Lubrication has an important influence on the fatigue life, Scheme And friction, wear, temperature rise and vibration of NSK Bearings, especially rolling bearings. Without normal lubrication,
the bearing cannot work. The causes of NSK bearing damage show that about 40% of bearing damage is related to poor lubrication. Therefore, good Scheme And lubrication of NSK bearing is an effective measure to reduce bearing friction and wear.
In addition, the lubrication of NSK Bearings has many functions, such as heat dissipation, rust prevention, sealing, mitigation of impact and so on.
The role of NSK bearing lubrication can be briefly Scheme And described as follows
a. An oil film is formed between the two rolling surfaces or sliding surfaces in contact with each other to separate the two surfaces and reduce the friction and wear of the contact surface.
b. When oil lubrication is used, especially when circulating oil Scheme And lubrication, oil mist lubrication and oil injection lubrication are used, the lubricating oil can take away most of the friction heat inside the bearing and play an effective role in heat dissipation.
c. When grease lubrication is used, it can prevent external dust and other foreign matters from Scheme And entering the bearing and play a sealing role.
d. Lubricants can prevent metal corrosion.
e. Prolong the fatigue life of NSK bearing.
1、 Requirements for installation surface and installation site
If there are iron filings, burrs, dust and other foreign matters in the bearing, the bearing will produce noise and vibration during operation, and even damage the raceway and rolling element. Scheme And Therefore, before installing the bearing, you must ensure that the installation surface and installation environment are clean.
The bearing surface is coated with antirust oil. You must carefully clean it with clean gasoline or Scheme And kerosene, and then apply clean, high-quality or high-speed and high-temperature lubricating grease
before installation and use. Cleanliness has a great impact on NSK bearing life and vibration noise. However, we would like to remind you that there is no need to clean and refuel the fully enclosed bearing.
3、 Selection of lubricating grease
Lubrication has a very important impact on the operation and Scheme And service life of NSK Bearings. Here we briefly introduce the general principles of selecting grease. Lubricating grease is made of base oil, thickener and additives. The performance of different kinds and different brands of lubricating grease of the same kind varies greatly,
and the allowable rotation limit is different. Be sure to pay attention to it when selecting. The performance of lubricating grease is mainly determined by the base oil. Generally, the base oil with low viscosity is suitable for low temperature and high speed, and the base oil with high viscosity is suitable for high temperature and high load.
The water resistance of thickener determines the water resistance of grease. In principle, greases of different brands cannot be mixed, and even greases with the same thickener will have bad effects on each other due to different additives.
4、 Addition of grease
When lubricating bearings, the more grease the better, which is a common misconception. Too Scheme And much grease in NSK bearing and bearing chamber will cause excessive mixing of grease, resulting in extremely high temperature.
The amount of lubricant filled in the bearing should be 1 / 2 ~ 1 / 3 of the internal space of the bearing, and should be reduced to 1 / 3 at high speed.
5、 Installation and disassembly of bearing
During installation, do not directly hammer the end face and non Scheme And stressed surface of NSK bearing. Use pressure block, sleeve or other installation tools to make the bearing bear uniform force. Do not drive the installation through the rolling element. If the mounting surface is coated with lubricating oil, the installation will be more smooth.
If the fit interference is large, the bearing shall be put into mineral oil and heated to 80 ~ 90 ℃ before installation as soon as possible. The oil temperature shall be strictly controlled not to exceed 100 ℃ to prevent tempering effect, hardness reduction and size recovery. In case of difficulty in disassembly,
it is recommended that you use the disassembly tool to pull outward and carefully pour hot oil on the inner ring. The heat will expand the bearing inner ring and make it easier to fall off.
6、 Selection of bearing radial clearance
Not all NSK Bearings require small working clearance. You must choose the appropriate clearance according to the conditions. In national standard 4604-93, the radial clearance of rolling bearing is divided into five groups – group 2, group 0, group 3,
group 4 and group 5. The clearance value increases from small to large, of which group 0 is the standard clearance. The basic radial clearance group is suitable for general operating conditions, conventional temperature and common interference fit;
Large radial clearance should be selected for bearings working under special conditions such as high temperature, high speed, low noise and low friction; Small radial clearance should be selected for precision spindle and NSK bearing for machine tool spindle; For roller bearings, a small amount of working clearance can be maintained.
In addition, there is no clearance for separate bearings; After installation, the working clearance of the bearing after installation is smaller than the original clearance before installation, because the bearing has to bear certain load rotation, as well as the elastic deformation caused by bearing fit and load.