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高空作业车的液压系统设计【8张CAD图纸+毕业论文】【答辩通过】

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关键词：: 高空作业液压系统

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摘要

高空作业车是用来运送工作人员和工作装备到指定高度进行作业的特种车辆，是将高空作业装置安装在汽车底盘上组成的。高空作业装置包括工作臂、回转平台、副车架、工作斗、液压系统和操纵装置等。现在的高空作业装置具有操作平顺、工作稳定、自动调速、安全可靠等优点，大大提高了空中作业的工作效率。高空作业车是利用汽车底盘作为行走机构，具有汽车的行驶通过性能，机动灵活，行驶速度高，可快速转移，转移到作业场地后能迅速投入工作，因此被越来越多的应用在工程建设、工业安装、设备检修、物业管理、航空、船舶、石化、电力、影视、市政、园林等许多行业，是近几年来国内发展最快的专用汽车产品之。

关键词: 高空作业车；液压系统；泵站

ABSTRACT

Aerial word truck is used to transport personnel and equipment to the designated special vehicle height work, is the aerial device installed in the automobile chassis. Aerial device comprises a working arm, rotating platform, side frame, basket, hydraulic system and control device. Aerial device now has the advantages that the operation is smooth, stable operation, automatic control, safe and reliable, greatly improving the working efficiency of the air. Aerial vehicle is the automobile chassis as a running mechanism, has the vehicle performance, flexible, high speed, fast transfer, transfer to the job site to work quickly, so it is more and more used in many industry construction, industrial installation, equipment maintenance, property management, aviation, ships, petrochemical, electricity, television, municipal, gardens, is one of the most rapid development in recent years of dedicated automotive products.

