load sensing2

Service TrainingAugust 1998

INSTRUCTOR GUIDE

INTRODUCTION TOLOAD SENSING/PRESSURE COMPENSATED HYDRAULIC

SYSTEMS

ENGINE

VARIABLEDISPLACEMENT

PUMP

CLOSED CENTERCONTROL VALVE

DOUBLECHECK VALVE

PRESSUREREDUCING VALVE

50 PSISPRING

PUMPCONTROL

VALVE LOAD

LOAD SENSING / PRESSURE COMPENSATION

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COURSE DESCRIPTION

Introduction to Load Sensing / Compensated HydraulicsCourse Length: 1/2 DayClass size: 8 students maximum

WHO SHOULD ATTEND:• Training Instructors• Technical Communicators• Product Support Engineers• Service Technicians

This module of course explains a typical basic hydraulic system andbuilds it step-by-step into a Load Sensing / Pressure Compensatedhydraulic system. Participants will learn about the advantages anddisadvantages of a basic system versus a LS/PC system. A studenthandbook and quiz is provided to assist the students in learning theconcepts of LS/PC. Students will be challenged to determine whathappens as load and flow requirements change to the systems covered.

This is a classroom based program and is normally taught as part of thehydraulic system training for a particular machine

This module can stand a lone, but for better retention of the informationrefer to materials in the BCP Backhoe Loader Systems Course for variousin the iron type exercises.

COURSE PRE-REQUISITES

Prerequisite tests should be administered at least one to two weeks beforestudents take the course.

Students should pass the following pretests with 90% or better.

• Successfully passed the Basic ISO Pre-test VEBV0556• Successfully passed the Basic Hydraulic Pretest VEBV0557

Prerequisite courses should be completed prior to participating in thiscourse.

• Multimedia Course "Fundamentals of Mobile Hydraulics" TECD9001

CONTENT


PREPARATION CHECKLIST

Prior to conducting the training session, gather the following materials:

Service Training Meeting Guides

STMG 595 "Introduction to Load Sensing Pressure CompensatedHydraulic Systems" SESV1595

Video Tapes

"Introduction to LS/PC Hydraulics Systems" SEVN1804

Miscellaneous - for Reference only

"Introduction to LS/PC Hydraulics Systems" SEEV0540"Introduction to Variable Displacement Pumps and Controls in LS/PC Hydraulics" SEEV0541"Introduction to Pressure Compensated Valves in LS/PC Hydraulics" SEEV0542"Introduction to 416-446 Backhoe Loader Hydraulics"SEEV0543

"Introduction to Variable Displacement Pumps and Controls in LS/PC Hydraulics" SEVN1837"Introduction to Pressure Compensated Valves in LS/PC Hydraulics" SEVN1900"Introduction to 416-446 Backhoe Loaders - LS/PC Hydraulics"

SEVN1988

STUDENT LITERATURE CHECKLIST

Description Form No.

"Introduction to Load Sensing Pressure CompensatedHydraulic Systems" Student Handbook

MEDIA CHECKLIST

SESV1595: 1-13

SESV1595: 14 & 15 are optional


COURSE PLAN/OUTLINE

GET ACQUAINTED

MODULE: INTRODUCTION TO LOAD SENSING PRESSURECOMPENSATED HYDRAULICS

- Objectives- Lesson: Basic LS/PC Hydraulics

- Slide presentation on LS/PC hydraulics- Quiz: LS/PC Hydraulics

MODULE: INTRODUCTION TO LOADSENSING PRESSURE COMPENSATEDHYDRAULICS

This module is a review of basic "load sensing/pressure compensated"hydraulics.

OBJECTIVES

1. On a quiz in the back of the Student Handbook, identify systemcharacteristics of Load Sensing and Pressure Compensation andcomponents used in this type of hydraulic system.

2. On a quiz in the back of the Student Handbook, determine systempressures and pressure differences at various locations on providedquiz schematics.

PREPARATION CHECKLIST

Lesson: Load Sensing / Pressure Compensated Hydraulics

Materials Needed:

LS/PC Student Handout with Quiz

Slides Required:

SESV1595: 1-13

SESV1595: 14 & 15 are optional

Video (optional)

"Introduction to LS/PC Hydraulics Systems" SEVN1804

Approx. time: 2 - 3hours

Approx. time: 1/2 hour

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Lesson: Load Sensing / Pressure Compensated Hydraulics

Before showing the slides the instructor should review the quiz that willfollow with the students

Slide Presentation:

• LS/PC system review - These slides review the basic principles of loadsensing and pressure compensation

- Provide students with copies of the LS/PC Student Handout

- The last three pages of the handout has a quiz, which the studentmust complete.

• (Optional) LS/PC system review using a Video - The LS/PCIntroduction Video may be used in place of the slides to complementthe instructor's knowledge.

• Review Quiz

BEGIN MODULE

• Review objectives andperformance lessons

Approx. Time: 3 min.

SHOW SLIDES:SESV1595: 1 - 13

Approx. Time: 2 hours

SHOW SLIDES:SESV1595: 1 - 13


ADMINISTER QUIZ



I. Match the following:

1. A

2. E

3. D

4. B

5. C

II. True/False.

A. F "closed"

B. T

C. T

D. T

E. F "double check valve"

III. Fill in the correct response.

System pressure will be: 1800 psi + 300psi = 2100psi

Valve A work port pressure = 1800 psi

∆ P across pressure reducing valve = 2100 psi - 1890 psi = 210 psi

∆ P across control spool = 1890 psi - 1800 psi = 90 psi

Valve B work port pressure = 700 psi

∆ P across pressure reducing valve = 2100 psi - 760psi = 1340 psi

∆ P across control spool= 760 psi - 700 psi = 60 psi

IV. Fill in the correct response.

System pressure will be: 3000 psi + 0 psi = 3000 psi

Valve A work port pressure = 3000 psi


∆ P across control spool = 3000 psi - 3000 psi = 0 psi

Valve B work port pressure = 1000 psi


∆ P across control spool= 1060 psi - 1000 psi = 60 psi

LS/PC QUIZ ANSWERS

load sensing2

Documents