24-09-2014, 09:47 AM
SIX STROKE ENGINE
SIX STROKE ENGINE.ppt (Size: 763 KB / Downloads: 167)
Introduction
A six stroke engine derived its name from the fact that it is a mixture of two and four stroke engine.
This engine is a radical hybridization of two and four stroke engine that the top portion of two stroke engine and the bottom rather the middle section of a four stroke engine
Principles of Two Stroke
Two stroke engines got its name from the fact that the required strokes are completed in one revolution.
In short there is one power stroke in one revolution.
Principles of Four Stroke
In the case of four stroke engines, the four strokes are completed in two revolutions.
There is a single power stroke in two revolutions.
Concept of Six Stroke
This technology is also known as Beare Technology.
This engine got its name due to its construction.
This engine is a radical hybridization of two and four stroke engines.
These types of engines have many advantages compared to OHC four stroke engines.
Construction
The drawbacks of poppet valves in conventional engines is overcome by means of a rotary valve application to four-stroke engine.
To replace the camshaft and valves, Beare has retained the cam drive belt and fitted an ultra short-stroke upper crankshaft complete with piston, which the belt drives at half engine speed just as it previously drove the cam
Construction
It consist the basic components of a rotary disc induction two-stroke engine.
It is grafted on to a four-stroke, to produce the best of both worlds.
Working
The top piston drives up and down in a sleeve, past inlet exhaust ports set into the cylinder wall, very much like on a two-stroke.
During the compression and expansion strokes, the upper piston seals off both ports.
In the combustion phase, twin spark plugs provide ignition via the stock Ducati CDI and a pair of Harley coils - one per cylinder. (sixstroke small.avi, sixstroke.avi)
Conclusion
The industry trend away from cheaper two-stroke power in favor of costlier but cleaner four-stroke engines in both Europe, Japan and South East Asia makes a concept like the Beare six-stroke, which offers the best of both worlds, project a strong case towards volume manufacture.
150cc six-stroke Taiwanese single-cylinder bike from Yingang is ready to roll.