Lubrication system

Question 1

What type of bearings support the rotor in a turbine engine?

Answer 1

Roller and ball bearings

Question 2

What are the seven functions that oil performs in an engine?

Answer 2

-Friction reduction
-Seals
-Cushions
-Removes heat
-Cleans engine
-Protects against corrosion
-Performs hydraulic action

Question 3

What is a dry-sump system?

Answer 3

Oil supply is in an external tank

Question 4

What is a wet-sump system?

Answer 4

Oil supply is in the engine itself

Question 5

What sup system is most common on turbine engines?

Answer 5

Dry-sump

Question 6

What is a hot tank system?

Answer 6

Hot oil is returned to the tank by the scavenge pump. The oil cooler is located after the pressure pump-in the pressure system.

Question 7

What is a cold tank system?

Answer 7

Hot oil is moved by the scavenge pump through an oil cooler before it returns to the storage tank. The oil cooler is in the scavenge system.

Question 8

What are the three subsystems in a turbine engine lubrication system?

Answer 8

-Pressure
-Scavenge
-Vent

Question 9

What is the pressure subsystem?

Answer 9

Supplies the correct amount of clean oil at the proper pressure and temp to all the bearing and gears.

Question 10

What is the scavenge subsystem?

Answer 10

Picks up oil after it has performed its lubrication and cooling functions and returns it to the oil tank where it can be recirculated through the system.

Question 11

What is the vent subsystem?

Answer 11

Provides slight oil pressure to oil in the tank, assuring a positive flow of oil to the pump inlet preventing pump cavitation.

Question 12

Two types of seals on turbine engine shafts?

Answer 12

-Carbon seals
-Labyrinth seals

Question 13

What is a pressure pump?

Answer 13

Takes oil from the storage tank and supplies it under pressure to the bearings and gears in the AGB

Question 14

What is a scavenge pump?

Answer 14

Transfers oil from the sumps to the storage tank.

Question 15

What are three types of oil screen/filters?

Answer 15

-Wire mesh
-Screen disk
-Pleated fiber

Question 16

What are the 4 bases of lubricants?

Answer 16

-Animal
-Vegetable-base
-Mineral
-Synthetic

Question 17

What condition has the greatest effect on viscosity?

Answer 17

Temperature

Question 18

What is the viscosity index?

Answer 18

The change in the oil’s viscosity for a given change in temp.

Question 19

What type of oil is used on engine break in?

Answer 19

Straight mineral oil

Question 20

What type of oil is used after break ins?

Answer 20

Ashless-dispersant

Question 21

What are the two ways reciprocating engines carry their oil supply?

Answer 21

Wet sump and dry sump system

Question 22

What type of engine lubrication system uses a scavenger pump?

Answer 22

Dry sump

Question 23

In a dry sump system, what is used to prevent oil from running back in the engine cranckcase when the engine isn’t running?

Answer 23

A check vavle

Question 24

Why do reciprocating engine constant-displacement oil pumps require a relief valve?

Answer 24

Constant-displacement pumps always move ore oil than the engine needs. To keep the oil pressure at a more constant level

Question 25

What is a bypass valve?

Answer 25

To allow oil to flow through the engine if the oil filter is clogged.

Question 26

In an oil cooler, what controls the flow of oil through the cooler core?

Answer 26

A thermostatic flow control valve

Question 27

Why are dry-sump oil tanks required to have 10% more space that capacity?

Answer 27

-Hot oil expands
-Foam

Question 28

What are the two oil indicating instruments required by the FAA for all recip eninges?

Answer 28

-Oil temp
-Oil pressure