Yaowu Cableway Song Jinlong

1. Hydraulic oil level is too low or oil quality has deteriorated

Reason: The oil tank is short of oil and air is exposed at the oil suction port, causing the hydraulic pump to be empty and unable to build pressure; the oil will be emulsified, oxidized, and have too many impurities after long-term use, destroying the viscosity and lubricity of the oil, causing increased internal leakage in the system and inability to increase pressure.

Treatment: Check the oil tank level gauge, add ropeway special anti-wear hydraulic oil to the specified level; replace with new qualified hydraulic oil, clean the oil tank, and replace the oil suction and oil return filters to eliminate air and impurities in the oil.

2. The hydraulic oil pump is worn, has serious internal leakage, and the volumetric efficiency is reduced.

Reason: The gear pump/piston pump has been running for a long time, the internal gear, plunger, and oil distribution plate are worn, the sealing surface gap becomes larger, the high-pressure oil directly flows back to the low-pressure side, and the pump outlet pressure cannot reach the rated value.

Treatment: Use a pressure gauge to measure the no-load and load pressures at the pump outlet. After confirming that the pump body is damaged, replace the hydraulic pump of the same model; inspect the oil suction pipeline to ensure that there is no air leakage or blockage, and that the pump absorbs oil smoothly.

3. The pressure regulation of the relief valve fails or the valve core is stuck or leaking

Reason: The pressure regulating spring of the relief valve is fatigued and broken, and the working pressure cannot be set; the valve core is stuck in the open position by impurities, or the sealing surface is worn, and the system pressure continues to be unloaded and is always in a low pressure state.

Treatment: Disassemble and clean the relief valve body and valve core to remove impurities; replace the damaged pressure regulating spring; re-adjust the pressure regulating screw clockwise to gradually increase the pressure to the rated working pressure of the cableway system and tighten the nut.

4. There is external leakage in hydraulic pipelines, joints and valve blocks.

Reasons: loose pipe joints, aging and damaged sealing rings, cracked oil pipes, high-pressure oil leaking directly to the outside, and continuous loss of system pressure.

Treatment: Check pipelines, flanges, and joints section by section, and tighten loose parts; replace aging and damaged O-rings, seals, and cracked oil pipes; perform a pressure maintenance test after repair to ensure there is no leakage.

5. The internal seals of cylinders, motors and other actuators are damaged and internal leakage is excessive.

Reason: The cylinder piston seal and guide sleeve are worn, and the hydraulic oil flows between the rodless chamber and the rod chamber of the cylinder; the hydraulic motor is internally worn, and the high and low pressure chambers are interconnected, making it difficult to build pressure in the system.

Treatment: Disassemble the actuator and replace it with a new sealing component; check the internal leakage of the cylinder/motor. If it exceeds the standard, replace the assembly directly, and conduct a no-load test run after installation.

6. The solenoid valve core is stuck or the seal fails, and cannot be closed in the unloading state.

Reason: The valve core of the reversing valve and unloading valve is stuck by impurities and is in the normally open unloading position; the sealing surface of the valve port is worn, causing continuous internal leakage and the system cannot maintain pressure.

Treatment: Disassemble the solenoid valve, clean the valve core and valve hole, and remove burrs and impurities; replace the damaged solenoid valve seal or directly replace the solenoid valve; test the action of the valve core with power on to ensure that the switch is in place and there is no internal leakage.

(Source: The serious things about the ropeway)