Requirements for bearing temperature under different standards
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GB3215-824.4.1 During operation of the pump, the maximum temperature of the bearings shall not exceed 80°C. JB/T5294-913.2.9.2 The temperature rise of the bearings shall not be more than 40°C above the ambient temperature, with the maximum temperature not exceeding 80°C. JB/T6439-924.3.3 When the pump is operating under specified conditions, the surface temperature of the internal bearings shall not be 20°C higher than the temperature of the medium being transported, with the maximum temperature still not exceeding 80°C. The surface temperature rise at the exterior of the surface-mounted bearing should not exceed 40 degrees above the ambient temperature. The maximum temperature shall not exceed 80. JB/T7255-94 5.15.3 Operating temperature of bearings. The temperature rise of bearings must not exceed 35 degrees above the ambient temperature; the maximum temperature must not exceed 75°C. According to JB/T7743-95, Section 7.16.4, the temperature rise of bearings must not exceed 40 degrees above the ambient temperature, with a maximum temperature limit of 80°C. Per JB/T8644-1997, Section 4.14, the temperature rise must not exceed 35 degrees above the ambient temperature, with a maximum temperature limit of 80°C. Regulations stipulate that for motor bearings, the maximum temperature for rolling bearings is 95°C, while for sliding bearings it is 80°C. Additionally, the temperature rise must not exceed 55°C (the temperature rise is calculated as the bearing temperature minus the ambient temperature at the time of testing) ； Causes and solutions for excessive bearing temperature rise (1) Cause: Bent shaft, inaccurate centerline. process ； Find the center again. (2) Reason: The base screw is loose. Treatment: Tighten the foundation screws. (3) Reason: The lubricating oil is not clean. Solution: Replace the lubricating oil. (4) Reason: The lubricant has been in use for too long and has not been replaced. Treatment: Wash the bearing and replace the lubricating oil. (5) Reason: Damage to the balls or rollers in the bearing. Solution: Replace with a new bearing. According to the **standards**, it falls under Class F insulation with Class B performance requirements; the motor’s temperature rise is to be controlled at 80K (using the resistance method) or 90K (using the component method). Considering an ambient temperature of 40 degrees, the maximum operating temperature of the motor must not exceed 120/130 degrees. The maximum allowable bearing temperature is 95 degrees. Use an infrared thermometer to measure the temperature of the outer surface of the bearing housing; empirically, the maximum temperature at the highest point of a 4-pole motor should not exceed 70 degrees. For the motor itself, no monitoring is required. After the motor is manufactured, under normal circumstances, its temperature rise remains essentially constant; it does not change abruptly or continue to rise during operation. Bearings are wear-prone components that require inspection.
This bearing temperature is not the maximum permissible operating temperature for the bearing; rather, it refers to the permissible operating temperature for the grease or lubricating oil inside the bearing. Use grease: When the temperature exceeds 120°C, special grease should be used. When the temperature rises to 200–220°C, the interval between re-lubrications should be shortened ； Use lubricating oil: When the oil bath temperature exceeds 90°C or the bearing temperature exceeds 200°C, special lubricating oil can be used. If the temperature is even higher, then high-temperature bearings made of special materials need to be considered.
I’ve learned it! Haha, in practice, as long as the temperature rises abnormally, it’s necessary to stop the pump promptly for maintenance: lol
These temperatures refer to different types of bearings; bearings can be either rolling or sliding. Another difference is the temperature measurement points, which can be either outside or inside the bearing.
Many standards have been updated now; it is recommended to update them.
These standards vary depending on the pump, so it is normal for there to be differences.
Generally, an ambient temperature of +40 is used.