Fan biasing transmission mechanism

A fan biasing transmission mechanism, comprising:

• a housing having a first mounting chamber, a second mounting chamber and a third mounting chamber disposed intermediate said first and second mounting chambers;
• a control rod mounted in said first mounting chamber, said control rod having a driving gear wheel and a driven gear mounted thereon;
• a worm coupled to a motor and meshed with said driving gear wheel;
• a follower gear wheel pivotally mounted in said second mounting chamber;
• a link coupled with said follower gear wheel;
• two speed-changing transmission gears pivotally mounted on a common shaft in a stepped manner in said third mounting chamber and respectively meshed with said driven gear and said follower gear wheel, a lower end of said shaft being supported in said third mounting chamber;
• a locating plate bridging between said first and third mounting chambers and having an opening for receiving an upper end of said shaft therein for supporting said two speed-changing transmission gears in respective meshing engagement with said driven gear and said follower gear wheel;
• and
• a cap forming a closure for said housing, said cap having a cavity for receiving an upper end of said control rod therein to provide support thereof.