Blower

Abstract

A blower includes a casing having an intake hole which opens on one side in an axial direction. The axial direction is defined by an axis extending along a length of the casing. Within the casing, a centrifugal fan is housed. The centrifugal fan has blades arranged circumferentially about the axis. Each pair of adjacent blades defines an air flow path between them. The blades rotate in one direction about the axis, drawing air from one side through the intake hole into the air flow path, and discharge it outward in a radial direction with respect to the axis. Additionally, at least one guide may be included, having a guide surface which directs air into the air flow path. This causes the air to swirl in the rotational direction while being drawn into the air flow path of the centrifugal fan.

What is claimed is: 
     
         1 . A blower comprising:
 a casing having an intake hole opening on one side in an axial direction in which an axis extends is the axial direction;   a centrifugal fan housed within the casing, the centrifugal fan including blades arranged in a circumferential direction about the axis, each pair of adjacent blades defining an air flow path therebetween, and the blades rotating in one rotational direction about the axis for drawing air from the one side in the axial direction through the intake hole into the air flow path and discharging the drawn air outward in a radial direction with respect to the axis; and   at least one guide having a guide surface directing air into the air flow path such that the air swirls in the one rotational direction while being drawn into the air flow path of the centrifugal fan, wherein   the at least one guide is configured such that a main stream of air flowing from the one side to another side in the axial direction and drawn into the air flow path is directed toward a direction of a main stream of air flowing through the air flow path.   
     
     
         2 . The blower according to  claim 1 , wherein
 the guide surface is formed such that the guide surface is inclined in a direction opposite to the one rotational direction as the guide surface extends from an inner side to an outer side in the radial direction with respect to the axis.   
     
     
         3 . The blower according to  claim 2 , wherein
 the guide surface is a first guide surface provided on a side in the one rotational direction of the at least one guide,   the at least one guide has a second guide surface provided on another side in the opposite rotational direction, and   the second guide surface is formed such that the second guide surface is inclined in the direction opposite to the rotational direction as the second guide surface extends from the inner side to the outer side in the radial direction with respect to the axis, and guiding the air to be drawn into the air flow path of the centrifugal fan such that the air swirls in the one rotational direction.   
     
     
         4 . The blower according to  claim 3 , wherein
 the first guide surface is formed in an arcuate shape being convex in the one rotational direction, and   the second guide surface is formed in an arcuate shape being concave in the one rotational direction.   
     
     
         5 . The blower according to  claim 3 , wherein
 a distance between the first guide surface and the second guide surface is a thickness, and   the thickness of the at least one guide decreases from the outer side to the inner side in the radial direction with respect to the axis.   
     
     
         6 . The blower according to  claim 1 , wherein
 the at least one guide is one of guides arranged at intervals in the circumferential direction about the axis.   
     
     
         7 . The blower according to  claim 6 , wherein
 the guides are arranged at equal intervals in the circumferential direction.   
     
     
         8 . The blower according to  claim 1 , wherein
 the casing has an intake-hole forming portion defining the intake hole, and   the at least one guide is positioned inward of the intake-hole forming portion in the radial direction with respect to the axis.   
     
     
         9 . The blower according to  claim 1 , wherein
 the casing has an intake-hole forming portion defining the air intake hole,   the intake-hole forming portion has a forming portion end surrounding an intake-hole end positioned furthest on another side in the axial direction of the intake hole,   an inner guide region is a region of the at least one guide positioned inward of the intake-hole forming portion in the radial direction with respect to the axis, and   another end portion of the inner guide region in the axial direction is positioned on another side in the axial direction relative to the forming portion end.   
     
     
         10 . The blower according to  claim 1 , wherein
 the at least one guide is positioned outside the casing,   a guide end portion is an end portion of the at least one guide on the one side in the axial direction,   an outer half region is a region of the at least one guide positioned outside in the radial direction with respect to the axis,   an inner half region is a region of the at least one guide positioned inside relative to the outer half region in the radial direction with respect to the axis, and   the guide end portion in the outer half region is positioned further on the one side in the axial direction compared to the guide end portion in the inner half region.   
     
     
         11 . The blower according to  claim 1 , wherein
 the at least one guide is provided separately from the casing.