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.