Keywords : operating vehicle height ; hydraulic system ; Pump stations

摘要III

AbstractIV

目录V

1 绪论1

1.1 引言1

1.2 高空作业车的发展概况2

1.2.1 概况2

1.2.2 国外趋势与动向3

1.3 国内现状、差距与如何提高的方法4

1.3.1 现状4

1.3.2 差距4

1.4 液压传动概况5

1.4.1 液压传动的定义5

1.4.2 液压传动的发展概况5

1.4.3 液压传动系统的组成6

1.4.4 液压传动的优缺点6

1.4.5 液压系统的设计步骤与设计要求6

1.5 课题简介9

1.5.1选题的必要性9

1.5.2 课题主要研究的内容及目的10

2 设计要求11

2.1 总体设计要求11

2.2 动作要求11

2.3 技术性能要求12

3 确定设计方案12

3.1 总体设计方案12

3.2 确定执行元件的形式12

3.3 液压系统的设计步骤12

3.4 整体设计结构图13

3.5 液压系统14

3.5.1 液压系统工作原理14

3.5.2 液压系统原理图15

4 液压系统计算16

4.1 液压缸的设计计算16

4.1.1 液压缸的最大载荷16

4.1.2 确定系统工作压力22

4.1.3 液压缸的内径计算22

4.1.4 液压缸缸筒壁厚和外径计算22

4.1.5 液压缸活塞杆直径24

4.1.6 液压缸活塞杆强度校核25

4.1.7 液压缸活塞杆稳定性校核26

4.1.8 液压缸的工作压力27

4.1.9 液压缸的流量28

4.1.10 液压缸选择29

4.2 液压泵的选择29

4.2.1 计算液压泵的流量29

4.2.2 计算液压泵的压力30

4.2.3 选择液压泵30

4.3 电动机的选择31

4.4 管路的选择32

4.5 其他辅助元件的选择32

4.5.1 虑油器32

4.5.3 油箱34

5 阀板的设计36

5.1 阀的集成形式36

5.1.1 有管集成36

5.1.2 无管集成36

5.2 无管集成液压控制装置的设计流程36

5.3阀块的设计37

5.3.1 整体设计方案37

5.3.2 阀块的设计37

6 泵站设计42

6.1 泵站概述42

6.2 泵站设计目的42

6.3 泵站的连接和安装方式43

6.3.1 液压泵的安装方式43

6.3.2 电动机与液压泵的连接方式43

6.4 防震降噪措施43

7 结论与展望44

7.1结论44

7.2展望44

致谢45

参考文献46

1 绪论

1.1 引言

高空作业车按工作臂的型式，有四种基本型式，分别为：垂直升降式、

折叠臂式、伸缩臂式和混合臂式。垂直升降式高空作业车的升降机构只能在垂直方向上进行运动。它的主要特点是结构简单，承载能力强，但作业范围小，作业高度低，这种结构型式应用比较少。折叠臂式高空作业车工作臂之间的连接全部采用铰接型式，所以国外又把它叫做铰接式高空作业车。折叠臂高空作业车结构适合于较低作业高度的车型，如要加大作业高度，必然要增加臂长或增加工作臂数量，增加臂长会使作业车体积庞大，降低灵活性；增加工作臂数量会造成操作繁琐，安全性降低。伸缩臂式的高空作业车在行驶状态时，工作臂缩回套叠，工作时伸出，可以有效增大作业高度，同时具有工作效率高、操作简单、动作平稳等特点。混合臂式高空作业车工作臂之间既有铰接，也有伸缩，是折叠臂式和伸缩臂式高空作业车的结合，它综合了两种结构型式的优点，工作性能最好，但结构也最为复杂。

1.2 高空作业车的发展概况

1.2.1 概况

高空作业机械是在工程起重机械基础上发展起来的产业系统，只有二十几年的历史。尽管我国在高空作业车设计制造上取得了一些成绩，但是国内生产制造的高空作业机械同国外同类型高空作业机械产品相比仍有一定差 ,主要表现为技术含量低、大型的较少、结构笨重、作业时微动性能差等问题。高空作业车在世界上已有近四十年的发展历史，现已形成一个完整的专用产品研发、生产体系。如美国的CROVE(格洛夫)、GENIE(吉尼)、英国的COLES (西蒙)，意大利的RICO (利高)，芬兰的BRONTO(布朗托)公司等，并且它们各有侧重，如BRONTO侧重于高空消防车系列，COLES侧重于车载高空作业平台等。高空作业车发展到现在，其作业高度最高已到达72m(BRONTO公司生产)，作业车的可靠性、安全性、舒适性、操作方便和简单的直接性等方面都有较大提高，而且随着电子计算机的普及和发展以及机、电、液一体化研究的进展，国外各大公司竞相采用电脑(电子)操控系统，提高整机性能，减少整机液压元件的使用，减小整机体积及重量，提高操控的灵敏度。

在我国，虽然对高空作业车的研制、生产起步较晚，但是随着我国经济的快速发展，高空作业车的使用面、服务领域不断扩大，现正处于较快的发展阶段，特别是各生产厂家积极引进和消化国外先进技术，开发新品种，提高产品技术和质量水平，已有部分达到或接近国际同类产品的水平。如浦沅集团公司已能生产作业高空6m到60m共12种规格近30个品种的高空作业车，杭州园林机械厂引进日本先进技术和管理经验，在近几年内开发出适合国内用户需要的l0多个新品种，能生产26m 内的各种绝缘及通用高空作业车，形成年产350台以上的生产能力，占有国内中小高度高空作业车市场50％左右的份额，并有部分产品出口；抚顺起重机总厂锦州重型机械股份有限公司和徐州重型机械厂针对国内大高度消防救援作业车依赖进口状况，先后开发了30m 以上的高空消防作业车，产销良好，深受用户欢迎；徐工集团生产非常适合路灯、隧道维护使用的20m 以内的高空作业车，并完成了53m大高度高空消防车的研制。有关专家预测，我国高空作业车在未来几年仍将保持较高的产销增长率，特别是大中城市基础设施建设和维护等方面的需求增长更快。

然而现阶段我国高空作业车发展中还存在许多问题：1、大多数厂家产品单一，型号老化，产量小，企业规模小；2、部分企业技术创新能力较差，技术储备明显不足，市场经营范围窄，企业效益差；3、国内基础材料的质量参差、研发水平又较低，基础零部件配套水平较差，许多原材料依赖进口；4、基础零部件配套厂家少，规格品种少，产品质量、性能可靠性不高，不稳定；5、专业化、机械化生产水平低，工艺落后，装配水平较低；6、主机(底盘)型号单一，不能满足生产厂的组装要求，直接影响新产品的开发；7、产品的售后服务水平较差，缺乏专业的检测和维修设备，维修人员专业技能不足，未形成善的售后服务体系；8、对高空作业车等专用车的管理上，有关政策滞后，不利于特种高空作业车的小批量改装、生产。

为了适应我国高空作业车发展的需求，笔者认为，要着眼于长远目标，走规模化、标准化、集约化、产品配套化、系列化的道路；要尽快地培养高素质的专业人才，要建立一套适合国际标准的生产体系和质量体系，在高空作业机械国际标准化组织(TC214)已有的标准范围之外，建立适合我国的标准化质量体系，以防止国外技术垄断；各厂家要做到强强联合，在研发上与高校及专业研究机构联合研发，加快相关产品的研制和研究成果的生产转化，提高产品质量，避免各自为营的现象；要能带动国内基础零件配套产品的发展，使之形成完整的生产体系、配套体系，同时，形成几家在技术力量、产品质量、人才储备上能达到国际先进水平的配套件生产厂家。

