SEALING DEVICE FOR ROTATING SHAFTS, IN PARTICULAR MIXER ROTOR SHAFTS, AND METHOD FOR IMPLEMENTING SAME

摘要

A seal assembly for the rotor shafts of internal mixers and the like used in the compounding of rubber and plastic. The assembly (20, 100) comprises seal rotor (21) carried by the rotor shafts (15, 16) outside of the mixing chamber (14) of the mixer (10) and having a continuous circumferential portion (24) for the bi-directional movement of a viscous melt of flowing material, sleeve (22) non-rotatably carried by the housing (18) of the mixer concentrically disposed about the seal rotor, and retainer (23) rotatable with the rotor shaft and engageable with the seal rotor (21) so as to cause the seal rotor to rotate therewith, wherein movement of the flowable material between the continuous circumferential portion and the sleeve forms a dynamic melt seal thereby controlling the discharge of materials from the mixing chamber between the housing and the rotor shaft. A method for controlling the discharge of materials from the mixing chamber (14) of an internal mixer (10), having at least one rotatable rotor (11) providing opposed shafts (15, 16 ) which pass through the housing (18) of the internal mixer (10), includes the step of continuously providing a flow of viscous melt material within the continuous circumferential portion to form a dynamic melt seal between the seal rotor and the sleeve of the seal assembly, thereby controlling the discharge of materials from the mixing chamber between the housing and the rotor shaft.