Electric drives are becoming more powerful, compact and dynamic. This fact has consequences for torsionally flexible couplings that compensate for misalignment, damping shocks and also to increase the service life of the drive system. Often the environments in which the likes of gearboxes and pumps are used in are not fully known in advance. That is why well-approved spider compounds have to face their limits from time to time. In high ambient conditions spiders from PEEK or other expensive special compounds have to be used. That is why KTR have searched for a new material with a wider application range for the ROTEX jaw couplings; having performed extensive tests in cooperation with leading manufacturers of nylon they have identified the material T-PUR. The new material is characterised, among others, by a wider temperature range: While the usual spider materials are applicable with temperatures from -30 to +90 °C, T-PUR is suitable from -50 to +120 °C. The fatigue strength is clearly improved, which means that the service life of the coupling system is increased and the maintenance intervals can be extended. Even with higher dynamic loads, for example variable speeds and frequent reversing operation, T-PUR has proven to be the better material. The new material is used for the standard spiders of ROTEXjaw couplings from size 14 to size 90. Depending on the requested damping behaviour, various degrees of hardness or flexibility from 92 Sh-A to 64 Sh-D are available. From size 100 the company delivers double tooth elements, manufactured from the new material as well. The spider materials were tested under actual operating conditions in many different applications and on such applications where previously they used standard elastomers were not in a position to guarantee the necessary fatigue strength or temperature resistance, respectively.
Edited by: Teoman Tugsuz