JP2011185166A - Blower fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blower fan with an impeller suppressing deterioration of impeller characteristics due to interference of an air flow generated by rotation of rotor blades with a connection part. <P>SOLUTION: The blower fan 2 includes a cylindrical cup part 10. the plurality of rotor blades 11, a motor rotating the plurality of rotor blades 11, and a housing 30. The plurality of rotor blades 11 are connected with each other by the annular connection part 12. The connection part 12 is formed at a position in 70% to 90% of the blade length from the roots of the rotor blades 11 at the outer peripheral face of the cup part 10 with respect to the blade length of the rotor blades 11 along the radial direction. Further, the housing 30 and a base part 24 are connected through a plurality of stator blades 31. The plurality of stator blades 31 are connected by a second annular connection part 32 and the second connection part 32 are arranged radially inward of the first connection part 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a blower fan provided with an impeller that generates an air flow along a central axis.

  An impeller used for a conventional so-called axial fan (blower fan) is arranged along the direction of the central axis by rotating a plurality of moving blades fixed to the outer peripheral surface of a cylindrical impeller cup around the central axis. Generate air flow.

  Here, when the impeller rotates, a radial centrifugal force acts on the rotor blade. The effect of this centrifugal force becomes more pronounced as the impeller rotates at a higher speed. In addition, in the case of a moving blade with a high degree of advancement, since the radially outer end of the moving blade is positioned forward in the rotational direction from the root of the moving blade, the root of the moving blade is caused by the centrifugal force generated in each part of the moving blade. A large moment is generated. Therefore, the impeller is required to have a strength design that considers the influence of such centrifugal force.

  In order to reduce the influence of the centrifugal force, a technique for increasing the strength of the moving blade against the centrifugal force by connecting a plurality of moving blades to each other through an annular connecting portion is disclosed in US Patent Application Publication No. 2008/0056899. U.S. Pat. No. 6,554,574 and U.S. Pat. No. 6,241,474.

On the other hand, a swirl flow is always generated behind the rotor blades of the axial fan. For the purpose of turning this swirl flow into an axial flow, the swirl flow is radially formed on the outer peripheral surface of the motor support (base) that rotates the impeller. A technique for providing a plurality of stationary vanes is known. However, since the plurality of stationary blades are fixed to the outer peripheral surface of the base portion, the strength of the base portion is reduced. Therefore, Japanese Patent Application Laid-Open No. 2008-261280 discloses a technique for improving the strength of the base portion by connecting a plurality of stationary blades to each other with an annular connecting portion. Japanese Patent Laying-Open No. 2005-76590 discloses a technique for changing the characteristics of the air flow by making the connecting portion into a specific shape.
US Patent Application Publication No. 2008/0056899 US Pat. No. 6,554,574 US Pat. No. 6,241,474 JP 2008-261280 A JP 2005-76590 A

  However, the above Patent Documents 1 to 3 do not consider the influence of the impeller characteristics due to the interference between the air flow generated by the rotation of the moving blade and the connecting portion connecting the moving blade.

  Further, in Patent Documents 4 to 5, the influence of the impeller characteristic due to the positional relationship between the connecting portion that connects the moving blades and the connecting portion that connects the stationary blades is not considered.

  An object of the present invention is to provide a blower fan including an impeller that suppresses deterioration of impeller characteristics due to interference between an air flow generated by rotation of a moving blade and a connecting portion.

  In order to solve the above-described problem, the present invention provides an impeller having an annular connecting portion that connects a plurality of moving blades to each other, and the connecting portion is connected to the blade length along the radial direction of the moving blade. Adopting a configuration in which an annular connecting part that connects a plurality of stationary blades is arranged radially inward from the connecting part of a plurality of moving blades at a position 70% to 90% of the blade length from the root of the blade To do.

  That is, the blower fan according to one aspect of the present invention is fixed to the substantially cylindrical cup portion that rotates about the central axis and the outer peripheral surface of the cup portion, and rotates together with the cup portion, thereby sucking air from one side in the axial direction. A plurality of moving blades that exhaust in the other axial direction, a motor that rotates the plurality of moving blades together with the cup portion, a base portion that supports the motor, and a housing that surrounds the outer periphery of the plurality of moving blades. Are connected to each other by a substantially ring-shaped first connecting portion, and the first connecting portion is connected to the blade length along the radial direction of the moving blade, at the root of the outer peripheral face of the cup portion of the moving blade. Are formed in a substantially cylindrical shape at a position of 70% to 90% of the blade length, the housing and the base portion are connected by a plurality of stationary blades, and the plurality of stationary blades are substantially annular first. Are connected to each other by two connecting portions, Parts is characterized by being arranged from the first connecting portion radially inward.

