The document is a seminar presentation on the ball piston engine. It includes sections on the introduction, mode of operation, design features, material selection, working, lubrication, advantages, disadvantages, applications, and conclusion of the ball piston engine. The ball piston engine uses two intertwined rotors instead of reciprocating pistons, where spherical pistons rotate in a spherical housing with slightly inclined rotational axes to create "strokes" and volume changes in the working chambers. It has potential for higher efficiency than piston engines due to lower friction and more power extraction on the power stroke.

1. VISVESVARAYA TECHNOLOGY UNIVERSITY
BELGUM
NEW HORIZON COLLEGE OF ENGINEERING
SEMINAR
ON
BALL PISTON ENGINE
DEPARTMENT OF MACHINE DESIGN
PRESENTED BY
SHARATH KUMAR H A
1NH14MMD14
Mtech ,1st sem,
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2. CONTENTS
1. INTRODUCTION
2. MODE OF OPERATION
3. DESIGN FEATURES
4.MATERIAL SELECTION
5.WORKING OF ENGINE
6. LUBRICATION
7.ADVANTAGES
8. DISADVANTAGES
9. APPLICATION
10.CONCLUSION
11.REFERENCES
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3. INTRODUCTION
• The Ball piston engine (Wolf hart engine) is an
[[internal combustion engine /internal combustion]]
rotary engine that uses two interwinded rotors instead
of reciprocating pistons.
• A spherical piston rotates in combination with a
spherical housing, whereby the rotational axes incline
towards each other slightly.
• In these way “strokes” are created within the rotational
system generating periodic volumetric changes in the
working chambers adjacent to the dividing wall
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4. MODE OF OPERATION
• The ball pistons rolling on an eccentric track. The
balls exert tangential force on the cylinder walls
which turn the rotor.
• The useful power is available at the rotor output
shaft.
• The combustion chambers are within the spinning
rotor. Chamber porting for intake, compression,
power, and exhaust strokes is achieved by passage
of the chamber tops across an internal stator with
appropriate feeds as the rotor spins.
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5. 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 with
porting, implements the four strokes of the Otto
cycle.
• However, there are a number of features that make
this engine design favorable for high efficiency and
emissions control.
• The porting required for four stroke operation is
achieved with no additional moving parts, and no
valve train losses
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6. MATERIAL SLECTION
• A series of tests to characterize friction and wear of various
materials in a simulated ball piston engine/compressor were
performed to aid in selection of production materials.
• Another goal of the tests was to explore this machine could
run without lubrication.
• If un lubricated operation was not possible, tests with
instrumentation would be used to confirm the lubricated
operation of the machine and the resulting internal loads.
• Friction at conventional piston rings, piston pin, and
connecting rod/crankshaft bearing are eliminated ). The
rotor/stator bearing is of a gas or fluid hydrostatic type, so
friction is very low at that site
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7. WORKING OF ENGINES
(SUCTION STROKE)
Beginning at top dead
center (TDC) at 0 degrees
rotation, the stator intake
passage is open to the
cylinder and a fuel/air
charge is pulled into the
cylinder as the ball piston
moves radially outward for
the first 90 degrees of
rotation .
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8. WORKING OF ENGINE
(COPRESSION STROKE)
Then the intake
passage is closed off,
and the ball reverses
radial direction for the
next 90 degrees of
rotation, during which
time the new charge is
compressed
(compression stroke).
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9. WORKING OF ENGINE
(POWER STROKE)
Just past 180 degrees rotation, the
compressed charge is ignited as the
cylinder port passes a small ignitor
port. Combustion ensues, and the high
combustion pressure pushes radially
outward on the ball piston for the next
90 degrees of rotation. The ball in turn
pushes tangentially on the cylinder
wall because of the "slope" of the
eccentric ball track, which is now
allowing the ball to move radially
outward. The tangential force
produces useful torque on the rotor
(power stroke
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10. WORKING OF ENGINE
(EXHAUST STROKE)
At 270 degrees of rotation,
the spent combustion charge
is allowed to escape through
the exhaust passage as the
cylinder port is uncovered.
Exhaust is expelled as the ball
moves radially inward for the
next 90 degrees of rotation
(exhaust stroke). Then the
cycle repeats.
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11. LUBRICATION
As is the case with a standard four-stroke engine, an oil bath
is situated behind the piston, which in turn is fitted with oil
scraper rings
. Here attention must merely be paid to ensuring that the oil
gathers externally, because of the rotation. In fact, if outlet ports
are placed in this area for the oil, an oil pump can be potentially
dispensed .
Otherwise, oil that is pumped into the center also carries heat
from the interior to the exterior,which in turn can be utilized
for cooling purposes
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12. ADVANTAGES
The stroke magnitude and rate can be different for different stroke
in cycle so that it provides the possibility of converting more energy
to the shaft power by greater expansion during the power stroke.
It has ability (i.e. in multi energy domain engine) to complete any
even numbers of strokes per revolution in single rotation of rotor
There is no much moving parts in the ball piston engine thus the
power out put at the shaft is high.
In this engine the frictional losses are low and independent
of operating speed in compare to conventional piston engine.
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13. 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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14. APPLICATIONS
It can be applied to compressor.
The multi cylinder ball piston engine can be
applied to pump ,motor.
It can be applied to engine.
The wankle advanced two stroke ball piston
engine can be applied to land mover, standard
motor cycle and car and also for racing cars
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15. CONCLUSION
 The ball piston engine has potential for achieving higher
efficiency than piston internal combustion engines. In
addition, subscale tests have shown that critical leakage and
friction characteristics are consistent with design
assumptions.
 The new design concept can be immediately applied to
compressor and pump applications in parallel with further
engine development.
 The material selection has been done in anticipation of
additional subscale tests to extend the range of speed and
duration of simulated operation..
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16. REFERENCES
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 Compressor
Technology", McGraw-Hill, New York, 1996.
4.http//google.com
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17. Thank you
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