JP3624562B2 - Electric blower - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric blower used for a vacuum cleaner or the like.
[0002]
[Prior art]
A conventional electric blower will be described with reference to FIGS. That is, the electric blower 1 forms an outline by a load side bracket A2 formed of resin and an anti-load side bracket B3 formed of resin, and a stator 4 is fixed in the anti-load side bracket B3, The plurality of bosses 5 formed on the load side bracket A2 are in contact with the upper end surface of the stator 4 to fix the stator 4. The bearing 7 fixed to the load side of the rotor 6 was fixed by the bracket A2, and the bearing 8 fixed to the non-load side was fixed by the bracket B3.
[0003]
A shaft 9 constituting the rotor 6 protrudes from the bracket A2, and an impeller 10 that rotates together with the shaft 9 and an air guide 11 are arranged on the outer periphery thereof, and a casing 12 covers them. A blade 14 constituting a plurality of guide channels 13 facing the outer periphery of the impeller 10 is formed in the upper part of the air guide 11, and a return guide channel 15 communicating with the guide channel 13 is formed in the lower part of the air guide 11. The return guide vane 16 was formed, and the return guide vane 16 was in contact with the bracket B3.
[0004]
In the conventional electric blower 1, air is sucked by the impeller 10 rotating at a high speed together with the rotor 6, and the sucked air is discharged from the outer periphery of the impeller 10. The discharged air is guided into the guide channel 13 constituted by the blades 14 of the air guide 11 and gradually decreases the pressure, thereby reducing the pressure loss (energy loss). Further, the air discharged from the guide channel 13 is guided to the return guide channel 15 constituted by the return guide vanes 16 and the bracket B3, and the motor 6 and the stator 4 in the electric blower 1 are cooled and then electrically driven. It was discharged out of the blower 1. It is necessary to provide an insulation distance from the charging part by forming the bracket A2 for fixing the bearing 7 fixed on the load side of the rotor 6 and the bracket B3 for fixing the bearing 8 fixed on the non-load side with resin. Therefore, it can be miniaturized and can be easily combined with electrical parts.
[0005]
[Problems to be solved by the invention]
However, in the return flow path 15, air turbulence is generated at the corner corner (A portion in the figure) formed by the bracket B <b> 3, so that smooth air flow is hindered and performance is deteriorated. Also, when the casing 12 is press-fitted and held in the bracket B3, the dimensional accuracy of the outer periphery of the casing 12 press-fitting portion of the bracket B3 is important, but since the bracket B3 is made of resin, the dimensional accuracy does not come out, In addition, there is a risk of looseness in the press-fit portion due to shrinkage due to environmental changes of the resin.
[0006]
The present invention is intended to solve the conventional problems as described above, and aims to improve performance and reliability of holding of the casing.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a return guide flow communicating with the guide flow path is formed at the lower portion of the air guide, and a plurality of blades constituting a plurality of guide flow paths facing the outer periphery of the impeller are formed. A return guide vane constituting a path is formed, a curved surface portion is formed on the bracket B facing the return guide vane, and a curved surface dimension of the curved surface portion is between a minimum dimension between the blades and a height of the return guide vane. By setting, it is possible to prevent the turbulent air flow by the curved surface portion formed in the bracket B in the return flow path, so that the performance can be improved, and by forming the groove in the bracket B, the elasticity of the press-fitting portion of the bracket B can be improved. The holding of the casing can be ensured by holding.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 of the present invention includes a bracket A for holding a load side shaft of a rotor via a bearing, a bracket B formed of resin and holding an anti-load side shaft of a rotor via a bearing, and the rotor An impeller fixed to the load side shaft of the load, an air guide disposed on the outer periphery of the impeller, and a casing covering them, and a blade that constitutes a plurality of guide passages facing the outer periphery of the impeller at the upper portion of the air guide A return guide vane constituting a return guide channel communicating with the guide channel is formed at a lower portion thereof, a curved surface portion is formed on the bracket B facing the return guide vane, and a curved surface of the curved surface portion is formed. By setting the dimension between the minimum dimension between the adjacent blades and the height of the return guide blade, the turbulent air flow is caused by the curved surface formed on the bracket B in the return flow path. Can be prevented with attained performance improvements, it can be securely held in the casing by giving the elasticity of the press-fitting portion of the bracket B by forming a groove in the bracket B.
[0009]
According to a second aspect of the present invention, a curved surface portion is formed on the bracket B facing the return guide blade of the air guide, and the return guide blade is curved so as to follow the curved surface portion. The guide channel can be made longer and the pressure of the air can be reduced gradually, and the curved surface formed on the bracket B in the return channel can prevent turbulent air flow, thus further improving the performance. .
