Type of Bearing	Self Aligning
Dimension	30 X 40 mm
Usage/Application	Industrial
Material	Mild Steel
Brand	SKF
Country of Origin	Made in India

Self-aligning ball bearings have two rows of balls, a common sphered raceway in the outer ring and two deep uninterrupted raceway grooves in the inner ring. They are available open or sealed. The bearings are insensitive to angular misalignment of the shaft relative to the housing (fig. 1), which can be caused, for example, by shaft deflection.

Basic Design

Self-aligning bearings of the basic design are available with both a cylindrical bore and a tapered bore with a 1:12 taper. Tapered bore bearings are furnished with adapter sleeves, including nut and lock washer, with which the bearings can be secured to smooth or stepped shafts. They are identified by suffix letter K.

Sealed Bearings

Self-aligning bearings with cylindrical and tapered bores are available with contact seals on both sides, identified by the suffix 2RS1. The seals are made of oil and wear resistant synthetic rubber reinforced by a steel insert. The operating temperature range for the seals, with a suitable grease, is -40 Degree Celsius to 120 Degree Celsius. Sealed bearings are supplied with a lithium base grease suitable for an operating temperature range of -30 Degree Celsius to 110 Degree Celsius. Sealed bearings with a tapered bore require a special adapter sleeve and lockwasher identified by the suffix letter C. The lockwashers have a circular beading on the side facing the bearing to prevent interference with the seal. 

Extended Inner Ring Bearings

Self-aligning bearings with an extended inner ring are used in applications employing commercial ground shafting. A special bore tolerance allows easy mounting and dismounting. 
These bearings are located axially by pins or shouldered screws which engage in a slot at one side of the inner ring. The pins or screws also prevent the inner ring from turning on the shaft. When used in pairs, the slots on the inner ring must either be adjacent or at the outboard positions to provide shaft location in both directions.

Tolerances

Self-aligning bearings are manufactured to ABEC-1 tolerances as shown on page 241. The exceptions are the bore and inner ring width on extended inner ring bearings, which are manufactured to the tolerances shown in the table below.