HU 121 History of Engineering and Technology Fall 2013/14 Pharos University in Alexandria Faculty of Engineering Engines Lect5
Jan 15, 2016
HU 121 History of Engineering and Technology
Fall 2013/14
Pharos University in AlexandriaFaculty of Engineering
Engines
Lect5
HU121_Lect5_Engines 2
Outline• Engines
– Definition – Types
• The Cam– Al Jazari Engines– Al Jazari Cam
• Pumps• Internal Combustion Engine
HU121_Lect5_Engines 3
Engines
An engine converts energy
Into useful mechanical motion.
Lecture 7
?Mechanisms
HU121_Lect5_Engines 4
Al Jazari• The first known engines were
described by Al Jazari in the 13th century.
• Al-Jazari inherited the knowledge of his predecessors, but he improved on their designs and added his own.
• His book Al-Jami’ bayn al-Ilm wal Amal Al-Nafi’ fi Sina’at Al-Hiyal (Book of Knowledge of Ingenious Mechanical Devices) is a pioneering book in engineering.
• This book was translated to English by Donald Roultedge Hill in 1947.
ب�ن� أ ماع�يل� إس� ب�ن� �ل�ع�ز� ا ب�والجزري زاز الر�
HU121_Lect5_Engines 5
Al Jazari Major Mechanical Devices
• Cam• Crankshaft and crank-
slider mechanism• Water-raising
machines• Automata • Clocks
HU121_Lect5_Engines 6
Al JazariDouble-acting Piston Engine
Main Features:1. it converts rotary motion
into reciprocating motion through the crank-connecting-rod mechanism.
2. it employs a double-acting principle (at the same time as one piston sucks, the other one delivers the water).
3. it is the first pump known to have had true suction pipes.
HU121_Lect5_Engines 7
• As the animal walks in a circle the horizontal axle is turned by the gears and the end of the crank slides in the hinged connecting rod causing it to oscillate around its hinge and thus causing the swape to rise and fall.
• Fig 3 is a line drawing of the mechanism for this machine
HU121_Lect5_Engines 8
Al Jazari’s Camshaft• The camshaft was conceived and
described by Al-Jazari in 1206. • He implemented the camshaft
as part of – automata, – water-raising machines, and – water clocks.
• The cam and camshaft later appeared in European mechanisms from the 14th century.
• The camshaft is an essential mechanism for conceiving
and designing the Internal combustion engines and pumps.
HU121_Lect5_Engines 9
HU121_Lect5_Engines 10
HU121_Lect5_Engines 12
The Role of the Cam in an Internal Combustion Engine
• In the internal combustion system the cam and follower system are required to control the opening and the closing of the inlet and exhaust valves.
HU121_Lect5_Engines 13
Cam Pump
The follower is cylindrically shaped and moves within a tight fitting cylinder so liquid is sucked in and pushed out as the follower moves up and down.
HU121_Lect5_Engines 14
Multiplex Pump
HU121_Lect5_Engines 15
Review Questions1. Al Jazari is considered one of the founders of
modern engineering.(a) In what century did Al Jazari live?(b) List five of his major engineering contributions
2. Discuss the main features of Al Jazari Double-acting Piston Engine
3. Describe briefly the role of the cam mechanism in
(a) An internal combustion engine and(b) A suction pump