Lesson Notes By Weeks and Term - Junior Secondary School 2

SUBJECT:��BASIC TECHNOLOGY �� ���

CLASS:� JSS2

DATE:

TERM: 3RD TERM

REFERENCE MATERIALS�

• MELROSE, Basic Science and Technology Book 2
• NERDC, Basic Technology for JSS, Book 2

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WEEK SIX

TOPIC: HYDRAULICS AND PNEUMATIC MACHINES

CONTENT

• Definition�
• Types
• Uses

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DEFINITION - HYDRAULICS AND PNEUMATICS

Hydraulics is the branch of science and technology concerned with the conveyance of liquids through pipes and channels, especially as a source of mechanical force or control. When compressed air (gas) is the liquid, it is called Pneumatics. Hydraulic systems tend to be used at a much higher pressure than pneumatic systems. Consequently, the former can produce much larger forces and torque than the latter.

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SIMPLE HYDRAULIC AND PNEUMATIC MACHINES

1. Simple Force Pump: Pumps are used to move gases and liquids by applying pressure greater than those of the gases or liquids. The simplest pump is the bicycle pump that moves air through the pump to the bicycle. Another simple pump is the suction pump. It is used for lifting liquids from a low level.
2. Centrifugal pump: This has a set of moving vanes which receive the the fluid (air or water) at a smaller radius
3. Hydraulic Jack: The discharge action in the hydraulic jack moves the liquid into a high pressure compartment. The piston is equipped to carry heavy loads such as cars.
4. Garden sprinkler: This consists of one or more water jets which can revolve about the center as it sprinkles water in a lawn or garden.
5. �Reaction turbine
6. The waterwheel�

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USES/APPLICATION OF PNEUMATICS

1. Air brakes on buses, trucks and trains
2. Air compressors
3. Air engines for pneumatically powered vehicles
4. Pressure sensor
5. Pressure regulator and switch
6. Vacuum pump etc

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USES/APPLICATION OF HYDRAULICS

1. Hydraulic Press
2. Breaks in cars, motorbikes and bicycles often use hydraulic systems to force to break pads
3. Office chairs
4. Boats and airplanes
5. Excavators and dump trucks use hydraulic pistons to control their equipment

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EVALUATION

1. Define (a) Hydraulics (b) Pneumatics
2. State five (5) hydraulic and pneumatic machines
3. List five(5) applications of Hydraulics and Pneumatics

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GENERAL EVALUATION

1. �Differentiate between Hydraulic and Pneumatic Systems�
2. State five (5) applications each of Hydraulics and Pneumatics
3. List five (5) Hydraulic and Pneumatic devices

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READING ASSIGNMENT

Read about Site Preparation (NERDC Basic Tech. for JSS2 page121-123)

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WEEKEND ASSIGNMENT

1. The branch of science and technology concerned with the conveyance of liquids through pipes and channels, especially as a source of mechanical force or control. (a) Pneumatics (b) Hydraulics (c) Gearing system (d) Mechanical system

2. Which of the following can be used to carry heavy loads such as car? (a) Centrifugal pump (b) Garden sprinkler (c) The waterwheel (d) Hydraulic Jack

3. Examples of application of pneumatic include the following except (a) Pressure sensor (b) Office chairs (c) vacuum pump (d) pressure regulator
4. The following are applications of hydraulics except (a) Hydraulic press (b) Air compressor (c) Boats (d) Excavators
5. Excavators and dump trucks use __________ to control their equipment (a) hydraulicjack (b)hydraulic press (c) hydraulic pistons (d) hydraulic fluid

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THEORY

1. List five application each of hydraulic and pneumatics
2. State five types of hydraulic and pneumatics machine with their uses

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