Understanding Hydraulics: Basics, Techniques, and Applications

Hydraulics technology has applications in dozens of different industries, including transportation, construction, manufacturing, oil and gas, and nearly every other sector where the lifting and movement of heavy equipment is required.

The equipment that makes use of hydraulics as their source of mechanical advantage can often be highly complex, boasting intricate internal systems and innovative feats of engineering. However, the physical principles underlying the technology are actually quite simple and easy to understand.

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In the following article, we’ll discuss the fundamentals of how hydraulics systems operate, as well as common techniques for their use. We’ll also discuss some of their most widely utilized applications.

Power Under Pressure

All hydraulic systems employ some type of fluid to generate force. Historically, water has been used, although recently, oil has been utilized far more commonly due to its higher levels of viscosity. Technically, however, any fluid will work as long as it is resistant to compression.

The law of physics that underpins hydraulic systems is known as Pascal’s Principle, which, according to NASA, states that “when there is an increase in pressure at any point in a contained fluid, there is an equal increase in every other point in the container.”

This has several implications that can be taken advantage of when designing hydraulic technology. Since the pressure increases equally everywhere, any force that is applied is multiplied by the area of the container that the hydraulic fluid is contained within. This can be expressed by the mathematical formula F = P/A, where F stands for force, P stands for pressure, and A stands for area. It is this ratio of pressure to area that determines the force that can be applied in a given situation.

Designing Hydraulics Technology

Armed with the advantages provided by Pascal’s Principle, engineers tasked with developing new hydraulics systems must determine methods of maximizing the mechanical output for their specific requirements.

At its most basic, a hydraulic system requires two cylinders: a small and a large one. The small one may be attached to a lever, as in a basic gear pump. When the lever is cranked, the force applied to it is multiplied by the area of the larger cylinder, allowing the user to generate vastly more power than they otherwise would.

Depending on the application, a system utilizing hydraulics can be simple or extremely complex. More complicated systems utilize multiple pumps and valves, as well as multiple actuators that can transfer motion in various directions as needed. One example of a more complex system utilizing this method is a forklift. With this and similar machines, the hydraulics are controlled by a pump that is operated by the driver. The pump is used to apply hydraulic force to pistons, which causes a gear to begin to rotate. This gear, in turn, moves a pulley that raises the forks of the machine upward.

Other Considerations

There are several engineering challenges inherent in the creation of forklift technology. First is the need for the system to operate as efficiently as possible. When generating mechanical power, there is always a tradeoff, often in terms of the amount of movement necessary to generate large amounts of power. What this means is that generating enough force to move larger cylinders requires quite a bit of motion from the smaller ones. This is the reason you don’t see hydraulic systems of unlimited size. If they are too large, creating the necessary force is no longer efficient.

The strength of the container is another key factor that engineers must consider. If too much pressure is generated, it’s possible that the equipment will weaken and develop cracks, ultimately causing it to fail to operate.

The velocity of the fluid is also critical. Ideally, the pressurized liquid will move at about 2 to 10 meters per second to achieve the ideal amount of force. Less than this, and the machinery will operate too slowly to be useful. More, however, and the added force can damage the equipment.

Finally, the design of the motion-control systems is also critical to the efficiency and accuracy of hydraulic technology. It’s crucial that the actuators used to transfer motion and move pumps are designed flawlessly. In fact, this element is so critical that whole industries have sprung up around it, with companies such as Aberdeen Dynamics elevating the creation of motion control systems into an art form.

Most Common Applications

Every day, you most likely pass by dozens of different devices that utilize hydraulic technology in some way. Every industry, from small automotive repair shops to nationwide construction companies, has found applications for hydraulic equipment. Its ability to generate vast amounts of power combined with its comparatively low costs means it can be used for operations both large and small.

The construction industry uses hydraulic technology in nearly all its operations. Because most construction equipment requires the ability to generate massive amounts of power in order to move incredible loads over large distances, hydraulics are indispensable in this field.

While we’re on the subject of the large-scale applications of hydraulics, the oil and gas industries also make extensive use of the technology. Oil rigs, which are designed to move tens of thousands of barrels of crude oil per day, use hydraulics in their operations, including drilling.

Hydraulics are also commonly used on smaller-scale operations too. For example, if you took a ride in an elevator today, it likely had a hydraulic pump generating the necessary force to help you avoid the stairs.

Whatever industry you’re in; you can get a much-needed boost to your efficiency by adding hydraulic technology to your arsenal. In doing so, you’ll likely be able to improve your output and, in turn, your bottom line.

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