WO2022209344A1 - Electric air blower and cooling fan - Google Patents

Abstract

This electric air blower comprises: a rotor having a rotational shaft and a rotor core; a motor case that accommodates the rotor; a centrifugal fan that is attached to the rotational shaft and that is an example of a rotational fan that draws in external air; and a cooling fan that is attached to the rotational shaft, and that is for cooling the internal space of the motor case. The electric air blower includes: a first flow path through which passes an air flow generated by the rotation of the centrifugal fan; and a second flow path through which passes an air flow generated by the rotation of the cooling fan. The cooling fan is positioned between the centrifugal fan and the rotor core, and the cooling fan has a plurality of first fan blades provided on the rotor core side, and a plurality of second fan blades provided on the side opposite to the rotor core side.

Description

electric blower and cooling fan

The present disclosure relates to electric blowers and cooling fans. In particular, the present disclosure relates to cooling fans built into bypass type blower motors.

Electric blowers with motors are used in various electric appliances such as vacuum cleaners. An electric blower has a rotary fan, such as a centrifugal fan, attached to a rotary shaft of the motor in order to draw in outside air. A bypass type blower motor is known as one of the electric blowers (see Patent Document 1, for example). A bypass type blower motor is provided with a cooling fan for cooling the internal parts of the motor, in addition to a centrifugal fan for compressing and sucking outside air.

Conventionally, cooling fans used in bypass-type blower motors have a single-sided wing specification in which the fan blades are provided only on one side on the motor side. As this type of cooling fan, a single-sided blade radial fan is generally used.

However, when the cooling fan, which is a single-sided radial fan, rotates at high speed together with the centrifugal fan, the fan blades may deform due to the stress generated in the fan blades of the cooling fan. In this case, even the base plate that holds the fan blades may be deformed, causing the cooling fan to come into contact with the bracket or the like, causing a problem.

In addition, single-sided cooling fans have fan blades only on one side, so the fan blades need to be raised in order to increase the cooling airflow. However, if the fan blades of the cooling fan are raised, not only are the fan blades more likely to deform, but noise due to the rotation of the cooling fan also increases.

Japanese Patent Application Laid-Open No. 2003-284657

This disclosure was made to solve such problems. An object of the present disclosure is to provide an electric blower and a cooling fan that can suppress deformation of the cooling fan and suppress an increase in noise.

In order to achieve the above object, one aspect of the electric blower according to the present disclosure includes a rotor having a rotating shaft and a rotor core, a motor case that houses the rotor, and a rotating fan that is attached to the rotating shaft and sucks outside air. and a cooling fan that is attached to the rotary shaft and cools the inner space of the motor case, wherein the rotation of the cooling fan and the first ventilation passage through which the airflow generated by the rotation of the rotary fan flows a second ventilation passage through which the generated airflow flows, wherein the cooling fan is positioned between the rotating fan and the rotor core, and the cooling fan includes a plurality of first fan blades provided on the rotor core side. , and a plurality of second fan blades provided on the side opposite to the rotor core side.

The cooling fan is preferably a resin molded product.

The height of the first fan blade and the height of the second fan blade are preferably the same.

It is preferable that the electric blower further include a stator that is arranged to surround the rotor core, and that the stator has a wall located on the side of the cooling fan.

It is preferable that the stator has a stator core and a winding coil wound around the stator core via an insulator, and the wall portion is a part of the insulator.

The outer diameter dimension of the cooling fan is preferably equal to the outer diameter dimension of the rotor core.

The electric blower has an air intake, further includes a fan case covering the rotating fan, a bracket positioned between the rotating fan and the cooling fan, and the first air passage and the second air passage. and are preferably separated by the brackets.

It is preferable to further include an air guide that covers the bracket.

The bracket includes a step on the outer periphery. Preferably, the fan case is in contact with the step.

The bracket may have ribs, and the ribs may protrude toward the cooling fan.

The electric blower preferably further has a cover that covers the ribs.

Further, one aspect of the cooling fan according to the present disclosure is the cooling fan attached to the rotating shaft in the electric blower described above, wherein the electric blower is a bypass type blower motor and is provided on one surface side. and the plurality of second fan blades provided on the side opposite to the one surface side.

According to the present disclosure, deformation of the cooling fan can be suppressed, and an increase in noise can be suppressed.

FIG. 1 is an external perspective view of an electric blower according to Embodiment 1. FIG. FIG. 2 is a cross-sectional view of the electric blower according to Embodiment 1 in an XZ cross section taken along a plane passing through the axis of the rotating shaft. FIG. 3 is a cross-sectional view of the electric blower according to Embodiment 1 in the YZ cross section taken along a plane passing through the axis of the rotating shaft. FIG. 4A is a perspective view of the cooling fan mounted on the electric blower according to Embodiment 1 as viewed obliquely from above. FIG. 4B is a perspective view of the cooling fan mounted on the electric blower according to Embodiment 1 when viewed obliquely from below. 5A is a top view showing a configuration of a cooling fan mounted on the electric blower according to Embodiment 1. FIG. 5B is a side view showing the configuration of the cooling fan mounted on the electric blower according to Embodiment 1. FIG. 6 is a cross-sectional view of an electric blower of Comparative Example 1. FIG. 7A is a perspective view of a cooling fan mounted on an electric blower of Comparative Example 1. FIG. 7B is a side view of a cooling fan mounted on the electric blower of Comparative Example 1. FIG. FIG. 8 is a cross-sectional view of the electric blower according to Embodiment 2 in the XZ cross section taken along a plane passing through the axis of the rotating shaft. FIG. 9 is a perspective view showing an air guide of an electric blower according to Embodiment 2. FIG. 10 is a perspective view showing a bracket of an electric blower according to Embodiment 2. FIG. FIG. 11 is a cross-sectional view of the electric blower according to Embodiment 3 in the XZ cross section taken along a plane passing through the axis of the rotating shaft. 12 is a perspective view showing an air guide of an electric blower according to Embodiment 3. FIG. FIG. 13 is a cross-sectional view of the electric blower according to Embodiment 4 in the XZ cross section taken along a plane passing through the axis of the rotating shaft. 14 is a perspective view showing a cover of an electric blower according to Embodiment 4. FIG. FIG. 15 is a cross-sectional view of the electric blower according to Comparative Example 2 in an XZ cross section taken along a plane passing through the axis of the rotating shaft. FIG. 16 is a cross-sectional view of the electric blower according to Comparative Example 3 in an XZ cross section taken along a plane passing through the axis of the rotating shaft. FIG. 17 is a top view of a cooling fan according to a modification.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. It should be noted that each of the embodiments described below is a specific example of the present disclosure. Therefore, numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection forms, and the like shown in the following embodiments are examples and are not intended to limit the present disclosure. Therefore, among constituent elements in the following embodiments, constituent elements not described in independent claims will be described as optional constituent elements.

