Patent ID: 8794299

Claim:
An exhaust gas cooler for use in an engine system including a combustion engine and a cooling system, the exhaust gas cooler configured to cool an exhaust gas flow of the combustion engine, the exhaust gas cooler comprising: a first pass; a second pass; an inlet/outlet manifold to direct the exhaust gas flow to the first pass and from the second pass; a turning manifold to direct the exhaust gas flow from the first pass to the second pass; a first exhaust gas core including a first plurality of tubes defining the first pass and a first transition piece including a first header plate that receives the first plurality of tubes and a first elongated extension that extends from the first header plate; a second exhaust gas core including a second plurality of tubes defining the second pass and a second transition piece including a second header plate that receives the second plurality of tubes and a second elongated extension that extends from the second header plate; a coolant housing including a first end fixed to the inlet/outlet manifold and a second end fixed to the turning manifold, the coolant housing surrounds the first and second exhaust gas cores to direct at least one coolant flow past the first and second exhaust gas cores, the coolant housing further including a first opening adjacent the second end and a second opening adjacent the second end, the first elongated extension extends through the first opening of the coolant housing and the second elongated extension extends through the second opening of the coolant housing; a first thermal expansion joint including a first O-ring seal disposed in the first opening to allow the first elongated extension of the first exhaust gas core to slide within the first opening thereby allowing the first exhaust gas core to expand with respect to the coolant housing; and a second thermal expansion joint including a second O-ring seal disposed in the second opening to allow the second elongated extension of the second exhaust gas core to slide within the second opening thereby allowing the second exhaust gas core to expand with respect to the coolant housing independently of the first exhaust gas core, wherein the coolant housing includes a third opening adjacent the first end of the coolant housing, the cooler further comprising a third header plate coupled to the coolant housing adjacent the first end and outside the coolant housing, wherein the first plurality of tubes each include a first end coupled to the first transition piece and a second end coupled to the third header plate, and wherein the second plurality of tubes each include a first end coupled to the second transition piece and a second end coupled to the third header plate such that the third header plate spans the first and second exhaust gas cores.