(1). Bearing cooling water is interrupted.
(2). Deterioration of oil quality, unclean oil itself or deterioration of oil during operation. For example, the increase of water in the oil will increase the acidity of the oil, reduce the lubricating effect of the oil, corrode the bearing bush and increase the bearing temperature.
2. Phenomenon:Causes, Phenomena and Treatment Methods of Bearing Temperature Rise
(1). An alarm bell rang
(2). The hydraulic machinery fault light plate on the turbine side panel is on, the temperature of the instrument indicating the bearing temperature rises, and the signal relay acts.
(3). The black needle of thermometer dial (expansion thermometer) coincides with or exceeds the yellow needle.
(4). Send out the fault signal of bearing temperature rise.
When the bearing temperature rises, first judge whether there is misoperation. If it does rise, the following treatment shall be carried out:
(1). Check whether the cooling water pressure, water flow and pipeline system are normal. If the water pressure is low, the filter may be blocked and cannot be handled in time, it can be shut down for treatment. When it is confirmed that it can work, it can be put into use.Causes, Phenomena and Treatment Methods of Bearing Temperature Rise
(2). Check the oil pressure of the governor. If the oil pressure is low, the cooling water hydraulic valve may be closed.Causes, Phenomena and Treatment Methods of Bearing Temperature Rise
(3). Check whether the bearing has abnormal sound and whether the bearing swing is abnormal.Causes, Phenomena and Treatment Methods of Bearing Temperature Rise
(4). Take an oil sample to observe whether the oil color has changed, and test to see whether it has deteriorated. If the deterioration is confirmed, stop the machine and replace it with new oil.Causes, Phenomena and Treatment Methods of Bearing Temperature Rise
(5). Check whether the oil level of the oil gauge is normal. If not, check whether the oil drain valve of the oil tank is tightly closed. If it has been closed tightly, oil shall be added. If it is oil leakage from the sealant pad, it shall be shut down for treatment.
The working surface of the bearing is subject to alternating stress, which leads to failure. It mainly occurs on the working surface of the bearing, often accompanied by fatigue cracks.
This failure form first occurs at the maximum alternating shear stress below the contact surface, and then extends to the surface to form different spalling shapes. Its formation process and consequences are: pitting – pitting peeling – shallow peeling – deep peeling.
Bearing wear failure refers to the failure caused by the continuous wear of the metal on the working surface caused by the relative sliding friction between the surfaces. Wear failure can be divided into abrasive wear and adhesive wear.
Abrasive wear refers to the wear caused by the extrusion of foreign hard particles or hard foreign matters or wear debris on the metal surface between the working surfaces of the bearing and the relative sliding of the contact surface.
Adhesive wear refers to the uneven stress on the friction surface due to the micro protrusion or foreign matter on the friction surface. When the lubrication conditions are seriously deteriorated, the local deformation and friction micro welding of the friction surface are easy to be caused due to the heat generated by local friction. In serious cases, the surface metal may be locally melted, and the force on the contact surface will tear the local friction welding point from the substrate and increase the plastic deformation.
When wear failure occurs, there is continuous wear on the surface of the bearing, which leads to the gradual damage of bearing parts, and further leads to the loss of bearing dimensional accuracy and other related problems.
Its formation process and consequences are: wear – shape change – increase of fit clearance and change of working surface morphology – lubricant pollution – complete loss of lubrication function – loss of rotation accuracy of bearing and even failure of normal operation.