The failure phenomenon of the NTN
bearing on the transmission: the noise of the meshing of the transmission gear, the sound of the operation of the NTN bearing, etc.; the transmission emits an abnormal sound such as a dry grinding impact.
the reason:
Rolling NTN bearing oil shortage (such as the first shaft front NTN bearing), the steel ball mill loss round, the raceway has pitting, delamination, scar, the inner and outer races rotate on the shaft or inside the casing, or the NTN bearing clearance is too large. The elimination method is: replenish the oil and replace the damaged NTN bearing;
Gear machining accuracy or improper heat treatment process causes gear deflection or tooth shape to change. The troubleshooting method is: replace the damaged gear;
The backlash is too large or the spline fit is too large. The troubleshooting method is: replace the damaged synchronizer hub and shaft;
The repaired tooth surface does not trim the burrs, bumps, etc. The elimination method is: repair the tooth surface;
The gears are not replaced in pairs in the flaking, delamination, defect, wear or even replacement repair. The troubleshooting method is: replace the damaged gear;
The first axis and the second axis are bent and deformed. The elimination method is: replacing the deformed shaft;
After repairing the casing NTN bearing hole, the center distance of the two holes is changed or the two axes are not parallel. The troubleshooting method is: replace the damaged casing;
After the repaired fork is not right or the fork is worn, the unilateral surfacing is too thick, resulting in the position of the relevant gear is not accurate. The troubleshooting method is: replace the fork;
The second shaft fastening nut is loose or the other shafts are axially misaligned. The elimination method is: reassembly;
The self-locking device groove, the steel ball is worn out or the self-locking spring is fatigued or broken, resulting in off-position when the gear is engaged. The method of elimination is: replace the fork shaft, steel ball or spring;
Individual teeth are broken. The troubleshooting method is: replace the damaged gear;
Insufficient gear quality, deterioration, specifications do not meet the requirements or there are debris in the oil. The method of elimination is to replenish or replace the oil that meets the requirements.
1. NTN bearings are much less able to withstand loads than the same volume of sliding NTN bearings, so NTN bearings have large radial dimensions. Therefore, in the occasion of heavy load and the requirement of small radial size and compact structure requirements (such as internal combustion engine crankshaft NTN bearing), sliding NTN bearings are often used;
2. NTN bearings have large vibration and noise, especially in the later stage of use. Therefore, NTN bearings are difficult to handle in situations where high precision is required and vibration is not required. Generally, the effect of sliding NTN bearings is better.
3. NTN bearings are particularly sensitive to foreign objects such as metal chips. Once a foreign object enters the NTN bearing, intermittent vibration and noise will occur, which will cause early damage. In addition, NTN bearings are prone to early damage due to metal clip impurities. Even without early damage, the life of NTN bearings has a certain limit. In short, the life of NTN bearings is shorter than that of sliding NTN bearings.
However, compared with sliding NTN bearings, NTN
bearings have their own advantages and disadvantages, each occupying a certain applicable occasion. Therefore, the two cannot be completely replaced with each other. However, due to the outstanding advantages of NTN bearings, NTN bearings have been developed into mechanical ones. The main support type is more and more widely used.
