Needle roller bearings are essentially cylindrical roller bearings except that their cylindrical rollers have a length 3 to 10 times their diameter (versus a length less than 3 times their diameter). Needle bearings are also essentially bearings that utilize small & cylindric rollers. Therefore, the ratio of the bearing outside diameter to the inscribed circle diameter is small, and they have a rather high radial load capacity.

Needle roller bearings NK series that have metric dimensions, precision ground raceways with ribs, without Inner Rings, cage guided rollers, with/without Seals. And it has no inner ring, therefore they’re lighter than needle roller bearings of the series NKI. They can be mounted directly on the shaft. They support relatively high radial loads and allow higher speeds.

Needle roller bearings without an inner ring are an excellent choice for compact bearing arrangements if the shaft can be hardened and ground. Eliminating the need for a separate inner ring enables a larger shaft diameter and a stiffer arrangement. Axial displacement of the shaft relative to the housing is only limited by the width of the raceway on the shaft. By machining the shaft raceways to the appropriate dimensional and form accuracy, it is possible to obtain bearing arrangements with heightened running accuracy.

Application

Needle roller bearings are ideal for many of the following applications: transmissions, transfer cases, engines, valve trains, steering and braking systems, axle supports, outboard engines, textile industry, power tools, copiers, fax machines, paper-moving equipment, and appliances.