Wire race bearing

Wire roller bearings are roller bearings with the special property that the rollers run directly on the inner and outer ring, but on hard and tough open race rings that are inserted directly into the slots or recesses of the mating structure. When the rolling elements are used mostly in a cage held balls or rollers. Similar to the surface or through hardened bearings, there are a variety of types, which can be manufactured as a wire roller bearing.

The wire was invented in 1934 by Rolling Erich Franke, co-founder of Franke and Heydrich KG, Aalen / Wuertt. (today Franke GmbH). As a young engineer of the Carl Zeiss works in Jena Franke was looking after a particularly space- saving storage for an optical device. The aim of the consideration was an even closer relationship of the storage in the mating structure in order to make them as compact as possible and easily.

Types

Frequently wire roller bearings are made ​​of each with an inner and an outer ring. For special applications, e.g. must compensate for angular misalignment of the inner and outer ring, also variants with three or more rings are used. Other variants form angular contact ball bearings, tapered roller bearings or triple-row roller bearings, the rolling bodies in two or more rows roll on each other. A variant to accommodate purely axial forces is the thrust bearing. A variant to accommodate purely radial forces is the radial bearing. For both only two profiled outer wires are needed.

Compared with standard ball bearing

The particular advantage of bearing wire is in space-saving design with high load capacity and force balance from all directions. Since the rolling elements roll on the running wires, the mating structure is not directly exposed to the stresses of the rolling elements, and therefore, alternative materials such as aluminum or plastics can be used. Enclosing structures can for example also be external and / or internal gear rings of gears. Another advantage is that it can be adjusted very precisely in wire rolling bearings of the rotary resistance or bias. In addition, the running wires can adjust under load in the load direction. Thus, for especially in multi-row roller bearings, low and uniform rotation resistors also realize at deformations of the adjacent construction and the surrounding rings. Suitable materials for the running wires curable, stainless materials can be used. When ready to install bearings, the rings can also be protected against corrosion.

Besides many advantages wire roller bearings also have systemic disadvantages such as higher installation costs by the insertion of the races in the enclosing structure. Special care is required to ensure proper function. Therefore, preferably pre-finished wire roller bearings are used where the wires run, rolling elements and cages already mounted in the surrounding rings and the desired storage function values ​​such as Preload and running accuracies are set.

Examples of use of wire rolling bearings

Wire Rolling frequently then used when the installation space for storage is very tight or light construction as possible should be sought.

• Rotary connection with 4- point support - rotational resistance tuned by means of the threaded ring.
• Angular contact ball bearings are widely used in bearings for CT scanners.
• 3 -point bearing, for example, compensate for angular displacement; here with toothed outer ring.
• 4 -point bearing consisting of two running wires, primarily to support radial forces.
• 4 -row wire roller bearings, a modification of the three-row roller bearing wire.
• Wire cross roller bearing.
• Double-row tapered roller bearing wire with external teeth.