Hydraulics Review

Question 1

What are 4 things hydraulic fluid does?

Answer 1

Seals tight tolerances
Cools moving parts
Transmits power
Lubes moving components

Question 2

What is viscosity?

Answer 2

Thickness of a fluid

Question 3

What does temperature do to the viscosity of the fluid?

Answer 3

Low temperature makes fluid thicker
High temperature makes fluid thinner

Question 4

What does AW stand for?

Answer 4

Anti- wear

Question 5

What does WR stand for?

Answer 5

Wear resistant

Question 6

What does EP stand for?

Answer 6

Extreme pressure additive

Question 7

Is 32 weight fluid thinner or thicker than 46?

Answer 7

Thinner

Question 8

What is cavitation?

Answer 8

Formation and collapse of air bubbles in the hydraulic fluid

Question 9

Best idea temperature for hydraulic fluid?

Answer 9

Between 80°F-120°F

Question 10

What is Pseudo cavitation?

Answer 10

Air leak drawing air into
The System

Question 11

Are fire resistant fluids fire proof?

Answer 11

No

Question 12

The temperature to which a fluid must be heated to give off vapor to ignite when a flame is applied?

Answer 12

Flash point

Question 13

When a fluid is heated up enough to burn after a flame is applied?

Answer 13

Fire point

Question 14

A fluid temperature at which it ignites without an external flame or spark

Answer 14

Auto ignition

Question 15

What allows water and oil to mix?

Answer 15

Water-oil emulsion

Question 16

What is phase separation?

Answer 16

When 2 fluids separate

Question 17

What do you add to fluid in a low temperature environment to keep from freezing?

Answer 17

Water -glycol

Question 18

What are some problems with synthetic fire resistant fluids?

Answer 18

Harmful to seals
Harmful to protective coatings
Foaming and air retention
Dirt retention

Question 19

How should you store a drum or oil?

Answer 19

Somewhere warm
Store on its side
Remove dirt and debris from the lid before opening the lid up

Question 20

What do hydraulic pumps do?

Answer 20

Convert the mechanical energy transmitted by its prime mover.

Question 21

How do vane pumps work?

Answer 21

Draws in fluid as volume increases, fluid leaves pump as volume decreases

Question 22

5 components of a vane pump?

Answer 22

Vanes, ring, shaft, rotor and a port plate

Question 23

What does a fixed displacement pump need to operate?

Answer 23

Relief valve

Question 24

How to control system pressure with a variable displacement pump?

Answer 24

Pump compensator

Question 25

To have fluid flow volume must do what?

Answer 25

Volume must change

Question 26

What is an issue with an unbalanced pump?

Answer 26

Thrust loading

Question 27

What pump eliminates thrust loading issues?

Answer 27

Balanced pump

Question 28

Advantage to cartridge style pumps?

Answer 28

Easy pump servicing

Question 29

All variable volume and Pressure compensated pumps must have?

Answer 29

Case drain

Question 30

How does a gear pump work?

Answer 30

Generates a pumping action by causing gears to mesh and unmesh

Question 31

Name 5 types of pumps?

Answer 31

Vane Gear Double Geroter Piston

Question 32

What would a flow meter on the case drain tell you?

Answer 32

If the flow goes up then that is a sign of the pump wearing out

Question 33

Where does a case drain go?

Answer 33

Back to tank

Question 34

What does a pump do?

Answer 34

Pulls fluid in the large volume area and pushes out the smallest volume area

Question 35

What do motors do?

Answer 35

Pulls fluid in the smallest volume area and leaves at the largest volume area

Question 36

Pressure equals?

Answer 36

Torque (force)

Question 37

Flow equals?

Answer 37

RPM (speed)

Question 38

Can all motors be pumps?

Answer 38

Yes

Question 39

Can all pumps be motors?

Answer 39

No

Question 40

Hydraulic motors are what style pumps?

Answer 40

Positive displacement

Question 41

What are 5 hydraulic motors advantages

Answer 41

Instant reversing of motor shaft Can be stalled without motor damage Torque control throughout is operating speed Dynamic braking easily accomplished HP to weight ratio is better compared to electric motors

Question 42

Regardless of pressure motor speed will?

Answer 42

Remain constant

Question 43

How do you set a pressure compensator and relief valve?

Answer 43