Pumps & Actuators

Question 1

Cavitation can be a result of?

Answer 1

Running a pump at a high speed

Question 2

An example of a dynamic pump would be

Impeller
Vane
Gear
Piston

Answer 2

Impeller

Question 3

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

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

Answer 3

Load pressure

Question 4

The purpose of a cylinder cushion is to

Provide a reserve of oil
Eliminate pressure fluctuation
Reduce mechanical shock
Limit amount of travel

Answer 4

Reduce mechanical shock

Question 5

The pump in a hydraulic system produces

Fluid pressure
Fluid flow
Fluid resistance
Fluid force

Answer 5

Fluid flow

Question 6

An unbalanced came pump can be identified by its

Off-centre cam ring
Counter weights
Dual inlet ports
Spring under vanes

Answer 6

Off-centre cam ring

Question 7

Variable displacement cane pumps control fluid flow by

Changing discharge port
Shifting the cam ring
Shifting the housing
Changing the inlet port

Answer 7

Shift the cam ring

Question 8

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

Answer 8

Centrifugal force and fluid pressure

Question 9

A balanced vane pump would have

• Eccentric cam drive
• Large bearings to carry side load on shaft
• sets of inlet outlet ports opposing each other

Answer 9

Inlet ports opposing each other

Question 10

The displacement of a bent axis piston pump can be varied by

• Changing swash plate angle
• Pivoting cylinder block to change angle to shaft
• changing the length of the universal link
• shifting the cam ring

Answer 10

Pivoting cylinder block to change angle of shaft

Question 11

The torque of a hydraulic motor is dependent upon

• Inlet pressure, surface area, and radius of rotation
• volumetric and mechanical efficiency
• flow rate and load pressure
• RPMs and inlet pressure

Answer 11

Inlet pressure, surface area and radius of rotation

Question 12

Torque is the rotational force of a motor. It is expressed in

Foot pounds - imperial
Newton meter - metric
Both

Answer 12

Both

Question 13

How is a hydraulic motor operated

Answer 13

Very similar to a hydraulic pump design.

The fluid pushes on Pistons, vanes, or gear teeth to rotate the drive shaft.

Question 14

Name three symptoms and three problems that can occurs with hydraulics

Answer 14

-Hot sports = internal leaks
-Jerky movement = aeration
Binding = misalignment between rod and load

Question 15

Moto speed depends on what two factors?

Answer 15

Flow rate

Volume

Question 16

Pressure required to operate a motor depends on?

Answer 16

Load and displacement

Question 17

What type of hydraulic motor has has a star shaped gear that orbits as it rotates inside a stationary gear?

Answer 17

Orbiting gear and roller vane Ge-rotor

Question 18

Piston motors

Inline axial, bent axis, radial piston, and cam type radial piston all operate on what same principle?

Answer 18

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

Question 19

Inline axial piston motors and pumps are identical except for what?

Answer 19

Inlet and exhaust ports on the motor are the same size

Question 20

Double acting cylinders are most common in industry - three types you may encounter are?

Answer 20

Basic double acting cylinder, double rod cylinder, and tandem

Question 21

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

Answer 21

Tandem

Higher force shorter stroke