makedevice fault. But former processing method of the hot equilibrium problem ofhydraulic system is just concentrate on how to raise hot spread effect, have noresearch the reason of fever creation, by this meaning, study the reason of fevercreation and reduce the fever creation and make reasonable hydraulic system,reducing the energy loss, is active way of resolves the fever the problem ofhydraulic system.This text make a analysis of power losing of hydraulic system of loader’swork device , it found the reason of power losing and point which part haveproblems。According to this problem we improve those parts and make a lot ofanalysis and tests and make compare with primary system, At last, it conclude thefeasibility of improved system.This text is divided to five chapters:Chapter 1, it introduces to loader’s development trend in domestic andinternational, generalize the order and important meaning of economy energy ofhydraulic system .at the point of purpose and meanings of economy energy, weintroduced the source and an articles topic of this contents.Chapter 2, it made a detailed introduction towards arm work systemimprovement, first we analyzed the reason of energy losing in work. Then, weanalyzed the losing of the pressure of the original system, particularly made a detailanalysis of the oil loss which passed through multi-valve. We also make a lot ofimprovement aim at the original system , through analyzing energy loss of newsystem and carry on two systems comparison, we make a conclusion that the newsystem make less loss pressure power than original system, and then through theanalysis to speed of descend, get improve the reliability of system.Chapter 3 , accumulator replaces the forerunner pump as forerunnersystem ,first introduce the principle and structure of original system, , and pointedthe weakness, then put the forward with the new system of the accumulator, andintroduced the principle structure, point out advantage of use accumulator asforerunner oil source , through the work principle of decompression valve ,and thenthrough from accumulator to the cavity analyzing hydraulic system , and getfunction relation, and through function conclude possibility of accumulator as firstsystem provide the oil.Chapter 4 make a detailed introduction towards economy energy analysis ofloader work pump, first analysis the work principle of the original system, from theprocess of analysis , found out the unreasonableness of lose energy of high ratio oforiginal system , then put forward the necessity of the improve system, and thenaim at the original system designed reasonable system, introduced the workprinciple of the improvement system, through the analysis, get advantage of theimprovement economy energy system, and then through experiment curve,compared with new and original systems, and we gets, although the improvementsystem has the variety of the discharge in the process of double pump confluenceand reposition of redundant personnel, bur it did not affect stability of loader, thenew system is stable.Chapter 5 Conclusion, this text through improving a few unreasonablepositions of hydraulic system, coming to a purpose of economy energy andpromoting hot balance, make a meaningful trial of developing more economyenergy loader next step.更多还原