Vehicle seat blower unit with a motor mounted within a scroll housing and a cooling motor attachment bracket

A blower unit, adapted to be mounted in a flat space between a seat and a floor of a vehicle for blowing air from a seat surface of the seat, the blower unit comprising:

• a unit case for defining therein a scroll air passage, the unit case having a suction port on a first end surface facing the floor from which air is sucked to be blown toward the seat surface through the scroll air passage;
• a centrifugal fan rotating in the unit case around an axis to blow air sucked from the suction port radially outside in the air passage;
• a motor for rotating and driving the fan;
• a motor drive circuit for controlling a rotation speed of the motor, the motor drive circuit having a heat-generating member which generates heat when being operated;
• and
• a motor attachment bracket for attaching the motor to the unit case, the motor attachment bracket extending in a radial direction of the motor along a second end surface of the unit case outside the unit case, the second end surface being opposite to the first end surface, wherein:
• the second end surface of the unit case has a through hole through which the motor and the motor driving circuit are attached into the unit case;
• the heat-generating member of the motor drive circuit is disposed to contact the motor attachment bracket;
• the fan is a centrifugal fan having a plurality blades around an axial direction of the centrifugal fan, the centrifugal fan being disposed such that air sucked in the axial direction is blown toward a radial outside;
• the unit case includes a scroll casing for accommodating the centrifugal fan, the scroll casing having a nose portion from which a scroll shape of the scroll casing starts;
• the centrifugal fan has a fan height (H) in the axial direction, and a ratio (H/D) of the fan height to a fan diameter (D) of the centrifugal fan is equal to or lower than 0.5;
• the centrifugal fan is disposed in the scroll casing to have a dimension between the centrifugal fan and the nose portion of the scroll casing in a radial direction, the dimension being equal to or larger than 0.08 times of the fan diameter (D);
• the scroll casing has a suction port from which air is sucked in the axial direction, and a protrusion provided along an entire radial outer peripheral side of the centrifugal fan to protrude toward the centrifugal fan;
• and
• the protrusion has a protrusion end at a position corresponding to an end portion of the blades of the centrifugal fan.