Understanding Excavator Hydraulic Systems: A Beginner’s Guide

Excavator Hydraulic Systems

Excavators are marvels of engineering, capable of performing heavy-duty tasks with precision and power. At the heart of their impressive capabilities lies the hydraulic system. This complex network of components works together to generate the force required for digging, lifting, and maneuvering. This guide provides a beginner-friendly overview of excavator hydraulic systems, explaining how they function and the key components involved.

What is Hydraulics?

Hydraulics is the use of liquids under pressure to generate, control, and transmit power. In an excavator, hydraulic fluid (typically oil) is pressurized and used to move various components, including the boom, arm (stick), bucket, and tracks. The principle behind hydraulics is Pascal’s Law, which states that pressure applied to an enclosed fluid is transmitted undiminished to every part of the fluid and the walls ofits container.

Key Components of an Excavator Hydraulic System:

An excavator’s hydraulic system comprises several essential components working in harmony:

• Hydraulic Pump: The heart of the system, the hydraulic pump is responsible for generating the pressurized hydraulic fluid. Most excavators use piston pumps, which are highly efficient and capable of producing high pressures. The pump draws hydraulic fluid from the hydraulic tank and delivers it to the rest of the system.

• Hydraulic Fluid (Oil): The lifeblood of the system, hydraulic fluid transmits power throughout the excavator. It also lubricates moving parts, dissipates heat, and protects against corrosion. Different types of hydraulic fluids are available, each with specific properties suited for different operating conditions. Choosing the correct fluid is crucial for optimal performance and longevity of the system.

• Hydraulic Tank (Reservoir): The hydraulic tank stores the hydraulic fluid. It also allows air to separate from the fluid and helps dissipate heat. The tank is typically equipped with filters to remove contaminants. Maintaining the correct fluid level in the tank is essential for proper system operation.

• Control Valves: These valves regulate the flow and direction of hydraulic fluid to the various cylinders and motors. They are controlled by the operator through levers and pedals in the cab. Different types of valves are used in an excavator, including directional control valves, pressure relief valves, and flow control valves.

• Hydraulic Cylinders: These are the actuators that convert hydraulic pressure into linear motion. As explained in our other articles, they consist of a barrel, piston, piston rod, and seals. When pressurized fluid enters the cylinder, it pushes the piston, causing the rod to extend or retract, thus moving the boom, arm, or bucket. (Link to your cylinder maintenance/product pages here).

• Hydraulic Hoses and Fittings: These components connect all the various parts of the hydraulic system, carrying the pressurized fluid. They must be able to withstand high pressures and extreme temperatures. Regular inspection and replacement of hoses are vital to prevent leaks and system failures.

• Filters: Filters are crucial for keeping the hydraulic fluid clean and free of contaminants. They remove dirt, debris, and other particles that can damage components and reduce system efficiency. Different types of filters are used in the system, including suction filters, pressure filters, and return filters.

How the System Works:

1. The hydraulic pump draws fluid from the hydraulic tank.
2. The pump pressurizes the fluid and sends it through the hydraulic lines.
3. The control valves, operated by the excavator’s controls, direct the pressurized fluid to the appropriate cylinders or motors.
4. The pressurized fluid pushes the pistons within the cylinders, causing the piston rods to extend or retract.
5. This linear motion is then used to move the excavator’s boom, arm, bucket, and tracks.
6. Once the fluid has done its work, it returns to the hydraulic tank, where it is filtered and cooled before being recirculated.

Importance of Proper Maintenance:

Maintaining the hydraulic system is crucial for the excavator’s performance, reliability, and lifespan. Neglecting maintenance can lead to:

• Reduced efficiency: Contaminated fluid or worn components can reduce the system’s efficiency, resulting in slower operation and reduced power.
• Increased wear and tear: Contaminants can cause excessive wear on components, leading to premature failure.
• Costly repairs: Neglecting small issues can lead to major problems requiring expensive repairs and downtime.
• Safety hazards: Hydraulic system failures can create dangerous situations for the operator and those working nearby.

Conclusion:

Understanding the basics of excavator hydraulic systems is essential for anyone working with or managing these powerful machines. By ensuring the proper maintenance of each component, you can maximize performance, minimize downtime, and extend the life of your excavator. Contact WELY HYDRAULIC-WELY PARTS today for all your hydraulic cylinder needs and expert advice. (+86 18763856583).