JP4356245B2 - Electric blower and vacuum cleaner equipped with the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor part structure for constituting a flow path for realizing a highly efficient and low noise electric blower, and a cleaner body structure using the electric blower.
[0002]
[Prior art]
As a general conventional structure of an electric blower for a vacuum cleaner, there is a structure shown in FIG. 1 of JP-A-11-190298. In the electric blower of the publication, the air flow sucked from the air intake port is boosted by a centrifugal impeller, and the remaining speed energy is converted into pressure by a static pressure recovery device including a diffuser and a return. Thereafter, the air flow leaving the return passes through the cooling passage while taking away the heat generated by the motor, and is discharged to the outside through the exhaust hole. Thereafter, the air exiting the electric blower enters the vacuum cleaner body.
[0003]
Conventionally, the outer diameter of the impeller necessary to generate a predetermined pressure is larger than the outer diameter of the motor, and the entire blower including the diffuser and the return is projected to protrude larger in the radial direction than the motor housing. . Therefore, a sudden turning flow occurred in the flow path portion from the diffuser to the return. Although the motor housing can be relaxed if the motor housing is enlarged, it has a structure in which the motor housing is sandwiched and fixed in a diagonal direction with a stator core having a rectangular parallelepiped outer shape. As another reason, the outer diameter of the motor housing may be defined by the length of the attached carbon brush. The length of the carbon brush is determined by the product life of the vacuum cleaner, and it is gradually scraped and shortened. The longer it is, the longer the life is. However, if it is too long, vibration will occur due to sliding, erosion due to electrical discharge will occur, and the life of the brush will be shortened. Presents.
[0004]
Another known example is a structure as disclosed in JP-A-11-294391. This has a large curvature so that the constricted portion of the motor housing swells outward. In this way, sudden turning from the return to the cooling flow path is mitigated.
[0005]
[Problems to be solved by the invention]
Conventionally, in the structure of Japanese Patent Application Laid-Open No. 11-190298, since the turning curvature of the static flow path is too small, the flow is separated or a strong secondary flow is generated and the fluid loss tends to increase. Further, since the motor housing is squeezed in the radial direction, the gap between the stator core and the motor housing, that is, the flow path cross-sectional area is small. Therefore, the flow after the return also has a tendency that the average flow velocity increases and the friction loss increases. For this reason, not only the efficiency of the electric blower is lowered, but also the turbulence generated by the separation and the secondary flow increases the turbulent noise.
[0006]
In the case of the structure as shown in Japanese Patent Application Laid-Open No. 11-294391, the turning of the flow at the part that enters the cooling flow path after returning is gentle, but the curved flow path from the diffuser to the return still turns suddenly. The point that is forced is not changed. In practice, it is necessary to prevent the constricted portion from being applied to the stator core for the purpose of fixing. Furthermore, it is difficult to increase the cross-sectional area of the cooling flow path.
[0007]
In view of the above problems, the present invention proposes a flow path structure from a blower part to a motor part in order to provide a high-efficiency and low-noise electric blower without changing the maximum outer diameter of the entire electric blower. To do.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the outer diameter of the motor housing is gradually enlarged from the upper part of the carbon brush toward the centrifugal impeller, and the motor housing has at least two indentations in the circumferential direction. The shape is pushed in from the outside to the inside so that it can be made, and the stator core is directly fixed by the pushed-in portion.
[0010]
Alternatively, the motor housing shape as described above is replaced with the wall surface of the electric blower chamber of the vacuum cleaner.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, about an Example of the present invention, an electric blower and a vacuum cleaner carrying it are explained using figures. First, the longitudinal cross-sectional view of the main body of the vacuum cleaner which mounts the electric blower of this invention in FIG. 3 is shown. The vacuum cleaner main body 201 is configured by a lower case 301, an upper case 302, and a dust collecting lid 303. A suction port 304 is formed in the dust collection lid 303, and a dust collection chamber 306 that houses a dust collection bag 305 joined to the suction port 304 is formed inside the dust collection lid 303. An electric blower chamber 307 is connected to the rear of the dust collection chamber 306 via a filter 309, and the electric blower 308 is accommodated. The air sucked from the suction port 304 is dust-removed by the dust bag 305, passes through the filter 309, and then flows into the electric blower 308. Exhaust gas from the electric blower 308 is discharged to the outside through the exhaust port 310. By installing the electric blower 308 of the present invention, the power at the time of dust collection of the vacuum cleaner can be increased, the noise can be reduced, and the size of the vacuum cleaner can be reduced by eliminating the need for a conventional sound insulation material. There is an effect that can be achieved.
