Usually, the shaft is supported by two
bearings in the radial direction and the axial direction. The bearing on one side is called a fixed end bearing. It bears both radial and axial loads and acts as a relative between the fixed shaft and the bearing housing. The role of axial displacement. The other side is called the free end, only the radial load is applied, and the axial direction can be relatively moved.
Fixed-end bearings must be fixed to both the shaft and the bearing housing. Suitable bearings are bearings that can withstand composite loads, such as deep groove ball bearings, spherical roller bearings, and double or mating angular contact ball bearings or tapered rollers. Sub-bearing. Radial
bearing combinations subjected to simple radial loads, such as cylindrical roller bearings with inner and outer rings without ribs, can be used as fixed-end bearings in combination with deep groove ball bearings or four-point contact ball bearings or two-way thrust bearings. At this time, the second bearing provides bidirectional axial positioning, but must be installed with a radial spacing from the bearing housing. When the shaft is thermally expanded and the length changes, the free end bearing does not squeezing in the bearing. Axial displacement can occur inside the bearing, as well as bearing rings and housings.
"Cross-fixed" refers to a bearing arrangement in which each bearing is unidirectionally positioned in the direction and in the opposite direction. This combination is mainly used for short axes. All radial bearings that can withstand at least one axial load are suitable, including deep groove and angular contact ball bearings, tapered roller bearings and NJ cylindrical roller bearings. When using angular contact ball bearings or tapered roller bearings, In some cases, a preload must be applied.
