1、Processing sequence

(1) Cutting of thin-walled bearings. When the surface of the grinding stone comes into contact with the rough raceway surface and the protrusions on both surfaces are in contact, due to the small contact area, the force per unit area is relatively large. Under the action of a certain pressure, the grinding stone is first subjected to the "reverse cutting" effect of the bearing workpiece, causing some of the abrasive particles on the surface of the grinding stone to fall off and crack, and gradually exposing some new sharp abrasive particles and cutting edges. At the same time, the protrusions on the surface of the bearing workpiece are subjected to rapid cutting, and through the cutting and reverse cutting effects, the protrusions and the grinding deterioration layer on the surface of the thin-walled bearing workpiece are removed. This stage is called the cutting stage, and during this stage, most of the metal excess is removed. 

(2) Semi-cutting of the bearing. As the processing continues, the surface of the thin-walled bearing workpiece gradually becomes smooth. At this point, the contact area between the grinding stone and the workpiece surface increases, and the pressure per unit area begins to decrease. The cutting depth gradually decreases, and the cutting ability also weakens simultaneously. Moreover, the pores on the surface of the grinding stone are blocked, and the grinding stone is in a semi-cutting state. During the semi-cutting stage, the cutting marks on the surface of the bearing workpiece become shallower, and a darker luster appears. 

(3) Finishing Stage. This stage is a step in the ultra-finishing process of the bearing. As the surface of the workpiece is gradually smoothed, the contact area between the grinding stone and the workpiece surface increases further. Moreover, the grinding stone and the thin-walled bearing workpiece surface are gradually isolated by an oil film, resulting in a very small pressure per unit area and a reduced cutting effect. The cutting stops automatically afterwards. During the finishing stage, there are no cutting marks on the workpiece surface, and the bearing presents a shiny finished appearance.

2、Processing difficulties

(1) In the forging process, for thin-walled bearing rings with large dimensions and a small aspect ratio, the production is carried out using the method of two-piece or multiple-piece forging. After the rough grinding process, the rings are separated using wire cutting to reduce the processing difficulty in the forging process, minimize the deformation of the rings and the end face processing allowance, save raw materials, and improve production efficiency. 

(2) In the machining process of the vehicle, the main factors affecting the machining accuracy include clamping, excessive cutting force, unreasonable fixture design, deformation caused by cutting heat, and vibration during the cutting process. To reduce the deformation resulting from excessive stress during the machining process, a steel soft chuck with a large contact area and not heat-treated is used to clamp the ring for rough machining. For example, a multi-point clamping chuck (twelve-point or twenty-four-point clamping) can be used; the clamping scheme can be changed (from radial clamping to end face pressing); the process parameters can be adjusted (high-speed cutting, small back-cutting depth, larger main rake angle of the tool, smaller tip arc radius, and reasonable selection of cutting fluid, etc.). After the rough machining, an additional tempering process is added to eliminate the stress. Then, the end face is ground, and the ring is further machined precisely. 

(3) During the heat treatment process, the internal structure of the sleeve undergoes a phase transformation, mainly from austenite to martensite. The density decreases and the volume expands, resulting in structural stress. Additionally, the sleeve rapidly quenches from the expanded state at high temperature (for thin-walled products, it is generally 830-845 ℃) and undergoes thermal stress. When these two types of internal stresses exceed the yield limit of the material, the material will undergo plastic deformation. Usually, the deformation is controlled by die quenching. When there are no conditions for die quenching and the external diameter deformation after quenching is too large and exceeds the process requirements for the sleeve, a comprehensive shaping is carried out first, followed by tempering to correct it and control it within the process requirements. 

(4) During the grinding process, the key lies in selecting the appropriate grinding equipment, processing methods, and grinding process parameters. For example, the method of using a reinforced ring is adopted, and the structure of "one followed by two" is employed for processing; the outer diameter surface is ground using the method of multiple fine adjustments of the machine tool; and tempering stabilization treatment is added during the process, ensuring that the grinding quality of the ring meets the process requirements.

3、Installation Instructions

1. The bearing environment meets the requirements. When installing and using the bearing, it is essential to ensure that the surrounding environment of the bearing is clean, tidy, and dry. Many tiny dust particles are invisible to the naked eye, but if they enter the bearing, they will increase the wear and noise of the bearing. 

2. Apply proper force during installation. When installing, be meticulous and careful. The thin-walled bearings have high precision themselves, and forceful pressing is not suitable for their installation. Directly using a hammer to strike the bearings is also not allowed, as it will affect the service life of the bearings. In more serious cases, it can even directly damage the bearings. Additionally, during installation, be sure to avoid using items such as cloth and short fibers, as these fibers are prone to leaving debris, which will cause unnecessary pressure on the bearing operation and seriously harm the service life of the thin-walled bearings. 3. Implement rust prevention measures. If installing bearings in summer, proper rust prevention work should be done. Because in summer, there is a lot of sweat on hands, directly handling them with hands may cause external rusting of the bearings, leading to faults in the thin-walled bearings. Rusting will also directly affect the service life of the thin-walled bearings. It is recommended to wear gloves or thoroughly wash off the sweat on your hands, and apply mineral oil before conducting the installation operation. Please provide the text that needs to be translated accurately and without