JP2022081860A - Electric blower and vacuum cleaner including the same - Google Patents

Abstract

To provide an electric blower which achieves high efficiency in a wide air volume range and is small and light-weight.SOLUTION: There are provided second axial flow diffuser blades 24 at the downstream of first axial flow diffuser blades 23. An impeller side motor housing 6 is provided at the inner side of the first axial flow diffuser blades 23 and an impeller opposing side motor housing 10 is provided at a position facing the impeller side motor housing. The two motor housings include openings 15, 20 directed in a radial direction on outer peripheral surfaces. An inner wall 2a of the impeller side housing 2 includes a passage extending in an axial direction. The passage extending in the axial direction extends to an axial end part of an inner wall 9a of the impeller opposing side housing 9 integrally formed with the second axial flow diffuser blades 24. An exhaust side end part of the inner wall 9a is located at the impeller side relative to an impeller opposing side end part of the outer peripheral surface of the impeller opposing side motor housing 10. The openings 20 are located at the impeller opposing side end part side of the outer peripheral surface of the impeller opposing side motor housing 10 relative to an exhaust side end part of the inner wall 2a.SELECTED DRAWING: Figure 1B

Description

The present invention relates to an electric blower and a vacuum cleaner including the electric blower.

Conventionally, the following Patent Document 1 is disclosed as an electric blower. Patent Document 1 states that "a motor (10) that rotates around a central axis (C) extending vertically and a motor that has a stator (24) arranged below the impeller (10) to rotate the impeller (10). The first flow path (5) is in the gap between the motor housing (21) that houses the (20) and the stator (24), and the motor housing (21) that houses the impeller (10) and the motor housing (21). The upper portion of the fan casing (2) covers the upper part of the impeller (10) and has an intake port (3) that opens in the vertical direction. An exhaust port (4) communicating with the intake port (3) via the first flow path (5) is provided in the lower portion, and the motor housing (21) has a stator (21) fixed to the inner surface of the motor housing (21). Below the upper surface of 24), an inlet (21a) that penetrates in the radial direction and communicates with the first flow path (5) is provided, and the motor housing (21) extends upward from the inlet (21a). A blower device (1) having a second flow path (6) communicated with a space above the stator (24). "

Japanese Unexamined Patent Publication No. 2018-105269

By the way, in an electric vacuum cleaner, the operating air volume changes greatly depending on the clogging of the filter due to dust and the operating conditions such as the material of the floor to be cleaned. Therefore, the electric vacuum cleaner is required to be an electric blower having a strong suction force in a wide air volume range. Further, from the viewpoint of usability of the electric vacuum cleaner, it is required to reduce the size and weight of the electric blower. Therefore, the heat dissipation area is reduced, the heat generation density inside the electric blower is increased, and it is necessary to improve the cooling performance of the motor and the bearing.

In addition, the diffuser with wings can perform excellent pressure recovery at the design point air volume, but at the non-design point air volume, the diffuser performance is improved due to the mismatch between the inlet angle of the diffuser blade and the inflow angle of the air flow into the diffuser. descend. Therefore, the suction force of the electric vacuum cleaner is high at the design point air volume, but may decrease at the non-design point air volume.

A vacuum cleaner driven by a battery (secondary battery) such as a cordless stick type or an autonomous traveling type has a small power consumption of an electric blower and a small maximum air volume due to the battery capacity. Therefore, there is a problem that the dust transporting capacity is lowered when the filter is clogged, and the suction power of the vacuum cleaner is lowered. Furthermore, vacuum cleaners driven by batteries (secondary batteries) such as cordless stick type or autonomous traveling type are required to be small and lightweight, and the electric blower mounted on the vacuum cleaner has a suction force in a wide air volume range. It is required to have both strong and small size.

As described above, Patent Document 1 describes "a fan casing (2) constituting a first flow path (5) in a gap between a motor housing (21) accommodating an impeller (10) and a motor (20). The upper part of the fan casing (2) covers the upper part of the impeller (10) and has an intake port (3) that opens in the vertical direction, and the lower part of the fan casing (2) has a first flow path (5). An exhaust port (4) communicating with the intake port (3) is provided, and the motor housing (21) has a diameter below the upper surface of the stator (24) fixed to the inner surface of the motor housing (21). An inflow port (21a) that penetrates in the direction and communicates with the first flow path (5) is provided, and the motor housing (21) extends upward from the inflow port (21a) and is a space above the stator (24). It has a second flow path (6) that communicates with. " That is, in Patent Document 1, the flow of the first flow path (5) is branched by the structure, flows into the second flow path (6), and is a bearing of a ball bearing on the fan side existing above the stator (24). It is shown that the flow flows in the vicinity of (26), and then the bearing (26) of the slide bearing on the anti-fan side is cooled and exhausted to the outside of the electric motor (motor 20) without merging with the first flow path. ..

The blower (1) of Patent Document 1 passes through an inlet (21a) through which the air volume of the first flow path (5) penetrates in the radial direction and communicates with the first flow path (5), and passes through a second flow path (6). ), The air volume in the first flow path (5) downstream from the inflow port (21a) communicating with the flow path pressure loss (resistance) decreases with respect to the air volume upstream from the inflow port (21a). ..

The diffuser with wings can perform excellent pressure recovery at the design point air volume, but if the air volume is lower than the design point air volume, the diffuser will be due to the mismatch between the inlet angle of the diffuser blade and the inflow angle of the air flow into the diffuser. Performance may be reduced and the suction power of the vacuum cleaner may be reduced. Further, since the second flow path (6) extending upward from the inflow port (21a) of the second flow path (6) and communicating with the space above the stator (24) is small, the flow path area is Is small, and since it flows while bending inside the motor (20), there is a concern that the pressure loss in the flow path will be large, the cooling air volume will decrease, the temperature inside the motor (motor 20) will rise, and the efficiency of the motor will decrease. ..

The present invention has been devised in view of the above-mentioned actual conditions in order to solve the above-mentioned problems, and an object of the present invention is to provide a highly efficient, compact and lightweight electric blower in a wide air volume range and an electric vacuum cleaner equipped with the electric blower. ..

