Impeller and blower

Abstract

A blower includes an impeller rotatable about a central axis and a motor driving the impeller. The impeller includes a first impeller, and a second impeller connected to the first impeller. The first impeller includes a base and first blades arranged in a circumferential direction. The base includes a cup portion of which an axially upper end is closed and a flange extending radially outward from an axially lower end of the cup portion. The second impeller includes a shroud with an annular or substantially annular shape about the central axis and axially opposes an upper surface of the flange, and second blades arranged in the circumferential direction. Each first blade protrudes axially upward from the flange. Each second blade protrudes axially downward from the shroud.

1 - 17 . (canceled) 
     
     
         18 : An impeller rotatable about a central axis extending in an axial direction, the impeller comprising:
 a first impeller; and   a second impeller connected to the first impeller; wherein   the first impeller includes:
 a base; and 
 a plurality of first blades arranged in a circumferential direction; 
   the base includes:
 a cup portion including an axially upper end that is closed; and 
 a flange extending radially outward from an axially lower end of the cup portion; 
   the second impeller includes:
 a shroud with an annular or substantially annular shape about the central axis and opposing an upper surface of the flange in an axial direction; and 
 a plurality of second blades arranged in the circumferential direction; 
   each of the first blades protrudes axially upward from the flange;   each of the second blades protrudes axially downward from the shroud; and   in the circumferential direction, at least one second blade is located between the first blades adjacent to each other.   
     
     
         19 : The impeller according to  claim 18 , wherein
 the base includes a first groove recessed axially downward;   the first groove is between the first blades adjacent to each other and extends in a direction in which the at least one second blade extends; and   an axially lower end of the at least one second blade is located in the first groove.   
     
     
         20 : The impeller according to  claim 18 , wherein
 the base includes a through-hole penetrating the base in the axial direction;   the at least one second blade includes a fixing portion extending in the axial direction; and   the fixing portion is fixed to the base through the through-hole.   
     
     
         21 : The impeller according to  20 , wherein
 a fixing portion includes a thermal deformation portion in which a portion of the fixing portion is thermally deformed; and   the thermal deformation portion is in contact with a lower surface of the base.   
     
     
         22 : The impeller according to  claim 20 , wherein
 the fixing portion includes a claw; and   the claw is hooked to a lower surface of the base.   
     
     
         23 : The impeller according to  claim 22 , wherein the claw is provided on an axially lower side of a radial end of the at least one second blade. 
     
     
         24 : The impeller according to  claim 23 , wherein the claw is provided on an axially lower side of a radially inner end of the at least one second blade. 
     
     
         25 : The impeller according to  claim 23 , wherein the claw is located radially inside of a radially inner peripheral edge of the shroud. 
     
     
         26 : The impeller according to  claim 25 , wherein when viewed in the axial direction, the claw extends from the radially inner end of the at least one second blade to the central axis side in a direction in which the at least one second blade extends. 
     
     
         27 : The impeller according to  claim 19 , wherein
 an upper surface of the claw is in contact with the lower surface of the base; and   the axially lower end of the second blade opposes a bottom surface of the first groove with a gap therebetween.   
     
     
         28 : The impeller according to  claim 23 , wherein the impeller further includes a filler inside the through-hole. 
     
     
         29 : The impeller according to  claim 28 , wherein the filler covers at least a portion of the claw outside the through-hole. 
     
     
         30 : The impeller according to  claim 18 , wherein
 the shroud includes a second groove recessed axially upward;   the second groove is provided between two of the second blades adjacent to each other and extends in a direction in which the at least one first blade extends; and   an axially upper end of the at least one first blade is located in the second groove.   
     
     
         31 : The impeller according to  claim 18 , wherein a radially inner end of the second blade is located radially outside a radially inner end of the first blade. 
     
     
         32 : The impeller according to  claim 18 , wherein a radially inner end of the second blade is located radially outside a radially outer end of the cup portion. 
     
     
         33 : The impeller according to  claim 18 , wherein when viewed in the axial direction, a length of the second blade along a direction in which the second blade extends is shorter than a length of the first blade along a direction in which the first blade extends. 
     
     
         34 : A blower comprising:
 the impeller according to  claim 18  that is rotatable about the central axis; and   a motor to drive the impeller.