NTN 89308 Axial-Zylinderrollenlager (40x78x22)

As an axial cylindrical roller bearing, this bearing carries very high axial loads in a low section height. At 40x78x22 mm and a unit weight of 0.51 kg, the installation envelope is fixed; further technical details are held in the specification table. Because a cylindrical roller passes through differing circumferential speeds along its length, the resulting slip governs the speed and lubrication behaviour of this arrangement.

The axial cylindrical roller bearing transmits longitudinal force through cylindrical rollers running between two flat washers; the line contact yields a markedly higher axial capacity than a ball arrangement of comparable section height. The design takes no radial forces — the shaft is to be guided radially elsewhere, and the seating faces must be square to the axis.

The effective radius changes along the roller length, so sliding between roller and washer is unavoidable; this slip limits the speed and places raised demands on the lubricant film and heat dissipation. For the same reason a permanently acting minimum axial force should be provided so that the roller set is not dragged along unloaded. Standard bearing steel is through-hardened and carries the raceway loading within the usual operating-temperature range; for the design, axial force, speed, lubricant viscosity and heat dissipation should be assessed together.