Grinding is the core means of the bearing manufacturing industry. It occupies the main production time and cost. The quality of grinding and productivity are related to the success of bearing companies. Floating gripper type centerless grinding (commonly referred to as 'Microcentric') is the most common technique for producing bearing rings. It is so common because of three main advantages:
– Very fast workpiece handling.
- The bearing ring is ground without stress. After processing, it has almost no deformation.
– It is entirely possible to achieve better accuracy/roundness beyond the spindle of the machine itself. At the same time, Microcentric has several important fundamental weaknesses:
1. The geometric and dynamic stability during grinding is low. The roundness of the final bearing ring is very sensitive to the optimum position of the "floating clamp arm", the initial roundness of the ring, the feed rate and other conditions, and so on. Due to the above factors, each harmonic may be generated again and more and more.
2. A lot of time is spent on modifying the settings of the machine, and only trained people can do the job. The operator must find the optimum position of the “floating clamp arm” (the angle between the α and β of the floating clamp arm and the grinding point). The optimal α-β angle is the balance between achieving the best accuracy and highest efficiency. It usually takes multiple iterations. In addition, this technology requires regular accuracy monitoring and regular machine adjustments.
3. The rigidity of the workpiece processing system is insufficient - thin-walled bearings
- it has become a huge problem in the processing of thin-walled bearings.
Overcoming the above technical deficiencies is crucial. At present, the global bearing market is highly competitive. The market demands higher precision and more customer-specific bearings
, but the price is moderate. Many bearings are produced in small batches. Under such conditions, to make money, technical flexibility is the key. Unskilled industrial labor that lacks technology has hit all economies. Long and complicated machine setups turn into a real problem. In addition, because of the new steel material application and advanced design, modern bearings become lighter and lighter, which means that the bearing ring becomes thinner and thinner, and the rigidity of the bearing workpiece system is getting lower and lower.