It must be ensured that the rolling contact surface has been fully lubricated when the machine tool spindle bearing is installed. The dimensional accuracy of adjacent structures must be checked. If you want to obtain technical support during the initial installation, we recommend that you consult an expert in industrial services. Please refer to page 146, section Equipment and services for rolling bearing installation and maintenance. Single bearing solution In the single bearing solution, the compact design of the high-precision bearings YRTS and ZKLDF is different from the installation of the cross roller bearings given in the TPI catalog. The high-precision bearings are consistent with the sample TPI 120, and the high-precision bearings are installed in the sample TPI 103 (high-precision bearings with combined load). Crossed Roller Bearings Crossed Roller Bearings Z-556 have a specific axial preload set internally when they are delivered. For crossed roller bearings Z-549, the axial preload is set during installation. When installing the dual bearing solution, on the one hand, it is necessary to ensure that the thrust deep groove ball bearings and angular contact ball bearings run well in the radial direction. This can be achieved by centering equipment or aligning axial retaining rings. On the other hand, the axial preload must be set correctly by angular contact ball bearings. The three-bearing solution must ensure that the thrust deep groove ball bearing performs well in the radial direction relative to the radial cylindrical roller bearing. It can be achieved by centering equipment or centering operations. Radial cylindrical roller bearings must be installed with a specific radial preload, please refer to catalog SP 1, GMN super-precision bearings. Special attention must be paid to the preload of the thrust bearing. Single bearing solution Due to the size range of thrust/radial bearings YRTS and thrust angular contact ball bearings ZKLDF (see TPI 120, high-precision bearings with combined loads), crossed roller bearings are used here. These bearings are characterized by simple peripheral structure, small design space, and convenient lubrication. The two-bearing solution uses the two-bearing configuration to meet the requirements of most applications. The main method of this kind of bearing arrangement is a preloaded thrust bearing and another bearing, and the other bearing preloads the thrust bearing and realizes the radial guiding function. This kind of bearing solution can meet medium and high speed requirements. Angular contact ball bearings and tapered roller bearings can achieve this function. The three-bearing solution uses the three-bearing configuration to have significant advantages in occasions that require high accuracy and rigidity. However, the increased workload due to installation must be considered. Single bearing solution characteristics In the case of single bearing solution, all loads are borne by a single bearing. This makes the surrounding structure of the bearing simple and compact. In addition, there is no need to align the bearings with each other, and since only one bearing needs to be lubricated, the lubrication becomes relatively simple. Crossed Roller Bearings The rollers of these bearings are inclined relative to the shaft, and the rollers are installed in a continuous cross. Separate the rollers with plastic cages. The machining accuracy of these bearings is P5, and the running accuracy is better than P4. Crossed roller bearings provide adjustable preload or fixed preload. High running accuracy In addition to the crossed roller bearings described here, thrust/radial bearings YRTS and ZKLDF with diameters ranging from 200 mm to 460 mm are also suitable for these applications. Thrust/radial bearings ZKLDF can produce this kind of bearings with a bore diameter of up to 1030 mm. These series of bearings have higher accuracy than THK crossed roller bearings. Please refer to TPI 120, high-precision bearings for combined loads. Compared with the single bearing solution, the two bearing solution features are shared by the two bearings. Thrust bearings mainly bear the weight of the table and workpiece. Angular contact ball bearings are used to provide radial support while simultaneously preloading the shaft system axially. If thrust roller bearings are used, the system can withstand high loads. It is recommended to use thrust ball bearings at higher speeds. During the design and installation process, it must be ensured that the minimum load can be met under various load conditions. This also affects the recommended paired bearing arrangement. In terms of speed, the two-bearing solution using ball bearings is a better choice for friction, lubrication and high precision. Precision size and geometric tolerance accuracy are mainly determined by larger thrust bearings. The radial runout of the system is affected by the angular contact ball bearings with smaller diameters. Solution characteristics of three bearings In this arrangement, the combined load is appropriately distributed to two thrust bearings and one radial bearing. This requires separate consideration of design requirements. The appropriate preload must be selected according to the load-bearing situation to ensure the smallest axial load. Special consideration must be given to lubrication. Although the thrust bearing requires a larger amount of lubricating oil to dissipate heat, it is not necessary for the radial cylindrical roller bearing to have a larger amount of oil at a higher speed. According to the design, the radial bearing can be lubricated by the smaller thrust bearing above in most cases, see page 124. Rigidity The high rigidity of the bearing system can be achieved by the fixed axial preload between the two thrust bearings and the radial preload of the radial bearing. The radial preload is generally up to 5 m, please refer to page 126 Page and catalog SP1, super precision bearings. Accuracy of dimensional and geometric tolerances If each bearing is accurately combined, this bearing configuration can achieve high accuracy.