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SRI MUTHUKUMARAN INSTITUTE OFTECHNOLOGY

V.NarendranathT.PrasathP.PramanayagamE.Ravikumar

Double Side Compressor usingScotch Yoke Mechanism

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What is

Mechanism?

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In mechanical construction, the means

employed to transmit and modifymotion in a machine or any assemblage

of mechanical parts. The chiefcharacteristic of the mechanism of amachine is that all members have

constrained motion; i.e.,the parts canmove only in a determinate manner

relative to one another.

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This linkage is being called by a Scotsman

in 1869 a "crank and slot-headed slidingrodBut now it is known as a Scotch yokebecause, in America at least, a "Scotch"

was a slotted bar that was slipped undera collar on a string of well-drilling tools tosupport them while a section was being

added In 1940 Russell Bourke applied this

mechanism to the internal combustionengine called Bourke 30 engine

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Mechanism for converting the

linear motion of a slider into

rotational motion or vice-versa.

The Scotch Yoke performs muchthe same function as the simple

crank.

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PARTS OF SCOTCH YOKE

CrankSlider & Yoke

FrameFrame

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High torqueoutput with a smallcylinder size.

Fewer moving parts.

In an engine application, eliminationof joint typically served by a wrist pin,and near elimination of piston skirt

and cylinder scuffing, as side loadingof piston due to sine of connectingrod angle is eliminated.

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Rapid wear of the slot in the yoke caused bysliding friction and high contact pressures.More heat loss during combustion due to

extended dwell at top dead center off sets

any constant volume combustionimprovements in real engines.

Lesser percentage of the time spent at

bottom dead center reducing blow downtime for two stroke engines, when comparedwith a conventional piston and crankshaftmechanism.