装载机行走液压驱动系统研究

发布时间：2018-07-27 20:51

【摘要】：装载机被广泛应用于公路、铁路、港口、水利、军工等各项建设工程,是用途最广泛的工程机械之一。目前,我国一般中大型装载机普遍采用液力机械传动,该传动方式存在效率与动力之间不协调的传动特性,低速大扭矩时效率低。随着液压元件精度的不断提高、液压系统的功能不断强大、效率和性能的不断提升,液压传动的应用范围也在不断地扩大,原来只能用机械或者液力机械传动的机械如推土机、平地机、装载机,现在也可以用液压系统作为行驶驱动的传动形式,可以解决这类机械作业过程中载荷频繁大范围变化而引起的液压冲击、效率低、爆管等现象。研究大中型装载机采用液压传动行驶驱动系统,充分利用液压传动的优势,将具有广泛的工程实际意义。本文在对装载机作业特性分析的基础上,分析了装载机采用液力传动存在的问题,提出了装载机采用液压驱动系统的方案及控制策略,根据发动机与液压系统的匹配原则、动力学和运动学分析结果、液压系统压力设定原则,对柴油发动机、液压泵、液压马达等主要元件进行了选择匹配。最后,应用AMESIM仿真平台,建立了两档装载机行走液压驱动系统模型和无级装载机行走液压驱动系统模型,从起步、对阶跃负载的响应和对正弦波动载荷的响应三个方面,进行仿真分析对比。得出了系统的压力平稳性和柴油发动机耗油量方面,无级系统优于两挡系统的结果。
[Abstract]:Loaders are widely used in various construction projects such as highway, railway, port, water conservancy and military industry. It is one of the most widely used engineering machines. At present, hydraulic mechanical transmission is widely used in the general medium and large loaders in our country. The transmission mode has the characteristics of uncoordinated transmission between efficiency and power, low speed and large torque. The function of the hydraulic system is constantly improving, the function of the hydraulic system is constantly strong, the efficiency and the performance are continuously improved. The application range of the hydraulic transmission is constantly expanding. The machine that can only be driven by mechanical or hydraulic machinery, such as bulldozer, leveler, loader, can also use the hydraulic system as driving drive form. In this kind of mechanical operation, the hydraulic impact, low efficiency and tube explosion caused by the frequent and large variation of load in this kind of mechanical operation are solved. It is of great practical significance to study the hydraulic drive driving system for large and medium loaders, and make full use of the advantages of hydraulic transmission. This paper is based on the analysis of the loader's operating characteristics. The problems existing in the hydraulic drive of the loader are analyzed. The scheme and control strategy of the hydraulic drive system of the loader are put forward, according to the matching principle of the engine and the hydraulic system, the dynamic and kinematic analysis results, the principle of the pressure setting of the hydraulic system, and the selection of the main components of the diesel engine, the hydraulic pump and the hydraulic motor. Finally, using the AMESIM simulation platform, the model of the hydraulic driving system of the two gear loader and the model of the walking hydraulic drive system of the stepless loader are set up. From the starting point, the response to the step load and the response to the sinusoidal wave load, the simulation analysis is carried out. The pressure stability of the system and the diesel engine are obtained. In terms of fuel consumption, the stepless system is better than the two block system.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH243;TH137

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