In addition, in this specification and drawings, the X-axis, Y-axis and Z-axis represent three axes of a three-dimensional orthogonal coordinate system. The X-axis and the Y-axis are orthogonal to each other and both orthogonal to the Z-axis. In the present embodiment, the Z-axis direction is the direction in which the axis C of the rotating shaft 13 extends.

It should be noted that each figure is a schematic diagram and is not necessarily strictly illustrated. Moreover, in each figure, the same code|symbol is attached|subjected to the substantially same structure, and the description is used. Also, in this specification, the terms "upper" and "lower" do not necessarily indicate upward (vertically upward) and downward (vertically downward) directions in absolute spatial recognition.

(Embodiment 1)
First, the overall configuration of an electric blower 1 according to Embodiment 1 will be described with reference to FIGS. 1 to 3. FIG. FIG. 1 is an external perspective view of an electric blower 1 according to Embodiment 1. FIG. FIG. 2 is a cross-sectional view of the electric blower 1 according to Embodiment 1 in the XZ cross section taken along a plane passing through the axis C of the rotating shaft 13. FIG. FIG. 3 is a cross-sectional view of the electric blower 1 according to Embodiment 1 in the YZ cross section taken along a plane passing through the axis C of the rotating shaft 13 . 2 and 3 mainly show only line drawings appearing in the cross section. The thick arrows shown in FIG. 3 indicate the flow of air.

As shown in FIGS. 1 to 3, the electric blower 1 includes a motor 10, a centrifugal fan 20 and a cooling fan 70 which are rotating fans, an air guide 30, a fan case 40, a motor case 50, and a bracket 60. Prepare. Motor 10 has a rotor 11 and a stator 12 . Centrifugal fan 20 and cooling fan 70 are attached to rotary shaft 13 of motor 10 . Air discharged from the centrifugal fan 20 flows into the air guide 30 . A fan case 40 covers the centrifugal fan 20 and the air guide 30 . Motor case 50 accommodates motor 10 . Bracket 60 covers motor case 50 .

The electric blower 1 according to Embodiment 1 is a bypass type blower motor. That is, the electric blower 1 has a cooling fan 70 for cooling the internal parts of the motor 10 separately from the centrifugal fan 20 that sucks the outside air as the main function of the electric blower 1 . The electric blower 1, which is a bypass type blower motor, has a first ventilation path R1 through which the air current generated by the rotation of the centrifugal fan 20 flows, and a second ventilation path R2 through which the air current generated by the rotation of the cooling fan 70 flows. are separated. The first ventilation path R1 and the second ventilation path R2 are spatially separated without intersecting each other. In other words, airflow does not come and go between the first ventilation path R1 and the second ventilation path R2.

The electric blower 1 can be used, for example, in a vacuum cleaner. As an example, the electric blower 1, which is a bypass type blower motor, is used in a commercial rechargeable dry/wet vacuum cleaner.

The motor 10 is an electric motor that rotates the centrifugal fan 20. As an example, the motor 10 is a direct current motor that receives a direct current power supply. Motor 10 is a brushed commutator motor.

Specifically, the motor 10 includes a rotor 11 , a stator 12 , a rotating shaft 13 , a commutator 14 , brushes 15 , a first bearing 16 and a second bearing 17 .

The rotor 11 (rotor) has a rotating shaft 13 . The rotor 11 rotates around the rotating shaft 13 by the magnetic force of the stator 12 . The rotor 11 is an inner rotor. The rotor 11 is arranged inside the stator 12 as shown in FIGS. Specifically, the rotor 11 is surrounded by the stator 12 with a small air gap therebetween.

The rotor 11 is an armature. The rotor 11 has a rotor core 11a (rotor core) and winding coils 11b (rotor coils) wound around the rotor core 11a. In addition, in FIG.2 and FIG.3, the winding coil 11b is shown typically. The rotor core 11a is a magnetic body made of a magnetic material. As an example, the rotor core 11a is a laminate in which a plurality of electromagnetic steel sheets are laminated in the direction in which the axis C of the rotating shaft 13 extends (axial direction). The rotor core 11a has a plurality of radially projecting teeth. Each tooth generates a magnetic force that acts on the stator 12 by the current flowing through the winding coil 11b.

The stator 12 (stator) is arranged to face the rotor 11 . The stator 12 generates magnetic force acting on the rotor 11 . Stator 12 is arranged to surround rotor 11 . Specifically, the stator 12 is arranged so as to surround a rotor core 11 a of the rotor 11 . The stator 12 forms a magnetic circuit together with the rotor 11, which is an armature. The stator 12 is fixed to the motor case 50, for example.

The stator 12 is configured such that N poles and S poles alternately appear on the air gap surface in the circumferential direction. As shown in FIG. 3, the stator 12 has a stator core 12a and winding coils 12b (stator coils). The stator core 12a has a plurality of teeth that generate main magnetic flux. A winding coil 12b (stator coil) is wound around the stator core 12a via an insulator 12c.

The stator core 12 a is, for example, a laminate in which a plurality of electromagnetic steel sheets are laminated in the direction of the axis C of the rotating shaft 13 . The stator core 12a faces the rotor core 11a. Specifically, the stator core 12a surrounds the rotor core 11a. The winding coil 12b is wound around each of the plurality of teeth of the stator core 12a. The insulator 12c is an insulating frame that covers the stator core 12a. Specifically, the insulator 12c covers the teeth of the stator core 12a. Therefore, the winding coil 12b is wound around an insulator 12c covering the teeth. That is, the insulator 12c is a winding frame around which the winding coil 12b is wound. The insulator 12c is made of, for example, an insulating resin material such as polybutylene terephthalate (PBT).

Note that the stator 12 may be composed of permanent magnets. In this case, the stator 12 has, for example, a plurality of permanent magnets arranged so that N poles and S poles appear alternately along the circumferential direction.

As shown in FIG. 3, the stator 12 has a wall portion 12d located on the side of the cooling fan 70. As shown in FIG. The wall portion 12d is part of the insulator 12c. That is, the wall portion 12d is formed integrally with the insulator 12c. A plurality of wall portions 12d are provided along the circumferential direction. For example, the wall portions 12d are arcuate with a central angle of about 20° to 100° when viewed from above, and are provided in pairs so as to face each other. Three or more wall portions 12d may be formed along the circumferential direction.

