Lubrication&Cooling Lec

8/4/2019 Lubrication&Cooling Lec

1/36

Engine Lubrication And Cooling

System


2/36

Lubrication System Description

(1/2)

Camshaft timing oil control valve

Main oil gallery

Oil return hole

Oil pressure switch

Oil filter

Oil strainer

Oil pump


3/36

Lubrication System Description

(2/2)

Main oil gallery

Oil filter

Oil cooler

Oil pump

Oil strainer

Crankshaftjournal

Connectingrod

Oil jet

Piston

Oil jet

Timingchain

Chaintensioner

Cylinder head

Camshaft timingoil control

valve filter

Intakecamshaft

journal

Exhaustcamshaft

journal

Camshaft timingoil control valve

VVT-icontroller

Oil pan

Oil flow circuit for 1NZ-FE engine

The oil cooler, outlined with a dotted line, basically is not used on the 1NZ-FE engine.Here is listed to understand the position of the oil cooler in the flow.


4/36

Functions Of Lubricating Oil

Engine Lubricating oil performs the following functions:

Minimizes wear

Reduces friction and power loss

Removes heat Reduces engine noise

Forms a seal

Cleans


5/36

Lubrication System Oil Pump

(1/1)

Drive roter

Driven roter

Relief valve


6/36

Gear Pump


7/36

Crescent Pump


8/36

Rotor Pump


9/36

Lubrication Of Cylinder

When a hole in the connecting rod aligns with a hole in the

crankpin, oil is sprayed onto the cylinder wall to lubricate

the piston and rings.


10/36

Oil Coolers

Oil coolers are heat exchangers, in which heat in the oil is

transferred either to the engine coolant or to the atmosphere.

There are two designs of oil coolers:

1. Oil-to-Coolant Oil Coolers Oil and coolant flow through this type of cooler the two being separated by tubes or

baffles of some type. Oil through the oil gallery passes through the oil cooler before itenters the filter, so that oil leaving the filter has been both cooled and filtered. Thecooler has external connections for the coolant hoses that connect it to engines coolingsystem.

2. Oil-to-Air Oil Coolers

This type of oil cooler is similar to a radiator in that it has tubes and fins. Oil from thelubrication system is circulated through the cooler, and air is directed across the tubesand fins. In this way, heat is removed from the oil and is temperature is reduced. Thecooler is located in the engine compartment where it will get an adequate flow of air,usually near the radiator.


11/36

Motor Oil Viscosity Grades

When you see a W on a viscosity rating it means that this oil viscosity has

been tested at a Colder temperature.

The numbers without the W are all tested at 210 F or 100 C which is

considered an approximation of engine operating temperature.

The difference is when the viscosity is tested at a much colder temperature.For example, a 5W-30 motor oil performs like a SAE 5 motor oil would

perform at the cold temperature specified, but still has the SAE 30 viscosity

at 210 F (100 C) which is engine operating temperature.

This allows the engine to get quick oil flow when it is started cold verses

dry running until lubricant either warms up sufficiently or is finally forcedthrough the engine oil system. The advantages of a low W viscosity number

is obvious. The quicker the oil flows cold, the less dry running. Less dry

running means much less engine wear.


12/36

Motor Oil Viscosity Grades

This allows the engine to get quick oil flow when it is started cold verses

dry running until lubricant either warms up sufficiently or is finally forced

through the engine oil system. The advantages of a low W viscosity number

is obvious. The quicker the oil flows cold, the less dry running. Less dry

running means much less engine wear.

The SAE viscosity rating was based on how quickly a specific quantity of

motor oil flowed through a test orifice when heated to operating

temperature (100 C or 212 F).

Any oil that took from 5 to 14 seconds to flow would be SAE 10.

Oil that would take 15 to 24 seconds would be labeled as SAE 20. Oil that took 25 to 34 seconds would be SAE 30.

And so on until SAE 50.


13/36

Lubrication System Oil Filter

(1/1)

Check valve

Element

Relief valve

Oil flow (in)

Oil flow (out)

Oil flow if the relief valve open


14/36

Lubrication System Oil Pressure Warning Lamp

(1/1)

1.When the oil pressure is low[19.6 4.9 kPa (0.2 0.05kgf/cm2) or lower]/

2.When the oil pressure is high[19.6 4.9 kPa (0.2 0.05kgf/cm2) or higher]

Oil pressure warning lamp

Low engine oil level warning lamp

Oil pressure switch

Oil pressure(Normal)

ECU

Warning lamp

Oil temp. switch

Oil level sensorOil pan

Oil level(Normal)

Warning lamp

Oil


15/36

Lubrication System Oil Pressure Warning Lamp

(1/1)

