Patent ID: 8579602

Claim:
An exhaust fan ( 20 ) for exhausting an exhaust fluid, comprising: an intake duct ( 34 ) for the exhaust fluid; an annular exhaust duct ( 24 ) having an annular exhaust passage for the exhaust fluid between an inner housing ( 25 ) and an outer housing ( 27 ), the inner housing ( 25 ) extending between an apertured partition plate ( 48 ) and a spaced away other end, the inner housing ( 25 ) defining a core ( 42 ), the apertured partition plate ( 48 ) having an enlarged central aperture; a fan wheel ( 22 ) disposed between the intake and exhaust ducts ( 34 , 24 ), the fan wheel ( 22 ) having a base plate ( 62 ) closely adjacent to the partition plate ( 48 ) on the opposite side from the core ( 42 ); a motor mounting bracket ( 66 ) mounted inside the inner housing ( 25 ); a drive motor ( 30 ) disposed in the core ( 42 ) of the inner housing ( 25 ) and removably mounted to the mounting bracket ( 66 ) therefor, said drive motor ( 30 ) turning a drive hub ( 54 ) that occupies the central aperture of the partition plate ( 48 ); mechanical connections ( 64 ) for removably mounting the drive hub ( 54 ) to the base plate ( 62 ) of the fan wheel ( 22 ); at least one window frame ( 38 ) defining a service window and extending between the inner and outer housings ( 25 , 27 ) which thereby allows a worker access into the core ( 42 ) and thus to the drive motor ( 30 ), the drive motor mounting bracket ( 66 ), the hub-fastening connections ( 64 ) and the partition plate ( 48 ) without opening or accessing into either of the ducts ( 34 , 24 ) for the exhaust fluid, whereby the worker is isolated from the ducts and the exhaust fluid when removing the drive motor; temporary locking connections ( 56 ) actuated from inside the core ( 42 ) of the inner housing ( 25 ) by a worker reaching through the window frame ( 38 ) of the service window, said temporary locking connections temporarily locking the base plate ( 62 ) of the fan wheel ( 22 ) to partition plate ( 48 ) of the exhaust duct ( 24 ) whereby the drive motor ( 30 ) can be de-coupled from the base plate ( 62 ) of the fan wheel ( 22 ) and the drive motor mounting bracket ( 66 ) and removed while the partition plate ( 48 ) carries the weight of the fan wheel ( 22 ).