blower

Abstract

To provide a technology capable of properly cooling an electric motor stored in a motor housing, in a blower.SOLUTION: A blower includes: a blast pipe disposed between an intake port and an exhaust port; an axial fan including a hub and a plurality of blades; a driving shaft; an electric motor; a motor housing; a diffuser cone; a first ventilation hole formed on the diffuser cone; and a second ventilation hole formed between the hub and the motor housing. Inside of the blast pipe, a blast passage to allow the air from the intake port to flow to the exhaust port via the hub, the motor housing, and the outside of the diffuser cone, and a circulation passage to allow the air flowing in the blast passage to pass the inside of the motor housing from the first ventilation hole and to flow out to the blast passage from the second ventilation hole. When a peripheral end portion at an intake port side, of the second ventilation hole is a first end portion, and a peripheral end portion at an exhaust port side, of the second ventilation hole is a second end portion, an outer diameter of the first end portion is larger than an outer diameter of the second end portion.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a blower. [Background technology]

[0002] Patent Document 1 discloses a blower including: an air intake port, an exhaust port, an air duct provided between the air intake port and the exhaust port; an axial fan disposed inside the air duct and including a hub rotatable around a predetermined rotation axis along the extension direction of the air duct; and a plurality of blades provided on an outer surface of the hub; a drive shaft disposed inside the air duct and connected to the axial fan; an electric motor disposed inside the air duct and closer to the exhaust port than the axial fan, and rotatingly driving the drive shaft; a motor housing disposed inside the air duct and accommodating the electric motor; a diffuser cone disposed inside the air duct and connected to the exhaust port side of the motor housing; a first vent provided at an end of the diffuser cone on the exhaust port side; and a second vent provided between the hub and the motor housing along the circumferential direction of the rotation shaft, the second vent having a width in the axial direction of the rotation shaft. The interior of the air duct is formed with an air flow path in which air from the intake port passes through the exterior of the hub, the exterior of the motor housing, and the exterior of the diffuser cone and flows toward the exhaust port, and a circulation path in which air flowing through the air flow path flows from the first air vent port into the interior of the diffuser cone, passes through the interior of the motor housing, and flows out from the second air vent port to the air flow path. When a peripheral end of the second air vent port on the intake port side is defined as a first end and a peripheral end of the second air vent port on the exhaust port side is defined as a second end, the outer diameter of the first end is smaller than the outer diameter of the second end (or the outer diameters of the first end and second end are the same). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2008 / 0219844 Summary of the Invention [Problem to be solved by the invention]

[0004] In the blower of Patent Document 1, the air flowing along the outer surface of the hub is separated from the outer surface of the hub, generating a negative pressure that draws the air through the second air vent into the airflow path (i.e., a negative pressure that generates an air flow in the circulation path). In this way, the blower of Patent Document 1 uses the air flowing along the circulation path as cooling air for the electric motor. However, in the blower of Patent Document 1, the outer diameter of the first end is smaller than the outer diameter of the second end (or the outer diameters of the first end and second end are the same). In this case, the air that separates from the outer surface of the hub immediately reattaches to the outer surface of the motor housing, which may result in insufficient negative pressure and insufficient airflow for cooling the electric motor. For this reason, the blower of Patent Document 1 may not be able to adequately cool the electric motor housed in the motor housing. This specification provides a technology for a blower that can adequately cool an electric motor housed in a motor housing. [Means for solving the problem]

[0005] a motor housing disposed inside the air duct and accommodating the electric motor; a diffuser cone disposed inside the air duct and connected to the motor housing on the exhaust port side; a first vent provided at an end of the diffuser cone on the exhaust port side; and a second vent provided between the hub and the motor housing along the circumferential direction of the rotation shaft and having a width in the axial direction of the rotation shaft. The interior of the air duct is formed with an air flow path through which air from the intake port passes through the exterior of the hub, the exterior of the motor housing, and the exterior of the diffuser cone and flows toward the exhaust port, and a circulation path through which air flowing through the air flow path flows from the first air vent port into the interior of the diffuser cone, passes through the interior of the motor housing, and flows out from the second air vent port to the air flow path. When a peripheral end of the second air vent port on the intake port side is defined as a first end and a peripheral end of the second air vent port on the exhaust port side is defined as a second end, the outer diameter of the first end is larger than the outer diameter of the second end.

