Patent ID: 7341257

Claim:
A shaft seal assembly, comprising: a carrier body having an axially outer-most surface and a circumferentially extending annular surface providing an opening with a pocket extending radially outwardly from said opening into said axially outer-most surface and having mounting features to enable said carrier body to be mounted on a housing about an opening of the housing through which a rotatable shaft extends; an annular dynamic seal mounted on said carrier body extending-radially inwardly of said opening of said carrier body; a sleeve member mountable on and rotatable with the shaft relative to said carrier body and said dynamic seal; a multi-pole encoder ring secured to said sleeve and having a radially outwardly facing signal surface; a magneto-resistive sensor mounted on said carrier body in said pocket and having a radially inwardly facing sensor surface arranged substantially flush with said annular surface of said carrier body and exposed in unobstructed open communication with said radially outwardly facing signal surface of said encoder ring and having an axially outer-most surface arranged substantially flush with said axially outer-most surface of said carrier body on an air side of said shaft seal assembly; and wherein a labyrinth seal is provided having a radially facing inner surface with a constant first diameter formed at least in part by said signal surface of said encoder ring, and a radially facing outer surface having a constant second diameter that is greater than said first diameter, said outer surface being formed at least in part by said sensor surface and said annular surface of said carrier body, said labyrinth seal having a substantially continuous circumferential width across said radially facing inner and outer surfaces and being in open communication with the air side of said shaft seal assembly.