A barrel coupling consists of an internally toothed sleeve and an external toothed hub. The teeth are forming holes that are filled with cylindrical barrels. The barrels work as transmission elements between hub and sleeve. Covers and seals are protecting the barrels from dust and dirt intrusion. The inner zone is greased. One retainer ring on each side of the barrels is limiting the axial float of the coupling. The crowned shape of the barrels allows an angular misalignment of ±1°. The axial misalignment depends on the coupling size. It goes from ±3mm up to ±10mm. The torque is transmitted by the flat face flange that has to be accurately slotted in the rope drum. The hub bore can be machined with key fit, a spline fit or a hydraulic fit.
There are two executions:
The basic model type NT where the retainer rings are in direct contact with the barrels. Model NTRSG with additional pressure rings between the barrels and the retainer rings. The NTRSG version is in accordance with the German Steel Industry Standard (SEB 666212) and the French Steel Industry Standard.
