Review on Lubrication and Sealing Technology of High-Speed Motorized Spindle

Background: While the CNC (Computerised Numerical Control) machine spindle is driving the tool to cut the workpiece, impurities such as cutting fluid splash, metal chips, or metal dust tend to enter the internal system of the spindle. Optimization of the spindle sealing design can significantly improve the durability of the motorized spindle. A high-speed motorized spindle is the primary heat source of CNC machine tools. Under current conditions, a cooling and lubrication system is the main measure to control the heat of a high-speed motorized spindle. Objectives: This paper introduces the current research progress in bearing lubrication and new spindle sealing structures. Methods: The research on bearing lubrication is sorted by comparing the relevant literature on bearing lubrication; some sealing structures are introduced by giving examples of patents on motorized spindle seals. Results: This paper reviews the bearing lubrication research and spindle sealing structure and provides an outlook on the future development of bearing lubrication technology and spindle sealing structure. Conclusion: The High-speed motorized spindle is the primary heat source of CNC machine tools. Bearing lubrication can effectively control the motorized spindle heat; a motorized spindle sealing structure can prevent impurities from causing damage to the internal parts of the spindle and improve the service life of the motorized spindle.