Week – 15, Fluid Power – Part 1

The term fluid power covers a very broad description of a technology principal, that uses a confided fluid to convert energy from a mechanical input power source to a fluid power output source.  This  following blog  provides an introduction to the amazing world of Fluid Power, with a how a simple concept of using Energy, Flow, Pressure and Fluid changed the world.

An important note; we all know there is a plethora of Fluid Power articles scatted across the internet and beyond, describing many different views of fluid power applications and technologies. This is not about re-inventing the wheel, but more about setting the scene for what will evolve into a series of interesting articles about Fluid Power Circuits operating in whole of range of different applications.   Let’s start with the foundation recap:

Dozer Drawing_W200What is Fluid Power?

ForefathersUtilization of fluid for various purposes, such as transferring energy, lifting objects or any such kind of work goes back to 200 BC. The first person as known to the world, who utilized fluid power is Archimedes. The other, to name a few is Pascal, Bernoulli, and Euler who worked in the field of fluid power in the past. These forefathers left the Fluid Power Industry with many mathematical principals that remain important essentials for understanding the science of fluid power applications.

Definitions: No doubt there are many ways of defining fluid but in simple words; it is defined as a mass/matter that flows continuously. A few examples of fluid are water (called as universal fluid), oil, milk, etc: – any of such kind. Besides, air is also a fluid. Is it not different from water or oil? Yes it is true. Fluids are further classified as liquids & gases. This classification is made on their difference in unique properties, as we get more in-depth with upcoming articles, the technicalities of fluids will be explored in detail in how it effects Fluid Power Systems.

Fluid power: It is the use of fluid under certain conditions to generate, transmit & control power. Suppose we use liquid for this purpose, then we call it hydraulics/ hydraulic power. In case we use gas, for the purpose, it is called pneumatics/pneumatic power.

Benefits of Fluid Power : There are many examples and descriptions explaining how Fluid power systems can be beneficial to a machine or application design; the NFPA (National Fluid Power Association website – www.nfpa.com)  provides a simple 7 key descriptions of the most common benefits a Fluid Power System can provide:

  1. Multiplication and variation of force-Linear or rotary force can be multiplied from a fraction of an ounce to several hundred tons of output.
  2. Easy, accurate control-You can start, stop, accelerate, decelerate, reverse or position large forces with great accuracy. Analog (infinitely variable) and digital (on/off) control are possible. Instantly reversible motion-within less than half a revolution-can be achieved.
  3. Multi-function control-A single hydraulic pump or air compressor can provide power and control for numerous machines or machine functions when combined with fluid power manifolds and valves.
  4. High horsepower, low weight ratio-Pneumatic components are compact and lightweight. You can hold a five horsepower hydraulic motor in the palm of your hand.
  5. Low speed torque-Unlike electric motors, air or hydraulic motors can produce large amounts of torque (twisting force) while operating at low speeds. Some hydraulic and air motors can even maintain torque at zero speed without overheating.
  6. Constant force or torque-This is a unique fluid power attribute.
  7.  Safety in hazardous environments-Fluid power can be used in mines, chemical plants, near explosives and in paint applications because it is inherently spark-free and can tolerate high temperatures.

It’s is these  attributes that we will explore in further detail in coming articles.


Next Article Describes what makes up a Fluid Power System?