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Portrait of the needle bearing

By , mardi le 26 mars 2019, 11:48

The needle bearing has some unique features that distinguish it from other types. They are very wide and are able to withstand high axial loads where the space between the shaft and its housing is restricted. The needle bearing is therefore particularly useful in applications having restricted overall dimensions.


The main types of needle bearings

Several kinds of needle bearings are available. The main differences lie in the composition of the parts and the type of application. Here are the main models of needle bearings and their characteristics.


Needle bearing with edges

The special feature of the needle bearing with edges is that the outer ring and the needle cage cannot be separated. This bearing is specifically used for applications with small radial dimensions. There are also some variations to this model, such as the number of rows and the presence or absence of an inner ring.

In addition, it is possible to add a sealing ring adapted to the needle bearing. The lubrication of the rings is necessary to maintain good functioning, the outer ring is thus provided with a hole and a groove for lubrication and easy maintenance. Depending on the type of ring used, the temperature extremes of the needle bearing with edges vary between -20 ° C and 120 ° C.


Needle bearing without edges

Unlike the previous model, the inner ring, the outer ring and the needle bearing cage without edges can be mounted separately. Mounting is therefore much easier. The other features of this type of bearing are similar to those of the needle bearing with edges. The only distinction is made at the outer ring.


Self-aligning needle bearing

This needle bearing model has an outer ring with a sphered (convex) outside surface. Two polymer seating rings with a sphered (concave) inside surface are encased in a drawn sheet steel sleeve and fitted over the outer ring. Although it somewhat compensates for static misalignments, the self-aligning needle bearing is not designed for oscillating movements. This bearing can function without an inner ring. A model without an inner ring will be preferred if the shaft is hardened and ground.  The self-aligning needle bearing must be lubricated regularly with oil or grease. The latter can also function in various temperatures ranging from -20 ° C to 100 ° C.


Combined needle bearing

This model is composed of a thrust needle bearing and a needle cage. This composition gives it the particularity of being able to withstand axial loads in one direction and radial simultaneously. These bearings do not allow misalignment between the shaft and the housing. On the market, three variants of this type of bearing exist: the models with thrust bearings, with cylindrical roller thrust bearings and with angular contact balls. Bearings without an inner ring are used if the shaft is hardened and ground.

Being more compact, the combined needle bearing is able to operate in more restricted areas. It is its large number of rolling elements that allows the combined needle bearing to offer a higher load capacity than other types. Like needle bearings with edges and no edges, the combined needle bearing can operate in temperatures varying between -20 ° C and 120 ° C.