The bearings, lubrication is important questions about its performance. Lubricant or lubricating mode is suitable or not will greatly affect the bearing life.
The role of lubrication: 1) the bearing lubrication, reducing the channel surface and the steel ball, ball rotary friction and sliding friction, the sliding friction retainer and the channel guide plane 2) take bearing internal friction heat and the other from an external heat, prevent deterioration of the heating of the bearing and lubricant 3) of the rolling bearing contact surfaces often forming oil film appropriate, relieve the impact load concentrated stress and fatigue life of bearing steel ball, 4) to prevent channel, keep the intrusive for corrosion and garbage, foreign body, moisture, rust and dust bearing.
Lubrication of grease lubrication and oil lubrication, the general comparison is shown as follows:
Grease oil project The sealing device has the advantages of simple structure is more complex, need to pay attention to maintenance Good lubricating performance is very good Speed low-speed and medium speed can also be used for high speed Large and small torque Lubricant replacement is troublesome simple Lubricant life shorter length The cooling effect is not good (circular) Filter the impurities difficult easy Lubricant leakage oil spill pollution less suitable for no leakage places Zhi Runhua Lubricating grease fill can be achieved after a grease long time does not need to be added, and the sealing device structure is relatively simple, so widely used. Lubricating grease in advance of the seal seal type bearing grease filling, and the filling amount of grease the inside of the shell, grease filling for every once in a while to supplement or replace.
In addition, the multiple bearings require lubrication of machinery, also use the pipe connected to the centralized supply in the lubrication of grease.
1) filling amount of lubricating grease Grease filling shell structure and volume with the shell and different, filled to volume of 1/3 should be 1/2.
The filling volume is excessive, grease for stirring heating deterioration, aging and softening, should be noted.
But for low speed bearings, to prevent foreign invasion, sometimes filling to the volume of the 2/3－1.
2) and replace and replenish the lubricating grease Add grease and replacement has a close relationship with lubrication, either way, must use grease clean, and pay attention to prevent the intrusion of external foreign body. Grease replenishment should be day for the same brand of lubricating grease. Add grease, particularly important is should ensure that the new grease into the bearing internal indeed.
Oil lubrication High temperature lubricating oil is suitable for high speed bearings and is resistant to certain degree, but also to reduce the vibration and reduce noise effectively, mostly for grease lubrication is not applicable.
Oil lubrication is roughly divided into: (1) the oil bath lubrication oil drip lubrication (2) (3) the splash lubrication (4) the lubrication cycle (5) (6) injection lubricating oil mist lubrication (7) the oil air lubrication Standard lubricant The oil is composed of base oil, thickening agent, additives. Semi solid lubricant, according to its portfolio to select appropriate to use oil. (1) base oil Base oil is generally most of the use of mineral oil, but in order to improve the heat resistance, low temperature fluidity, therefore also use silicone oil, synthetic oil. (2) the tackifier Tackifier with various composite agent, is to control the mechanical stability, water resistance, temperature range characteristics.
(3) additive According to the purpose of use, plus a variety of additives.
· extreme pressure additives, the impact load and heavy load up. · oxidation additive to prevent the long time oxidation and deterioration of no supplement.
· antirust additive to prevent bearing and its surrounding corrosion. (4) viscosity Said grease hardness levels, is 5 seconds set metal cone weight into the fat depth (0.1mm) physical quantity, the bigger the soft value. (5) the drop point A flow of oil after heating, starting from the specified holes drip drop point temperature is, the higher value of the use of high temperature. (6) mixed heterogeneous oil Tackifier and additive mixture, changes in the nature of oil, so the principle of various oil is best to avoid mixing. (7) into the amount of fat (8) the grease life (9) additional clearance grease Even if the use of high quality oil, but because of the long-term use, the surrounding environment and so on, the degradation properties of oils and fats, low lubricating performance, so as to timely supplement and replace oil. General 50 ℃ operating temperature 1 years 1 times, more than 100 ℃ even with good heat resistance of the best 1 years of exchange of 2 ~ 3 times.
Lubricant standard non specified as follows: the basic types of working temperature scope of application of oil grade lubricating grease Chevron Chevron SRI-2 mineral grease -30 ~ 180 high temperature resistant, water resistant Shell Shell Alvania 2 mineral grease -35 ~ 120 long life, extensive use Shell Doliun R Shell stone grease -40 - 150 corrosion resistance, water resistance The synergy Kyodo Yoshi SRL synthetic lipid -40 ~ 150 low noise, low torque Mobil HP Mobil lithium chromium synthetic lipid -30 ~ 110 vibration resistance, corrosion resistance DuPont Dupont Krytox240AC fluorinated resin -35 ~ 290 high temperature resistant, good property Esso Exxon Beacon 325 synthetic lipid -55 ~ 120 grease