Patent ID: 7987868

Claim:
An exhaust gas valve assembly comprising: a housing having an intake port, an exhaust port, and a substantially cylindrical cavity defined therein, the cavity having a first end and an opposite second end, the housing defining a housing surface at the first end of the cavity, the housing surface surrounding the cavity and facing away from the second end of the cavity; a valve seat having a portion thereof disposed within the cavity, said valve seat having a first axial end secured to the housing and a second axial end, the second axial end being disposed within, but decoupled a distance from, the housing, said second axial end positioned between the intake and exhaust ports, the second axial end defining an opening in fluid communication with an interior of the valve seat, a side wall of the valve seat defining an aperture also in fluid communication with the interior of the valve seat, the valve seat defining a seat surface, the intake port and the exhaust port being in fluid communication with the interior of the valve seat via the opening and aperture in the valve seat, wherein the first axial end of the valve seat defines a flange having an engagement surface that lies against the housing surface so as to axially locate the valve seat relative to the housing; a piston received within the interior of the valve seat, one end of said piston defining a piston surface engageable with the seat surface of the valve seat so as to prevent flow between the opening and the aperture of the valve seat, said piston configured to reciprocate axially within the valve seat so as to cause the piston surface to engage and disengage the seat surface and thereby regulate exhaust gas flow between the intake port and the exhaust port; and a seal disposed between the housing and the valve seat proximate the second axial end of the valve seat, said seal closing the decoupled distance between the housing and valve seat.