Working Principle of Excavator Engine

    Excavator parts generally include maintenance parts, wearing parts and repair parts. The manufacturer shares the working principle of the excavator diesel engine:

Intake Stroke: Only pure air enters the cylinder. Due to low resistance in the diesel engine intake system, the pressure at the end of intake pa = (0.85–0.95) p0, higher than that of gasoline engines; temperature Ta = 300–340K, lower than that of gasoline engines.

Compression Stroke: Since only air is compressed, the compression ratio of diesel engines is higher (usually ε = 16–22). Pressure at compression end: 3000–5000kPa; temperature: 750–1000K, far exceeding the auto‑ignition temperature of diesel fuel (about 520K).

Power Stroke: Near the end of compression stroke, diesel fuel is injected into the combustion chamber at about 10MPa through the injector. It mixes with air quickly and ignites spontaneously. Cylinder pressure rises rapidly to 5000–9000kPa, maximum temperature 1800–2000K. Diesel engines are compression‑ignition engines.

Exhaust Stroke: Exhaust process is similar to gasoline engines, but with lower exhaust temperature, generally Tr = 700–900K. Single‑cylinder engines run unevenly with strong vibration because only one stroke outputs power. A large flywheel is required, increasing weight and size. Multi‑cylinder engines (4‑cylinder, 6‑cylinder, 8‑cylinder) are widely used to solve this problem.