Hydraulic Principles & Math 190301a Flashcards
If force is given to you in Kilos what must you do to get the force in Newtons?
Multiply Kilos by 9.8
If force is given to you in Newtons what must you do to get it in Kilos?
Divide Newtons by 9.8
What is 1/4 of pi?
.7854
How do you find area ?
Diameter x diameter x .7854
To calculate pressure you must ?
Divide force by area
P= F/A
Force equals ?
Pressure times area
F=PxA
What are the two states of energy?
Kinetic and potential
Define work.
Work is force acting through a distance.
What are some advantages of hydraulic control?
- 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
What are some disadvantages with hydraulic control.
- 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
Define energy
The ability to perform work.
Examples of wasted energy are
Noise and heat
Potential energy is ?
Energy that is stored in a body or substance.
Kinetic energy is responsible for ?
Movement and motion.
What are the two forms of power losses?
- Pressure losses
2. Flow losses
Four advantages of hydraulic control are:
- 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
List four disadvantages of hydraulic control:
- 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
The law of conservation of energy states that
Energy cannot be created or destroyed.
Kinetic energy in a hydraulic system is created by:
The flow of oil through the system.
Define force:
The push or pull that is capable of producing or changing the motion of a body.
List the common form of energy:
- mechanical
- hydraulic
- heat
- electrical
- chemical
- light
- sound
A hydraulic actuator converts:
Hydraulic energy into mechanical energy.
Kinetic energy in a hydraulic system is created by________________
The flow of oil through the system.
Potential energy in a hydraulic system is responsible for creating?
Force.
Laminar flow refers to:
Flow that moves in straight parallel flow paths.
What are three conditions that could result in turbulent flow?
- Installing conductors that are too small.
- Abrupt changes in conductor cross-section
- Abrupt changes in flow direction.
Excessive turbulent flow in a hydraulic system will result in excessive:
Pressure losses.
Hydraulic actuators that are connected in series will have the same pressure applied to each actuator.
True or False?
False.
Pressure applied to each actuator will vary while flow remains constant.
Actuators connected in series provide ?
Limited torque but high speed.
Hydraulic fluids that have a high Vi number:
Have wide viscosity changes with temperature.
The oil characteristics that has the most significant effect on the oil’s lubricating ability is:
Viscosity.
Two conditions that indicate that an oil is excessively oxidized are:
- The oil will have a burnt smell.
2. The oil will have a watery feel.
What are four entry points of ingressed contamination ?
- Reservoir air breathers.
- Pump inlet leakage.
- Cylinder seals.
- Unclean maintenance procedures.
A rapid total disabling of a system or component is known as an:
Catastrophic failure.
Degradation failures are caused by_________________
Gradual surface wear.
Viscosity:
Refers to the oil’s resistance to flow.
If there is high pressure what will the flow be ?
Low flow.
High pressure: low flow
If there is low pressure what will the flow be?
High flow.
Low pressure : high flow
Bernoulli’s principle states ?
That as the velocity (flow) of a fluid decreases, the pressure exerted by that fluid increases.
Ingressed contamination comes from ?
External sources.
