Crankshaft
Channel: all the knowledge of the universe PRINCIPIA
Date: 2021-12-10

Crankshaft, by Wikipedia https://en.wikipedia.org/wiki?curid=7249 / CC BY SA 3.0

#Crankshafts
#Arab_inventions
#Engine_components
#Engine_technology
#Linkages_(mechanical)
#Piston_engines
#Turkish_inventions
Flat-plane crankshaft （red）, pistons （gray） in their cylinders （blue）, and flywheel （black） A crankshaft is a shaft driven by a crank mechanism, consisting of a series of cranks and crankpins to which the connecting rods of an engine is attached.
It is a mechanical part able to perform a conversion between reciprocating motion and rotational motion.
In a reciprocating engine, it translates reciprocating motion of the piston into rotational motion, whereas in a reciprocating compressor, it converts the rotational motion into reciprocating motion.
In order to do the conversion between two motions, the crankshaft has "crank throws" or "crankpins", additional bearing surfaces whose axis is offset from that of the crank, to which the "big ends" of the connecting rods from each cylinder attach.
It is typically connected to a flywheel to reduce the pulsation characteristic of the four-stroke cycle, and sometimes a torsional or vibrational damper at the opposite end, to
reduce the torsional vibrations often caused along the length of the crankshaft by the cylinders farthest from the output end acting on the torsional elasticity of the metal.
Schematic of operation of a crank mechanism Han China Tibetan operating a quern （1938）.
The upright handle of such rotary handmills, set at a distance from the centre of rotation, works as a crank.
The earliest hand-operated cranks appeared in China during the Han Dynasty （202 BC-220 AD）.
They were used for silk-reeling, hemp-spinning, for the agricultural winnowing fan, in the water-powered flour-sifter, for hydraulic-powered metallurgic bellows, and in the well windlass.
The rotary winnowing fan greatly increased the efficiency of separating grain from husks and stalks.
However, the potential of the crank of converting circular m...