The main characteristics of ISB double row angular contact ball bearings are that they withstand radial and axial loads acting in both directions and tilting motions and that they can be used for stiff applications. The main peculiarity of this type of bearing is that it is equivalent to two ISB single row angular contact ball bearings set side-by-side with the only difference being that it occupies less axial space.
The range of ISB double row angular contact ball bearings comprises:
• Standard bearings;
• Shielded bearings;
• Bearings with inner ring in two pieces
Basic design bearings They have a contact angle of 30° and the sets of balls are arranged back-to-back. ISB double row angular contact ball bearings of series 32 and 33 offer various advantages in view of their optimised internal design and the lack of filling slots. These bearings offer the benefit of being universally applicable, of withstanding high axial and radial loads and finally of being very quiet. ISB also supplies them with seal rings, shields and with grooves for the seals on the inner and outer rings.
Shielded bearings Their suffix is ZZ and they are designed to be used if the inner ring rotates. If the outer ring rotates at high speed, a slight amount of grease could leak from the bearing. They must not be washed or heated to temperatures beyond 80°.
Sealed bearings The recommended operating temperature range is from -40° to +100° C with maximum peak of +120° for short periods. Their suffix is 2RS, and they have Nitrile-Butadiene-Rubber seals with sheet steel reinforcement fitted against the grooves in the inner ring (Fig. 4). Slight amounts of grease could leak from the inner ring under high operating speeds and temperatures.
Bearings with inner ring in two pieces This is the third and last version in which the ISB double row angular contact ball bearings can be supplied. The bearings of the 33 D range can withstand very high axial loads. This specific kind of bearing has a large number of balls, a contact angle of 45° and special internal clearance. Another special feature is that it is separable, meaning that the outer ring with balls and cage can be fitted separately from the two halves of the inner ring.