GB/T 36221-2018 in English

3.1 Structure and size requirements

The structural design of the thin and ultra-light deep groove ball bearings for aviation motors focuses on lightweight and high rigidity. The inner and outer rings are both rounded ($r_{\mathrm{~a~}}$ and $r_{\mathrm{~r~}}$) to reduce stress concentration and increase fatigue life. The dimensional tolerance is strictly controlled above the 5th grade standard of GB/T 307.1 to ensure assembly accuracy and running stability.

3.2 Material Performance Analysis

The bearing rings and rolling elements are made of 95Cr18 and GCr15Z materials (Table 3), which have excellent high temperature resistance and wear resistance. 95Cr18 alloy steel performs well under high temperature and high load conditions, while GCr15Z provides better fatigue resistance. The sealing ring is made of fluororubber to ensure the sealing effect in extreme environments.

3.3 Lubrication Technical Requirements

Bearing lubrication is the key to ensure its long-term stable operation. According to the standard requirements, the bearing should be filled with high-performance grease that accounts for 30%-50% of the cavity volume (Table 4). It is recommended to use grease specified in MIL-PRF-27617D and MIL-C-11796. These lubricants are resistant to fuel and oxidants and are suitable for the working environment of aviation motors.

4.1 Recommendations for Standard Selection

• Select the appropriate size code according to the motor power and speed (Table 1)
• Grease that meets the MIL-PRF-27617D and MIL-C-11796 standards should be used preferentially
• 95Cr18 material bearings should be selected in high temperature environments

4.2 Maintenance and Monitoring

• Regularly check the bearing clearance (Table 2) and temperature rise performance
• Use vibration analysis and oil film thickness detection technology for status monitoring
• Replace failed or contaminated grease in time