Electrically isolated coolant manifold with recessed apertures for emi reduction

Abstract

A power electronics chassis ( ) for electric vehicles and other applications that use liquid coolant to cool power electronic devices ( ) contained within the chassis. The chassis ( ) includes an electrically conductive housing ( ) and an electrically non-conductive manifold ( ) that permits coolant flow into and out of the housing. The housing ( ) has at least one wall ( ) that includes an outer surface ( ) and a pair of recessed apertures ( ), each of which provide access to an interior region ( ) of the housing ( ) via a passageway ( ). The manifold ( ) has an inlet ( ) and an outlet ( ), each of which has a connecting tube ( ) that extends through one of the passageways ( ). Each passageway ( ) is defined by an axial wall ( ) of the housing ( ) that extends towards the interior region ( ) from the outer surface ( ) to its respective aperture. The apertures ( ) are each formed by an annular wall ( ) that extends radially inward from its associated axial wall ( ) at the interior end of its passageway. The outer diameter of the connecting tubes ( ) are equal to the diameter of their respective apertures ( ). Thus, each tube ( ) is in contact with its aperture ( ) and is separated from its adjacent axial wall ( ) by an annular gap ( ). This configuration provides electrical isolation of the coolant from the chassis ( ) in a manner that significantly reduces the radiated emissions at the apertures ( ).