Wet pick-up vacuum unit motor bearing air seal

Claim 1

In a wet pick-up type vacuum cleaner fan unit with a cleaning working air centrifugal fan impeller mounted on a fan shaft supported in a lubricated bearing received in a central socket of a fan housing end wall, said impeller peripherally discharging to a working air outlet of the housing located adjacent to said end wall, the improvement comprising: a centrally apertured disk plate circumferentially engaged and sealed upon and spaced from the fanward inner face of the said end wall; a plurality of angularly spaced auxiliary or sealing air inlets through said wall from the exterior to an air flow space defined between the disk and end wall face; an auxiliary centrifugal fan of smaller diameter than, and in back-to-back relation with, said working fan impeller, said auxiliary fan being clamped on said shaft with its inlet eye facing the central aperture of said disk to receive auxiliary air therefrom; a shield cup received with circumferential spacing in the auxiliary fan inlet eye and having a centrally apertured flat bottom conjointly clamped with said fans on said shaft, and extending through the central aperture of the disk to define with the edge thereof a discharge outlet from said flow space into the auxiliary fan eye; whereby said shield and disk provide structural screening around said bearing socket and shaft, and said auxiliary fan, shield and disk further moving auxiliary screening and sealing air axially exterior to the socket and on out to a common discharge of said back-to-back auxiliary and working air fans to prevent foam and working air entrained detergent from approaching said bearing.