10-10-2012, 07:50 PM
i am manasa i am going to give a presentation on ball piston engine.so,tell me the constructional details and working of ball piston engine
10-10-2012, 07:50 PM
i am manasa i am going to give a presentation on ball piston engine.so,tell me the constructional details and working of ball piston engine
11-10-2012, 11:28 AM
hi friend you can refer these pages to get the details on BALL PISTON ENGINE
https://seminarproject.net/Thread-ball-p...ient-power https://seminarproject.net/Thread-ball-p...wer?page=2 https://seminarproject.net/Thread-ball-p...r?pid=3631
06-05-2014, 10:54 AM
Ball Piston Engine
INTRODUCTION The Ball Piston Engine is an extremely simple design, which has more in common with a ball bearing than a reciprocating engine, compressor or engine. Although the physics do become somewhat more complicated, they too can be explained in a more simple form. First, it should be understood that although it is easy to get lost in the geometry, there are only two different moving parts, therefore only two parts to be concerned with. The Ball piston Engine is unique in many ways. When configured as a turbine or air motor it is close to ideal. It is a positive displacement engine with continuous induction and rejection without continuity between the two events. It is capable of converting a fixed charge of 300+psi pressure at 1300+F and expanding that pressure charge and heat temperature, to atmospheric pressure at ambient temperature, extracting and converting all the pressure and heat energy induced, into mechanical rotational shaft power. The unique ball/dual track enables the ball piston and its respective cylinder to maintain perfect alignment throughout the complete 360 degrees of rotation. In theory, the ball piston moves in and out of the cylinder without touching the cylinder walls, unless called on to perform work. Using no more parts then a typical ball bearing, its ability to perform all the necessary functions of a two- stroke cylinder block, or positive displacement engine is amazing. The ball piston engine, having a relative reciprocating motion eliminates all reciprocating forces. The ball piston travels in a perfect circle in a cat and mouse fashion without having to come to a stop, and reversing its direction, typical of known reciprocating engines. IMPORTANT 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. The porting mechanism is achieved with simple port clocking within the rotor/internal stator bearing interface. Thus, part count is low and the hardware is simple in geometry, with only the rotor and ball pistons as moving parts. TECHNICAL CHALLENGES The main concerns for operation of the new machine are being addressed in focused subscale testing. First, leakage through the ball piston/cylinder gap is a significant factor for engine or compressor efficiency, especially at low speeds. Calculations show that the flow is choked during combustion due to high pressure differential and small clearance area. Choking is helpful in keeping leakage to acceptable levels. Engine efficiency predictions based on simple choked flow leakage models are very favorable. Leakage tests performed in subscale testing have shown that leakage is less than the simple models predict, and dependence on ball spin, pressure, and rpm have been and are being characterized. Second, the friction and wear at the ball piston/cylinder wall sliding interface is important. Engine performance depends on the magnitude of the effective friction coefficient, and high relative sliding speed can contribute to wear. Engine efficiency predictions based on an average friction coefficient of 0.1 or less are very favorable. Subscale tests have proven that the coefficient of friction for a silicon nitride ball piston on polished steel with no lubrication is about 0.075 +/- 0.03, about the same as estimated. SOME SALIENT FEATURES Friction is probably the most serious issue to address in engine design. Simply put, the rate of friction is dependent on the area of mass to mass contact, the force of mass to mass contact, and the duration (time) of contact. Time is seldom emphasized in friction equations, but I feel it is important to address. In the BP engine, the ball piston has a line contact at the cylinder wall and a two-point contact at the ball track on which the ball rolls. In theory, points and lines do not dimensionally exist. However, in the real world because of imperfect earthly materials, they do. |
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