1. Engine Lubrication System

2. Step I. Duty Report Step II. Review Review what they learnt in the last class The purpose of using a cooling system two different types and their main differences Recite the new words Step III. Reading material Ask the students read the whole text and get the main idea Discuss about the text

3. Engine Lubrication System Step IV. Engine Lubrication System New words: Check the pronunciation of the new words main usage of the words Text: We can reduce friction to a considerable degree by the use of lubrication oil.

4. Engine Lubrication System Dry frictionBoundary frictionLiquid friction Types of friction

5. Engine Lubrication System lubrication oil: the four main function  a protective coating  absorb and carry the heat  wash off dirt  absorb shocks

6. Engine Lubrication System What’s lubrication oil made from? Two types of engine lubricating systems  splash  pressure/force feed  combination of the two types main function (passage 8) main units (passage 9-17)

7. Engine Lubrication System Splash lubrication （飞溅润滑） Pressure lubrication （压力润滑） Grease lubrication （ 润滑脂润滑）

8. Engine Lubrication System Step V. Exercise Ask the students translate some passages Ask the students describe the main units of the lubrication system, and their main functions