Patent ID: 7598634

Claim:
A fan motor comprising: a drive motor unit that includes a housing, which has a tubular portion and a bottom portion, wherein the bottom portion is provided at one axial end of the tubular portion and includes at least one cooling hole that axially penetrates through the bottom portion; and a fan that includes a fan boss, which is integrally rotatably connected to the housing and is driven by the drive motor unit, wherein: the fan boss has a tubular portion and a bottom portion; the bottom portion of the fan boss is provided at one axial end of the tubular portion of the fan boss and is axially opposed to the bottom portion of the housing while defining an axial space between the bottom portion of the fan boss and the bottom portion of the housing; a plurality of blades is provided to an outer surface of the tubular portion of the fan boss; a plurality of fins radially inwardly extends from an inner peripheral surface of the tubular portion of the fan boss and axially extends from an inner surface of the bottom portion of the fan boss at least into an interior of a corresponding one of the at least one cooling hole of the bottom portion of the housing through the axial space to form an auxiliary fin, which defines an air guide passage in the cooling hole on a forward side of the auxiliary fin in a rotational direction of the fan boss to create a cooling air flow from an interior of the housing toward an outside of the housing through the air guide passage upon rotation of the fan boss.