尤其在现阶段，笔者认为要优先做好以下产品和技术的研发：l、建筑用自行式作业平台和蜘蛛式作业平台；2、带电作业(10KV 以上)的绝缘高空作业车；3、25m 以上多功能消防救援高空作业车；4、室内外轻型作业平台；5、大作业幅度平台及新型多功能高空作业车；6、高空作业机械的自动控制和安全保护技术的研制；7、机、电、液一体化技术在高空作业车上的应用。

1.2.2 国外趋势与动向

国外高空作业机械属新兴行业，是在工程起重机械基础上发展起来的高新技术产业系统，只有二十几年的历史。目前，专业生产高空作业机械的公司比较少。近年来，由于汽车起重机销售量下降及市场平淡，一批汽车起重机制造公司，相继发展高空作业机械，但总计年产量仍不能满足市场需求，正处于发展时期。

国外高空作业机械，发展迅速，技术水平不断提高。工业发达国家，一般都有专门的跨国公司和集团主营和兼营高空作业机械，如美国GROVE公司(格鲁夫)和GENIE(吉尼公司)、英国COLES公司、ST-MON公司(西蒙)、意大利RICO(利高)、芬兰BRONTO公司(波浪涛公司)、日本的多田野和爱知株式会社等。高空作业机械的底盘分通用型和专用型，采用通用汽车底盘的高空作业机械，机动灵活，能快速转移，作业高度较高，采用专用底盘的高空作业机械，即自行式高空平台车，适用于固定场所作业，具有微动行驶，扩大作业半径等特点。

为了满足实际工程的需要，高空作业车的作业高度越来越高，随之作业半径也越来越大。如西蒙公司S600高度已达62 m、芬兰BROTO公司产品最高己达72 m，自命为“天梯”，高空作业车的下车、工作斗均采用微机进行操纵。

操作越来越简单可靠，自动化程度不断提高。如GENIE〔吉尼公司)的自行式直臂式高空作业车、自行式曲臂式高空作业车、自行式剪型高空作业车。由于采用自动化控制，高空作业车的微动性能好，定位也来越来越准确。

但根据不同的工况条件，考虑到造价等原因，拖动式和手动式很有实用价值，目前在一些场所仍被广泛使用。此类高空作业车有拖动式曲臂高空作业车和手动式物料升降机。

高空作业车的发展主要动向是实现六化、三性，以提高高空作业机械的适用性。六化: 即液压化、最优化(采用计算机辅助设计)、轻量化(采用高强度材料、减轻构件重量)、机电液一体化(如安全保护、报警装置等)、通用化、系列化。三性:可靠性、安全性和舒适性。

为了满足高层建筑的复杂情况，要求人们不断改进举高车，以适应施工、灭火等需要，以及举高车制造公司间日趋激烈的竞争，促进了举高车技术的发展。新技术的采用，使发达国家80年代的举高车在性能和安全上有较大的提高，这主要体现在三个方面:

(1) 在公安消防上，提高救生和灭火能力。在80年代，发达国家通过改进举高消防车的臂架结构和液压系统，使其救人和灭火能力有了大幅度的提高。登高平台消防车，70年代的最大工作高度是40m, 80年代后期，芬兰波浪涛公司又推出67.5m的登高平台消防车，而且这两种车的登高平台载重能力达450比，显著地提高了救生能力。

(2 )提高应付不利环境的能力。在高层建筑火场上或在施工现场上，有时会遇到地面不平、场地狭窄等情况。如何在这些不利情况下使举高车充分发挥救生和灭火能力或载人施工的能力，也是举高车新技术开发的主要方向之一。在这方面比较突出的日本森田泵公司，在新一代云梯消防车上采用了电子计算机调平技术。

(3) 提高安全性。如在80年代德国的马基路斯、麦茨、森田和芬兰的波浪涛公司等纷纷采用了靠电子计算机控制举高消防车的支腿梯架的操作和显示等技术，这种技术提高了云梯操作自动化程度，从而避免了因操作人员的失误而导致的危险。