The rotating shaft 13 is a shaft that serves as the center when the rotor 11 rotates. The rotating shaft 13 extends in the longitudinal direction, which is the axial center C direction. The rotating shaft 13 is, for example, a metal rod. The rotating shaft 13 is fixed to the rotor 11 . Specifically, the rotating shaft 13 is fixed to the rotor core 11a of the rotor 11, for example, while passing through the center of the rotor core 11a. As an example, the rotary shaft 13 is fixed to the rotor core 11a by press-fitting or shrink fitting into a center hole provided in the rotor core 11a.

A first end 13 a (the end on the side of the centrifugal fan 20 ), which is one end of the rotating shaft 13 , is supported by a first bearing 16 . A first end 13 a of the rotating shaft 13 protrudes from the first bearing 16 . A centrifugal fan 20 is attached to the tip of the rotating shaft 13 protruding from the first bearing 16 . The first bearing 16 is fixed to the bracket 60 .

On the other hand, the second end 13b, which is the other end of the rotating shaft 13, is supported by the second bearing 17. As shown in FIG. The second bearing 17 is fixed to the bottom of the motor case 50 . Thus, the rotary shaft 13 is supported by the first bearing 16 and the second bearing 17 so as to be rotatable. As an example, the first bearing 16 and the second bearing 17 are ball bearings. However, it is not limited to this.

In addition, in the rotary shaft 13, the portion to which the centrifugal fan 20 is attached (the portion on the side of the first bearing 16) is called an output shaft, and the portion on the side opposite to the side of the centrifugal fan 20 (the portion on the side of the second bearing 17). is called the anti-output shaft.

The commutator 14 is attached to the rotating shaft 13 . Therefore, the commutator 14 rotates together with the rotating shaft 13 . The commutator 14 is positioned closer to the second bearing 17 than the rotor core 11a in the axial center C direction. Specifically, the commutator 14 is attached to a portion of the rotating shaft 13 between the rotor core 11 a and the second bearing 17 .

The commutator 14 has a plurality of commutator segments arranged in an annular shape so as to surround the rotating shaft 13 . The plurality of commutator segments are insulated and separated from each other in the rotating direction of the rotating shaft 13 . Each of the multiple commutator segments is electrically connected to the winding coil 11b of the rotor 11 .

As shown in FIG. 2, the commutator 14 is in contact with the brushes 15 . The brushes 15 are power supply brushes for supplying power to the rotor 11 by contacting the commutator 14 . Specifically, the brushes 15 supply the armature current to the winding coils 11b of the rotor 11 via the commutator 14 by coming into contact with the commutator pieces of the commutator 14 . As an example, the brush 15 is a conductive carbon brush made of carbon. The brush 15 is an elongated substantially rectangular parallelepiped.

The brush 15 is arranged so as to be slidably contactable with the commutator 14 . In this embodiment, a pair of brushes 15 are provided. A pair of brushes 15 are arranged to face each other with the commutator 14 interposed therebetween. Specifically, the inner tip of each of the pair of brushes 15 is in contact with the commutator 14 . The brush 15 receives a pressing force from a brush spring such as a torsion spring and is in sliding contact with the commutator 14 . The brush 15 is housed, for example, in a brush holder.

The centrifugal fan 20 is an example of a rotating fan, and sucks air by rotating. Specifically, the centrifugal fan 20 sucks air into an outer casing (housing) composed of the fan case 40 and the motor case 50 . In the present embodiment, air is sucked into the space area between fan case 40 and bracket 60 . A high suction pressure can be obtained by using the centrifugal fan 20 as the rotating fan.

The centrifugal fan 20 is attached to the first end 13a of the rotating shaft 13 of the motor 10, and rotates as the rotating shaft 13 rotates. The centrifugal fan 20 is fixed to the tip of the rotary shaft 13 on the first end 13a side. The centrifugal fan 20 is fixed to the rotating shaft 13 by, for example, press-fitting the rotating shaft 13 into a through hole provided in the centrifugal fan 20 . Note that the method of fixing the centrifugal fan 20 and the rotating shaft 13 is not limited to this. For example, the centrifugal fan 20 may be pressurized and held on the rotating shaft 13 by being inserted into the rotating shaft 13 together with the fastening nut and the mounting plate and tightening the fastening nut.

The centrifugal fan 20 has an intake port 20a (intake port) for sucking air and an exhaust port 20b (outlet) for blowing out the air sucked from the intake port 20a. The air intake port 20 a is a circular opening provided in the central portion of the centrifugal fan 20 . A plurality of exhaust ports 20 b are provided on the side of the centrifugal fan 20 .

The centrifugal fan 20 includes a first side plate 21 (first fan plate) provided with an air intake port 20a, and a second side plate 22 (second fan plate) facing the first side plate 21 with a predetermined gap therebetween. plate) and a plurality of fan blades 23 arranged between the first side plate 21 and the second side plate 22 .

The first side plate 21 is a shroud located on the upstream side. The first side plate 21 is a flat, substantially truncated cone-shaped tubular body. The intake port 20 a is provided at the top of the first side plate 21 . The second side plate 22 is a hub positioned downstream. The second side plate 22 is a flat circular flat plate. The plurality of fan blades 23 are blades sandwiched between the first side plate 21 and the second side plate 22 . The plurality of fan blades 23 are plate-shaped members each curved in an arc shape, and are arranged radially. The plurality of fan blades 23 are arranged in a spiral shape at regular intervals.

A space surrounded by four surfaces of the two adjacent fan blades 23, the first side plate 21, and the second side plate 22 is a ventilation passage through which the air that has flowed into the centrifugal fan 20 from the air inlet 20a passes. An opening on the radially outer side of this ventilation passage serves as an exhaust port 20b.

The first side plate 21, the second side plate 22 and the plurality of fan blades 23 are made of metal plates made of aluminum, for example. The plurality of fan blades 23 are fixed to the first side plate 21 and the second side plate 22 by caulking.

The centrifugal fan 20 is arranged above the bracket 60 . Specifically, centrifugal fan 20 is arranged between fan case 40 and bracket 60 .

Wind pressure is generated by the rotation of the centrifugal fan 20, and air is sucked from the air intake port 40a of the fan case 40. Specifically, when the centrifugal fan 20 rotates, the vicinity of the exhaust port 20b of the centrifugal fan 20 becomes high pressure to generate suction pressure, and external air is sucked through the intake port 40a of the fan case 40 . The air sucked into the fan case 40 is sucked from the air inlet 20 a of the centrifugal fan 20 , blown out from the air outlet 20 b, and flows into the air guide 30 . That is, air discharged from the centrifugal fan 20 flows into the air guide 30 .

