Roller cutter assembly with improved bearing seal ring

Claim 1

In combination, a rock boring cutter assembly including: a rotary cutting wheel having an external surface configured to engage and break rock formations; mounting means for said cutting wheel including a frame recessed snugly to surround a portion of a side and the ends of said cutting wheel and having a portion adapted to be mounted on the rotary cutter head of a rock boring machine; first and second, axially spaced, anTi-friction bearing means rotatably supporting said cutting wheel on said frame, each of said anti-friction bearing means including an outer bearing race nonrotatably secured to said cutter wheel and an inner bearing race nonrotatably secured relative to said frame, and a plurality of bearing elements rotatably disposed between and in engagement with said inner and outer bearing races; first seal means coacting between one end of said cutting wheel and the adjacent end of said frame for preventing passage of undesired material into said first anti-friction bearing means; and second seal means coacting between the other end of said cutting wheel and the other end of said frame for preventing passage of undesired material into said second anti-friction bearing means, said second seal means being substantially identical to said first seal means; further comprising the improvement wherein each said seal means includes a nonrotatable seal ring mounted on said frame and having an annular portion of ceramic material secured thereto and defining a transverse ceramic seal face, the adjacent outer race of said anti-friction bearing means having a transverse metallic seal face formed on one axial end thereof, spring means coacting between said frame and said nonrotatable seal ring for axially urging the ceramic seal face of said nonrotatable seal ring into relative rotatable sliding engagement with the metallic seal face formed on said outer bearing race, said nonrotatable seal ring at the end thereof opposite the ceramic seal face having a tapered external configuration, a plate-like retainer disposed in engagement with said nonrotatable seal ring and having an annular tapered flange positioned in engagement with the tapered external periphery of the nonrotatable seal ring, said frame having an axially extending flange portion disposed in surrounding relationship to the tapered flange on said retainer, a resilient cushioning ring disposed between and snugly engaged with said flange portion of said frame and said tapered flange of said retainer, and said spring means including a plurality of coil springs disposed in a circular pattern and positioned axially between said retainer and said frame, said coil springs at one end thereof being disposed within recesses formed in said frame.