The valves help to direct the flow of the liquid and relieve pressure when needed. In addition to vehicles and industrial machinery, hydraulic systems can be found on ships. Hydraulic systems on ships are used in various applications. For example, systems used for cargo systems make carrying heavy materials and performing other cargo operations easier and less time consuming. These help to regulate valve positions as well as the pneumatic air pressure in the engine room. Plus many industrial ships include machinery and tools like deck cranes that are run by hydraulic systems.
Hydraulic systems can be found on many US Navy vessels. Electric motors, on the other hand, can overheat and burn out if overloaded. Moreover, torque, force, and speed control with pneumatics often requires simple pressure- or flow-control valves, as opposed to more expensive and complex electrical drive controls.
And as with hydraulics, pneumatic actuators can instantly reverse direction, whereas electromechanical components often rotate with high momentum, which can delay changes in direction. Another advantage of pneumatics is that it allows using vacuum for picking up and moving objects. Vacuum can be thought of as negative pressure — by removing air evacuating from the volume between two parts, atmospheric pressure outside the volume pushes the parts together.
For example, attempting to pick up a single sheet of paper or a raw egg presents a challenge with conventional grippers. But with a vacuum pneumatic system, evacuating a suction cup in contact with a sheet of paper or eggshell will cause atmospheric pressure to push the paper or egg against the cup, allowing it to be lifted.
Factory automation is the largest sector for pneumatics technology, which is widely used for manipulating products in manufacturing, processing, and packaging operations.
Pneumatics is also widely used in medical and food processing equipment. Pneumatics is typically thought of as pick-and-place technology, where pneumatic components work in concert to perform the same repetitive operation thousands of times per day. But pneumatics is much more. Because compressed air can have a cushioning effect, it is often called on to provide a gentler touch than what hydraulics or electromechanical drives can usually provide. In many applications, pneumatics is used more for its ability to provide controlled pressing or squeezing as it is for fast and repetitive motion.
Moreover, electronic controls can give pneumatic systems positioning accuracy comparable to that of hydraulic and electromechanical technologies. Pneumatics is also widely used in chemical plants and refineries to actuate large valves. And of course, vacuum is used for lifting and moving work pieces and products. In fact, combining multiple vacuum cups into a single assembly allows lifting large and heavy objects. Standard electric motors typically rotate at 1, or 3, revolutions per minute rpm — much faster than is practical for most machines.
Gasoline and diesel engines also rotate at thousands of rpm when powering equipment. Therefore, some form of power transmission is needed to convert power from the motor or engine to a more useable form — slower speed and, often, linear motion instead of rotary.
Mechanical power transmission components also include ball screws, rack-and-pinion assemblies, chain drives, and other components that convert rotational motion and torque to linear motion and force. Electrical methods of power transmission regulate electrical power to the motor to control speed and torque. But these methods cannot convert the rotary motion of a motor to linear. Once they understand how the system operates and put it together, they use it to try to move specific pieces of material.
Engineers use fluid power to impact such areas as lowering fuel consumption in the transportation industries to improving patient care in the medical industries. Fluid power can improve our quality of life when engineers and researchers investigate how to use this technology to become more efficient, compact and cost effective.
Each TeachEngineering lesson or activity is correlated to one or more K science, technology, engineering or math STEM educational standards. In the ASN, standards are hierarchically structured: first by source; e. View aligned curriculum. Do you agree with this alignment? Thanks for your feedback! Students are introduced to Pascal's law, Archimedes' principle and Bernoulli's principle.
Fundamental definitions, equations, practice problems and engineering applications are supplied. Working in teams, students learn the basics of fluid power design using the PFPD as their investigative platform. With the main components of the PFPD already assembled, student groups determine the correct way to connect the valves to the actuators using colored, plastic tubing.
The purpose of this lesson is to teach students how a spacecraft gets from the surface of the Earth to Mars. Students first investigate rockets and how they are able to get us into space. Finally, the nature of an orbit is discussed as well as how orbits enable us to get from planet to planet — spec Figure 2. The use of fluid power, such as the hydraulics in this bulldozer, helps people do jobs more quickly, safely and economically. All rights reserved. Have ready two balloons, a bottle, water and two matchsticks for simple teacher demonstrations.
Also be ready to show the class one or two minute online videos. Have you ever seen a bulldozer or excavator move a lot of dirt where a new project is being built see Figure 2? Have you been in a chair that you could raise or lower by pushing a lever? Did you ever open a screen door and notice it closes smoothly and by itself?
Did a dentist ever use a drill on your teeth? When you are riding in a car or truck and the driver pushes the brake pedal, do you start to slow down? These are all examples of how fluid power is used in our everyday lives.
Fluid power use either a gas pneumatics or a liquid hydraulics. Do you know what the previous examples used? Most people do not even realize that fluid power is helping people to perform jobs more quickly, efficiently, accurately and powerfully than ever before.
Can you imagine if we didn't have fluid power and someone had to move a bunch of dirt without bulldozers that use hydraulics? How long would it take to move it another way? How much energy would be needed? Years ago, a chair that today uses pneumatics to move up and down easily with the push of a lever was raised or lowered by spinning it around over and over — very time consuming! Before dentists had the precision and control of pneumatic drills, they worked with much less precise and controlled drills, which were less comfortable for patients.
Going to the dentist today is really not so bad compared to what people went through years ago. What about the brakes in your car or truck? How did people stop their vehicles before we had hydraulic braking systems? How effective were those systems? How safe were those older systems? These examples are just a few of the many ways fluid power improves our everyday lives. What do you think makes up a fluid power system?
Think of some of the examples we just talked about. What can you recall about how these devices and machines look? How do the pieces move in relation to one another?
Have students demonstrate to the class what fluid power devices look like and how they operate using the classroom board or in another form. How do you think a front-end loader can lift so much dirt note the bucket size in Figure 3 so easily? How much power is needed to lift something that large? The power is generated through the use of fluid power. Figure 3. Heavy machinery such as this front-end loader use hydraulic power to move heavy material.
Fluid power is ideal for high speed, high force and high power applications such as this. Before going on further, let's learn about where the concept of fluid power began.
Many years ago, in the s, a French scientist and mathematician named Blaise Pascal pas KALZ or PAS kulz stated a physical law that describes the effect of applying pressure on a fluid whether gas or liquid in a closed container. Pascal's law states that pressure applied to an enclosed fluid is transmitted with equal force throughout the container. So what does that really mean to you? Do you think you have ever seen Pascal's law in action?
How many of you have ever tried to step onto a balloon? I need a volunteer inflate a balloon to demonstrate the following. This volunteer will step on the balloon while we observe the effects of their actions. What do you think will happen when they step on the balloon? Why do you think it would do that? Have the student volunteer step on the balloon and make sure students make observations. Did the balloon do what you thought it would? Why did it do that?
Fluid power systems are used in a variety of applications from braking systems on cars to robotics to heavy machinery. These systems produce linear motion using either hydraulic or pneumatic cylinders. Compare fluid power with two other methods of power transmission, electrical and mechanical, which usually need a mechanical device to convert rotational motion to linear motion.
Typically, fluid power systems use valves to control direction, speed, force and torque. Hydraulics is all about physics.
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