The air guide 30 has the function of rectifying the flow of air discharged from the centrifugal fan 20 and discharging it to the outside of the electric blower 1 . Specifically, the air guide 30 guides the air compressed by the centrifugal fan 20 to the outside of the electric blower 1 while gradually returning the pressure to atmospheric pressure. The air guide 30 is formed in a substantially annular shape as a whole. Air guide 30 is arranged to surround centrifugal fan 20 . Air guide 30 is arranged between fan case 40 and motor case 50 . Specifically, the air guide 30 is arranged between the fan case 40 and the bracket 60 . The air guide 30 is made of, for example, a resin material. However, the air guide 30 may be made of a metal material.

The air guide 30 has a plurality of diffuser wings 31. The plurality of diffuser blades 31 each have a plate shape curved in an arc shape and are erected. Specifically, the plurality of diffuser blades 31 are arranged in a spiral shape so as to spiral as a whole. The air that has flowed into the air guide 30 is exhausted to the outside of the electric blower 1 through a plurality of diffuser air passages formed by a plurality of diffuser blades 31 . This diffuser air passage is part of the first air passage R1.

The fan case 40 is a cover that covers the centrifugal fan 20 and the air guide 30. Fan case 40 also covers bracket 60 . The fan case 40 has a lid portion 41 (first fan case portion) and a side wall portion 42 (second fan case portion). The lid portion 41 covers the upper portions of the centrifugal fan 20 and the air guide 30 . The side wall portion 42 covers lateral portions of the centrifugal fan 20 and the air guide 30 . The fan case 40 is, for example, a metal cover made of a metal material. However, it is not limited to this.

The fan case 40 has an intake port 40a (intake port) for sucking outside air. The intake port 40 a is a circular through hole provided in the central portion of the lid portion 41 . The intake port 40 a of the fan case 40 faces the intake port 20 a of the centrifugal fan 20 . As the centrifugal fan 20 rotates, air flows into the fan case 40 from the air inlet 40 a of the fan case 40 .

The fan case 40 is fixed to the bracket 60. Specifically, as shown in FIG. 2, the fan case 40 and the bracket 60 are fixed by connecting the side wall portion 42 of the fan case 40 and the outer peripheral end portion of the bracket 60 .

A fan case spacer 80 is attached to the fan case 40 . Specifically, fan case spacer 80 is attached to fan case 40 so as to surround air inlet 40 a of fan case 40 . By providing the fan case spacer 80, the blowing efficiency of the electric blower 1 can be improved as compared with the case where the fan case spacer 80 is not provided.

The motor case 50 is a housing (frame) that houses the motor 10 . Specifically, the motor case 50 houses the parts that make up the motor 10 such as the rotor 11 and the stator 12 . The motor case 50 is an outer shell member (outer shell) of the electric blower 1 and the motor 10 . The motor case 50 is, for example, a metal case made of a metal material.

The motor case 50 has a bottomed cylindrical shape with an opening. Motor case 50 has a bottom and a cylindrical side wall. The opening of the cylindrical portion of motor case 50 is covered with bracket 60 and fan case 40 .

A plurality of through holes 50a are formed in the bottom and side walls of the motor case 50. The plurality of through-holes 50a are intake ports (intake ports) for sucking air from the outside of the motor case 50 as the cooling fan 70 rotates. The air sucked from the through hole 50 a flows between the stator core 12 a and the rotor core 11 a and between the stator core 12 a and the motor case 50 to flow through the inside of the motor case 50 toward the bracket 60 side. The air that has flowed to the bracket 60 side inside the motor case 50 is discharged to the outside through a gap formed between the bracket 60 and the motor case 50 . At this time, the gap 50b formed between the bracket 60 and the motor case 50 functions as an exhaust port (air outlet).

The motor case 50 also functions as a bracket that holds the second bearing 17. Therefore, the motor case 50 has a bearing holder 51 that holds the second bearing 17 . The bearing holding portion 51 is provided on the bottom portion of the motor case 50 . The second bearing 17 is fixed to the bearing holding portion 51 by, for example, adhesion.

The bracket 60 has a bearing holding portion 61 that holds the first bearing 16 . The first bearing 16 is fixed to the bearing holding portion 61 by, for example, adhesion. Bracket 60 is arranged to cover the opening of the cylindrical portion of motor case 50 .

The bracket 60 divides the space area surrounded by the fan case 40 and the motor case 50 into upper and lower parts. An upper first space area surrounded by the fan case 40 and the bracket 60 is a first ventilation path R1 through which the airflow generated by the rotation of the centrifugal fan 20 flows. A centrifugal fan 20 is arranged in this first space area. On the other hand, the lower second space area surrounded by the bracket 60 and the motor case 50 is the second ventilation path R2 through which the airflow generated by the rotation of the cooling fan 70 flows. A cooling fan 70 is arranged in this second spatial region. Therefore, bracket 60 is arranged between centrifugal fan 20 and cooling fan 70 . The bracket 60 separates the first ventilation passage R1 through which the air current from the centrifugal fan 20 flows and the second ventilation passage R2 through which the air current from the cooling fan 70 flows. That is, the bracket 60 has a function of separating the first ventilation path R1 and the second ventilation path R2.

As shown in FIGS. 1 and 3, the outer peripheral edge of the bracket 60 is provided with a plurality of exhaust ports 60a (blowout ports) for blowing out the air sucked in by the rotation of the centrifugal fan 20. As shown in FIG. That is, the exhaust port 60 a is a through hole for exhausting the air sucked into the fan case 40 by the centrifugal fan 20 to the outside of the electric blower 1 . As shown in FIG. 1, the plurality of exhaust ports 60a are arranged at equal intervals along the circumferential direction at the outer peripheral edge of the bracket 60. As shown in FIG. A plurality of exhaust ports 60a are provided, for example, for each diffuser air passage formed by two adjacent diffuser blades 31 . However, it is not limited to this.

The cooling fan 70 is an example of a rotating fan. Cooling fan 70 is attached to rotating shaft 13 of motor 10 . Therefore, cooling fan 70 rotates as rotating shaft 13 rotates. Since centrifugal fan 20 is also attached to rotary shaft 13 , cooling fan 70 rotates in conjunction with centrifugal fan 20 positioned above bracket 60 .

The cooling fan 70 is arranged below the bracket 60 in the axial center C direction. Therefore, cooling fan 70 faces centrifugal fan 20 via bracket 60 . Cooling fan 70 is arranged between bracket 60 and rotor core 11 a of rotor 11 . That is, the cooling fan 70 is positioned between the centrifugal fan 20 and the rotor core 11 a of the rotor 11 in the axial center C direction of the rotating shaft 13 .

Here, the detailed configuration of the cooling fan 70 will be described using FIGS. 4A, 4B and 5 while referring to FIGS. 2 and 3. FIG. FIG. 4A is a perspective view of cooling fan 70 mounted on electric blower 1 according to Embodiment 1, viewed obliquely from above. FIG. 4B is a perspective view of the cooling fan 70 mounted on the electric blower 1 according to Embodiment 1 as viewed obliquely from below. FIG. 5A is a top view showing the configuration of cooling fan 70 mounted on electric blower 1 according to Embodiment 1. FIG. 5B is a side view showing the configuration of cooling fan 70 mounted on electric blower 1 according to Embodiment 1. FIG.

