Blower wheel with axial inlet for ventilation

A blower wheel for providing ventilating air into a housing of an electric machine, which comprises:

• a generally dome-shaped hub with a center portion and a generally circular outer portion, the center portion being displaced upwardly from the outer portion to form a substantially continuous outer surface, the center portion defining a longitudinal axis and having a ventilation aperture extending therethrough in general alignment with the longitudinal axis and being dimensioned to permit air to pass through the center portion;
• a first plurality of blades extending upwardly from the outer portion of the hub;
• a second plurality of blades extending downwardly from the center portion of the hub;
• a third plurality of blades extending downwardly from the outer portion of the hub;
• and
• mounting means for mounting the hub to the housing;
• wherein air is communicated through the ventilation aperture in the center portion of the hub, the first plurality of blades being adapted to guide air at least partially toward the outer surface of the hub and at least partially into the ventilation aperture, the second plurality of blades being adapted to transmit air into the housing and the third plurality of blades being adapted to transmit air from the housing.

An apparatus for providing ventilating air into a housing of an electric motor, which comprises:

• a hub mountable to the housing of the electric motor, the hub including a center portion and an outer portion, the center portion having a generally dome-shaped configuration and defining an inner chamber, and a ventilation aperture in general alignment with a longitudinal axis of the hub, the ventilation aperture dimensioned to permit air to pass into the inner chamber;
• a first plurality of blades extending from the outer portion of the hub in a first axial direction, the first plurality of blades dimensioned to direct air at least through the ventilation aperture;
• a second plurality of blades extending within the inner chamber of the center portion of the hub in a second axial direction, the second axial direction being different than the first axial direction, the second plurality of blades dimensioned to direct air at least from the ventilation aperture to the inner chamber of the hub;
• and
• a third plurality of blades extending from the outer portion of the hub in the second axial direction, the third plurality of blades dimensioned to direct air from the inner chamber to the housing of the electric motor.

In combination:

• an electric motor including a rotor mounted for rotational movement, the rotor including a rotor housing having a ventilation opening therethrough;
• and
• a blower wheel mounted to the rotor for providing ventilating air to the electric motor, the blower wheel including:
• a hub having a center portion and an outer portion, the center portion defining a longitudinal axis and having a ventilation aperture extending therethrough in general alignment with the longitudinal axis and being dimensioned to permit air to pass through the center portion;
• a first set of blades extending in a first axial direction from the outer portion of the hub and being dimensioned to direct air at least through the ventilation aperture;
• and
• a second set of blades extending in a second axial direction, different from the first axial direction, from the outer portion of the hub and being dimensioned to direct air through the ventilation opening of the rotor housing.