1. Vibration of bearing

Bearing vibration is very sensitive to bearing damage, such as peeling, indentation, rust, crack, wear and so on, will be reflected in the bearing vibration measurement, so, through the use of a special bearing vibration measurement device (frequency analyzer, etc.) can be measured the size of the vibration, through the frequency division can not infer the specific case of abnormal.The measured values vary according to the use conditions of the bearings or the installation positions of the sensors, so it is necessary to analyze and compare the measured values of each machine before determining the judgment criteria. 

2. Bearing temperature

Bearing temperature, generally have bearing surface temperature can be inferred, if the use of oil hole can be directly measured bearing ring temperature, more appropriate.

Normally, the temperature of the bearing rises slowly with the running of the bearing and reaches a steady state after 1-2 hours.The normal temperature of the bearing varies with the heat capacity, heat dissipation, speed and load of the machine.If the lubrication and installation parts are suitable, the bearing temperature will rise sharply and there will be abnormal high temperature. At this time, the bearing must stop running and take necessary preventive measures. 

The thermal sensor can be used to monitor the working temperature of the bearing at any time, and realize the automatic alarm or stop to prevent the combustion shaft accident when the temperature exceeds the specified value. 

High temperature usually indicates that the bearing is in abnormal condition.High temperatures are also harmful to bearing lubricants.Sometimes bearing overheating can be attributed to bearing lubricants.If the bearing at more than 125℃ temperature for a long period of continuous transfer to reduce the bearing life.Causes of high temperature bearings include: insufficient or excessive lubrication, lubricants.Contains impurities, excessive load, bearing ring damage, insufficient clearance, and high friction caused by oil seals, etc.

Therefore, it is necessary to continuously monitor the bearing temperature, whether measuring the bearing itself or other important parts.If the operating conditions are unchanged, any temperature change can indicate that a fault has occurred.

The periodic measurement of the bearing temperature can be made by means of a thermometer, such as a SKF digital thermometer, which can accurately measure the bearing temperature and display it in units determined by ℃ or Fahrenheit.

Important bearings, meaning that when they are damaged, will cause the equipment to stop, so this type of bearings should be equipped with a temperature detector.

Normally, the bearing will have a natural temperature rise after lubrication or re-lubrication for a day or two.