In order to solve the above problems, the present invention has a first axial flow diffuser blade on the impeller side having blades in the circumferential direction downstream of the axial direction of the impeller, and a second one downstream of the first axial flow diffuser blade. An impeller side motor housing that has an axial flow diffuser blade and is located inside the impeller side housing that is integrated with the first axial flow diffuser blade in the radial direction, and an anti-blade at a position facing the impeller side motor housing. The impeller side motor housing and the anti-impeller side motor housing are provided with an electric motor having a vehicle side motor housing and having a stator and a rotor on the inner diameter side of the impeller side motor housing and the anti-impeller side motor housing. The outer peripheral surface has a plurality of openings facing in the radial direction in the circumferential direction, and the inner wall of the impeller side housing has a flow path extending in the axial direction including the outermost diameter in the radial direction of the impeller side motor housing. The flow path extending in the axial direction extends to the axial end of the inner wall of the anti-impeller side housing integrated with the second axial flow diffuser blade, and the exhaust side end of the inner wall of the anti-impeller side housing is said. Located on the impeller side from the end of the outer peripheral surface of the anti-impeller side motor housing on the anti-impeller side, the opening in the radial direction of the anti-impeller side motor housing is the exhaust of the inner wall of the anti-impeller side housing. It is characterized in that it is located closer to the end side of the outer peripheral surface of the anti-impeller side motor housing on the anti-impeller side than the end portion on the side.

According to the present invention, it is possible to provide an electric blower having high efficiency, small size and light weight in a wide air volume range, and suppressing a calorific value, and a vacuum cleaner provided with the electric blower.

The external view of the electric blower which concerns on 1st Embodiment of this invention. The vertical sectional view of the electric blower shown in FIG. 1A. The perspective view of the impeller of the 1st Embodiment. FIG. 2 is a cross-sectional view of the impeller shown in FIG. 2A. Front view of the impeller side housing 2 having the first axial flow diffuser blade 23 as viewed from the impeller side. The figure which looked at the impeller side housing 2 which has the 1st axis flow diffuser blade 23 from the impeller side. Partial cross-sectional view seen from the outer peripheral portion of the impeller side housing. Front view of the anti-impeller side housing 9 having the second axial flow diffuser blade 24 as viewed from the impeller side. FIG. 4A is a cross-sectional view of the second axial flow diffuser blade shown in FIG. 4A. Partial cross-sectional view seen from the outer periphery of the housing. The figure which looked at the motor of 1st Embodiment from the side. The vertical sectional view of the electric motor shown in FIG. 5A. The vertical sectional view of the electric blower in the 2nd Embodiment of this invention. The perspective view of the electric vacuum cleaner to which the electric blower according to 1st Embodiment of this invention is applied. FIG. 7 is a cross-sectional view taken along the line I of the vacuum cleaner body in the electric vacuum cleaner shown in FIG. 7.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
<< First Embodiment >>
FIG. 7 is a perspective view of the vacuum cleaner 300 to which the electric blower 200 according to the first embodiment of the present invention is applied.

FIG. 8 is a cross-sectional view taken along the line I of the vacuum cleaner body 100 in the vacuum cleaner 300 of the first embodiment. The vacuum cleaner 300 according to the first embodiment of the present invention will be described.

<Configuration of vacuum cleaner 300>
The electric vacuum cleaner 300 includes a vacuum cleaner main body 100, a holding portion 102 to which the vacuum cleaner main body 100 is attached, a grip portion 103 gripped by the user, and a mouthpiece 105 for sucking dust.

The battery unit 108 (see FIG. 8), which is the drive source of the vacuum cleaner 300, is charged using the charging stand 107 (see FIG. 7). The battery unit 108 is housed in the vacuum cleaner main body 100.

The vacuum cleaner main body 100 houses a dust collecting chamber 101 that collects dust and an electric blower 200 (see FIG. 8) that generates a suction airflow necessary for collecting dust.

A grip portion 103 is provided at one end of the holding portion 102. The grip portion 103 is provided with a switch portion 104 (see FIG. 7) for turning on / off the electric blower 200.

A mouthpiece 105 is attached to the other end of the holding portion 102. The mouthpiece 105 and the vacuum cleaner body 100 that generates a suction airflow are connected by a connecting portion 106.

When using the vacuum cleaner 300, the user "turns on" the switch portion 104 of the grip portion 103. Then, the operation of the electric blower 200 housed in the vacuum cleaner main body 100 is started, and a suction airflow is generated in the mouthpiece 105. Dust on the floor surface Y (see FIG. 7) is sucked from the mouthpiece 105 by the suction airflow. The sucked dust is collected in the dust collecting chamber 101 of the vacuum cleaner main body 100 through the connection portion 106.

<Vacuum cleaner body 100>
Next, the vacuum cleaner main body 100 will be described.

As shown in FIG. 8, an electric blower 200, a battery unit 108, a drive circuit 109, and a dust collecting chamber 101 are arranged inside the vacuum cleaner main body 100.

The battery unit 108 drives the electric blower 200. The electric blower 200 generates a suction force at the mouthpiece 105.

The vacuum cleaner main body 100 includes a main body grip portion 110 and a mouthpiece opening 111.

The user can grip the main body grip portion 110, remove the vacuum cleaner main body 100 from the holding portion 102, and use it as a handheld vacuum cleaner.

The main body switch unit 112 shown in FIG. 7 is a switch for turning on / off the electric blower 200 when the vacuum cleaner main body 100 is used as a handheld vacuum cleaner. The main body switch unit 112 can perform an "on / off" operation instead of the switch unit 104 even when the vacuum cleaner main body 100 is attached to the holding unit 102.

The electric vacuum cleaner 300 shown in FIGS. 7 and 8 shows a cordless vacuum cleaner in which the suction port opening 111 (see FIG. 9) and the connection portion 106 can be removed, but with a power cord not equipped with a battery. It may be a vacuum cleaner. Further, a stick-type cordless vacuum cleaner having an extension pipe or a hose between the dust collector and the suction port may be used.

<Electric blower 200>
1A is an external view of the electric blower 200 according to the first embodiment of the present invention, and FIG. 1B is a vertical sectional view of the electric blower 200 shown in FIG. 1A. Note that FIG. 1B shows a case where the annular anti-vibration rubber 21 is applied to the electric blower 200.

Next, the electric blower 200 will be described. In addition, in FIG. 1B, a typical air flow is shown by a solid line arrow α1 and a dotted line arrow α2 only on the left side of FIG. 1B.

The electric blower 200 is attached to the vacuum cleaner 300 shown in FIGS. 7 and 8 with the impeller 1 side facing the lower mouthpiece 105.

As shown in FIG. 1B, in the electric blower 200, the electric motor unit 202 is configured inside the blower unit 201 in the radial direction.

From the upstream of the suction air flow, the blower unit 201 has an impeller 1 which is a rotary blade, a first axial flow diffuser blade 23 on the impeller side (diffuser blade on the impeller side), and a second axial flow diffuser blade 24 (anti-impeller). Side diffuser wings) are installed. An exhaust port 32 is provided downstream of the second axial flow diffuser blade 24.