1.3 国内现状、差距与如何提高的方法

国内高空作业机械发展刚刚起步，只有十几年的发展历史，虽然起步晚，由于高空作业机械制造企业的努力，已逐步走向稳定的发展轨道。

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内容简介：: 无锡太湖学院毕业设计（论文）开题报告题目：高空作业车的液压系统信机系机械工程及自动化专业学号： 0923046 学生姓名：贡涛指导教师：林承德（职称：教授）（职称：）2012 年 11 月课题来源江苏省苏州金龙客车有限公司科学依据（包括课题的科学意义；国内外研究概况、水平和发展趋势；应用前景等）高空作业车是用来运送工作人员和工作装备到指定高度进行作业的特种车辆，是将高空作业装置安装在汽车底盘上组成的。高空作业装置包括工作臂、回转平台、副车架、工作斗、液压系统和操纵装置等。现在的高空作业装置具有操作平顺、工作稳定、自动调速、安全可靠等优点，大大提高了空中作业的工作效率。高空作业车是利用汽车底盘作为行走机构，具有汽车的行驶通过性能，机动灵活，行驶速度高，可快速转移，转移到作业场地后能迅速投入工作，因此被越来越多的应用在工程建设、工业安装、设备检修、物业管理、航空、船舶、石化、电力、影视、市政、园林等许多行业，是近几年来国内发展最快的专用汽车产品之一。研究内容1、设计任务：高空作业车的液压系统设计2、机器用途：通用型，适用于建筑、安装、管道铺设等高空作业。3、工作环境：风力六级以下，温度-2030 ，无腐蚀性极易爆易燃性气体。4、作业部分主要技术参数最大作业高度： 11-12米最大作业半径： 5.5米回转角度： 360 额定平台载荷： 200kg 操作方式：下操作、上操作可以任意选择。支腿形式/数量： H型/4 旋转速度： 0-3r/min 两支臂变幅时间：起臂：t70s 落臂：t6045s 支腿收放时间：收支腿：t60s 放支腿：t60s拟采取的研究方法、技术路线、实验方案及可行性分析1、回转台左右均可以全周回转360。2、起升和旋转可以同时互不干涉的动作。3、垂直支腿在高空作业车非工作状态下可以自由缩放。4、水平支腿在高空作业车非工作状态下可以自由的扩放支腿的支承范围。5、制动液压缸可以随时制动回转马达的转动。动作平稳、安全可靠、操作方便、体积小、自重轻研究计划及预期成果本课题金龙客车的高空作业车液压系统为对象，对该车重要系统-液压部分系统进行设计和研究，以实现高空作业车的工作稳定、可靠，安全。主要研究过程如下：1、收集、分析、消化原始资料，了解熟悉目前高空作业车液压系统的设现状，控制方法，主要元器件及有关技术参数分析存在的问题。2、液压系统设计确定液压系统方案确定液压系统控制方式液压元器件的选择和有关计算3、绘制标准液压系统工作图预期成果：制定出合理液压系统方案以致使工作臂和支腿实现预定的运动，保证作业车安全可靠的运行。特色或创新之处液压传动与机械传动、电气传动相比有以下主要优点： (1) 在同等功率情况下，液压执行元件体积小、重量轻、结构紧凑。例如同功率液压马达的重量约只有电动机的1/6左右。 (2) 液压传动的各种元件，可根据需要方便、灵活地来布置； (3) 液压装置工作比较平稳，由于重量轻，惯性小，反应快，液压装置易于实现快速启动、制动和频繁的换向；(4) 操纵控制方便，可实现大范围的无级调速(调速范围达2000：1)，它还可以在运行的过程中进行调速； (5) 一般采用矿物油为工作介质，相对运动面可自行润滑，使用寿命长； (6) 容易实现直线运动； (7) 既易实现机器的自动化，又易于实现过载保护，当采用电液联合控制甚至计算机控制后，可实现大负载、高精度、远程自动控制。 (8) 液压元件实现了标准化、系列化、通用化，便于设计、制造和使用。已具备的条件和尚需解决的问题已具备的条件：电脑；相关开发软件；部分技术资料。尚需解决的问题：学习UG软件；确定产品的结构尺寸和技术要求；逆向设计建立三维数模；总成运动仿真校核。指导教师意见指导教师签名：年月日教研室（学科组、研究所）意见教研室主任签名：年月日系意见主管领导签名：年月日翻译部分英文部分： The hydraulic actuator is the hydraulic pump provides hydraulic energy into mechanical energy conversion device, which comprises hydraulic cylinders and hydraulic motors. Output rotational movement of the hydraulic actuator is a hydraulic motor habits, while the output of the linear movement (including output swing movement) of the hydraulic actuator element is referred to as the hydraulic cylinder. A hydraulic motor characteristics and classification The hydraulic pump and the hydraulic motor is a reversible hydraulic components, from the viewpoint of energy conversion can be input to any one of the hydraulic pump working fluid, it becomes a hydraulic motor working conditions; Conversely, when the main shaft of the hydraulic motor by the outer the torque driven to rotate, but also becomes hydraulic pump conditions. Because they have the same basic structural elements - sealed and may periodically change the volume and corresponding with the oil bodies. However, due to different operating conditions of the hydraulic motor and a hydraulic pump, the performance requirements are not the same, so there are still many differences between the hydraulic motor and a hydraulic pump of the same type. First hydraulic motor should be capable of being reversed and thus requires that its internal structure symmetry; hydraulic motor speed range needs to be large enough to have certain requirements, in particular its minimum steady speed. Therefore, it is usually the use of rolling bearings or hydrostatic bearings; second hydraulic motor due to an oil under the conditions of the input pressure, and thus do not need to have a self-priming ability, but needed the certain initial sealing performance, in order to provide the necessary starting torque. Due to the existence of these differences, so that the hydraulic motor and the hydraulic pump is relatively similar in structure, but not reversible. Hydraulic motor in accordance with knot plum type can be divided into gear, vane, piston, and other types. Divided into high and low speed two categories according to the hydraulic motor rated speed. Higher than the rated speed 500r/min is a high-speed hydraulic motor, rated speed less than 500r/min is a low-speed hydraulic motor. The basic types of high-speed hydraulic motor gear, screw, vane and axial piston. Their main characteristics is the high