Disassembly should be considered in the original design of NTN bearing installation position – if the bearing is installed with interference fit, a disassembly groove should be set on the shaft or in the bearing seat hole to facilitate the disassembly of the ferrule. If the disassembled angular contact ball bearing needs to be reused:
1. Avoid hitting the bearing ring directly,
2. The disassembly force shall not be transmitted through the body,
3. Once the bearing is disassembled, it shall be cleaned carefully and “violent” flame shall not be used.
When disassembling the lower NTN bearing for maintenance, first record the appearance of the angular contact ball bearing, confirm the residual amount of lubricant, and wash the bearing after sampling the lubricant for inspection. As a cleaning agent, gasoline and kerosene are commonly used.
The cleaning of the disassembled bearing is divided into coarse Ntn Angular Contact Ball Bearing cleaning and fine cleaning. Put the metal mesh pad bottom in the container respectively, so that the angular contact ball bearing does not directly contact the dirt of the container.
During rough cleaning, if the bearing rotates with dirt, it will damage the Ntn Angular Contact Ball Bearing rolling surface of the bearing, which should be paid attention to. In the coarse cleaning oil, use a brush to remove the grease and adhesion. After it is roughly clean, turn to fine cleaning.
Fine cleaning is to carefully clean the NTN bearing while rotating in the cleaning oil. In addition, the cleaning oil should always be kept clean.
1. The assembly site shall be kept as clean as possible without dust.
2. Prevent the bearing from being contaminated with dust, pollutants and moisture – pollutants have Ntn Angular Contact Ball Bearing adverse effects on the operation and service life of the diagonal contact ball bearing.
3. Check the mating surface of bearing seat hole and shaft: Ntn Angular Contact Ball Bearing geometric and dimensional accuracy and cleanliness.
4. Apply a little oil or grease to the mating surface of bearing ring.
5. Ensure that the shaft and bearing seat hole have a 10-15 degree chamfer.
6. Do not over cool the bearing: the water generated by condensation Ntn Angular Contact Ball Bearing can lead to corrosion of the bearing and its mating surface.
7. After installation: fill NTN bearing with lubricant and check whether Ntn Angular Contact Ball Bearing the angular contact ball bearing configuration operates normally.
1. Fatigue spalling
The inner and outer raceways of the rolling bearing and the surface of the rolling body bear both load and relative rolling. Due to the action of Ntn Angular Contact Ball Bearing alternating load, cracks first form at a certain depth under the surface (shear stress),
and then extend to the contact surface, resulting in spalling pits on the surface, and then develop into large spalling. This phenomenon is fatigue spalling. Fatigue spalling will aggravate the impact load, vibration and noise during operation.
Due to the invasion of dust and foreign matters, the relative Ntn Angular Contact Ball Bearing movement of raceway and rolling body will cause surface wear, and poor lubrication will also aggravate wear. As a result of wear, the bearing clearance will increase, the surface roughness will increase,
the bearing operation accuracy will be reduced, so the motion accuracy of the machine will be reduced, and the vibration and noise will also increase. For precision mechanical bearings, it is often the amount of wear that limits the life of the bearing.
3. Plastic deformation
When the shaft bears excessive impact load or static load, or Ntn Angular Contact Ball Bearing additional load caused by thermal deformation, or foreign matters with high hardness invade, dents or scratches will be formed on the raceway surface.
This will make the bearing produce violent vibration and noise during operation. Moreover, once there is an indentation, the impact load caused by the indentation will further cause the spalling of the nearby surface.
Corrosion is one of the serious problems of rolling bearings. High precision bearings may lose accuracy due to surface corrosion and cannot continue to work. Direct invasion of water, acid and alkaline substances will cause bearing corrosion.
When the bearing stops working, the bearing temperature drops to the dew point, and the water in the air condenses into water droplets attached to the bearing surface, which will also cause corrosion. In addition, when there is current passing through the inside of the bearing,
the current may pass through the contact point between the raceway and the rolling body. The very thin oil film may cause electric spark and produce electric corrosion, forming washboard like unevenness on the surface.
Excessive load may cause fracture of bearing parts. Grinding, heat treatment and improper assembly will cause residual stress.
Excessive thermal stress during operation will also cause fracture of bearing parts. In addition, improper assembly method and process may also cause block falling at the retaining edge of bearing ring and the chamfer of roller.
When working under poor lubrication, high speed and heavy load, due to friction and heating, the bearing parts can reach a very high temperature in a very short time, resulting in surface burns and gluing. The so-called gluing refers to the phenomenon that the metal on the surface of one part adheres to the surface of another part.
7. The cage is damaged
Improper assembly or use may cause deformation of the cage, increase the friction between it and the rolling elements,
or even make some rolling elements stuck and unable to roll, and may also cause friction between the cage and the inner and outer rings. This damage will further aggravate vibration, noise and heating, resulting in bearing damage.