The impeller side housing 2 having the first axial flow diffuser blade 23 is attached to a screw portion provided in the impeller side motor housing 6.

The anti-impeller side housing 9 having the second axial flow diffuser blade 24 arranged on the anti-impeller side (the side far from the impeller 1) is arranged on the downstream side (exhaust port 32 side) of the impeller side housing 2. Has been done.

The electric motor unit 202 is located inside the impeller side housing 2 and the anti-impeller side housing 9 in the radial direction. The impeller side housing 2 is positioned so as to cover the impeller side motor housing 6, and the anti-impeller side housing 9 is located so as to cover a part of the anti-impeller side motor housing 10 in the axial direction. A part of the opening 20 provided in the radial direction of the outer peripheral portion of the side motor housing 10 is installed so as to be exposed.

The impeller side motor housing 6 has the same shape as the anti-impeller side motor housing 10, and has a plurality of openings 15 and 20 in the radial direction on the outer peripheral portion. The anti-impeller side motor housing 10 has an opening 34 in the axial direction. Further, the openings 15 and 20 facing the radial direction of the outer peripheral portion of each motor housing are arranged with six openings in the circumferential direction. Further, the opening 15 of the impeller side motor housing 6 and the opening 20 of the anti-impeller side motor housing 10 are installed so as not to overlap with the stator core 8 in the axial direction. Further, the openings 15 and 20 of each motor housing are arranged so as to overlap with the axial end portion of the coil in the axial direction. The radial openings of the motor housing are uniformly arranged in the circumferential direction, and the number of openings and the number of blades of the second axial flow diffuser blade 24 have the greatest common divisor of 3. That is, the same flow field can be introduced into the opening 20 at three locations in the circumferential direction, and the temperature distribution in the circumferential direction can be reduced. It is desirable that the greatest common divisor is higher than 1, 3 or more, or the same as the number of openings.

The impeller side motor housing 6 holds a bearing 11 on the impeller 1 side in the axial direction of the electric motor unit 202. The anti-impeller side motor housing 10 holds a bearing 12 on the anti-impeller side in the axial direction of the electric motor unit 202.

The second flow path 19 has an opening 20 in the radial direction of the anti-impeller side motor housing 10, an opening 15 inside the motor and the impeller side motor housing 6, and an outer peripheral portion and blades of the impeller side motor housing 6. It passes between the inner wall 2a of the vehicle-side housing.

A first flow path 18 passing through the impeller 1, the first axial flow diffuser blade 23, and the second axial flow diffuser blade 24 is provided on the side portion of the electric blower 200. The first flow path 18 is a flow path through which the air flow of the suction force in the mouthpiece 105 (see FIG. 7) flows.

The first flow path 18 and the second flow path 19 meet at the axial end portion 9c of the inner wall 9a of the anti-impeller side housing 9. The axial end portion 9c is located at a position substantially half of the axial dimension of the second axial flow diffuser blade 24. By merging the first flow path 18 and the second flow path 19 at the axial end portion 9c, a flow in the second flow path 19 is generated by the Venturi effect due to the main flow of the second axial flow diffuser blade 24. The cooling air is taken into the motor through the opening 20 of the motor housing 10 on the anti-impeller side and the opening 34 in the axial direction. As a result, the cooling performance of the motor unit 202 can be improved and the efficiency of the electric blower 200 can be improved in a wide operating range.

It should be noted that the axial end portion 9c may extend to approximately half or more of the axial dimension of the second axial flow diffuser blade 24 and may extend to the trailing edge of the blade, in order to generate cooling air due to the venturi effect. It is desirable that the wheel is located on the impeller side in the axial direction from the opening 20.

The second flow path 19 is located inside the first flow path 18 in the radial direction. Further, the opening of the motor housing 10 on the anti-impeller side is formed with an opening 34 in the axial direction and an opening 20 in the radial direction. By making the opening large, the air volume generated by the Bencheri effect can be increased, and the inside of the motor can be cooled more efficiently when passing through the second flow path 19.

Further, since the opening 20 of the anti-impeller side motor housing 10 is located inside the inner wall 9a of the anti-impeller side housing 9 in the radial direction, it becomes easy to secure the flow path area of the second flow path 19, and the electric motor. It can cool the inside more efficiently.

A part of the winding comes out from the opening 34 and is electrically connected to the drive circuit 109 (see FIG. 8). Here, the structure of the opening of the motor housing may be a square hole, a round hole, or a hole of another shape.

Further, in this embodiment, the ratio Rd / Rm of the outermost diameter Rm of the anti-impeller side motor housing 10 and the maximum flow path diameter Rd of the anti-impeller side housing 9 having the second axial flow diffuser blade 24 is about 1.5 or less. It is composed of.

In the impeller 1 shown in FIG. 1B, a metal sleeve 13 is covered with a hub plate 26 made of a thermoplastic resin. The impeller 1 is fixed by screwing a fixing nut to a female screw threaded on the end of the rotating shaft 5. Here, in the first embodiment, the case where the impeller 1 which is a rotary blade is fixed by providing a female screw at the end of the rotary shaft 5 and using a fixing nut is exemplified, but it may be fixed by press fitting. .. Further, although the impeller 1 shown in FIG. 1B shows a mixed flow type impeller, it may be a centrifugal type or an axial flow impeller.

<Motor unit 202>
Next, the configuration of the motor unit 202 of the first embodiment will be described.
5A is a side view of the motor unit 202, and FIG. 5B is a vertical sectional view of the motor shown in FIG. 5A. The motor unit 202 is provided with a rotor core 7 (rotor) and a stator core 8 arranged on the outer peripheral portion thereof.

The rotor core 7 is housed in two motor housings and fixed to the rotating shaft 5.

A coil (winding) 17 is wound around the winding frame portion of the stator core 8 (stator). The coil 17 is electrically connected to a drive circuit 109 (see FIG. 8) provided in the electric blower 200.

Although a copper wire is used for the coil, a smaller and lighter electric blower can be provided by using a wire rod made of a composite material using a copper material around the aluminum wire or the covering material of the aluminum wire.

The rotor core 7 has a rare earth-based bond magnet. Rare earth-based bonded magnets are made by mixing rare earth-based magnetic powder and an organic binder. As the rare earth-based bond magnet, for example, a samarium iron-nitrogen magnet, a neodymium magnet, or the like can be used. The rotor core 7 is integrally molded or fixed to the rotating shaft 5. The operating rotation speed of the electric blower 200 is 50,000 to 200,000 cycle / min.

In the present embodiment, a permanent magnet is used for the rotor core 7, but the present invention is not limited to this, and a reluctance motor or the like, which is a kind of non-commutator motor, may be used.

