Electric air blower and vacuum cleaner

Abstract

To provide an electric air blower that is compact and lightweight, and has a high air volume and a high output.SOLUTION: An electric air blower comprises a motor, a first impeller, a second impeller, and an outer component. The motor comprises a rotor comprising a shaft and a core, a stator, and a motor housing for housing the core and the stator. The outer component surrounds the first impeller and the second impeller, and internally forms a first flow passage and a second flow passage. The first flow passage and the second flow passage discharge gas having flowed in from one side in an axial direction, to the other side in the axial direction. The first flow passage is formed so as to pass through a space in which the first impeller is housed. The second flow passage is formed so as to pass through a space in which the second impeller is housed. The first flow passage and the second flow passage are not spatially continuous with each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to electric blowers and vacuum cleaners. [Background technology]

[0002] Due to its characteristics, electric blowers mounted on electric vacuum cleaners are required to have high output, but are also required to be small and lightweight. The requirement for high output can be achieved, for example, by mounting a large-diameter impeller and rotating the motor at high speed. However, increasing the size of the impeller leads to an increase in size and weight of the electric blower and the electric vacuum cleaner. Furthermore, a motor that rotates a large-diameter impeller at high speed requires high reliability in terms of the durability of the impeller and bearings, so there is a practical limit to how fast the rotation speed can be increased.

[0003] The electric blower disclosed in the following Patent Document 1 includes multiple impellers. This allows high output without increasing the diameter of each impeller. In addition, the small diameter allows for high-speed rotation, achieving higher output.

[0004] This electric blower includes a motor section (motor) having a rotor shaft (shaft), an upstream impeller joined to one axial end of the rotor shaft so as to rotate integrally and draw in air from outside the machine, and a downstream impeller joined to the other axial end of the rotor shaft so as to rotate integrally and draw in air discharged by the upstream impeller. In addition, bearings that rotatably support the rotor shaft are provided on the downstream side of the upstream impeller and the upstream side of the downstream impeller, respectively.

[0005] In an electric blower configured in this way, air drawn in by the upstream impeller passes inside the motor, which is equipped with a rotor including a bearing, and is drawn into the downstream impeller. The output of an electric blower configured with multiple impellers in this way has the characteristic of having a higher static pressure and lower air volume than the output of multiple electric blowers equipped with only one impeller of the same shape, when they are operated with the same number of impellers and the same total axial force rotating the impellers. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2013-72290 A Summary of the Invention [Problem to be solved by the invention]

[0007] In vacuum cleaners, on the one hand, static pressure is important as a stronger suction force, and on the other hand, air volume is required as a force to suck in more dust. When a high air volume is required, the impeller is made larger in diameter or rotates at a higher speed, but the larger diameter impeller requires higher strength due to the increased centrifugal force caused by the larger diameter, and the high air volume achieved by high speed rotation cannot be achieved, so the electric blower required for a high air volume becomes larger.

[0008] The present disclosure has been made to solve the above-mentioned problems. An object of the present disclosure is to provide a small, lightweight electric blower that has a large air volume and high output, or to provide an electric vacuum cleaner equipped with such an electric blower. [Means for solving the problem]

[0009] The electric blower according to the present disclosure includes a motor, a first impeller, a second impeller, and an outer shell part. The motor includes a rotor having a shaft and a core attached to the shaft, a stator, and a motor housing that houses the core and the stator. The first impeller is attached to an end of the shaft on one axial side. The second impeller is attached to an end of the shaft on the other axial side. The outer shell part surrounds the motor, the first impeller, and the second impeller, and forms a first flow path and a second flow path therein. The first flow path and the second flow path are flow paths that discharge gas that has flowed in from the one axial side to the other axial side. The first flow path is formed to pass through a space in which the first impeller is housed. The second flow path is formed to pass through a space in which the second impeller is housed. The first flow path and the second flow path are not spatially continuous.

[0010] The electric vacuum cleaner according to the present disclosure is equipped with the electric blower described above. Effect of the Invention

[0011] According to the present disclosure, since the first impeller and the second impeller respectively operate in a first flow path and a second flow path that are not spatially continuous, it is possible to provide an electric blower that is small, lightweight, and has a high air volume and high output. [Brief description of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view passing through the central axis of a shaft of the electric blower according to embodiment 1. FIG. [Diagram 2] 2 is an enlarged view showing the details of part A shown in FIG. [Diagram 3] FIG. 2 is a projection view from direction B shown in FIG. [Figure 4] 2 is a cross-sectional view taken along line CC shown in FIG. [Diagram 5] FIG. 2 is a cross-sectional view taken along line DD shown in FIG. [Figure 6] 11 is a cross-sectional view passing through the central axis of the shaft of the electric blower according to embodiment 2, showing an enlarged view of the periphery of a second bearing. FIG. [Figure 7]13 is a cross-sectional view passing through the central axis of the shaft of the electric blower according to a modification of the second embodiment, showing an enlarged view of the periphery of a second bearing. FIG. [Figure 8] 11 is a cross-sectional view passing through the central axis of the shaft of the electric blower according to embodiment 3, showing an enlarged view of the periphery of a second bearing. FIG. [Figure 9] 9 is an enlarged view showing the periphery of a seal member provided in the downstream groove portion shown in FIG. 8. FIG. [Figure 10] FIG. 13 is a cross-sectional view passing through the central axis of the shaft of the electric blower according to a modification of the third embodiment, showing an enlarged view of the periphery of the second bearing when the motor is not operating. [Figure 11] FIG. 13 is a cross-sectional view taken along the central axis of the shaft of the electric blower according to a modification of the third embodiment, showing an enlarged view of the periphery of the seal member provided in the downstream groove portion when the motor is not operating. [Figure 12] FIG. 13 is a cross-sectional view passing through the central axis of the shaft of the electric blower according to a modification of the third embodiment, showing an enlarged view of the periphery of the second bearing when the motor is operating. [Figure 13] FIG. 13 is a cross-sectional view taken along the central axis of the shaft of the electric blower according to a modification of the third embodiment, illustrating an enlarged view of the periphery of the seal member provided in the downstream groove portion when the motor is operating. [Figure 14] FIG. 13 is a cross-sectional view taken along the central axis of the shaft of the electric blower according to a modification of the third embodiment, illustrating an enlarged view of the periphery of the seal member provided in the downstream groove portion when the motor is operating. [Figure 15] 13 is a cross-sectional view passing through the central axis of the shaft of the electric blower according to embodiment 4, showing an enlarged view of the periphery of a first bearing. FIG. [Figure 16] FIG. 13 is a cross-sectional view passing through the central axis of the shaft of the electric blower according to embodiment 5, showing an enlarged view of the periphery of a second bearing. [Figure 17] FIG. 13 is a cross-sectional view passing through the central axis of the shaft of the electric blower according to the sixth embodiment. [Figure 18] FIG. 13 is a cross-sectional view passing through the central axis of the shaft of the electric blower according to the seventh embodiment. [Figure 19] FIG. 13 is a partial cross-sectional side view of the vacuum cleaner according to the eighth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the embodiments will be described with reference to the drawings. The same reference numerals in each drawing indicate the same or corresponding parts. In this disclosure, overlapping descriptions will be appropriately simplified or omitted. This disclosure may include any combination of the configurations disclosed in each of the following embodiments. Furthermore, even if not specifically stated, the shapes, materials, manufacturing methods, etc. described in this disclosure may be appropriately selected as long as they do not contradict the gist of this disclosure.

[0014] Unless otherwise specified in this disclosure, with reference to Fig. 1, the axial direction includes the longitudinal direction of the shaft 1, which is elongated in one direction, and a direction parallel to this longitudinal direction. The radial direction is a direction perpendicular to the axial direction and passing through the center of the shaft 1. The circumferential direction is a circumferential direction of a circle concentric with the central axis Cl of the shaft 1. One axial side is the front side or upper side, and the other axial side is the rear side or lower side.