As shown in FIGS. 4A, 4B, 5A, and 5B, the cooling fan 70 has a plurality of first fan blades 71, a plurality of second fan blades 72, and a base portion 73.

The base portion 73 is disc-shaped. The base portion 73 has a first surface 73a and a second surface 73b facing the first surface 73a. The first surface 73a of the base portion 73 is the upper side (bracket 60 side), and the second surface 73b of the base portion 73 is the lower side.

A through hole 74 into which the rotating shaft 13 is inserted is formed in the central portion of the base portion 73 . Specifically, a cylindrical portion in which a through hole 74 is formed is provided in the central portion of the base portion 73 . By press-fitting the rotating shaft 13 into the through hole 74 , the cooling fan 70 can be fixed at a predetermined position on the rotating shaft 13 .

The cooling fan 70 has double-sided blade specifications. The cooling fan 70 has a plurality of first fan blades 71 provided on one side and a plurality of second fan blades 72 provided on the other side in the direction of the axis C of the rotating shaft 13 .

The plurality of first fan blades 71 are provided on the side of the base portion 73 opposite to the rotor core 11a side (that is, on the side of the centrifugal fan 20). Specifically, the plurality of first fan blades 71 are provided so as to protrude from the first surface 73a of the base portion 73 and extend like ridges on the first surface 73a. The plurality of first fan blades 71 are arranged at equal intervals in the circumferential direction and arranged radially. Each of the plurality of first fan blades 71 has a curved portion. The plurality of first fan blades 71 are arranged in a spiral so as to spiral. All of the plurality of first fan blades 71 have the same shape. However, it is not limited to this.

The plurality of second fan blades 72 are provided on the rotor core 11a side of the base portion 73 . Specifically, the plurality of second fan blades 72 are provided on the second surface 73b of the base portion 73 so as to protrude from the second surface 73b. The plurality of second fan blades 72 are also arranged at equal intervals in the circumferential direction and arranged radially. Each of the plurality of second fan blades 72 has a curved portion. The plurality of second fan blades 72 are arranged in a spiral so as to spiral. All of the plurality of second fan blades 72 have the same shape. However, it is not limited to this.

Each of the first fan blades 71 and the second fan blades 72 is formed so as to extend radially outward from the central portion of the cooling fan 70 and curve halfway. The first fan blades 71 and the second fan blades 72 are curved in the same direction. The first fan blades 71 and the second fan blades 72 are curved in the same direction as the fan blades 23 of the centrifugal fan 20 . Each of the first fan blades 71 and the second fan blades 72 extends with a constant width.

As shown in FIG. 5A, when the cooling fan 70 is viewed from above, the first fan blades 71 and the second fan blades 72 are alternately arranged one by one. That is, the first fan blades 71 are arranged so as to be positioned between two adjacent second fan blades 72 . Similarly, the second fan blades 72 are arranged so as to be positioned between two adjacent first fan blades 71 .

The width of the first fan blade 71 and the width of the second fan blade 72 are the same. The height of the first fan blades 71 and the height of the second fan blades 72 are the same. Specifically, the first fan blades 71 and the second fan blades 72 have the same shape.

The cooling fan 70 configured in this manner is a resin molded product that is integrally molded from a resin material. That is, the first fan blades 71, the second fan blades 72, and the base portion 73 are integrally formed of resin. As the resin constituting the cooling fan 70, a lightweight resin such as Polybutylene Terephthalate (PBT), Polyethylene Terephthalate (PET), or Polypropylene (PP) can be used. The resin forming the cooling fan 70 may contain a reinforcing material such as a glass filler. Thereby, the strength of the cooling fan 70 can be improved.

As shown in FIGS. 2 and 3, the outer diameter of the cooling fan 70 is smaller than the outer diameter of the centrifugal fan 20. The outer diameter dimension of the cooling fan 70 is the same as the outer diameter dimension of the rotor core 11 a of the rotor 11 . The cooling fan 70 is positioned on the side of the wall portion 12 d of the stator 12 . Specifically, the cooling fan 70 is surrounded by the wall portion 12 d of the stator 12 . Since a pair of wall portions 12d are provided facing each other, the cooling fan 70 is sandwiched between the pair of wall portions 12d. The upper end of the wall portion 12d is preferably located above the first surface 73a (upper surface) of the base portion 73 of the cooling fan 70, and is located above the upper ends of the first fan blades 71 of the cooling fan 70. It's even better when you're there.

In the electric blower 1 configured as described above, when the motor 10 is driven to rotate the rotor 11, the centrifugal fan 20 and the cooling fan 70 attached to the rotation shaft 13 of the rotor 11 rotate.

In this case, as the centrifugal fan 20 rotates, an airflow is generated in the first ventilation passage R1. Specifically, air is sucked into the fan case 40 from the intake port 40a of the fan case 40, as indicated by the thick arrow in FIG. The air sucked from the air intake port 40a of the fan case 40 is exhausted to the outside of the electric blower 1 through the plurality of air outlets 60a of the bracket 60 through the first air passage R1. Therefore, the inlet of the first ventilation path R1 is the intake port 40a of the fan case 40. As shown in FIG. The outlet of the first ventilation path R1 is the exhaust port 60a of the bracket 60. As shown in FIG.

Specifically, when the centrifugal fan 20 rotates, the air sucked from the air inlet 40 a of the fan case 40 flows into the centrifugal fan 20 from the air inlet 20 a of the centrifugal fan 20 . The air that has flowed into the centrifugal fan 20 is blown radially outward of the centrifugal fan 20 and exhausted from the exhaust port 20b. At this time, the air sucked into the centrifugal fan 20 is compressed to a high pressure by the centrifugal fan 20 . Air exhausted from the centrifugal fan 20 flows into an air guide 30 surrounding the centrifugal fan 20 . The air that has flowed into the air guide 30 is decelerated as it passes through the diffuser ventilation passage whose cross-sectional area gradually increases, and the pressure drops. It is folded back by the ventilation channel. The folded air is discharged to the outside of the electric blower 1 from the exhaust port 60 a of the bracket 60 .

