Writer: Eric Bearing Limited
Recently, we found that many users have been consulting our high-temperature bearings, but after a careful question, we found that users do not need high-temperature bearings. Ordinary bearings can meet the requirements. It can be seen that users have the difference between ordinary IKO bearings and high-temperature bearings? What is the maximum temperature that ordinary bearings can withstand? I don’t understand it very well, so today we will explain this issue.
IKO bearings used at a working temperature above 150° are called high-temperature bearings. When the service temperature of chrome bearing steel exceeds 150°, its hardness will drop sharply and the size will be unstable, making the bearing unable to work normally. Therefore, for bearings whose working temperature is between 150° and 350°, if the rings and rolling elements are still made of ordinary high-carbon chromium bearing steel, the bearing parts must be subjected to special tempering treatment, which should generally be higher than the working temperature Tempering at 50°. The bearing steel that has been tempered according to the above requirements can be used normally at operating temperature. However, due to the decrease in hardness after tempering, the bearing life is reduced. When the bearing working temperature is higher than 350°, it must be made of high-temperature bearing steel.
In addition to the properties of general bearing steel, high temperature bearings should also have certain high temperature hardness and high temperature wear resistance, high temperature relief fatigue strength, oxidation resistance, high temperature impact resistance and high temperature dimensional stability.
When the IKO bearing rotates, the raceway surfaces of the inner ring and the outer ring of the bearing are in rolling contact with the rolling elements, so the running track is a dark surface. The running track attached to the raceway surface is not abnormal, so it can be obtained. Know the load conditions, so when disassembling the bearing, please pay attention to and observe the running track of the raceway surface.
Whether the bearing is installed correctly affects the accuracy, life and performance. Therefore, the design and assembly department must fully study the bearing installation. Hope to install in accordance with operating standards. The standard work items are usually as follows:
1. Clean the bearing and its related parts
2. Check the size and finishing of related parts
4. Inspection after bearing installation
5. Supply lubricant
Just before installation, open the IKO bearing package. General grease lubrication, do not clean, directly filled with grease. Lubricating oil is lubricated, and cleaning is not usually necessary. However, the bearings for instruments or high-speed applications should be cleaned with clean oil to remove the rust inhibitor coated on the IKO bearings. Bearings with anti-rust agent removed are easy to rust, so they cannot be placed in the air. For bearings that have been packed with grease, they can be used directly without cleaning.
What problems should be paid attention to when choosing IKO bearing types and types
Generally, the space in which IKO bearings can be installed is limited. In most cases, the shaft diameter (or bearing inner diameter) is based on mechanical design or other design constraints. Therefore, the choice of bearing type and size is determined by the inner diameter of the bearing.
Generally, the rated basic load is shown on the dimension table. However, axial load and radial load are also important factors in choosing a suitable bearing. When the size of the ball and needle roller bearings are the same, the needle roller bearings usually have a higher load capacity and can withstand greater vibration and shock loads.
The allowable speed is determined according to the bearing type, size, accuracy, cage type, load, lubrication method, and cooling method. The bearing table lists the allowable speed of standard precision bearings under oil lubrication and grease lubrication. Generally, deep groove ball bearings, self-aligning ball bearings and cylindrical roller bearings are suitable for high-speed operation.
IKO bearing tolerances, bearing dimensional accuracy and rotation accuracy are based on ISO and JIS standards. For machinery that requires high precision and high-speed operation, it is recommended to use IKO bearings with accuracy of 5 or above. Deep groove ball bearings, radial thrust ball bearings or cylindrical roller bearings are suitable for machinery with high operating accuracy.
When the contact surfaces of the rolling elements and raceways of IKO bearings are compressed, they will undergo elastic deformation. Some machines need to minimize elastic deformation. Roller bearings produce smaller elastic deformations than ball bearings. In addition, in some cases the bearing needs to be preloaded to increase rigidity. This program is usually used for deep groove ball bearings, radial thrust ball N bearings and tapered roller bearings. The inner and outer ring offsets, shaft bending, shaft or bearing housing tolerance changes, and matching errors will all cause the inner and outer ring eccentricity. In order to prevent the eccentric angle from being too large, self-aligning ball bearings, self-aligning roller bearings, or self-aligning bearing seats are better choices. IKO RNA 6908 needle roller bearings online , pls click here :
Installation and removal
Certain applications require frequent disassembly and installation to ensure regular inspection and maintenance. Bearings whose inner and outer rings can be installed separately, such as cylindrical bearings, needle roller bearings, and tapered bearings are very suitable for this occasion. The tapered hole type self-aligning ball bearing and self-aligning roller bearing also simplify the installation procedure with the help of the sleeve.