[0015] Embodiment 1 Fig. 1 is a cross-sectional view passing through the central axis of shaft 1 of electric blower 101 according to embodiment 1. Fig. 2 is an enlarged view showing details of part A shown in Fig. 1. Fig. 3 is a projection view from direction B shown in Fig. 1. Fig. 4 is a cross-sectional view taken along line CC shown in Fig. 1. Fig. 5 is a cross-sectional view taken along line DD shown in Fig. 1.

[0016] The electric blower 101 includes a motor 10, a first impeller 11, a second impeller 12, and an outer shell part 20.

[0017] The motor 10 is, for example, a brushless motor. The motor 10 rotates at, for example, a rated rotation speed of 100,000 [r / min]. Note that the motor 10 is not limited to a brushless type, and may be, for example, a brushed motor. The range of rotation speed that the motor 10 can achieve may be, for example, 30,000 to 130,000 [r / min]. The motor 10 includes a rotor 5, a stator 7, and a motor housing 8.

[0018] The rotor 5 includes a shaft 1 and a core 2. The shaft 1 includes a large diameter portion 1a at the approximate center in the axial direction, and a small diameter portion 1b and a small diameter portion 1c at both ends in the axial direction, sandwiching the large diameter portion 1a. The outer diameter of the large diameter portion 1a is larger than the outer diameters of the small diameter portions 1b and 1c. The core 2 is cylindrical and is attached to the outer periphery of the large diameter portion 1a of the shaft 1. The axial dimension of the core 2 is set smaller than the axial dimension of the large diameter portion 1a. The core 2 is made of a magnetic material, for example, a mixture of a permanent magnet made of neodymium or the like and a resin material, and is attached to the shaft 1 by adhesion or integral molding. For example, a two-liquid reactive type or anaerobic adhesive can be used as the adhesive for adhering the core 2.

[0019] The motor 10 includes a first bearing 3 and a second bearing 4. The first bearing 3 is, for example, a ball bearing including an inner ring 3a, an outer ring 3b, and a number of balls 3c. The inner ring 3a is press-fitted into the small diameter portion 1b of the shaft 1. There is a step at the boundary between the large diameter portion 1a and the small diameter portion 1b of the shaft 1, and the axial position of the bearing 3 is determined by the abutment of the end face on one axial side of the large diameter portion 1a with the inner ring 3a of the first bearing 3. The second bearing 4 has a similar configuration to the first bearing 3.

[0020] The stator 7 is formed by windings 6 wound around a stator core 7a made of laminated thin electromagnetic steel sheets. The ends of the windings 6 are electrically connected to terminals (not shown). The stator core 7a and the windings 6 are electrically insulated by an insulating member (not shown). The windings 6 and the terminals may be connected, for example, by soldering, fusing, or by bite-in terminals. When a current flows through the terminals, the stator 7 generates a magnetic flux, causing the rotor 5 to rotate.

[0021] The motor housing 8 surrounds the rotor 5 and the stator 7. The motor housing 8 is a housing having a cylindrical portion 8a arranged coaxially with the shaft 1, and an upper plate portion 8b and a lower plate portion 8c that are circular in plan view and close the end faces of both axial sides of the cylindrical portion 8a. At the center of the upper plate portion 8b and the lower plate portion 8c, holes through which the small diameter portions 1b and 1c of the shaft 1 penetrate are opened, respectively. In addition, a bearing housing 9 is provided at the center of each of the upper plate portion 8b and the lower plate portion 8c. The bearing housing 9 supports (holds) the first bearing 3 and the second bearing 4 of the rotor 5 so that they can rotate freely. The outer ring 4b of the first bearing 3 and the second bearing 4 is fixed to the inner surface 9a of the bearing housing 9 via an adhesive or the like. For example, a two-liquid reaction type or an anaerobic adhesive can be used as the adhesive. The end face of the outer ring 4b abuts against the bottom surface 9b of the bearing housing 9. Furthermore, the stator 7 is fixed by interference fitting to the inner circumferential surface of the motor housing 8. As an example of the interference fitting, a shrink fitting can be used in which the motor housing 8 is heated, the cylindrical portion 8a of the motor housing 8 is expanded by thermal expansion, the stator 7 is inserted, and then the motor housing 8 is cooled.

[0022] An upstream vent 31 is provided in the cylindrical portion 8a of the motor housing 8. The upstream vent 31 is provided as an opening (hereinafter also referred to as "opening") at a position on the cylindrical side surface of the motor housing 8 where the inner peripheral surface of the motor housing 8 and the stator core 7a of the stator 7 are not in contact with each other when the stator 7 is fixed to the motor housing 8. The upstream vent 31 is connected to an upstream flow passage 29 described later, and allows air to flow into the motor housing 8. The upstream vent 31 does not have to be a single opening, and multiple openings may be provided. The upstream vent 31 in the first embodiment is provided near the winding 6 of the stator 7 and on the first bearing 3 side.

[0023] Further, a downstream vent 32 is provided in the lower plate portion 8c. The downstream vent 32 is provided on the end face of the motor housing 8, opening toward the second bearing 4. The downstream vent 32 is connected to a space that accommodates the second impeller 12 described later, and allows air to flow out from inside the motor housing 8. The downstream vent 32 opens, for example, concentrically with the central axis of the shaft 1. A plurality of downstream vents may be provided, divided in the circumferential or radial direction. The motor housing 8 has a downstream groove 14 on the surface where the downstream vent 32 opens. The downstream groove 14 is an annular groove that opens to the outside of the motor housing 8 and is connected to the central axis of the shaft 1.

[0024] The cylindrical portion 8a, the upper plate portion 8b, and the lower plate portion 8c of the motor housing 8 may be formed integrally or separately. The motor housing 8 may be formed by appropriately dividing and molding the portions and combining them. It is desirable that the motor housing 8 is not spatially continuous with the outside except for the upstream vent 31 and the downstream vent 32. The material and manufacturing method of the motor housing 8 may be selected from aluminum die casting, cutting by cutting, resin molding, and the like.

[0025] The first impeller 11 includes a hub 11a that is high in the radial center and decreases in height as it spreads outward, a plurality of blades 11b provided on one axial surface (upper surface) of the hub 11a, and a center hole 11c opened in the center of the hub 11a. The small diameter portion 1b of the shaft 1 is inserted into and fitted into the center hole 11c. The small diameter portion 1b of the shaft 1 is attached by press-fitting or bonding into the center hole 11c. Alternatively, a threaded portion may be provided at the tip of the small diameter portion 1b of the shaft 1, and the first impeller 11 may be fixed by a nut. The first impeller 11 is positioned in the axial direction by being fixed between the first bearing 3 and the first impeller 11 via a cylindrical spacer 13.

[0026] The second impeller 12, like the first impeller 11, includes a hub 12a that is high in the radial center and decreases in height as it spreads outward toward the periphery, a plurality of blades 12b provided on one axial side surface (upper surface) of the hub 12a, and a center hole 12c opened in the center of the hub 12a. The small diameter portion 1c of the shaft 1 is inserted into and fitted into the center hole 12c. The small diameter portion 1b of the shaft 1 is attached to the center hole 11c by press-fitting or bonding. Alternatively, a screw portion may be provided at the tip of the small diameter portion 1c of the shaft 1, and the second impeller 12 may be fixed by a nut. The second impeller 12 is positioned in the axial direction by being fixed to the second bearing 4 via a cylindrical spacer 13 interposed therebetween.

[0027] The first impeller 11 and the second impeller 12 have a surface on one axial side on which a plurality of blades 11b, 12b are provided as the suction side. Hereinafter, this surface is also referred to as the suction side end surface. When the first impeller 11 and the second impeller 12 rotate, air flows in from the suction side and is discharged from the radial direction of the first impeller 11 and the second impeller 12.

