As the core component of mechanical transmission, the accuracy and lifespan of bearings directly depend on the quality of external grinding. CNC external grinding machines have become key equipment in bearing manufacturing due to their precise control capabilities and process adaptability. Its technological application revolves around precision assurance, efficiency improvement, and quality stability, forming targeted solutions.
High precision grinding process is the core technology to ensure the performance of bearings. The perpendicularity between the outer circle and end face of the bearing ring, as well as the curvature radius of the raceway, need to be controlled at the micrometer level. The CNC cylindrical grinder achieves this requirement through the "one-time clamping multi surface grinding" technology: after the workpiece is positioned by a high-precision chuck or top pin, the grinding wheel frame and worktable move in coordination to synchronously complete the grinding of the outer circle, step surface, and chamfer, avoiding positioning errors caused by multiple clamping. For the grinding of bearing rollers, the forming grinding wheel technology is used, and the contour of the grinding wheel is precisely trimmed to match the shape of the roller busbar through a grinding wheel dresser, ensuring that the cylindricity error of the roller does not exceed 0.001mm. In addition, the centerless grinding technology is widely used in the mass production of small and medium-sized bearings, achieving self positioning grinding of the workpiece through the speed ratio between the guide wheel and the grinding wheel, greatly improving machining consistency.
Dynamic precision control technology is the key to addressing the characteristics of bearing materials. After quenching, bearing steel has high hardness and is prone to grinding stress. The grinder monitors the changes in grinding force in real-time through an adaptive grinding system and dynamically adjusts the feed rate. When an abnormal increase in grinding force is detected, the feed rate is automatically reduced to avoid workpiece burns or wheel cracking. The grinding wheel balancing technology is equally important. The built-in dynamic balancing device can compensate for the center of gravity deviation of the grinding wheel in real time, reduce vibration during high-speed rotation, and ensure that the surface roughness Ra value of the grinding wheel is stable below 0.4 μ m. For thin-walled bearing rings, low stress grinding technology is adopted to reduce the impact of thermal deformation on dimensional accuracy by optimizing the cooling path and grinding parameters.
Automation and intelligent technology have improved the efficiency and stability of bearing manufacturing. The process database integrated with the CNC system can store grinding parameters for different types of bearings, enabling one click calling and parameter optimization, and shortening the changeover time. The automatic loading and unloading mechanism is linked with the detection device to complete continuous grinding and online size detection of workpieces. The detection data is fed back to the grinder control system in real time, forming a closed-loop correction to ensure that the size dispersion of batch products is controlled within a very small range. Some grinders also have tool life management functions, which automatically trigger the dressing program by monitoring the wear of the grinding wheel to maintain stable grinding performance.
The technical application of CNC cylindrical grinding machine in bearing manufacturing reflects the unity of high precision, high efficiency and high stability, providing solid process guarantee for the performance improvement of bearing products, and is an indispensable technical support for modern bearing manufacturing industry.