Patent ID: 7121551
Filing Date: 2006-10-17
Classification: F04D,F16J

Abstract:
1. A set of bushing members providing bushing arrangements for protecting a seal cavity of rotary fluid equipment, which cavity is defined in part by a rotatable shaft having an outer cylindrical surface, a surrounding housing having an inner cylindrical surface spaced radially outwardly of said shaft, an entrance zone, and an end remote from said entrance zone, said cavity being adapted to receive conventional packing material therein or to have a mechanical seal positioned at said remote end, said set of bushing members comprising: a) primary and secondary generally cylindrical bushing members adapted for positioning in said cavity, each such bushing member having an outer cylindrical surface for slidably engaging said housing inner surface, and an inner cylindrical bore of a diameter greater than the diameter of said shaft so as to define an annular gap between such bore and said shaft outer surface; b) said primary bushing member having proximal and distal annular end faces; c) the inner bore of said primary bushing member including proximal and distal end sections of generally uniform diameter opening from an interior of said primary bushing member to said proximal and distal end faces respectively, a section of increasing diameter extending into said interior from a proximal end of said distal section, and a section of decreasing diameter extending from a proximal end of said section of increasing diameter to a distal end of said proximal section, at least said section of decreasing diameter defining a spiral groove opening towards said section of increasing diameter and having a hand in the seine direction of rotation as said shaft; d) said secondary bushing member having a proximal end face adapted for mating abutment against said distal end face of said primary bushing member; and e) said inner bore of said secondary bushing member including a proximal bore section of generally uniform diameter opening from the interior of said secondary bushing member to said secondary bushing member proximal end face, and a distal bore section of increasing diameter leading from a distal end of said proximal bore section to a distal end of said secondary bushing member adjacent the outer cylindrical surface thereof, at least said secondary bushing member distal bore section defining a spiral groove opening towards said secondary bushing distal end and having a hand in the same direction of rotation as said shaft.