Engineers at NTN Bearing Corp., Mt. Prospect, Ill. (ntnamerica.com), redesigned the company's offering, developing the Ultra Class mounted bearing. It features a full-contact molded rubber seal bonded to a steel backing plate. The seal lip rides on the inner ring which has been precision ground to a smooth finish. A metal flinger pressed onto the inner ring protects the seal lip. Triangular fins on the outside face of the flinger act as fans, sending air, dust, and water away from the bearing as it rotates. The bearings come with a setscrew or an eccentric locking collar, and both have a ball-point setscrew with a hardened steel ball (HRc 62).
Tightening the screw squeezes the ball into the tapered section of the setscrew, spreading the threads. This reduces the risk of the screw loosening due to vibration or shock. The ball-point design also increases holding force.
The bearings' concentricity and roundness are kept within tight tolerances. A precise fit between the bearing and housing bore, for example, eliminates the need for antirotation devices used by other bearing manufacturers. The tolerances also contribute to long life, rotational accuracy, and quiet operation. The bearings are available with cast-iron pillow blocks or flange-styled housings.