  Here, the second connecting portion is disposed radially inward within a range of 50 to 65% of the distance from the first connecting portion to the distance between the outer periphery of the cup portion and the first connecting portion. It is preferable.

  According to the present invention, in an impeller including an annular first connecting portion that connects a plurality of moving blades, the first connecting portion is connected to the blade length along the radial direction of the moving blade. By forming at a position of 70% to 90% of the blade length from the root, an increase in noise due to interference between the air flow and the connecting portion can be suppressed, and an annular second connecting portion that connects a plurality of stationary blades is provided. By disposing radially inward from the first connecting portion, it is possible to suppress a decrease in static pressure at maximum efficiency. Thereby, since a high intensity | strength ventilation fan is realizable, suppressing the fall of an impeller characteristic, design of a ventilation fan with a high freedom degree is attained.

It is the top view seen from the axial direction intake side of the impeller in one Embodiment of this invention. It is a side view of the impeller of FIG. It is sectional drawing which showed the structure of the ventilation fan provided with the impeller of FIG. It is the graph which showed the static pressure characteristic and noise characteristic of each impeller about the some sample of the impeller in which the 1st connection part was formed in a different position. It is sectional drawing which showed the structure of the ventilation fan in one Embodiment of this invention. It is the table | surface which each showed the boss | hub part radius in the ventilation fan produced using two types of stationary blades X and Y, the distance of the 1st connection part, and the distance of the 2nd connection part. It is the graph which showed the static pressure characteristic of the ventilation fan produced using the stationary blades X and Y of FIG. It is the top view which looked at the housing of the ventilation fan in one Embodiment of this invention from the axial direction intake side.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description of the present embodiment, a direction parallel to the central axis is referred to as “axial direction”, and a radial direction centered on the central axis is referred to as “radial direction”. In addition, this invention is not limited to the following embodiment. Moreover, it can change suitably in the range which does not deviate from the range which has the effect of this invention.

  FIG. 1 is a plan view of an impeller 1 according to an embodiment of the present invention as viewed from the axial intake side, and FIG. 2 is a side view of the impeller 1 of FIG. FIG. 3 is a cross-sectional view of the blower fan 2 including the impeller 1 of FIG.

  As shown in FIGS. 1 and 2, the impeller 1 in the present embodiment is fixed to a substantially cylindrical cup portion 10 that rotates about a central axis J and an outer peripheral surface 10 a of the cup portion 10. By rotating, a plurality of moving blades 11 that intake air from one side in the axial direction and exhaust air to the other side in the axial direction, and a substantially annular connecting portion 12 that connects the plurality of moving blades 11 to each other are provided. Here, the connection part 12 is formed in the substantially cylindrical shape in the circumferential direction along the arbitrary circle centering on the central axis J. As shown in FIG.

  In addition, as shown in FIG. 3, the blower fan 2 in the present embodiment includes a motor that drives the impeller 1, a base portion 24 that supports the motor, a housing 30 that surrounds the outer periphery of the impeller 1, and a housing 30 and a base portion. 24 and a plurality of stationary blades 31 that are connected to each other.

  The motor includes a rotor holder 22 and a rotor magnet 23 attached to the inner peripheral surface of the cup portion 10 of the impeller 1, a stator 26 in which a coil is wound around a stator core, and a sleeve bearing fixed inside the bearing holding portion 25. 21. The shaft 20 fixed to the center portion of the cup portion 10 is inserted into a sleeve bearing 21 and is rotatably supported.

  The blower fan 2 configured in this manner generates a rotational torque between the stator 26 and the rotor magnet 23 by supplying a drive current to the coil of the stator 26, and thereby the outer peripheral surface 10 a of the cup portion 10. A plurality of blades 11 fixed to the center of the rotor 11 rotate about the central axis J.

  The inventors of the present application have studied the influence of the impeller characteristics due to the interference between the air flow generated by the rotation of the moving blade 11 and the connecting portion 12, and as a result, important knowledge regarding the formation position of the connecting portion 12 in the radial direction of the moving blade 11. Got.

  FIG. 4 is a graph showing the static pressure characteristics and noise characteristics of the impeller 1 for a plurality of samples A to E of the impeller 1 in which the connecting portions 12 are formed at different positions with respect to the radial direction of the moving blade 11. . Here, in the samples A to E, as shown in FIG. 1, the connecting portion 12 is connected to the blade length La along the radial direction of the moving blade 11 from the root of the cup outer peripheral surface 10 a of the moving blade 11. The distance Lb to the portion 12 is formed at a position where the distance Lb is 50%, 70%, 80%, 90%, and 100% of the blade length La. Curves G1b to G5b in the figure show the results of measuring the relationship between the air volume and static pressure of samples A to E, and curves G1a to G5a show the results of measuring the relationship between the air volume and noise of samples A to E, respectively. It is a thing.