[0028] The second impeller 12 further includes an annular front projection 12d centered on the central hole 12c on the suction side end surface of the hub 12a. The height of the front projection 12d is set so that at least a part (a tip portion) of the front projection 12d enters the inside of the downstream groove 14 of the motor housing 8 when the second impeller 12 is attached to the small diameter portion 1c of the shaft 1.

[0029] The first impeller 11 can be made to have the same shape as the second impeller 12. When the first impeller 11 is made to have the same shape as the second impeller 12, the first impeller 11 further has an annular front projection 11d centered on the central hole 11c on the suction side of the hub 11a, i.e., on the upper surface (front surface) which is the end surface on one side in the axial direction, and the front projection 11d has a front projection side surface portion 11e on the radially outer side. The front projection 11d does not impair the function of the first impeller 11. By making the first impeller 11 and the second impeller 12 have the same shape, parts can be shared and manufacturing costs can be reduced.

[0030] It is desirable that the first impeller 11 and the second impeller 12 are molded from a lightweight and high-strength material. The material of the first impeller 11 and the second impeller 12 may be, for example, carbon fiber reinforced plastic.

[0031] The outer part 20 is a housing that covers the motor 10, the first impeller 11, and the second impeller 12 from the outside. The outer part 20 is a housing that surrounds the motor 10, the first impeller 11, and the second impeller 12, and has a first flow path 41 and a second flow path 42, which will be described later, formed inside. The first flow path 41 and the second flow path 42 are flow paths that discharge gas that has flowed in from one axial side to the other axial side. In addition, the one axial side is the upstream side in the gas flow of the first flow path 41 and the second flow path 42, and the other axial side is the downstream side in the gas flow of the first flow path 41 and the second flow path 42. The first flow path 41 is formed to pass through the space S1 in which the first impeller 11 is housed, and the second flow path 42 is formed to pass through the space S3 in which the second impeller 12 is housed. The outer shell part 20 may be a single part, or may be composed of multiple parts.

[0032] The outer part 20 has a first intake port 21, which is generally circular in plan view and opens on the upper wall of the suction side of the first impeller 11, and a second intake port 22 that opens radially outward from the first intake port 21. It is preferable that a plurality of second intake ports 22 are provided and arranged point-symmetrically about the axis of the shaft 1. In this embodiment, for example, as shown in FIG. 3, four second intake ports 22 are opened at equal intervals in the circumferential direction along a virtual circle centered on the axis of the shaft 1. That is, a single first intake port 21 and a plurality of second intake ports 22 are opened on the upper wall of the outer part 20.

[0033] The outer part 20 has a cylindrical first side wall 25 on the radial outside of the first impeller 11. The first side wall 25 has a plurality of side vents 28. The plurality of side vents 28 are preferably arranged point-symmetrically about the axis of the shaft 1. In this embodiment, for example, as shown in FIG. 4, four side vents 28 are opened at equal intervals in the circumferential direction along a virtual circle (not shown) centered on the axis of the shaft 1. Each side vent 28 connects the outer flow passage 30 and the space S1 that houses the first impeller 11. That is, the outer flow passage 30 and the space S1 communicate with each other (are spatially continuous) through each side vent 28. The outer flow passage 30 is defined between an outer peripheral side wall 27 that covers the outermost periphery of the electric blower 101 and the outer periphery of the motor 10. The outer flow passage 30 extends in the axial direction of the shaft 1, and is connected to a first exhaust port 23 provided in a lower wall on the opposite side (the other axial side) to the first intake port 21 in the axial direction of the electric blower 101. The outer flow passage 30 may be divided into a plurality of portions in the cross section shown in Figs. 4 and 5.

[0034] The outer part 20 has an upstream flow passage 29 connected to the second intake port 22. The upstream flow passage 29 is defined radially outside the first impeller 11. The upstream flow passage 29 is not connected to the space S1 that houses the first impeller 11. A plurality of upstream flow passages 29 are defined between the outer peripheral side wall 27 and the first side wall 25, and each upstream flow passage 29 is connected to a plurality of second intake ports 22. As shown in FIG. 4 and FIG. 5, the upstream flow passage 29 is separated from a plurality of outer flow passages 30 by a partition wall 35. Therefore, the upstream flow passage 29 and the outer flow passage 30 are not spatially continuous. The upstream flow passage 29 is connected to an upstream vent 31 opened in the cylindrical portion 8a of the motor housing 8, and causes air to flow into the internal space S2 of the motor housing 8 that houses the rotor 5 and the stator 7 of the motor 10. Hereinafter, the internal space S2 of the motor housing 8 may also be referred to as the internal space S2 of the motor 10.

[0035] The outer part 20 has a cylindrical second side wall 26 on the radial outside of the second impeller 12. The second side wall 26 separates the outer flow passage 30 from a space S3 in which the second impeller 12 is housed. The space S3 communicates with the internal space S2 via a downstream vent port 32 provided in the lower plate portion 8c of the motor housing 8.

[0036] The outer shell part 20 has a rear surface portion 34 on the opposite suction side (lower side) of the second impeller 12. The rear surface portion 34 has a second exhaust port 24 connected to the space S3.

[0037] Thus, electric blower 101 has first intake port 21 and second intake port 22 on one axial side surface, and first exhaust port 23 and second exhaust port 24 on the other axial side surface.

[0038] Next, the air flow in the electric blower 101 will be described.

[0039] When the motor 10 operates and the rotor 7 rotates, the first impeller 11 and the second impeller 12 fixed to the shaft 1 rotate, respectively, to generate an air flow. The electric blower 101 draws in air from the first intake port 21 and the second intake port 22, and discharges the air from the first exhaust port 23 and the second exhaust port 24.

[0040] Here, the first intake port 21, the space S1 in which the first impeller 11 is housed, and the first exhaust port 23 form a continuous first flow path 41. The second intake port 22, the internal space S2, the space S3 in which the second impeller 12 is housed, and the second exhaust port 24 form a continuous second flow path 42. The first flow path 41 and the second flow path 42 are not spatially continuous inside the electric blower 101. Specifically, the first flow path 41 and the second flow path 42 are separated by the outer part 20 and the motor 10, and are not spatially continuous (communicating) and are isolated from each other. More specifically, a part of the first flow path 41 and the second flow path 42 is separated by one or both of the first bearing 3 and the second bearing 4 of the motor 10. In this embodiment, a case where a part of the first flow passage 41 and the second flow passage 42 (the space S1 and the space S2) is separated by the first bearing 3 is shown as an example.

[0041] As the first impeller 11 rotates, air from a first air intake port 21 provided on the suction side of the first impeller 11 flows into the electric blower 101. The air flows into the outer flow passage 30 from a side air vent 28 opened on the radially outer side of the space S1 that houses the first impeller 11. The air that flows into the outer flow passage 30 passes the radially outer side of the motor 10 and the radially outer side of the second impeller 12 without passing through spaces S2 and S3 described below, and is discharged to the outside of the electric blower 101 from a first exhaust port 23.

[0042] Furthermore, as the second impeller 12 rotates, air flows into the electric blower 101 through the multiple second intake ports 22. The air flows through the upstream flow passage 29 and into the internal space S2 of the motor 10 through the upstream ventilation port 31 that opens into the side surface of the motor housing 8. The upstream ventilation port 31 opens near the winding 6 wound around the stator 7a or the first bearing 3. Therefore, the air that has flowed into the internal space S2 of the motor 10 efficiently cools the winding 6 and the first bearing 3, passes through the internal flow passage 33 (see FIG. 5 ), and reaches the space S3 in which the second impeller 12 is housed through the downstream ventilation port 32, and is discharged to the outside of the electric blower 101 through the second exhaust port 24.

