How Does Hydraulics Work?

If you are wondering, “how does hydraulics work?” we have compiled some valuable information for you here.

Hydraulics is the science of transmitting pressures and forces via liquids. “Hydros” is ancient Greek for “water”. A characteristic feature of hydraulics is its ability to generate very large forces.

How Does Hydraulics Work? The Basics.

Hydraulics utilizes a property of liquid media. Unlike gases, liquids cannot be compressed. This means that in a closed hydraulic system, the same pressure prevails at every point. This greatly simplifies the construction of hydraulic systems. Unlike cable pulls or levers, hydraulic lines can be laid practically anywhere and routed optimally to the respective actuators.

Components of a Hydraulic System

• Hydraulic Tank
• Pressure Generator
• Consumer
• Lines
• Valves

The medium, usually hydraulic oil, is filled into the hydraulic tank. The oil flows past a check valve and to a pressure generator. This pressurizes the hydraulic system behind the check valve. The lines transmit this pressure to the actuator, which performs its intended work. When the valve is reset, the hydraulic system depressurizes again. The oil flows back into the tank, and the actuator returns to its initial position. A typical example of such a basic hydraulic system is a hydraulic jack. A small piston serves as the pressure generator, continuously transferring pressure into the hydraulic system. This pressure is absorbed by the slave cylinder of the jack. The piston of the slave cylinder extends proportionally to the immersing master cylinder of the pressure generator, so the pressure always remains constant. Once the slave cylinder reaches its end position, further pressure application is no longer possible. In this case, an overflow valve prevents overpressure from causing damage.

Force Amplification with Hydraulics

One of the greatest advantages of hydraulics is its ability to generate high forces. Force amplification occurs proportionally to the cross-sectional areas of the pistons of the master and slave cylinders. Master cylinders are significantly smaller than slave cylinders. Due to their small cross-section, their pistons can immerse deeply into the pressure tank of the hydraulic system. The pressure is immediately distributed over the effective surface of the piston in the slave cylinder. The piston yields to the pressure and extends. Although the travel distance of the extending piston is significantly shorter than that of the immersing master cylinder, the slave piston extends with a proportionally higher force. To bring the slave piston to its end position, the master piston must immerse accordingly often. This explains why a simple jack can lift a vehicle weighing tons. Regardless of how complex or extensive a hydraulic system is, these basic principles always remain the same.