Positioning and installation method of self-aligning roller bearings

A bearing is an annular component of a thrust rolling bearing with one or several 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, paired tapered roller bearings, NUP type cylindrical roller bearings, or NJ type cylindrical roller bearings with HJ angle rings

In addition, the fixed end bearing configuration can include a combination of two bearings: 1. Radial bearings that can only withstand radial loads, such as cylindrical roller bearings with one ring without a flange

2. Provide bearings with axial positioning, such as deep groove ball bearings, four point contact ball bearings, or bi-directional thrust bearings

Bearings 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

Bearing manufacturers remind that there are two methods to adapt to the thermal displacement of floating bearing shafts. Firstly, a bearing that can only withstand radial loads and allow axial displacement to occur inside the bearing should be used. These bearings include: CARB ring roller bearings, needle roller bearings, and a cylindrical roller bearing with a ring without a stopper. 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 move freely in the axial direction

1. Locking nut positioning method:

When installing the inner ring of a bearing with interference fit, usually one side of the inner ring is 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 directly installed on tapered shaft necks and are usually secured to the shaft with locking nuts

2. Spacer positioning method:

It is convenient to use spacers or spacers between bearing rings or between bearing rings and adjacent parts, instead of integral shaft shoulders or bearing seat shoulders.

. In these cases, dimensional and shape tolerances also apply to the relevant parts

3. Positioning of stepped shaft sleeves:

Another method of axial positioning for bearings is to use stepped shaft sleeves.

. These shaft sleeves are particularly suitable for precision bearing configurations, with smaller runout and higher precision compared to threaded locking nuts. Stepped shaft sleeves are commonly used for ultra high speed spindles, for which traditional locking devices cannot provide sufficient accuracy

4. Fixed end cover positioning method:

When installing the outer ring of Wafangdian bearings with 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.

. Fixed end caps and their fixing screws can 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 if the screw is tightened too tightly, the outer raceway may deform. The lightweight ISO size series 19 series is more susceptible to such damage than the 10 series or heavier series