Vane pumps have been around since 1874, when they were invented by Charles C. Barnes of the USA. Though, for any-one not keenly interested in mechanics, they are one of those inventions that form an integral part of our daily lives, but that commonly go unnoticed.
And they do play an integral part in our daily lives.
Vane pumps are usually used as high-pressure hydraulic pumps for cars which allow for braking, supercharging, air-con and auto-transmission. Though there are also mid-range pressure pumps used for things like soft drink dispensers and espresso coffee machines.
That said, these pumps have also become an essential part of air travel, and without them, today’s modern airplanes simply wouldn’t operate.
So to that end, today you’ll learn a little more about vane pumps; a hommage to the mechanical genius that allows us to fly from country to country, and recognition for a piece of engineering that has had a huge impact on our lives, whether or not we know it.
How Vane Pumps Improve Air Travel
What is a Vane Pump?
Vane pumps are a rotary pump designed to handle low and moderate viscosity liquids. It’s a type of vacuum pump that sends a constant flow of liquid through its housing at fixed speed, despite changes in the counter pressure (this is known as positive displacement).
Known as a ‘constant flow machine’, it gives good results when used to handle gasoline, fuel oils, alcohol ammonia, and LP gases, and is most commonly used in the auto industry.
These pumps are are self-compensating for tear and wear, and many different functions rely on it; it has become a critical piece of equipment for braking, power steering, automatic transmission and supercharging.
While most commonly used in cars, many other vehicles also rely on this pump, including airplanes. There are many different configurations of vane pumps, and they are easy to maintain and have good suction.
How Vane Pumps Work
A crucial thing to note when understanding how a vane pump works is that it produces liquid movement of flow – it does not generate pressure. A mechanical action creates a vacuum, which forces liquid from the reservoir to the pump, and moves it into the hydraulic system.
As mentioned above, this is done through positive displacement, and while there are many different configurations of vane pumps, the general principle of how they work remains the same.
Each pump comes fitted with a circular rotor which rotates inside a large circular cavity (called a cam). The centers of these two circles are offset, causing eccentricity (meaning they do not share the same center).
Vanes are allowed to slide into and out of the rotor and seal on all edges, creating vane chambers that do the pumping work. On the intake side of the pump, the vane chambers are increasing in volume. These increasing-volume vane chambers are filled with fluid forced in by the inlet pressure.
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Inlet pressure is actually the pressure from the system being pumped, often just the atmosphere. On the discharge side of the pump, the vane chambers are decreasing in volume, forcing fluid out of the pump. The action of the vane drives out the same volume of fluid with each rotation.
Unlike other pumps, vane pump allows the fluid to travel through the system quickly. This helps to increase the pressure of the fluid. If the fluid is thin, travels faster and increases the pressure considerably.
Image credit: Rainer Bielefeld [CC BY-SA 3.0] via Wikimedia Commons
Application of Vane Pumps in Planes
Virtually all modern aircraft make use of hydraulically powered components. Being that they are engine-driven, air-driven, and utilize electrical driven pumps, it would be absolutely impractical to be able to operate without them.
In smaller, lighter planes, vane pumps might just be used for activating the wheel brakes, though in larger aircraft like Airbus A380 – 800, the use of these systems is much more critical (not that braking isn’t critical in itself!!)
Often depending on the size of the aircraft, multiple hydraulic systems will be working together, and are essential for things like braking, nose wheel steering, extending the landing gears, flaps and slats, operating the cargo doors / loading ramps, and pitch control for the propeller.
They are also used for controlling the windshield wipers; you may not think these require a lot of power or pressure, but when we’re talking about a plane, often traveling at speeds 930 kph, through severe weather lashing down from close proximity in the sky, you need a lot of force.
The advantages of using vane pumps for aerospace to achieve all of this is that it handles thin liquids at relatively high pressure, and compensates for wear through vane extension.
So there you go – the importance of vane pumps for planes – a piece of mechanical engineering that, while you may not have previously heard of, keeps you safe in the sky and delivers you in one piece from destination to destination.
We hope you’ve learned something new and interesting today!