Fluid Power
Fluid PowerLinks to Press Releases:
Fluid Power Challenge – Article in TSM news letter 2017.
Fluid Power Challenge- Press Release 2016 Alexandria, MN
2017 Participants
NFPA Fluid Power Challenge
The NFPA Fluid Power Challenge is a competition that challenges eighth grade students to solve an engineering problem using fluid power. They work in teams to design and build a fluid power mechanism, and then compete against other teams in a timed competition. The NFPA Fluid Power Challenge: NFPA Fluid Power Challenge logo
red arrow bullet Challenge
Highlights
•Actively engages students in learning about fluid power.
•Gives support and resources to teachers for science and technology curriculum.
•Creates a learning environment where math and science are fun.
•Encourages students to acquire a diversity of teamwork, engineering and problem-solving skills.
•Introduces eighth graders to careers in the fluid power industry.
•Helps build a strong workforce for tomorrow.
Fluid power systems consist of four basic components: reservoir/receiver (fluid storage); pump/compressor (converts mechanical power to fluid power); valve (controls direction and amount of flow); and actuators (converts fluid power to mechanical power, that is, cylinder and pistons). The connectors for these components consist of pipe, tube or hoses so the fluid can flow to/from the components.
Pascal’s law : if a confined fluid is at rest, pressure is transmitted undiminished in all directions and exerts equal force on all areas, in addition to right angles to them.
p = F / A
p = pressure (lbs/in2 or N/m2); F = force (lbs or N); A= πr2 = area (in2 or m2)
Boyle’s law: The volume of gas at constant temperature varies inversely with the pressure exerted on it.
p1(V1) = p2(V2)
V = volume (in3 or m3); p = pressure (lbs or N)
Charles’ law: The volume of gas increases or decreases as the temperature increases or decreases, provided the amount of gas and pressure remain constant.
V1/ T1) = V2/ T2
V = volume (in3 or m3); T = absolute temperature (°R)
Gay-Lussac’s law: The absolute pressure of a gas increases or decreases as the temperature increases or decreases, provided the amount of gas and the volume remain constant.
p1/ T1) = p2/ T2
p = absolute pressure (lbs/in2 or N/m2); T = absolute temperature (°R)
Flow is what operates the actuators in the cylinders. Flow rates, which determine actuator speed, are measured in in3 per sec or gallons per minute, and are generated by a pump. When flow is given, the actuator volume displacement directly affects actuator speed. The less volume to displace in the cylinder leads to faster actuators. In general, pressure is the resistance to flow. Pumps produce flow, not pressure!
Q = VA
Q = volumetric flow rate (in3/sec); V = velocity (in/sec); A = area (in2)
Torque is a twisting force that is found by multiplying the force times the distance. It is measured in foot pounds. Hydraulic and pneumatic pumps produce work to be used within the fluid power system. Given a specific motor torque and motor RPM, specifies energy usage or horsepower requirement.
Fluid power is all about moving energy from one location to another. Energy is the ability to do work. Energy transfer is the energy moving from the prime mover, or input source, to an actuator, an output device. Work is defined as force multiplied by distance. This is measured in foot-pounds. Power is the rate of doing work. It is found by dividing work over time (in seconds). Horsepower, a unit measurement of energy, is a common term used to measure power. Horsepower can be calculated by the following:
flow (gallons per minute) X pressure (lbs/in2)
1714 (which is always constant)
The law of conservation of energy states that energy can neither be destroyed nor created but may change forms. Any energy that is not transferred to work takes the form of heat energy.
Vocabulary/Definitions
| absolute pressure: | The total pressure exerted on a system, including atmospheric pressure. |
| atmospheric pressure: | The pressure exerted by the weight of the atmosphere above the point of measurement. |
| Boyle’s law: | The volume of a gas at constant temperature varies inversely with the pressure exerted on it. |
| Charles’ law: | The volume of a confined gas is proportional to its temperature, provided its pressure remains constant. |
| check valve: | A valve that allows flow in one direction but prevents flow in the opposite direction. |
| compressor: | An air pump that compresses air into a receiver tank. |
| crank: | A part of an axle or shaft bent out at right angles, for converting reciprocal to circular motion and vice versa. |
| cylinder: | A device used to convert fluid power into mechanical power in the form of linear motion. |
| directional-cntrol valve: | Used to control which path fluid takes in a circuit. |
| double-acting cylinder: | A cylinder that can act under pressure in both directions (extend and retract) to move a load. |
| filter: | A device used to remove contamination from a fluid. |
| flow meter: | A device used to measure flow rate. |
| flow rate: | The volume of fluid that moves through a system in a given period of time. |
| flow velocity: | The distance the fluid travels through a system in a given period of time. |
| flow-control valve: | Used to start and stop flow in a circuit. |
| fluid power: | The use of a fluid (liquid or gas) to transmit power from one location to another. |
| Gay-Lussac’s law: | The absolute pressure of a confined gas is proportional to its temperature, provided its volume stays constant. |
| hydraulics: | The use of a liquid flowing under pressure to transmit power from one location to another. |
| lubricator: | A device used to spray an oil mist into the stream of a pneumatic system. |
| Pascal’s law: | Pressure exerted by a confined fluid acts undiminished equally in all directions. |
| piston: | A sliding piece moved by or moving against fluid pressure, which usually consists of a short cylindrical body fitting within a cylindrical chamber or vessel along which it moves back and forth. |
| pneumatics: | The use of gas flowing under pressure to transmit power from one location to another. |
| pressure: | The force per unit area exerted by a fluid against a surface. |
| pressure regulator: | A type of pneumatic pressure control valve that controls the maximum pressure in a branch of a circuit. |
| pressure relief valve: | A type of pressure control valve that limits the maximum pressure in a hydraulic or pneumatic circuit. |
| pump: | A device used to create flow in a hydraulic system. |
| receiver tank: | A device that holds the compressed air in a pneumatic system. |
| reservoir: | The tank that holds the fluid in a hydraulic system. |
| single-acting cylinder: | A cylinder that acts under pressure in one direction only and returns automatically when the pressure is released. |
| solenoid: | A switching device that uses the magnetic field generated by an electrical current for actuation. |
| transmission Lines: | Used to transport fluid in a circuit. |
| valve: | Any device that controls, either automatically or manually, the flow of a fluid. |
| viscosity: | A measure of a fluid’s thickness or resistance to flow. |
| volume: | The amount or quantity of something.The amount or quantity of something |
Updated 4/6/2017