Bearing the length of life, under normal circumstances by the material and technology of these two factors.
Bearing material largely determines the service life of the bearing, once the bearing metallurgy quality is the main reason for the early failure of rolling bearings. Bearing material on the impact of life, a substantial increase in metallurgical technology, bearing steel and other materials have emerged, has been greatly improved.
Bearing failure analysis, the proportion of bearing failure caused by raw materials has dropped significantly, but the material is still an important cause of bearing failure, but also the main bearing life constraints.
Bearing manufacturing process is complex, to go through many processes before they can get the finished product, of which forging, heat treatment, turning and grinding technology and the completion of the technical capacity and quality will affect NTN bearing life and application effects, especially heat treatment and Grinding process, it is the direct cause of many bearing failure, the need to get the manufacturer's attention.
After the bearing is installed, in order to check the installation is not correct, to carry out the operation check. Small machines can be rotated by hand to determine if they are spinning smoothly. Inspection items due to foreign body, scars, indentation caused by poor operation, due to poor installation, the installation of poor processing of the moment instability occurs, due to clearance is too small, the installation error, the friction caused by excessive torque Wait. If there is no exception, you can start the power running.
Large-scale machinery can not be manually rotated, so immediately after no-load power cut off the power, the machine idling, check for vibration, noise, rotating parts are not in contact, etc., to determine no exception, into the power running.
Power running, starting from no-load low-speed, slowly upgrade to the precondition of the rated operation. Test run during the inspection, is not abnormal sound, bearing temperature changes, lubricant leakage or discoloration and so on. If found to be abnormal, immediately stop running, check the machine, if necessary, remove the bearing inspection.
The temperature of the bearing can usually be estimated from the outside temperature of the housing. However, the use of direct measurement of oil hole NTN bearing outer ring temperature more accurate. Bearing temperature, gradually increased from the start of operation, usually 1 to 2 hours after the temperature stability. If the bearing installation is not good, the temperature will rise sharply, resulting in abnormal high temperature. The reasons for such as excessive lubricant, bearing clearance is too small, poor installation, sealing device friction is too large. High-speed rotation of the occasion, the bearing structure, the choice of lubrication error is also the reason.
Rotating sound of the bearing is checked with a stethoscope, etc., and there is a strong metal noise, abnormal sound, irregular sound, etc., indicating abnormalities. The reasons for poor lubrication, poor precision shaft or bearing, bearing damage, foreign body into such.