The raw materials manufactured by the ferrules are cylindrical rods or tube materials. Currently, according to different forming processes, the rolling bearing rings generally have the following manufacturing processes.
a. (bar stock) blanking - forging - annealing (or normalizing - turning (cold forming) - heat treatment quenching, tempering - grinding - part inspection - demagnetization, cleaning - submit assembly
b. (bar stock, tube stock) blanking - cold forming - heat treatment quenching, tempering - grinding - part inspection - demagnetization, cleaning - submit assembly
c. (Pipe) Cutting - Turning Molding - Heat Treatment Quenching, Tempering - Grinding - Parts Inspection - Demagnetization, Cleaning - Submit Assembly
d. (Bar) Blanking - Cold (Temperature) Extrusion - Turning - Heat Treatment Quenching, Tempering - Grinding - Parts Inspection - Demagnetization, Cleaning - Submit Assembly
Ferrule forming method: At present, in the processing of ferrules, there are mainly the following forming methods: forging, turning, cold rolling, and cold (temperature) extrusion. Among the above molding methods, forging processing is the most widely used, accounting for about 80% of the total production. For some small general-purpose products, rod (tube) materials can be directly turned and formed. Since the 1980s, some small and medium-sized enterprises in China have adopted cold heading and cold (temperature) extrusion molding in the production of small and medium-sized ferrules.
First, forging type
Through forging processing, metal internal defects can be eliminated, metal structure can be improved, metal flow lines can be reasonably distributed, and metal tightness can be improved. Forging-type machining technology is widely used in the bearing forming process, and it can process small products from inner diameter ~20mm to extra large products with outer diameter 5000mm. The common methods of forging are: hot forging, cold forging, warm forging, and hot forging in China.
Hot forging processing can be divided into: free forging processing technology, press forging technology, flat forging machine forging process and high speed upsetting forging process because of its different forming and processing equipment.
Second, cold heading molding
The cold rolling process is an advanced process method that can increase the material utilization rate, improve the compactness of the metal structure, and maintain the linearity of the metal flow. It is a no-chip processing method. Theoretically, cold heading products can be directly heat treated and ground without turning. At present, the cold rolling process is mainly applied to small and medium deep groove ball bearings. The main process is:
Forging Blanks (Ring)-Turning (except Ditch)-Rafters (Ditch and Chamfer) Full Diameter - Both ends of Soft Mill
When the cold rolling process and the forging process are used, the accuracy of the product is affected not only by the accuracy of the equipment but also by the precision of the forming mold.
Third, turning molding
In the bearing industry, the traditional turning molding technology is the use of special lathes, using a centralized process method to complete the molding process. However, this method is being eliminated due to the difficulty of adjusting the equipment used in this method, the low precision of the machine tool, and the low material utilization rate.
With the development of science and technology, CNC turning machine tools have rapidly developed and become increasingly sophisticated. At present, some products with complex shapes and high precision are increasingly adopting CNC turning molding technology.