Pistons.ppt
- 1. PRESENTATION ON PISTON BY SURENDRA KUMAR PATEL JE (E&M) Course Srl No 07 158 FCPL/71 rcc/24 tf/(p)PUShPAK
- 2. Pistons
- 3. INTRODUCTION : PISTON IS ONE OF THE MAIN PART OF ENGINE. WHICH IS SUBJECTED TO ENORMOUS THRUST CAUSED BY BURNING OF FUEL AND TRANSMITTING THIS THRUST TO THE ROTARY MOTION OF CRANK SHAFT. THESE ARE MOSTLY MADE OF ALUMINUM ALLOY. TO
- 4. AIM : (1) PROVIDES CLOSED CHAMBER TO GASES TO BURN. (2) SUCKS AIR DURING SUCTION STROKE. (3) COMPRESS AIR DURING COMPRESS STROKE. (4) IT A MEDIUM TO TRANSFER HEAT ENERGY TO CRANK
- 5. FUNCTION OF PISTON : (1) WHEN THE PISTON MOVES FORM TDC TO BDC IN SUCTION STROKE IT PRODUCES A PARTIAL VACUUM DUE TO WHICH FRESH CHARGE IS SUCKED IN I.E WORKS AS PUMP FOR TAKING AIR IN THE CYLINDER. (2) SOME OF THE PISTON HAVE COMBUSTION CHAMBER MADE IN
- 6. PRODUCED IN THE POWER STROKE TO CRANK SHAFT. (4) IN EXHAUST STROKE IT PUSHED OUT EXHAUST GASES. (5) IT WORK AS A GUIDE FOR THE UPPER PART OF CONNECTING ROD. (6) IT CARRIES RING WHICH SEAL COMBUSTION FROM SUMP.
- 7. PARTS OF PISTON (A) HEAD (B) SKIRT (C) RING GROOVE (D) RING LAND (E) GUDGEON PIN BOSS
- 9. Piston Construction Piston head – Round – Approx. .040 undersized Ring grooves Ring lands Drain holes and slots Wrist pin boss
- 10. HEAD : IT IS THE UPPERMOST PARTS OF PISTON WHICH IS SUBJECTED TO HOT BURNING GASES WITH TEMPERATURE AND PRESSURE. SKIRT : SKIRT OF LOWER PART OF PISTON AND WORKS AS A GUIDE FOR THE PISTON SO THAT IT MOVES STRAIGHT IN THE CYLINDER. RING GROOVE : GROOVE ARE MADE IN THE PISTON TO ACCOMMODATE COMPRESSION AND OIL RING GROOVE
- 11. RING LAND : THE SPACE LEFT IN THE CIRCUMFERENCE OF PISTON AFTER CUTTING RING GROOVE IS CALLED RING LAND. GUDGEON PIN BOSS : THE PLACE WHERE GUDGEON PIN IS FIXED IN THE PISTON IS KNOWN AS GUDGEON PIN BOSS AND IS USUALLY REINFORCED. THIS IS ALSO KNOW AS WAIST PIN AND IS USED TO CONNECT PISTON WITH CONNECTING ROD. IT IS MADE OUT OF STEEL ALLOY AND HOLLOW FROM INSIDE SO THAT IT IS LIGHT WIGHT AND AT THE TIME,
- 12. CLEARANCE OF PISTON : FOR THE COST IRON PISTON KEEP CLEARANCE 0.0007” (0.018 MM) PER INCH DIA. OF PISTON AND FOR ALUMINUM ALLOY PISTON KEEP 0.001” (0.025 MM) PER INCH DIA OF PISTON.
- 13. PISTON RING : PISTON RING ARE USED IN PISTON TO MAINTAIN GAS TIGHT SEAL BETWEEN THE PISTON AND CYLINDER. PISTON RING MOSTLY MADE OUT OF CAST IRON. PISTON RING IS TWO TYPE. (A) COMPRESSION RING
- 14. Piston Construction Materials – Cast iron (used in very old engines) – Cast aluminum (most common) – Forged aluminum – Hypereutectic alloys (high silicon content aluminum) – Carbon Graphite (being tested)
- 15. Piston Construction Piston Pin Offset – The piston pin is offset towards the major thrust side of the piston to reduce piston wear, and piston noise – The major thrust side is the side that is loaded during the power event – The minor thrust side is the side loaded during the compression event
- 17. Piston Direction Pistons should be positioned so arrow, dot or other marking faces the front of the engine (except reverse rotation engines)
- 18. Piston Head Design Pistons may have a dished, flat or domed design
- 19. CONCLUSION : PISTON IS VERY IMPORTANT PARTS OF ENGINE. WITHOUT PISTON IT IS NOT PASSABLE TO FORM A ENGINES. PISTON IS A BACK BONE OF ENGINE.
- 20. THANKS YOU