Counter-rotating axial-flow fan

Abstract

A counter rotating axial flow fan that reduces vibration generation over a wide rotational speed range. A disk-shaped cushioning member is disposed between a circular plate portion of a first support frame main body half portion and a circular plate portion of a second support frame main body half portion. The cushioning member is compressed, with hook portions forming a plurality of engaging portions and hole portions forming a plurality of engaged portions completely engaged with each other.

1 . A counter-rotating axial flow fan comprising:
 a housing including a housing main body having defined therein an air channel having a suction port at one end in an axial direction and a discharge port at the other end in the axial direction, and a motor support frame disposed at a center portion of the air channel;   a first impeller disposed in a first space defined in the housing between the motor support frame and the suction port and including a plurality of blades;   a first motor including a first rotary shaft to which the first impeller is fixed to rotate the first impeller in a first rotational direction in the first space;   a second impeller disposed in a second space defined in the housing between the motor support frame and the discharge port and including a plurality of blades; and   a second motor including a second rotary shaft to which the second impeller is fixed to rotate the second impeller in a second rotational direction opposite the first rotational direction in the second space,   the motor support frame including a support frame main body located at the center portion of the air channel and a plurality of webs disposed between the support frame main body and the housing main body at predetermined intervals in a circumferential direction of the rotary shafts to couple the support frame main body and the housing main body,   the housing including a first split housing unit and a second split housing unit coupled to each other by a mechanical coupling structure,   the first split housing unit including a first housing main body half portion including a first cylindrical air channel half portion having the suction port at one end and having defined therein a main portion of the first space, and a first support frame half portion which is one of two pieces obtained by splitting the motor support frame along a split plane extending in a radial direction perpendicular to the axial direction,   the second split housing unit including a second housing main body half portion including a second cylindrical air channel half portion having the discharge port at one end and having defined therein a main portion of the second space, and a second support frame half portion which is the other of the two pieces obtained by splitting the motor support frame along the split plane,   the coupling structure including a plurality of engaging portions integrally formed with the first housing main body half portion of the first split housing unit and disposed at intervals in the circumferential direction, and a plurality of engaged portions integrally formed with the second housing main body half portion of the second split housing unit and disposed at intervals in the circumferential direction to be engaged with the plurality of engaging portions,   the coupling structure and the first and second split housing units being configured such that an opposed surface of the first support frame half portion and an opposed surface of the second support frame half portion entirely contact each other when the plurality of engaging portions and the plurality of engaged portions are completely engaged with each other,   the first support frame half portion including a first support frame main body half portion to which the first motor is fixed and a plurality of first web half portions, and   the second support frame half portion including a second support frame main body half portion to which the second motor is fixed and a plurality of second web half portions,   wherein a soft cushioning member with a plurality of independent air bubbles dispersed therein is disposed between the first support frame main body half portion and the second support frame main body half portion, the cushioning member being compressed when the plurality of engaging portions and the plurality of engaged portions are completely engaged with each other.   
   
   
       2 . A counter-rotating axial flow fan comprising:
 a housing including a housing main body having defined therein an air channel having a suction port at one end in an axial direction and a discharge port at the other end in the axial direction, and a motor support frame disposed at a center portion of the air channel;   a first impeller disposed in a first space defined in the housing between the motor support frame and the suction port and including a plurality of blades;   a first motor including a first rotary shaft to which the first impeller is fixed to rotate the first impeller in a first rotational direction in the first space;   a second impeller disposed in a second space defined in the housing between the motor support frame and the discharge port and including a plurality of blades; and   a second motor including a second rotary shaft to which the second impeller is fixed to rotate the second impeller in a second rotational direction opposite the first rotational direction in the second space,   the motor support frame including a support frame main body located at the center portion of the air channel and a plurality of webs disposed between the support frame main body and the housing main body at predetermined intervals in a circumferential direction of the rotary shafts to couple the support frame main body and the housing main body,   the housing including a first split housing unit and a second split housing unit coupled to each other by a mechanical coupling structure,   the first split housing unit including a first housing main body half portion including a first cylindrical air channel half portion having the suction port at one end and having defined therein a main portion of the first space, and a first support frame half portion which is one of two pieces obtained by splitting the motor support frame along a split plane extending in a radial direction perpendicular to the axial direction,   the second split housing unit including a second housing main body half portion including a second cylindrical air channel half portion having the discharge port at one end and having defined therein a main portion of the second space, and a second support frame half portion which is the other of the two pieces obtained by splitting the motor support frame along the split plane,   the coupling structure including a plurality of engaging portions integrally formed with the first housing main body half portion of the first split housing unit and disposed at intervals in the circumferential direction, and a plurality of engaged portions integrally formed with the second housing main body half portion of the second split housing unit and disposed at intervals in the circumferential direction to be engaged with the plurality of engaging portions, and   the coupling structure and the first and second split housing units being configured such that opposed surfaces of the first and second support frame half portions entirely contact each other when the plurality of engaging portions and the plurality of engaged portions are completely engaged with each other,   wherein a soft cushioning member with a plurality of independent air bubbles dispersed therein is disposed between the first support frame half portion and the second support frame half portion, the cushioning member being compressed when the plurality of engaging portions and the plurality of engaged portions are completely engaged with each other.   
   
   
       3 . The counter-rotating axial flow fan according to  claim 2 , wherein
 the first support frame half portion includes a first support frame main body half portion to which the first motor is fixed,   the second support frame half portion includes a second support frame main body half portion to which the second motor is fixed, and   the cushioning member is disposed between the first support frame main body half portion and the second support frame main body half portion.   
   
   
       4 . The counter-rotating axial flow fan according to  claim 1 , wherein
 the first and second split housing units are formed from a synthetic resin material.   
   
   
       5 . The counter-rotating axial flow fan according to  claim 1 , wherein
 the first and second split housing units are formed from aluminum.   
   
   
       6 . The counter-rotating axial flow fan according to  claim 1 , wherein
 the cushioning member is an acrylic foam sheet with a thickness of not less than 0.4 mm and not more than 0.8 mm.   
   
   
       7 . The counter-rotating axial flow fan according to  claim 2 , wherein
 the first and second split housing units are formed from a synthetic resin material.   
   
   
       8 . The counter-rotating axial flow fan according to  claim 2 , wherein
 the first and second split housing units are formed from aluminum.   
   
   
       9 . The counter-rotating axial flow fan according to  claim 2 , wherein
 the cushioning member is an acrylic foam sheet with a thickness of not less than 0.4 mm and not more than 0.8 mm.