Page 151 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

MODULE 6 : Engine Lubricating System

LESSON 39 - 46: Engine lubrication system Lubricant,
types, application and its properties.

Study about lubrication systems and

its components such as oil sump, oil
strainer, oil pump, relief valve, filter,

bypass valve, oil cooler etc

Objectives

At the end of this lesson you shall be able to
• define Engine lubrication system.
• explain types of lubricants and properties of lubricants
• identify and locate differents parts of lubrication systems.

Lubricant, type, application, and its properties
Lubricants: - lubricants are substances typically used to reduce friction between parts in contact. Depending
on the type, lubricants also perform various other functions such as heat regulation, power transmission, sealing
against dust or dirt, as well as reducing oxidation and preventing corrosion. Lubricants are typically in liquid or
semi-solid form, but they may exist in different forms.
Types of lubricants
Lubricants are mainly of following three types:
1 Liquid lubricants

2 Semi-solid lubricants
3 Solid lubricants
1 Liquid Lubricants: Liquid state lubricants are not fixed in size, so they can be transported by flowing from one
place to another. Due to this quality, they are used the most. The following four types of oils are used as liquid
lubricants.
i Mineral oil: Mineral oil, is extracted from petroleum. These oils are waxy (paraffin) and naphthenic. Waxy
oils are more stable at higher temperatures because they contain a large amount of wax dissolved in them,
which gives the oil more stability at higher temperatures than naphtha-based oils.
These are of the following types
* Circulating oil
* Gear oil
* Mobil, oil or engine oil

* Refrigeration grade oil
* Spindle oil
* Steam cylinder oil
* Wire rope oil
Gear oil and Mobile oil are mainly used in modern engines, which are described below
Gear Oil (Gear Oil) Gear oil is a light thick oil, which is used in the gear box, steering and differential parts of
vehicles. SAE 90 gear oil is used in gear box and SAE 140 gear oil is used in other parts.

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