What are the basic principles of hydraulic systems on heavy equipment?

Hydraulic systems are essential on heavy vehicles (loaders, excavators, cranes). Here are the basic principles:

Pascal's principle: Pressure applied to a confined fluid is transmitted equally in all directions. A small force on a small piston can lift a heavy load on a large piston: F2 = F1 × (A2/A1).

Main components:

• Hydraulic pump: Converts mechanical energy into hydraulic energy. Types: gear pump (most common, max pressure 3,000 PSI), piston pump (high pressure, 4,000-6,000 PSI)
• Control valves: Direct fluid to the cylinders. Proportional valves allow precise motion control
• Hydraulic cylinders: Convert pressure into linear force. Force = Pressure × Piston area
• Hydraulic filter: Protects the system from contaminants. Should be changed every 500-1,000 hours

Maintenance:

• Hydraulic oil level: check daily
• Maximum oil temperature: 80 °C (above that, viscosity decreases and wear accelerates)
• Oil change: every 2,000-4,000 hours depending on the manufacturer