Fundamentals

Question 0

Flow rate?

Answer 0

Volume of fluid passing a point in a period of time. Created by difference in pressure.
GPM- gallons per minute
L/min- litres per minute

Question 1

Actuator?

Answer 1

A device that converts hydraulic power into mechanical power.
Ex. Cylinders, hydraulic motor

Question 2

Fluid?

Answer 2

Any substance that flows.

Both gases and liquids are fluids

Question 3

Force?

Answer 3

A push of pull

Pounds, or newtons

Question 4

Hydraulics?

Answer 4

Engineering science that pertains to the transmission of force and or motion through a fluid medium

Question 5

Hydrodynamics?

Answer 5

Force by using motion through a fluid medium

Typically high flow rate, low pressure

Question 6

Hydrostatics?

Answer 6

Force using motion of confined liquids.

Typically high pressure, low flow rate

Question 7

Mass?

Answer 7

Amount of material in a object
Pound or slug
Gram or kilogram

Question 8

Orifice?

Answer 8

A device to create restriction to flow. Causes pressure drop

Question 9

Power?

Answer 9

Amount of work done in a given period of time
Hp- horsepower
W- watt

Question 10

Pressure?

Answer 10

Force per unit area.
(PSI)
Pascals (PA)

Question 11

Pump?

Answer 11

Converts mechanical power into hydraulic power (pressure and flow)

Question 12

Torque?

Answer 12

A twisting force

Question 13

Vacuum?

Answer 13

The absence of pressure. Total absence of pressure is known as perfect vacuum.

Question 14

Partial vacuum?

Answer 14

Pressure that is les then atmospheric but not a perfect vacuum

Question 15

Velocity?

Answer 15

Describes rate of motion (Speed).
Linear: feet per second (ft/sec) or meters per second (m/sec)
Rotational: revolutions per second (RPS)

Question 16

Volume?

Answer 16

Internal capacity of a space or chamber.
Cubic inches, gallons (in^3, gal.)
Cubic centimetre, litres (cm^3, L)

Question 17

Work?

Answer 17

Product of force acting through a distance.
Foot pounds, inch pounds (ft-lb, in-lb)
Newton meters (N•m)

Question 18

What are 5 scales of pressure measurement?

Answer 18

Gauge pressure
Absolute pressure
Imperial units of pressure
Inches of mercury 
Metric units of pressure

Question 19

Gauge pressure measurement?

Answer 19

Ignore atmospheric pressure. The measuring device is calibrated to read 0 when exposed to atmospheric pressure.

Question 20

Absolute pressure measurement?

Answer 20

Includes atmospheric pressure. Calibrated to read zero in a perfect vacuum. Pressure measurements have “a” suffix attached.

Question 21

What is a bar equal to?

Answer 21

1 bar = 100000 Pa = 100 kPa = 14.50 psia

Question 22

What is the “atmosphere” unit equal to?

Answer 22

1 atm = 1.01 bars = 101.34 kPa = 14.7 psi

Question 23

On a hydraulic schematics what do each of the following represent?
Circle, square, diamond, rectangle

Answer 23

Pumps, motors
Valves
Filters, heat exchangers
Cylinders

Question 24

What are each of the ports on a hydraulic valve schematic labeled as?

Answer 24

``` A= outlet/work port B= outlet/work port P= pump, pressure T= tank ```

Question 25

What is a prime mover?

Answer 25

A device that supplies energy to power the hydraulic system. | Commonly engines, an be electric motors as well

Question 26

What is purpose of a filter in hydraulic system?

Answer 26

Remove contamination from oil. | Has dotted line across diamond on schematic

Question 27

What is purpose of a heat exchanger?

Answer 27

Coolers remove heat from hydraulic oil. | Heaters add heat energy to hydraulic oil.

Question 28

How are heat exchangers shown on schematic?

Answer 28

Diamond with solid line across it. Arrows point to show whether it adds or removed heat

Question 29

Pascals law

Answer 29

Pressure applied to a confined liquid is transmitted equally and undiminished in all directions at right angles to all surfaces