A bearing 11 is provided between the impeller 1 and the rotor core 7. The bearing 12 is provided on the opposite side of the bearing 11 in the rotation axis 5 direction with respect to the rotor core 7. The bearing 11 on one side of the rotating shaft 5 and the bearing 12 on the other side rotatably support the rotating shaft 5.

The impeller side motor housing 6 on the side closer to the impeller 1 supports the bearing 11, and the anti-impeller side motor housing 10 on the side farther from the impeller 1 supports the bearing 12. The motor housing is made of metal, and by using an aluminum alloy as the material, it is possible to improve the cooling performance and reduce the weight by heat conduction. The motor housing may be made of resin instead of metal, and in the case of resin, cooling of the bearing can be promoted by providing a metal support between the bearing and the motor housing. Further, the motor housing may be made of an aluminum alloy material or a steel material.

Spacers 16 for axially positioning the bearings are installed on the rotor core 7 side of the bearings 11 and 12.

Further, to adjust the unbalance amount of the rotating body, the unbalance amount of the rotating body is minimized by installing a magnet cover 14 provided on the outer peripheral portion of the magnet and a resin balance adjusting material at the end of the magnet. There is. As a result, the noise and vibration of the electric blower 200 are reduced.

Further, the impeller side motor housing 6 on the side closer to the impeller 1 and the anti-impeller side motor housing 10 on the side farther from the impeller 1 have the same shape, and the stator core 8 is installed so as to sandwich it in the axial direction. The outer peripheral portion of the stator core 8 and the inner wall of the motor housing are overlapped in the axial direction and assembled by bonding or press-fitting. The stator core 8 is in contact with two motor housings and has an exposed portion 8a exposed from the motor housing at a substantially central position of the stator core 8. By adopting such a stator core 8 and a motor housing structure, heat generation of the stator core 8 is cooled by heat conduction of the impeller side motor housing 6 and the anti-impeller side motor housing 10 and forced cooling in the exposed portion 8a. This enables high heat generation density and low loss cooling. The circumferential positions of the plurality of openings 15 and 20 provided in the circumferential direction of the motor housing may be the same circumferential position or different circumferential positions. By using a motor housing with the same structure, both cost reduction and improved cooling performance are achieved.

The circumferential positions of the first axial flow diffuser blade 23 and the second axial flow diffuser blade 24 will be described. The outer peripheral portion of the impeller side housing 2 is provided with protrusions 35 at three locations in the circumferential direction. The claw portion 22 provided on the outer peripheral portion of the anti-impeller side housing 9 on the side far from the impeller 1 and the protrusion 35 of the impeller side housing 2 are fitted and connected to each other. Further, the number of blades of the first axial flow diffuser blade 23 and the number of the claws 22 at the end of the anti-impeller side housing 9 and the number of protrusions 35 of the impeller side housing 2 are 3 for the number of blades and the protrusion 35. It consists of the greatest common divisor of. In this way, the circumferential positions of the first axial flow diffuser blade 23 and the second axial flow diffuser blade 24 are set to predetermined circumferential positions in order to improve mass productivity. The number of blades and the greatest common divisor of the protrusions 35 may be higher than 1, but if the number of protrusions is used, the position of each diffuser blade in the circumferential direction is determined, and mass productivity at the time of assembly is the best.

In the fan casing 3 covering the impeller 1 shown in FIG. 1B, the lower end portion 3a of the fan casing is inserted into the fitting portion 28 of the impeller side housing 2, and the fan casing 3 is adhesively fixed to the impeller side housing 2. Further, the anti-vibration rubber 21 shown in FIG. 1B is installed in the installation portion of the vacuum cleaner main body 100 of the fan casing 3. By providing the anti-vibration rubber 21, the vibration of the electric blower 200 is suppressed, and the air leakage between the fan casing 3 and the installation portion of the vacuum cleaner main body 100 is prevented to reduce noise and improve efficiency. I'm trying.

Here, the impeller side housing 2 is assembled and fixed from the impeller side to a screw portion provided in the impeller side motor housing 6 of the separately assembled motor. Further, the impeller 1 is inserted into the rotating shaft 5 of the electric motor and fixed with screws. The fan casing 3 is inserted into the fitting portion 28 of the impeller side housing 2 and adhered with an adhesive. After that, the motor assembly integrated with the fan casing is assembled to the claw portion of the anti-impeller side housing 9, and is adhered by flowing an adhesive to the housing fitting portion 37. That is, all the assembly of the motor and the blower is operated and assembled from the upstream direction of the impeller, so that the assemblability at the time of mass production can be improved.

Further, the fitting portion 28 between the fan casing 3 and the impeller side housing 2 is provided with a slight gap in the axial direction and the circumferential direction so as to allow misalignment of the impeller, and can be adjusted at the time of assembly. By adjusting the shaft cores of the impeller 1 and the fan casing 3, it is possible to improve efficiency and mass productivity.

Here, among the motors excluding the rotary shaft 5, the motor axial length Lm connecting the upper end and the lower end of the motor housing forming the outer peripheral portion is the diffuser axial length Ld from the impeller outlet to the exhaust port. It has substantially the same length and is shorter than the blower axial length Lf from the suction port to the exhaust port of the blower. The ratio of the blower axial length Lf to the motor axial length Lm is formed to be about 3: 2, and the blower axial length Lf and the motor axial length Lm are installed so as to overlap in the axial direction. By realizing this configuration, by utilizing the Venturi effect at the diffuser outlet, it is possible to introduce the flow of cooling air into the motor with low loss, and it is possible to realize a compact and highly efficient electric blower. It will be possible.

Further, in order to maximize the Venturi effect generated by the flow of the first flow path, which is a feature of the present application, it is desirable to reduce the difference in the maximum diameter between the first flow path and the second flow path. In this configuration, the maximum diameter Rd of the flow path of the anti-impeller side housing 9 having the second axial flow diffuser blade (the motor housing side of the outer wall 9b of the anti-impeller side housing 9) is used to take in the cooling air using the venturi effect. Radius) is formed at about 1.5 times the outer diameter Rm of the outer peripheral portion of the motor housing. The ratio of the maximum diameter Rd of the flow path of the anti-impeller side housing 9 having the second axial flow diffuser blade 24 to the outer diameter Rm of the outer peripheral portion of the motor housing is smaller than about 1.5 times, the more efficient the Venturi effect is. It is possible to realize a compact and highly efficient electric blower.

Although the configuration having the second axial flow diffuser blade is described in this embodiment, an annular flow path may be used regardless of the presence or absence of the second axial flow diffuser blade in order to obtain the Venturi effect.

