Matters needing attention when adding grease to high-voltage motors!
March 21, 2022
High-voltage motor lubricating grease is of great significance to protect the bearing, prolong the service life of the bearing and ensure the normal operation of the motor; avoid the damage of the bearing and the "sweeping" of the motor, which causes the motor to burn out.
1. Type of grease There are many indicators of lubricating grease, mainly including: site penetration, colloidal stability, oxidation stability, mechanical stability, evaporation loss, water resistance and similar viscosity. Selecting the appropriate grease according to the characteristics of the motor is of great significance to the service life of the motor bearing and to ensure the normal operation of the motor. If two types of greases of different types are mixed, it is easy to cause mutual reactions, resulting in variation in the performance of the grease, a decrease in the lubrication function, and an increase in the temperature of the motor bearing. Motors with high temperature and high power should use extreme pressure high temperature grease. 2. Motor oil discharge pipeline Before adding grease, check the motor oil drain pipe, if there is no waste grease at the outlet of the oil drain pipe Or if the grease is little and dry, it may be that the conjunctiva on the surface of the grease is blocked and should be cleaned to avoid excessive oiling, increased friction, and excessive temperature rise, which will damage the bearing. 3. Motor refueling nozzle Before refueling, the refueling nozzle should be cleaned to prevent dust or foreign matter from entering the bearing chamber and causing bearing wear; after adding oil, the refueling nozzle should be closed and the sealing screw should be tightened.
4. The amount of lubricating oil added The amount of lubricating oil added has a great influence on the bearing temperature rise. Generally, the addition amount of low-speed motor is 2/3-3/4 of bearing capacity; high-speed motor is 1/2-2/3. It can be calculated simply with the following formula: G=0.005×D×B In the formula: G----Grease quantity g D----Bearing outer diameter mm B----Bearing width mm Of course, many aspects should be considered in actual work (refueling interval, loss, temperature), generally a little more. Pay attention when adding: If it is found that the oil drain pipe does not drain much oil, it means that the consumption is not much and can be added less; Add more. If the bearing temperature is high, oil should be added in two or more times. After oiling, the bearing temperature should return to normal before refueling for a second time, so as to avoid the excessive temperature rise of the motor bearing and affect the bearing life. 5. Temperature detection After adding new oil, the bearing generally has a temperature rise process: in summer, the temperature rise is generally within 2 hours, and then slowly falls back to normal, and the temperature rise will not exceed 20 degrees; Normal, the general temperature rise does not exceed 10 degrees. If the temperature rises too fast, or the fall time is long, it means that too much grease is added, and oil drainage should be carried out to protect the bearing. It should be noted that the bearing temperature should not exceed 95 degrees when the ambient temperature does not exceed 40 degrees. 6. Refueling cycle The refueling cycle is generally 3 weeks (500h). Of course, the refueling interval should be appropriately adjusted according to the operation and use environment of the motor.