[0043] Here, the second bearing 4 includes an inner ring 4a, an outer ring 4b, and balls 4c, and the internal space of the second bearing 4 formed by the inner ring 4a and the outer ring 4b is filled with lubricating grease (not shown). When the second impeller 12 rotates and generates an airflow, a pressure difference occurs between the upstream and downstream sides of the second bearing 4, generating an airflow that passes through the inside of the second bearing 4, which may cause the lubricating grease to leak out of the second bearing 4. The leakage of the lubricating grease may cause a decrease in performance of the second bearing 4, the generation of abnormal noise, and the like.

[0044] Therefore, in the first embodiment, the lower surface of the bearing housing 9 provided in the motor housing 8, i.e., on the downstream side of the second bearing 4, is provided with a downstream groove 14 recessed upward, and the second impeller 12 is provided with a front protrusion 12d protruding upward on the upper surface (front surface) on one axial side. A part including the tip portion of the front protrusion 12d enters the downstream groove 14, thereby lengthening the flow path on the downstream side of the second bearing 4 and narrowing the gap, making it difficult for an airflow to pass through the inside of the second bearing 4. As a result, it is possible to suppress the lubricating grease from leaking out of the second bearing 4.

[0045] As described above, according to this embodiment, the first impeller 11 and the second impeller 12 act in the first flow passage 41 and the second flow passage 42, which are not spatially continuous (independent), respectively, and the first flow passage 41 and the second flow passage 42 suck air from the first air intake port 21 and the second air intake port 22, which are independent, respectively, so that it is not necessary to increase the diameter of the impeller. Therefore, it is possible to provide a small and lightweight electric blower with a large air volume and high output. In addition, the first air intake port 21 and the second air intake port 22 are arranged (opened) facing the same direction on a surface on one side of the axial direction of the outer part 20. Therefore, the electric vacuum cleaner (see FIG. 19) described later that is equipped with the electric blower 101 according to this embodiment does not need to form a complex flow passage, and can utilize the airflow generated by the first impeller 11 and the second impeller 12, and it is possible to provide a small and lightweight electric vacuum cleaner 100 with a large air volume and high output. Furthermore, since a portion of the front protrusion 12d penetrates into the downstream groove portion 14, the outflow of lubricating grease is suppressed, thereby making it possible to provide a highly reliable electric blower 101 and vacuum cleaner 100 in which the performance of the second bearing 4 is not degraded.

[0046] Embodiment 2 FIG. 6 is a cross-sectional view passing through the central axis of shaft 1 of electric blower 101 according to embodiment 2, showing an enlarged view of the periphery of second bearing 4. As shown in FIG.

[0047] As shown in FIG. 6, the front projection 12d of the second impeller 12 has a front projection side surface 12e that is substantially parallel to the central axis of the shaft 1 (extending in the axial direction). The downstream groove 14 recessed in the lower surface of the bearing housing 9 of the motor housing 8 has a downstream groove side surface 14a. The downstream groove side surface 14a is a cylindrical surface that is substantially parallel to the axial center of the shaft 1, similar to the front projection side surface 12e. A part of the front projection 12d, including its tip, is inserted into the downstream groove 14. In this state, the tip of the front projection 12d is separated from the bottom surface of the downstream groove 14 by a gap E, and the downstream groove side surface 14a faces the front projection side surface 12e by a gap G.

[0048] According to this embodiment, a part of the front projection 12d enters the inside of the downstream groove 14, so that the flow path on the downstream side of the second bearing 4 becomes longer and the gap E becomes narrower, so that airflow passing through the inside of the second bearing 4 is less likely to occur. As a result, the lubricating grease is prevented from leaking out of the second bearing 4. In addition, the front projection side portion 12e and the downstream groove side portion 14a are parallel to the central axis of the shaft 1 and face each other, so that the gap G can be maintained even when the rotor 5 including the shaft 1 moves in the axial direction, and the lubricating grease 4d can be prevented from leaking out of the second bearing 4.

[0049] Incidentally, in order for the rotor 5 to rotate stably without generating abnormal noise, it is effective to bias the outer ring 4b of the second bearing 4 in the axial direction.

[0050] Next, a modified example of the second embodiment will be described. FIG. 7 is a cross-sectional view passing through the central axis of the shaft 1 of the electric blower 101 according to the modified example of the second embodiment, and is an enlarged view of the periphery of the second bearing 4. In the modified example shown in FIG. 7, a preload member 15 is provided between the outer ring 4b and the bottom surface 9b of the bearing housing 9. As the preload member 15, an elastic member such as a wave washer can be used. By providing the preload member 15 in this manner, even when the rotor 5 moves to one axial side (the suction side) due to the negative pressure of the impeller, the preload member 15 makes the outer ring 4b follow (follow) the rotor 5, so that the rotor 5 can rotate stably without abnormal noise.

[0051] Here, the gap E between the tip of the front projection 12d and the bottom surface of the downstream groove 14 (upper surface in FIG. 7) changes with the axial movement of the rotor 5. In this case, if the front projection side surface 12e is not provided, and the assembly dimensions are set so that the tip of the front projection 12d does not come into contact with the bottom surface of the downstream groove 14, taking into consideration the mounting error in the manufacture of each part, the gap E needs to be large, and it is difficult to achieve the purpose of suppressing the outflow of the lubricating grease 4d of the second bearing 4. On the other hand, according to this modified example, the front projection side surface 12e and the downstream groove side surface 14a are opposed to each other with the gap G, so that the gap G does not change even when the rotor 5 moves in the axial direction due to the negative pressure of the impeller, etc., and therefore the minimum gap G can be set. As a result, the lubricating grease 4d can be suppressed from outflowing to the outside of the second bearing 4.

[0052] Embodiment 3 Fig. 8 is a cross-sectional view passing through the central axis of shaft 1 of electric blower 101 according to embodiment 3, and is an enlarged view of the periphery of second bearing 4. Fig. 9 is an enlarged view of the periphery of seal member 16 provided in downstream groove portion 14 shown in Fig. 8.

[0053] 8 and 9, the downstream groove portion 14 has a seal member 16 therein. The tip of the front protrusion 12d rotates in a state of contact (abutment) with the seal member 16. Alternatively, the tip of the front protrusion 12d rotates in a state of being inserted into the seal member 16.

[0054] The seal member 16 is preferably an elastic member having high sliding properties. Resin or the like can be used as the elastic member. The seal member 16 can be filled in the following manner. For example, liquid resin is filled in the downstream groove 14, and the resin is cured by irradiating ultraviolet light, so that the seal member 16 can be filled in a solid ultraviolet-curable resin having elasticity. Alternatively, the seal member 16 made of resin that has been molded separately in advance may be fixed to the downstream groove 14 with an adhesive or the like to fill the downstream groove 14. Alternatively, the seal member 16 filled in the entire downstream groove 14 may be rotated in contact with the front protrusion 12d, so that the contact portion is scraped off, and a part of the front protrusion 12d may be inserted into the seal member 16. A minute gap may be formed between the seal member 16 and the part of the front protrusion 12d that has entered the seal member 16 by scraping off the seal member 16. That is, a part of the front protrusion 12d and the seal member 16 may be in a non-contact state.

[0055] 9, it is preferable that the seal member 16 has a shape in which the axial height gradually changes from the downstream groove side surface 14a facing the front protrusion 12d in the radial direction. In particular, it is preferable that the portion corresponding to the gap G in the vicinity of the downstream groove side surface 14a is high (thick) and the portion farther from the downstream groove side surface 14a (the radially inner portion) is low (thin).

