Hydraulic Systems

A hydraulic system is a drive technology where a fluid is used to move the energy from one location to another. The basic principle behind a hydraulic system is rather quite simple. Force is applied at a point is transmitted to another point through an incompressible fluid. The fluid is usually some kind of oil. In this process, the force can be multiplied by many times which enables the operator to perform significant work with a minimum application of force. Hydraulic systems are found in a wide variety of applications, from small assembly processes to large industrial units.

A simple hydraulic system consists of two pistons and connected by a pipe filled with oil.  If you apply a downward force to one piston then the force is transmitted through the oil in the pipe to the second piston. Since the fluid is incompressible, therefore very little energy is lost and almost all of the applied force is transferred to the second piston. The pipe connecting the two cylinders can be fixed or flexible of any length and can go around things separating the two pistons.

In hydraulic systems, it is quite easy to add force multiplication (or division) to the system by simply changing the size of one piston and cylinder relative to the other. In most hydraulic systems, the cylinders and pistons are connected through valves to a pump supplying high-pressure oil. Because the hydraulic fluid is nearly incompressible the transmission of power is almost instantaneous.

Hydraulics is an intrinsic part of the following industries:

Automobile Industry

If you own a car, then you utilize hydraulics every day when you drive. The car brakes are a good example. As the brake pedal is depressed, it pushes a piston of the master cylinder. There are four slave pistons, for each of the four wheels, which actuate the brake pads against the wheel to stop the car.

In automobile factories, hydraulic presses stamp sheets of metal into the appropriate shape. They use hydraulic pressure, to form, trim, emboss and make the various parts for an automobile. Hydraulics machines are an intrinsic part of automobile, manufacturing industry.

Aerospace Industry

Almost all airplanes use hydraulics as they fly or take off or land. In an aircraft, hydraulics is responsible for activating flaps, landing gear, and brakes. Since aircrafts safety is of utmost importance, most hydraulic systems are designed as redundant systems.

Manufacturing

Die casting shapes the metal parts that we use today. Under high pressure, molten metal is forced into a reusable cavity so that it conforms to the desired shape. Most machines used in die casting are hydraulic based. Manufacturing uses a lot of robots. Most industrial robots use some kind of hydraulic system in their design.

Marine Applications

Hydraulics is utilized in the marine industry, particularly for ocean-going vessels. Most ships use a two-part system made up of a cylinder unit and a helm unit. Whenever the wheel is turned, hydraulic oil moves to a cylinder, which moves a rod based on the wheel’s direction and turns the rudder. Thus very large and heavy ships are navigated easily.

Construction Work

Large construction projects use hydraulics based machinery. A backhoe, for instance, utilizes hydraulics to lift large amounts of dirt or debris. There are many other applications of hydraulics in the construction field such as dumper trucks, bulldozers, lifts, concrete pumps, excavators and so many more earth moving machines.

Agricultural Fields

Farmers use a hydraulic three-point hitch for attaching equipment to tractors, such as plows. Many tractors, harvesters, and trucks use hydraulic systems to work efficiently. Using hydraulics a farmer can work efficiently and grow agricultural products economically and efficiently.

Entertainment

Rollercoasters and many types of swings in an entertainment park are hydraulic based.  Hydraulics are used in the entertainment industry for everything from hidden platforms in stages or on sets for special effects. Most movie cameras are operated on hydraulic based dollies.

Common Causes of Hydraulic Failure:

Air Ingress

Air ingress into a hydraulic system is a serious problem and can cause much damage to the hydraulic system over time. It wears down the pumps and other components resulting in overheating and making the system inoperative.

Water Contamination

Water contamination is also a big issue in hydraulic systems. It is often caused by leaks or condensation in the system. Water degrades the hydraulic components over time through oxidation and freeze-damage. If the hydraulic oil appears milky then it indicates water contamination. This is a serious issue and should be addressed immediately.

Temperature Problems

Hydraulic systems that run too hot or too cold can cause severe problems over time. Some of these challenges include the following.

• Fluid thinning: If the temperature of the fluid rises above the limits of the specifications then it will cause the hydraulic fluids to thin. This will prevent lubrication and possibly cause a fluid leak.
• Fluid oxidization: Very high temperatures can cause hydraulic fluid to oxidize and thicken. This can cause corrosion buildups, blockages, and reduced flow.
• Fluid thickening: In case of extremely low temperatures the viscosity of hydraulic fluid will increase restricting flow to reach the pump.

Fluid Levels and Quality

Low fluid levels and bad fluid quality can affect hydraulic system performance significantly. Poor filtration can result in air contamination and can cause high-temperature problems. Fluid leaks must be fixed urgently as they reduce the fluid levels very quickly. Using the correct type of fluid is also essential, as each hydraulic system has different demands of fluid viscosity and temperature tolerance.

Human Error

Often the human error is the main cause of many hydraulic system problems. Some of the most common errors may include the following:

• Faulty installations: Poor installation of any component in a hydraulic system can result in major problems. All installations must be done by expert technicians otherwise a minor error in installation can lead to complete failure of the system.
• Abrasion and Hose Tears: The hose assemblies need to be installed in a way that will minimize contact with other components in the system, otherwise the hose will rub against mechanical components and cause premature hose failure. When the hose fails, the whole system fails.
• Incompatible parts: A installation of mismatched components can result in system failure. For example, a pump may have a motor that runs beyond its maximum drive speed.
• Improper maintenance or usage: Using a system beyond its operating limit or failing to perform regular maintenance is often a cause of hydraulic system failure.

Failure of hydraulics is a serious issue in critical functions. Although very reliable, redundant hydraulic systems are used wherever safety is a critical issue.

Hydraulics systems are the backbone of modern machinery and so many industries rely on hydraulics for success. Hydraulic systems ensure safety, reliability, and efficiency which is the reason for its popularity and worldwide use.

e2b calibration is an ISO/IEC 17025:2017 accredited laboratory. We specialize in cost-effective repair and maintenance services of all types of hydraulic systems. We are registered with ANAB. We are also ANSI/NCSL Z540-1-1994 certified. Please contact e2b calibration for preventive and maintenance services for your ground support equipment.