Hydraulic Principles & Math 190301a

Question 1

If force is given to you in Kilos what must you do to get the force in Newtons?

Answer 1

Multiply Kilos by 9.8

Question 2

If force is given to you in Newtons what must you do to get it in Kilos?

Answer 2

Divide Newtons by 9.8

Question 3

What is 1/4 of pi?

Answer 3

.7854

Question 4

How do you find area ?

Answer 4

Diameter x diameter x .7854

Question 5

To calculate pressure you must ?

Answer 5

Divide force by area

P= F/A

Question 6

Force equals ?

Answer 6

Pressure times area

F=PxA

Question 7

What are the two states of energy?

Answer 7

Kinetic and potential

Question 8

Define work.

Answer 8

Work is force acting through a distance.

Question 9

What are some advantages of hydraulic control?

Answer 9

• relatively compact
• much more flexible then mechanical systems
• cooling and lubrication components are easy to accommodate
• several functions can be controlled at a single time which increases productivity
• hydraulic control is precise, accurate, and smooth
• easily protected from overload and engine stall without machine breakdown

Question 10

What are some disadvantages with hydraulic control.

Answer 10

• if not handled properly could result in serious injury or death
• there is always noise
• leakage can cause contamination and fire
• temp (high or low) can affect reliability and performance
• air in the system can cause erratic or spongy operation and damage
• if not manufactured & maintained correctly they will operate inefficiently

Question 11

Define energy

Answer 11

The ability to perform work.

Question 12

Examples of wasted energy are

Answer 12

Noise and heat

Question 13

Potential energy is ?

Answer 13

Energy that is stored in a body or substance.

Question 14

Kinetic energy is responsible for ?

Answer 14

Movement and motion.

Question 15

What are the two forms of power losses?

Answer 15

1. Pressure losses

2. Flow losses

Question 16

Four advantages of hydraulic control are:

Answer 16

• compact, powerful yet light and take up a small space
• cooling and lubrication systems are easy to accommodate
• control is precise, accurate and smooth
• easily protected against overload without breakdown or stalling

Question 17

List four disadvantages of hydraulic control:

Answer 17

• there is always some noise produced
• leaks are a source of contamination and fire
• temperature variations (high or low) affect reliability and performance
• unless manufactured and maintained correctly they will operate inefficiently

Question 18

The law of conservation of energy states that

Answer 18

Energy cannot be created or destroyed.

Question 19

Kinetic energy in a hydraulic system is created by:

Answer 19

The flow of oil through the system.

Question 20

Define force:

Answer 20

The push or pull that is capable of producing or changing the motion of a body.

Question 21

List the common form of energy:

Answer 21

• mechanical
• hydraulic
• heat
• electrical
• chemical
• light
• sound

Question 22

A hydraulic actuator converts:

Answer 22

Hydraulic energy into mechanical energy.

Question 23

Kinetic energy in a hydraulic system is created by________________

Answer 23

The flow of oil through the system.

Question 24

Potential energy in a hydraulic system is responsible for creating?

Answer 24

Force.

Question 25

Laminar flow refers to:

Answer 25

Flow that moves in straight parallel flow paths.

Question 26

What are three conditions that could result in turbulent flow?

Answer 26

1. Installing conductors that are too small.
2. Abrupt changes in conductor cross-section
3. Abrupt changes in flow direction.

Question 27

Excessive turbulent flow in a hydraulic system will result in excessive:

Answer 27

Pressure losses.

Question 28

Hydraulic actuators that are connected in series will have the same pressure applied to each actuator.

   True or False?

Answer 28

False.

Pressure applied to each actuator will vary while flow remains constant.

Question 29

Actuators connected in series provide ?

Answer 29

Limited torque but high speed.

Question 30

Hydraulic fluids that have a high Vi number:

Answer 30

Have wide viscosity changes with temperature.

Question 31

The oil characteristics that has the most significant effect on the oil’s lubricating ability is:

Answer 31

Viscosity.

Question 32

Two conditions that indicate that an oil is excessively oxidized are:

Answer 32

1. The oil will have a burnt smell.

2. The oil will have a watery feel.

Question 33

What are four entry points of ingressed contamination ?

Answer 33

1. Reservoir air breathers.
2. Pump inlet leakage.
3. Cylinder seals.
4. Unclean maintenance procedures.

Question 34

A rapid total disabling of a system or component is known as an:

Answer 34

Catastrophic failure.

Question 35

Degradation failures are caused by_________________

Answer 35

Gradual surface wear.

Question 36

Viscosity:

Answer 36

Refers to the oil’s resistance to flow.

Question 37

If there is high pressure what will the flow be ?

Answer 37

Low flow.

High pressure: low flow

Question 38

If there is low pressure what will the flow be?

Answer 38

High flow.

Low pressure : high flow

Question 39

Bernoulli’s principle states ?

Answer 39

That as the velocity (flow) of a fluid decreases, the pressure exerted by that fluid increases.

Question 40

Ingressed contamination comes from ?

Answer 40

External sources.