CAT液压内部培训教程(ppt 117页)

主要内容
Objectives 目标
Power Flow 动力流动
Energy Distribution during Truckloading 9XX 9XX 装车应用时的能量分配
Focus Primary users of energy 焦点能量的主要使用者
Implement System 工作系统
Terminology
Hydraulic Schematics
Tandem Center Valve(Open Center at Cat)
627 G – Implement SystemTandem Center – Interrupted Series
980H Implement Schematic Tandem Center (open) Interrupted Series
988H Implement SchematicTandem (Open) Center Interrupted Series
Tandem (Open) Center System
Tandem (Open) Center Hydraulic System开芯式液压系统
Valve Hardware阀硬件
988H Tilt Stem Characteristics
988H Lift Stem Characteristics
Pump Hardware Gear Pump
Pump HardwareVane Pump
Pump HardwarePiston Pump
WHERE
Examine actual machine装载机现场调查
Work at Board 白板展示
Speed ControlFill in chart for a light load and a heavy load速度控制完成轻载及重载图表
Force Control Fill in chart for a light load and a heavy load力的控制完成轻载及重载图表
Basic Hydraulic Equations 基本液压公式
Basic Force Equations 基本的力的计算公式
Basic Force Equations for hydraulic components 液压件的基本力的计算公式
Summary
Form small teams to work problemsNeed to stagger groups to work on machine tests分成小组解决问题需要交叉小组进行整车测试
Fundamentals – Open Center SystemsExercise 基础知识-开芯式系统练习
Fundamentals – Open Center Systems基础知识-开芯式系统
Machine Tests整车测试
Machine Tests 整车测试
Load Sensing 加载敏感的
Efficiency 效率
Modifications to go from Open Center Hydraulic System toClosed Center Hydraulic System开芯式系统到闭芯式系统的变更
Pump Controls – High Pressure Cut Off泵控制-高压截止
High Pressure Cut Off 高压截止
Pump Controls – Load Sensing泵控制 – 负载敏感的
Load Sensing Control 载荷敏感控制
Physical Locations of Controls
Vickers Load Sensing Compensator and Pressure Limiter
Sample System
System in Neutral
Variable Pump – Neutral ModeLoad Sensing Spool MetersPump  near 0 – has sufficient flow to compensate for leakage and maintain output = margin
System Actuated
Variable Pump – Actuated Mode Load Sensing Spool MetersPump  at displacement  needed to provide sufficient flow to  maintain pressure drop from pump to signal (cylinder)  output pressure = margin plus cylinder
System at High Pressure Cut
Variable Pump – Pressure Limit Mode Pressure Cut off Spool MetersPump  near 0 – has sufficient flow to compensate for leakage and maintain output = high pressure cut pressure
Pump Controls627H Tier 4 Interim
Pump Controls – 980H InterimPump Discharge sent to control piston
Pump Controls – 988H Electronic Pump Control – no signal pressure Pilot Pressure sent to control spool
How do we generate the loadsensing signal?
Signal Generation 信号的产生
Work at White Board
627 Tier 4H Interim
980 Closed Center ValveParallel Circuit
Fundamentals – Closed Center Systems基础知识-闭芯式系统
Pressure Compensation
980H Interim Closed Center LS - Post CompensationValves in Neutral
980H Interim Closed Center LS - Post CompensationShifted Valves
MG  Closed Center LS - Post CompensationValves in Neutral
MG  Closed Center LS - Post CompensationValve Shifted
Load Cases
980H Interim Closed Center LS - Post CompensationCase 1 Demand 100 lpm in both circuits
980H Interim Closed Center LS - Post CompensationCase 2 Demand 200 lpm in both circuits
980H Interim Closed Center LS - Post CompensationCase 3 Demand 100 lpm in both circuits
980H Interim Closed Center LS - Post CompensationCase 4 Demand 200 lpm in both circuits
980H Interim Closed Center LS - Post CompensationCase 5 Demand 100 lpm in both circuits, one circuit stalled, one resistive
980H Interim Closed Center LS - Post CompensationCase 6 Demand 100 lpm in both circuits, one circuit stalled, one overrunning
What is Pressure Compensation and What are the Advantages?
Proportional Priority Pressure Compensationor Post Pressure Compensation
Closed Center LS - Post Compensation
Fundamentals – Pressure Compensation基础知识-闭芯式系统 Needs edited
Ride Control System
Simplest Ride Control
Additional valving for ride control
Equations
Fundamentals – Ride Control

..............................