Underground mining muck loader performance relies heavily on hydraulic pressure, which powers its loading and excavation systems. If the hydraulic oil pressure drops during operation, the underground mining muck loader may lose efficiency, causing delays and potential equipment damage. Understanding the reasons for low oil pressure is key to ensuring smooth operation and avoiding costly downtime.

1. Excessive Clearance Between Crankshaft and Bearings

Over time, continuous use of the loading bucket can increase the clearance between the crankshaft and connecting rod bearings in a wheeled underground mining muck loader. As this gap widens, the hydraulic oil wedge becomes weaker, resulting in pressure loss. For example, a 0.02 mm increase in clearance can reduce pressure by 0.02 MPa. To resolve this, the crankshaft should be ground and matched with properly sized bearings to restore proper assembly clearance.

2. Insufficient Oil Pump Output

If the hydraulic oil pump does not deliver enough oil, the underground mining muck loader will experience lower lubrication pressure. This issue often arises from excessive axial or radial gaps between the oil pump shaft and bushing, or between the gear end face and the pump cover. Reducing these tolerances or replacing worn components can restore normal oil flow and pressure.

3. Overheating Issues

Excessive operating temperatures can severely affect the underground mining muck loader’s hydraulic system. Causes may include a malfunctioning large-scale cooling system, prolonged overload in mini models, or mistimed fuel injection. High temperatures increase oil loss and reduce pressure. To correct this, ensure the cooling pipes are scale-free and adjust the fuel delivery timing for optimal operation under rated load.

4. Oil Pump Failure

If the oil pump drive gear or shaft pin becomes loose or falls off, foreign particles may enter the pump, jamming the gear mechanism. This results in complete pump failure and zero oil pressure. Fixing this issue involves reinstalling damaged pins or keys and installing an oil filter at the pump’s inlet to prevent debris from causing future damage.

Ensuring consistent hydraulic pressure is essential for the reliable operation of an underground mining muck loader. Regular inspection of clearances, oil pump efficiency, temperature control, and pump integrity can prevent pressure drops and maintain productivity. By addressing these issues early, operators can extend the service life of their underground mining muck loader and reduce downtime in underground mining operations.