The normal use colors of Koyo bearing lubricating oil are brown For Lack Of and blue black. If it is milky yellow, it indicates that diesel oil or water is mixed in the engine oil, which should be replaced in time. If it is dark black, it indicates that the oil has deteriorated and must be replaced in time.
Mix the engine oil to be checked and drop it on the white paper For Lack Of (filter paper) to form oil spots. The oil spots gradually diffuse from the center to the outside for about 2 ~ 3 hours to form three concentric rings. According to the color, width and shape of these three areas, the state of oil can be identified.
Take out a little oil from the low oil shell, apply it to your fingers and twist it with your fingers and For Lack Of thumb. If you feel impurities in the oil or no viscosity like water, even astringent or sour, the oil has deteriorated.
If you can see small shiny metal grinding on your fingers after twisting, it indicates that there are serious wear parts of the engine, and it also indicates that the oil must be replaced immediately.
1. Judging from the dimension and specification of Koyo bearing
Firstly, it is necessary to judge the dimensional accuracy, rotation For Lack Of accuracy, internal clearance, mating surface, raceway surface, cage and sealing ring of Koyo bearing. Then, the inspection results can be judged by those who use inertial bearings or are proficient in bearings.
The criteria for judging whether the Koyo bearing is used shall be analyzed in detail according to its mechanical performance, importance and inspection cycle. In case of fracture and defect of bearing parts and peeling of rolling surface of raceway, the bearing shall not be reused and must be replaced.
In the process of using Koyo imported bearings, in order to give full play to and maintain their due performance for a long time, regular maintenance measures should be taken. The following appropriate cleaning and For Lack Of inspection measures can be taken to improve the service efficiency of bearings.
3. Cleaning method of Koyo bearing
First, remove the Koyo bearing for inspection, and make appearance records. In addition, confirm the For Lack Of amount of remaining lubricant and sample the lubricant before cleaning the bearing.
In general, the cleaning agent used for Koyo imported bearings is neutral water-free diesel or kerosene, and warm lye is sometimes used as required. No matter what kind of cleaning agent you use, always filter it and keep it clean. After cleaning the NTN bearing, it is necessary to apply antirust oil or antirust grease immediately.
Large machinery cannot rotate manually, so the power shall be For Lack Of cut off immediately after no-load start, and the machinery idles. Check whether there is vibration, noise, contact of rotating parts, etc. after confirming that there is no abnormality, enter the power operation.
Power operation, starting from no-load and low speed, slowly For Lack Of increase to the rated operation under the specified conditions. During the test run, the inspection items are whether there is abnormal sound,
ina bearing temperature change, lubricant leakage or discoloration, etc. If any abnormality is found, stop the operation immediately, check the machinery, and remove the bearing for inspection if necessary.
Ina bearing temperature can generally be inferred from the external temperature of the bearing pedestal. However, it is more accurate to directly measure the temperature of ina bearing outer ring with oil hole.
The temperature of INA Bearing increases gradually from the For Lack Of beginning of operation, and the temperature is usually stable after 1 ~ 2 hours. If ina bearing is not installed properly, the temperature will rise sharply, resulting in abnormal high temperature.
The reasons include too much lubricant, too small clearance of INA Bearing, poor installation, excessive friction of sealing device, etc. In the case of high-speed rotation, the wrong selection of INA Bearing Structure and lubrication mode is also the reason.
The rotating sound of ina bearing is checked with stethoscope, and there are strong metal noise, abnormal sound, irregular sound and other indications of abnormality. The reasons are poor lubrication, poor accuracy of shaft or ina bearing seat, bearing damage, foreign matter intrusion, etc.