[0012]
Next, the structure of the conventional electric blower 308 will be described with reference to FIG. The electric blower 308 for the electric vacuum cleaner is composed of the electric motor 2 and the blower 1. The electric motor 2 includes an electric motor case composed of a housing 3 and an end bracket 9, a rotor 5 having a rotating shaft 4 housed in the electric motor case, and a stator 7 around which a stator coil 6 is wound. The blower 1 includes a centrifugal impeller 12 directly connected to the rotating shaft 4, a diffuser 11 installed on the outer peripheral side of the centrifugal impeller 12, a return guide 14 positioned on the back surface of the diffuser 11, and a centrifugal impeller 12. The blower case 13 encloses the diffuser 11 and the return guide 14, has an air suction port 13b, and is connected to the motor case.
[0013]
In the electric blower 308, when the electric motor 2 is driven to rotate the centrifugal impeller 12, the air 101 flows from the air suction port 13 b and flows into the diffuser 11 adjacent to the outer peripheral portion of the centrifugal impeller 12. The air 102 flowing into the diffuser 11 is guided to the return guide 14 and flows into the housing 3. The air 104 flowing into the housing 3 is discharged to the outside after cooling the rotor 5, the stator coil 6, and the brush 15 of the electric motor 2.
[0014]
FIG. 1 shows the most typical configuration proposed by the present invention. FIG. 4 shows a perspective view of FIG. 1 three-dimensionally exploded. In the electric blower 308, the basic structure of the present invention in which the stator core 50 is sandwiched between the separate suspension members 51 and 52 and fixed to the motor housing 53 is shown. The motor housing 53 gradually increases in diameter from the upper part of the carbon brush fixing holder 65 installed in the carbon brush insertion port 54 toward the centrifugal impeller 55, and is coupled to the fan casing 56 at the fitting portion 57. The angle between the gradually expanding taper portion 66 and the rotation axis is between 25 degrees and 40 degrees. At this time, the motor housing 53 and the stator core 50 are not in contact with each other and are fixed by the upper and lower suspension members 51 and 52.
[0015]
The lower suspension member 52 has a structure having a gap in the circumferential direction as seen in FIG. 4, for example. The stator core 50 is supported by the claw 57, and the gap 58 forms a wide flow path between the motor housing. Conventionally, the stator core is in contact with the motor housing, so this gap is not present or very small. On the other hand, as shown in FIG. 4, for example, the upper suspension member 51 is fitted into the stator core and fixed to the end bracket 60 by a separately provided detent 59. The end bracket 60 is fixed to the motor housing 53 with screws or the like, and has a structure that not only prevents the upper suspension member 51 from rotating but also determines the position in the axial direction. In this way, the stator core 50 is fixed in the axial position and also in the rotational direction. Further, the end bracket 60 has a height higher than that of a known structure, and can be seen in FIG. 2 by connecting the motor housing 53 with a screw or the like in a plane parallel to the rotation shaft. Such a flange portion 107 in the plane perpendicular to the axis becomes unnecessary, and the cooling channel area can be further increased.
[0016]
According to this structure, the flow becomes 64, and it can be seen that the flow path curvature from the diffuser 61 through the return 62 to the exhaust hole 63 can be relieved significantly. In addition, the channel cross-sectional area can be increased. As a result, it is possible to reduce peeling loss and secondary flow loss due to bending, and also reduce friction loss by lowering the average flow velocity. Therefore, a highly efficient electric blower can be provided. Moreover, since the average flow velocity is reduced and the separation and the secondary flow are suppressed, the turbulence of the flow can be reduced, so that the turbulent noise can be reduced. Furthermore, the flow that normally exits the diffuser 61 has a swirl velocity component remaining, and it is the role of the return 62 to restore it to the pressure. However, in the configuration of the present invention, the end bracket 60 becomes higher. Accordingly, the return 62 is also increased, the effective blade area facing the flow is increased, and the pressure recovery amount can be further improved.
[0017]
On the other hand, in the motor, heat generation due to friction of the carbon brush is dominant. This heat generation may be cooled by the convection effect directly by the cooling air, but there are many components that conduct heat to the end bracket 60 and the motor housing 53 via the rotating shaft. In the structure of the present invention, since both the motor housing 53 and the end bracket 60 have a larger surface area than the conventional structure, the heat radiation area is increased and the cooling performance can be improved. Therefore, the vacuum cleaner can be operated for a long time with a small air volume, or the electric blower, that is, the vacuum cleaner can be further downsized by increasing the number of rotations of the electric motor.
[0018]
In FIG. 4, the end bracket 60 and the motor housing 53 are supported in a plane parallel to the rotation axis, but may be configured to be received on a plane perpendicular to the rotation axis as in the prior art. In this case, the curvature of the flow around the return 62 remains small, but the gap between the stator core 50 and the motor housing 53 through which the cooling air passes is large, so that the friction loss here can be reduced. Further, as an intermediate fixing method, a structure that is received on an oblique surface such as a tapered shape may be used.