[0056] According to this embodiment, the second impeller 12 rotates with the tip of the front projection 12d in contact with the seal member 16, so that no air flow occurs in front of or behind the second bearing 4, and it is possible to more reliably prevent the lubricating grease from leaking out of the second bearing 4. Furthermore, the seal member 16 is filled thicker from the radial inside to the radial outside of the downstream groove 14 so that the portion corresponding to the gap G becomes larger, thereby enhancing the effect of suppressing the air flow.

[0057] Next, a modified example of the third embodiment will be described. FIG. 10 is a cross-sectional view passing through the central axis of the shaft 1 of the electric blower 101 according to the modified example of the third embodiment, and is an enlarged view of the periphery of the second bearing 4 when the motor 10 is not operating. FIG. 11 is a cross-sectional view passing through the central axis of the shaft 1 of the electric blower 101 according to the modified example of the third embodiment, and is an enlarged view of the periphery of the seal member 16 provided in the downstream groove portion 14 when the motor 10 is not operating. FIG. 12 is a cross-sectional view passing through the central axis of the shaft 1 of the electric blower 101 according to the modified example of the third embodiment, and is an enlarged view of the periphery of the second bearing 4 when the motor 10 is operating. FIG. 13 and FIG. 14 are cross-sectional views passing through the central axis of the shaft 1 of the electric blower 101 according to the modified example of the third embodiment, and are an enlarged view of the periphery of the seal member 16 provided in the downstream groove portion 14 when the motor 10 is operating.

[0058] As shown in Figures 10 and 11, when the motor 10 is not operating, the seal member 16 and the front projection 12d of the second impeller 12 are separated and do not come into contact with each other. On the other hand, as shown in Figures 12 and 13, when the motor 10 is operating, the rotor 5 moves to the suction side (one axial side) due to the negative pressure of the impeller, and the front projection 12d enters the seal member 16.

[0059] In the above embodiment 3, the front protrusion 12d of the impeller 12 is in contact with the sealing member 16. Therefore, particularly when the tip of the front protrusion 12d penetrates deeply into the sealing member 16, the torque required to rotate the impeller 12 becomes large, and there is a risk that excessive current will flow through the motor 10.

[0060] In contrast, in this modification, when motor 10 of electric blower 101 is not operating (i.e., before it is started), front projection 12d is not in contact with seal member 16, so the torque required for motor 10 to start rotating second impeller 12 does not increase. Furthermore, as the rotation speed of motor 10 increases, the negative pressure of the impeller increases and rotor 5 moves axially toward the suction side, so that front projection 12d reaches seal member 16 and gradually scrapes away seal member 16, reaching the state shown in Fig. 13. When front projection 12d reaches seal member 16, the rotation speed of motor 10 is sufficiently high and only a small amount of seal member 16 is scraped away, so the required torque is small.

[0061] In this way, the front projection 12d enters the seal member 16 at the first start, and as shown in FIG. 14, the seal removal portion 16a is formed in the seal member 16. When the motor 10 is then started again from a stopped state, the front projection 12d enters the already formed seal removal portion 16a, and the front projection side portion 12e and the side surface 16b of the seal removal portion 16a move while contacting and sliding. The seal removal portion 16a may be formed by the front projection 12d not only by the operation of the motor 10 but also by an external force. For example, during the assembly process of the electric blower 101, the position of the rotor 5 may be moved by an external force to a position where the rotor 5 reaches when the electric blower 101 is operated, and in a state where the front projection 12d enters the seal member 16, the tip of the shaft 1 may be chucked with another rotating tool to forcibly rotate the shaft 1 to form the seal removal portion 16a. By forming seal removal portion 16a in advance in this manner, even a slight initial load is not generated on motor 10 of electric blower 101.

[0062] Furthermore, as in the above embodiment 3, the front protrusion 12d rotates in contact with the sealing member 16, so that no air flow is generated in front of or behind the second bearing 4, and the lubricating grease is prevented from leaking out of the second bearing 4.

[0063] According to this modification, when the motor 10 is not operating, the seal member 16 and the front projection 12d are spaced apart and not in contact with each other, so that it is possible to prevent the torque required for starting the motor 10 from becoming too large.

[0064] Embodiment 4 FIG. 15 is a cross-sectional view passing through the central axis of shaft 1 of electric blower 101 according to embodiment 4, showing an enlarged view of the periphery of first bearing 3. As shown in FIG.

[0065] As shown in FIG. 15, the first impeller 11 has an annular rear projection 11f on the opposite suction side of the hub 11a, that is, on the rear surface, which is the lower surface on the other axial side, that protrudes downward around the axial center of the central hole 11c. The rear projection 11f has a rear projection side surface 11g that is approximately parallel to the axial center of the shaft 1. The frame housing 8 (or the bearing housing 9) has an upstream groove 17 that is recessed downward on the upstream side of the first bearing 3, and the upstream groove 17 has an upstream groove side surface 17a on the radially outer side. A part of the rear projection 11f enters the upstream groove 17. The upstream groove side surface 17a faces the rear projection side surface 11g at a distance. The upstream groove 17 has a seal member 16 inside the groove, similar to the downstream groove 14. The tip of the rear projection 11f rotates in a state of contact (abutment) with the seal member 16. Alternatively, the rear surface protrusion 11f rotates with the tip end thereof inserted into the seal member 16. By scraping off the seal member 16, a minute gap may be formed between the seal member 16 and a part of the rear surface protrusion 11f that has entered the inside of the seal member 16. In other words, the part of the rear surface protrusion 11f and the seal member 16 may be in a non-contact state.

[0066] Here, the first bearing 3 includes an inner ring 3a, an outer ring 3b, and balls 3c, and the internal space of the first bearing 3 formed by the inner ring 3a and the outer ring 3b is filled with lubricating grease (not shown). When the first impeller 11 rotates and generates an airflow, a pressure difference occurs between the upstream and downstream sides of the first bearing 3, and there is a risk that the airflow passing through the inside of the first bearing 3 will cause the lubricating grease to flow out of the first bearing 3.

[0067] According to this embodiment, the first impeller 11 rotates with the rear surface protrusion 11f abutting or inserted into the sealing member 16 provided in the upstream groove portion 17 of the motor housing 8, thereby preventing air flow from occurring in front of or behind the first bearing 3 and preventing the lubricating grease from leaking out of the first bearing 3.

[0068] Embodiment 5. FIG. 16 is a cross-sectional view passing through the central axis of shaft 1 of electric blower 101 according to embodiment 5, showing an enlarged view of the periphery of second bearing 4.

[0069] 16, the second impeller 12 has an annular first front projection 51 that projects upward about the axial center of the central hole 12c on the suction side of the hub 12a, i.e., on the upper surface (front surface) that is the end surface on one axial side, and further has an annular second front projection 52 that has the same axial center as the first front projection 51, radially inward and closer to the axial center of the shaft 1 than the first front projection 51. In other words, the front surface of the second impeller 12 is provided with a plurality of (two in this embodiment) front projections 51, 52 in the radial direction. Further, the motor housing 8 (or the bearing housing 9) has a first annular downstream groove 61 recessed upward about the axial center of the shaft 1 on the second impeller 12 side, i.e., on the lower surface (rear surface) which is the end surface on the other axial side, and further has a second annular downstream groove 62 having the same axial center as the first downstream groove 61, radially inward and closer to the axial center of the shaft 1 than the first downstream groove 61. That is, the rear surface of the motor housing 8 or the bearing housing 9 is provided with a plurality of downstream grooves 61, 62 (two in this embodiment) in the radial direction.

[0070] The tips of the first front projection 51 and the second front projection 52 are inserted into the first downstream groove 61 and the second downstream groove 62, respectively. The first downstream groove 61 or the second downstream groove 62 includes a seal member 16 that is filled inside the groove. The tips of the first front projection 51 and the second front projection 52 rotate in a state of contact with the seal member 16. Alternatively, the tip of the front projection 12d rotates in a state of being inserted into the seal member 16.