[0010]
According to a third aspect of the present invention, a curved surface portion is formed in the bracket B facing the return guide vane of the air guide, and a plurality of groove portions into which the return guide vane can be fitted are formed in the curved surface portion. Thus, by fitting the return guide vane into the groove portion formed in the curved surface portion formed in the bracket B in the return flow path of the air guide, the pressure is prevented by blocking the air flow between the adjacent return guide flow paths. Can be made uniform, and air turbulence can be prevented, so that the performance can be further improved.
[0011]
The invention according to claim 4 of the present invention is such that a rectifying plate positioned in the return guide flow path of the air guide is formed on the bracket B, and the curved surface portion formed on the bracket B in the return guide flow path is rectified. The plate can rectify the air flow and prevent turbulent flow, thus further improving performance.
[0012]
【Example】
(Example 1)
An embodiment of the present invention will be described below with reference to FIGS. In the figure, 17 is an electric blower main body, and in this main body 17, a rotor 20 in which bearings 19 are press-fitted on both sides of a shaft 18 is held by a bracket A21 made of resin and a bracket B22 made of resin. Has been.
[0013]
The bracket B22 has a substantially cylindrical shape, and holds the brush holder 23 below the bracket B22 and has an exhaust port 24 opened. On the load side of the rotor 20, the shaft 18 protrudes through the bracket A 21, and the impeller 25 is fixed thereto, and rotates together with the rotor 20 at a high speed (36000 rpm). A casing 26 covers the top of the impeller 25, and an air inlet 26a is opened at the center of the casing 26 so as to oppose the air inlet 25a of the impeller 25. An air guide 27 is disposed on the outer periphery of the impeller 25. A stator 28 is fixed in the bracket B22.
[0014]
Further, a wing 30 constituting a plurality of guide passages 29 facing the outer periphery of the impeller 25 is formed in the upper portion of the air guide 27, and a return guide passage 31 communicating with the guide passage 29 is formed in the lower portion thereof. The return guide vane 32 is formed, and the curved surface portion 33 is formed on the bracket B22 facing the return guide vane 32. The R dimension of the curved surface portion 33 is set to the minimum dimension between the adjacent blades 30 (the inlet side of the guide channel). ) To the height dimension of the return guide vane 32. A groove 22a is formed on the outer periphery of the bracket B22.
[0015]
The operation of the above configuration is as follows. That is, when the impeller 25 rotates at a high speed together with the rotor 20, air is sucked from the intake port 26 a of the casing 26 and the suction port 25 a of the impeller 25, and the sucked air is discharged from the outer periphery of the impeller 25 at a high speed. The discharged air is guided into a guide channel 29 formed of a plurality of blades 30 above the air guide 27.
[0016]
Then, the large dynamic pressure of the air at the entrance side of the guide channel 29 is gradually decreased by deceleration, and the decrease is changed to increase in static pressure, thereby reducing the pressure loss (energy loss) and improving the blowing efficiency. It is to improve. Further, the air discharged from the guide channel 29 is guided to the return guide channel 31 constituted by the return guide vanes 32 and the bracket B22, and after cooling the rotor 20 and the stator 28 in the electric blower 17, the brackets are cooled. It is discharged from the exhaust port 24 formed in B22.
[0017]
At this time, the air flow guided into the return flow path 31 can prevent air turbulence and separation by the curved surface portion 33 formed on the bracket B22 in the return flow path 31, so that the performance can be improved. is there. The curved surface size of the curved surface portion 33 in this case depends on the rotational speed of the impeller 25, the speed of the discharged air, and the shape of the return guide blade 32, but this curved surface size is the minimum dimension between the adjacent blades 30 (guide flow). A good result was obtained if it was set between the height dimension of the return guide vanes 32 from the entrance side of the road). As a result, as shown in FIG. 4, the efficiency of the motor fan exceeds 47% in the setting range from the final dimension 2.5 mm between the blades 30 to the height dimension 10 mm of the guide vanes 32. As shown in FIG. 4B, the curved surface dimension has a curved surface portion 33 having a radius R with a center point O as the center, and the curved surface portion is not a spherical surface.
[0018]
In addition, since the groove 22a is formed in the bracket B22, the elasticity of the press-fit portion is increased, so that the casing 26 can be securely held even if the outer diameter dimensional accuracy is poor and the play of the casing 26 due to resin contraction is prevented. It can be done.
[0019]
(Example 2)
A second embodiment of the present invention will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0020]
A curved surface portion 33 is formed on the bracket B22 facing the return guide blade 32 of the air guide 27, and the return guide blade 32 is curved along the curved surface portion 33. Therefore, since the outer diameter of the air guide 27 can be increased, the length of the guide channel 29 can be made longer than that in the first embodiment. Therefore, the change from the dynamic pressure of the air to the static pressure can be made more gradual, and the curved surface portion 33 formed on the bracket B22 in the return flow path 31 can prevent air turbulence and separation. The performance can be improved.
[0021]
(Example 3)
A third embodiment of the present invention will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0022]
A curved surface portion 33 is formed in the bracket B22 facing the return guide vane 32 of the air guide 27, and a plurality of groove portions 34 are formed in the curved surface portion 33. Then, the return guide wing 32 is fitted in the groove 34.
