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With the rapid development of China’s machine tool industry, the demand for machine tool parts is becoming stronger and stronger, especially in the turntable bearing. Therefore, the selection of turntable bearing has become a problem that users pay more and more attention to. The rotary worktable commonly used in NC machine tools generally includes indexing worktable and NC rotary worktable. CNC rotary table can be used to realize circular feed movement. In addition, it can also complete indexing movement. The function of the indexing worktable is only to transpose and change the surface of the workpiece, which is used together with the automatic tool change device to realize the installation of the workpiece at one time, and can complete a variety of processes on several surfaces. Therefore, the work efficiency is greatly improved. The shape of NC turntable is not much different from that of indexing worktable, but it has a series of characteristics in structure.
Because NC turntable can realize feed movement, it has many similarities with the feed drive mechanism of NC machine tool in structure. The difference is that the driving mechanism realizes linear feed motion, while the NC turntable realizes circular feed motion.
It is widely used in various CNC milling machines, boring machines, various vertical turning and vertical milling machines. These machine tools not only require the rotary worktable to bear the weight of the workpiece well, but also need to ensure its rotation accuracy under the load.
As the core component of the turntable, the turntable bearing should not only have high bearing capacity, but also have high rotation accuracy, high anti overturning capacity and high speed capacity during the operation of the turntable. Therefore, the cross roller bearing with compact structure and small volume is generally selected.
It uses the optimized preload and has high stiffness, so the stiffness and accuracy of the turntable are also guaranteed. Thanks to the design of two rows of cross rollers, the effective span of the bearing can be significantly improved, so this kind of bearing has high overturning moment. In the cross roller bearing, it is divided into two types: one is cylindrical cross roller bearing, and the second is conical cross roller bearing.
Generally, the price of cylindrical cross roller bearing is lower than that of conical cross roller bearing, which is suitable for turntable applications with relatively low speed; The tapered cross roller bearing adopts the pure rolling design of tapered roller, which has the characteristics of high operation precision and strong speed capacity, and reduces the shaft length and processing cost.