[0071] According to this embodiment, the two front projections 51, 52 are provided concentrically, and the two downstream grooves 61, 62 are provided concentrically, and the second impeller 12 is rotated in a state where the two front projections 51, 52 are in contact with the seal members 16 filled in the downstream grooves 61, 62. This can further enhance the effect of preventing air flow in front of and behind the second bearing 4 and suppressing the outflow of the lubricating grease to the outside of the second bearing 4. Note that, in this embodiment, a case where a plurality of front projections 51, 52 and a plurality of downstream grooves 61, 62 are provided at intervals in the radial direction has been described as an example, but a plurality of rear projections 11f and a plurality of upstream grooves 17 can also be provided at intervals in the radial direction.

[0072] Embodiment 6 FIG. 17 is a cross-sectional view passing through the central axis of shaft 1 of electric blower 101 according to embodiment 6.

[0073] As shown in FIG. 17, the first intake port 21, the space S1 in which the first impeller 11 is present, the outer flow passage 30, and the first exhaust port 23 form a spatially continuous first flow passage 41. The second intake port 22, the upstream flow passage 29, the space S3 in which the second impeller 12 is present, the space S4 in which the control board 102 described later is present, the second exhaust port 24, and the side exhaust port 71 form a spatially continuous second flow passage 42. The first flow passage 41 and the second flow passage 42 are not spatially continuous but are independent. In this embodiment, the electric blower 101 further includes a control board 102 that controls the motor 10 on the downstream side of the second exhaust port 24. As the control board 102, a known one on which elements 102a such as a CPU and a memory are mounted is used, and detailed description thereof will be omitted here.

[0074] Next, the air flow in the electric blower 101 will be described.

[0075] As in the first embodiment, when the motor 10 operates, the rotor 7 rotates, and the first impeller 11 rotates, causing air to flow from the first intake port 21 into the space S1 inside the electric blower 101. The air that has flowed into the space S1 flows from the side vent 28 provided on the radially outer side of the first impeller 11 to the outer flow passage 30. The air that has flowed into the outer flow passage 30 passes the radially outer side of the motor 10 and the radially outer side of the second impeller 12 without passing through the spaces S2, S3, and S4, and is discharged from the first exhaust port 23 to the outside of the electric blower 101.

[0076] Furthermore, as the second impeller 12 rotates, air flows into the electric blower 101 from the second intake port 22. The air flows through the upstream flow passage 29 and into the internal space S2 of the motor 10 from the upstream vent port 31 opened on the side of the motor housing 8. The air that flows into the internal space S2 of the motor 10 passes through the internal flow passage 33 and reaches the space S3 in which the second impeller 12 is housed from the downstream vent port 32 while cooling the winding 6 and the first bearing 3, and flows into the space S4 in which the control board 102 is housed from the second exhaust port 24. The air that flows into the space S4 flows over the surface of the control board 102 to cool the elements 102a and the like provided on the control board 102, and is discharged to the outside of the electric blower 101 from the side exhaust port 71 opened on the radially outer side of the control board 201.

[0077] Exposure of the internal parts of motor 10, such as first bearing 3 or second bearing 4, and control board 102 to air containing moisture and dust can cause malfunctions due to corrosion or electrical shorts, so the air used to cool internal parts of motor 10, such as first bearing 3 or second bearing 4, and control board 102 needs to be clean. Meanwhile, there is a demand for electric vacuum cleaner 100 (see FIG. 19) equipped with electric blower 101 to suck in air containing moisture and dust.

[0078] According to this embodiment, the first flow path 41 and the second flow path 42 are isolated from each other and are not spatially continuous, so that these flow paths 41, 42 can selectively suck in different air. For example, it is possible that the air sucked in by the first air intake 21 constituting the first flow path 41 is air containing moisture and dust sucked in by the vacuum cleaner 100 from the floor surface, and the air sucked in by the second air intake 22 constituting the second flow path 42 is clean air with less moisture and dust sucked in from the outside air other than the floor surface. By configuring the vacuum cleaner 100 to allow such air flow, it is possible to provide a vacuum cleaner 100 that can suck in air containing moisture and dust while cooling the internal components of the motor 10 and the control board 102 with clean air.

[0079] Embodiment 7 FIG. 18 is a cross-sectional view passing through the central axis of shaft 1 of electric blower 101 according to the seventh embodiment.

[0080] As shown in FIG. 18, the first air intake 21, the space S1 in which the first impeller 11 is present, the outer flow passage 30, the first exhaust port 23, and the substrate rear exhaust port 72 form a first flow passage 41 that is spatially continuous. The second air intake 22, the upstream flow passage 29, the space S3 in which the second impeller 12 is present, and the side exhaust port 71 as the second exhaust port form a second flow passage 42 that is spatially continuous. The first flow passage 41 and the second flow passage 42 are not spatially continuous but independent. In this embodiment, the electric blower 101 includes a control board 102 that controls the motor 10 downstream of the first exhaust port 23. The control board 102 may be the same as that in the sixth embodiment.

[0081] Next, the air flow in the electric blower 101 will be described.

[0082] As in the first embodiment, the motor 10 operates to rotate the rotor 7, and the first impeller 11 rotates, causing air to flow from the first intake port 21 into the space S1 inside the electric blower 101. The air that flows into the space S1 flows from the side vent 28 provided on the radially outer side of the first impeller 11 to the outer flow passage 30. The air that flows into the outer flow passage 30 passes through the radially outer side of the motor 10 and the radially outer side of the second impeller 12 without passing through the spaces S2 and S3, and flows from the first exhaust port 23 into the space S4 that houses the control board 102. The air that flows into the space S4 flows over the surface of the control board 102 to cool the elements 102a and the like provided on the control board 102, and is discharged to the outside of the electric blower 101 from the board rear exhaust port 72 near the edge of the control board 102.

[0083] Furthermore, as the second impeller 12 rotates, air flows into the interior of the electric blower 101 through the second air intake port 22. The air flows through the upstream flow passage 29 and into the internal space S2 of the motor 10 through the upstream air vent 31 that opens into the side surface of the motor housing 8. The air that has flowed into the internal space S2 of the motor 10 cools the winding 6 and the first bearing 3, passes through the internal flow passage 33, and reaches the space S3 in which the second impeller 12 is housed through the downstream air vent 32, and is discharged to the outside of the electric blower 101 through the side exhaust port 71.

[0084] In this embodiment, the air flowing through first flow path 41 does not pass through heat generating parts such as windings 6 provided inside motor 10, and therefore the temperature is unlikely to rise from the outside air temperature (low temperature). In addition, since first flow path 41 and second flow path 42 are isolated from each other, the air flowing through first flow path 41 does not mix with the air flowing through second flow path 42 that has cooled heat generating parts such as windings 6 inside motor 10. As a result, the air flowing through first flow path 41 reaches the surface of control board 102 in a low temperature state, and therefore the cooling efficiency of control board 102 can be improved compared to the sixth embodiment.

[0085] Embodiment 8 FIG. 19 is a partial cross-sectional side view of the vacuum cleaner 100 according to the eighth embodiment.

[0086] The electric vacuum cleaner 100 is, for example, a cyclone type electric vacuum cleaner. The electric vacuum cleaner 100 includes a main body 110, a dust collecting section 120, an extension tube 130, and a suction tool 140.

[0087] Main body 110 houses electric blower 101 described in any one of the above embodiments 1 to 7. Electric blower 101 generates an air current that causes vacuum cleaner 100 to suck in air containing dust. First air intake 21 and second air intake 22 of electric blower 101 are arranged to be able to communicate with dust collection section 120 described later.

