Low temperature bearings Low temperature bearings are not the bearings that operate stably in high temperature environment as opposed to high temperature bearings, but they are the bearings that are designed with special materials and structure to reduce the friction factor and thus reduce frictional heat generation, so that the bearings remain low temperature during long time operation. Bearings with working temperature below -60℃ are low temperature bearings. They are mainly used in all kinds of liquid body pumps, such as liquefied natural gas pumps, liquid nitrogen (hydrogen, oxygen) pumps, butane pumps, liquid pumps for rocket missiles, space vehicles, etc. The operating temperature of low-temperature bearings reflects the material technology and processing level of bearing processing. Its measurement is mainly based on the temperature difference between the outer ring of the bearing and the injected cooling oil during operation as an indicator. Lower operating temperature means longer bearing life and higher performance. The world’s leading bearing manufacturers, relying on their respective advantages, trying to achieve comparative advantage in a number of areas of low temperature bearings. In the case of spherical roller bearings, for example, the operating temperature of high-quality products is about 15.5℃, while ordinary products are above 19℃. Low-temperature bearing product categories Low temperature bearings are mostly single row deep groove ball bearings and cylindrical roller bearings For the phenomenon of jamming of bearings at low temperature, the external factor is the change of temperature, and the internal factor is the different thermal expansion coefficients of shaft, frame and material. When the temperature range is large, the shrinkage rate of different materials is different, which leads to the gap becoming small and stuck. Therefore, it is necessary to calculate the coefficient of expansion of materials for equipment with a wide operating range, including those used at low temperatures, and also try to use materials with similar coefficients of expansion for better results. In addition, in the structural design, try to avoid the structure of using a tapered roller bearing at each end of the shaft. With this structure, the longer the distance between the two bearings, the greater the possibility of jamming. If one end of the shaft is mounted with a pair of tapered bearings, the axial movement of the shaft is restrained as the shaft is positioned, and the other end of the shaft is used with a rolling bearing, which only limits the radial force, and can move axially in the axial direction with the axial temperature in a certain range. Low temperature bearing bearing steel selection Low temperature bearing commonly used stainless steel bearing steel 9Cr18, 9Cr18Mo manufacturing, can also choose beryllium bronze, ceramic and other materials manufacturing; working temperature very low temperature conditions (limit temperature -253 ℃): the working limit temperature requirements in -253 ℃, can choose 6Cr14Mo material, but must be used in a vacuum environment. Note: In the use of low temperature bearings, attention should be paid to burns etc. caused by poor lubrication, so attention should be paid to the selection of suitable lubricants. List of bearing materials and working temperature High temperature bearings The withstanding temperature value of high-temperature bearings is mainly determined by the material of the bearings. 1. Temperature grade of high-temperature bearings (1) 0-600 ℃ high temperature bearings The general temperature level is divided into 200, 300, 400, 500, 600 ℃, the common temperature level is 300 and 500 ℃ two levels. (2) 600-800 ℃ high temperature bearings This high temperature bearings are generally divided into two kinds, full high temperature steel high temperature resistant bearings and ceramic hybrid high temperature bearings. (3) 800-1200 ℃ high temperature bearings Such bearings are generally silicon nitride ceramics as raw materials to replace the steel difficult to reach high temperature environment. 2. High-temperature bearing temperature classification (1) ordinary bearing steel high temperature resistance: 150-200 ℃ Its structure is full rolling body, short service life, high post-maintenance costs. (2) high-temperature alloy steel: 300-500 ℃ Its structure contains cage, full rolling body of two; life of more than one year, recommended. 3）Silicon nitride ceramic rolling body: 800-1200℃ Its structure full rolling body, long service life, higher cost. If your use of the environment does not exceed 500 ℃ can take the second material. The use of high-temperature bearings to choose in accordance with the actual application environment, for example: harsh environment, higher speed must be used containing cage, seal ring, high temperature grease, etc. 3. Structure classification 1）Conventional structure This structure of high temperature bearings because there is no cage, increase the number of rolling elements, greatly increase the bearing heavy load low speed characteristics, longer service life, applicable high temperature bearing temperature range of 0-800 ℃. But the shortage is that the limit speed of these high temperature bearings is low, generally not more than 100 r/min, the inner diameter size of the larger bearings will be lower. The categories that meet the conditions of such bearings are: deep groove ball bearings, spherical ball bearings, single row cylindrical roller bearings and outer spherical ball bearings. It should be noted that the high speed here is not the bearing can reach a very high limit speed, but relative to the “full rolling body high temperature bearings”, bearing clearance and other factors, generally can reach 70% to 80% of the national standard limit speed of ordinary bearings. Such bearings can withstand the temperature range of 600 ℃ or less. 2）All ceramic or mixed ceramic bearings Ceramic bearings can generally withstand very high temperature, the limit temperature can reach 1200 ℃. But only ceramic cage, graphite cage or no cage can be reached, mixed ceramic bearings (steel inner and outer ring and ceramic ball) can withstand a lower temperature, if with steel cage can only reach 600 ℃ limit temperature.  

We have rich experience on precision bearing manufacturing and are ranked NO.1 in China and NO.3 all over the world.

We can tailor the overall solution for the use of precision bearings.

HONB– Accountability & Innovation