[0023]
Therefore, by blocking the air flow between the adjacent return guide flow paths 31, the air pressure in each return guide flow path 31 can be averaged, and air turbulence can be prevented, thus further improving performance. Can be planned.
[0024]
(Example 4)
A fourth embodiment of the present invention will be described with reference to FIGS. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0025]
A rectifying plate 35 located in the return guide channel 31 of the air guide 27 is formed in the bracket B22. Therefore, the air flow can be smoothed by rectifying the turbulent air flow guided into the return guide flow path 31, and the turbulent air flow and separation can be prevented by the curved surface portion 33 formed in the bracket B22. Therefore, the performance can be further improved.
[0026]
【The invention's effect】
According to the first aspect of the present invention, the air guide is formed at its upper part with blades constituting a plurality of guide channels opposed to the outer periphery of the impeller, and at its lower part, the return is communicated with the guide channel. A return guide vane constituting the guide flow path is formed, a curved surface portion is formed on the bracket B facing the return guide vane, and the curved surface dimension of the curved surface portion is increased from the minimum dimension between the adjacent blades to the height of the return guide vane. Because the curved portion formed in the bracket B in the return flow path can prevent air turbulence, the performance can be improved and the bracket B can be formed by forming a groove in the bracket B. The holding of the casing can be ensured by providing elasticity of the press-fitting portion.
[0027]
According to the invention of claim 2 of the present invention, a curved surface portion is formed in the bracket B facing the return guide blade of the air guide, and the return guide blade is curved so as to follow the curved surface portion. The air guide's guide channel can be made longer and the air pressure can be reduced gradually, and the curved surface formed on the bracket B in the return channel can prevent air turbulence, further improving performance. Can be planned.
[0028]
According to the third aspect of the present invention, the curved surface portion is formed in the bracket B facing the return guide vane of the air guide, and a plurality of groove portions into which the return guide vane can be fitted are formed in the curved surface portion. The air guide between the adjacent return guide channels is blocked by fitting the return guide vanes into the groove formed on the curved surface formed on the bracket B in the return channel of the air guide. As a result, the pressure can be made uniform and the turbulent air flow can be prevented, so that the performance can be further improved.
[0029]
According to the fourth aspect of the present invention, the rectifying plate located in the return guide channel of the air guide is formed on the bracket B, and the curved surface portion formed on the bracket B in the return guide channel. Since the air flow can be rectified and the turbulent flow can be prevented by the current plate, the performance can be further improved.
[Brief description of the drawings]
FIG. 1 is a partially cutaway side view of an electric blower showing a first embodiment of the present invention. FIG. 2 is a partial sectional side view of the electric blower. FIG. 3 is a partial plan view of an air guide of the electric blower. 4) (a) Relationship diagram between efficiency and curved surface dimensions of the electric blower (b) Explanatory diagram of curved surface dimensions of the electric blower FIG. 5 is a partial sectional side view of the electric blower showing a second embodiment of the present invention. FIG. 6 is a partial sectional side view of an electric blower showing a third embodiment of the present invention. FIG. 7 is a partial sectional side view of an electric blower showing a fourth embodiment of the present invention. FIG. 9 is a partially cutaway side view of a conventional electric blower. FIG. 10 is a partial sectional side view of the electric blower.
17 Electric blower body 20 Rotor 21 Bracket A
22 Bracket B
22a groove 25 impeller 27 air guide 29 guide channel 30 blade 31 return guide channel 32 return guide blade 33 curved surface portion 34 groove portion 35 current plate

Claims (4)

A bracket A for holding the load side shaft of the rotor via a bearing, a bracket B formed of resin for holding the anti-load side shaft of the rotor via a bearing, an impeller fixed to the load side shaft of the rotor, An air guide disposed on the outer periphery of the air guide and a casing covering the air guide are provided. A blade that forms a plurality of guide passages facing the outer periphery of the impeller is formed in the upper portion of the air guide, and the guide is formed in the lower portion thereof. Forming a return guide vane constituting a return guide channel communicating with the flow channel, forming a curved surface portion on the bracket B facing the return guide vane, and determining a curved surface dimension of the curved surface portion as a minimum dimension between the adjacent blades The electric blower which is set between the height dimensions of the return guide vanes and further has a groove formed in the outer peripheral portion of the casing holding portion of the bracket B. The electric blower according to claim 1, wherein a curved surface portion is formed on the bracket B facing the return guide blade of the air guide, and the return guide blade is curved so as to follow the curved surface portion. The electric blower according to claim 1 or 2, wherein a curved surface portion is formed in the bracket B facing the return guide blade of the air guide, and a plurality of groove portions into which the return guide blade can be fitted are formed in the curved surface portion. The electric blower according to any one of claims 1 to 3, wherein a rectifying plate located in the return guide flow path of the air guide is formed on the bracket B.

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