[0088] The main body 110 includes a handle 111 for handling the vacuum cleaner 100. The main body 110 also includes an operating section 112 on which a switch (not shown) for starting the electric blower 101 when the vacuum cleaner 100 is used is disposed. The extension tube 130 is for connecting the main body 110 and the suction tool 140 in a manner that allows air to pass through them, and is connected to the main body pipe section 113 of the main body 110. The suction tool 140 is connected to the end of the extension tube 130 opposite to the end connected to the main body pipe section 113. The main body 110 and the suction tool 140 can also be connected without the extension tube 130. The suction tool 140 sucks in air containing dust from a surface to be cleaned, such as a floor. The suction tool 140 includes an opening 141 on a surface facing the surface to be cleaned, such as a floor.

[0089] Dust collection unit 120 has a dust collection chamber 121. Dust collection chamber 121 is for storing dust. Dust collection unit 120 includes a separation unit 122. Separation unit 122 is for swirling air containing dust to separate the dust. The separated dust is stored in dust collection chamber 121. Main body 110 houses a secondary battery 150 that supplies power to drive electric blower 101. Vacuum cleaner 100 is a cordless vacuum cleaner in which electric blower 101 is driven by secondary battery 150.

[0090] In operation of the electric vacuum cleaner 100, when a switch (not shown) for driving the electric blower 101 of the operation unit 112 is turned ON, power is supplied to the electric blower 101 from the secondary battery 150. When the electric blower 101 starts up with power supplied thereto, the electric vacuum cleaner 100 starts sucking in dust-containing air from the opening of the suction tool 140 by the airflow generated by the electric blower 101.

[0091] The air containing dust sucked from the opening of the suction tool 140 passes through an air passage (not shown) of the extension tube 130, passes through the main body pipe section 113 of the main body 110, and is sent to the swirling section 123 of the dust collection section 120. The air containing dust is swirled and centrifuged in the swirling section 123, and the dust and air are separated in the separation section 122. The separated dust is stored in the dust collection chamber 121, and the separated air is sucked into the electric blower 101 from the first intake port 21 and the second intake port 22 of the electric blower 1, and is discharged outside the electric blower 101 from the first exhaust port 23 and the second exhaust port 24 of the electric blower 101. The air discharged from the electric blower 101 is discharged outside the main body 110 from the main body exhaust port 114 provided in the main body 100. In this manner, the electric blower 101 is driven to generate suction air to suck in air containing dust, and the dust is separated and collected in the dust collection chamber 121, thereby performing cleaning.

[0092] According to this embodiment, by including the electric blower 101, it is possible to provide a small, lightweight, high-volume, high-output vacuum cleaner 100. In addition, since a part of the front projection 12d enters the inside of the downstream groove 14, the outflow of the lubricating grease is suppressed, and therefore it is possible to provide a highly reliable vacuum cleaner 100 in which the performance of the second bearing 4 is not deteriorated.

[0093] Although the hot water supply system of the present disclosure has been described above by taking the embodiments as examples, as mentioned above, the present disclosure is not limited to the above-described embodiments.

[0094] In addition, among the features of the above-described embodiment, two or more features that can be combined may be combined. Various aspects of the present disclosure will be described below as supplementary notes. (Appendix 1) a motor including a rotor having a shaft and a core attached to the shaft, a stator, and a motor housing that accommodates the core and the stator; A first impeller attached to one axial end of the shaft of the rotor; a second impeller attached to the other axial end of the shaft of the rotor; an outer shell part that surrounds the motor, the first impeller, and the second impeller and defines a first flow path and a second flow path therein; Equipped with The first flow path is formed to pass through a space in which the first impeller is accommodated, The second flow path is formed to pass through a space in which the second impeller is accommodated, The first flow path and the second flow path are not spatially continuous. An electric blower characterized by: (Appendix 2) the motor includes a first bearing attached to the shaft and positioned on one axial side of the shaft relative to the core, and a second bearing attached to the shaft and positioned on the other axial side of the shaft relative to the core, 2. The electric blower according to claim 1, wherein a portion of the first flow path and a portion of the second flow path are separated by one or both of the first bearing and the second bearing. (Appendix 3) The outer shell part is a first intake port that opens on one axial side of the first impeller and through which gas flows in; a second intake port that opens radially outward of the first intake port and into which gas flows; a first exhaust port and a second exhaust port that open on an axially opposite side of the shaft from the first intake port and the second intake port and through which gas is discharged; Equipped with The first flow path is formed such that the first intake port, a space in which the first impeller is accommodated, and the first exhaust port are spatially continuous with each other, The electric blower according to claim 1 or 2, wherein the second flow path is formed so that the second intake port, an internal space of the motor housing, a space in which the second impeller is accommodated, and the second exhaust port are spatially continuous. (Appendix 4) The outer shell part is a first side wall covering an outer periphery of the first impeller; an outer circumferential side wall located radially outward of the first side wall and surrounding the motor; A side vent opening in the first side wall; an upstream flow passage formed between the first side wall and the outer circumferential side wall; an outer flow passage formed between an outer periphery of the motor and the outer periphery sidewall; Further equipped with The motor housing includes: an upstream vent opening on the first impeller side; a downstream vent opening on the second impeller side; Equipped with The first flow passage is formed such that the first intake port, a space in which the first impeller is accommodated, the side vent port, the outer flow passage, and the first exhaust port are spatially continuous with each other, The electric blower according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the second flow path is formed so that the second intake port, the upstream vent port, an internal space of the motor housing, the downstream vent port, a space in which the second impeller is accommodated, and a second exhaust port are spatially continuous. (Appendix 5) The second impeller has an annular front projection on one end surface in the axial direction, the motor housing includes an annular downstream groove corresponding to the front projection; The electric blower according to any one of claims 1 to 4, wherein the second impeller rotates with at least a portion of the front protrusion inserted into the downstream groove. (Appendix 6) The front projection includes a front projection side portion extending in an axial direction, The electric blower according to claim 5, wherein the downstream groove portion includes a downstream groove side portion facing the front protrusion side portion. (Appendix 7) the downstream groove portion includes a seal member therein, The electric blower according to claim 5 or 6, wherein the second impeller rotates with the front protrusion inserted into the downstream groove and in contact with the seal member. (Appendix 8) the downstream groove portion includes a seal member therein, The electric blower according to claim 5 or 6, wherein the second impeller rotates with at least a portion of the front protrusion inserted into the sealing member. (Appendix 9) The electric blower according to any one of claims 5 to 8, wherein the front protrusion and the downstream groove are provided in a radial direction in a plurality of positions. (Appendix 10) The electric blower according to any one of claims 7 to 9, wherein the front protrusion is not in contact with the sealing member inside the downstream groove when the second impeller is not rotating. (Appendix 11) the first impeller has an annular rear surface protrusion on the other axial end surface, the motor housing includes an annular upstream groove corresponding to the rear surface protrusion; 2. The electric blower according to claim 1, wherein the first impeller rotates with at least a portion of the rear surface protrusion inserted into the upstream groove portion. (Appendix 12) The rear projection includes a rear projection side portion extending in an axial direction, 12. The electric blower according to claim 11, wherein the upstream groove portion includes an upstream groove side portion facing the rear protrusion side portion. (Appendix 13) the upstream groove portion includes a seal member therein, 13. The electric blower according to claim 11, wherein the first impeller rotates with the rear surface protrusion inserted into the upstream groove and in contact with the seal member. (Appendix 14) the upstream groove portion includes a seal member therein, The electric blower according to any one of claims 11 to 13, wherein the first impeller rotates with at least a portion of the rear surface protrusion inserted into the sealing member. (Appendix 15) The electric blower according to any one of claims 11 to 14, wherein the rear surface protrusion and the upstream groove are provided in a radial direction in a plurality of positions. (Appendix 16) The electric blower according to any one of claims 7 to 10 and 13 to 15, wherein the sealing member is an ultraviolet-curable resin that is cured by exposure to ultraviolet light. (Appendix 17) The electric blower according to any one of claims 1 to 16, wherein the first impeller and the second impeller have the same shape. (Appendix 18) The electric blower according to any one of Supplementary Note 3 to Supplementary Note 17, characterized in that a control board is provided downstream of the second exhaust port, and a space in which the control board is present is not spatially continuous with the first flow path. (Appendix 19) The electric blower according to any one of Supplementary Note 3 to Supplementary Note 17, characterized in that a control board is provided downstream of the first exhaust port, and a space in which the control board is present is not spatially continuous with the second flow path. (Appendix 20) An electric vacuum cleaner equipped with the electric blower according to any one of Supplementary Note 1 to Supplementary Note 19. [Explanation of symbols]

