The metal surface layer is plastically deformed by a mechanical method to form a hardened layer of high hardness and high strength. This surface strengthening method is called surface deformation strengthening, which is also called work hardening. Including shot peening, sand blasting, cold extrusion, rolling, cold rolling and impact, explosion shock strengthening. The characteristics of these methods are: increased dislocation density of the strengthening layer, refinement of the subgrain structure, thereby increasing the hardness and strength, and reducing the surface roughness value, which can significantly improve the surface fatigue strength of the part and reduce the sensitivity of the fatigue gap. The strengthening method is simple in process and remarkable in effect, and there is no obvious boundary between the hardened layer and the matrix, the structure is continuous, and it is not easy to fall off during use. Most of its methods have been applied in the bearing industry: the surface impact strengthening of rolling elements is the application of such methods, and precision rolling has become a new method of ferrule processing and strengthening.
The evaporability (degree) of the fag bearing grease indicates the degree of volatilization of the grease when the grease is used for a long period of time under high temperature conditions, and the smaller the evaporability, the better. The evaporability of the fat depends primarily on the nature of the lubricating oil and the fraction composition.
Oxidation stability refers to the ability of grease to resist heat and oxygen when used for long-term storage or long-term high temperature, maintaining its ability to not permanently change. Due to oxidation, the free base content is reduced or the free organic acid content is increased, the dropping point is lowered, the appearance color is deepened, the odor is exhibited, the consistency, the strength limit, the similar viscosity is decreased, the corrosive product is formed, and the structure of the grease is broken. Substance, causing the separation of soap oil. Therefore, in the long-term storage of grease, it should be stored in a dry and ventilated environment to prevent exposure to sunlight, and regular changes should be made to the changes of free alkali or free organic acid, corrosive and other items to ensure its quality and performance.
When inspecting a fag bearing, never expose the needle roller one-way bearing to a contaminant or moisture environment. If the work is interrupted, the machine should be covered with a piece of oil-paper plastic or similar material.
If the unshielded needle roller one-way bearing is cleaned without performing disassembly and may be inspected, it should be cleaned with a white spirit with a brush for application, and then dried or used with a lint-free cloth. Blow dry air (be careful not to let the fag bearing assembly start to rotate).
Do not clean the seal or dustproof fag bearing; just wipe the outer surface. If the needle roller bearing is damaged, it needs to be replaced.