speed, small moment of inertia, easy starting and braking, adjust high sensitivity (speed and commutation). Often, speed hydraulic motor output torque (N m of only tens to hundreds of N m), it is also known as a high-speed low torque hydraulic motor. Basic types of low-speed hydraulic motor is a radial piston type, in addition to low-speed axial piston, vane and gear structure type, the main features of the low-speed hydraulic motor is large displacement volume low speed (sometimes up to a few turns per minute or even a few tenths of turn), it can be directly connected with the working bodies do not need to slow down the device, the transmission mechanism greatly simplified, usually low-speed hydraulic motor output torque (up to several thousand N m tens of thousands N m), it is also known as the low speed high torque hydraulic motor. Second, the hydraulic motor operating principle 1 Vane hydraulic motor Due to the role of pressure oil, the uneven rotor torque. Vane hydraulic motor output torque and the displacement of the hydraulic motor and the hydraulic motor and out of the pressure differential between the ports, its speed is determined by the size of the input flow rate of the hydraulic motor. Hydraulic motors are generally required to reversing radial vane hydraulic motors leaves placed. In order to make the blade root always through the oil pressure in the back pressure chamber Walter blade root path should be set to a one-way valve, in order to ensure that the vane hydraulic motor in the normal pressure oil Walter, the top of the blade and The inner surface of the stator in close contact in order to ensure a good seal, and therefore should be set to the blade root to the preload spring. Vane hydraulic motor small size, small moment of inertia, quick action, applicable to the commutation frequency is higher, but the large amount of leakage, low-speed operation is unstable. Vane hydraulic motors are generally used for high speed, torque is small and the operational requirements of sensitive occasions. 2 radial piston hydraulic motor Figure 3-2 radial piston hydraulic motor schematic when pressure oil fixed oil distribution shaft 4 window into the bottom of the cylinder inner plunger 1, the plunger extends outwardly tightly top live in the inner wall of the stator 2 and the eccentricity e, due to the presence of the stator and the cylinder block. The plunger in contact with the stator, the stator of the reaction force of the plunger. The force can be decomposed into two components. When the fluid pressure acting on the bottom of the plunger p, plunger diameter D, the angle between the force and Duration, they were and produce a torque force on the cylinder, the cylinder rotation. Cylinder and then connected to the drive shaft through the end face outward output torque and speed. The above analysis of a torque generated by the plunger role in the pressure chamber there are several plunger, the plunger torque generated by rotation of the cylinder, and the output torque. Radial piston hydraulic motor is used for low speed and high torque. 3 axial piston motor Axial piston pump valve with flow, other forms of principle can be used as a hydraulic motor, axial piston pumps and axial piston motor is reversible. Axial piston motor works as shown, with the oil pan and the swash plate fixed and 5 and the cylinder of the motor shaft connected to rotate together. When the pressure oil through the oil pan window into the cylinder plunger hole, the plunger 3 in the pressure oil under the overhang, the plunger against the swashplate swashplate 3 generates a method to the reaction p This force can be decomposed into axial and vertical component where. Where and plunger hydraulic pressure phase equilibrium, where the plunger creates a torque on the center of the cylinder, driven by the motor shaft rotates counterclockwise. Axial piston motor instantaneous torque pulsation. If you change the motor oil pressure input direction, the motor shaft 5 rotates clockwise. The inclination of the swash plate is a change, i.e. the change of the displacement, not only affects the torque of the motor, but also affects its speed and direction. The greater the inclination angle of the swash plate, the greater the torque is generated, the lower the speed. 