1.When the oil pressure is low[19.6 4.9 kPa (0.2 0.05kgf/cm2) or lower]/

2.When the oil pressure is high[19.6 4.9 kPa (0.2 0.05kgf/cm2) or higher]

Oil pressure warning lamp

Low engine oil level warning lamp

Warning lamp

Oil pressure switch

Oil pressure(Low)

ECU

Warning lamp

Oil temp. switch

Oil level sensorOil pan

Oil level(Low)

Oil


16/36

Lubrication System Oil Cooler

(1/1)

Water bypass hose

Oil cooler

Oil filter

Engine coolant

Oil cooler

Oil filter

From Oil pump

to Main oil gallery

Relief valve


17/36

Lubrication System Oil Consumption

(1/1)The gap between the cylinder and the pistonThe gap between the valve guide bushing and valve stem

Loss due to oil contained in blow-by gas

PCVvalve


18/36

Cooling System

Main parts of the basic cooling system are

Radiator

Water Pump

Water Jackets

Radiator Hoses

Thermostat

Fan Coolant


19/36

Cooling System


20/36

Cooling System


21/36

Cooling System

(1/1)

to Radiator

from Heater core

from Radiator

Bypass passage Cylinder head

Water pump

Thermostat

Cylinder blockThrottle body

Radiator

Heater core

to Heater coreto Throttle body


22/36

Mechanisms For Heat Transfer

Heat is transferred by means of

Conduction

Convection Radiation


23/36

Types of Radiators

There are two types of radiators

Cross flow radiators

Vertical flow radiators


24/36

Vertical Flow Radiator

Radiators first used downward vertical flow, driven solely by a

thermosyphon effect.

Coolant is heated in the engine, becoming less dense and so rising, cooled,

denser coolant in the radiator falling in turn. This effect is sufficient for

low-power stationary engines, but inadequate for all but the earliest

automobiles.

A common fallacy is to assume that a greater vertical separation between

engine and radiator can increase the thermosyphon effect.

Once the hot and cold headers are separated sufficiently to reach their

equilibrium temperatures though, any further separation merely increasespipe work length and flow restriction.


25/36

Vertical Flow Radiator


26/36

Cross Flow Radiator

A cross flow radiator has a tank at each side.

They are radiators that have been turned on their side to reduce the overall

height.

The coolant flows horizontally.


27/36

Working of Radiator

Typical Automotive Radiators are forced air-cooled cross-flow heat

exchangers.

At the hot side, the hot coolant is forced to flow downwards through thevertical tubes or from one side of the radiator core to another through the

horizontal tubes.

At the cold fluid side, atmospheric air is forced to flow across the fined

tubes to remove the heat from the coolant.


28/36

Working of Radiator


29/36

Cooling System Flow of Engine Coolant

(1/1)

1.Thermostat in water inlettype (With bypass valve)


30/36

Cooling System Thermostat

(1/1)

With bypass valve Without bypass valve

Main valve

Cylinder

Bypass valveWax

Main valve

Jiggle valve

Jiggle valve

WaxCylinder


31/36

Cooling System Water Pump

(1/1)

V-ribbed belt Bearing Mechanical seal

Cylinderblock

Swirl

chamber

Rotor

Water pump pully Water drain hole


32/36

Cooling System Electric Motor-driven Cooling Fan

(1/2)

1.Outline

Cooling fan

Fan motor

Water temperature switch


33/36

Cooling System Electric Motor-driven Cooling Fan

(2/2)

2.Operation

Fan relayIgnition switch

Coolanttemp. switch

Coolant temperature


34/36

Cooling System Temperature-controlled Fluid Coupling

(1/2)

1.Overview

Pulley

Fluid coupling

Cooling fan

Air hot Air warm Air cold

Bimetal spring

Bimetal plate

Front operating chamber

Rear operating chamber

Silicone oil


35/36

Cooling System Temperature-controlled Fluid Coupling

(2/2)

2.OperationWithout coupling

Fan

speed

Air hot

Air warm

Air cold

0

Air Temperature (HOT) during low speed drivingAir temperature (HOT) during high speed drivingAir temperature (WARM) during high speed driving

Air temperature (COLD) during high speed driving

Fluid coupling shaft speed


36/36

Cooling SystemElectronically Controlled Hydraulic Cooling Fan System

(1/1)

Condenser

Radiator

Cooling fan

Hydraulicmotor

Solenoidvalve

Hydraulicpump

Reservoir

Oil cooler

Water pump. sensor signal,Air conditioner signal,Engine speed signal

ECU

Lubrication&Cooling Lec

Documents

Transcript of Lubrication&Cooling Lec