Sealing and flow inducing hub assembly

Abstract

A hub assembly with improved sealing and anti-clogging properties comprising a housing body with a central, longitudinal aligned bore. In the embodiment described herein, a rotating shaft unit on a consistency transmitter is disposed inside the central bore. A flow cavity is formed on the distal end of the housing body which directly communicates with the central passageway of a pipeline containing flowing fluid material. The flow cavity is sufficient in size so that fluid material inside the pipeline may freely flow therein during use. Located around the distal opening of the housing body is an inner bushing made of graphite material. Located immediately adjacent to the inner bushing is a compressible bellows seal which imparts a force against the adjacent, outer surface of the inner bushing. The bellows seal which rotates with the rotating drive unit, has a smooth silicone-carbide end surface which is pressed tightly against the end surface on the stationary inner bushing thereby forming a tight seal. A protective shroud is disposed over the bellows seal to adjustably hold the bellows seal on the outer drive shaft and to prevent fluid material from leaking between the drive shaft, the bellows seal, and the inner bushing. Formed on the outer surface of the shroud is a spiral groove which induces an outward flow of fluid material located within the flow cavity on the housing body towards the back side of a low drag coefficient impeller attached to the distal end of the outer drive shaft.