Prime Movers for Agricultural Machines PDF

Prime Movers for Agricultural Machines Major Power Sources Internal Combustion Engine Single-cylinder and multi-cylinder engines Spark-ignition and Compression-Ignition engines Electric Motor AC and Dc motors Internal Combustion Engine...

Prime Movers for Agricultural Machines Major Power Sources Internal Combustion Engine Single-cylinder and multi-cylinder engines Spark-ignition and Compression-Ignition engines Electric Motor AC and Dc motors Internal Combustion Engine Compression Ignition A heat engine that burns fuel and air inside a combustion chamber located within the engine b. Vertical shaft – The drive shaft is vertical proper. A machine use to power tractors, combine position while the piston is in sideward harvesters, and other self-propelled equipment position Classifications of ICE Basic Components of the Main Engine System (1) According to Ignition a. Spark-Ignition Engine - uses a spark to 1. Cylinder Head – It houses the valves, spark plug or ignite fuel Gasoline is use as fuel fuel injector, and serves as cover of the cylinder block 2. Cylinder Block – It encloses the piston and confines b. Compression-Ignition Engine - Uses high the expanding gases compression to raise the temperature of 3. Valves – It allows the flow of fuel, air, or exhaust the air in a chamber and ignites the gases injected fuel without spark Diesel is use 4. Piston - It is a hollow cylinder with closed top upon as fuel which the expanding gases act and transmit force to the crankshaft (2) According to Number of Stroke 5. Crankshaft – It receives power from the piston and a. Two-Stroke Cycle Engine - Produces transmit it to the other parts to do useful work power in one revolution of the crankshaft 6. Piston Rings (compression and oil rings) – it retain b. Four Stroke Cycle Engine - Produces compression, reduce cylinder wall contact thereby power in two revolutions of the crankshaft reducing friction losses and wear (3) According to Number of Cylinders 7. Piston pin – it joins the connecting rod and the piston a. Single -Cylinder One piston 8. Flywheel – it is the energy storage device of the b. Multiple -Cylinder More than one engine to keep it at uniform speed when the piston (3, 4, 6, 8, 12) crankshaft is not receiving power to the piston (4) According to the Position of Drive Shaft 9. Crankcase – it encloses and supports the crankshaft a. Horizontal Drive Shaft – Drive shaft is in and serves as reservoir for the lubricating oil horizontal position while the piston is upward position Terminologies Electric Motor 1. Bore – size of the opening of the cylinder almost -Electric motors are machines that converts electrical energy equal to the diameter of the piston plus the rings to mechanical power by producing rotational motion and 2. Stroke – distance traveled by a piston from the TDC torque. to the BDC 3. Top Dead Center (TDC) – the uppermost position of Use of Electric Motor the piston during the compression and exhaust stroke 1. Pumping of Water 4. Bottom Dead Center (BDC) – the lowest most 2. Driving Grain Milling Equipment position of the piston during the intake and power 3. Driving Size Reduction Equipment stroke 4. Driving Material Handling Equipment 5. Engine Displacement (PD) – volume displaced by a 5. Driving various food equipment piston in one stroke 6. Clearance Volume (CV) – volume in the combustion cylinder when the piston is at the TDC position 7. Compression Ratio (CR) – ratio of the total volume to the clearance volume 8. Mean Effective Pressure (MEP) – amount of pressure generated during the power stroke of the engine 9. Revolution – one complete rotation of the crankshaft 10. Cycle – series of event occurring one after the other in a definite order and repeats the event after the last one has occurred 11. Firing Order – The sequence of piston power in multiple cylinders in delivering the power stroke 12. indicated Horsepower – the power generated at the combustion chamber 13. Brake Horsepower – power available at the drive shaft or the crankshaft of an engine 14. Friction Horsepower – power loss due to friction of piston and other component parts of the engine 15. Rated Horsepower – power as specified by the manufacturers Cycles of Events Intake Stroke – fuel and air or air alone is suck in the combustion chamber as the piston moves in downward direction Compression Stroke – fuel and air or air is compressed by the piston as it moves in upward direction Power Stroke – fuel and air is ignited to produce power at the downward movement of the piston and transmitted it into the crankshaft of the engine Exhaust Stroke – burn fuel and gases is discharged from the combustion chamber