Engine Components
- 1. ASSIGNMENT#3 Suhail Ahmed BSAMT02161001 SEMESTER#03 AIRCRAFT ENGINES BS-AIRCRAFT MAINTENANCE TECHNOLOGY SUBMITTED TO :MR ZAWAR HYDER
- 2. Qno#1: What is magneto? Ans: An ignition magneto is a magneto that provides current for the ignition systemof a spark-ignitionengine, suchas a petrolengine. Itproducespulsesof high voltage for the spark plugs. The use of ignition magnetos is now confined mainly to engines where there is no other available electrical supply, for example in lawnmowers and chainsaws. It is also widely used in aviation piston engines even though an electrical supplyis usuallyavailable. Inthis casethe magneto's self-powered operation is considered to offer increased reliability. Because it requires no battery or other source of electrical energy, the magneto is a compact and reliable self- contained ignition system, which is why it remains in use in many general aviation applications. QNO#2: What is purpose of starter motor? Ans: The purpose of the starter motor is to start up the combustion engine. An electric motor forms the basis of the starter motor. When the starter switch is turned on, the starter relay turns on the electric motor. This motor drives the starter gear ring via the pinion gear. The rotating movement of the starter motor is created through the interaction of two magnetic fields. Starter motors come with permanent magnets or with electromagnets. Each of these configurations has its own specific characteristics. The energy required by the starter motor is provided by the battery. Thestarter motor requiresa lot of start-uppower.The battery must therefore have sufficient capacity and any losses must be kept to a minimum. As the starter motor begins to turn faster, start-up power is reduced. This is caused by the inverse voltage generated. Depending on temperature, diesel engines require starting assist systems. In case of passenger cars, these facilities consist of a preheating system that preheats the combustion chamber and the air it contains. Glow plugs serveas heating elements. The glow period is regulated using a glow timer.
- 3. Qno#3: Describe the components of Crankshaft? CRANK WEB: The arm of a crank which connects the shaft with the crank pin, or two adjacent crank pins. Crank web is also called crank arm. Crankpin: The cylindrical piece which forms the handle of a crank or to which a connecting rod is attached. Damper: A short heavy pendulum, in the form of pivoted balance weights, attached to the crank of a radial aero-engine in order to neutralize the fundamental torque impulses and so eliminate the associated critical speed. It is a Supplementary rotating mass driven through springs attached to a crankshaftat a point remote from the node to eliminate a troublesome critical speed. Gear Accessories: A gear or cogwheelis a rotating machineparthaving cutteeth, or cogs,which mesh with another toothed part to transmit torque. Geared devices can change the speed, torque, and direction of a power source. Gears almost always produce a change in torque, creating a mechanical advantage, through their gear ratio, and thus may be considered a simple machine. The teeth on the two meshing gears all have the same shape. Two or more meshing gears, working in a sequence, are called a gear train or a transmission. A gear can mesh with a linear toothed part, called a rack, thereby producing translation instead of rotation. Crank journal: The crank journalserveas the points of supportand as the center of rotation for the shaft. As bearing surfaces, themain journals and the connecting rod journals of crankshafts aresurface-hardened so thata longer wearing, more durable bearing metal can be used without causing excessive wear of the shaft.
- 4. Qno4: What is camshaft and its component? Ans:A camshaftin an internalcombustion enginemakes it possiblefor the engine's valves to open and close. The camshaft is a cylinder that aligns with the engine's cylinders. The asymmetrical lobes of the camshaft correspond to the engine's valves. As the camshaft rotates, it opens and closes the engine's valves. MainJournals The power created by the camshaftcomes fromconstant rotation. The main journals keep the camshaftin place as it spins around in the engine bay. Lobes While the camshaftspins, the lobes work in time with the motion of the piston. They open and close the intake and exhaust valves, and the pace in which they open and close the valves reflects on the vehicle's engine performance. The cam lobes change speeds when an engine changes speeds. Ends The front end of the cam secures the vehicle's timing belt and keeps it in time with the crankshaft. Therear end of the cam turns the distributor of the engine with a special gear. This part keeps the ignition timing in tune with the rest of the engine. Bearings Cam bearings are added parts used in conjunction with the main journals. The bearings help prevent the camshaftfromdamaging the engine block in the case of a malfunction in the engine. The bearings keep the camshaftin seamless rotation. Qno5: What is Camdrum? Ans: Cam drumoperates the valvemechanism of a radial engine .depending upon the number of rows of cylinders. In a single-row radial engine one ring with a double cam track is used. One track operates the intake valves; the other, the exhaust valves.
- 5. Qno6: What is GudgeonPin? Ans: The pin through the skirtof a piston in an internal combustion engine, to which the little end of the connecting rod is attached. The design of the gudgeon pin, especially in the case of small, high-revving automotive engines is challenging. The gudgeon pin has to operate under someof the highest temperatures experienced in the engine, with difficulties in lubrication due to its location, while remaining small and light so as to fit into the piston diameter and not unduly add to the reciprocating mass.