A simple method to distinguish true and false SKF bearings
1. First look at the outer packing box of the bearing. The general packing box is white, with a blue background and a red strip under it. However, the products in the past two years have flower boxes with several Skf Bearings trademarks.
2. Look at the production date of the bearing. If Skf Bearings the packing box of the bearing is opened from the side, the box has the production date and date code.
3. The packing box of Skf Bearings produced after 2000 has bar code.
4. Look at the bearing model. The bearing model has suffix letters a, B, C, D, e, etc. these letters represent different production years respectively. Skf Bearings See the attached table for specific information.
5. Pay attention to the SKF font on the trademark. S is narrow at the top and wide at the bottom. Skf Bearings There are pits on the left vertical drawing of K and F.
6. Look at the steel seal. Skf Bearings The letters indicating the model and origin on SKF Bearing include pickling and laser processing. It is smooth when touched by hand, and the font of false bearing is generally engraved.
7. Look at the origin. Skf Bearings The origin of ball bearing: Malaysia, Italy, France The United States (bearings made in the United States are generally only used in the United States); origin of short cylindrical bearings: Germany; origin of angular contact bearings: Austria; origin of spherical roller bearings: Malaysia (generally small 2315, 2316 and 2318), Sweden (large model), Germany (large model); origin of needle roller bearings: Germany.
8. After unpacking the bearing, the large bearing is generally sealed plastic bag and the small bearing is plastic packaging paper. Skf Bearings There is a layer of grease on the bearing. The appearance of the bearing is bright without rust and pitting.
We all know that many imported bearings will fail. Skf Bearings Many users of imported bearings have this situation. Why? The failure of imported bearings has become a new problem for us. We need to find all ways to solve this problem. What is the solution? This problem is so difficult to solve.
Of course, it is difficult to solve. Imported bearings are easy to fail This is a common problem when we use imported bearings After the bearing runs for a period of time, it is necessary to check whether there are problems, especially whether it fails. Skf Bearings Today I will tell you the failure classification of imported bearings.
Contact fatigue failure refers to the failure of bearing working surface under the action of alternating stress. Contact fatigue spalling occurs on the working surface of the bearing and is often accompanied by fatigue cracks.
It first occurs from the Skf Bearings 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, which 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.
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 Skf Bearings the surfaces. Continuous wear will cause gradual damage to bearing parts, and eventually lead to loss of bearing dimensional accuracy and other related problems.
Wear may affect the change of shape, the increase of fit clearance and the change of working surface morphology, may affect Skf Bearings the lubricant or make it polluted to a certain extent, resulting in the complete loss of lubrication function, resulting in the loss of rotation accuracy and even normal operation of the bearing.
Wear failure is one of the common failure modes of various bearings. According to the wear form, Skf Bearings it can be divided into common abrasive wear and adhesive wear. 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 imported bearings, which often causes furrow like scratches on the working surfaces of bearings.
Hard particles or foreign matters may come from the inside of the host machine or from other Skf Bearings adjacent parts of the host system and are sent into the bearing by the lubricating medium. 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. In serious cases, the surface metal may be locally melted, and the force on the contact surface will tear the Skf Bearings local friction welding point from the substrate and increase the plastic deformation.
This cyclic process of adhesion tear adhesion constitutes adhesive wear. Generally speaking, slight adhesive wear is called scratch and severe adhesive wear is called bite.
The main reasons for the fracture failure of imported bearings are defects and overload. When the external load exceeds the material strength limit and causes the Skf Bearings part to break, it is called overload fracture. Overload is mainly caused by sudden failure or improper installation of the host.
Defects such as microcracks, shrinkage cavities, bubbles, large foreign objects, overheated tissue and local burns of bearing parts will also cause fracture at the defect during impact overload or severe vibration, which is called defect fracture.
It should be pointed out that in the manufacturing process of bearings, the presence of the above defects can be correctly analyzed by instruments in the factory re inspection of Skf Bearings raw materials, quality control of forging and heat treatment, and processing process control, and the control must still be strengthened in the future. But generally speaking, most of the bearing fracture failures are overload failures.
During the operation of imported bearings, due to the influence of external or internal factors, the original matching clearance is changed, the accuracy is Skf Bearings reduced, and even “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 Skf Bearings the main causes of clearance change failure.