At the design point, the first axial flow diffuser blade 23 substantially matches the flow flowing out from the impeller 1 with the blade inlet angle to reduce the pressure loss. As a result, the first axial flow diffuser blade 23 reduces the rotational velocity component of the flow, thereby enhancing the diffuser effect and improving the blower efficiency. Further, the second axial flow diffuser blade 24 installed on the downstream side of the first axial flow diffuser blade 23 further reduces the rotational velocity component of the flow flowing out from the first axial flow diffuser blade 23. As a result, the deceleration of the air flow in the direction of the rotating shaft 5 can be enhanced, and the efficiency of the blower can be further improved.

<Air flow in the electric blower 200>
Next, the flow of air in the electric blower 200 will be described.

When the motor unit 202 shown in FIG. 1B is driven to rotate the impeller 1, air flows in from the air suction port 4 of the fan casing 3 and flows into the impeller 1. In the case of a mixed flow type impeller, the inflowing air is boosted in the impeller 1 while giving a radial component to the flow sucked in from the direction of the rotating shaft 5 to generate a flow inclined from the direction of the rotating shaft 5. .. In this way, at the impeller outlet 1a, a flow having a rotation direction component and a direction component of the rotation shaft 5 is formed and flows out from the impeller 1.

The air flow flowing out from the impeller 1 flows along the blades (23, 24) when passing through the first axial flow diffuser blade 23 and the second axial flow diffuser blade 24, so that the speed in the rotational direction of the flow The ingredients are reduced. Further, the axial end portion 9c (lower end portion of the inner wall) of the anti-impeller side housing 9 is located upstream of the trailing edge 24d of the second axial flow diffuser blade 24 (second from the inner wall of the second axial flow diffuser blade 24). By projecting the trailing edge 24d of the axial flow diffuser blade 24), the flow path expands inward in the radial direction in the latter half of the second axial flow diffuser blade 24. As a result, a radial inward flow is generated in the latter half of the second axial flow diffuser blade 24, and the air is exhausted (the flow expands in the direction without the inner wall). This radial inward flow promotes the flow into the opening 20 of the anti-impeller side motor housing 10. The first flow path 18 is a flow path from the air suction port 4 of the fan casing 3 to the exhaust port 32 of the anti-impeller side housing 9 as shown by the solid line arrow α1 in FIG. 1B.

Since the outlet wind speed of the second axial flow diffuser blade 24 is high in the second flow path 19, a flow toward the outlet of the second axial flow diffuser blade 24 is generated in the second flow path 19 due to the Venturi effect. The flow toward the outlet of the second axial flow diffuser blade 24 in the second flow path 19 sucks the flow from the opening 20 of the motor housing 10 on the anti-impeller side, and surrounds the vicinity of the bearing 12 on the anti-impeller side inside the motor. By passing between the coils 17 arranged in the direction, the bearing 12 on the anti-impeller side and the coil are cooled. Further, the flow passing between the coils passes around the bearing 11 on the impeller side, passes through the opening 15 of the motor housing 6 on the impeller side, and reaches the inner wall 2a of the motor housing 6 on the impeller side and the housing 2 on the impeller side. The radial gap is directed downstream in the axial direction (exit of the second axial flow diffuser blade 24) and joins the first flow path 18. The stator core 8 is cooled with low loss by allowing cooling air to pass through a radial gap between the impeller side motor housing 6 and the inner wall 2a of the impeller side housing 2.

By merging the first flow path and the second flow path in the vicinity of the second axial flow diffuser blade 24, the Venturi effect is efficiently utilized and the inside of the motor can be cooled. That is, since the flow direction is not changed by the structure when the cooling air of the motor is taken in, the efficiency of the blower can be maintained high even at a non-design point, and the efficiency can be improved in a wide operating range.

<Blower section 201>
Next, the configuration of the blower unit 201 of the first embodiment will be described.

FIG. 2A is a perspective view of the impeller 1 of the first embodiment, and FIG. 2B is a cross-sectional view of the impeller 1. 3A is a front view of the impeller side housing 2 having the first axial flow diffuser blade 23 as viewed from the impeller side, FIG. 3B is a vertical sectional view, and FIG. 3C is a view from the outer peripheral portion of the impeller side housing. It is a partial sectional view. 4A is a front view of the anti-impeller side housing 9 having the second axial flow diffuser blade 24 as viewed from the impeller side, and FIG. 4B is a cross-sectional view of the second axial flow diffuser blade shown in FIG. 4A, FIG. 4C. Is a partial cross-sectional view seen from the outer peripheral portion of the housing. 5A is an external view of the motor unit 202 as viewed from the side, and FIG. 5B is a vertical sectional view. Note that FIGS. 3C and 4C show partial cross-sectional views in which the shroud is removed in order to show the shape of the diffuser blades (23, 24).

<Imperial wheel 1>
First, the impeller 1 of the rotary blade according to the embodiment of the present invention will be described with reference to FIGS. 2A and 2B.

The impeller 1 includes a hub plate 26 and a plurality of blades 27. The hub plate 26 and the blade 27 are integrally molded with engineering plastic or thermoplastic resin.

A convex portion 26a (see FIG. 2B) is provided on the back surface side of the hub plate 26. By rotating the impeller 1 and scraping the convex portion 26a, the balance of the impeller 1 can be corrected. As a result, the unbalance amount of the impeller 1 can be reduced, and vibration and noise can be reduced.

Further, a metal sleeve 13 (see FIG. 2B) is provided on the back surface side of the hub plate 26 as an integrally molded product. By using the sleeve 13, it is possible to reduce the variation in the fitting gap between the shaft and the impeller that occurs when the sleeve is not used, and it is possible to reduce vibration and noise by reducing the imbalance of the impeller. Further, by installing the metal sleeve 13 on the boss portion of the impeller, the heat generated by the bearing 11 is transferred to the sleeve, so that the cooling performance of the bearing 11 due to the rotation of the sleeve 13 can be promoted. ..

The resin of the impeller 1 and the resin of the fan casing 3 improve the slidability of the resin on the impeller side when removing burrs during impeller molding (by scraping the impeller) during assembly. It is possible to minimize the gap between the fan casing 3 and the fan casing 3 by performing the familiar operation.

On the other hand, when the amount of deformation of the blade due to centrifugal stress during operation of the impeller 1 is large, a material having a small Young's modulus is used for the fan casing 3 so that the resin of the fan casing 3 is scraped. The gap between the vehicle 1 and the fan casing 3 can be minimized, and a highly efficient electric blower can be applied.

The impeller 1 is a mixed flow impeller in which the boss curved surface 29a is inclined toward the outer peripheral portion of the impeller in the direction of the rotating shaft 5 (downward in FIG. 2B). 2A and 2B show the impeller 1 of the open type mixed flow impeller without a shroud plate, but a centrifugal impeller may be used regardless of the presence or absence of the shroud plate.

