Abstract: A self-propelled windrower includes an engine compartment containing an engine-driven fan for pulling cooling air through a screen covering a circular air inlet leading into the compartment. The fan also is coupled for creating a suction in an air duct extending diametrically across the air inlet, the duct in turn being coupled to the center of a channel-like vacuum wand mounted for sweeping the exterior of the screen and removing airborne debris collected by the screen. Provided for rotatably supporting a drive shaft for the wand is a bearing support member including a cylindrical portion having an end fixed to a mounting plate secured to the air duct, the cylindrical portion having an interior end section receiving an outer race of a roller bearing having an inner race receiving and being fixed to the wand drive shaft. An electric drive motor is located within said compartment and mounted to said air duct at a side thereof remote from said screen.