Rolling bearing type selection-03

Generally speaking, in high-speed working situations, deep groove ball bearings, angular contact bearings, and cylindrical roller bearings should be used; in lower-speed working situations, tapered roller bearings can be used. The limiting speed of tapered roller bearings is generally about 65% of that of deep groove ball bearings, 70% of that of cylindrical roller bearings, and 60% of that of angular contact ball bearings. Thrust ball bearings have a low limit speed and can only be used in lower speed applications.

For the same type of bearing, the smaller the size, the higher the allowable speed. When selecting bearings, attention should be paid to keeping the actual speed lower than the limit speed.

Bearing movement and axial displacement: Normally, a shaft is supported by two bearings separated by a certain distance. In order to adapt to the different degrees of thermal expansion of the shaft and housing, one bearing should be fixed in the axial direction during installation, and the other bearing should be allowed to swim on the shaft (i.e., floating support) to prevent the elongation or contraction of the shaft. stuck phenomenon. Cylindrical roller bearings (original type 2000, type 32000) and needle roller bearings with no ribs in the inner or outer rings are usually used as traveling supports. This is mainly because the internal structure of such bearings allows appropriate axial displacement between the shaft and the shell. . At this time, the inner ring and the shaft, and the outer ring and the housing hole can adopt a tight fit. When non-separable bearings are used as moving supports, such as deep groove ball bearings and spherical roller bearings, the outer ring and the housing hole, or the inner ring and the shaft must be loosely matched during installation to make them axially removable. Swim freely.

Tapered roller bearings, spherical roller bearings and deep groove ball bearings are basically positioning types. When used as non-positioning, they are installed with a loose fit. All thrust roller bearings are locating bearings.

Convenient installation and disassembly of bearings: When selecting a bearing type, you must also consider whether the installation and disassembly of the bearing is convenient. This is especially important for the installation and disassembly of large and extra-large bearings. General angular contact ball bearings, tapered roller bearings, cylindrical roller bearings and needle roller bearings with separable outer rings are more convenient to install and disassemble. Their inner and outer rings can be installed on the shaft or in the shell hole respectively. In addition, spherical roller bearings with tapered holes in the inner diameter and adapter sleeves, double row cylindrical roller bearings and self-aligning ball bearings are also easier to install and disassemble.