Findling Wälzlager offers needle roller bearings in various sizes and designs. The company also offers themed training courses where experts can delve deep into the subject of needle roller bearings.

"The range of applications for needle roller bearings extends far beyond the automotive industry, where they are used to support pistons," explains Klaus Findling, Managing Director of Findling Wälzlager GmbH. "Due to the small installation space, particularly compact components are required here that can still transmit high forces." Needle roller bearings make this possible. Their distinguishing feature is the thin cylindrical rolling elements. With this design, the highest loads of all rolling bearings can be achieved with a defined cross-section. Needle roller bearings are therefore ideal for applications where only limited installation space is available.

Different types, one product family

The best-known form of this type of rolling bearing is the so-called needle roller and cage assembly - i.e. needle rollers guided in a cage. However, many other designs have since been developed that belong to the needle roller bearing family, including special designs such as yoke and stud type track rollers.

As with ball bearings, a general distinction is made between radial and axial designs for needle roller bearings. Radial needle roller bearings with or without an inner ring can only support radial forces and are designed for medium loads at medium speeds. They are mainly used in gearboxes and in general mechanical engineering. By dispensing with an inner ring, the size can be further reduced. However, in this case the shaft serves as the raceway - in order to achieve the full load-bearing capacity, it must be hardened and ground. This also applies to needle roller and cage assemblies. Here, the bearings run directly on the shaft or housing.

A hardened raceway of 58-64HRC is also necessary for axial needle roller bearings, but can be avoided by using optionally available raceway washers. These designs only absorb axial forces; this is made possible by a flat, stable cage in which several needle rollers are guided next to each other.

Here, too, there is a wide range of designs and components. Depending on the load capacity of the substructure, axial needle roller and cage assemblies can be paired with axial or thrust washers. Multi-row needle roller and cage assemblies for maximum load ratings are used in axial piston pumps, for example, while designs with integrated axial pulleys are installed in lifting gear and auxiliary units of rail vehicles, among other things.

The application determines the nail bearing type

Last but not least, needle roller bearings can also be used in combined radial/axial solutions. For example, a ball and needle roller bearing pairing is suitable for lower axial loads. Combined bearings are particularly straightforward to fit and easy to handle. Compared to conventional solutions, a number of improvements can also be achieved with combined bearings. Instead of two separate bearings, only one compact combined system is installed, which means that less space is required for storage. Combined bearings are usually used in applications where very high forces are exerted, but where only limited installation space is available.

"We are happy to advise on which needle roller bearing design is suitable for the respective application," says Klaus Findling. "It is particularly important to us that our customers always receive the most economical, technologically sensible and reliable solution." Thanks to decades of experience with needle roller bearings, Findling has built up special expertise from which customers benefit. There are a number of things to consider when using needle roller bearings. One example is greasing, which is problematic with needle bearings due to the small installation space: It is difficult to provide enough grease for an optimum lubrication situation. "For lubrication, users should preferably use oil, especially at high speeds, while ensuring a sufficient oil flow," says Klaus Findling. "At medium speeds, an external lubrication option via a lubrication groove or slot is essential, regardless of whether oil or grease is used." At low speeds, lifetime lubrication with grease is also possible. In this case, it is advisable to order the bearing pre-greased for reasons of convenience. In principle, at least lithium complex soap greases should be used for needle bearings due to the special requirements.

From the range: Needle roller bearings from JNS

In the area of needle roller bearings, Findling Wälzlager works together with Japanese manufacturer JNS, among others. "We have been the JNS factory representative in Germany for 16 years," explains Findling. "The company has made a name for itself primarily as a reliable manufacturer of needle roller bearings and cam followers." The needle roller bearings from JNS are characterized, among other things, by an optimized profiling on the rolling elements. This prevents the occurrence of edge stresses and thus ensures a higher load capacity of the components.