Axial Fan

Abstract

An axial fan is provided which has a high degree of freedom of design of a condition of gas to be discharged. An axial fan 1 of the present disclosure comprises a discharge port; a rotation axis; an impeller 23 ; and a casing 30 including a side wall 31 part that encloses the impeller 23 , wherein the side wall part 31 includes a plurality of inner face parts 37 a 1 in a circumferential direction on the discharge port 2 side, and an inner face part angle is an angle of the inner face part 37 a 1 with respect to the rotation axis, and the inner face part angle on an outwardly spreading side with respect to the rotation axis is a positive angle, and the inner face part angles are greater than 0°, and the two inner face parts adjacent to each other have different inner face part angles.

What is claimed is: 
     
         1 . An axial fan comprising:
 a discharge port;   a rotation axis;   an impeller; and   a casing including a side wall part that encloses the impeller,   wherein the side wall part includes a plurality of inner face parts in a circumferential direction on the discharge port side, and   an inner face part angle is an angle of the inner face part with respect to the rotation axis, and   the inner face part angle on an outwardly spreading side with respect to the rotation axis is a positive angle, and   the inner face part angles are greater than 0°, and   the two inner face parts adjacent to each other have different inner face part angles.   
     
     
         2 . The axial fan according to  claim 1 , wherein the inner face parts are arranged to be lined in a circumferential direction. 
     
     
         3 . The axial fan according to  claim 1 , wherein the number of the inner face parts is two. 
     
     
         4 . The axial fan according to  claim 1 , wherein the number of the inner face parts is three or more. 
     
     
         5 . The axial fan according to  claim 4 , wherein the number of the inner face parts is an even number, and
 two of the inner face parts facing in a radial direction include the same inner face part angle.   
     
     
         6 . The axial fan according to  claim 1 , wherein the casing includes an opening part as the discharge port, and
 the number of the inner face parts is two, and   one of the inner face parts has a range less than half of an inner peripheral end part provided in the side wall part on the opening part side, with respect to an entire circumference of the inner peripheral end part in the circumferential direction.   
     
     
         7 . The axial fan according to  claim 1 , wherein a height of the inner face part is equal to or less than ⅓ of a height of the side wall part in a rotation axis direction.