  As shown in FIG. 4, in the samples A and E (curves G1a and G5a) where the position of the connecting portion 12 corresponds to 50% and 100%, the positions of the connecting portion 12 correspond to 70%, 80% and 90%. It can be seen that the noise increases compared to samples B, C, and D (curves G2a, G3a, and G4a). The reason for the increase in noise in the sample A is considered to be that the interference between the air flow and the connecting portion 12 becomes large in the radial center portion of the rotor blade 11 because the contribution of air flow generation is large. Moreover, the noise increases in the sample E because the air flow in the reverse direction is generated in the gap between the connecting portion 12 and the side wall of the housing when the connecting portion 12 is provided at the radially outer end 11b of the moving blade 11. it is conceivable that.

  Therefore, the connecting portion 12 is formed at a position 70% to 90% of the blade length La from the root of the moving blade 11 with respect to the blade length La along the radial direction of the moving blade 11. The increase in noise due to the application of can be suppressed.

  In addition, since the connecting portion 12 is disposed radially inward from the radially outer end 11b of the rotor blade 11, in the region 11A of the rotor blade 11 positioned radially inward from the connecting portion 12, The inner surface of the connecting portion 12 serves as the inner surface of the housing. That is, there is no gap between the inner surface of the virtual housing (the inner surface of the connecting portion 12) and the region 11 </ b> A of the moving blade 11 located radially inward of the connecting portion 12. Therefore, in the region 11A of the rotor blade 11 that is located radially inward of the connecting portion 12, it is difficult for the backflow of airflow to occur, and most of the backflowing airflow is radially outward from the connecting portion 12. It passes through the region 11B of the moving blade 11 located. As a result, the region 11B of the moving blade 11 positioned radially outward from the connecting portion 12 can function exclusively for preventing the backflow of airflow. Thereby, it is possible to improve the static pressure characteristics on the low air volume side while securing the air volume characteristics of the impeller 1 in the region 11A of the rotor blade 11 located radially inward of the connecting portion 12.

  In addition, although the intensity | strength of the moving blade 11 with respect to a centrifugal force is raised by mutually connecting the several moving blade 11 with the connection part 12, when the moving blade 11 is comprised as an advance blade, the effect is exhibited especially. The Here, as shown in FIG. 1, the forward blade is a front edge 11 a positioned at the forefront in the rotational direction R of the moving blade 11 and a moving blade end 11 b positioned at the radially outer end of the moving blade 11. The intersection point P1 is located on the front side in the rotational direction R with respect to the intersection point P2 between the front edge 11a and the outer peripheral surface 10a of the cup portion 10. Further, when the degree of forward movement is extremely large, that is, as shown in FIG. 1, the trailing edge 11 c located at the rear of the moving blade 11 in the rotation direction R and the moving blade tip located at the radially outer end of the moving blade 11. When the intersection P3 with 11b is located in the front side of the rotation direction R rather than the intersection P2 of the front edge 11a located in front of the rotation direction R of the moving blade 11 and the outer peripheral surface 10a of the cup part 10. Further, the effect can be exhibited.

  Incidentally, as shown in FIG. 5, the inventors of the present application have examined the static pressure characteristics of the blower fan in which a plurality of stationary blades 31 are connected to each other by a substantially annular connecting portion 32. It has been found that the static pressure at the maximum efficiency may not be sufficiently increased depending on the arrangement position of the connecting portion (second connecting portion) 32 provided on the stationary blade 31 with respect to the connecting portion (first connecting portion) 12. .

  FIG. 6 is a table showing the boss portion radius, the distance of the first connecting portion, and the distance of the second connecting portion in the blower fan manufactured using two types of stationary blades X and Y. FIG. It is the graph which showed the static pressure characteristic of the ventilation fan produced using the stationary blades X and Y.

  Here, as shown in FIG. 5, the produced blower fan has a radius (A) of the cup portion 10 of 31.5 mm and a distance (B) from the side surface of the cup portion 10 of the first connecting portion 12 of 18.7. It was 25 mm. Further, the distance (C) of the second connecting portion 32 from the first connecting portion 12 was set to 10.45 mm for the stationary blade X and −2.25 mm for the stationary blade Y. In the stationary blade X, the second coupling portion 32 is disposed radially inward from the first coupling portion 12, and in the stationary blade Y, the second coupling portion 32 is diameterd from the first coupling portion 12. It is arranged outside the direction.

