# Fluid Power: A Basic Introduction to Hydraulics and Its Uses

Blog | June 16th, 2015

Any tool or component that relies on hydraulic engineering is gifted with a talent for magnifying input energy, a fact that’s been established by several basic laws of physics. The underlying principles that define fluid dynamics agrees with this summation and Pascal’s Law positively defines the law in motion, showing that an increase in pressure at one point of a sealed chamber will cause an equal increase at any other point within the same closed space. The principles might be hard to visualize, but all the science is describing is the potential an incompressible fluid has to move heavy loads when that space is properly sealed.

Let’s pause for a minute and transplant that abstract scientific notion into a real world scenario. The tubes and valves of a mechanical system are properly enclosed, a driving force is present, and an actuator is located somewhere within the system. Of course, when we refer to that pump, an engineer would be talking about a diesel-powered pumping mechanism or an impeller tied to an electric pump. On the other hand, if you talk to a doctor, he or she is bound to picture a heart. In any case, a manually operated or powered source of energy is used to compress the fluid within the chamber. A branching network of tubes extends this force evenly throughout the system, thus transmitting applied power to every point of a machine. One example of this configuration can be found in cranes and another can be seen in operation on the flaps of wings on an aircraft. Thus, small input energy is causing a big output of power.

The dramatic realization of the full power of hydraulics comes from the manipulation of pressure and flow. A powerful pump could charge a reservoir with litres of heavily pressurized hydraulic fluid and use a network of control valves and feedback loops to manage the flow. The result would be the amplification of applied power. Imagine turning a steering wheel or a control dial a half twist clockwise and watching a hydraulically controlled actuator move a multi-tonne load meters off the ground in response to this human-scaled action. This action and much more is possible with hydraulic power, a science that can be compared to electrical energy distribution. Electricity uses switches and cables, a processing environment that’s mirrored by control valves and the tubes that hold hydraulic fluid.

We’ve gotten this far without taking a close look at the label used in this fluid transmission principle. The word ‘hydraulics’ suggests a connection with water, and there’s some truth to this notion. Water was used as the transmission medium when the engineering principle was first discovered, but, as the technology came of age, it has adopted specialized hydraulics fluids that are less compressible and therefore more energy efficient than water. Finally, remember that this introduction offers a clarifying look at the building blocks of the energy transmission attributes behind fluid power, but there’s much more to discover including drive mechanisms, accumulator storage principles, and an entire library of differing actuator types.

### Mobile Hydraulic Specialties Pty Ltd

Keysborough, Victoria, 3173

Phone: (03) 9798-6511

Optimized by NetwizardSEO.com.au