4. Gear hydraulic motor Gear motor on the structure in order to adapt to reversing requirements out of the oil port equal to the symmetry have separate external case drain the bearing portion of the leakage of oil leads to the outside of the housing; uses rolling in order to reduce the start friction torque; torque in order to reduce the The pulsating hydraulic gear motor Teeth more than the number of teeth of the pump. Gear hydraulic motor worse by the dry tightness, Yung rent less efficient input pressure is not too high, you can not have a greater torque. With the change of position of the engagement point and the instantaneous speed and torque varies, the hydraulic gear motor therefore only suitable for the occasion of the high speed and small torque. General with a dry construction machinery, agricultural machinery, and machinery and equipment less demanding torque uniformity. 1. The displacement of the hydraulic motor, the displacement and torque relationship The output torque of the hydraulic motor working in size is determined by the load torque. However, to promote the same size of the load, the working cavity of the pressure of the motor is lower than the pressure of the working cavity small motor, so that the size of the working cavity is an important symbol of the hydraulic motor ability to work. Representation of the size of the working cavity of the hydraulic motor and the hydraulic pump, which means that CC V. The displacement of the hydraulic motor is an important parameter. Can be calculated at a given pressure, the size of the hydraulic motor can output torque, the size of the working pressure under a given load torque motor may also be calculated according to the size of the CC. When the hydraulic motor into the pressure difference between the oil outlet for the input of the hydraulic motor flow rate q, the theoretical torque of the hydraulic motor output, the angular velocity, if not taking into account the loss of hydraulic hydraulic pump output power should be all converted to hydraulic the mechanical power of the motor output, i.e. Because, so the theoretical torque of the hydraulic motor 2. The mechanical efficiency of the hydraulic motor and start the mechanical efficiency Hydraulic motor internal inevitably the presence of a variety of friction, the actual output torque than the theoretical torque smaller, i.e. Where the mechanical efficiency of the hydraulic motor. In addition, under the same pressure, the output torque of the hydraulic motor begins to turn from rest to start-up state torque than the operating load to the hydraulic motor to start the cause difficulties, so the start-up performance of the hydraulic motor is very important. The starting torque is reduced because the maximum coefficient of friction in a stationary state, appears on the friction surface the relative sliding coefficient of friction is significantly reduced, which is the general nature of the mechanical friction. Hydraulic motor, the stationary state lubricant film is squeezed out, basically becomes dry friction. And the motor begins to move, with the establishment of the lubricant film, friction immediately drop and reduced increases with the sliding velocity and film thickening. Hydraulic motor start-up performance indicators start mechanical efficiency, which was expressed as wherein the starting torque of the hydraulic motor. Different types of hydraulic motors, internal force components of the force balance is different, the size of the friction, and so are not the same. The same type of hydraulic motor, the force of friction pair balanced design, its high and low points. For example, some gear-type hydraulic motor only about 0.6, and the high-performance low-speed high torque hydraulic motor can be achieved = 0.90, vary considerably. So, if the hydraulic motor load start, it must be noted that the start-up performance of the selected hydraulic motor. 