PNA1

Question 1

Cavitation can be the result of

Hydraulic fluid with low viscosity
Running pump at too high speeds
Increasing inlet flow
Removing inlet stainer

Answer 1

Running pump at too high of speed

Question 2

An example of a dynamic pump would be

Impeller
Vane
Gear
Piston

Answer 2

Impeller

Question 3

A spring that extends by force and retracts by spring or Gravity is known as

Answer 3

Single acting

Question 4

The flow produced by a pressure compensated pump during cylinder extension is at

Load pressure
Relief pressure
Stand by plus load pressure
Stand by pressure

Answer 4

Load pressure

Question 5

The flow produced by a pressure compensated pump at the end of its stroke is at

Stand by pressure
Load pressure
Relief pressure
No flow produced

Answer 5

Relief pressure

Question 6

The purpose of a cycling cushion is to

Answer 6

Reduce amount of shock

Question 7

The pump in a hydraulic system produces

Answer 7

Fluid flow

Question 8

An unbalanced vane pump can be identified by its

Answer 8

Off Center cam ring

Question 9

Variable displacement vane pumps control fluid flow by

Answer 9

Shifting the cam ring

Question 10

The vanes of the vane pump maintain contact with the cam ring by

Answer 10

Sets of inlet outlet ports opposing each other

Question 11

A pumps input is 15gpm and measured output is 12gpm at 1000 psi. The volumetric efficiency is?

Answer 11

80%

12 div by 15 x 100

Question 12

The displacement of a bent axis piston can be varied by

Answer 12

Pivoting the cylinder block to change the angle of the shaft

Question 13

The toque of a hydraulic motor is dependent upon

Answer 13

Inlet pressure, surface area, and radius of rotation

Question 14

If a cylinder had internal leakage it would effect

Answer 14

Pressure

Question 15

Hydraulic motors are driven by

Answer 15

Fluid flow and pressure

Question 16

Balance vane motors maintain vane contact by

Answer 16

Fluid pressure/springs

Question 17

In an inline axial piston motor, speed can be increased by

Answer 17

Decreasing swash plate angle

Question 18

The purpose of the stop tube is to

Answer 18

Reduce side load when extended

Question 19

In a rotary piston pump, the fluid is ported in and out of the cylinder through the

Answer 19

Pintle

Question 20

The output flow of gear pumps can be adjusted by

Answer 20

Changing rpm or a prime mover

Question 21

A radial piston motor can be classed as

Answer 21

Low speed/high torque

Question 22

O-ring boss port connections have what type of threads

Answer 22

Unified national fine

Question 23

Three main styles of pumps

Answer 23

Piston
Vane
Gear

Question 24

What is require at the pumps In order for oil to flow into the inlet

Answer 24

Negative pressure

Question 25

What cylinder style is the most common in hydraulics

Answer 25

Double acting cylinder

Question 26

What type of cylinder has two Pistons attached to a rod to obtain extra force

Answer 26

Tandem Used for high force, short stroke

Question 27

What part of a cylinder contains the load pressure

Answer 27

Barrel

Question 28

When the main port connections are at the bottom how do you remove entrapped pressure

Answer 28

Bleed port

Question 29

a symptom of a hot spot would indicate what in a cylinder

Answer 29

Internal leaks

Question 30

Jerky movement, squealing or rattling sound is a sign of what in a cylinder

Answer 30

Aeration Or Misalignment

Question 31

Hydraulic motors convert what type of power into rotary motion and produce toque to drive

Answer 31

Fluid power

Question 32

Smooth operation and heavy loads and low speeds of 2rpm describe what type of hydraulic motor

Answer 32

LSHT low speed high torque

Question 33

Crane hoist, dynamic rollers slow turning vaccume screens all require what type of hydraulic motor

Answer 33

LSHT

Question 34

Three types of LSHT motors

Answer 34

Radial piston Cam type roller vane

Question 35

Fans generators and compressor all require what type of hydraulic motor

Answer 35

HSLT

Question 36

What motor cymbal has a half circle with two arrows pointing up

Answer 36

Limited rotation motor

Question 37

Torque depends on what three 3 key elements

Answer 37

Inlet pressure, surface area, radius of rotation

Question 38

Motor speed depends on what two factors

Answer 38

Flow rate | Volume

Question 39

What is the advantage of the roller vane Gerotor design

Answer 39

It reduces the friction between gears by using rollers in place of internal gear teeth.

Question 40

What do the orbiting gear rotor and roller vane Gerotor have in common

Answer 40

Orbiting star shaped gear

Question 41

All 4 piston motors operate under the same principle which is...

Answer 41

Pressurized inlet fluid pushes on the piston to produce rotation through either swash plate or a cam

Question 42

What valve is spring loaded and opens when the filter clogs is hydraulic motors

Answer 42

Spring load check valve

Question 43

A pressure drop of over 45psi is hard on filter elements and wastes power. A pressure drop of 85 psi at 20gpm consumes about how much HP

Answer 43

1HP

Question 44

Bypass Indicator colour Green = Yellow = Red =

Answer 44

Green - Full flow is passing through filter Yellow - bypass valve is beginning to open (yellow is a good indication for filter change) red - Filter is clogged

Question 45

What filter has 20% of the total system preset pass through it every minute

Answer 45

Return line filter

Question 46

What filters are used imidatly after the pump

Answer 46

Pressure line filters