## Basics of Hydraulic System in Engineering

It is indeed very tough to see any industry without a slight touch of hydraulic system. Hydraulic system is crucial for various industries as well as our daily life routine, but its’ importance are occasionally unrealized by many. One of the most common hydraulic system application is in our vehicle breaking system. I’ll explain further about the breaking system later in this article. Anyway, from my previous experiences, I worked with several types of equipments and machineries employing hydraulic system. Among them are tractors, crane hoist, robots, actuators and hydraulic motor. All of them are unique, special and fasten my assignments and team’s job.
Basically, a hydraulic system can be explained as one force that is applied to one point (or piston), and is then transmitted to another point via the use of an incompressible fluid. A hydraulic system confines the liquid so that it uses the laws governing liquids to transmit power to do specific work. Figure 1 illustrates the principle of hydraulic system.
Figure 1: Principle of hydraulic drive system (source).

Often, the fluid utilized to transfer the motion is typically a type of oil. Oil is in nature incompressible and is very efficient for the transfer of force and motion. A critical point to take into account is that a hydraulic system cannot contain any air. If air bubble appears in the system then the force applied to the piston would be used to compress the air bubble, instead of going on to move the subsequent piston. As a result, it affects the efficiency of the hydraulic system.

Let’s visualize the hydraulic system closely. A simple example of a basic piston-driven hydraulic system is the braking system of our typical car (refer Figure 2). When we hit/pressed the break to slow or stop the car, the brake pedal is depressed. It then pushes on the piston in the master cylinder of the brake. Other four slave pistons in each wheel actuate to press the brake pads against the brake rotor to slow or stop the car.

Figure 2: Typical breaking system in a car (source)

Principally, these systems normally involve equipment meant to handle heavier weights. This demands more physical strength as well as higher operating pressure for the system. Such hydraulic system operating pressure ranges from a few hundred pounds per square inch (PSI) to several thousand pounds per square inch.

Hydraulic systems offer advantages over other methods of power transmission. For instance, hydraulic systems have a simple design. In many cases, complicated mechanical linkages can be replaced with a few pre-engineered hydraulic components. These systems are also more flexible. The location of component in a system is extremely versatile. Instead of sedentary mechanical elements, flexible pipes and hoses used in these systems eliminate location problems. Additionally, these systems are also much more smooth and quiet while in operation. With high efficiency and minimum friction or interference, these systems keep the cost of power transmission at a minimum.

When working with hydraulic system and its associated fluid, we cannot afford to settle for less or mediocre quality. We must use one with high quality produced/delivered by reputable companies. Numerous companies are available in the market which provides hydraulic system and extensive areas of fluid technology expertise. The company I worked with before used hydraulic and lubricant oils from Hydac for most of the equipments and machineries. It was from them I learned more about the principle and application of hydraulic system and fluid technology. I must say I truly appreciate the knowledge, skill and experience delivered during their visit and discussion. It made me a better and more mature engineer.

posted by zaki yamani @ 9:36 AM,