ISB® spherical roller bearings have two rows of rollers that roll in one spherical raceway in the outer ring (Fig. 1). The two corresponding raceways of the inner ring are set at an angle compared to the bearing’s axis. They are self-aligning and insensitive to slight misalignments of the shaft compared to the housing and to shaft deflections. They withstand radial and axial loads in both directions.
The spherical rollers bearings are:
Open bearings: based on the size and series, they are manufactured in various versions, available with tapered or cylindrical bore. The tapered bore has a taper of either 1:30 (series 240,241,248 and 249, designation suffix K30) or of 1:12 with designation suffix K. The circumferential groove and three lubrication holes in the outer ring facilitate bearing lubrication (Fig. 2).
Sealed bearings: The seals are reinforced with steel and are made of Nitrile-Butadiene-Rubber (NBR), they are lubricated with grease for very high pressures and must not be heated above 80°C or washed (Fig. 3).
• Bearings for vibratory applications: Vibratory applications, such as vibrating screens or energisers, subject the bearings to greater strain than standard bearings.
The dimensions comply with standard ISO 15:1998. The dimensions of the adapter or withdrawal sleeves comply with standard ISO 2982-1:1995.
ISB spherical roller bearings with tapered or cylindrical bore are manufactured with Normal tolerance.
ISB spherical roller bearings are manufactured with Normal internal radial clearance. They are mostly available also with greater internal clearance C3 and much greater clearance C4. Some are supplied with internal clearance C2 that is smaller than Normal. Always check availability of internal clearances different to standard before placing orders (including C5, greater than C4).
Angular misalignments do not affect the performance of this type of bearing thanks to its constructional design.
Axial load carrying capacity
These bearings withstand strong axial loads thanks to the special internal constructional design.
C2 Internal radial clearance smaller than Normal.
C3 Internal radial clearance greater than Normal.
C4 Internal radial clearance greater than C3.
C5 Internal radial clearance greater than C4.
2RS Nitrile-Butadiene-Rubber contact seal (NBR), with sheet steel reinforcement, on both sides of the bearing. Circumferential groove and three lubrication holes in the outer ring.
K Tapered bore, taper 1:12. K30 Tapered bore, taper 1:30;
P5 Greater dimensional and rotation precision, compliant with tolerance class 5 of ISO standard.
P6 Greater dimensional and rotation precision, compliant with tolerance class 6 of ISO standard
P62 P6 + C2
VA Bearings for vibratory applications
W33 Circumferential groove and three lubrication holes in outer ring