[0006] In the above configuration, air flowing along the outer surface of the hub in the airflow path separates from the outer surface of the hub at the first end and reattaches to the outer surface of the motor housing at a location closer to the exhaust port than the second end. Because the outer diameter of the first end is larger than the outer diameter of the second end, the distance between the point where the air separates (i.e., the separation point) and the point where the separated air reattaches (i.e., the reattachment point) increases. This increases the negative pressure that generates an airflow in the circulation path, thereby increasing the volume of cooling air for the electric motor. The above configuration allows the blower to properly cool the electric motor housed in the motor housing. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an overall perspective view of a blower 10 according to an embodiment, seen from above and rear right. [Figure 2] 1 is an exploded view of the internal structure of a blower body 13 of a blower 10 according to an embodiment, seen from the upper rear right side. [Figure 3] 1 is an exploded view showing a blower unit 50 and a control unit 80 provided in a first blower duct 210 of a blower 10 according to an embodiment, and components of the blower unit 50. FIG. [Figure 4] 1 is a cross-sectional view showing the internal structure of a first blower duct 210, a blower unit 50, and a control unit 80 in a blower 10 according to an embodiment. [Figure 5] 3 is a cross-sectional view showing components of a control unit 80 provided in the blower 10 according to the embodiment. FIG. [Figure 6] This figure shows the positional relationship between the electric motor 54, multiple switching elements 84, heat dissipation material 86, mounting portion 212, and exposure hole 216 when viewing the first air duct 210 of the blower 10 of the embodiment from the radially outer side along the vertical direction. [Figure 7] 10 is a cross-sectional view showing the positional relationship between an imaginary plane V extending along the inner surface of a first blower duct 210 and the lower surface of a controller casing 88 in a blower 10 according to the embodiment. FIG. [Figure 8]1 is a diagram showing an air flow path R1 formed inside a first air flow duct 210 and a circulation path R2 formed in a blower unit 50 in a blower 10 according to the embodiment. [Figure 9] 10 is a diagram showing a schematic diagram of a state in which, when air flows along the airflow path R1 in the blower 10 according to the embodiment, a negative pressure is generated that draws air from the circulation path R2 into the airflow path R1. FIG. [Figure 10] A cross-sectional view showing the first outer diameter φ1 of the exhaust port side end 620 of the hub 62, the second outer diameter φ2 of the intake port side end 560 of the motor housing 56, and the first inner diameter φ3 of the first air duct 210 in the blower 10 of the embodiment. [Figure 11] 1 is a graph showing the relationship between the ratio φ1 / φ2 of the first outer diameter φ1 to the second outer diameter φ2 and the respective rates of change of the cooling air volume and the working air volume when the fan 52 is rotated at a constant rotation speed in a blower 10 according to an embodiment. [Figure 12] 10 is a cross-sectional view showing a second inner diameter φ4 of a first ventilation port 58b in the blower 10 according to the embodiment. FIG. [Figure 13] 10 is a cross-sectional view showing the internal structure of a first blower duct 210, a blower unit 50, and a control unit 80 in a blower 10 according to a modified example. [Figure 14] FIG. 10 is a diagram schematically illustrating a state in which, when air flows along airflow path R1 in a blower 10 according to a modified example, a negative pressure is generated that draws air from circulation path R2 to airflow path R1. DETAILED DESCRIPTION OF THE INVENTION

[0008] Representative, non-limiting embodiments of the present invention are described in detail below with reference to the drawings. This detailed description is intended simply to provide those skilled in the art with details for implementing preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Additionally, the additional features and inventions disclosed can be used separately or in conjunction with other features and inventions to provide further improved blowers.

[0009] Furthermore, the combinations of features and steps disclosed in the following detailed description are not essential to practicing the invention in its broadest sense, but are described solely to specifically illustrate exemplary embodiments of the invention. Furthermore, the various features of the following exemplary embodiments and those described in the claims do not necessarily have to be combined in the exact embodiments described herein or in the exact order listed to provide additional and useful embodiments of the invention.

[0010] All features described in this specification and / or claims are intended to be disclosed individually and independently of one another as limitations to the specific features described in the original disclosure and claims, apart from the configuration of features described in the examples and / or claims. Furthermore, all numerical ranges and group or aggregate descriptions are intended to disclose intermediate configurations thereof as limitations to the specific features described in the original disclosure and claims.

