Needle Bearing

Needle bearings are very versatile and come in a wide variety of types. To accurately determine the application, it is helpful to understand the differences between the types. Essentially, we distinguish needle bearings into the following categories:

• Drawn cup needle roller bearings open-ended and drawn cup needle roller bearings closed-ended

  They consist of a seamless outer ring and a needle cage, which together form a unit. Advantages include a very low cross-sectional height and high load capacity. They are used where space-saving and cost-effective bearings are desired. Drawn cup needle roller bearings open-ended and drawn cup needle roller bearings closed-ended are usually used without an inner ring. In cases where the shaft cannot be hardened and ground, inner rings can be used. Sealed drawn cup needle roller bearings open-ended and drawn cup needle roller bearings closed-ended have sliding seals made of polyurethane or synthetic rubber and are lubricated with high-quality lithium soap grease. Sealed drawn cup needle roller bearings open-ended and drawn cup needle roller bearings closed-ended can be used at temperatures between –20°C and +100°C. For drawn cup needle roller bearings open-ended and drawn cup needle roller bearings closed-ended, precise sizing and shape of the housing bore are particularly important. The inner running circle diameter of the needle rollers then falls within the F8 tolerance field.

• Needle bearings

  They have a lubrication groove and a lubrication hole in the outer ring. The outer ring has flanges. Together with the needle cage, it forms a unit. Needle bearings without an inner ring offer an optimal solution where the shafts are hardened and ground. Without the tolerances of the inner ring, higher running speeds can be achieved. Needle bearings with an inner ring are used where hardening and grinding are not possible or economically justifiable. In all bearings, the outer ring, needle rollers, and cage form a self-retaining unit. The inner ring can be mounted separately. The bearings of series RNA 69 and NA 69 with a diameter from 55 mm have two guided needle cages. Single-sided and double-sided sealed needle bearings have sliding seals made of synthetic rubber. They are filled with lithium soap grease and can be used at operating temperatures from -20°C to +100°C. Due to better sealing performance, the inner ring is 1 mm wider than the outer ring, ensuring that no contaminants enter the bearing during axial shifts of the shaft relative to the housing.

• Combined needle bearings

  Combined needle bearings are units consisting of a radial needle bearing and an axial load-capable rolling bearing. The axial load-capable part of the bearing can be made up of a deep groove ball bearing, a cylindrical roller bearing, or an angular contact ball bearing. Combined needle bearings are characterized especially by their ability to accommodate high radial forces as well as unilaterally acting axial forces, and they are used as fixed or support bearings. Combined needle bearings are not self-retaining. The bearing parts (axial part / radial part) are matched to each other and must not be interchanged during assembly.