Bearing rings precision cold rolling technology

Precision cold rolling technology is at room temperature, the ring rotational parts using extrusion and then give a cold plastic deformation method of forming the finished piece. Precision cold rolling allows workpiece size, shape, close to the theoretical maximum value of the finished piece. Its advantages are:
1 can significantly improve material utilization and processing efficiency. Compared with the traditional way of turning, precision cold rolling process allows the material saving rate increased by 10% to 15%, in order to achieve the radar bearing rings of cutting, reducing processing costs.
2. You can improve product quality. As a result of rolling manner, the internal parts of the metal flow lines continuous and complete, the metal grains more uniform and smaller, more dense tissue, so the strength of the parts can be improved. Meanwhile, due to the presence of surface residual stress finished parts, but also to the deformation after heat treatment of small parts.
3. You can save energy, improve the working environment. Compared to die, precision rolling equipment needed smaller tonnage, significantly reduces noise during processing, energy-saving effect. Compared with the turning blank, the noise, the dust is small.
When rolling a workpiece, the workpiece rotation drive roller wheel, mandrel under driven support wheel is fixedly connected with the feeding means pressing the workpiece, in order to achieve rolling of the workpiece. From the stress state of the workpiece, the forming conditions are satisfied: the horizontal direction of the work force required and the feed direction of the force exerted by the equilibrium, which is a necessary condition for a stable deformation; the force of the workpiece in the vertical direction must be greater than equal to deformation of the work arising from the introduction of force, which is to continue rolling conditions. These two forces are supported by wheels or rollers contact with the workpiece core arc normal force in the horizontal and vertical component. When the feed amount sufficient to ensure that the support wheels of plastic deformation throughout the thickness of the workpiece, deformation effectively. Moreover, depending on the amount of feed rollers wheel drive power, thrust thin bearings wheels, rolling wheels and a radius of curvature of the core roll. Feed rate determines the size of the core support wheels or rollers in contact with the workpiece length of the arc, corresponding to the deformation of the workpiece is produced by normal deformation force, the longer the contact arc, the greater the deformation force.
Due to rolling wheel, the radius of curvature of the inner and outer circle of the mandrel and the workpiece is different, every feed in and outside the workpiece deformation is not equal. The deformation of the workpiece will be greater than the outer deformation of the inner circle, as the rolling process is carried out, the difference between the amount of deformation of the inner and outer circle will decrease. Roundness of cylindrical stick used to control the workpiece. In the rolling process workpiece roundness always stick close to the cylindrical workpiece, with increasing diameter of the workpiece while back, and provides a constant full circle moment. Roundness of the stick but also to ensure the smooth adoption of the workpiece rolling process, effectively reducing the rolling vibration, thus extending the life of the mold and machine tool slewing bearings.
Currently, foreign fine rolling equipment mainly Germany BAD DUBEN of URAW series and Japanese KYOEI company CRF and TCR series. They represent the two techniques: BAD DUBEN with vertical layout, electro-hydraulic position servo control system to improve the accuracy of rolling, while KYOEI company uses a horizontal layout, rough rolling and the whole diameter of the workpiece to improve the combination of the workpiece dimensional accuracy.