3. Hydraulic motor speed and low-speed stability The rotational speed of the hydraulic motor vary depending on the displacement V of the liquid supply flow rate q, and the hydraulic motor itself. Since the hydraulic motor internal leakage, not all the liquid into the motor driving the hydraulic motor acting, a small portion of the liquid is lost due to leakage losses, so the actual motor speed than Ideally low. wherein the volumetric efficiency of the hydraulic motor. In engineering practice, the speed of the hydraulic motor and hydraulic pump speed, measured in units of multi-purpose r / min (r / min). When the operating speed of the hydraulic motor is too low, often to maintain not uniform speed, the unstable state of the dynamic stop, which is called creeping phenomenon. Require high-speed hydraulic motor does not exceed the to 10r/min low speed high torque hydraulic motor does not exceed speed work of 3r/min, not all of the hydraulic motor can meet the requirements of. Generally speaking, low speed - low-speed torque hydraulic motor stability than the high-speed motor as well. The large displacement of the low speed high torque motor, and thus the size is large, and not caused by too low even at low speeds the sliding speed of the friction pairs, coupled with the motor displacement, the effect of leakage is relatively small, the moment of inertia of the motor itself, , so easy to get good low-speed stability return to the main directory 4 .Speed range When the work load within a very wide range from low speed to high speed, the hydraulic motor is also required to be able to work under a large speed range, or need to be able to shift the transmission mechanism, the transmission mechanism is complicated. Hydraulic motor speed range to allow maximum speed and minimum steady speed ratio, Obviously, the wide range of speed hydraulic motor should be both good high-speed performance and a good low-speed stability.The hydraulic cylinder of the hydraulic pump output pressure can be converted to mechanical energy of the actuator, it is mainly used to output the linear motion (oscillating motion). Classification of a hydraulic cylinder Hydraulic cylinder according to the structure can be divided into three categories of the piston cylinder, piston-cylinder and swing cylinder. Piston cylinder and piston-cylinder reciprocating motion, the output thrust and speed, swing cylinder is able to swing back and forth less than 360 degrees, the output torque and angular velocity. In addition to the use of a single hydraulic cylinder can also several combination or in combination with other bodies, to complete a special function. (A) piston hydraulic cylinder Piston hydraulic cylinder is divided into a double rod and single-rod two. 1 double rod piston cylinder Double rod piston cylinder piston on both ends of a diameter equal to extend the piston rod, depending on the installation can be divided into two fixed fixed cylinder and piston rod. Figure 3-4a as shown in double-rod fixed to the cylinder tube piston cylinder. The inlet and the outlet port arranged at both ends of the cylinder, piston driven by the piston rod table moves, when the effective stroke of the piston l, the range of motion of the whole table to 3L, machine covers an area of generally applicable small machine. Table travel requires a longer, can be shown in Figure 3-4B piston rod fixed form, then the cylinder block and the table is connected to the piston rod through the bracket on the machine, the power came by the cylinder. This form of installation, the range of movement of the table is only equal to the hydraulic cylinder effectively double the stroke length l (2L), and therefore small footprint. Out of the oil port can be set in the hollow stationary - the ends of the piston rod, the oil from the piston rod and out, can also be set at both ends of the cylinder, but must use the hose connection. Due to the double pole at both ends of the piston cylinders piston rod diameter is usually equal, so it is left, the effective area of the right two chambers are