NTN 4T-34306/34478 Kegelrollenlager (77,788x121,442x24,608)

As a tapered roller bearing, this bearing carries high combined radial and one-directional axial loads and is usually adjusted in pairs. The mounting dimensions are 77.788x121.442x24.608 mm and the weight is 0.968 kg; technical details beyond these are shown in the specification table. The tapered arrangement of inner ring, roller set and outer ring brings the load lines together at a common point on the bearing axis and carries radial and one-directional axial loads together.

Tapered roller bearings transmit load through tapered rollers between tapered raceways whose extended surface lines meet at one point on the bearing axis; this is where the combination of high radial and one-directional axial capacity that characterises the design comes from. Because axial force is supported in one direction only, the bearing normally works against a second bearing adjusted against it in a back-to-back or face-to-face arrangement.

Operating clearance is therefore not preset in the bearing but established during mounting as the two units are adjusted against each other; the adjustment travel, the preload and the thermal behaviour of the surrounding design determine it jointly. The inner ring with its roller and cage assembly and the outer ring are separable, so both rings can be fitted with an interference fit.

For the design, the contact angle, the chosen adjustment method and the equivalent load resulting from the axial share should be drawn upon.