Creswell, a leader in the supply of bearing units, is introducing the Ultra-Class mounted unit series. Creswell’s research along with extensive experience in original equipment and the aftermarket has led to their unique features that take mounted units to an elevated level of design and performance.
Bearing units are implemented in a vast number of applications because they are versatile, easy to mount and simplify the design process. Creswell has a long history of providing customers with numerous alternatives for general industry and meeting modern demands for performance. The Ultra-Class series further supports this effort by offering ultimate sealing, efficient locking, and integrated precision in one robust package.
Ultra-Class inserts utilize a full contact molded rubber seal that is bonded to a steel backing plate. The seal lip rides on the inner ring which has been precision ground to provide a very smooth contacting surface. The metal flinger that protects the seal lip is pressed onto the inner ring. There are triangular fins (protrusions) on the outside face of the flinger; these fins create an outward flow of air from the bearing as the bearing rotates. In this way, the flinger acts as a fan which keeps dust and water away from the bearing. The labyrinth effect between the flinger/seal combination is very effective in highly contaminated applications.
Figure 1 - Flinger/Seal Combination
Ultra-Class units are available with set screw or eccentric collar locking designs. Either selection is supplied with NTN’s exclusive ball point set screw. The ball point set screw features a hardened steel ball (HRC 62) that is retained in the end of the set screw. This design has several advantages over competitive designs:
• Threads positively engage—Upon tightening, the steel ball is squeezed back into the tapered portion of the set screw, causing the threads to spread. This expansion of the threads makes it extremely difficult for the set screw to loosen when exposed to vibration and/or shock loads.
• Develops larger holding force—The ball point set screw makes point contact with the shaft allowing easy tightening and complete transmission of force to the shaft. On the other hand, the cup point or knurled cup point set screw designs make circular contact with the shaft. In these designs, a portion of the tightening torque is ultimately used to cut a circular groove on the shaft and thus reduces the holding force.
Figure 2 - Ball Point Set Screw Design
• Can be used repeatedly—The hardened steel ball does not deform when tightened and only leaves a small concave print on the shaft. Conversely, the cup point set screw not only marks the shaft, but the screw itself becomes damaged, reducing its effectiveness if retightened after removal.
Ultra-Class inserts are consistently manufactured to tight tolerances for concentricity and roundness. The precise fit between the bearing and housing bore eliminates the need for anti-rotation devices used by other manufacturers. These qualities when combined with it’s superior steel cage design and excellent quality control practices allows these units to provide greater rotational accuracy, quiet operation, longer life and contribute to higher speed capability.
Ultra-Class series is available in a high quality cast iron pillow block or flange style housing specifically designed to provide high rigidity and strength for Heavy Duty applications. Pillow blocks are supplied with a solid base and grease fitting located at a 45º angle as standard. All Creswell Ultra-Class units have a unique metallic name plate showing the complete part number for the unit. This name plate provides permanent and durable part number identification for easy identification.
| 
