Millions of clutch spiders are produced every year using polyurethane to be fitted in couplings for drive technologies. These couplings or „clutch-spiders“ as they are often called are used for torque transmission and damping of torsional vibrations. Typical applications are hydraulic pumps for building machinery, tool machines or wind turbines.
In a two year development program, Fietz in cooperation with the Technical University of Chemnitz has developed and testet three thermoplastic polyurethane materials (TPU) with different hardnesses.
These TPU materials have generated new standards for the use in torsional flexible couplings. The manufacturing process is based on injection moulding but with newly defined characteristics to bring out the strength of these materials.
The previous material grades which are currently used for clutch spiders - especially when higher temperatures are applied - are prone to permanent deformation. This is the reason why couplings typically had a limited life-span.
The advantages of the newly developed high performance TPUs by Fietz can be summarized as follows:
• Excellent wear behavior
• Extremely high elasticity and therefore good dynamic properties
• Dispite higher shore hardness, excellent low values for heat build-up
• Low permanent deformation
• Temperature resistance up to 110°C and better
• Smooth and stable motion
• Manufacturing with low cycle times and lowest scrap rates
• Better damping and therefore lower noise emissions
• High precision in positioning
• Much higher product life-time
Fietz has convinced the world-leading manufacture for torsional flexible couplings to test FiPur®-clutch spiders and was implementing them into pre-series.