Patent ID: 8760016

Claim:
An electric machine comprising: a casing have a first end plate and a second end plate, the first end plate having an air inlet and the second endplate having an air outlet; an outer rotor positioned inside the casing; a stator positioned inside the outer rotor; a hub positioned inside the stator; a rotor endplate coupled to an end of the outer rotor, the rotor end plate including a rotor end plate opening for allowing air to pass through the rotor endplate; a fan positioned within the casing, the fan drawing air from the air inlet and exhausting air out the air outlet; a shaft positioned inside the stator, the shaft coupled to the rotor end plate and coupled to the fan to rotate the fan and the rotor endplate simultaneously; a retaining ring coupled to an end of the hub, the retaining ring including a retaining ring opening for allowing air to pass through the retaining ring; and fins on the inside of the hub, the fins extending from an inside surface of the hub radially inwardly towards the shaft; wherein the hub includes a hub opening formed in a wall of the hub for allowing air to pass through the hub wall, the air inlet, hub opening, retaining ring opening, rotor end plate opening and air outlet defining an air path through the electric machine.