tailieunhanh - Rolling Bearing Damage 2009 Part 6

Tham khảo tài liệu 'rolling bearing damage 2009 part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Evaluation of running features and damage to dismounted bearings Pattern of rolling contact Corrosion damage Corrosion due to humidity rust Symptoms Brownish discolouration of the complete bearing surface usually unevenly distributed in the form of individual pits fig. 53. In many cases there are also spots of rust with pits at the rolling element pitch standstill corrosion . Capillary effect causes humidity to concentrate on the contact areas when standstill is for a long period fig. 54. This leads to wear at a later stage and premature fatigue originating at the rust pits. Causes Incorrect storage in warehouse relative air humidity 60 Extreme temperature variations condensation moisture Sealing failure accelerated by the abrasive action of dirt fig. 87 Unsuitable lubricant Remedial measures Suitable storage according to the specifications of rolling bearing manufacturer Improvement in seals additional shields perhaps Use lubricant with corrosion inhibitors Relubricate frequently in the case of grease lubrication particularly prior to standstill periods 53 Corrosion of the outer ring of a deep groove ball bearing the corrosion protection of which was destroyed by humidity 54 Corrosion pits in the raceway at rolling element pitch FAG I 34 Evaluation of running features and damage to dismounted bearings Pattern of rolling contact Corrosion due to aggressive media Symptoms Usually black etching pits fig. 55. Causes Incorrect storage in warehouse storage of aggressive chemicals in same area Sealing failure Unsuitable lubricant Remedial measures Storage in accordance with rolling bearing manufacturer s specifications Improvement in seals Use lubricant with corrosion inhibi- tors 55 Surface damage due to attack of aggressive media. The etching pits are usually black. 35 I FAG Evaluation of running features and damage to dismounted bearings Pattern of rolling contact False brinelling Symptoms Marks on the raceway surface at the rolling element pitch figs.