NTN HK2018 L/3AS Nadelhülsen (20x26x18)

As a needle roller bearing, this bearing carries high radial loads in a very compact section. The principal dimensions are 20x26x18 mm at a weight of 0.026 kg; the further technical details are listed in the specification table. This variant features a contact seal. Only one end face of the cup is closed with a contact seal; this fixes the mounting orientation of this version.

This drawn cup needle roller bearing is closed at one end face with a contact seal while the other remains open. Mounting is therefore orientation-bound, and the mounting position belongs in the layout: the sealed side faces the side from which dust, chips or splash water comes, or at which an escape of lubricant is to be avoided; the open side faces where a component bounds the rolling chamber in any case — against a locating face, into a blind bore, against an adjacent bearing position — or where lubricant is deliberately supplied.

Compared with the version sealed on both sides, two practical differences arise: only one frictional torque occurs, at one lip instead of two, which benefits the permissible speed, and the rolling chamber remains accessible from the open side for replenishing lubricant. The restriction is equally clear, since the needle set is protected from one side only.

The mounting conditions of the design remain unchanged: the thin-walled, drawn cup takes on the form of the housing bore as it is pressed in, so that bore has to be closely toleranced, accurate in form and load-bearing; without a separate inner ring the shaft surface is the raceway and has to be hardened and ground accordingly; the design takes no axial force, and the long contact line of the needles permits only slight misalignment. The seal material limits the operating temperature and the media resistance.