INA ZARN2557-L-TV-A Nadel-Axialzylinderrollenlager (25x57x65)

As a combined needle/thrust bearing, this bearing carries radial and axial loads simultaneously. The principal dimensions are 25x57x65 mm at a weight of 0.592 kg; the further technical details are listed in the specification table. Both load directions run over rollers here, so the radial as well as the axial capacity comes from line contact.

The combined needle roller / axial cylindrical roller bearing unites two rolling element sets in one assembly: the needle roller assembly takes the radial load, the axially arranged cylindrical roller set the longitudinal force. Because both directions carry over rollers and therefore over line contact, the unit reaches a high capacity in both axes within a small envelope and replaces two individual bearings arranged in series.

The ratings apply separately: the radial rating describes the needle set, the axial one the roller set, and neither value supports the other direction. Depending on the version, supplied washers provide the raceways or the surrounding design does; in the latter case the mating faces are to be hardened, ground and made square to the axis. As with every axial roller set, sliding occurs along the roller length, so speed, lubricant supply and heat dissipation must be considered together. Standard bearing steel is through-hardened and covers the usual operating-temperature range.