  In the graph of FIG. 7, the curve L1 indicates the static pressure characteristic of the blower fan manufactured using the stationary blade X, and the curve L2 indicates the static pressure characteristic of the blower fan manufactured using the stationary blade Y. As shown in FIG. 7, in the blower fan in which the second connecting portion 32 is arranged radially outward from the first connecting portion 12, the static pressure at the highest efficiency is reduced, whereas the second connecting portion 32 It can be seen that in the blower fan in which the portion 32 is disposed radially inward from the first connecting portion 12, the reduction in static pressure at the maximum efficiency is suppressed.

  Thus, the static pressure at the highest efficiency is reduced in the blower fan in which the second connecting portion 32 is arranged radially outward from the first connecting portion 12, and the cup portion 10 and the second connecting portion are reduced. It is considered that a large stable air vortex is generated between the second connecting portion 32 and the flow path between the second connecting portion 32 and the first connecting portion 12 is narrowed. On the other hand, in the blower fan in which the second connecting portion 32 is arranged in the radial direction from the first connecting portion 12, the cup portion 10 and the second connecting portion are suppressed from decreasing in static pressure at the maximum efficiency. It is considered that the flow path between the second connecting portion 32 and the first connecting portion 12 is widened because an increase in the air vortex generated between the second connecting portion 32 and the first connecting portion 12 is suppressed.

  As shown in FIG. 6, in the stationary blade X, the ratio (C / B) of the distance (C) of the second connecting portion 32 to the distance (B) of the first connecting portion 12 is 0.57. The position where the second connecting portion 32 is disposed is near the center with respect to the region 11A of the moving blade 11 located radially inward of the first connecting portion 12. By arranging the second connecting portion 32 in the vicinity of the center of the region 11A of the moving blade 11, the air vortex is prevented from becoming large between the cup portion 10 and the second connecting portion 32, so that the highest efficiency is achieved. The decrease in static pressure can be further suppressed. From this, the second connecting portion 32 is located near the center of the region 11A of the rotor blade 11, that is, from the first connecting portion 12, the distance (B) between the outer periphery of the cup portion 10 and the first connecting portion 12. On the other hand, it is preferable to arrange radially inward within a range of 50 to 65% of the distance (B).

  FIG. 8 is a plan view of the blower fan 2 in the present embodiment as viewed from the axial suction side. As shown in FIG. 8, the base portion 24 and the housing 30 are coupled by a plurality of stationary blades 31, and the plurality of stationary blades 31 are coupled to each other by a substantially annular second coupling portion 32. And the 2nd connection part 32 is arrange | positioned radially inward from the 1st connection part (not shown).

  Here, the base portion 24, the housing 30, the plurality of stationary blades 31, and the second connecting portion 12 may be integrally formed by injection molding. In addition, the shape of the second connecting portion 12 is not particularly limited, but a wind collecting effect is imparted to the second connecting portion 12 by forming a band shape inclined toward the central axis toward the axial exhaust side. can do.

Claims (5)

A substantially cylindrical cup portion that rotates about a central axis;
A plurality of moving blades that are fixed to the outer peripheral surface of the cup portion and rotate together with the cup portion to suck air from one side in the axial direction and exhaust air to the other side in the axial direction;
A motor for rotating the plurality of moving blades together with the cup portion;
A base for supporting the motor;
A housing enclosing an outer periphery of the plurality of blades;
With
The plurality of moving blades are connected to each other by a substantially annular first connecting portion, and the first connecting portion is connected to the blade length along the radial direction of the moving blade with respect to the blade length. From the root of the cup outer peripheral surface, is formed in a substantially cylindrical shape at a position of 70% to 90% of the blade length,
The housing and the base portion are connected by a plurality of stationary blades, and the plurality of stationary blades are connected to each other by a substantially annular second connecting portion,
The said 2nd connection part is a ventilation fan arrange | positioned radially inward from the said 1st connection part. The blower fan according to claim 1,
The plurality of rotor blades are blower fans configured as forward blades. The blower fan according to claim 1,
The second connecting portion is arranged radially inward within a range of 50 to 65% of the distance from the first connecting portion to the distance between the outer periphery of the cup portion and the first connecting portion. Being a blower fan. The blower fan according to claim 1,
The second connecting part is a blower fan formed in a substantially cylindrical shape. The blower fan according to claim 1,
The intersection of the trailing edge located at the rear in the rotational direction of the moving blade and the moving blade end located at the radially outer end of the moving blade is a front edge located at the front in the rotational direction of the moving blade, and the cup portion. A blower fan located on the front side in the rotational direction of the intersection with the outer peripheral surface.

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