Positioning and installation mode of self-aligning roller bearing


Bearing is an annular part of 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, matched tapered roller bearings, NUP cylindrical roller bearings or NJ cylindrical roller bearings with HJ angle rings.


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


1. Radial bearings that can only bear radial load, such as cylindrical roller bearings with one ring and no flange.


2. Provide axially positioned bearings, such as deep groove ball bearings, four point contact ball bearings or two-way thrust bearings.


The bearing for axial positioning must not be positioned radially. It is usually installed on the bearing seat with small radial clearance.


The bearing manufacturer reminds that there are two methods to adapt to the thermal displacement of floating bearing shaft. First, use a bearing that only bears radial load and allows axial displacement to occur inside the bearing. These bearings include carb ring roller bearing, needle roller bearing and one ring cylindrical roller bearing without retaining edge. 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 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 generally fixed with a lock nut (KMT or KMTA Series). Bearings with tapered holes are mounted directly on tapered journals and are usually fixed to the shaft with lock nuts.


2. Spacer positioning method:


It is convenient to use spacer sleeves or spacer rings between bearing rings or between bearing rings and adjacent parts to replace the integral 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 of bearing axial positioning is to use stepped shaft sleeve. These bushings are particularly suitable for precision bearing configurations, with less runout and higher accuracy than threaded lock nuts. Stepped shaft sleeve is usually used for ultra-high speed spindle. For this kind of spindle, the traditional locking device can not provide it with sufficient accuracy.


4. Fixed end cover positioning method:


Wafangdian Bearing adopts interference fit bearing outer ring. When installing, one side of the outer ring is usually against the shoulder on the bearing seat, and the other side is fixed with a fixed end cover. The fixed end cap and its fixing screws have a negative impact on the shape and performance of the bearing in some cases. If the wall thickness between the bearing pedestal and the screw hole is too small, or the screw is tightened too tightly, the outer race may be deformed. The lightest ISO size series, the 19 series, is more susceptible to such damage than the 10 series or heavier series.