Through the rational use of grease to reduce the influence of vibration and temperature on NTN needle bearing - bearing knowledge

Many factors affecting the bearing in real life, such as, temperature, vibration, etc. , these are all factors that influence the needle roller bearing to prevent the impact of these factors bring NTN bearing, the following main introduce everyone to vibration and temperature on the influence of the bearing: one, bearing vibration NTN bearing vibration damage sensitive, such as peeling, indentation, corrosion, cracks, wear, etc. Will be reflected in bearing vibration measurement, therefore, through the special needle roller bearing vibration is used ( Frequency analyzer, etc. ) The size of the measurement of vibration, frequency point cannot be inferred through the unusual situation. Measured values due to the sensor or bearing use? 吗? The conditions of the installation position is different, so you need to in advance of each machine analysis and measurements to determine the standard for comparison. Two, bearing temperature NTN bearing temperature, average bearing on the surface of the outdoor temperature can be concluded that if can directly measure the bearing outer ring temperature, is more appropriate. Generally, the temperature of the needle roller bearing running 1 - slowly began to rise 2 hours, in order to reach a steady state. For the heat capacity of the machine room temperature bearing, refrigerating capacity, speed and load changes. If the lubrication, install the corresponding department, NTN bearing is sudden temperature rise, there will be unusually high temperature, when to stop operation, take the necessary preventive measures. Temperature sensor can monitor the working temperature of the use of NTN bearing, and realize the temperature more than a specified value, in order to prevent the automatic alarm or stop the burning shaft accidents. The first it is bearing the viscosity of the grease NTN bearing grease is usually make a similar viscosity or apparent viscosity, said when, on the viscosity of grease must specify the temperature and shear rate. Similar viscosity index can be used to control the low temperature fluidity and pumping. The second is a measure of NTN bearing the low-temperature fluidity of the grease bearing grease performance at low temperature is one of the important index of low temperature torque, namely at low temperature ( - 20 ° c below) Needle roller bearing grease block low-speed flow degree of rotation, the low temperature torque by the starting torque of the grease and rotation torque after 60 mm average said. The third is the evaporative NTN bearing grease bearing grease evaporation ( C) Said in the long-term use under condition of high temperature grease, grease oil volatilization, evaporative as small as possible. The evaporative mainly depends on the nature of the lubricating oil and fat fractions. Fourth is bearing grease the oxidation stability of oxidation stability refers to the grease when used in long-term storage or long-term high temperature resistance to heat and oxygen, permanent changes in their ability to maintain its nature will not occur. Due to oxidation, are often free alkali content reduced or free organic acid content increases, drop point drop, dark appearance, appear different smell, consistency, ultimate strength, similar viscosity decreased, generated corrosive product and destroy the material of grease, soap oil separation. In long-term storage of grease, therefore, should be stored in dry and ventilated environment, prevent sun, and shall regularly check free base or free change of the project such as organic acid, corrosion resistance, to ensure its quality and performance. Fifth, bearing the thixotropy of the grease NTN bearing grease is the most basic features, is the thixotropy. When applying an external force, the flow of the grease in gradually become soft, the apparent viscosity decreased, but when at rest, after a period of time ( A very short) Again, the consistency ( Restore) This feature is called thixotropy. Decides the characteristics of grease, it can be at the site of the is not suitable for lubricating oil lubrication, and showed its excellent performance.