[0019]
Further, the suspension members 51 and 52 in FIG. 4 are separate parts in this figure, but may be integrally injection molded so as to incorporate the stator core 50. In this case, since the structural members are integrated, the assembly property of the product is improved. Further, it may be integrated by post-processing such as adhesion and bonding, instead of integral molding.
[0020]
FIG. 5 is another embodiment of the present invention and shows another motor housing shape. It is the figure seen from the rotating shaft direction, and the relevance of only the stator core 70 and the motor housing 71 is shown. FIG. 6 shows an exploded perspective view thereof. Instead of using a suspension member for fixing the stator core 70 to the motor housing 71, the motor housing 71 is molded non-uniformly in the circumferential direction to form the concave portions 72 and the convex portions 73. The stator core 70 is joined to the motor housing 71 by the concave portion 72 narrowed in the radial direction. The joining means may be caulking, bolt fastening, adhesion, welding or the like. According to this method, although the rigidity of the motor housing is somewhat reduced, the suspension member is not required, so that the number of parts can be reduced and an inexpensive electric blower can be provided. As in the case of FIGS. 3 and 4, the curvature of the bending flow and the cross-sectional area of the flow path can be made larger than in the known example, and loss and turbulence noise can be reduced. Furthermore, this structure can shift the vibration eigenvalue of the motor housing to a high frequency range. As for the noise heard through the main body of the vacuum cleaner, the high frequency component of the electric blower sound is attenuated and a relatively low frequency is conspicuous, so that the low frequency sound can be reduced in the electric blower.
[0021]
The vacuum cleaner equipped with the electric blower also has the effect of the present invention. Since the electric blower of the present invention described so far can reduce noise by itself, a sound absorbing material that has been wound around the electric blower when mounted on the main body of the conventional vacuum cleaner is not necessary. Therefore, since the sound absorbing material and its space are unnecessary, a cheaper and smaller vacuum cleaner can be provided.
[0022]
FIG. 7 shows still another embodiment of the present invention. This is a case where the reduction of the flow path curvature and the expansion of the cross-sectional area of the flow path, which are the physical principles of the invention effect, are achieved when the cleaner body 202 is mounted. The vacuum cleaner is usually provided with a box-shaped electric blower chamber in which the electric blower is housed. In this embodiment, the wall surface of the electric blower chamber 310 is used as a motor housing. In this case, since the motor housing is removed, the stator core 311 which is a motor side part of the electric blower, the commutator 312 in contact with the carbon brush, the rotating shaft 313 and the like are exposed to the outside, and the post 314 which maintains strength is used. The rotary bearing will be supported. On the other hand, since the wall surface 315 of the electric blower chamber 310 forms a motor cooling flow path instead of the motor housing, the flow from the return is discharged from the electric blower chamber through the exhaust port 317 like the cooling air 316. The
[0023]
This configuration makes it possible to remove the heaviest motor housing among the parts of the electric blower, and can greatly reduce the weight of the vacuum cleaner in addition to high efficiency and low noise. Moreover, since the shape of the wall surface 315 of the electric blower chamber has a higher degree of freedom than the motor housing, it is possible to take a wider flow path. In addition, since a larger space is secured after the diffuser return than the method using the conventional motor housing and can be used as a large-capacity acoustic filter, it is possible to reduce low-frequency noise that is difficult to eliminate.
[0024]
【The invention's effect】
According to the present invention, the curvature of the cooling flow path from the diffuser to the return and exhaust holes can be reduced and the flow passage cross-sectional area can be increased, so that the efficiency of the electric blower can be increased. Furthermore, since the occurrence of flow turbulence can be suppressed and the average flow velocity is reduced, turbulent noise can be reduced.
[0025]
Further, by forming the same configuration using the wall surface of the electric blower chamber of the vacuum cleaner main body, it is possible to provide a lightweight, high efficiency and low noise vacuum cleaner that does not require a motor housing.
[Brief description of the drawings]
FIG. 1 is an embodiment of an electric blower of the present invention.
FIG. 2 is a structure of a conventional electric blower.
FIG. 3 is a structure of a vacuum cleaner body relating to the present invention.
4 is a perspective view of the same product as FIG. 1. FIG.
FIG. 5 is another embodiment of the present invention.
6 is a perspective view of the same product as FIG. 5. FIG.
