Swain - Eb723pdf

Fluid Power (System Design Concepts)

© Actrac Products Ltd/ Australian National Training Authority 1997 1

MODULE TITLE FLUID POWER (SYSTEM DESIGNCONCEPTS)

Nominal Duration One Module

Module Code or Number EB 723

Purpose This module aims to allow the students to producea feasibility study for a fluid power system using acombination of hydraulic, pneumatic andPLC/electrical/electronic areas of study.

Relationship toCompetency Standards This module will be modified in line with the

requirements of the National Metals andEngineering Standards when they becomeavailable.

The module contains the knowledge and skillsidentified and agreed by all state/territories. Ithas been developed on the assumption that thesewill be reflected in the Standards.

Prerequisites NM59 Hydraulics 4NM62 Pneumatics 4NM63 Control 3

Summary of Content

1. Specification

1.1 Final product1.2 Machine Needs Forces and torques

SpeedsAccuracyTypes of load

1.3 SafetyTypes of loadLoad in relation to peopleGuardingInterlockingLoad control


2 © Actrac Products Ltd/ Australian National Training Authority 1997

1.4 Type of controlPLC, electrical, pneumatic, hydraulicAutomaticManual

1.5 LifeNumber of cycles per yearNumber of cycles totalMaintenance time availableAllowance for downtime

1.6 Reliability1.7 Services available

Electric power3 PhaseSingle Phase

Compressed airWater and air

CoolingSize of locationAccessLifting equipmentCommunication systems

1.8 EnvironmentTemperatureHumidityHazardsContamination

DustChemicalFlammable liquidsFlammable gases or vapours

Acceptable noise levelsOil leaks

1.9 StandardsAS3900AS standards in fluid powerLocal standardsDLI, OH & S



2. Mechanical calculations

2.1 Identify worst conditions2.2 Components of forces

Horizontal and vertical components2.3 Acceleration and deceleration2.4 Friction2.5 Winch drives

Line pullLine speedEffective radius

2.6 Vehicle drivesRolling resistanceGrade resistanceDrawbar pullRolling radius

2.7 Gear, chain and belt drives Ratios

Efficienciesself locking gearboxes

3. Design philosophy

3.1 Pressure selection3.2 Quality of components3.3 Lubrication or non lubricated pneumatics3.4 Maintenance3.5 Cost

4. Initial design

4.1 Pressure, force, area4.2 Area, speed, flow rate4.3 Pressure, flow rate, power4.4 Air consumption

5. Comparison of methods

5.1 High - low5.2 Regenerative5.3 Accumulator5.4 Single pump5.5 Multi pump5.6 Kicker cylinder



6. Optimising

6.1 Reduce flows, pressures and powers6.2 Change the design parameters6.3 Change times6.4 Compromise

7. Control requirements

7.1 Position7.2 Force and torque7.3 Speed7.4 Acceleration/deceleration7.5 Constant power7.6 Decompression7.7 Documentation

Solenoid chartsPLC logic statements

Delivery This module draws on the calculations and designcarried out in previous hydraulic and pneumaticsubjects.

Instructions will be required in the fields ofdetermining the system specification; advancedcalculations and system control; optimising andsummarising the results.

It is suggested that this subject be carried outimmediately preceding Fluid Power (ComponentSelection and Sizing For Design), and that thedesign project be a combination of the twosubjects.

The design project for this subject will require aspecified system using a combination of hydraulic,pneumatic and PLC/electrical/electronic complexwhich interact with each other and to besufficiently complex to require a detailed analysis.This includes:

High forces and torquesHigh speedsAccurate control requirementsInteraction between some of the functions and the quality of the manufactured product.



A new design project will need to be set yearly. Itis suggested that all participating TAFE collegesagree to a roster for setting the design project forall states each year, to ensure that a nationalstandard is set and adhered to.

The design project will need to cover as wide arange of design criteria as possible, However, itmust be recognised that all of the topics detailedin the outlines cannot be covered in a realisticsystem.

The system will need to address the importantsafety, end user and local environment needs toenable a practical system to be designed.

Learning outcomes On completion of this module the learner will beable to:

Learning Outcome 1 Write a specification for acomplete manufacturing system to enablethe design for the system to be carried out,taking into account all variables which willeffect the design.

Assessment criteria Identify the details of the final product which willeffect the system design.

Identify the customer requirements in terms ofcost, life of machine, safety, type of control anddetails of the proposed location of the system,which need to be considered when designing thesystem.

Conditions

Assessment methods Written summary of parameters which willbe considered during the writing of thespecification.



Learning Outcome 2 Calculate the actuator forces and torquesover the whole speed range from themechanical specification, taking intoaccount the machine variables.

