Bellows seal

Claim 1

In a mechanical seal construction, which can be utilized under conditions of extremely high or extremely low temperatures, particularly above 600* F. and below -100* F., and designed for use between a wall and a shaft extending therethrough and rotatable relative thereto, said mechanical seal construction having a pair of seal elements having mutually contacting sealing faces, one seal element being fixed with respect to said wall and the other seal element being capable of rotation in response to rotation of said shaft, the improvement comprising: annular collar means surrounding and fixedly secured to said shaft, said collar means including an annular recess disposed directly adjacent and in surrounding relationship to said shaft; elongated flexible bellows means extending between and sealingly connected to said other seal element and said collar means for supporting said other seal element and permitting same to move relative to said collar means, said bellows means including a plurality of metal plates alternately having their inner and outer peripheries sealingly connected; sealing means coacting between said collar means and said shaft for creating a sealed relationship therebetween, said sealing means including an annular ringlike sealing member constructed of multilayer graphite material and disposed within said annular recess; and said collar means including means for causing both axial and radial compression of said graphite sealing member, said lastmentioned means including a substantially conical wall disposed in surrounding relationship to and partially defining said annular recess, said conical wall being slightly tapered relative to the axis of said shaft for causing said sealing member to be radially compressed into sealing engagement with the periphery of said shaft.