Fan

Abstract

A fan includes an impeller including an impeller plate and a motor including a rotor with a rotor plate. A protrusion of the impeller plate protrudes downward in an axial direction from a lower surface on a lower side in the axial direction toward the rotor plate. A plate spring of the rotor plate extends in a direction intersecting the axial direction and is bendable in the axial direction. At least a portion of the protrusion is accommodated in a hole of the rotor plate. The protrusion contacts a leading end of the plate spring while being accommodated in the hole. The plate spring is bent in the axial direction while the protrusion is in contact with the leading end of the plate spring.

What is claimed is: 
     
         1 . A fan comprising:
 an impeller including a plurality of blades disposed in a circumferential direction around a center axis; and   a motor that rotates the impeller around the center axis; wherein   the impeller includes an impeller plate that extends in a radial direction;   the motor includes a rotor including a rotor plate, which is axially opposed to at least a portion of the impeller plate and extends in the radial direction;   the impeller plate includes a protrusion protruding axially downward from a lower surface on a lower side in the axial direction toward the rotor plate;   the rotor plate includes:
 a plurality of plate springs each of which extends in a direction intersecting the axial direction and is capable of being axially bent; and 
 a hole that is opposed to a leading end of the plate spring and accommodates at least a portion of the protrusion therein; 
   the protrusion contacts the leading end of the plate spring while being accommodated in the hole; and   the plate spring is axially bent while the protrusion is in contact with the leading end of the plate spring.   
     
     
         2 . The fan according to  claim 1 , wherein each of the plate springs includes an inclined portion inclined in a direction away from the lower surface on the lower side in the axial direction of the impeller plate with respect to a direction orthogonal to the center axis. 
     
     
         3 . The fan according to  claim 1 , wherein
 the impeller plate includes a plurality of the protrusions arranged in a circumferential direction; and   the rotor plate includes a plurality of holes corresponding to the plurality of protrusions.   
     
     
         4 . The fan according to  claim 3 , wherein
 the plurality of protrusions are arranged at equal intervals in the circumferential direction; and   the plurality of holes and the plurality of plate springs are arranged at equal intervals in the circumferential direction according to the intervals of the plurality of protrusions.   
     
     
         5 . The fan according to  claim 1 , wherein a circumferential width of the plate spring is smaller than a circumferential width of the protrusion. 
     
     
         6 . The fan according to  claim 1 , wherein the protrusion and an edge of the hole are in contact with each other in a portion in which the protrusion and the edge are opposed to each other in the circumferential direction. 
     
     
         7 . The fan according to  claim 1 , wherein a number of protrusions is an integral multiple of a number of blades. 
     
     
         8 . The fan according to  claim 1 , wherein
 the rotor further includes a cylindrical rotor tube extending axially downward from the rotor plate and having the center axis as a center;   the impeller further includes a tubular impeller tube, which extends axially downward from the impeller plate portion and has the center axis as a center;   the impeller tube includes a plurality of ribs, which are disposed on an inner circumferential surface on a radial interior and extend in the axial direction;   ends on the radial interior of the plurality of ribs come into contact with an outer circumferential surface on a radial exterior of the rotor tube while the rotor tube is fitted in the impeller tube; and   a number of the ribs is an integral multiple of a number of protrusions.   
     
     
         9 . The fan according to  claim 1 , wherein
 the motor further includes a stator disposed on a radially inside of the rotor, the stator including:   a stator core including an annular core back around the center axis and a plurality of teeth extending radially outward from the core back; and   a plurality of coils corresponding to the plurality of teeth;   each of the coils is wound around a corresponding one of the plurality of teeth; and   at least a portion of the protrusion is axially opposed to the core back.   
     
     
         10 . The fan according to  claim 1 , wherein the motor further includes:
 a rotation shaft around the center axis;   a bearing that supports the rotation shaft; and   a bearing housing that accommodates the bearing; wherein   at least a portion of the protrusion is axially opposed to the bearing housing.   
     
     
         11 . The fan according to  claim 1 , wherein the leading end of the plate spring faces the center axis. 
     
     
         12 . The fan according to  claim 11 , wherein
 an outer edge on the radial exterior of the rotor plate has a circular shape; and   the leading end of the plate spring is located closer to the center axis with respect to a midpoint of a shortest distance between the outer edge of the rotor plate and the center axis.   
     
     
         13 . The fan according to  claim 1 , wherein the leading end of the plate spring faces an exterior in the radial direction. 
     
     
         14 . The fan according to  claim 1 , wherein the leading end of the plate spring faces a rotation direction of the rotor. 
     
     
         15 . The fan according to  claim 1 , wherein a circumferential width of a base end of the plate spring is larger than a circumferential width of the leading end of the plate spring. 
     
     
         16 . The fan according to  claim 1 , wherein a circumferential width of a base end of the plate spring is equal or substantially equal to a circumferential width of the leading end of the plate spring. 
     
     
         17 . The fan according to  claim 1 , wherein
 the impeller plate is made of resin; and   the rotor plate is made of metal.   
     
     
         18 . The fan according to  claim 1 , wherein the impeller is an axial flow impeller in which air is sent toward the axial direction.