Most people enjoy theme parks as a place to get away from work, but for those in the hydraulics industry, they are a place to demonstrate their expertise. Behind many of the rides that make your stomach drop or your eyes blink in amazement, Parker's accumulators are picking up the stresses and enhancing the performances of hydraulic technology.
Behind the scenes, there is complex machinery that must run precisely and smoothly to ensure safe and reliable operation. Whether you are splashing through water, sailing above the tree lines, or being wowed by animations and simulations, powerful equipment that depends on the science and engineering of hydraulics is enriching your activities. And, many of these large, powerful hydraulic systems rely on accumulators; hidden from the public view, but critical in their roles.
The role of accumulators
Typically, accumulators installed in hydraulic systems store energy to either provide an extra boost of power or absorb energy to smooth out pulsations. One of the world's largest manufacturer of accumulators is Parker's Accumulator and Cooler Division. According to Jeff Sage, product sales manager, the Parker accumulators used in theme parks are gas-charged and are either bladder accumulators or piston accumulators. Parker manufactures both types and has the engineering expertise to recommend which kind best fits the requirements of a particular ride.
Bladder accumulators are cylinders that contain a rubber bladder (Figure 1). Hydraulic oil is kept under pressure when the bladder is inflated with an inert compressed gas, often nitrogen. When a ride needs a quick burst of power, a valve opens and releases the pressurized hydraulic fluid.
Piston accumulators are metal tubes with an enclosed piston(Figure 2). One side of the piston is charged with a pressurized gas and the other side with hydraulic oil. When the ride requires additional power, the pressurized gas pushes against the piston which forces hydraulic oil back into the ride’s power unit.
Watch it in action:
Accumulators often play valuable roles in hydraulic systems that power rides for a variety of reasons. As you can imagine, moving multi-ton cars, coasters, and props, often times with rapid acceleration in minimal time, requires extreme bursts of force. Delivering this concentrated force is taxing on hydraulics systems and can cause jerky movements. Accumulators work to absorb these extreme pressures and movements, store energy and keep performance consistent – delivering the extra “push” when a hydraulics system needs it.
Often there are many accumulators used on each ride. For example, on motion-simulator rides, which have become quite popular since the 1980s, many accumulators are used. These are amazing rides where people feel all the shakes, rattles and rolls depicted in a movie shown on a large screen. A big surge of energy is needed to move the platform. Within these rides there are 24 platforms, each with banks of 10-gallon bladder accumulators. Each time the platform moves, a quick burst of energy is needed. These accumulators provide the high acceleration needed to make the ride exciting and memorable.
Safety, of course, must be at the forefront of manufacturing accumulators. A ride that breaks down can cause injuries or worse. Most bladder accumulator failures come from the bladder failing. Parker accumulators minimize the issue by manufacturing its own bladders for quality control reasons. This is not common and differentiates Parker from the competition.
Knowing how important the chemical process is in the making of these bladders, the company has its own chemist, buys the rubber and mixes the bladder compounds. With everything controlled and created in-house, this helps Parker produce accumulator bladders that are of the highest quality and reliability.
And when a piston accumulator fails it is typically a result of a leak in the rubber seal located on the outer cylinder of the piston. A proper functioning seal separates the gas from the oil. Gas molecules are very small and can penetrate through the rubber seal. Parker applies its expertise in rubber composition to develop seals that minimize the gas permeation, thus extending the life of the piston accumulator.
More on reliability
Nothing stops the fun at a theme park like a sign at a ride’s entrance that says, “OUT OF ORDER.”
Carlos Aguirre, a Sales and Systems engineer at Bernell Hydraulics Inc., uses Parker because of their accumulator expertise, reliability, and service. Bernell and Aguirre have a long history of working with the nation’s top theme parks and using Parker's accumulators to keep the attractions running smoothly and safely. Aguirre and his teams work overnight after theme parks close, so it’s essential that he chooses trusted vendor partners that can deliver dependable parts when they are needed. While most of Aguirre’s theme park projects have used bladder accumulators, new projects are requiring piston accumulators.
“Park patrons want to enjoy their favorite rides. I need quality parts delivered on time so we can get the work done at night and have the ride ready to roll when the gates open in the morning. I like the expertise Parker offers on either type. One call and I get the information I need to make theme parks fun and safe for all.”
Carlos Aguirre, sales and systems engineer at Bernell Hydraulics Inc.
The next time you’re at a theme park waiting to ride, we hope that the greatest energy is the energy of the moment. However, you might take a moment to appreciate the extreme amounts of force and energy required for your favorite ride to give you a hair-raising experience. For our accumulators, handling the exciting extremes is a walk in the park.
If you would like more information about accumulators, visit Parker Accumulator and Cooler Division.
Article contributed by Jeff Sage, product sales manager, Parker Hannifin Accumulator and Cooler Division.
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