The rolling bearing needs to add grease at any time to replace the grease that has deteriorated, exuded and contaminated NTN bearing. Due to the ever-changing operating conditions of rolling bearings, on-site proprietary technology is required to determine the appropriate grease addition interval from once a day to once a year. There is no grease or grease addition plan that can take into account all load, speed and operating temperature conditions in which a bearing shows excellent performance.
There are many factors affecting the frequency of grease addition. Generally speaking, the smaller the bearing and the faster the speed, the lower the frequency of grease addition. The larger the size and the slower the speed of the bearing, the more frequent the addition of grease is required. The main factors are as follows:
Different types of bearings require different greasing frequencies:
Radial ball bearing = fundamental frequency.
Cylindrical roller bearing = 5 times the basic frequency.
Thrust rollers and roller bearings = 10 times the operating temperature of the basic frequency
Higher temperature increases the oxidation rate of grease. When it exceeds 150 ° f (65 ° C), the oxidation rate of grease will double for every 18 ° f (10 ° C). For example, one bearing operates at 250 ° f (120 ° C); Compared with a bearing operating at 150 ° f (65 ° C), the former usually adds grease 10 times more frequently than the latter.
In addition, as the temperature increases, the grease begins to soften and may become fluid and leak out of the bearing housing.
High temperature operation requires higher grease addition frequency; High temperature grease can reduce this frequency.
Environmental conditions: if the bearing operates in a polluted environment, the greasing frequency needs to be increased.
Be sure to indicate any abnormalities in the lubrication report, such as high temperature, noise, vibration or leakage of the bearing.
Many rolling bearings require a small amount of grease to be added at the grease flushing interval. Add lubricating grease and use low-pressure oil gun. If the seal is in good condition, reduce the amount and frequency of grease injection.
1) Check the grease stock in the bearing – remove the pipe fitting or grease drain plug and check whether there is excess grease flowing out.
2) Check the bearings and seals for excessive leakage.
3) A few “injections” for each fat addition are sufficient. Do not add too much grease!
For grease flushing, the following “decompression” methods are recommended.
1) Remove the lower oil drain plug; Clean out all hardened grease.
2) Wipe off the grease fittings.
3) Pump the grease into the pipe fittings until all the old grease is replaced and new grease appears. Under safe and feasible conditions, the machine can be operated while performing this task.
4) Allow the machine to operate at operating temperature while removing the drain plug. In this way, the grease can be evenly distributed and the excess grease can be squeezed out through the oil drain orifice plate, so as to release the internal pressure. When the bearing housing reaches the normal pressure (about 10-30 minutes), the excess grease will stop discharging.
1) Under the condition of ensuring safety, remove the pipe fittings while the equipment is running at the operating temperature fag bearing to ensure that all excess grease in the bearing is discharged.
2) Clean and replace pipe fittings. Pump a small amount of grease into the bearing to avoid breaking the grease seal.
3) Remove the fittings and allow the equipment to run at its operating temperature for several minutes to drain excess grease. If no grease is discharged, the bearing is likely to be very dry, and steps 2 and 3 need to be repeated until the excess grease is discharged.
4) Replace grease fittings.
1) Clean the pipe fittings and pump the grease into the bearings until the grease flows out of the pressure reducing pipe fittings.
2) If the grease is still a style = “white-space: normal” href=“ http://www.bearing123.com/ “> If INA Bearing flows out of the pressure reducing pipe fitting, the pressure reducing groove may be blocked. Remove the pressure reducing pipe fitting and clean the pressure reducing groove or replace it with a new pipe fitting. After the pipe fitting is cleaned or replaced, repeat step 1.
3) Operate the equipment at operating temperature and check whether there is excess grease flowing out at the pressure reducing pipe fittings.
Ensure that all excess grease and dust from the bearing and its surroundings are cleaned. Excess grease and dust on the outer surface can keep warm and prevent heat dissipation. In addition, excess grease on the external surface and ground of the equipment will bring safety hazards to people, so these steps should be strictly followed.
In case of hard soap precipitation, flush the bearing housing with hot oil in the oil gun. Make sure to replace all the old oil in the bearing with new grease before running NSK bearing.
It is unrealistic to wash out all the grease in large bearings, such as paper machine bearings. Please determine the amount of bearing grease according to the manufacturer’s instructions.
Please pay attention to the “danger signals” of abnormal bearing operation, such as abnormal noise, vibration and temperature. Making sure to pay more attention to these signs is very helpful to maintain normal operation. Working condition monitoring instruments can be used to assist in detecting poor operating conditions of local bearings.