Fan assembly having an air directing member to cool a motor

A fan assembly to be driven by a brushless motor, the motor including a rotatable rotor and a stator which houses a heat sink portion for cooling the motor, the rotor having a plurality of radially extending rib members defining a corresponding plurality of cooling air openings which communicate with a cooling air path within the motor, the fan assembly comprising:

• a) a hub having a base plate adapted to be torsionally fixed to the rotor for rotation therewith, said hub further having a cylindrically shaped flange member extending proximally from said base plate in an axial direction, and configured and dimensioned to circumferentially encircle at least a portion of the rotor in adjacent contacting relation therewith, said portion of the rotor including said cooling air openings;
• b) a plurality of fan blades extending radially outwardly from said cylindrically shaped flange member for rotation with said base plate and the rotor, said fan blades being configured and oriented such that during rotation thereof, the fan blades create an atmospheric pressure region on one side thereof which is greater that the atmospheric pressure region on the other side of the fan blades;
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• c) a cooling air directing plate member torsionally fixed to the rotor and disposed generally adjacent to said portion of said rotor so as to define a radially extending cooling air directing space which communicates with the cooling air openings in the rotor whereby cooling air is directed from said region of greater pressure through the cooling air path within the motor and past the heat sink portion, and through the cooling air openings in the rotor so as to direct air to said region of lower pressure.

A fan assembly to be driven by a brushless motor, the motor including a rotatably driven rotor, a housing having cooling air openings which permit cooling air to pass through a cooling air path within the motor, and a heat sink portion within the housing for cooling the motor, the rotor having a plurality of radially extending rib members defining a corresponding plurality of openings which communicate with the cooling air path within the motor, which comprises:

• a) a hub having a base plate adapted to be attached to the rotor for rotation therewith, said hub further having a first circumferential flange member extending proximally from said base plate in an axial direction, and configured and dimensioned to circumferentially encircle at least a portion of the rotor in adjacent contacting relation therewith;
• b) a plurality of torque studs configured and positioned to torsionally fix said base plate to the rotor;
• c) a plurality of fan blades attached to said circumferential flange member and extending radially outwardly therefrom for rotation with said hub and the rotor, said fan blades being configured and oriented such that during rotation, the atmospheric pressure downstream of said fan blades is greater than the atmospheric pressure upstream of said fan blades;
• d) a cooling air directing plate positioned axially upstream of said hub to define an air directing space with the rotor, said air directing space communicating the lower pressure region with the higher pressure region through a cooling air path in the motor and said hub openings to cool the motor;
• e) a second flange member connected to said cooling air directing plate and extending proximally therefrom in an axial direction, said second flange member being spaced radially outwardly from said first flange member and concentric therewith to define an annular space which communicates with said cooling air directing space defined by said cooling air directing plate and the rotor, said fan blades extending through said second flange member and connected thereto to strengthen said first and second flange members;
• and
• f) a releasable fastener to connect said cooling air directing plate to said second flange member.