Why use hydraulics

Handling hydraulic fluids is messy, and it can be difficult to totally get rid of leaks in a hydraulic system. If hydraulic fluid leaks in hot areas, it may catch fire.

If hydraulic lines burst, they can cause serious injuries. Take care when handling hydraulic fluids, as too much exposure can lead to health issues. Hydraulic fluids are also corrosive, but some types are less so than others. For example, two main types of brake fluid are available for hydraulic mountain bikes, DOT fluid and mineral oil. Due to its non-corrosive properties, mineral oil is less likely to destroy a bike's paintwork.

To keep your hydraulic system in its prime, periodically check hydraulic systems for leaks, lubricate when necessary, and change filters and seals as required. Claire is a writer and editor with 18 years' experience. She writes about science and health for a range of digital publications, including Reader's Digest, HealthCentral, Vice and Zocdoc.

How a Hydraulic Jack Works. Hydraulic Jack Information. Uses of Hydraulic Systems. Hydraulic System Disadvantages. How to Calculate Hydraulic Cylinder Tonnage. Pneumatic Cylinder Definition. Different Hydraulic Systems. Any aircraft is able to maintain this performance with regular servicing of the hydraulic systems. With the exception of physical damage, a cylinder can be serviced and replaced many times, and if done proactively, allows the hydraulic systems to last decades.

Hydraulics may one day harness the superfluid. A superfluid, such as liquid helium, moves with zero viscosity. As you can imagine, a superfluid can be pumped at massive volumes with no backpressure.

Fluid lines could be miniscule, but still pump at a high rate. A superfluid will even travel against gravity under its own volition; nobody said quantum physics made sense. The challenges with a superfluid are numerous, which is why this is a technology for the future.

Liquid helium requires pretty much absolute zero to be a superfluid, which makes it difficult to take advantage of. The entire hydraulic system would have to be self-contained in a space with no thermal energy.

Because liquid helium has zero viscosity, you can imagine how prone to leakage a hydraulic system would be. Not only would a helium pump spin freely as if it was pumping in a vacuum, any actuator would not be able to take advantage of the moving liquid helium. This superfluid would enter a hydraulic cylinder and proceed to move past the piston seals as if there was no piston even in the cylinder.

Challenges aside, superfluidity is a fantastic concept, with too many benefits to ignore in Future World. All engineers should read this.

I fear that most fluid power actuator developers have, in some sense, just given up in the face of computer controlled electric drives. I wonder what the military is actually doing about possible emp attacks on their tanks and planes? Ever since I developed my stepper, these thoughts have crossed my mind, especially the development of ultra-high pressure actuators. I am indebted to them for getting me into the field and for encouraging me to continue graduate education.

I worked on problems related to mobile equipment and aircraft, as well as taught two graduate level courses in Fluid Power. But, there was another opportunity. I have been involved in dynamic systems and controls over the years. Lateral guides at that time were electrohydraulic control systems. We still have one system in use in our lab. I also teach a junior level course in Dynamic Systems Analysis required of all juniors in mechanical and aerospace engineering.

I have a masters student interested in doing research in Fluid Power. They each use a pump as an actuator, are controlled by valves, and use fluids to transmit mechanical energy. The biggest difference between the two types of systems is the medium used and applications. Pneumatics use an easily compressible gas such as air or other sorts of suitable pure gas—while hydraulics uses relatively incompressible liquid media such as hydraulic or mineral oil, ethylene glycol, water, or high temperature fire-resistant fluids.

Neither type of system is more popular than the other because their applications are specialized. This article will help you make a better choice for your application by describing the two types of systems, their applications, advantages, and disadvantages.

The load or the force that you need to apply, the output speed, and energy costs determine the type of system you need for your application. Pneumatics is a branch of engineering that makes use of pressurized gas or air to affect mechanical motion based on the working principles of fluid dynamics and pressure.

The field of pneumatics has changed from small handheld devices to large machines that serve different functions. Pneumatic systems are commonly powered by compressed air or inert gases. The system consists of interconnected set of components including a gas compressor, transition lines, air tanks, hoses, standard cylinders, and gas atmosphere.

The compressed air is supplied by the compressor and transmitted through a series of hoses. The air flow is regulated by manual or automatic solenoid valves and the pneumatic cylinder transfers energy provided by the compressed gas to mechanical energy.

A centrally located and electrically powered compressor powers cylinders, air motors, and other pneumatic devices.

Most industrial pneumatic applications use pressures of about 80 to pounds per square inch to kPa. The compressed air is stored in receiver tanks before it is transmitted for use. The compressors ability to compress the gas is limited by the compression ratios. Pneumatic systems are typically used in construction, robotics, food manufacturing and distribution, conveying of materials , medical applications dentistry , pharmaceutical and biotech, mining, mills, in buildings, and tools in factories.

Pneumatic systems are primarily used for shock absorption applications because gas is compressible and allows the equipment to be less susceptible to shock damage. Pneumatic systems are selected above hydraulic systems because of the lower cost, flexibility, and higher safety levels of the system. Pneumatic systems are best suited for applications which require no risk of contamination because they offer a very clean environment for such industries as biotech, dentistry, pharmaceutical, and food suppliers.

Since they use clean, dry, compressed air, the system can quickly convey items. The straight and simple design prevents clogging and reduces maintenance. Pneumatic systems are easy to install and portable.

They are reliable and has an initial low setup cost because they operate on comparatively low pressure and inexpensive components that reduces operation costs. No container is required to store the air that will be compressed because it is drawn from the surrounding atmosphere and filtered optional. The entire system is designed using standard cylinders and other components.

The air or gas used in a pneumatic system is typically dried and free of moisture so that it does not create issues to internal components.

Pneumatic systems provide rapid movement of cylinders because the air compressor flow rates. Air is very agile and can flow through pipes very easily and quickly with little resistance.

Pneumatic systems are available in a wide variety in very small sizes. The pneumatic systems are clean and do not pollute because any exhaust is released into the atmosphere.

The Pneumatic system is more agile because if the system needs to change directions, the simple design and control allows operators to update the system quickly without environmental impact. Pneumatics are cheaper than hydraulic systems because air is inexpensive, plentiful, easy to obtain, and store.

Pneumatic systems generally have long operating lives and require little maintenance because gas is compressible, and the equipment is less subject to shock damage. Unlike hydraulic systems that use liquids that transfers force, gas absorbs excessive force.

Safety is an important advantage of choosing Pneumatic systems. Since Pneumatic systems run on compressed air, there is very little chance of fire compared with explosion or fire hazard of using compressed hydraulic oil. It is also maintenance free since there is little need to replace filters. It is essential to determine the amount of force required for your application because not as much force is created with pneumatic systems as with hydraulic systems. Pneumatic systems do not offer the same potential force as hydraulic systems so they should not be used for applications that require lifting or moving heavy loads.

Compressed air experiences air pressure fluctuations, so that movement can be jerky or spongy at times while moving or lifting loads. A larger cylinder is needed to produce the same force that a hydraulic ram can produce. In terms of energy costs, pneumatic systems cost more than hydraulics because the amount of energy lost through heat produced while compressing air.