Turbocharger housing construction for marine turbocharger and device for turbocharging a marine engine

In a turbocharger for marine engines of the type including a compressor housing, an impeller in the compressor housing, a turbine housing, a turbine wheel in the turbine housing, a drive shaft connecting the turbine wheel and impeller, the improvement of a fluid shielding manifold structure integral with the turbine housing, said turbine housing defining a toroidal passage for exhaust gases, an inlet to the toroidal passage from the engine at the outer toroid surface, an outlet from the inner toroid surface to the center passage in the housing, the center passage including the turbine wheel, a second separate substantially toroidal passage concentric with the first passage positioned radially outward from the first passage, said second passage being separated from the first passage by a wall and its opposite ends adjacent the first toroidal passage exhaust inlet to define a fluid flow path substantially surrounding the first passage, said second passage also including a cooling fluid inlet at one end and a cooling fluid outlet at the other end for connection with the fluid cooling system of the marine engine, said second passage defining an L-shaped cross-section and said first passage defining a generally rectangular cross-section bounded on only two sides by the second passage to shield the first passage, the turbine housing being attached to the compressor housing at an unshielded side of the compressor housing.