Abstract: A cartridge seal assembly includes a rotatable seal ring and a non-rotatable seal ring forming a mechanical face seal. A plurality of resilient elements disposed in a housing between a stop surface and the non-rotatable seal ring provide a biasing force to urge the non-rotatable seal ring towards the rotatable seal ring. The non-rotatable seal ring includes an inner axial side opposite the annular non-rotatable seal face that forms a plurality of slots that are arranged peripherally around the inner axial side between adjacent pairs of nubs disposed on and protruding from the inner axial side in a direction away from the annular non-rotatable seal face; wherein each of the plurality of slots abuttingly receives therein a closed end of a respective one of the plurality of resilient elements to provide an anti-rotation function between the housing and the non-rotatable seal ring.

Abstract: Non-contacting cartridge shaft seals prevent leakage loss of process gases in an “oil free” rotary screw compressor or blower, while simultaneously preventing ingress of lubricating oil to the pumping chamber, allowing the compressor/blower to generate process pressure differentials without oil contamination. A compact unitized seal cartridge assembly is provided in the end plates of the pump housing. One of the rotor shafts extends through an aperture in the end plate or housing, between the pumping chamber and oil-lubricated gear/bearing cases. Internal elements have the ability to self-align radially achieving essential concentricity with shaft rotational axes. The rotor shafts or sleeves non-contact relationship during operation allow increased ranges of shaft rotational speeds.