If cavitation damages the cylinder block and cylinder liners of our small loader, it can cause cracks or even through-holes. This allows coolant to enter the cylinder and engine oil, significantly reducing the lifespan and reliability of our diesel engine.
The main cause of cavitation is cylinder liner vibration. When the piston reaches top dead center, the direction of the side pressure changes, causing the piston to swing from one side of the cylinder liner to the other, resulting in piston wobble. Because there is a thermal gap between the piston and cylinder liner, this piston wobble has an impact. This impact causes strong vibration of the cylinder liner.
When the cylinder liner wall vibrates, alternating stretching and compression occur in the water cavity, creating localized high pressure and vacuum bubbles in the water near the outer wall. Under high vacuum, coolant evaporates into bubbles. Some vacuum bubbles and air bubbles occur in tiny pinholes on the outer wall of the cylinder liner, or are forced into these pinholes by the vibration. When a vacuum bubble or air bubble ruptures under high pressure, a pressure shock wave is generated near the rupture zone. This shock wave can reach tens of atmospheres and impacts the cylinder wall. Frequent and repeated impacts cause rapid damage to the cylinder liner surface.
To prevent cavitation erosion, common methods include: reducing the clearance between the cylinder and piston to reduce cylinder liner vibration; using a longer piston skirt; increasing the cooling water flow rate and improving the water flow direction and cooling system structure; increasing the support stiffness of the cylinder liner; and improving the materials and manufacturing process of the cylinder liner to enhance its resistance to cavitation erosion.
The causes of cylinder cavitation erosion damage in small loaders are as described above. It is hoped that everyone will pay attention to these causes and take preventative measures to avoid this phenomenon in small loaders.
