NTN bearing is a precision component, which needs to be carefully used. No matter how high-performance cylindrical roller bearings are used, if they are not used properly, the expected high performance will not be obtained. The following are some precautions for the use of bearings.
Effect of Precautions on Service life of NTN Cylindrical Roller Bearing
1、 Keep the bearings and their surroundings clean
Even if the fine dust invisible to the naked eye enters the NTN bearing, it will increase the wear, vibration and noise of the bearing. Cylindrical roller bearings and their surrounding accessories shall be kept clean, especially dust and dirt, tools and working environment.Effect of Precautions on Service life of NTN Cylindrical Roller Bearing
2、 Use and install carefully
It is not allowed to punch with force, directly knock the bearing with a hammer, or transmit pressure through the rolling element.Effect of Precautions on Service life of NTN Cylindrical Roller Bearing
3、 Use proper and correct installation tools
Use special tools as much as possible, such as special heaters and puller tools, and try to avoid using things such as cloth and short fiber.Effect of Precautions on Service life of NTN Cylindrical Roller Bearing
4、 Prevent bearing corrosion
When taking the bearing directly by hand, be sure to wash the sweat from your hands and apply high-quality mineral oil before operation. Pay special attention to rust prevention in rainy season and summer. However, under some special operating conditions, cylindrical roller bearings can obtain a longer life than the traditional calculation, especially under light load.
The premise of these special operations is that when the rolling surface (track and rolling parts) is effectively separated by a lubricating oil film and limits the possible surface damage caused by pollutants. In fact, under the ideal premise, the so-called permanent bearing life is possible.
There are many factors affecting the service life of NTN bearings, which can be roughly divided into service factors and internal factors.
Use factors mainly refer to whether the installation, adjustment, use and maintenance, maintenance and repair meet the technical requirements. The installation condition is one of the primary factors in the use factors. The improper installation leads to the change of the stress state between the parts of the whole set of cylindrical roller bearing.
The NTN bearing operates in an abnormal state and ends its service life early. Internal factors mainly refer to the three factors that determine the quality of bearings, such as structural design, manufacturing process and material quality.Effect of Precautions on Service life of NTN Cylindrical Roller Bearing
The manufacturing of bearings generally goes through multiple processing procedures. The rationality, advanced nature and stability of all the processing technologies will also affect the life of bearings.
The heat treatment and grinding processes that affect the quality of finished cylindrical roller bearings are more directly related to the failure of NTN bearings.
It is common for NTN bearings to fail during operation, so there is no need to make a fuss. The key is to judge and deal with the fault. Today, I will explain the common faults and troubleshooting methods of bearings. The reasons for the high temperature of needle roller bearing are: the quality of lubricating oil does not meet the requirements or deteriorates, and the viscosity of lubricating oil is too high; The mechanism assembly is too tight (insufficient clearance); The bearing assembly is too tight; The bearing race rotates on the shaft or in the shell; Excessive load; Broken bearing cage or rolling element, etc.
It causes the axis to deviate from the correct position and produces abnormal noise when the axis moves at high speed. When the bearing is tired, the metal on its surface will peel off, which will also increase the radial clearance of NTN bearing and produce abnormal noise.
In addition, insufficient lubrication of needle roller bearing, dry friction and broken bearing will produce abnormal sound. After the bearing is worn and loose, the cage is loose and damaged, which will also produce abnormal noise and damage to the bearing.
Noise related to bearing manufacturing: here includes cage noise and chatter. Cage noise mainly occurs in ball bearing and NTN bearing. When the bearing rotates, it will make sound due to the vibration of cage and the impact between cage and rolling element The sound is periodic Chatter (various bearings) is a sound with a certain frequency, which is produced by the vibration caused by large waviness on the raceway surface This phenomenon is a common problem, which needs more attention in the future.
Second, the noise caused by improper use: it exists for all kinds of bearings When NTN bearing raceway surface or rolling element surface is damaged, pitted or rusted, periodic noise and vibration will be generated Dirt noise will be generated when dust invades the bearing during operation This kind of noise is aperiodic and also accompanied by vibration. Its sound size is not fixed and sometimes not.
The third inherent noise: the sound of raceway and the sound of various bearings and rolling friction are the inherent sound of rolling bearings. The raceway sound is produced by the elastic characteristics of the rolling body when it contacts the raceway.
When the NTN bearing rotates, the rolling body rolls on the raceway and emits a continuous and smooth sound; Abnormal rolling friction sound can make uncomfortable abnormal metal friction sound such as “creak, creak”, which will not be made when the lubrication is good Therefore, it is not a problem in general. Attention should be paid only after the noise increases.
There are uneven pits on the contact surface between the raceway and the roller of NTN bearing, which indicates that the bearing has plastic deformation. The reason is that under the action of large static load or impact load, the local stress on the working surface of the bearing exceeds the yield limit of the material, which generally occurs on the needle roller bearing rotating at low speed.
The reasons for the cracks in the bearing race may be the tight fit of the NTN bearing, the looseness of the foreign or inner ring of the bearing, the deformation of the containing parts of the bearing, the poor surface processing of the installed bearing, etc.
Through the above analysis, now we all know and know how to deal with the noise of needle roller bearing. After that, I hope all NTN bearings used by you can operate without worry