Views: 8 Author: Site Editor Publish Time: 2022-03-09 Origin: Site
For high temperature bearing, many people do not know very well, some people who have not used it, even the temperature grade of high temperature bearing is difficult to distinguish, in order to let more people understand the characteristics and use of high temperature bearing; the following details Explain the temperature grade and structure type of high temperature bearings, and the difference between high temperature bearings and ordinary bearings.
First of all, it should be noted that the temperature range of ordinary bearings. The conventional bearing material we use daily is GCr15 high carbon chromium bearing steel, which is a high carbon chromium bearing steel with less alloy content. After quenching and low temperature tempering, it has high hardness, uniform structure, good resistance to Grinding, high contact fatigue performance.
The maximum operating temperature of this type of bearing is 120 degree, so when the ambient temperature of the mechanical equipment is higher, a high-temperature bearing with better temperature resistance is required.
Temperature grade and classification of high temperature bearings
Temperature grade of high temperature bearing
The temperature classes for high temperature bearings are as follows:
(1), 0--600 high temperature bearings are generally divided into 200, 300, 400, 500, 600 temperature grades, and the commonly used temperature grades are 300 and 500 grades.
(2) 600--800 high temperature bearing This kind of high temperature bearing is generally divided into two types, full high temperature steel high temperature bearing and ceramic hybrid high temperature bearing.
(3) 800--1200 high temperature bearings These bearings generally use silicon nitride ceramics as raw materials to replace the high temperature environment that is difficult to achieve with steel.
Materials of high temperature bearings
The temperature classification of high temperature bearings is as follows:
1. High temperature resistance of ordinary bearing steel: 150-200 ℃ (its structure is full of rolling elements, the service life is short, and the later maintenance cost is high)
2. High temperature alloy steel: 300-500 ℃ (its structure includes cage and two full rolling elements; service life is more than one year, recommended)
3. Silicon nitride ceramic rolling elements: 800-1200 ℃ (its structure is full of rolling elements, long service life and high cost) If your operating environment does not exceed 500 ℃, the second material can be used.
The high temperature bearing method should be selected according to the actual application environment, such as: harsh environment, high rotation speed, must use cage, sealing ring, Top quality high temperature grease.
The structure classification
Conventional bearing structure
The high temperature bearing of this type of structure has no cage and increases the number of rolling elements, which greatly increases the characteristics of the bearing under heavy load and low speed, and has a long service life. The temperature range for high temperature bearings is 0--800. But the disadvantage is that the limit speed of this kind of high temperature bearing is low, generally not more than 100r/min, and the bearing with larger inner diameter will be lower. The categories that meet the conditions of this type of bearing are: deep groove ball bearings, self-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 very high limit speed, but relative to the "full complement high temperature bearing with rolling elements", which is affected by factors such as bearing clearance, it can generally reach 70% to 80% of the ordinary bearings limit speed. Such bearings can withstand a temperature range of less than 600 degree.
Full complement rolling element design
The design of high temperature bearing of this type has no cage and increases the number of rolling elements, which greatly increases the characteristics of the bearing under heavy load and low speed, and has a long service life. The temperature range for high temperature bearings is 0--800. But the disadvantage is that the limit speed of this kind of high temperature bearing is low, generally not more than 100r/min, and the bearing with larger inner diameter will be lower.
The categories that meet the conditions of this type of bearing are: deep groove ball bearings, self-aligning ball bearings, single row cylindrical roller bearings and outer spherical ball bearings.
All-ceramic or hybrid ceramic bearings
Ceramic bearings can generally withstand very high temperatures, and the limit temperature can reach 1200. 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, and if matched with steel cages, it can only reach the limit of 600 temperature, but due to the high hardness and light weight of the ceramic ball.
High speed and long service life can be achieved. In addition, there are 600-degree, 800-degree, graphite self-lubricating, stainless steel bearings, all-ceramic bearings, ceramic hybrid bearings and other new high-temperature resistant bearings, but because the manufacturer's respective codes will be slightly different, no detailed description will be given here.
The difference between high temperature bearings and general bearings
(1) If the parts of the bearing are made of bearing steel and treated by high temperature tempering, the post code is according to the regulations of JB/T2974 (the parts are tempered at high temperature and the working temperature can reach 150°C, and the code name is /S0; After high temperature tempering, the working temperature can reach 200°C, and its code is /S1; after high temperature tempering, the working temperature can reach 250°C, and its code is /S2; The working temperature can reach 300°C, and its code is /S3; the parts are tempered at high temperature, and the working temperature can reach 350°C, and its code is /S4).
(2) The parts of the bearing are made of heat-resistant steel, and the post code is in accordance with the provisions of JB/T2974 (the material is Cr4Mo4V, and its post code is /HN; the material is Cr14Mo4, and its post code is /HN1; the material is Cr15Mo4V , its post code is /HN2; the material is W18Cr4V, its post code is /HN3).
How to buy a suitable high temperature bearings
As a professional bearing manufacturer and exporter, we (China bearing manufacturer) produce and supply a variety of high-quality special/common bearings, such as high temperature bearings, insulated bearings, hybrid ceramic ball bearings, super precision bearings, high-precision spindle bearings, engineering machinery bearings, agricultural machinery Bearings, Spherical Bearings, Cylindrical Roller Bearings, Tapered Roller Bearings, Spherical Roller Bearings, Thrust Roller Bearings, etc. For bearing price, quality and technical problems, you can contact us, we will provide you with the perfect solution s solution.