Patent ID: 7168920

Claim:
A fan case base, comprising: a square frame with an air inlet side and an air outlet side, and having a hollow space between the air inlet side and the air outlet side; a base support, being disposed at the center of the air outlet side and being joined to an inner wall of the hollow space; a fan wheel with an outer lateral side, being received in the hollow space, having a hub being joined to the base support and the outer lateral side being disposed next to the air inlet side; and an engaging part, being disposed at four corners of the frame respectively; characterized in that the outer lateral side of the fan wheel slightly extends outward the air inlet side of the frame and the engaging part slightly extends outward from the air inlet side of the frame in a way of the engaging part provides a first height greater than a second height between the air inlet side and the outer lateral side of the fan wheel such that a clearance is defined by the outer lateral side of the fan wheel, the engaging part and the air inlet side of the frame for air flow being guided through the clearance.