A bearing is a ring part of a thrust rolling bearing with one or more raceways. Fixed-end bearings use radial bearings that can withstand joint (radial and axial) loads. These bearings include: deep groove ball bearings, double row or paired single row angular contact ball bearings, self-aligning ball bearings, self-aligning roller bearings, tapered roller bearings with matching, NUP type cylindrical roller bearings or NJ type cylindrical roller bearings with HJ Angle ring.
In addition, the fixed-end bearing configuration may contain a combination of two bearings:
1. Radial bearings that can only bear radial load, such as cylindrical roller bearings with one of the rackets without retaining edges.
2, provide axial positioning bearings, such as deep groove ball bearings, four-point contact ball bearings or two-way thrust bearings.
Bearings for axial positioning must not be radial positioning, usually with a small radial clearance when installed on the bearing seat.
Bearing manufacturers remind: there are two ways to adapt to the thermal displacement of the floating bearing shaft. The first step is to use a bearing that only bears radial load and allows axial displacement to occur inside the bearing. These bearings include: CARB ring roller bearings, needle roller bearings and a cylindrical roller bearing with a ring without a baffle. Another method is to use a radial bearing with a small radial clearance when mounted on the bearing housing so that the outer ring is free to move axially.
1. Locking nut positioning method:
When installing the bearing inner ring with interference fit, one side of the inner ring is usually against the shoulder on the shaft, and the other side is usually fixed with a lock nut (KMT or KMTA series). Bearings with tapered holes are mounted directly on the tapered journal, usually fixed to the shaft with lock nuts.
2. Nesting positioning method:
It is convenient to use spacers or spacers between bearing rings or between bearing rings and adjacent parts to replace the overall shaft shoulder or bearing seat shoulder. In these cases, size and shape tolerances also apply to the relevant parts.
3. Positioning of step bushing:
Another method of bearing axial positioning is to use step bushing. These bushings are particularly suited for precision bearing configurations, providing less run-out and greater accuracy than threaded lock nuts. Step bushings are commonly used for ultra-high speed spindles for which conventional locking devices do not provide sufficient accuracy.
4. Positioning method of fixed end cover:
When Wafangdian bearings are installed with the bearing outer ring of interference fit, usually one side of the outer ring is against the shoulder on the bearing seat, and the other side is fixed with a fixed end cover. The fixed end caps and their fixed screws have a negative impact on bearing shape and performance in some cases. If the wall thickness between the bearing seat and the screw hole is too small, or the screw tightening is too tight, the outer ring raceway may be deformed. The lightest ISO size series 19 series are more susceptible to such damage than the 10 series or heavier series.