First Cross Roller Bearing Introduction
In the existing industrial production environment, CNC vertical vehicles are widely used in industrial production. However, most of the existing CNC vertical lathe spindle structure applications still use the traditional structure, that is, the combination of double row cylindrical roller bearings and plane bearings. Compared with traditional structural applications, cross-roller bearings have many advantages, which not only meet the requirements of traditional spindle structure applications, but also play a more effective role in optimizing the spindle structure of CNC vertical lathes.
YRT crossed roller bearings are two rows of cylindrical rollers that are vertically aligned with each other through a nylon spacer on a 90-degree V-shaped raceway. Therefore, the crossed roller bearing can withstand multiple directions such as radial load, axial load and moment load. The load. The size of the inner and outer rings is miniaturized, the extremely thin form is a small size close to the limit, and the high rigidity is such that the cross roller bearing structure is compact, the volume is not too much, and the cost for the design workbench is also reduced. . In the cross-roller bearing, since the roller in the bearing is in line contact with the raceway, the load of the entire crossed roller bearing is larger than that of the conventional bearing structure, and the radial load and the axial load are still the same. Crossed roller bearings can withstand. Because of its special roller arrangement, the probability of cross-roller bearing deformation due to heavy load is greatly reduced. The radial external load of the cross roller increases, and the inner and outer rings of the roller also increase the load of the roller, but the area of contact between the roller and the raceway is reduced, that is, the roller becomes uneven. The size of the inner and outer rings of the cross roller is continuously reduced. The current cross roller scale is an ultra-thin small roller, but its rigidity is still high, so it appears in a large number of mechanical uses.
As the load on the bearing increases, not only does the contact load of the *large loaded roller increase, but the unevenness of the load applied to the roller also increases. Therefore, the influence of external load on the roller contact load distribution should be considered in the process of designing the bearing. As the bearing clearance decreases, the load on the roller increases. When the negative clearance value of the bearing is large, the contact area between the raceway and the roller is obviously reduced, and the load distribution is not uniform. The influence of the bearing clearance on the bearing load distribution cannot be ignored.
Second, the application of traditional bearing structure in CNC vertical lathe
Before the advent of crossed roller bearings, lathe spindles are generally traditional bearing structures. The traditional bearing structure relies mainly on thrust ball bearings to support the work. Thrust ball bearings can withstand certain axial forces, so the bearings are mainly used for It bears the weight of the workpiece; cylindrical roller bearings are mainly used for radial positioning and external radial forces. This type of design is widely used. And the cost is relatively low. Since the thrust ball is a point contact bearing, its axial bearing capacity is relatively low, and it is mainly used in small or medium-sized machine tool rotary table. In addition, the lubrication of the thrust ball is also difficult. The main working principle of the thrust ball bearing is that the main motor transmits the power to the large ring gear under the turntable through a series of transmissions from the gear box. The large ring gear passes through the thrust ball bearing and the angular contact ball bearing outer ring to drive the table support. And the rotary table that is combined with it rotates, thereby realizing the rotary motion of the lathe work table.
Third，Application of Crossed Roller Bearings on CNC Vertical Lathe
The advantages of cross roller bearing applications in CNC vertical lathes. The application of cross-rollers in the spindle of CNC vertical lathes has gradually gained recognition. The roller has a relatively small cross-sectional area in its special arrangement, which saves raw materials and reduces production costs in production and processing. It saves time and labor when driving the spindle, and the working efficiency and working accuracy of the entire CNC vertical lathe are greatly improved. Since the main shaft of the lathe is a crossed roller bearing, the time for forming the lathe is reduced, and the center of the spindle of the CNC vertical lathe is also reduced, but its performance is greatly improved. In addition, because the rollers are arranged in a cross arrangement, the effective distance between the rollers is increased, and the degree of rotation and stability are improved. When the roller rolls to rotate the bearing, the rollers only roll relative to each other, and no slip occurs. Phenomenon, so the consumption of the entire CNC vertical lathe spindle is greatly reduced, reducing fuel consumption, relatively more environmentally friendly, reducing noise and reducing the use of raw materials.