On the other hand, as the cooling fan 70 rotates, an airflow is generated in the second ventilation passage R2. Specifically, as indicated by the thick arrow in FIG. 3 , air is sucked into the motor case 50 through the through hole 50a by the rotation of the cooling fan 70 . The sucked air generates an airflow inside the motor case 50 as the cooling fan 70 rotates. The airflow generated inside the motor case 50 moves inside the motor case 50 toward the bracket 60 side through the second ventilation path R2. The air flowing through the motor case 50 toward the bracket 60 is discharged to the outside of the electric blower 1 through a gap 50 b formed between the motor case 50 and the bracket 60 . That is, the entrance of the second ventilation path R2 is the through hole 50a of the motor case 50, and the exit of the second ventilation path R2 is the gap 50b.

Specifically, when the cooling fan 70 rotates, an airflow is generated inside the motor case 50 from the through-hole 50a to the gap 50b. The generated airflow passes through the second ventilation path R2 while cooling internal parts of the motor 10 such as the rotor 11 and the stator 12 . The air sucked through the through hole 50 a of the motor case 50 is discharged to the outside of the electric blower 1 together with the heat extracted from the internal parts of the motor 10 .

Here, the effect of the electric blower 1 according to the present embodiment will be described in comparison with the electric blower 1X of Comparative Example 1. FIG. 6 is a cross-sectional view of an electric blower 1X of Comparative Example 1. FIG. 7A is a perspective view of a cooling fan 70X mounted in an electric blower 1X of Comparative Example 1, and FIG. 7B is a side view of the same cooling fan 70X.

As shown in FIG. 6, the electric blower 1X of Comparative Example 1 is a bypass type blower motor, and differs from the electric blower 1 according to the above embodiment only in the configuration of the cooling fan 70X. Specifically, as shown in FIGS. 7A and 7B, a cooling fan 70X mounted in an electric blower 1X of Comparative Example 1 (cooling fan of Comparative Example 1) has fan blades 71X on only one side on the motor 10 side. It has a single-sided wing specification.

In the electric blower 1X of Comparative Example 1, when the cooling fan 70X rotates at high speed together with the centrifugal fan 20, stress is generated in the fan blades 71X of the cooling fan 70X, and the fan blades 71X may be deformed. In this case, even the base portion 73X that holds the fan blades 71X may be deformed, and the fan blades 71X may come into contact with internal parts of the electric blower 1X. For example, the base portion 73X may deform and a portion of the deformed base portion 73X may come into contact with the bracket 60 .

Therefore, in order to prevent the cooling fan 70X from deforming during high-speed rotation, it is conceivable to construct the cooling fan 70X with a metal material to increase its strength. However, if the cooling fan 70X is made of a metal material, the weight of the cooling fan 70X increases or the weight is unbalanced, resulting in reduced efficiency and vibration.

The cooling fan 70X of Comparative Example 1 has fan blades 71X only on one side. Accordingly, it is necessary to increase the height of the fan blades 71X in order to increase the amount of cooling air. However, if the fan blades 71X of the cooling fan 70X are raised, not only will the fan blades 71X be easily deformed, but also the noise caused by the rotation of the cooling fan 70X will increase.

On the other hand, the cooling fan 70 mounted on the electric blower 1 according to the present embodiment has double-sided blade specifications. Thus, the cooling fan 70 has a plurality of first fan blades 71 provided on one side and a plurality of second fan blades 72 provided on the other side in the direction of the axis C of the rotating shaft 13 .

With this configuration, when the cooling fan 70 rotates at high speed, the stresses generated in the first fan blades 71 and the second fan blades 72 cancel each other out. As a result, deformation of the cooling fan 70 can be suppressed compared to the cooling fan 70X with single-sided blade specifications. As a result, it is possible to prevent a portion of the deformed cooling fan 70 from contacting the bracket 60 and the like.

As a result, even if the cooling fan 70 is formed of a resin material instead of being made of a metallic material as in the present embodiment, the deformation of the cooling fan 70 can be prevented. can be suppressed. Moreover, deformation of the cooling fan 70 can be suppressed even if the cooling fan 70, which is a resin molded product, does not contain a glass filler or the like. In other words, the cooling fan 70 has high strength even if it is a resin molded product.

By making the cooling fan 70 a resin molded product in this way, the weight of the cooling fan 70 can be reduced and weight imbalance can be suppressed compared to the case where the cooling fan 70 is made of a metal material. As a result, the weight of the electric blower 1 can be reduced, and the vibration of the electric blower 1 can be suppressed.

Moreover, like the cooling fan 70 in this embodiment, by providing a plurality of first fan blades 71 on one side and providing a plurality of second fan blades 72 on the other side, the first fan blades 71 and the second The cooling air volume can be ensured without increasing the height of the fan blades 72 too much.

Regarding this point, according to the experimental results of the inventors, the sum of the height of the first fan blades 71 and the height of the second fan blades 72 is equal to the height of the fan blades 71X of the cooling fan 70X of Comparative Example 1. It was confirmed that a cooling air volume equivalent to that of the cooling fan 70X of Comparative Example 1 can be ensured by making the height equivalent. That is, even if the height of each of the first fan blades 71 and the second fan blades 72 is half the height of the fan blades 71X of the cooling fan 70X of the comparative example 1, the cooling air volume of the cooling fan 70 is the same as that of the comparative example. The amount of cooling air can be made equivalent to that of one cooling fan 70X.

Thus, in the electric blower 1 using the cooling fan 70 according to the present embodiment, the height of each of the first fan blades 71 and the second fan blades 72 is low. Therefore, compared with the electric blower 1X using the cooling fan 70X of Comparative Example 1, the noise caused by the cooling fan 70 can be reduced while maintaining the efficiency.

As described above, the electric blower 1 according to the present embodiment includes the rotor 11, the motor case 50, the centrifugal fan 20 which is a rotating fan, and the cooling fan . The rotor 11 has a rotating shaft 13 and a rotor core 11a. The motor case 50 accommodates the rotor 11 . A centrifugal fan 20, which is a rotating fan, is attached to the rotating shaft 13 and sucks outside air. Cooling fan 70 is attached to rotating shaft 13 and cools the internal space of motor case 50 . The electric blower 1 includes a first ventilation passage R1 and a second ventilation passage R2. An air current generated by the rotation of the centrifugal fan 20 flows through the first air passage R1. An air current generated by the rotation of the cooling fan 70 flows through the second ventilation path R2. Cooling fan 70 is positioned between centrifugal fan 20 and rotor core 11a. The cooling fan 70 has a plurality of first fan blades 71 and a plurality of second fan blades 72 . The plurality of first fan blades 71 are provided on the rotor core 11a side. A plurality of second fan blades 72 are provided on the side opposite to the rotor core 11a side.

Therefore, even if the weight of the cooling fan 70 is reduced, deformation of the cooling fan 70 can be suppressed. At the same time, it is possible to suppress an increase in noise while maintaining the efficiency of the electric blower 1 . Therefore, it is possible to realize the electric blower 1 that can meet the demands for weight reduction, high efficiency, and low noise for the commutator motor.

