Many modern construction machines are considered to be engineering marvels, yet most of their glory is owed to one simple thing called hydraulics. Every piece of modern construction equipment being used today, including knuckleboom trucks, cranes, loaders, and dumpers use this kind of system. Since this technology is so widely used, it is important to understand what hydraulics are and how they revolutionized modern construction.
Understanding the Basics
It is a fact that liquids are unable to be compressed. No matter how much pressure is applied, liquid will not change in volume; instead, it can only be moved and the pressure dissipated. Because it can never be compressed, it is an effective medium for transferring power. The science of hydraulics takes advantage of this unique property of liquids.
Imagine a syringe filled with water. When pressure is placed on the plunger, water is forced out of the small port at the other end at a high rate of speed. If the process is reversed and the same amount of water is introduced into the small inlet, the plunger will retract slowly yet still possess the same amount of power as when it was pressed. This is because the barrel has a larger diameter than the rest of the system which generates more force per area.
This system is made up of a number of components which include:
- Ram – The hydraulic ram resembles the syringe. It is the part that produces the actual power and can move tons of weight. Compared to the rest of the system, the ram has the largest diameter. This is because the pressure is defined by the force acting per unit area. The larger the cylinder of the ram, the greater the force it generates.
- Fluid – The hydraulic fluid is a special type of liquid that is introduced into this system. One important characteristic of this fluid is its inability to be compressed. This is important so that no energy is wasted once the pressure within the system is increased. This fluid is similar to the water in the syringe as it transmits the pressure coming from one end to the opposite end of the system.
- Lines – Hydraulic lines are special hoses constructed from a combination of steel and rubber; they are designed to withstand the extreme pressure of the fluid. They connect the pump and the ram together and allow continuous pressure from the pump to the ram. There are two lines that lead to a single ram; one provides pressure for extension and another for retraction.
- Pump – The hydraulic pump is the mechanical component that facilitates the flow of the fluid and increases the pressure in the system. In relation to the syringe illustration, the pump can be found at the small port. It forces the fluid at a high velocity rate towards the large diameter ram.
- Engine – The engine is the power house that puts the pump in motion. The rotational motion is transmitted to the hydraulic pump typically via a power take off (PTO). During operation, the engine has to be kept idling to keep the pressure from the pump consistent. This is also the reason why diesel engines are preferred because they are economical to run for long hours when compared to gas engines.
Importance in Modern Construction
Before hydraulic systems were popular in construction equipment, engineers had to rely on pulley systems and cables for the movement of articulated components such as booms. This pulley and cable system is still being used today in larger equipment such as tower cranes; for compact and mobile applications, it proves to be much too cumbersome. The hydraulic system serves as a worthy alternative and has since dominated the field and given birth to modern construction equipment such as knuckleboom trucks.
Compared to centuries ago, construction now can be done faster and more safely with the help of hydraulic systems. From preparing the work site to digging a foundation, delivering materials, and hoisting components as the building construction grows in height, the hydraulic system that makes work look easy can be understood!