Assessment criteria Identify the mechanical variables which mustbe considered in the design.

Calculate the acceleration and deceleration,friction, components of forces and moments of

forces.

Calculate the ratios and efficiencies of anymechanical drives in the design.

Calculate the actuator forces and speeds.

Conditions

Assessment methods Written answer test of a mechanical designinvolving friction, components of forces andmoments of forces.

Learning Outcome 3 Choose the design parameters to suit therequirements of the end user, related to thespecification for the system.

Assessment criteria Use manufacturers catalogues to select the qualityof components to be used and the workingpressures in relation to the rated pressures, toallow the design to meet the cost reliability andlife requirements of the system.

Conditions

Assessment methods Brief written preliminary report stating thereasons for making the selections.



Learning Outcome 4 Calculate the actuator sizes, pressures, flowrates, and powers for the system, based onthe system specification and thedesign parameters.

Assessment criteria Calculate the actuators, sizes using forces ortorques and working pressures.

Select the actuators, using standard sizes frommanufacturers catalogues

Recalculate the maximum working pressure foreach actuator selected.

Calculate the flow rates, based on the actuatorsizes and speeds.

Calculate the power required to supply the flowsand pressures for the system to meet the specifiedcycle time.

Conditions Use manufacturers catalogues, charts, computerspread sheets or nomographs to allow thislearning outcome to be performed as effectivelyand efficiently as possible.

Assessment methods Written answer questions of typical calculationsused in this learning outcome.

Learning outcome 5 Select the type of system which best suits thepressures and flows of the design.

Assessment criteria Select the actuators where there is high flowand/or power during the cycle.

Compare the flows, powers, size of componentsand circuit requirements using different designmethods.

Select the most suitable design method to meet thesystem requirements.

Condition

Assessment method Written answer questions



Learning outcome 6 Optimise the system to reduce flows,pressures and powers. This may requiresome changes to the design parameters,changes to cycle times or methods ofoperation to optimise the system.

Assessment criteria Calculate the pressures, flows and powers fordifferent pressures, cycle times or methods ofoperation to optimise the system.

Select the most suitable parameters to optimisethe system design.

Condition

Assessment method Written answer test

Learning outcome 7 Determine the control requirements forthe hydraulic pneumaticand PLC/electrical/electronic system to meetthe needs of the system.

Assessment criteria Identify the parameters which will determine thecontrol requirements for the system.

Determine the control needs for the hydraulic andpneumatic circuit, as well as for the PLC to meetthe control parameters.

List the inputs and outputs required for the PLC

Draw the solenoid energising chart

Write logic statements which will allow the PLCprogramme to be written

Condition

Assessment method Written answer test



Learning outcome 8 Summarise the system design, and use thissummary to select the type of system to beused, and the control requirements. Use thissummary to determine the feasibility of theproposed design.

Assessment criteria Draw a step/time diagram and flow/time diagramfor the system.

Summarise the calculations onto a chart to showall forces, times, strokes, pressures, flow ratesand actuator sizes.

Determine the feasibility of the design to meet thespecification and design parameters.

Conditions

Assessment method A minor written report, which should include asummary of the calculation results and afeasibility statement for the system.

Suggested LearningResources

“Design Engineers Handbook”Parker Hannifin Corporation.

“Analyzing Hydraulic Systems”Parker Hannifin Corporation.

“Hydraulics. Theory and Application”Robert Bosch.Gmbh.

“Industrial Hydraulic Control”Peter Rohner - AE Press

“Pneumatic Control for Industrial Automation”Peter Rohner - A E Press

“Using Industrial Hydraulics”T.C. Frankenfield - Rexroth.

“The Hydraulic Trainer Volume 2”Mannesman Rexroth. GMBH





“Electronically Controlled Proportional Valves” Michael J. Tonyan - Marcell Dekker Inc.

“Hydraulic Systems Analysis” George R. Keller

“Fundamentals of Control Engineering” Festo Didactic

“Simple Memory and Logic Circuits” Festo Didactic

“Introduction to PLCs” Festo Didactic

“Power Trains” F.O.S. John Deere

“Industrial Fluid Power Volume 3” Womack Educational Publiations

“Fundamentals of Fluid Mechanics” James A.Sullivan, Reston Publishing Company.

“Hydraulic Control Systems - Design and Analysis of Their Dynamics”

Peter Dransfield Springer - Verlag.

“Fluid Power - Systems and Circuits” Russell W.Henke.

“Basic Principles of Proportional Valves” Vickers Systems.

“Basic Electronics for Hydraulic Engineers” Vickers Systems.

Swain - Eb723pdf

Documents

Transcript of Swain - Eb723pdf