What are Low-Temperature Bearings?

Low-temperature bearings are a type of bearing engineered with specialized materials and structural designs to maintain stable operation under low-temperature conditions. In addition to differences in materials and construction compared to conventional bearings, they also reduce friction-induced heat generation by lowering the friction coefficient, enabling them to maintain low temperatures during prolonged operation. Below is a detailed introduction to low-temperature bearings.

I. What Are Low-Temperature Bearings?

1. Materials for Low-Temperature Bearings

Low-temperature bearings are typically manufactured using stainless bearing steels such as 9Cr18 and 9Cr18Mo. The bearing rings are made of G95Cr18 and G102CrMo stainless steels, or imported high-nitrogen stainless steels such as Cronidur®30 (X30 CrMoN15-2) and X.D15N.W (X40 CrMoVN16-2). The rolling elements are produced from G95Cr18 and G102CrMo stainless steels, or ceramic materials such as silicon nitride (Si₃N₄) and zirconia (ZrO₂). The cages are made of non-metallic or ceramic materials that offer self-lubricating, wear-resistant, and low-temperature-resistant properties, used in hybrid ceramic ball bearings. These materials are capable of functioning properly at operating temperatures as low as –253°C. For applications below –253°C, 6Cr14Mo material may be used, but it must be operated in a vacuum environment.

2. Types of Low-Temperature Bearings

The cryogenic bearings produced by MONTON are primarily available in deep groove ball bearing and angular contact ball bearing configurations. Detailed model specifications are provided below.

3. Application Fields of Low-Temperature Bearings

Low-temperature bearings are suitable for a wide range of equipment used to handle liquefied gases, such as natural gas pumps, liquid nitrogen pumps, liquid hydrogen pumps, liquid oxygen pumps, liquid pumps for rockets and missiles, and spacecraft. These devices operate at persistently low temperatures, where conventional bearings may fail. Low-temperature bearings are therefore essential to ensure reliable operation under such conditions.

II. Maintenance Methods for Low-Temperature Bearings

1. Daily Cleaning: The cleanliness of low-temperature bearings directly affects their lubrication performance. Contamination can hinder the formation of a lubricating oil film, accelerate lubricant degradation and aging, and impair lubrication effectiveness, ultimately shortening bearing service life.

2. Lubrication: During operation, attention must be paid to prevent overheating caused by inadequate lubrication. Therefore, selecting the appropriate lubricant is crucial. Insufficient lubricant supply may compromise lubrication performance and lead to seizure.

3. Regular Inspection: The cleanliness of the lubricating oil should be regularly monitored to determine whether replacement is necessary, thereby avoiding lubrication issues or other failures caused by contamination. If solid particles in the lubricating oil are smaller than 10 μm, the service life of the low-temperature bearing can be extended several times over.