# 05液压系统Hydraulic system.pdf

October 6, 2017 | Author: George Jhonson | Category: Pump, Valve, Fluid Dynamics, Gases, Hydraulics

#### Short Description

LiuGong CLG92XX Hydraulic System...

#### Description

1.1 帕斯卡原理 Pascal’s theorem 1. 处于密闭容器内的液体对施加于它表 面的压力向各个方向等值传递。 Pressure on a confined liquid will exert the same force in all directions equally .

Large area

2.速度的传递按“容积变化相等”的原则 The speed of the load, as it moves, is in direct proportion to the area of it’s cylinder verses the area of the cylinder F. 3.液体的压力由外载荷建立。认为泵一出 油就有压力是错误的。 Fluid pressure is created by external load. No load, no pressure. 4.能量守恒 Conservation of energy

Small area F

Full of oil

F＝p×A P＝v×F

v＝q÷A

F--force p--pressure A--area q--flow P--power v--speed

1.2 液压系统常用线型和符号 Lines and symbols commonly used in hydraulic systems 线型 Lines: 粗实线表示工作管路 Thick solid lines represent work lines 虚线表示控制管路 Broken solid lines represent pilot or drain lines 双点划线表示组合元件 Double dotted lines represent combined elements 有小圆点的相交线表示连接管路 Intersect lines with small dots represent connected lines. 有小圆弧的相交线表示不相交连接管路 Intersecting lines with small circular offset, represent lines or circuits that do not meet

1.3 液压系统的基本构成 Basic composition of the hydraulic system 液压系统由4部分组成： Hydraulic system consist of 4 parts: 液压泵：将机械能转换为液体压力能。 Hydraulic pump: Converts the mechanical energy to hydraulic energy. 执行元件：将液体压力能转换为机械能。例 如油缸、油马达等。 Implement components: Convert the hydraulic energy to mechanical energy. For example cylinder, motor and so on.

1.3 液压系统的基本构成 Basic composition of the hydraulic system 控制元件：各种阀。大致有压力控制阀、流 量控制阀、方向控制阀等。 Control components: Valves. Generally, there are pressure control valves, flow control valves, directional control valve. 辅助元件：油箱、过滤器、管路、接头、密 封、冷却器、蓄能器等等。 Auxiliary components: Hydraulic tank, filters, piping, joints, seals, coolers, accumulators and so on.

1.4 液压元件符号 Symbol of hydraulic components 液压泵 Hydraulic pump:

1.4 液压元件符号 Symbol of hydraulic components 液压阀 Hydraulic valves :

1.4 液压元件符号 Symbol of hydraulic components 液压马达 Hydraulic motor:

1.4 液压元件符号 Symbol of hydraulic components 液压缸 Hydraulic cylinder :

A

B

A

B

1.4 液压元件符号 Symbol of hydraulic components 辅助元件 Auxiliary components:

1.5 推荐用液压油 Recommended Hydraulic oil

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.1 主泵 (描述) Main pump (description) 该泵由主泵和先导泵构成。主泵是可变排量轴向柱塞泵，他提供高压油给 液压系统。先导泵是定排量齿轮泵，它给控制系统提供先导油。主泵由发动机 通过联轴器驱动，先导泵与主泵的轴直接连接，转速和主泵一致。 This pump is composed of main pump and pilot pump. The main pump is a variable displacement axial plunger pump. It provides high pressure oil for the hydraulic system of excavator. The pilot pump is a fixed displacement gear pump. It supplies oil for the control system. The main pump is driven by the engine through a coupler. The pilot gear pump is connected directly by the drive shaft of the main pump at the same rotate speed.

