tailieunhanh - Rolling Bearing Damage 2009 Part 9

Tham khảo tài liệu 'rolling bearing damage 2009 part 9', 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 Cage damage Wear due to roller skewing Symptoms Roller skewing results when roller bearings carry low loads or badly tilt or when tapered roller bearings are not sufficiently adjusted. If the skewing forces cannot be accommodated by the lips wear areas which are diagonally opposite one another develop due to the unper-missibly high load in the cage pockets. This can lead to fractures between crosspiece and side edge in the advanced stage of damage fig. 90. Causes Unpermissible tilting of bearings partly due to misalignment Faulty adjustment of clearance in the bearings Remedial measures Adjust bearings correctly Use self-aligning bearings avoid misalignment 90 Diagonal wear in cage pockets of roller bearings Wear in ball bearing cages due to tilting Symptoms Intense wear at the webs between the cage pockets deformation or fracture may occur fig. 91 tracks compare with fig. 38 . Causes Excess tilting of bearing rings to one another . ball bearings with combined load. Varying circumferential velocity of balls as a result. Stress in cage area high particularly with poor lubrication Remedial measures Avoid tilting as much as possible Apply eventually self-aligning bearings or bearings with polyamide cages Special design long hole pockets 91 Bearing rings tilting towards one another led to high constraining forces between balls and cage which in turn led to web fracture. 55 I FAG Evaluation of running features and damage to dismounted bearings Cage damage Fracture of cage connections Symptoms Loosening of riveted joints rivet fracture fig. 92 Breaking off of cage prongs Causes Vibrations or shocks which superimpose the normal cage stress . vibrating units or vehicles Tilting in the case of deep groove ball bearings Remedial measures Use of solid cage rather than pressed cage Use of window-type cage particularly when stress is great 92 Fractured cage-rivet connections may result from