The crank-slider mechanism

One of the major discoveries

by Imad Benacer

Imad Benacer is a PhD candidate at Polytechnique School of Montreal in Computer Engineering

Imad Benacer is a PhD candidate at Polytechnique School of Montreal in Computer Engineering

One of the major discoveries in our century is the modern machinery such as combustion engine. Can anyone imagine a world without trains, cars, boats, etc?  This was possible with the discovery of crank-slider mechanism which constitutes the central piece of these amazing machines. 

In the 5th century BC, one of the first crank uses was as an eccentrically mounted handle of the rotary hand mill that spread across the Roman Empire. The earliest evidence of a crank and connecting rod mechanism dates to the 3rd century AD in the Hierapolis sawmill. The crank also appears in the 9th century in several of the hydraulic devices described by the Banu Musa brothers in their book of ingenious devices. In 1206, Al-Jazari invented an early crankshaft, which he incorporated with a crank-connecting rod mechanism in his twin-cylinder pump as an automated water elevation machine. Al-Jazari water pump employed the first known crank-slider mechanism.

Figure: Al-djazari twin-cylinder water pump.

Figure: Al-djazari twin-cylinder water pump.

Like the modern crankshaft, Al-Jazari's mechanism consisted of a wheel setting several crank pins into motion, with the wheel's motion being circular and the pins moving back-and-forth in a straight line. The crankshaft described by al-Jazari transforms continuous rotary motion into a linear reciprocating motion; this is central to modern machinery such as the steam engine, internal combustion engine, etc that appeared after five centuries after Al-djazari invention in the industrial revolution.

A great discovery is preceded by a lot of work and earlier processes. Meanwhile, a discovery in one field does not mean it is only applicable to it, but how to change it and adapt it to other fields from water elevation systems to engines is an example of discovery innovation. 


References

[1] Web site: https://en.wikipedia.org/wiki/Ismail_al-Jazari, access date: Feb. 2016.  

[2] Web site: http://www.1001inventions.com/, access date: Feb. 2016.