[0011] In one or more embodiments, the first end is an end of the outer surface of the hub that faces the exhaust port, and the second end is an end of the outer surface of the motor housing that faces the intake port.

[0012] One way to increase the volume of cooling air for an electric motor is to install a separate component between the hub and the motor housing. In contrast, the above-described configuration increases the volume of cooling air for the electric motor without installing a separate component between the hub and the motor housing. This reduces the number of parts required for the blower.

[0013] In one or more embodiments, a vacuum augmenting member having an outer surface symmetrical about the rotation axis is provided between the hub and the motor housing, the first end being an end of the outer surface of the vacuum augmenting member on the exhaust port side, and the second end being an end of the outer surface of the motor housing on the intake port side.

[0014] According to the above configuration, by retrofitting a negative pressure increasing member between the hub and motor housing of a general blower, it is possible to increase the volume of cooling air for an electric motor. Therefore, it is possible to increase the volume of cooling air for an electric motor with a simple and inexpensive configuration. Note that the "general blower" here means a blower in which the hub and motor housing are flush with each other.

[0015] In one or more embodiments, the hub is fixed to the drive shaft, and the axis of rotation coincides with the axis of rotation of the drive shaft.

[0016] According to the above configuration, the blower can be made smaller than when a reducer or the like is provided between the hub and the drive shaft.

[0017] In one or more embodiments, the ratio of the outer diameter of the first end to the outer diameter of the second end may be in the range of 101%-116%.

[0018] If the ratio of the outer diameter of the first end to the outer diameter of the second end is too small, it may not be possible to sufficiently increase the negative pressure that generates an airflow in the circulation path. In other words, it may not be possible to sufficiently increase the volume of cooling air for the electric motor. On the other hand, if the ratio of the outer diameter of the first end to the outer diameter of the second end is too large, separation of the air flowing along the outer surface of the hub may disrupt the airflow generated in the airflow path by the operation of the fan. In other words, the disruption of the airflow may significantly reduce the volume of working air. With the above configuration, it is possible to sufficiently increase the volume of cooling air for the electric motor and suppress a decrease in the volume of working air. Note that, in this specification, "working air" means air discharged from the exhaust port along the airflow path.

[0019] In one or more embodiments, the ratio of the inner diameter of the air duct radially outward from the first end to the outer diameter at the second end may be in the range of 175%-195%.

[0020] If the ratio of the inner diameter of the air duct radially outward from the first end to the outer diameter of the second end is too small, the air flow path narrows as the outer diameter of the first end increases, which may significantly increase pressure loss in the air flow path.On the other hand, if the ratio of the inner diameter of the air duct radially outward from the first end to the outer diameter of the second end is too large, the air flow generated in the air flow path by driving the fan may be disturbed.With the above configuration, it is possible to suppress an increase in pressure loss in the air flow path and to suppress disturbance of the air flow in the air flow path.

[0021] In one or more embodiments, the first vent opens along the extension direction of the air duct and has a generally circular periphery. The ratio of the inner diameter of the first vent to the outer diameter of the second end may be in the range of 15%-50%.

[0022] If the ratio of the inner diameter of the first vent to the outer diameter of the second end is too small, the amount of air taken in by the first vent into the circulation path may be too small. On the other hand, if the ratio of the inner diameter of the first vent to the outer diameter of the second end is too large, the amount of air taken in by the first vent into the circulation path may be too large. With the above configuration, when the first vent is opened along the extension direction of the air duct, the amount of air taken in by the first vent into the circulation path can be made appropriate.

[0023] In one or more embodiments, the blower may further include a battery device for supplying power to the electric motor, and the electric motor may be configured to be driven by power supplied from the battery device.

[0024] When an electric motor is driven by power from an external power source, a power cord must be attached to the blower, which can lead to reduced operability. With the above configuration, there is no need to attach a power cord to the blower, which further improves user operability. Furthermore, the blower can be used even in places where an external power supply is unavailable, improving user convenience.

[0025] In one or more embodiments, the blower further includes a battery mounting portion including a connection terminal, and the battery device may be at least one battery pack removably mounted to the battery mounting portion.

[0026] For example, if the battery device is non-detachably attached to the blower, if the battery device runs out of power and operation is interrupted, operation with the blower cannot be immediately resumed until the battery device with the dead power is recharged. With the above configuration, even if operation is interrupted because the battery pack runs out of power, operation with the blower can be immediately resumed by replacing it with a pre-charged battery pack.