2.1 主泵 (主要参数) Main pump (main parameters) 条目 Item

923D/925D

Duplex Variable Axial Piston Pump

Duplex Variable Axial Piston Pump

cc

108

115

L/min

2×215

2×230

MPa

34.3

34.3

Gear pump

Gear pump

920D/922D

cc

10

10

L/min

20

20

MPa

3.9

3.9

2.1 主泵(外形) Main pump (shape) 先导泵测压口 The port of pilot pressure test

2.1 主泵(液压回路图) Main pump (Hydraulic schematic ) P1泵调节器 Regulator for P1 pump

P2泵调节器 Regulator for P2 pump

Pilot pump P1 pump P2 pump

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.2 主控阀(描述) Main control valve (description) 主控阀位于主泵和执行元件（油缸和马达）之间，它控制执行元件的油的 方向和流量。控制阀为液压先导控制、开式负流量控制阀，由九个阀芯组成、 并联的整体式多路换向阀。包含用于控制动臂、斗杆、铲斗、回转、行走、附 属装置的阀芯。控制阀具有动臂上升合流、斗杆合流、斗杆再生、回转优先、 动臂、斗杆锁定、直线行走等功能。 The main control valve is located between the main pump and actuators(all of the cylinders and motors).It controls the oil direction, pressure, and flow rate for all of the actuators. Main control valve is pilot control, open negative flow control, and paralleling monolithic multi-ported directional valve composed of nine spools. It includes spools for the boom，arm，bucket， swing，travel and auxiliary devices. Main control valve has the auxiliary functions for boom raise confluence，arm confluence，arm regeneration， swing priority，boom anti-drift，arm anti-drift and straight travel.

2.2 主控阀(主要参数) Main control valve (main parameters) 条目 Item

920D/922D

923D/925D

Mpa

31.8

32.2

Mpa

33.3

34.6

Mpa

25.5

25.5

2.2 主控阀(外形) Main control valve (Shape) 斗杆油口溢流阀 Port relief valve for arm spool

2.2 主控阀(外形) Main control valve (Shape) C2

HV

HV

C1

920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

CP2 负反馈 油口FR 负反馈 油口FL

CSp

CSp

2.2 主控阀(液压回路图) Main control valve (Hydraulic schematic )

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.3 回转马达及减速机(描述) Swing motor & reduction gear (description) 回转马达及减速机由液压马达和减速机组成。它带动挖掘机的上 部机构回转。 The swing motor&reducer consists of a hydraulic motor and a reduction gear.It rotates the upper structure of excavator.

920D/922D

923D/925D

2.3 回转马达及减速机(外形) Swing motor & reduction gear (shape) 润滑油加注口 Port for lubricating oil

2.3 回转马达及减速机(外形) Swing motor & reduction gear (shape)

2.3 回转马达及减速机(液压回路图)

Swing motor & reduction gear (hydraulic schematic)

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.4 行走马达及减速机(描述) Travel motor & reduction gear (description) 行走马达及减速机由液压马达和减速机组成。它带动挖掘机的上 部机构回转。它用来控制机器向前、向后、左转、右转运动。行 走速度由行走速度控制开关控制。它有两档速度：低速和高速。 它不能从高速档自动调到低速档。 The Travel motor & reducer consists of a hydraulic motor and a reduction gear. It is used to control the forward, backward, left turn and right turn operation of the machine.The travel speed can be controled by travel speed control switch.There are two speed positons:Low Speed and High Speed. It does not automatically downshift.

2.4 行走马达及减速机(外形) Travel motor & reduction gear (Shape)

2.4 行走马达及减速机(液压回路图) Travel motor & reduction gear (hydraulic schematic )

920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.5 手先导阀(描述) Pilot valve (description) 手先导阀用于控制执行元件的速度和操作。一个位于驾驶室内座 椅左侧，一个位于右侧。在标准模式下，左侧先导阀控制回转、 斗杆和喇叭，右侧先导阀控制动臂、铲斗和增压。 The pilot control valve is used to control implements speed and operation. One is installed on the left side of operator seat in the cab, and another is installed on the right side. The left one controls swing, arm and horn. The right one controls boom and bucket and power boost in standard mode.

2.5 手先导阀(液压回路图) Pilot valve (Hydraulic schematic )

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.6 行走先导阀(描述) Travel pilot valve (Description) 行走先导阀提供先导油至主控阀上的行走阀芯，控制整机前进、 后退、左转、右转。它也能控制行走系统平稳的运行。 The travel pilot valve supplies pilot oil for the travel spools of the main control valve to control the forward, backward, left turn and right turn operation of the machine. It also has hydraulic dampeners to smooth operation of the travel system.

