Classification and levels of high temperature bearings-NEWS-BEARING SULOTION FROM SIRKEN Temperature grades and classifications of high-temperature bearings
1. Temperature grade of high temperature bearingsThe temperature grades of high temperature bearings are as follows:
(1) The general temperature grades of 0--600 high-temperature bearings are divided into 200, 300, 400, 500, and 600. The commonly used temperature grades are 300 and 500.
(2), 600--800 high temperature bearings. This type of high temperature bearings are generally divided into two types, full high temperature steel high temperature resistant bearings and ceramic hybrid high temperature bearings.
(3), 800--1200 high temperature bearings. These bearings generally use silicon nitride ceramics as raw materials to replace steel in high temperature environments that are difficult to reach.
2. Temperature classification of high temperature bearings
The temperature classification of high temperature bearings is as follows:
1. Ordinary bearing steel has high temperature resistance: 150-200°C (its structure is full of rolling elements, which has a short service life and high maintenance costs in the future)
2. High-temperature alloy steel: 300-500℃ (its structure includes a cage and full rolling elements; the service life is more than one year, recommended)
3. Silicon nitride ceramic rolling elements: 800-1200°C (its structure is full of rolling elements, long service life, and high cost) If your use environment does not exceed 500°C, you can use the second material.
The high-temperature bearing method must be selected according to the actual application environment, such as: harsh environment and high speed. It must contain a cage, sealing ring, and imported high-temperature grease.
3. Structural classification
1. Conventional bearing structure
Because the full ball bearing does not have a cage, the increased number of rolling elements greatly increases the bearing's heavy-load and low-speed characteristics. It has a longer service life and is suitable for high-temperature bearings with a temperature range of 0-800. However, the disadvantage is that the limit speed of this type of high-temperature bearing is low, generally no more than 100r/min, and it will be even lower for bearings with larger inner diameters. Categories that meet this type of bearing conditions include: deep groove ball bearings, aligning ball bearings, single row cylindrical roller bearings and outer spherical ball bearings.
It should be noted that the high speed mentioned here does not mean that the bearing can reach a high limit speed, but that relative to "full rolling element high-temperature bearings", affected by factors such as bearing clearance, it can generally reach 70 for ordinary bearings. % to 80% of the national standard limit speed. This type of bearing can withstand a temperature range within 600°C.
2. Full ceramic or hybrid ceramic bearings
Ceramic bearings can generally withstand high temperatures, and the ultimate temperature can reach 1,200. However, it can only be achieved with ceramic cages, graphite cages or no cages. The temperature resistance of hybrid ceramic bearings (steel inner and outer rings and ceramic balls) is lower. If paired with a steel cage, it can only reach the limit of 600. temperature, but due to the high hardness and light weight of ceramic balls.
It can achieve high speed and long service life. In addition, there are new high-temperature bearings such as 600-degree, 800-degree, graphite self-lubricating, stainless steel bearings, all-ceramic bearings, ceramic hybrid bearings, etc. However, since the manufacturer's respective code names will be slightly different, detailed descriptions will not be given here.
4. The difference between high temperature bearings and ordinary bearings
(1) If the bearing parts are made of bearing steel and treated with high-temperature tempering, their suffix code shall be in accordance with the provisions of JB/T2974 (the parts have been treated with high-temperature tempering and the working temperature can reach 150C°, and their suffix code shall be /S0; parts After high-temperature tempering treatment, the working temperature can reach 200°C, and its setting code is /S1; after high-temperature tempering treatment, the working temperature can reach 250°C, and its setting code is /S2; after high-temperature tempering treatment, the setting code is /S2. The working temperature can reach 300°C, and its setting code is /S3; the parts have been treated with high temperature tempering, and the working temperature can reach 350°C, and its setting code is /S4).
(2) The parts of the bearing are made of heat-resistant steel, and their suffix codes are in accordance with the provisions of JB/T2974 (the material is Cr4Mo4V, and its suffix code is /HN; the material is Cr14Mo4, and its suffix code is /HN1; the material is Cr15Mo4V , its suffix code is /HN2; the material is W18Cr4V, its suffix code is /HN3)
5.Notes
VA201 bearing for high temperature applications, equipped with a stamped steel cage, the bearing rings and rolling elements are manganese phosphated, the radial clearance is multiple C5 clearance, and uses polyalkylene glycol (PAG )/graphite mixture for lubrication
VA208 Bearings for high temperature applications with segmented graphite cage, bearing rings and rolling elements manganese phosphated and with multiple C5 radial clearances
VA228 Bearings for high temperature applications with crown graphite cage, bearing rings and rolling elements manganese phosphated and with multiple C5 radial clearances