Next, the blower 201 of the first embodiment will be described.

As shown in FIG. 1B, in the blower 201 of the example, 15 first axial flow diffuser blades 23 arranged at equal intervals in the circumferential direction are installed on the downstream side in the axial direction of the impeller 1. The first axial flow diffuser blade 23 is provided between the inner wall 2a and the outer wall 2b of the impeller side housing 2, and is integrally molded with the impeller side housing 2. The second axial flow diffuser blade 24 is installed between the inner wall 9a and the outer wall 9b of the anti-impeller side housing 9, and is integrally molded with the anti-impeller side housing 9. The number of blades of the second axial flow diffuser blade 24 is the same as that of the first axial flow diffuser blade 23.

The circumferential positions of the shroud-side (outer peripheral side) trailing edge 23d of the first axial flow diffuser blade 23 and the shroud-side (outer peripheral side) leading edge 24c (see FIG. 4C) of the second axial flow diffuser blade 24 are shown in FIG. It is almost the same in the circumferential direction.

The efficiency on the low air volume side can be improved by substantially matching the circumferential positions of the trailing edge 23d of the first axial flow diffuser blade 23 and the leading edge 24c of the second axial flow diffuser blade 24. In order to improve the efficiency on the large air volume side, 15 to 50% of the (23, 24) blade-to-blade pitch (360 / Zd) is preferable.

As shown in FIG. 1B, the inner wall (hub) 2a of the first axial flow diffuser blade 23 and the inner wall (hub) 9a of the second axial flow diffuser blade 24 substantially coincide with each other. Here, it is desirable that the inner wall 2a of the first axial flow diffuser blade 23 and the inner wall 9a of the second axial flow diffuser blade 24 are flush with each other. For example, when the inner wall 9a of the anti-impeller side housing 9 after merging is large and the diameter of the hub surface is large and protrudes into the flow path, the loss in the first axial flow diffuser blade 23 and the second axial flow diffuser blade 24 increases. Because.

As shown in FIG. 1B, the inner wall 2a of the impeller side housing 2 and the inner wall 9a of the anti-impeller side housing 9 are installed without a gap in the axial direction.

The outer wall 2b of the impeller side housing 2 and the outer wall 9b of the anti-impeller side housing 9 are centered by the housing fitting portion 37, and the claw portion 22 on the outer peripheral portion of the anti-impeller side housing 9 is used in the circumferential direction. By fixing and adhesively fixing, the structure is easy to assemble, and mass productivity is improved.

The shape of the first axial flow diffuser blade 23 shown in FIGS. 3A to 3C in the height direction is inclined toward the anti-impeller side (the side away from the impeller 1) from the inner wall 2a to the outer wall 2b of the impeller side housing 2. (See FIG. 1B), from the vicinity of the center in the radial direction to the outer peripheral portion, it has an inclination returning to the upstream in the direction of the rotation axis 5 and is curved in the height direction.

As shown in FIG. 3C, the chord length on the shroud side of the first axial flow diffuser blade 23 (the line connecting the leading edge 23c and the trailing edge 23d) is the chord length on the hub side (inner wall 2a side). Longer than. Since the chord length on the shroud side has a high wind speed on the shroud side at the exit of the impeller 1, a gentle shape is used to suppress loss and improve efficiency. Further, by bending the first flow diffuser blade 23 in the height direction, the blade surface (the surface of the first axial flow diffuser blade 23) and the hub surface (inner wall 2a) on the hub side (inner wall 2a side) of the diffuser are generated. The next flow can be suppressed. Therefore, peeling of the inside of the diffuser (the blade surface and the inner wall 2a on the inner wall 2a side of the first axial flow diffuser blade 23) can be suppressed, and high efficiency can be achieved.

As shown in FIG. 4, the second axial flow diffuser blade 24 has a thicker blade thickness (blade thickness on the trailing edge side of the blade) toward the exhaust port 32, and the blade thickness of the first axial flow diffuser blade 23 ( (See Fig. 3) Thicker.

The chord length of the second axial flow diffuser blade 24 shown in FIG. 4 is substantially the same as the chord length on the shroud side of the first axial flow diffuser blade 23. By increasing the chord length of the second axial flow diffuser blade 24 and increasing the blade thickness toward the trailing edge of the second axial flow diffuser blade 24 as shown in FIG. 4C, the deceleration of the flow can be moderated. , The static pressure recovery can be enhanced and the efficiency can be improved.

Here, the shapes of the first axial flow diffuser blade 23 and the second axial flow diffuser blade 24 will be described.

The first axial flow diffuser blade 23 (diffuser blade on the impeller side) and the second axial flow diffuser blade 24 (diffuser blade on the anti-impeller side) have a chord length (for example, the first axial flow diffuser blade 23) shown in FIG. It has a blade shape with a solidity smaller than 1 divided by the distance along the circumferential direction of the blade mounting interval (the straight length connecting the leading edge 23c to the trailing edge 23d). If the solidity is smaller than 1, it can be manufactured with a mold structure that is molded in the direction of the rotating shaft 5, and high efficiency and productivity can be improved.

Further, the axial end portion 9c (lower end portion of the inner wall) of the second axial flow diffuser blade 24 is located upstream from the trailing edge of the second axial flow diffuser blade 24 (second from the inner wall of the second axial flow diffuser blade 24). (Protruding the trailing edge of the axial flow diffuser blade 24) causes the flow path to expand inward in the radial direction in the latter half of the second axial flow diffuser blade 24, thereby generating an inward radial flow and being exhausted. To. As a result, the flow of the motor housing 10 on the anti-impeller side into the opening 20 is promoted, and the cooling performance is improved.

The axial position of the trailing edge 24d of the second axial flow diffuser blade 24 is located between the axial direction of the radial opening 20 of the anti-impeller side motor housing 10. As a result, the deceleration of the flow in the rotational direction by the second axial flow diffuser blade can be increased to increase the static pressure, and the rotation by the blade can generate an inward flow in the radial direction toward the opening. Can be improved.

That is, the electric blower 200 of the first embodiment can maintain high efficiency in a wide operating range. Therefore, it is possible to provide the vacuum cleaner 300 (see FIG. 7) having a high suction power in a wide range.

In the first embodiment, as an example, the opening of the anti-impeller side motor housing 10 shown in FIG. 1B has an opening 20 in the radial direction and an opening 34 in the axial direction, but either one direction may be used, and the opening in the radial direction may be used. It may be an inclined opening that is compatible with both the axial direction and the axial direction.

