A system includes a gearbox having an external surface; a fan or impeller constructed to generate a first cooling airflow when rotated; a shroud operative to guide and discharge the first cooling airflow over the external surface and cool the gearbox, wherein at least a portion of the shroud is spaced apart from the gearbox and disposed radially outward of the external surface; and a flow entrainment structure coupled to the gearbox and/or the shroud, wherein the flow entrainment structure is constructed to entrain a second cooling airflow and combine the second cooling airflow with the first cooling airflow to form a combined cooling airflow directed across the external surface to cool the gearbox.

A system includes a machine having an external surface and a shaft extending from a first side of the machine; a cooling airflow generator mounted on the shaft and operative to generate a cooling airflow for cooling the machine; a flow guide structure constructed to receive the cooling airflow from the cooling airflow generator and to direct the cooling airflow received from the cooling airflow generator across the external surface; and a scavenge scoop spaced apart from the flow guide structure and disposed at a second side of the machine opposite the first side, wherein the external surface is disposed between the scavenge scoop and the flow guide structure, and wherein the scavenge scoop is constructed to collect a portion of the cooling airflow generated by the cooling airflow generator and direct the a portion of the cooling airflow across a portion of the second side of the machine.

A system includes a gearbox having an external surface; a fan or impeller constructed to generate a first cooling airflow when rotated; a shroud operative to guide and discharge the first cooling airflow over the external surface and cool the gearbox, wherein at least a portion of the shroud is spaced apart from the gearbox and disposed radially outward of the external surface; and a flow entrainment structure coupled to the gearbox and/or the shroud, wherein the flow entrainment structure is constructed to entrain a second cooling airflow and combine the second cooling airflow with the first cooling airflow to form a combined cooling airflow directed across the external surface to cool the gearbox.

A system includes a machine having an external surface and a shaft extending from a first side of the machine; a cooling airflow generator mounted on the shaft and operative to generate a cooling airflow for cooling the machine; a flow guide structure constructed to receive the cooling airflow from the cooling airflow generator and to direct the cooling airflow received from the cooling airflow generator across the external surface; and a scavenge scoop spaced apart from the flow guide structure and disposed at a second side of the machine opposite the first side, wherein the external surface is disposed between the scavenge scoop and the flow guide structure, and wherein the scavenge scoop is constructed to collect a portion of the cooling airflow generated by the cooling airflow generator and direct the a portion of the cooling airflow across a portion of the second side of the machine.

A transmission having improved heat dissipation components is disclosed. The transmission includes a housing having housing walls defining an internal chamber and a rotatable input shaft extending through one of the housing walls into the internal chamber. Power transmission components are disposed in the internal chamber and rotatably driven by the input shaft. An output shaft extends through one of the housing walls from the internal chamber and is rotatably driven by the power transmission components. A lubricating fluid is disposed in the internal chamber and lubricates the power transmission components. A cooling shroud surrounds the housing and includes a cooling passageway in fluid communication with the internal chamber. The lubricating fluid flows out of the internal chamber into the cooling passageway, through the cooling passageway, and back into the internal chamber.

A vehicle electrical power system includes a variable voltage converter. The variable voltage converter includes an inductor assembly having a housing that defines a chamber containing dielectric fluid. An inductor is disposed within the chamber and is in contact with the fluid. The power system also includes a pump configured to circulate the dielectric fluid to cool the inductor.