2.6 行走先导阀(液压回路图) Travel pilot valve (Hydraulic schematic )

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.7 先导阀块(描述) Pilot valve block (description)

2.7 先导阀块(液压回路图) Pilot valve block (Hydraulic schematic )

z

3.挖掘机液压系统 Hydraulic system of excavator

§ 3.1 液压系统参数 Hydraulic system parameters § 3.2 液压系统传动简图 Drive diagram of hydraulic system § 3.3 液压系统回路图 Hydraulic system schematic 3.3.1 负流量控制系统 Negative flow control system 3.3.2 动臂上升 Boom raise 3.3.3 动臂下降 Boom lower 3.3.4 斗杆伸 Arm out 3.3.5 斗杆收 (带再生功能) Arm In (with regeneration) 3.3.6 斗杆收 (不带再生功能) Arm In (without regeneration) 3.3.7 铲斗伸 Bucket in 3.3.8 铲斗收 Bucket out 3.3.9 左回转 Swing left 3.3.10 右回转 Swing right 3.3.11 前进(高速) Forward travel (high speed) 3.3.12 后退( 低速) Backward travel (low speed) 3.3.13 直线行走 Straight travel

§ 3.1 液压系统参数 Hydraulic system parameters 条目 Item

920D/922D

923D/925D

Double Variable Axial Piston Pump

Double Variable Axial Piston Pump

cc

108

115

1

2

3

L/min

2×215

2×230

4

MPa

31.8

32.2

5

MPa

33.3

34.6

6

MPa

25.5

25.5

7

MPa

31.8

31.8

8

MPa

36.3/36.3

36.6/36.6

9

MPa

37.2/37.2

36.6/37.2

10

MPa

35.3/36.3

36.6/37.2

11

Mpa

19.6

19.6

§ 3.1 液压系统参数 Hydraulic system parameters 12

13

cc

10

10

14

L/min

20

20

15

MPa

3.9

3.9

16

mm

120×85×1187-1794

φ125×φ90×1350×1950

17

mm

135×95×1450-2063

φ140×φ105×1610×223 5

18

mm

120×85×1058-1593

φ130×φ90×1075×1665

19

L

230/330

230/330

20

L

3.4

4.4

21

L

5.5*2

5.5*2

§ 3.2 液压系统传动简图 Drive diagram of hydraulic system 驱动 柴油机

Drive

Control oil

Pilot pump

Engine

Work oil

Work pump

Implement work

Control

Carry out

Motor

Work oil

Carry out

Cylinder

Swing、Travel

3.3 液压系统回路图 Hydraulic system schematic 3

3.3.1 负流量控制系统 Negative Flow Control System

BOOM RAISE 3.3.2 动臂上升Boom Raise

BOOM LOWER 3.3.3 动臂下降Boom Lower

ARM OUT

3.3.4 斗杆伸Arm Out

ARM IN WITH REGENERATION

3.3.5 斗杆收(带再生功能)Arm In (With Regeneration)

3.3.6 斗杆收(不带再生功能) WITHOUT ArmARMREGENERATION InIN(Without Regeneration)

BUCKET IN 3.3.7 铲斗收 Bucket In

3.3.8 BUCKET 铲斗伸Bucket Out OUT

M

SWING LEFT 3.3.9 左回转Swing Left

3.3.10右回转Swing SWING RIGHT Right

3.3.11 前进(高速) Forward Travel (High Speed) FORWARD TRAVLE(HIGH SPEED)

3.3.12 后退(低速) Backward Travel (Low Speed) BACKWARD TRAVLE(LOW SPEED)

3.3.13 直线行走Straight Travel STRAIGHT TRAVLE

4.1 主泵管路 Main pump piping 泄油管Case Drain hose

4.2 回转马达管路 Swing Motor Piping

4.2 回转马达管路 Swing Motor Piping 泄油管 Case Drain hose

4.3 先导液压管路(先导阀块)

Pilot hydraulic pipe line(Pilot valve block)

4.3 先导液压管路(先导阀块)

Pilot hydraulic pipe line(Pilot valve block)

920D(Ⅱ)、 922D(Ⅱ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

5.1 系统压力测试 System pressure test P2

P1

a2

a1

P1、P2口压力测试:(压力测试口a1、a2 ,规格：G1/4) Port P1、P2 pressure test:(pressure test ports a1、a2 dimension:G1/4) 1、用扳手拧开图中a1、a2处的螺塞并连上测压接头和压力表(压 力表量程0～70MPa)； Remove the plug a1/a2 in the illustration with a spanner and connects with a pressure testing joint and a pressure gauge(with a range of 0~70MPa); 2、启动发动机，慢慢的操作挖掘机使油温增高到50±5℃左 右，然后读压力表的读数； Start engine, Slowly operate the excavator to raise the hydraulic oil temoerature to 50±5℃;then read the data from the gauge; 3、拧下压力表和测压接头，用16Nm的扭矩拧紧螺塞。 Remove pressure gauge and pressure testing joint.Tighten the plugs to a torque of 16Nm.

