Chapter 7 - Hydraulic Operation Circuit and Application

MEM341: FLUID POWER TECHNOLOGYMEM341: FLUID POWER TECHNOLOGYMEM341: FLUID POWER TECHNOLOGYMEM341: FLUID POWER TECHNOLOGY

EP Chiang UiTMPP FKM

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8. Hydraulic Circuit

Introduction

In this chapter we will discuss basic hydraulic circuits that used the most basic components that make up a hydraulic system. Basic electrical control devices (push button switches, pressure switches, solenoids, relays, timers and basic electrical control devices (ladder diagram) will not be included. A hydraulic circuit is a group of components such as pumps, actuators, control valves and conductors (pipes) are arranged so that they will perform a certain task. Three important factors when analyzing or designing hydraulic circuit: 1. safety of operation 2. performance of desired function 3. efficiency of operation Circuit drawing has to be done using standards that are recognized worldwide. Standard are important for the following reasons: 1. interchangeable of components 2. symbols and circuit diagrams can be read by everyone. So that the hydraulic circuit

can be interpreted and install correctly. The standards organizations in this field are: 1. BS (British Standards) 2. ANSI (American National Standards Institution) 3. ISO (International Standards Organization)



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CONTROL OF A SINGLE ACTING HYDRAULIC CYLINDER

CONTROL OF DOUBLE ACTING HYDRAULIC CYLINDER



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REGENERATIVE CYLINDER CIRCUIT

Used to speed up the extending speed of a double acting cylinder, but this also will

reduce the load carrying capability of the cylinder during extension.



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REGENERATIVE CIRCUIT EXAMPLE Drilling Machine

Application

PUMP UNLOADING CIRCUIT



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DOUBLE PUMP HYDRAULIC SYSTEM

COUNTERBALANCE VALVE APPLICATION



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BASIC SEQUENCING CIRCUITS

AUTOMATIC CYLINDER RECIPROCATING SYSTEM



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LOCKED CYLINDER USING PILOT CHECK VALVES



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CYLINDER SYNCHRONIZING CIRCUITS



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FAIL SAFE CURCUITS



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Two handed safety circuit



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SPEED CONTOL OF A HYDARULIC CYLINDER

(METER-IN)

(METER-OUT)



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SPEED CONTROL OF A HYDRAULIC MOTOR

HYDRAULIC MOTOR BRAKING SYSTEM



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HDROSTATIC TRANSMISSION SYSTEM



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AIR-OVER-OIL CIRCUIT

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Chapter 7 - Hydraulic Operation Circuit and Application