Introduce
YE5 series explosion-proof low voltage three-phase asynchronous motor
Frame number: H80-355
Capacity: 0.55~315kW
Number of poles: 2~8P
Voltage: 1140v and below
Analysis of cleaning requirements of motor bearings
When disassembling bearings for maintenance, first record the appearance of bearings, confirm the remaining amount of lubricant, and clean bearings after sampling and checking the lubricant. As a cleaning agent, gasoline and kerosene are generally used.
The cleaning of the removed bearing is divided into rough cleaning and fine cleaning, respectively, in the container, the metal mesh bottom is first placed, so that the bearing does not directly contact the dirt of the container. During rough cleaning, if the bearing rotates with dirt, it will damage the rolling surface of the bearing and should be paid attention to. In the crude cleaning oil, use a brush to remove grease and adhesion, roughly clean, transfer to fine washing.
Fine washing is to carefully clean the bearing while rotating in the cleaning oil. In addition, the cleaning oil should be kept clean frequently. The motor should generally be cleaned and refueled after 2000 hours of use. There are two cleaning methods for bearings:
1), hot oil cleaning method due to the use of a long time, soft dry oil or anti-rust paste hardened bearings, should be immersed in 100-200 ℃ hot oil, clamp the bearing with pliers, brush clean the oil on the bearing. Soft dry oil or anti-rust paste is heated to 100-200 ℃ to melt, it is easy to wash out from the gap in the bearing. Sometimes just shake the bearing in the oil several times. Oil can also flow through the crevices.
When cleaning the radial spherical bearings of the old motor or imported motor, the ball, the bead frame, the inner ring should be turned out of the outer ring and then immersed in hot oil, and the roller, the bead frame, the inner ring and the outer ring should also be removed when cleaning the short cylindrical roller bearings.
When cleaning the hot oil, the temperature of the oil should not exceed 20℃.
2), the general cleaning method put the bearing in kerosene for 5-10 minutes, hold the inner ring with one hand, turn the outer ring with the other hand, and the dry oil or rust cream on the bearing will fall down. Then put the bearing into the cleaner kerosene, wash with a soft brush, wash the oil in the ball and the gap, and then put it in the gasoline to clean once, and put it on a clean paper. When cleaning the radial spherical ball bearings and short cylindrical roller bearings, the ball, the bead holder, the inner ring and the outer ring should be removed for cleaning.
The cleaning of the bearings installed on the shaft mainly depends on the method of spraying oil or oil gun injection, and the oil that is easy to clean off is first used kerosene and then gasoline; The oil that is difficult to clean off, first wash with 100-200 ℃ hot oil or oil gun injection, and then clean with gasoline. Be sure not to scrape the bearing with sharp tools: hard grease or rust, so as not to damage the finish of the bearing rolling body and groove ring parts, clean the bearing with a clean cloth dry.
Motor and pump bearing temperature standards
Bearing temperature standard – pump bearing temperature standard
1，GB3215 4.4.1 During the pump operation, the maximum temperature of the bearing does not exceed 80℃
2, JB/T5294 3.2.9.2 Bearing temperature rise shall not exceed the ambient temperature 40, the maximum temperature shall not exceed 80℃
4.3.3 When the pump operates under the specified working conditions, the external surface temperature of the built-in bearing should not be higher than 20 ° C of the conveying medium temperature, and the maximum temperature should not be higher than 80 ° C. The temperature rise of the external surface of the external bearing should not be 40℃ at the high ambient temperature. The maximum temperature is not higher than 80℃
4, JB/T7255 5.15.3 bearing temperature. Bearing temperature rise shall not exceed the ambient temperature of 35 ° C, the maximum temperature shall not exceed 75 ° C
5, JB/T7743 7.16.4 Bearing temperature rise shall not exceed the ambient temperature of 40℃, the maximum temperature shall not exceed 80℃
4.14 Bearing temperature rise shall not exceed the ambient temperature of 35 ° C, the maximum temperature shall not exceed 80 ° C
Motor bearing temperature regulation, abnormal causes and treatment
According to the regulations, the maximum temperature of rolling bearings does not exceed 95 ° C, and the maximum temperature of sliding bearings does not exceed 80 ° C. And the temperature rise does not exceed 55℃ (temperature rise is the bearing temperature minus the ambient temperature at the time of testing);
(1) Reason: axis bending, center line is not allowed. Deal with; Find the center again.
(2) Cause: The foundation screws are loose. Solution: Tighten the base screws.
(3) Reason: lubricating oil is not clean. Treatment: Replace the lubricating oil.
(4) Reason: lubricating oil used for too long, not replaced. Treatment: Clean the bearing and replace the lubricating oil.
(5) Cause: The ball or roller in the bearing is damaged.
Treatment: Replace the new bearing. According to the national standard, F class insulation B class assessment, motor temperature rise control in 80K (resistance method), 90K (component method). Considering the ambient temperature of 40 ° C, the maximum operating temperature of the motor cannot exceed 120/130 ° C. Bearing temperature is allowed up to 95 degrees. The temperature of the bearing outdoor surface is measured with an infrared detection gun. Empirically, the highest point temperature of the 4-pole motor cannot exceed 70 ° C. For the motor body, no monitoring. After the motor is manufactured, under normal circumstances, its temperature rise is basically fixed, and will not mutate or grow with the motor operation. The bearing is a wearing part and needs to be tested.