1、启动发动机，缓慢提高发动机转速到最高转速； Start the engine, increase it‘s rotating speed slowly to full speed ； 2、调整挖掘机上的显示器功能，使之位于检测左泵和右泵压力的状态 ； Set the excavator monitor to the function of cheking the left and right pump pressure; 3、放下先导操作手柄，操作工作装置使液压油温升高到50±5℃，然后操作动臂或斗杆伸出到行程 末端位置，使安全阀打开。此时的压力值应为31.8~32.8MPa，再按下位于右操作杆上的按钮，压力 值应为33.3~34.3MPa； Turn on the pilot cutoff lever, operate the work implements to let the hydraulic oil temperature raises to 50±5℃, then operate the boom up or arm to extreme position to make the main relief valve open. At the moment the pressure value should be 31.8~32.8MPa, then press the burst button located on the right joystick, the pressure value should be 33.3~34.3MPa； 4、如果压力值不在以上的范围之内，我们需要按照以下的步骤进行调整： If the pressure values are not in the arrange above, we need to adjust them as following procedure: (1) 用开口为30mm的开口扳手松开序号3锁紧螺母； Loose locknut number 3 with open-end wrench(30mm);

(2) 按下右操作杆上的按钮，用6mm的内六角扳手向内或向外旋转序号4零件，同时观察显示器上的 压力值，当达到33.3-34.3MPa时，停止旋转序号4零件并拧紧序号3零件，松开右操作杆上的按钮； Press the burst button located on the right joystick ，turn number 4 slightly inwards or outwards slowly with inner hexagon spanner(6mm) and check the pressure value in the monitor.Stop turning number 4 when the pressure value reaches to 33.3-34.3MPa, then tighten number 3， loose the burst button located on the right joystick ; (3)用开口为22mm的开口扳手逆时针松开序号5锁紧螺母，用6mm的内六角扳手向内或向外旋转序号 4零件，同时观察显示器上的压力值，当达到31.8-32.8MPa时，停止旋转序号4零件并拧紧序号5零 件。 Loose locknut number 5 with open-end wrench(22mm) in anticlockwise direction.Turn number 4 inwards or outwards slowly with hexagon spanner(6mm) and check the pressure value in the monitor. Stop turning number 4 and tighten number 5 when the pressure value reaches to 31.8~32.8MPa. 主安全阀 Main relief valve

5.3 先导压力测试 Pilot pressure test

3、在发动机转速在最高转速时，看压力表的读数，数值应 在3.9~4.1MPa之间。 Set the engine speed to full speed , check the pressure gauge,the value should be between 3.9~4.1MPa.

5.3 先导压力测试 Pilot pressure test

1、用手拧开图中序号2或序号4处的螺塞并连上压力表(压力表量 程0～6MPa); Remove the plug number 2 or 4 in the illustration by hand and connects with a pressure gauge(with a range of 0~6MPa); 2、启动发动机，慢慢的操作挖掘机使油温增高到50±5℃左右， 然后读压力表的读数； Start engine, Slowly operate the excavator to raise the hydraulic oil temperature to 50±5℃; 3、在发动机转速在最高转速时，看压力表的读数，数值应在 3.9~4.1MPa之间。 Set the engine speed to full speed, check the pressure gauge,the value should be between 3.9~4.1MPa.

(2)、拧下压力表和测压接头，用16Nm的扭矩拧紧螺塞。 Remove pressure gauge and pressure testing joint. Tighten the plug to a torque of 16Nm.

5.4 先导压力调整 Pilot pressure adjust 先导溢流阀 Pilot relief valve

6.1 液压元件动作缓慢 Hydraulic components works slowly 原因 Cause

1

2

3

4

5

6

7

6.2 液压油过热 Hydraulic oil over hot 原因 Cause

1

2

3

4

5

6

7

8

6.3 低压或无油压 Low pressure or no oil pres-sure 原因 Cause

1

2

3

4

5

6.4 液压缸工作但不能提升载荷 Cylinder can work but can not lift load 原因 Cause

1

2

3

4

5

6.5 一个控制操作杆不工作 One control lever does not work 原因 Cause

1

2

3

4

5

6

6.6 一个液压缸不工作 One cylinder does not work 原因 Cause

1

2

3

4

5

6

6.7 一个行走马达不工作 One travel motor does not work 原因 Cause

1

2

3

4

5

Replace and repair worn parts of travel motor or clean it

Repair or replace worn parts of travel pilot valve or clean it 修理或更换 Repair or replace

6.8 不能回转 Can not swing

1

2

3