Temperature is one of the most important factors affecting lubrication life. As the temperature increases, the viscosity of the grease base oil decreases. Based on the grease life calculated at 70°C, the life will be reduced by half for every 15°C increase in its operating temperature. The allowable operating temperature of the motor bearing should be the intersection of the allowable temperature range of the various parts of the bearing (the narrowest range), and only within this range can the safe operation of the bearing be guaranteed.

Therefore, whether the NSK bearing can operate in a high-temperature environment mainly depends on the choice of lubricant, followed by bearing sealing material (only for enclosed bearings) and cage, and finally bearing steel. The actual temperature generally measured in the application is the temperature near the outer ring of the bearing, and the difference between different measurement methods and positions can be up to 15°C.

Generally, the heat dissipation condition of the bearing seat is better than that of the shaft, so the temperature of the inner ring and rolling elements is 5~10℃ higher than that of the outer ring. Therefore, when the test location is outside the bearing chamber, if the measured temperature is 95°C, the hottest spot temperature of the inner ring may reach 120°C. It has reached the stable heat-resistant temperature of nylon cage, SKF deep groove ball bearing steel and grease.