What causes the uncoordinated compound movements in the Doosan 220-7?
3 Answers
Uncoordinated compound movements in the Doosan 220-7 may be due to issues with the main pump pressure. Below is relevant information: 1. Manufacturer: The Doosan DH220-7 excavator is a high-performance best-selling model produced by Doosan Infracore, a subsidiary of the South Korean multinational Doosan Group. It incorporates extensive research into cutting-edge excavator technologies from Japan and the United States, combined with the company's own excavator production experience. 2. Performance: The Doosan DH220-7 excavator utilizes new hydraulic technology to efficiently utilize engine power, employs new coolant cooling technology to ensure sufficient cooling of engine water temperature, and adopts advanced electronic control technology to enhance the excavator's superior performance.
I think the uncoordinated compound movements of the Doosan 220-7 are mainly related to the hydraulic system. Having operated similar excavators for several years, I've found that this issue often occurs when the hydraulic oil is too dirty or insufficient. Contaminants mixed into the oil can clog the pump and valves, causing the movements to become unsynchronized. Neglecting regular maintenance, such as failing to replace the oil filter on schedule, is also a potential hazard. During operation, avoid overloading the system with continuous compound movements—performing actions like lifting the arm and tilting the bucket too quickly can overwhelm the system. Regularly check the oil level and cleanliness in the tank, and change the oil every few hundred hours of operation to prevent this problem. If the issue persists, it's best to visit a repair shop before the movements completely seize up. Maintaining proper system lubrication and adopting standardized operating habits can significantly reduce coordination issues.
When repairing such machines, common causes are issues with the hydraulic pump or control valve. After the hydraulic pump ages, unstable oil pressure prevents synchronized compound movements; a stuck valve spool can also easily cause delays. Sometimes, loose sensors or circuit connections lead to inaccurate feedback signals, affecting the entire operation sequence. I recommend first checking the hydraulic oil temperature and pressure to ensure they are normal—use a pressure gauge for measurement. Always preheat the machine for a few minutes before operation, waiting until the oil temperature reaches the working range before performing compound movements. Additionally, inspect all hose connections for leaks—this is crucial. Regularly replacing the seals on pumps and valves can extend their lifespan. If these simple self-checks don’t resolve the issue, professional diagnostic tools will be needed.
