Standard

 

DET 231 - Hydraulic Systems III

Course Description

A continuation of DET 230, introducing hydraulic systems and components used on heavy equipment.  Classroom and lab instruction on components and systems emphasizes the use of testing and diagnosis equipment.  Topics include:  pumps, valves, cylinders, motors, hydraulic circuits, and diagnosis & testing.

 

Competency Areas

Hours

 

Pumps

Class

1

Valves

D. Lab

0

Cylinders

P. Lab/O.B.I.

9

Motors

Credit

4

Hydraulic Circuits

 

 

Diagnosis and Testing

 

 

 

Prerequisite:

DET 230

Corequisite:

     

 

Course Guide

 

Competency

After completing this section, the student will:

Hours

Class

D.Lab

P.Lab/

O.B.I.

PUMPS

2

0

10

 

Understand terms and definitions

 

 

 

 

Identify positive and nonpositive displacement pumps

 

 

 

 

Identify kinds of positive displacement pumps

 

 

 

 

Describe calculation of pump displacement

 

 

 

 

Describe calculation of pump flow rate

 

 

 

 

Describe calculation of pump input and output power

 

 

 

 

Describe calculation of pump volumetric efficiency

 

 

 

 

Describe operation of gear pump

 

 

 

 

Describe operation of vane pump

 

 

 

 

Identify axial and radial piston pumps

 

 

 

 

Describe construction and operation of axial piston pumps

 

 

 

 

Describe operation of a variable displacement axial piston pump

 

 

 

 

Identify parts of a servo-controlled variable displacement pump

 

 

 

 

Identify components and functions of pressure compensated axial piston pumps

 

 

 

 

Identify causes of cavitation

 

 

 

 

Identify causes of pump failure

 

 

 

 

Identify symbols for pumps

 

 

 

 

Disassemble, inspect, and reassemble a gear pump

 

 

 

 

Disassemble, inspect, and reassemble a pressure compensated variable displacement pump

 

 

 

VALVES

2

0

20

 

Understand terms and definitions

 

 

 

 

Define categories of valves

 

 

 

 

Identify types of pressure control valves

 

 

 

 

Identify types of electro/hydraulic valves

 

 

 

 

Identify micro processor control valves

 

 

 

 

Identify types of pressure relief valves

 

 

 

 

Describe operation of a pressure reducing valve

 

 

 

 

Identify types of flow control valves

 

 

 

 

Describe operation of a needle valve as a flow control device

 

 

 

 

Describe operation of a high pressure compensated flow control valve

 

 

 

 

Describe operation of priority flow divider

 

 

 

 

Describe operation of a proportional flow divider

 

 

 

 

Identify types of directional control valves

 

 

 

 

Describe operation of a check valve and a spool direction control valve

 

 

 

 

Identify flow paths in a directional control valve

 

 

 

 

Identify open and closed center systems

 

 

 

 

Identify types of actuators

 

 

 

 

Identify symbols for hydraulic valves

 

 

 

 

Disassemble, inspect, and reassemble a pressure control valve

 

 

 

 

Disassemble, inspect, and reassemble a flow control valve

 

 

 

 

Disassemble, inspect, and reassemble a directional control valve

 

 

 

CYLINDERS

1

0

10

 

Understand terms and definitions

 

 

 

 

Describe operations of a hydraulic cylinder

 

 

 

 

Describe operations of a single and double-acting cylinders

 

 

 

 

Identify types of double-acting cylinders

 

 

 

 

Identify parts of a single-acting cylinder

 

 

 

 

Identify parts of a double-acting cylinder

 

 

 

 

Identify sources of common failures of hydraulic cylinders

 

 

 

 

Identify force output of a cylinder

 

 

 

 

Describe speed of a hydraulic cylinder

 

 

 

 

Identify flow rate required to move a cylinder a given distance in a given time

 

 

 

 

Identify symbol for a cylinder

 

 

 

 

Disassemble, inspect, and reassemble a hydraulic cylinder

 

 

 

 

Test a cylinder for internal and external leakage

 

 

 

MOTORS

1

0

10

 

Understand terms and definitions

 

 

 

 

Identify kinds of hydraulic motors

 

 

 

 

Identify formula for calculating hydraulic motor load torque

 

 

 

 

Identify formula for calculating displacement of motor

 

 

 

 

Identify formula for calculating speed of a motor

 

 

 

 

Identify formula for calculating inlet pressure

 

 

 

 

Identify formula for calculating motor input and output

 

 

 

 

Identify formula for calculating overall motor efficiency

 

 

 

 

Describe operation of a gear motor

 

 

 

 

Describe operation of an unbalanced motor vane

 

 

 

 

Identify types of piston motors

 

 

 

 

Describe operation of an in-line axial piston motor

 

 

 

HYDRAULIC CIRCUITS, DIAGRAMS, AND SYMBOLS

2

0

20

 

Understand terms and definitions

 

 

 

 

Identify components of a basic hydraulic circuit

 

 

 

 

Identify types of hydraulic circuits

 

 

 

 

Describe advantages and disadvantages of open-center and closed-center systems

 

 

 

 

Identify fluid flow in an open-center circuit

 

 

 

 

Identify fluid flow in multiple actuator open-center systems

 

 

 

 

Identify valves in neutral and shifted positions in fluid flow

 

 

 

 

Identify symbols used in a hydraulic schematic

 

 

 

 

Identify symbols for directional control valves

 

 

 

 

Identify schematic of open and closed-center systems

 

 

 

 

Draw an open-center hydraulic circuit

 

 

 

 

Show the oil flow in a circuit

 

 

 

DIAGNOSIS AND TESTING

2

0

20

 

Understand terms associated with diagnosis and testing

 

 

 

 

Identify steps in troubleshooting

 

 

 

 

Identify types of hydraulic system testers

 

 

 

 

Describe problems and remedies for an inoperative system

 

 

 

 

Describe problems and remedies for an erratic system

 

 

 

 

Describe problems and remedies for a slow system

 

 

 

 

Describe problems and remedies for a fast system

 

 

 

 

Describe problems and remedies for a over-heated system

 

 

 

 

Describe problems and remedies for the foaming of fluid

 

 

 

 

Describe problems and remedies for excessive noise

 

 

 

 

Describe problems and remedies for a leaking pump

 

 

 

 

Describe problems and remedies for a load drop

 

 

 

 

Describe problems causing valves to stick or work hard

 

 

 

 

Describe problems causing control valves to leak

 

 

 

 

Describe problems causing a cylinder to leak

 

 

 

 

Describe problems in lowering and raising with a control valve

 

 

 

 

Describe problems and remedies for power steering malfunctions

 

 

 

 

Describe problems and remedies for brake malfunctions

 

 

 

 

Test a hydraulic pump

 

 

 

 

Locate a problem in a hydraulic system

 

 

 

 

Test a relief valve

 

 

 

 

Test a control valve

 

 

 

 

Test an actuator

 

 

 

 

Suggested Resources

Mitchell Information Systems.  (2002).  “Mitchell on Demand”.  San Diego, California.

Multistate Academic and Vocational Curriculum Consortium.  (2002).  “Diesel Technology Series”.   Stillwater, Oklahoma.

Norman, Andrew & others.   (2001).  Diesel Technology.  Tinley Park, Illinois:  Goodheart-Willcox.

Norman, Andrew & others.   (2001).  Heavy Duty Truck Systems.  Albany, New York:  Delmar Publishing.

Norris, David & Tony Elkins.  (2002).  Automotive Information Specialists.  Gulf Breeze, Florida:  Motor/Alldata.