High-Temperature Resistant Bearing

In summary, any industrial process involving high temperature, friction, wear, or corrosion may be an application scenario for high-temperature resistant bearings.

Installation Precautions for High-Temperature Resistant Bearings

When installing high-temperature resistant bearings, the "hot mounting method" is the core, and the heating temperature must be strictly controlled while avoiding any form of striking.

Before Installation: Strict Inspection and Cleaning
● Inspection and deburring: Before installation, check the dimensions and precision of the shaft and housing bore to ensure no damage or burrs. If defects exist, repair with an oil file and polish with fine sandpaper.
● Thorough cleaning: Clean the shaft journal, bearing housing, and the bearing itself with gasoline, kerosene, etc. After cleaning, wipe dry and apply a thin layer of lubricating oil to facilitate installation.
● Note on sealed bearings: The interior of sealed bearings should remain as-is and not be cleaned.

Installation Method: Prioritize "Hot Mounting"
When the bearing inner diameter is greater than 70mm or the interference fit is large, hot mounting is strongly recommended.
● Heating equipment: Induction heaters are preferred (uniform, accurate temperature control); constant temperature ovens/electric furnaces or oil bath heating can also be used (the bearing should be suspended on a metal net 50-70mm above the bottom of the oil tank).
● Open flames and oil immersion strictly prohibited: Open flames or direct contact between the bearing and heat source are strictly prohibited.

Precise Control of Heating Temperature
● Recommended temperature: Typically heat to 80C - 100C.
● Absolute upper limit: Must not exceed 120C. Overtemperature may cause tempering of the bearing material, resulting in hardness and precision loss.
● After heating: installation should be quick and done in one go. After cooling, check whether the inner ring end face is tightly seated against the shaft shoulder.

Installation Prohibitions: Strictly Prohibit Violence
● Striking prohibited: Striking the bearing directly with hammers or other tools is strictly prohibited.
● Correct force application: Force must only be applied through specialized sleeves on the fitting ring end face. Force must not be transmitted through the rolling elements or cage.

Other Key Matters
● Lubrication and rust prevention: After cleaning and air-drying, add high-temperature lubricating grease; the fill quantity is typically 1/3 to 1/2 of the bearing internal space. Sweat can cause rust; wearing gloves is recommended during operation.
● Preload control: For paired angular contact ball bearings, preload must be strictly controlled to avoid excessive tightness causing heat at high speeds.

The core of installing high-temperature resistant bearings lies in "precise temperature control, strictly prohibit violence, and thorough cleaning."

FAQ

Q1: How to select high-temperature bearings with proper suffix?
A1: When selecting high-temperature bearings, confirm the actual operating temperature of equipment first. HT200 is for 200-230℃ working conditions, HT280 for 280-310℃, and HT500 high-temperature bearings are recommended for ultra-high-temperature environment of 480-520℃. Comprehensive selection shall also consider bearing type, C4/C5 clearance and lubricant medium to prevent premature bearing failure under high-temperature conditions.

Q2: Why are C4 and C5 large clearances preferred for high-temperature bearings?
A2: The rings and rolling elements of high-temperature bearings will thermally expand under continuous high-temperature operation. C4/C5 large clearance compensates dimensional changes caused by thermal expansion, avoiding seizure and stagnation caused by insufficient internal clearance, and ensuring stable operation of deep groove ball bearings, spherical roller bearings and insert bearings in high-temperature machinery.

Q3: Can ordinary grease be used for high-temperature bearings?
A3: Ordinary grease is not recommended. It tends to carbonize and dry out under high temperature. High-temperature grease or graphite lubrication must be adopted for high-temperature bearings. Both open-type and sealed high-temperature bearings need matched lubricants to extend service life.

Q4: What advantages do ceramic rolling elements have compared with steel rolling elements for HT500 high-temperature bearings?
A4: Ceramic rolling elements for HT500 high-temperature bearings feature superior high-temperature resistance, less hardness loss and excellent wear resistance at high temperature. Matched with alloy steel or graphite cages, they suit extreme high-temperature applications such as metallurgy and kiln furnaces, and effectively reduce thermal deformation of high-temperature bearings versus steel rolling elements.

Q5: What is the sealing difference between insert high-temperature bearings and ordinary high-temperature bearings?
A5: Insert high-temperature bearings adopt composite sealing structure, different from RS/ZZ seals for deep groove ball bearings. Composite seals block dust and high-temperature flue gas from entering bearing interior. They adapt to harsh high-temperature sites such as ovens and painting production lines, and guarantee long-term reliable performance of UC-series insert high-temperature bearings.