Screw connection between fan vane and liquid friction coupling

摘要

The screw connection links the vane to the coupling so that it can be released. The vane (2) has a central circular aperture (7) with projections in the form of screw segments (8) round its circumference, forming a collar. The segments form an internal thread. This thread enables the vane to be screwed onto an external thread (10) on the coupling (1), co-axially with its central axis (9). The wheel may have a recess (6) for an assembly support ring (5) to be fitted to the coupling, in which case the circular aperture is in the support ring.