Slewing bearings under load, have a week to turn in signs of flaking, outer ring only on short axis symmetric location of signs of falling off. This is the main reason for early failure of the bearing, the bearing failure tests showed that roundness of the bearing outer diameter process control has been removed from the original 0.8 μ m to 27 μ m. This value is much larger than the radial clearance values. Therefore, it is certain that the bearing is severely deformed and-clearance work, easy to face early proliferation of abnormal wear and spalling. 'S response is to improve precision or shell holes as far as possible in the shell holes in two separated structures.
1. Raceways inclined to peel:
Is inclined to peel on the face ring with the turntable bearing, that bearing is working in a tilted, when when the slope angle reaches or exceeds the critical, early rapid wear of abnormal formation and spalling. Main reason is because the poor, shaft deflection, the precision axle journal and the shell holes and low, taking measures to ensure the quality of bearing installation and improve shoulder, shoulder axial runout accuracy of hole.
2. Ring fracture:
Fracture failure of races are usually less seen, is often caused by sudden overloads. Causation is complex, such as slewing bearing raw material defects (bubbles, shrinkage), forging defect (fire), heat treatment defects (overheating), processing defects (partial burns or micro-cracks on the surface), host a defect (poor poor installation, lubrication, instantaneous overload), once with load shock load or high vibration is likely to make the ring fracture. Take countermeasures in order to avoid overload impact loads, select the appropriate interference, improve precision, use conditions and strengthened bearings of quality control in the manufacturing process.
3. Channel Flake is symmetric in the circumference location:
Symmetric circle around the rim, Peel Peel, flake patrons ring a week to the symmetric location (that is, the short axis of the ellipse), the cause is mainly due to the shell hole oval or in two separate shell structure, especially in the camshaft bearings for motorcycle. When slewing bearing pressed into the shell of the large oval hole or in two separate enclosures when you tighten, make the bearing outer ring oval, short axis clearance significantly lower or even negative clearance.
Due to the temperature, lubrication, speed, load, environmental impact, value only indicates the approximate temperature range in the table. Role of bearing lubrication lubricate the friction, abrasion, and fatigue life of rolling bearings have important implications, such as temperature, vibration, without proper lubrication, the bearings will not work. Causes analysis of bearing damage shows that 40% per cent of the damage are associated with poor lubrication of the bearings. Therefore, good lubrication of the bearing is the effective measure to reduce bearing friction and wear. In addition, the bearings lubricated with heat, rust-proof, sealed, multiple roles, such as easing the impact, effect of bearing lubrication can be briefly described as follows:
A. in two roll surfaces in contact with each other or the sliding surfaces form a thin oil film between two surfaces separated by reducing friction and wear of contact surfaces.
B. oil lubrication, especially with circulating oil lubrication, oil mist lubrication and oil lubrication, the lubricating oil can take most of the friction inside the bearing heat, efficient thermal dissipation role to play.
C. grease lubrication, prevents external dust and other foreign matter entering the bearing, played a close role.
D. role of lubricant to prevent corrosion of metals.
E. extension of fatigue life of bearings.


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