Axial-flow type fan having an air inlet blade structure tipped with leading corners

Abstract

An axial-flow type fan includes a fan housing consisting of an air-boosting inlet, an air outlet and an air channel, and a fan wheel consisting of a hub and fan blades arranged about a rotary axis of the hub. Each of the fan blades has a tipped leading corner to constitute an air inlet blade structure which forms a topmost portion in a longitudinal direction and a forefront portion in a rotational direction. The tipped leading corners are situated in the air-boosting inlet of the fan housing while the air channel accommodates the fan wheel. When the fan wheel is rotated, the tipped leading corners of the fan blades are able to eliminate air turbulence and air noise in the air-boosting inlet of the fan housing.

1 . An axial-flow type fan, comprising: 
 a fan housing including an air inlet side and an air outlet side at its either side;    an air-boosting inlet provided on the air inlet side of the fan housing;    an air channel connecting between the air-boosting inlet and the air outlet side;    a fan wheel accommodating in the channel and including a hub;    a plurality of fan blades arranged about a rotary axis of the fan wheel and tilted on the hub, and each of the fan blades having an inlet bottom point connecting to the hub of the fan wheel; and    a plurality of tipped leading corners, each provided on the fan blade to form a topmost portion in a longitudinal direction of the fan housing and a forefront portion in a rotational direction of the fan wheel, the tipped leading corner situated in the air-boosting inlet and including a curved leading edge connecting between an inlet leading corner point of the tipped leading corner and the inlet bottom point;    wherein when the fan wheel is rotated, the tipped leading corners of the blades are able to eliminate air turbulence and air noise in the air-boosting inlet of the fan housing.    
   
   
       2 . The axial-flow type fan as defined in  claim 1 , wherein the air-boosting inlet forms with an annular tapered surface along the longitudinal direction of the fan housing.  
   
   
       3 . The axial-flow type fan as defined in  claim 1 , wherein each of the fan blades further includes an outlet bottom point so that the fan blade tilts between the inlet bottom point and the outlet bottom point of an outer circumference of the hub.  
   
   
       4 . The axial-flow type fan as defined in  claim 3 , wherein the each of the fan blades further includes a ridge protruded on a leeward surface of the fan blade connecting between an inlet leading corner point of the tipped leading corner and the outlet bottom point, thereby the ridge stabilizing airflow.