A bearing is a circular component of a thrust rolling bearing with one or more raceways. Fixed end bearings use radial bearings that can withstand combined (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, matched tapered roller bearings, NUP cylindrical roller bearings, or NJ cylindrical roller bearings with HJ angle rings.

In addition, the fixed end bearing configuration can include a combination of two bearings:

1. A radial bearing that can only withstand radial loads, such as a cylindrical roller bearing with one ring without a retaining edge.

2. Bearings that provide axial positioning, such as deep groove ball bearings, four point contact ball bearings, or bidirectional thrust bearings.

Bearings that are used for axial positioning must not be used for radial positioning, as they usually have a small radial clearance when installed on the bearing seat.

Reminder from the bearing manufacturer: There are two methods to adapt to the thermal displacement of the floating bearing shaft. Firstly, a bearing that only bears radial loads and allows axial displacement to occur inside the bearing should be used. These bearings include CARB circular ring roller bearings, needle roller bearings, and a cylindrical roller bearing with no retaining ring. Another method is to use a radial bearing with a smaller radial clearance when installed on the bearing seat, so that the outer ring can freely move axially.

1. Locking nut positioning method:

When installing bearing inner rings 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 locking nut (KMT or KMTA series). Bearings with tapered holes are installed directly on the tapered journal and are usually secured to the shaft with a locking nut.

2. Spacer 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, dimensional and shape tolerances also apply to the relevant parts.

3. Positioning of stepped shaft sleeve:

Another method for axial positioning of bearings is to use stepped shaft sleeves. These shaft sleeves are particularly suitable for precision bearing configurations, as they have smaller runout and provide higher accuracy compared to threaded lock nuts. The stepped shaft sleeve is usually used for ultra high speed spindles, for which traditional locking devices cannot provide sufficient accuracy.

4. Fixed end cover positioning method:

When NTB bearings are installed with an interference fit bearing outer ring, one side of the outer ring is usually placed against the shoulder on the bearing seat, and the other side is fixed with a fixed end cover. Fixed end caps and their fixing screws have a negative impact on the shape and performance of bearings in some cases. If the wall thickness between the bearing seat and the screw hole is too small, or the screws are tightened too tightly, the outer race may deform. The lightest ISO size series, the 19 series, is more susceptible to such damage than the 10 series or heavier series.