Causes of unexplained failure of IKo rotary table bearing during operation

1. Contact fatigue failure

Contact fatigue failure refers to the failure of IKO bearing working surface caused by alternating stress. Contact fatigue spalling occurs on the working surface of rotary table bearing, which is often accompanied by fatigue cracks. It first occurs from the large alternating shear stress below the contact surface, and then extends to the surface to form different spalling shapes, such as pitting or pitting spalling, and spalling into small flakes is called shallow spalling. Due to the gradual expansion of the spalling surface, it often expands to the deep layer, forming deep spalling. Deep spalling is the fatigue source of contact fatigue failure.

2. Wear failure

• Wear failure refers to the failure caused by the continuous wear of the metal on the working surface caused by the relative sliding friction between the surfaces. Continuous wear will gradually damage the rotary table bearing parts, and eventually lead to the loss of dimensional accuracy of IKO bearing and other related problems. Causes of unexplained failure of Ko rotary table bearing during operation
• Wear may affect the change of shape, the increase of fit clearance and the change of working surface morphology, may affect the lubricant or make it polluted to a certain extent, resulting in the complete loss of lubrication function, so that the bearing loses the rotation accuracy and even cannot operate normally. Wear failure is one of the common failure modes of various bearings. According to the wear form, it can be divided into common abrasive wear and adhesive wear.Causes of unexplained failure of Ko rotary table bearing during operation
• Abrasive wear refers to the wear caused by the relative movement of the contact surface due to the extrusion of foreign hard particles or hard foreign matters or wear debris on the metal surface between the working surfaces of IKO bearings, which often causes furrow like scratches on the working surfaces of imported bearings. Hard particles or foreign matters may come from the inside of the host machine or from other adjacent parts of the host system, and are sent into the bearing of the rotary table by the lubricating medium. Causes of unexplained failure of Ko rotary table bearing during operation
• Adhesive wear refers to the uneven stress on the friction surface due to the micro bulge or foreign matter on the friction surface. When the lubrication conditions are seriously deteriorated, the local deformation and friction micro welding of the friction surface are easy to be caused due to the heat generated by local friction.Causes of unexplained failure of Ko rotary table bearing during operation
•  In serious cases, the surface metal may be locally melted, and the force on the contact surface will tear the local friction welding point from the substrate and increase the plastic deformation. This cycle of adhesion tear adhesion constitutes adhesive wear. Generally speaking, slight adhesive wear is called scratch and severe adhesive wear is called bite.Causes of unexplained failure of Ko rotary table bearing during operation

3. Fracture failure

• The main causes of bearing fracture failure are defect and overload. When the external load exceeds the material strength limit and causes the part to break, it is called overload fracture. The main cause of overload is the sudden failure or improper installation of the host. The defects of IKO bearing parts, such as microcracks, shrinkage cavities, bubbles, large foreign objects, overheated tissue and local burns, will also cause fracture at the defect during impact overload or violent vibration, which is called defect fracture. Causes of unexplained failure of Ko rotary table bearing during operation
• It should be pointed out that in the manufacturing process of rotary table bearing, the presence of the above defects can be correctly analyzed by instruments in the factory re inspection of raw materials, quality control of forging and heat treatment and processing process control, and the control must be strengthened in the future. However, generally speaking, the fracture failure of IKO bearing is mostly overload failure.Causes of unexplained failure of Ko rotary table bearing during operation

4. Clearance change failure

• During the operation of rotary table bearing, due to the influence of external or internal factors, the original matching clearance is changed, the accuracy is reduced, and even the “bite” is called clearance change failure. External factors such as excessive interference, improper installation, expansion caused by temperature rise, instantaneous overload, etc., and internal factors such as residual austenite and residual stress in an unstable state are the main reasons for the change and failure of clearance.Causes of unexplained failure of Ko rotary table bearing during operation