Whether in medical technology in the development of ever more powerful computer tomographs or in mechanical engineering in the positioning of workpieces for increasingly complex machining steps: Dynamics and precision sustainably increase the performance of machines and devices. In this article, Gerhard Reininger, Public Relations at Franke explains how the company’s precision bearings meet the highest demands in these categories.
Unlimited possibilities
The decisive difference between an ordinary ball bearing and a Franke wire-race bearing lies in the races. With wire race bearings, the rolling elements do not roll on solid housing rings, but on hardened wires. The flexibility of this principle allows freer and easier design to develop better products. Thanks to their patented technology, Franke wire race bearings offer maximum design freedom without having to compromise on load capacity.
The enclosing construction can be realised in a variety of lightweight materials and its geometry can be optimally adapted to the respective application. Precision-ground race rings made of hardened steel form the heart of every Franke bearing. The 4-point arrangement of the races allows the bearing to be adjusted without play for loads from all directions.
Even the standard range of Franke wire race bearings and slewing rings offers a high degree of variability. Is the focus of an application on dynamics or precision or noise development? Or is a good compromise to be found?
The rotational resistance of a Franke bearing is adjustable and can be adapted to the requirements. Elastomer inserts between the housing and the races decouple the bearing and prevent the transmission of structure-borne noise for particularly low noise development. Many other parameters such as material, housing shape or the condition of the rolling elements can also be varied and adapted to the application. This creates individual solutions with the greatest possible benefit.
Direct drive for maximum dynamics and energy efficiency
Franke wire race bearings with integrated direct drive are characterised by maximum energy efficiency. The integration of the drive motor directly into the bearing makes it possible to dispense with components such as gears and drive pinions and thus with complex lubrication circuits. The moving masses are significantly lower and power loss due to friction is minimised.
The Franke wire race bearing principle also offers the advantage of free choice of material for the housing. The use of lightweight materials such as aluminium, plastic or carbon enables significant weight savings. The motor can thus be dimensioned smaller, resulting in energy savings of up to 30%.
Maximum performance – compact design
Direct drive bearings are particularly suitable for applications where high performance and low space requirements are important criteria. The integration of the complete drive into the bearing housing means that wear-prone assemblies for the conventional transmission of drive power such as toothed belts, shafts or chains can be omitted. This also benefits more precise positioning.
Technology in detail: Wire race bearings create space for motorisation
The drive is integrated directly into the housing. The stationary bearing part forms the stator, the moving bearing part acts as the rotor of the motor. No further or wear-prone components are necessary to set the rotary motion in motion, which increases the efficiency of the system and the service life.
High-performance bearings at the heart of computer tomographs
Franke special bearings for computer tomographs are customized high-performance bearings. They impress with their particularly quiet running and actively contribute to minimizing the noise exposure of patients during treatment. More than 100,000 Franke CT bearings are already in use in medical technology.
In modern computer tomographs, rotating loads of up to 1t in weight are used. The main bearing of the CT scanner is partly responsible for delivering accurate images. Even at high speeds, it must run quietly and with low vibration. Precise concentricity and axial run-out must be guaranteed. Franke special bearings for computer tomographs achieve speeds of up to 400 rpm with a noise level of less than 60 dB (A). Their high precision and smooth running ensure excellent image material through the X-ray unit.