[0095] 1...shaft, 1a...large diameter portion, 1b...small diameter portion, 1c...small diameter portion, 2...core, 3...first bearing, 3a...inner ring, 3b...outer ring, 3c...ball, 4...second bearing, 4a...inner ring, 4b...outer ring, 4c...ball, 5...rotor, 6...winding, 7...stator, 8...motor housing, 9...bearing housing, 9a...bearing housing side, 9b...bearing housing bottom, 10...motor, 11...first impeller, 11a...hub, 11b...blade, 11c...center hole, 11d...front protrusion, 11e...front projection side portion, 11f...rear projection portion, 11g...rear projection side portion, 12...second impeller, 12a...hub, 12b...blade, 12c...center hole, 12d...front projection portion, 12e...front projection side portion, 13...spacer, 14...downstream groove portion, 14a...downstream groove side portion, 15...preload member, 16...seal member, 16a...seal removal portion, 16b...side of seal removal portion 16a, 17...upstream groove portion, 17a...upstream groove side portion, 18...spacer, 20...outer shell part, 21...first Intake port, 22...second intake port, 23...first exhaust port, 24...second exhaust port, 25...first side wall, 26...second side wall, 27...outer peripheral side wall, 28...side vent, 29...upstream flow path, 30...outer flow path, 31...upstream vent, 32...downstream vent, 33...inner flow path, 34...rear surface, 35...partition wall, 41...first flow path, 42...second flow path, 51...first front projection, 52...second front projection, 61...first downstream groove, 62...second downstream groove, 71...side exhaust port, 100...electrical Vacuum cleaner, 101... electric blower, 110... main body, 111... handle, 112... operation section, 113... main body pipe section, 114... main body exhaust port, 120... dust collection section, 121... dust collection chamber, 122... separation section, 123... swivel section, 130... extension tube, 140... suction tool, 141... opening, 150... secondary battery, 201... control board, 202... element, S1... space in which first impeller 11 is housed, S2... internal space of motor housing 8, internal space of motor 10, S3... space in which second impeller 12 is housed

Claims

1. a motor including a rotor having a shaft and a core attached to the shaft, a stator, and a motor housing that accommodates the core and the stator; a first impeller attached to one axial end of the shaft of the rotor; a second impeller attached to an end portion of the rotor shaft on the other axial side; an outer shell part that surrounds the motor, the first impeller, and the second impeller and defines a first flow path and a second flow path therein; Equipped with the first flow path and the second flow path are flow paths that discharge gas that has flowed in from one axial side to the other axial side, The first flow path is formed to pass through a space in which the first impeller is accommodated, The second flow path is formed to pass through a space in which the second impeller is accommodated, The first flow path and the second flow path are not spatially continuous. An electric blower characterized by:

2. the motor includes a first bearing attached to the shaft and positioned on one axial side of the shaft relative to the core, and a second bearing attached to the shaft and positioned on the other axial side of the shaft relative to the core, 2. The electric blower according to claim 1, wherein a portion of the first flow path and a portion of the second flow path are separated by one or both of the first bearing and the second bearing.

3. The outer shell part is a first intake port that opens on one axial side of the first impeller and through which gas flows in; a second intake port that opens radially outward of the first intake port and into which gas flows; a first exhaust port and a second exhaust port that open on an axially opposite side of the shaft from the first intake port and the second intake port and through which gas is discharged; Equipped with The first flow path is formed such that the first intake port, a space in which the first impeller is accommodated, and the first exhaust port are spatially continuous with each other, 2. The electric blower according to claim 1, wherein the second flow passage is formed such that the second intake port, an internal space of the motor housing, a space in which the second impeller is accommodated, and the second exhaust port are spatially continuous with each other.

4. The outer shell part is a first side wall covering an outer periphery of the first impeller; an outer circumferential side wall located radially outward of the first side wall and surrounding the motor; a side vent opening in the first side wall; an upstream flow passage formed between the first side wall and the outer circumferential side wall; an outer flow passage formed between an outer periphery of the motor and the outer periphery sidewall; Further equipped with The motor housing includes: An upstream vent opening on the first impeller side; A downstream vent opening on the second impeller side; Equipped with The first flow passage is formed such that the first intake port, a space in which the first impeller is accommodated, the side vent port, the outer flow passage, and the first exhaust port are spatially continuous with each other, 2. The electric blower according to claim 1, wherein the second flow passage is formed such that the second intake port, the upstream vent port, an internal space of the motor housing, the downstream vent port, a space in which the second impeller is accommodated, and a second exhaust port are spatially continuous with each other.

5. the second impeller is provided with an annular front projection on one end surface in the axial direction, the motor housing includes an annular downstream groove corresponding to the front projection; The electric blower according to claim 1 , wherein the second impeller rotates with at least a portion of the front projection inserted in the downstream groove.

6. The front projection includes a front projection side portion extending in an axial direction, 6. The electric blower according to claim 5, wherein the downstream groove portion includes a downstream groove side portion facing the front projection side portion.

7. the downstream groove portion includes a seal member therein, 6. The electric blower according to claim 5, wherein the second impeller rotates with the front projection inserted in the downstream groove and in contact with the seal member.

8. the downstream groove portion includes a seal member therein, The electric blower according to claim 5 , wherein the second impeller rotates with at least a portion of the front projection inserted into the seal member.

9. The electric blower according to claim 5 , wherein a plurality of the front projections and the downstream grooves are provided in a radial direction.

10. 8. The electric blower according to claim 7, wherein the front projection is not in contact with the seal member inside the downstream groove when the second impeller is not rotating.

11. the first impeller is provided with an annular rear surface protrusion on the other axial end surface, the motor housing includes an annular upstream groove corresponding to the rear surface protrusion; The electric blower according to claim 1 , wherein the first impeller rotates with at least a portion of the rear surface protrusion inserted in the upstream groove portion.

12. The rear projection includes a rear projection side portion extending in an axial direction, The electric blower according to claim 11, wherein the upstream groove portion includes an upstream groove side portion facing the rear projection side portion.

13. the upstream groove portion includes a seal member therein, 12. The electric blower according to claim 11, wherein the first impeller rotates with the rear surface projection inserted in the upstream groove and in contact with the seal member.

14. the upstream groove portion includes a seal member therein, The electric blower according to claim 11, wherein the first impeller rotates with at least a portion of the rear surface protrusion inserted into the seal member.

15. The electric blower according to claim 11, wherein a plurality of the rear surface projections and the upstream grooves are provided in a radial direction.

16. 8. The electric blower according to claim 7, wherein the sealing member is made of an ultraviolet-curable resin that is cured by exposure to ultraviolet light.

17. 2. The electric blower according to claim 1, wherein the first impeller and the second impeller have the same shape.

18. 4. The electric blower according to claim 3, further comprising a control board disposed downstream of the second exhaust port, the control board being disposed in a space that is not spatially continuous with the first flow path.

19. 4. The electric blower according to claim 3, further comprising a control board disposed downstream of the first exhaust port, the control board being disposed in a space that is not spatially continuous with the second flow path.

20. A vacuum cleaner equipped with the electric blower according to any one of claims 1 to 19.

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