HU 121 History of Engineering and Technology Fall 2012/13 Pharos University in Alexandria Faculty of Engineering Engines Lect6

HU121_Lect6_Engines2 Outline Engines –Definition –Types The Cam –Al Jazari Engines –Al Jazari Cam Pumps Internal Combustion Engine Review Questions at the end

HU121_Lect6_Engines3 Engine An engine converts energy Into useful mechanical motion.

HU121_Lect6_Engines4 Types of Engines 1.Water-driven Engine (water wheels --> water turbines) 2.Wind-driven Engine 3.Steam Engine 4.Internal Combustion Engine 5.Electromagnetic Engine (Motor) 6. Jet Engine

HU121_Lect6_Engines5 Al Jazari The first known engines were described by Al Jazari in the 13 th 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 أبُو اَلْعِزِ بْنُ إسْماعِيلِ بْنُ الرِّزاز الجزري

HU121_Lect6_Engines6 Al Jazari Mechanical Devices Cam Crankshaft and crank- slider mechanism Water-raising machines Automata Clocks

HU121_Lect6_Engines7 Evolution of the Camshaft Roman sawmill camshaft 3rd century Al Jazari Water Raising Engine 13 th Century da Vinci crank and rod 16 th Century

HU121_Lect6_Engines8 Cam Shaft Converts up and down or reciprocating motion into rotary motion or vice versa.

HU121_Lect6_Engines9 Al Jazari’s Camshaft The camshaft was conceived and described by Al-Jazari in 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_Lect6_Engines10 Al Jazari Double-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_Lect6_Engines11

HU121_Lect6_Engines12 Internal Combustion

HU121_Lect6_Engines13 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_Lect6_Engines14 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_Lect6_Engines15 Multiplex Pump

HU121_Lect6_Engines16 Review Questions 1.(a) Define an engine (b) List four types of engines in chronological order 2.(a) Sketch and describe a Camshaft (b) Name two modern applications of camshafts 3. Al Jazari is considered one of the founders of modern engineering. (a)In what century did Al Jazari live? (b)List his major engineering contributions 4. Discuss the main features of Al Jazari Double-acting Piston Engine 5. Describe briefly the role of the cam mechanism in (a) An internal combustion engine and (b) A suction pump