Page 231 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

• Main terminal post: There are two pegs protruding on the first and last cell of each battery, one of which
acts as negative and the other as positive terminal. By connecting battery wires to these main terminal posts,
electric current is supplied to other places. These pegs are also made of lead. It has been observed that the
chemical reaction of the battery causes the terminals of the battery wire to stick to its pegs. One should never
try to remove them by banging, but by pouring boiling water on them, they come out easily.

• Electrolyte: The battery plates are immersed in a solution of sulfuric acid in their respective cell containers.
The specific gravity of this solution ranges from 1.250 to 1.280. Suitable solution for battery is also available
ready otherwise it is made.
To make it, pure sulfuric acid and distilled water are used. It should be made in a glass, ceramic or plastic vessel
and keep in mind that the acid should be added to water, because if you add water to the acid, it will burn its small
body or clothes. This solution should be filled approximately 15 mm above the battery plates.
Dynamo: Dynamo is also known as generator. It converts mechanical energy into electrical energy. The dynamo
is mounted on the front of the engine, which is driven by a belt from the engine’s crankshaft. Therefore, dynamo
is used to fully charge the battery.
Main part of daynamo
1 frame 2 field coil 3 Armature 4 Throw bolt 5 ball bearings

6 commutator 7 carbon brush 8 fan pulley 9 poll shoe 10 side plate

A dynamo is a cylindrical body made of mild iron, which is constructed by closing both the ends of the frame
after inserting the armature between the poles along with the field coil. The front end cover is called driving end
bracket. Both ends are fixed with bolts.
The armature is supported at both ends of the ball bearing. A longitudinal slot is cut in its core, which provides
housing for the armature winding. To keep the dynamo cool, the front end of the armature is connected to a fan
pulley Is combined. This fan pulley is driven by a fan belt. The amateur is operated by this fan pulley between the
magnetic poles. The ends of the amateur leads are soldered to each segment of the commutator. The carbon
bushes are above the commutator segments. This segment receives energy and supplies it to the dynamo output
terminal. Thus the current flows to the battery through the control box.

Working principle of dynamo
In order for the dynamo to supply sufficient electricity for a long time without any fault, the following things should
be kept in mind.
• While servicing the dynamo, high grade Mobil oil should be poured into the bushes.

• The tension of the fan belt should be correct, so that it can rotate the dynamo without slipping.
• The bolts of dynamo foundation should be tightened properly.
• The terminal nut on the dynamo should be tightened properly.

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CITS : Automotive - Mechanic Diesel - Lesson 67 - 70