The impact of the quality of bearing configuration on operation

Usually, a shaft is supported by two bearings in the radial and axial directions. One side of the bearing is called a fixed end bearing, which bears both radial and axial loads and plays a role in fixing the relative axial displacement between the shaft and the bearing housing. The other side is called the free end, which only bears radial loads and can move relatively axially.

Fixed end bearings must be fixed to both the shaft and the bearing housing. A more suitable bearing is a radial bearing that can withstand composite loads, such as deep groove ball bearings, self-aligning roller bearings, double row or paired angular contact ball bearings, or tapered roller bearings. Radial bearing combinations that can withstand simple radial loads, such as cylindrical roller bearings with inner and outer rings without ribs, combined with deep groove ball bearings, four point contact ball bearings, or bi-directional thrust bearings, can also be used as fixed end bearings. At this point, the second bearing provides bi-directional axial positioning, but must be installed with a certain radial distance from the bearing housing. When the length of the free end bearing changes due to thermal expansion of the shaft, there will be no compression inside the bearing. Axial displacement can occur inside the bearing or between the bearing ring and the bearing seat.

Cross fixation "refers to a bearing configuration in which each bearing is positioned unidirectionally and in opposite directions to the shaft. This combination is mainly used for short axes. All radial bearings that can withstand axial loads in at least one direction are suitable, including deep groove and angular contact ball bearings, tapered roller bearings, and NJ type cylindrical roller bearings. When using angular contact ball bearings or tapered roller bearings, preload must be applied in certain situations.

One In the stage of bearing selection, many factors need to be considered (such as load, hardness, operating environment, etc.), and a good bearing design will first enable the bearing to reach its maximum life value.

II Proper storage, bearings should be stored in their original packaging before installation. It needs to be kept in a clean, moisture free, and relatively constant temperature environment. Rolling bearings should be kept away from dust, water, and corrosive chemicals. Shaking and vibration may permanently damage the mechanical performance of bearings, so vibration should be avoided during handling and storage. Generally, bearings should be stored horizontally. Some heavier bearings may deform due to their own weight after being placed vertically for a long time! Also, bearings coated with grease (or sealed) require special care as the density of the grease may change after prolonged storage. When the bearing is used for the first time, there will be a certain degree of rotational noise. So, the shelving time of such bearings should be controlled according to the principle of first in, first out!