1. Centralized feed system The lack of hydraulic oil tank, the air into the pump, resulting in oil bubbles produced by hitting the leaves, resulting in noise. Observe the amount of oil to prevent air from entering.
2. High viscosity of hydraulic oil, resulting in poor flow, increase resistance, resulting in noise, should be replaced by the appropriate hydraulic oil.
3. Centralized feed system pump or motor failure, bearing or blade damage will make the coupling concentric error, resulting in noise, should adjust the coupling concentricity.
4. Mechanical bearings wear or lack of machinery or mechanical parts loose, friction noise generated during operation, should be promptly added lubricants, good maintenance work.