Centrifugal blower

Abstract

A centrifugal blower includes a centrifugal fan and a partition cylinder portion. The centrifugal fan includes first blades and second blades arranged about a fan central axis, a separation panel between the first blades and the second blades, and an inward extending part extending inward in a radial direction from the separation panel. The partition cylinder portion has a cylindrical shape extending in an axial direction. The partition cylinder portion is located inside the second blades in the radial direction. The partition cylinder portion partitions air drawn into spaces between the first blades from air drawn into spaces between the second blades. The separation panel has a plate shape extending in the radial direction. The inward extending part is located inside, in the radial direction, both connected ends of the first blades and connected ends of the second blades which are joined to the separation panel.

What is claimed is: 
     
         1 . A centrifugal blower comprising:
 a centrifugal fan including
 a plurality of first blades arranged about a fan central axis, 
 a plurality of second blades arranged about the fan central axis, the plurality of second blades being located on a first side of the plurality of first blades in an axial direction of the fan central axis and being aligned to the plurality of first blades, 
 a separation panel located between the plurality of first blades and the plurality of second blades, and 
 an inward extending part extending inward in a radial direction of the centrifugal fan from the separation panel; and 
   a partition cylinder portion having a cylindrical shape extending in the axial direction, a diameter of the partition cylinder portion expanding in the axial direction toward a second side that is an opposite side of the first side, the partition cylinder portion being located inside the plurality of second blades in the radial direction, wherein   the centrifugal fan is configured to rotate about the fan central axis to
 take in air from the first side into spaces between the plurality of first blades and spaces between the plurality of second blades, 
 blow out the air in the spaces between the plurality of first blades outward in the radial direction, and 
 blow out the air in the spaces between the plurality of second blades outward in the radial direction, 
   the partition cylinder portion partitions, on an airflow upstream side of the plurality of first blades and the plurality of second blades, the air taken into the spaces between the plurality of first blades through an inside of the partition cylinder portion in the radial direction from the air taken into the spaces between the plurality of second blades through an outside of the partition cylinder portion in the radial direction,   the separation panel has a plate shape extending in the radial direction and partitions the air flowing through the spaces between the plurality of first blades from the air flowing through the spaces between the plurality of second blades, and   the inward extending part is located inside, in the radial direction, both connected ends of the plurality of first blades each of which is joined to the separation panel and connected ends of the plurality of second blades each of which is joined to the separation panel.   
     
     
         2 . The centrifugal blower according to  claim 1 , wherein
 the partition cylinder portion includes the inward extending part and rotates together with the centrifugal fan.   
     
     
         3 . The centrifugal blower according to  claim 1 , wherein
 the partition cylinder portion is separated from the centrifugal fan and is a non-rotating member that is not configured to rotate, and   the partition cylinder portion partitions, on an airflow upstream side of the inward extending part, the air taken into the spaces between the plurality of first blades from the air taken into the spaces between the plurality of second blades.   
     
     
         4 . The centrifugal blower according to  claim 1 , further comprising:
 a fan casing that accommodates the centrifugal fan, the fan casing defining a fan surrounding space that surrounds the centrifugal fan outside the centrifugal fan in the radial direction, the air flowing into the fan surrounding space from the centrifugal fan; and   a partition panel that partitions the fan surrounding space in the axial direction into a first flow-out passage and a second flow-out passage, wherein   a first air flowing out of the spaces between the plurality of first blades flows into the first flow-out passage,   a second air flowing out of the spaces between the plurality of second blades flows into the second flow-out passage, and   the partition panel is configured to limit the first air from entering the second flow-out passage and limit the second air from entering the first flow-out passage.   
     
     
         5 . The centrifugal blower according to  claim 1 , further comprising:
 a filter located on a first side of the partition cylinder portion in the axial direction to filtrate the air flowing toward the centrifugal fan, wherein   the partition cylinder portion extends to the filter.   
     
     
         6 . The centrifugal blower according to  claim 1 , further comprising:
 an upstream partition wall located on a first side of the partition cylinder portion in the axial direction and separated from the partition cylinder portion, the upstream partition wall having a cylindrical shape aligned to the partition cylinder portion in the axial direction, the upstream partition wall partitioning the air flowing into the inside of the partition cylinder portion from the air flowing into the outside of the partition cylinder portion on an airflow upstream side of the partition cylinder portion; and   a filter located on a first side of the upstream partition wall in the axial direction to filtrate the air flowing toward the centrifugal fan, wherein   the upstream partition wall extends to the filter.