Also, in the electric blower 1 according to the present embodiment, the height of the first fan blades 71 and the height of the second fan blades 72 are the same.

With this configuration, the stress generated in the first fan blade 71 and the stress generated in the second fan blade 72 can be balanced. As a result, mutual stresses generated in the first fan blades 71 and the second fan blades 72 can be more canceled out. Therefore, deformation of the cooling fan 70 during high-speed rotation can be further suppressed.

The height of the first fan blades 71 and the height of the second fan blades 72 may be different. In this case, the height of the first fan blades 71 on the bracket 60 side (the centrifugal fan 20 side) should be higher than the height of the second fan blades 72 . As a result, even if the cooling fan 70 is deformed by the stress generated by the first fan blades 71 and the second fan blades 72, the height of the second fan blades 72 is higher than the height of the first fan blades 71. In comparison, the deformed cooling fan 70 can be prevented from coming into contact with the bracket 60 and the like.

In the electric blower 1 according to the present embodiment, the stator 12 has a wall portion 12 d located on the side of the cooling fan 70 . That is, the wall portion 12 d is positioned on the side of the cooling fan 70 .

With this configuration, the wall portion 12d functions as a rectifying plate, so the air volume (cooling air volume) generated by the rotation of the cooling fan 70 can be increased compared to the case where the wall portion 12d is not provided.

In this case, the wall portion 12d of the stator 12 is part of the insulator 12c of the stator 12.

With this configuration, it is possible to increase the amount of cooling air by the cooling fan 70 without providing a separate current plate.

In the electric blower 1 of the present embodiment, the outer diameter dimension of the cooling fan 70 is the same as the outer diameter dimension of the rotor core 11 a of the rotor 11 .

With this configuration, the outer diameter of the cooling fan 70 can be made as large as possible. Therefore, the amount of cooling air by the cooling fan 70 can be increased as much as possible.

In addition, as a result of continuing diligent studies by the inventors, it was found that the performance degradation of the centrifugal fan 20 and the cooling fan 70 can be suppressed by the embodiment described later.

(Embodiment 2)
A configuration of an electric blower 1a according to Embodiment 2 will be described with reference to FIGS. 8 to 10. FIG. The same reference numerals are used for the same components as in the electric blower 1 according to Embodiment 1, and the description thereof is incorporated. FIG. 8 is a cross-sectional view of the electric blower 1a according to the second embodiment in the XZ cross section taken along a plane passing through the axis C of the rotating shaft 13. FIG.

The difference between the electric blower 1a and the electric blower 1 is that the air guide 30a is configured to cover the bracket 60. FIG. 9 is a perspective view showing the air guide 30a of the electric blower 1a according to the second embodiment. FIG. 10 is a perspective view showing bracket 60 of electric blower 1a according to the second embodiment.

Without the air guide 30 a below the centrifugal fan 20 , the high-speed rotation of the centrifugal fan 20 causes interference between the air rotated by the centrifugal fan 20 and the air existing between the ribs 63 of the bracket 60 . a vortex is generated. As a result, there is a problem that the rotation of the centrifugal fan 20 is hindered. In order to solve this problem, the bracket 60 is covered with the air guide 30a, which has the effect of increasing the output. In other words, the performance of the centrifugal fan 20 can be suppressed from deteriorating by the air guide 30a.

(Embodiment 3)
A configuration of an electric blower 1b according to Embodiment 3 will be described with reference to FIGS. 11 and 12. FIG. The same reference numerals are used for the same components as in the electric blower 1 according to Embodiment 1, and the description thereof is incorporated. FIG. 11 is a cross-sectional view of the electric blower 1b according to the third embodiment in the XZ cross section taken along a plane passing through the axis C of the rotating shaft 13. FIG.

The difference between the electric blower 1b and the electric blower 1 is that the air guide 30b is configured to cover the bracket 60 and the diffuser blades 31 according to the first embodiment are eliminated. FIG. 12 is a perspective view showing the air guide 30b of the electric blower 1a according to the third embodiment.

Without the air guide 30 b below the centrifugal fan 20 , the high-speed rotation of the centrifugal fan 20 causes interference between the air rotated by the centrifugal fan 20 and the air existing between the ribs 63 of the bracket 60 . a vortex is generated. As a result, there is a problem that the rotation of the centrifugal fan 20 is hindered. In order to solve this problem, the bracket 60 is covered with the air guide 30b. In other words, the performance of the centrifugal fan 20 can be suppressed from deteriorating by the air guide 30b.

Also, since the diffuser blades 31 according to the first embodiment are eliminated, the fan case 40 cannot be supported by the diffuser blades 31. However, as shown in FIG. 11, the bracket 60 includes a step 62 on its outer circumference. Fan case 40 contacts step 62 . A stepped portion 62 provided on the outer peripheral portion of the bracket 60 supports the fan case 40 . The mounting position of the fan case 40 is determined by a step 62 . That is, the fan case and the bracket are used in common at the outer peripheral portion of the fan case 40 supported by the step 62 provided on the outer peripheral portion of the bracket 60 . In this way, the outer peripheral portion of the fan case 40 can perform a plurality of functions by changing the minimum number of parts.

(Embodiment 4)
A configuration of an electric blower 1c according to Embodiment 4 will be described with reference to FIGS. 13 and 14. FIG. The same reference numerals are used for the same components as in the electric blower 1 according to Embodiment 1, and the description thereof is incorporated. FIG. 13 is a cross-sectional view of the electric blower 1c according to the fourth embodiment in the XZ cross section taken along a plane passing through the axis C of the rotating shaft 13. FIG.

The difference between the electric blower 1c and the electric blower 1 is that the ribs 63 provided on the bracket 60b protrude toward the cooling fan 70. A cover 35 is provided to cover the rib 63 . FIG. 14 is a perspective view showing the cover 35 of the electric blower 1c according to the fourth embodiment. When the ribs 63 protrude toward the centrifugal fan 20, the high speed rotation of the centrifugal fan 20 causes interference between the air rotated by the centrifugal fan 20 and the air existing between the ribs 63 of the bracket 60. a vortex is generated. As a result, there is a problem that the rotation of the centrifugal fan 20 is hindered. In order to solve this problem, the electric blower 1c is configured such that the ribs 63 provided on the bracket 60b protrude toward the cooling fan 70. As shown in FIG.

Further, if the ribs 63 provided on the bracket 60b project toward the cooling fan 70, the air rotated by the cooling fan 70 and the air existing between the ribs 63 of the bracket 60b interfere with each other to form a vortex. occur. To solve this problem, a cover 35 is provided.

