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VISVESVARAYA TECHNOLOGY UNIVERSITYBELGUM

NEW HORIZON COLLEGE OF ENGINEERINGSEMINAR

ON

BALL PISTON ENGINEDEPARTMENT OF MACHINE DESIGN

PRESENTED BY

SHARATH KUMAR H A1NH14MMD14Mtech ,1st sem,

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CONTENTS1. INTRODUCTION2. MODE OF OPERATION3. DESIGN FEATURES4. MATERIAL SELECTION5. WORKING OF ENGINE6. LUBRICATION7. ADVANTAGES8. DISADVANTAGES9. APPLICATION10.CONCLUSION11.REFERENCES

INTRODUCTION• The Ball piston engine (Wolf hart engine) is an

[[internal combustion engine /internal combustion]]rotary engine that uses two interwinded rotors insteadof reciprocating pistons.

• A spherical piston rotates in combination with aspherical housing, whereby the rotational axes inclinetowards each other slightly.

• In these way “strokes” are created within the rotationalsystem generating periodic volumetric changes in theworking chambers adjacent to the dividing wall

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MODE OF OPERATION• The ball pistons rolling on an eccentric track. The

balls exert tangential force on the cylinder wallswhich turn the rotor.

• The useful power is available at the rotor outputshaft.

• The combustion chambers are within the spinningrotor. Chamber porting for intake, compression,power, and exhaust strokes is achieved by passageof the chamber tops across an internal stator withappropriate feeds as the rotor spins.

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DESIGN FEATURES• The basic operation of the new design is

conventional for an internal combustion engine, i.e.a piston reciprocates within a cylinder, and withporting, implements the four strokes of the Ottocycle.

• However, there are a number of features that makethis engine design favorable for high efficiency andemissions control.

• The porting required for four stroke operation isachieved with no additional moving parts, and novalve train losses

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MATERIAL SLECTION• A series of tests to characterize friction and wear of various

materials in a simulated ball piston engine/compressor wereperformed to aid in selection of production materials.

• Another goal of the tests was to explore this machine couldrun without lubrication.

• If un lubricated operation was not possible, tests withinstrumentation would be used to confirm the lubricatedoperation of the machine and the resulting internal loads.

• Friction at conventional piston rings, piston pin, andconnecting rod/crankshaft bearing are eliminated ). Therotor/stator bearing is of a gas or fluid hydrostatic type, sofriction is very low at that site

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WORKING OF ENGINES(SUCTION STROKE)

Beginning at top deadcenter (TDC) at 0 degreesrotation, the stator intakepassage is open to thecylinder and a fuel/aircharge is pulled into thecylinder as the ball pistonmoves radially outward forthe first 90 degrees ofrotation .

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WORKING OF ENGINE(COPRESSION STROKE)

Then the intakepassage is closed off,and the ball reversesradial direction for thenext 90 degrees ofrotation, during whichtime the new charge iscompressed(compression stroke).

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WORKING OF ENGINE(POWER STROKE)

Just past 180 degrees rotation, thecompressed charge is ignited as thecylinder port passes a small ignitorport. Combustion ensues, and the highcombustion pressure pushes radiallyoutward on the ball piston for the next90 degrees of rotation. The ball in turnpushes tangentially on the cylinderwall because of the "slope" of theeccentric ball track, which is nowallowing the ball to move radiallyoutward. The tangential forceproduces useful torque on the rotor(power stroke

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WORKING OF ENGINE (EXHAUST STROKE)

At 270 degrees of rotation,the spent combustion chargeis allowed to escape throughthe exhaust passage as thecylinder port is uncovered.Exhaust is expelled as the ballmoves radially inward for thenext 90 degrees of rotation(exhaust stroke). Then thecycle repeats.

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LUBRICATIONAs is the case with a standard four-stroke engine, an oil bathis situated behind the piston, which in turn is fitted with oilscraper rings. Here attention must merely be paid to ensuring that the oilgathers externally, because of the rotation. In fact, if outlet portsare placed in this area for the oil, an oil pump can be potentiallydispensed .Otherwise, oil that is pumped into the center also carries heatfrom the interior to the exterior,which in turn can be utilizedfor cooling purposes

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ADVANTAGESThe stroke magnitude and rate can be different for different strokein cycle so that it provides the possibility of converting more energyto the shaft power by greater expansion during the power stroke.

It has ability (i.e. in multi energy domain engine) to complete anyeven numbers of strokes per revolution in single rotation of rotor

There is no much moving parts in the ball piston engine thus thepower out put at the shaft is high.

In this engine the frictional losses are low and independentof operating speed in compare to conventional piston engine.

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DISADVANTAGES

Flow is choked during combustion due to high pressure differential and small clearance area

The friction and wear at the ball piston/cylinder wall sliding interface

Leakage through the ball piston/cylinder gap is a significant factor for engine efficiency at low speed

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APPLICATIONSIt can be applied to compressor.

The multi cylinder ball piston engine can beapplied to pump ,motor.

It can be applied to engine.

The wankle advanced two stroke ball pistonengine can be applied to land mover, standardmotor cycle and car and also for racing cars

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CONCLUSION The ball piston engine has potential for achieving higher

efficiency than piston internal combustion engines. Inaddition, subscale tests have shown that critical leakage andfriction characteristics are consistent with designassumptions.

The new design concept can be immediately applied tocompressor and pump applications in parallel with furtherengine development.

The material selection has been done in anticipation ofadditional subscale tests to extend the range of speed andduration of simulated operation..

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1.Richards,T.D.,"The Hanes Engine", informational report, copyright 1994. 2. Ashley, S.,"A New Spin on the Rotary Engine",Mechanical Engineering, April 1995, p80-82.3. Bloch, H.P.,"A Practical Guide to CompressorTechnology", McGraw-Hill, New York, 1996.4.http//google.com

REFERENCES

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Thank you