The electric blower 200 of the first embodiment described above has a first axial flow diffuser blade on the impeller side having blades in the circumferential direction downstream of the axial direction of the impeller, and a downstream of the first axial flow diffuser blade. The impeller side motor housing located inside the impeller side housing that has the second axial flow diffuser blade and is integrated with the first axial flow diffuser blade in the radial direction, and the position facing the impeller side motor housing. It has an anti-impeller side motor housing, includes an impeller side motor housing and an electric motor having a stator and a rotor on the inner diameter side of the anti-impeller side motor housing, and has the impeller side motor housing and the anti-impeller side motor. The housing has a plurality of openings facing the radial direction on the outer peripheral surface in the circumferential direction, and the inner wall of the impeller side housing is a flow path extending in the axial direction including the outermost diameter in the radial direction of the impeller side motor housing. The flow path extending in the axial direction extends to the axial end of the inner wall of the anti-impeller side housing integrated with the second axial flow diffuser blade, and extends to the exhaust side end of the inner wall of the anti-impeller side housing. Is located on the impeller side from the end of the outer peripheral surface of the anti-impeller side motor housing on the anti-impeller side, and the radial opening of the anti-impeller side motor housing is the inner wall of the anti-impeller side housing. It is characterized in that it is located on the end side of the outer peripheral surface of the anti-impeller side motor housing on the anti-impeller side from the end portion on the exhaust side of the motor housing.

This makes it possible to provide a compact and lightweight electric blower 200 with high efficiency in a wide air volume range. Therefore, it is possible to obtain a vacuum cleaner 300 that is compact and has an improved suction force in a wide air volume range by cooling the stator core 8, the coil 17, and the bearings 11 and 12 of the motor unit 202.

<< Second Embodiment >>
Next, the second embodiment will be described with reference to FIG.

FIG. 6 is a vertical sectional view of the electric blower 200 according to the second embodiment of the present invention.

Unlike the electric blower 200 of the first embodiment, the electric blower 200 of the second embodiment has a second flow path 19 passing through an axial opening 33 of the impeller side motor housing 6, and the impeller side housing 2 and blades. It passes through the axial gap flow path 30 formed by the vehicle-side motor housing 6. Further, the cooling air that has passed through the axial clearance flow path 30 passes through the annular flow path 38 formed by the radial clearance between the impeller side motor housing 6 and the impeller side housing 2. The flow through the annular flow path passes through the connecting gap 31 connected between the first axial flow diffuser blade 23 and the second axial flow diffuser blade 24, and joins the second axial flow diffuser blade 24.

Since the electric blower 200 has the same basic configuration as that of the first embodiment, the same reference numerals are used for the same elements, and the description thereof will be omitted.

The flow of the second flow path 19 including the axial gap flow path 30, the annular flow path 38, and the connecting gap 31 has a low static pressure due to the high wind speed at the inlet of the second axial flow diffuser blade 24, resulting in a Venturi effect. As a result, a flow is generated from the inside of the motor through the connecting gap 31 toward the inlet of the second axial flow diffuser blade 24. The flow through the connecting gap 31 flows into the motor from the opening 20 to the opening 34 of the anti-impeller side motor housing 10, passes through the inside of the motor, and passes through the axial opening 33 of the impeller side motor housing 6. It passes through the axial gap flow path 30 between the housing 2 and the impeller side motor housing 6. After that, the cooling air that has passed through the axial clearance flow path 30 passes through the radial clearance (annular flow path 38) between the impeller side motor housing 6 and the impeller side housing 2, and passes through the first axial flow diffuser blade 23 and the second. It passes through the connecting gap 31 connected between the axial flow diffuser blades 24 and joins the second axial flow diffuser blade 24.

The flow of the second flow path 19 is sucked into the inside of the motor unit 202 to cool the bearing 12 on the anti-impeller side. Further, the flow of the second flow path flows on the outer peripheral side of the stator core 8, thereby cooling the stator core 8 and the winding, cooling the bearing 11 on the impeller side, and flowing into the connecting gap 31.

In addition, the second flow path configuration without the axial gap flow path shown in the first embodiment may be used in combination. Even in that case, the cooling air can pass through the radial opening 15 of the impeller side motor housing 6 and generate an amount of air flowing through the connecting gap 31, so that the motor can be cooled.

Further, the connecting gap 31 is formed by the inner wall 2a of the impeller side housing 2 and the anti-impeller side housing 9. The connecting gap 31 is inclined toward the exhaust side in the axial direction from the outer peripheral portion of the stator core 8 toward the second axial flow diffuser blade 24. As a result, the air flow flowing through the connecting gap 31 can smoothly join the air flow flowing through the first flow path 18, and cooling and high efficiency can be achieved.
The flow flowing from the connecting gap 31 to the first flow path 18 merges with the flow boosted by the impeller 1, flows to the second axial flow diffuser blade 24, and is exhausted from the exhaust port 32. The air volume passing through the second axial flow diffuser blade 24 is a combination of the air volume passing through the first axial flow diffuser blade 23 from the impeller 1 and the air volume flowing through the connecting gap 31 from the second flow path 19, and the electric blower 200. It becomes the maximum air volume inside.

The second axial flow diffuser blade 24 tends to generate a trailing vortex at the trailing edge of the first axial flow diffuser blade 23 at a non-design point where the air volume is small, and the inlet flow of the second axial flow diffuser blade 24 tends to be complicated. .. However, in the second axial flow diffuser blade 24 having the present configuration, the air volume from the connecting gap 31 merges with the first axial flow diffuser blade 23 and flows into the second axial flow diffuser blade 24.

As a result, the air volume inside the second axial flow diffuser blade 24 increases even at the non-design point. Therefore, the internal peeling of the second axial flow diffuser blade 24 is suppressed, and the blower efficiency is improved. The air volume from the opening 20 of the motor housing 10 on the anti-impeller side toward the connecting gap 31 flows more on the large air volume side where the air volume at the outlet of the first axial flow diffuser blade 23 increases. Therefore, in this configuration, the efficiency of the blower on the large air volume side can be improved, and the efficiency can be improved in a wide operating range.