equal. When the left, right cavity enter the same pressure and the same fluid flow, the hydraulic cylinder both left and right direction of thrust and speed equal to the feed of the hydraulic cylinder when the piston diameter D, the piston rod diameter d, oil chamber pressures p1 and p2, q when the input flow, the double-rod cylinder-piston thrust force F and the velocity v Where A is the effective working area of the piston.In operation, the double-rod cylinder-piston design into a piston rod is subject to a pull, and the other piston rod is unstressed, the piston rod of the hydraulic cylinder can be made thin. (B) piston-cylinder The piston-cylinder is a single-acting hydraulic cylinder, its working principle is shown in Figure 3-7a shown, the plunger connected with the working parts, the cylinder is fixed on the body. When the pressure oil into the cylinder, push the plunger to drive the moving parts moving to the right, but the reverse return must rely on other external forces or weight-driven. Usually used in pairs of piston-cylinder reverse arrangement, as shown in Figure 3-7b. When the thrust F generated on the plunger when the plunger diameter d, the the input hydraulic oil flow q, pressure p and speed v The main features of the plunger hydraulic cylinder piston and cylinder with the requirements inside the cylinder hole without finishing even without processing. Oriented movement by the guide sleeve in the cylinder head, so it is especially suitable to the occasion of the trip is longer. C) swing cylinder Swing hydraulic cylinder, also known as swing hydraulic motor. When it Walter pressure oil, the spindle can be less than the output oscillating motion, and Top Jigs clamping means, the feed device, transfer device and the need to periodically feed system. Figure 3-8a shows a single-vane rotary actuators, the swing angle, up to. When the the swing cylinder oil inlet and outlet pressure p1 and p2, the input flow q, its output torque T and angular velocity of the Formula, b is the width of the blade, R1, R2 for the bottom of the blade, at the top of the radius of gyration.中文部分：液压执行元件是将液压泵提供的液压能转变为机械能的能量转换装置，它包括液压缸和液压马达。液压马达习惯上是指输出旋转运动的液压执行元件，而把输出直线运动(其中包括输出摆动运动)的液压执行元件称为液压缸。一、液压马达的特点及分类从能量转换的观点来看，液压泵与液压马达是可逆工作的液压元件，向任何一种液压泵输入工作液体，都可使其变成液压马达工况；反之，当液压马达的主轴由外力矩驱动旋转时，也可变为液压泵工况。因为它们具有同样的基本结构要素-密闭而又可以周期变化的容积和相应的配油机构。但是，由于液压马达和液压泵的工作条件不同，对它们的性能要求也不一样，所以同类型的液压马达和液压泵之间，仍存在许多差别。首先液压马达应能够正、反转，因而要求其内部结构对称；液压马达的转速范围需要足够大，特别对它的最低稳定转速有一定的要求。因此，它通常都采用滚动轴承或静压滑动轴承；其次液压马达由于在输入压力油条件下工作，因而不必具备自吸能力，但需要一定的初始密封性，才能提供必要的起动转矩。由于存在着这些差别，使得液压马达和液压泵在结构上比较相似，但不能可逆工作。液压马达按其结梅类型来分可以分为齿轮式、叶片式、柱塞式和其它型式。按液压马达的额定转速分为高速和低速两大类。额定转速高于500rmin的属于高速液压马达，额定转速低于500rmin的属于低速液压马达。高速液压马达的基本型式有齿轮式、螺杆式、叶片式和轴向柱塞式等。它们的主要特点是转速较高、转动惯量小，便于启动和制动，调节(调速及换向)灵敏度高。通常高速液压马达输出转矩不大(仅几十Nm到几百Nm)所以又称为高速小转矩液压马达。低速液压马达的基本型式是径向柱塞式，此外在轴向柱塞式、叶片式和齿轮式中也有低速的结构型式，低速液压马达的主要特点是排量大、体积大转速低(有时可达每分钟几转甚至零点几转)，因此可直接与工作机构连接，不需要减速装置，使传动机构大为简化，通常低速液压马达输出转矩较大(可达几千Nm到几万Nm)，所以又称为低速大转矩液压马达。二、液压马达的工作原理 1.叶片式液压马达由于压力油作用，受力不平衡使转子产生转矩。叶片式液压马达的输出转矩与液压马达的排量和液压马达进出油口之间的压力差有关，其转速由输入液压马达的流量大小来决定。由于液压马达一般都要求能正反转，所以叶片式液压马达的叶片要径向放置。为了使叶片根部始终通有压力油，在回、压油腔通人叶片根部的通路上应设置单向阀，为了确保叶片式液压马达在压力油通人后能正常启动，必须使叶片顶部和定子内表面紧密接触，以保证良好的密封，因此在叶片根部应设置预紧弹簧。叶片式液压马达体积小，转动惯量小，动作灵敏，可适用于换向频率较高的场合，但泄漏量较大，低速工作时不稳定。因此叶片式液压马达一般用于转速高、转矩小和动作要求灵敏的场合。 2.径向柱塞式液压马达图3-2为径向柱塞式液压马达工作原理图，当压力油经固定的配油轴4的窗口进入缸体3内柱塞1的底部时，柱塞向外伸出，紧紧顶住定子2的内壁，由于定子与缸体存在一偏心距。在柱塞与定子接处，定子对柱塞的反作用力为。力可分解为和两个分力。当作用在柱塞底部的油液压力为，柱塞直径为，力和之间的夹角为时，它们分别为力对缸体产生一转矩，使缸体旋转。缸体再通过端面连接的传动轴向外输出转矩和转速。以上分析的一个柱塞产生转矩的情况，由于在压油区作用有好几个柱塞，在这些柱塞上所产生的转矩都使缸体旋转，并输出转矩。径向柱塞液压马达多用于低速大转矩的情况下。 3.轴向柱塞马达轴向柱塞泵除阀式配流外，其它形式原则上都可以作为液压马达用，即轴向柱塞泵和轴向柱塞马达是可逆的。轴向柱塞马达的工作原理如图所示，配油盘4和斜盘1固定不动，马达轴5与缸体2相连接一起旋转。当压力油经配油盘的窗口进入缸体的柱塞孔时，柱塞在压力油作用下外伸，紧贴斜盘斜盘1对柱塞产生一个法向反力，此力可分解为轴向分力及和垂直分力凡。凡与柱塞上液压力相平衡，而凡则使柱塞对缸体中心产生一个转矩，带动马达轴逆时针方向旋转。轴向柱塞马达产生的瞬时总转矩是脉动的。若改变马达压力油输入方向，则马达轴按顺时针方向旋转。斜盘倾角的改变、即排量的变化，不仅影响马达的转矩，而且影响它的转速和转向。斜盘倾角越大，产生转矩越大，转速越低。 4齿轮液压马达齿轮马达在结构上为了适应正反转要求，进出油口相等、具有对称性、有单独外泄油口将轴承部分的泄漏油引出壳体外；为了减少启动摩擦力矩，采用滚动轴承；为了减少转矩脉动齿轮液压马达的齿数比泵的齿数要多。齿轮液压马达由干密封性差，容租效率较低，输入油压力不能过高，不能产生较大转矩。并且瞬间转速和转矩随着啮合点的位置变化而变化，因此齿轮液压马达仅适合于高

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