As described above, the ribs 63 provided on the bracket 60b protrude toward the cooling fan 70, and by providing the cover 35 so as to cover the ribs 63, the deterioration of the performance of the centrifugal fan 20 can be suppressed.

Next, the configuration of the electric blower 1Y according to Comparative Example 2 will be described with reference to FIG. The same reference numerals are used for the same components as in the electric blower 1 according to Embodiment 1, and the description thereof is incorporated. FIG. 15 is a cross-sectional view of an electric blower 1Y according to Comparative Example 2 in an XZ cross section taken along a plane passing through the axis C of the rotating shaft 13. As shown in FIG.

The difference between the electric blower 1Y and the electric blower 1 is that the upper and lower surfaces of the bracket 60Y are flat. Thereby, the bracket 60Y serves as the air guide 30a and the bracket 60 of the second embodiment, the air guide 30b and the bracket 60 of the third embodiment, and the bracket 60b and the cover 35 of the fourth embodiment. can be done.

In order to hold the rotating shaft 13 and the first bearing 16, it is generally necessary to increase the thickness of the air guide and bracket to some extent. In Comparative Example 2, the bracket 60Y serves as an air guide and a bracket. Therefore, the bracket 60Y should have a desired thickness. However, if the thickness of the bracket 60Y is simply increased, the bracket itself becomes heavy and the cost increases. Therefore, it is necessary to reduce the weight while maintaining the strength of the bracket. Therefore, in order to reduce the weight of the bracket while maintaining the strength of the bracket, the inventors adopted a configuration in which ribs are formed on the bracket. As a result, deterioration in performance of the centrifugal fan 20 can be suppressed.

Next, the configuration of the electric blower 1Z according to Comparative Example 3 will be described with reference to FIG. The same reference numerals are used for the same components as in the electric blower 1 according to Embodiment 1, and the description thereof is incorporated. FIG. 16 is a cross-sectional view of an electric blower 1Z according to Comparative Example 3 in an XZ cross section taken along a plane passing through the axis C of the rotating shaft 13. FIG.

The difference between the electric blower 1Z and the electric blower 1 is that the ribs of the bracket 60 are removed to form a bracket 60Z. Thereby, the bracket 60Z fulfills the role of the air guide 30a and the bracket 60 of the second embodiment, the role of the air guide 30b and the bracket 60 of the third embodiment, and the role of the bracket 60b and the cover 35 of the fourth embodiment. can be done. However, it is conceivable that the strength of the bracket 60Z is insufficient.

(Modification)
The electric blower according to the present disclosure has been described above based on the embodiment. However, the present disclosure is not limited to the above embodiments.

For example, in the above-described embodiment, the first fan blades 71 and the second fan blades 72 of the cooling fan 70 are formed so as to extend radially outward from the central portion of the cooling fan 70 and curve midway. rice field. However, it is not limited to this. FIG. 17 is a top view of a cooling fan according to a modification. Specifically, like the cooling fan 70A shown in FIG. 17, the first fan blades 71A and the second fan blades 72A extend radially outward from the central portion of the cooling fan 70A. may be formed in

Also, in the above embodiment, a brushed commutator motor is used as the motor 10 used in the electric blower 1 . However, it is not limited to this.

Also, in the above embodiment, the case where the electric blower 1 is used for a vacuum cleaner has been described. However, it is not limited to this. For example, the electric blower 1 may be used for other electrical equipment such as an air towel.

In addition, forms obtained by applying various modifications that a person skilled in the art can think of to the above embodiments, or realized by arbitrarily combining the components and functions in the embodiments within the scope of the present disclosure Forms are also included in this disclosure.

The technology of the present disclosure can be used in various electric devices that use electric blowers.

Reference Signs List 1, 1a, 1b, 1c electric blower 10 motor 11 rotor 11a rotor core 11b, 12b winding coil 12 stator 12a stator core 12c insulator 12d wall 13 rotating shaft 13a first end 13b second end 14 commutator 15 brush 16 th 1 bearing 17 second bearing 20 centrifugal fan (rotating fan)
20a, 40a intake port 20b exhaust port 21 first side plate 22 second side plate 23 fan blades 30, 30a, 30b air guide 31 diffuser blade 35 cover 51, 61 bearing holder 40 fan case 41 lid portion 42 side wall portion 50 motor case 50a Through hole 50b Gap 60, 60b Bracket 60a Exhaust port 62 Step 63 Rib 70, 70A Cooling fan 71, 71A First fan blade 72, 72A Second fan blade 73 Base part 73a First surface 73b Second surface 74 Through hole 80 Fan Case spacer R1 1st ventilation path R2 2nd ventilation path

Claims (12)

1. a rotor having a rotating shaft and a rotor core;
   a motor case that houses the rotor;
   a rotating fan attached to the rotating shaft and sucking outside air;
   a cooling fan attached to the rotating shaft and cooling the internal space of the motor case;
   a first ventilation passage through which airflow generated by rotation of the rotating fan flows; and a second ventilation passage through which airflow generated by rotation of the cooling fan flows;
   The cooling fan is positioned between the rotating fan and the rotor core,
   The cooling fan has a plurality of first fan blades provided on the rotor core side and a plurality of second fan blades provided on a side opposite to the rotor core side,
   electric blower.
2. The cooling fan is a resin molded product,
   The electric blower according to claim 1.
3. the height of the first fan blade and the height of the second fan blade are the same;
   The electric blower according to claim 1 or 2.
4. Further comprising a stator arranged to surround the rotor core,
   The stator has a wall portion located on the side of the cooling fan,
   The electric blower according to any one of claims 1 to 3.
5. The stator has a stator core and a winding coil wound around the stator core via an insulator,
   The wall is part of the insulator,
   The electric blower according to claim 4.
6. The outer diameter dimension of the cooling fan is equivalent to the outer diameter dimension of the rotor core,
   The electric blower according to any one of claims 1 to 4.
7. a fan case having an intake port and covering the rotating fan;
   a bracket positioned between the rotating fan and the cooling fan;
   The first ventilation path and the second ventilation path are separated by the bracket,
   The electric blower according to any one of claims 1 to 6.
8. Further comprising an air guide covering the bracket,
   The electric blower according to claim 7.
9. The bracket includes a step on its outer periphery,
   the fan case is in contact with the step,
   The electric blower according to claim 7.
10. the bracket includes ribs;
    the rib protrudes toward the cooling fan;
    The electric blower according to claim 7.
11. The electric blower according to claim 10, further comprising a cover that covers said rib.
12. The cooling fan attached to the rotating shaft in the electric blower according to any one of claims 1 to 11,
    The electric blower is a bypass type blower motor,
    The plurality of first fan blades provided on one surface side and the plurality of second fan blades provided on the side opposite to the one surface side,
    cooling fan.

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