FIG. 7 is another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Blower, 2 ... Electric motor, 3 ... Housing, 3c ... Exhaust port, 4 ... Rotary shaft, 5 ... Rotor, 6 ... Stator coil, 7 ... Stator, 9 ... End bracket, 10 ... Static flow path part, 11 ... Diffuser , 12 ... Rotating impeller, 13 ... Blower case, 13a ... Airflow guide, 13b ... Air inlet, 14 ... Return guide, 15 ... Brush, 16 ... Static flow path part, 17 ... Radial-circumferential surface, 18 ... Free Space, 30 ... exhaust port, 50 ... stator core, 51 ... upper suspension member, 52 ... lower suspension member, 53 ... motor housing, 54 ... carbon brush mounting hole, 55 ... centrifugal impeller, 56 ... fan casing, 57 ... Fitting location, 60 ... End bracket, 61 ... Diffuser, 62 ... Return, 63 ... Exhaust hole, 64 ... Cooling air flow, 70 ... Stator core, 71 ... Motor housing, DESCRIPTION OF SYMBOLS 72 ... Concave part, 73 ... Convex part, 101 ... Intake air, 102 ... Diffuser inflow air, 104 ... Outflow inside housing, 105 ... Carbon brush, 106 ... Motor housing constriction part, 107 ... Motor housing bracket, 201 ... Vacuum cleaner main body longitudinal section Surface view, 202 ... Electric blower and vacuum cleaner of the present invention, 301 ... Lower case of vacuum cleaner body, 302 ... Upper case of vacuum cleaner body, 303 ... Dust collection lid, 304 ... Suction port, 305 ... Dust collection bag 306: Dust collection chamber, 307: Electric blower chamber, 308 ... Electric blower of known example, 309 ... Electric blower of the present invention, 310 ... Motor housing of the present invention, 311 ... Stator core, 312 ... Commutator, 313 ... Rotating shaft, 314: Support column, 315 ... Electric blower chamber wall surface, 316 ... Cooling air flow, 317 ... Exhaust hole, 318 ... Exhaust port of vacuum cleaner

Claims (3)

A rotating shaft, a driving armature rotor attached to the rotating shaft, a stator composed of coils provided on the outer periphery of the rotor, a stator core installed in the stator, and an air flow generation attached to the rotating shaft Centrifugal impeller, a diffuser disposed outside the centrifugal impeller, a return provided at a position facing the diffuser and a surface perpendicular to a rotation axis, and the centrifugal impeller, diffuser, return In an electric blower having a fan casing containing a motor housing including a rotor casing, a stator, and a stator core,
The outermost diameter of the motor housing is expanded in the radial direction toward the centrifugal impeller, and the motor housing is provided with at least two or more radial depressions distributed in the circumferential direction, depending on a part or all of the depressions. An electric blower characterized by fixing the stator core. An electric vacuum cleaner body composed of a lower case, an upper case and a dust collecting lid, a dust collecting chamber is formed inside the dust collecting lid, and an electric blower chamber is formed behind the dust collecting chamber through a filter. In the vacuum cleaner that houses the electric blower in the blower room,
The electric blower includes a rotating shaft, a driving armature rotor attached to the rotating shaft, a stator including a coil provided on an outer periphery of the rotor, a stator core installed in the stator, and the rotating shaft A centrifugal impeller for generating an airflow attached to the outer periphery, a diffuser disposed outside the centrifugal impeller, a return provided at a position facing the diffuser and a surface perpendicular to a rotation axis, and the centrifugal impeller It consists of a car, a diffuser, and a fan casing that contains the return.
The outermost diameter of the electric blower chamber wall surface including the rotor, stator, and stator core is expanded radially toward the centrifugal impeller, and the electric blower chamber wall surface is distributed in at least two radial directions distributed in the circumferential direction. An electric vacuum cleaner , wherein a recess is provided, and the electric blower chamber wall surface is used as a motor housing so as to fix the stator core by a part or all of the recess . An electric vacuum cleaner body composed of a lower case, an upper case and a dust collecting lid, a dust collecting chamber is formed inside the dust collecting lid, and an electric blower chamber is formed behind the dust collecting chamber through a filter. In the vacuum cleaner that houses the electric blower in the blower room,
The electric blower includes a rotating shaft, a driving armature rotor attached to the rotating shaft, a stator including a coil provided on an outer periphery of the rotor, a stator core installed in the stator, and the rotating shaft A centrifugal impeller for generating an airflow attached to the outer periphery, a diffuser disposed outside the centrifugal impeller, a return provided at a position facing the diffuser and a surface perpendicular to a rotation axis, and the centrifugal impeller A fan casing containing a car, a diffuser, and a return; and a motor housing containing the rotor, stator, and stator core; and the outermost diameter of the motor housing is expanded in a radial direction toward the centrifugal impeller. Is provided with at least two or more radial depressions distributed in the circumferential direction, and depending on part or all of the depressions Vacuum cleaner, characterized in that a structure for fixing the serial stator core.

Images