There are many types of rolling bearings for machine tools. When selecting one, you can consider the following factors.
① Load Magnitude, Direction, and Nature: Ball bearings are suitable for light loads, while roller bearings are suitable for heavy loads and impact loads. When a rolling bearing is subjected to a pure axial load, a thrust bearing is generally selected; when a rolling bearing is subjected to a pure radial load, a deep groove ball bearing or a short cylindrical roller bearing is generally selected; when a rolling bearing is subjected to a pure radial load along with a small axial load, a deep groove ball bearing, an angular contact ball bearing, a tapered roller bearing, or a self-aligning ball or self-aligning roller bearing can be selected; when the axial load is large, an angular contact ball bearing with a large contact angle and a tapered roller bearing can be selected, or a combination of a radial bearing and a thrust bearing can be selected, which is particularly suitable for extremely high axial loads or when a large axial rigidity is required.
② The permissible speed varies greatly depending on the type of bearing. Generally, bearings with low friction and low heat generation are suitable for high speeds. During design, rolling bearings should be designed to operate below their limiting speed.
③ When a rigid bearing is subjected to a load, elastic deformation will occur at the contact point between the bearing rings and the rolling elements. The amount of deformation is proportional to the load, and the ratio determines the magnitude of the bearing rigidity. Generally, the bearing rigidity can be improved by preloading the bearing; in addition, considering the combination and arrangement of bearings in the bearing support design can also improve the bearing support rigidity.
④ Self-aligning performance and installation errors: After bearings are installed in their working position, poor installation and positioning often occur due to manufacturing errors. This can lead to excessive loads on the bearings due to shaft tilting and thermal expansion, causing premature damage. Self-aligning bearings can overcome defects caused by installation errors, making them suitable for such applications.
⑤ Installation and disassembly of tapered roller bearings, needle roller bearings, etc., are types of bearings with separable inner and outer rings (i.e., separable bearings), which are convenient to install and disassemble.
⑥ Market availability: Even horizontal lathe bearings listed in the product catalog may not be available on the market; conversely, some bearings not listed in the product catalog are produced in large quantities. Therefore, it is important to determine whether the bearings used are readily available.
