Transmission NTN bearing failure analysis - bearing on knowledge

NTN bearing faults on transmission phenomenon: sound transmission gear meshing, NTN bearing, sound operation, such as the noise is too big; Transmission from dry grinding impact such as abnormal sound. Reason: rolling NTN bearing oil deficiency ( Before the first axis NTN bearing) , loss to round steel ball mill, pitting, delaminating, scars, both inside and outside groove on the shaft or casing rotation, or NTN bearing gap is too big. Excluding method is: add oil, to replace the damaged NTN bearing; Gear machining precision or improper heat treatment technology of gear yawing or tooth shape change. Elimination method is: the replacement of damaged gear; The backlash is too large or spline fit clearance is too large. Elimination method is: the replacement of damaged synchronizer hub and shaft; Repair of tooth surface without burr, bumps, etc for finishing. Elimination method is: repair tooth surface; Tooth surface spalling, delaminating, defects, wear gear does not change in pairs or even in a fix. Elimination method is: the replacement of damaged gear; The first axis, the second shaft bending deformation. Elimination method is: the replacement of the deformation of shaft; NTN bearing shell hole boring set set of repair, make the two hole center distance change or make two axis is not parallel. Elimination method is: the replacement of damaged casing; After repair of the fork camber is wrong or fork wear after the single side welding is too thick, the related gear position is not allowed. Elimination method is: change the fork; The second shaft fastening nut loose or other each shaft axial positioning phrase. Elimination method is: reassemble; Self-locking device groove, steel ball wear or even self-locking spring fatigue, broken, cause shift offside. Excluding method is: change the fork shaft, ball or spring; Individual tooth fracture. Elimination method is: the replacement of damaged gear; Gear oil shortage, metamorphism and specifications do not conform to the requirements or impurities in the oil. Elimination method is: add or replace conform to the requirements of the oil. NTN bearing load capacity than the same volume of sliding NTN bearing much smaller, therefore, NTN bearing radial size large. So, under heavy load situations and demands radial size, structure compact occasions (such as internal combustion engine crankshaft NTN bearing) , use slide more NTN bearing; NTN bearing particularly sensitive to scrap metal and other foreign bodies, NTN bearing inner once in foreign body, can produce bigger vibration and noise in an intermittent, also can cause early damage. In addition, NTN bearing due to metal inclusions are prone to the possibility of the early damage. Even if they don't happen early damage, NTN bearing's life also to have certain limit. All in all, NTN bearing of life is the shorter of the sliding NTN bearing. However, NTN bearing compared with sliding NTN bearing, each have advantages and disadvantages, each has certain applicable occasions, therefore, they cannot fully replace each other, but, because of the prominent advantages of NTN bearing, at present, NTN bearing has developed into the main bearing type mechanical, more and more widely applied.