According to the electric blower 200 of the second embodiment described above, the impeller side and the anti-impeller so as to expose the rotating rotor, the stator core and coil on the outer peripheral portion of the rotor, and a part of the outer peripheral portion of the stator core. The motor has a motor having a motor housing installed from both sides, a first axial flow diffuser blade having blades in the circumferential direction downstream of the impeller axial direction, and a blower having a second axial flow diffuser blade. Is formed in a separate assembly from the blower, and the impeller side housing integrated with the first axial flow diffuser blade is fixed to the impeller side motor housing and upstream in the major axis direction of the impeller side motor housing. The anti-impeller side housing having the second axial flow diffuser blade is arranged so as to cover the circumference of the impeller side motor housing from to the substantially center position, and the anti-impeller side housing having the second axial flow diffuser blade is substantially downstream from the center in the long axis direction of the impeller side motor housing. The two motor housings are arranged so as to cover the anti-impeller side motor housing, and the two motor housings have a plurality of openings installed in the radial direction, and the inner wall of the impeller side housing is radially different from the motor housing. The motor housing on the anti-impeller side has a gap, the opening of the motor housing on the anti-impeller side is located downstream of the second axial flow diffuser blade, the motor housing on the impeller side has an opening in the axial direction, and the motor housing on the impeller side has an opening. It has an electric blower having a gap in the axial direction between the impeller and the impeller side housing and having a connecting flow path connected between the first axial flow diffuser blade and the second axial flow diffuser blade.

This makes it possible to provide a compact and lightweight electric blower 200 with high efficiency in a wide air volume range. Therefore, it is possible to obtain a vacuum cleaner 300 that is compact and has an improved suction force in a wide air volume range by cooling the stator core (8) and the bearing 11 of the motor unit 202.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the configurations described. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

1 Impeller 2 Impeller side housing 2a Inner wall of impeller side housing (first axial flow diffuser)
2b Outer wall of impeller side housing (first axial flow diffuser)
3 Fan casing 3a Lower end of fan casing 4 Air suction port (suction port)
5 Rotating axis (axis)
6 Impeller side motor housing 7 Rotor core (rotor)
8 Stator core (stator)
9 Anti-impeller side housing 9a Inner wall of anti-impeller side housing (hub surface of second axial flow diffuser blade)
9b Outer wall of the anti-impeller side housing (shroud surface of the second axial flow diffuser blade)
9c Axial end of the anti-impeller side housing 10 Anti-impeller side motor housing 11 Bearing (bearing on the impeller side)
12 Bearings (bearings on the anti-impeller side)
13 Sleeve 14 Magnet cover 15 Opening (motor housing opening on the impeller side)
16 Spacer 17 Coil 18 First flow path 19 Second flow path 20 Opening (opening of motor housing on the anti-impeller side)
21 Anti-vibration rubber 22 Claws 23 First axial flow diffuser blade (diffuser blade on the impeller side)
24 Second axle flow diffuser blade (anti-impeller side diffuser blade)
26 Impeller hub plate 27 Blade 28 Fitting part 29 Impeller boss 30 Axial gap flow path 31 Connection gap 32 Exhaust port 33 Axial opening of impeller side motor housing 34 Axial opening of anti-impeller side motor housing Part 35 Protrusion part 36 Fastening part with motor 37 Housing fitting part 38 Circular flow path 200 Electric blower 201 Blower part 202 Electric part 300 Electric vacuum cleaner

Claims (6)

The first axial flow diffuser blade on the impeller side, which has blades in the circumferential direction downstream in the axial direction of the impeller,
A second axial flow diffuser blade is provided downstream of the first axial flow diffuser blade.
The impeller side motor housing located inside the impeller side housing integrated with the first axial flow diffuser blade in the radial direction, and the impeller side motor housing.
The anti-impeller side motor housing is held at a position facing the impeller side motor housing.
An electric motor having a stator and a rotor on the inner diameter side of the impeller side motor housing and the anti-impeller side motor housing is provided.
The impeller side motor housing and the anti-impeller side motor housing have a plurality of openings facing in the radial direction on the outer peripheral surface in the circumferential direction.
The inner wall of the impeller-side housing has a flow path extending in the axial direction, which is the outermost diameter in the radial direction of the impeller-side motor housing.
The axially extending flow path extends to the axial end of the inner wall of the anti-impeller side housing integrated with the second axial flow diffuser blade.
The exhaust-side end of the inner wall of the anti-impeller side housing is located on the impeller side from the anti-impeller side end of the outer peripheral surface of the anti-impeller side motor housing.
The opening in the radial direction of the anti-impeller side motor housing is located on the anti-impeller side end side of the outer peripheral surface of the anti-impeller side motor housing from the exhaust side end portion of the inner wall of the anti-impeller side housing. An electric blower characterized by being located in. The first axial flow diffuser blade on the impeller side having blades in the circumferential direction downstream of the axial flow impeller of the oblique flow impeller, and the second axial flow diffuser blade having the second axial flow diffuser blade downstream of the first axial flow diffuser blade.
The impeller side motor housing located inside the impeller side housing integrated with the first axial flow diffuser blade in the radial direction, and the impeller side motor housing.
The anti-impeller side housing integrated with the second axial flow diffuser blade overlaps a part of the anti-impeller side motor housing in the axial direction at a position facing the impeller side motor housing.
An electric motor having a stator and a rotor on the inner diameter side of the impeller side motor housing and the anti-impeller side motor housing is provided.
The inner wall of the impeller side housing and the inner wall of the anti-impeller side housing form a flow path toward the leading edge of the second axial flow diffuser blade and radially outward and axially inclined.
The impeller side motor housing and the anti-impeller side motor housing are provided with a plurality of radial openings on the outer peripheral surface in the circumferential direction.
The inner wall of the impeller-side housing has a flow path extending in the axial direction, which is the outermost diameter in the radial direction of the impeller-side motor housing.
The flow path extending in the axial direction has a second flow path connected to the inclined flow path, and has a second flow path.
The second flow path merges with the first flow path passing through the first axial flow diffuser blade.
An electric blower characterized in that the radial opening of the anti-impeller side motor housing is located downstream of the inclined flow path. The impeller side motor housing and the anti-impeller side motor housing are provided with a plurality of openings facing in the radial direction and openings facing in the axial direction on the outer peripheral surface in the circumferential direction.
The inner wall of the housing integrated with the first axial flow diffuser blade includes a flow path extending in the radial direction formed at the impeller side end portion of the impeller side motor housing.
The electric blower according to claim 1 or 2, which comprises the outermost diameter in the radial direction of the impeller-side motor housing, and has a flow path that is continuous with the radial flow path and extends in the axial direction. The invention according to any one of claims 1 to 3, wherein the trailing edge of the second axial flow diffuser is installed so as to overlap with each other in the axial direction of the radial opening of the anti-impeller side housing. Electric blower. The feature is that the ratio Rd / Rm of the outermost diameter Rm of the anti-impeller side motor housing and the maximum flow path diameter Rd of the anti-impeller side housing having the second axial flow diffuser blade is about 1.5 or less. The electric blower according to any one of claims 1 to 4. An electric vacuum cleaner provided with the electric blower according to any one of claims 1 to 5.

Images