[0027] In one or more embodiments, the blower may further include a power cord for connecting to an external power source, and the electric motor may be configured to be driven by power supplied from the external power source.

[0028] When the electric motor is driven by power from a battery device included in the blower, the battery device must be charged in advance, which can be inconvenient for the user. However, with the above configuration, the blower can be used immediately by connecting the power cord to an external power source, eliminating the need for prior preparations such as charging the battery device. This reduces the inconvenience for the user.

[0029] (Example) As shown in Fig. 1, blower 10 includes a battery device 12, a blower main body 13, and a pair of shoulder straps 16. A user can wear blower 10 on their back by placing shoulder straps 16 over their shoulders. That is, blower 10 of this embodiment is a backpack-type blower. In the following description, the up-down, left-right, and front-to-back directions as seen from the user when the user is wearing blower 10 on their back are referred to as the up-down, left-right, and front-to-back directions of blower 10, respectively.

[0030] (Configuration of battery device 12) The battery device 12 houses a plurality of battery cells (not shown). The battery device 12 is equipped with a charging connector 24 and a discharging cable 26. The discharging cable 26 is connected to the blower body 13. The plurality of battery cells can be charged from an external power source (not shown) by connecting a charging cable (not shown) extending from the external power source to the charging connector 24. The plurality of battery cells can be discharged to the blower body 13 via the discharging cable 26.

[0031] (Configuration of blower body 13) The blower body 13 includes an outer housing 14, an air duct 20, and an operating grip 22. As shown in FIG. 2, the outer housing 14 includes an air intake port 30 on the left side. The air intake port 30 communicates between the inside and outside of the outer housing 14. The outer housing 14 also accommodates a portion of the air duct 20. The outer housing 14 holds the air duct 20 so that a first air duct 210 (described later) extends in the left-right direction.

[0032] (Configuration of air duct 20) The air duct 20 includes a first air duct 210 having a generally cylindrical shape extending in the left-right direction, a second air duct 220 having a generally cylindrical shape that bends from rear to front as it moves from left to right, a third air duct 230 having a bellows shape extending in the front-rear direction, and a fourth air duct 240 having a generally cylindrical shape extending in the front-rear direction. The third air duct 230 is configured to be extendable and retractable. The first air duct 210, the second air duct 220, the third air duct 230, and the fourth air duct 240 are connected in series. The left end of the first air duct 210 faces the air intake port 30 and is connected to the air intake port 30. The front end of the fourth air duct 240 is provided with an exhaust port 32. As described above, the air duct 20 is configured such that one end is connected to the air intake port 30 and the other end functions as the exhaust port 32. In this specification, with respect to the extension direction of the air duct 20, the side facing the intake port 30 may be referred to as the intake port side, and the side facing the exhaust port 32 may be referred to as the exhaust port side. For example, the left side of the first air duct 210 may be referred to as the intake port side, and the right side of the first air duct 210 may be referred to as the exhaust port side.

[0033] (Configuration of the operation grip 22) 1, the operation grip 22 is provided in a position on the fourth air duct 240 where it can be operated by a user by gripping it. The user can adjust the orientation of the fourth air duct 240 while gripping the operation grip 22, thereby adjusting the direction in which the exhaust port 32 is pointed. The operation grip 22 is also provided with a plurality of switches, such as triggers 28, which are operated by the user.

[0034] (Configuration of the blower unit 50) 3, the blower body 13 is disposed inside the air duct 20 and further includes an air blower unit 50 for blowing air from the air intake port 30 through the air duct 20 toward the air exhaust port 32. The air blower unit 50 includes a fan 52, an electric motor 54 that rotates and drives the fan 52, a motor housing 56 that accommodates the electric motor 54, and a diffuser cone 58 connected to the right end of the motor housing 56.

[0035] (Configuration of electric motor 54) The electric motor 54 includes a drive shaft 60 that can rotate around a rotation axis A1 that extends in the left-right direction. In this embodiment, the electric motor 54 is a brushless motor that includes a stator and a rotor (not shown). The drive shaft 60 is fixed to the rotor, and when power is supplied to the electric motor 54, the drive shaft 60 rotates around the rotation axis A1.

[0036] (Fan 52 configuration) As shown in FIG. 4, the fan 52 includes a hub 62 fixed to the drive shaft 60 from the intake port side, and a plurality of blades 64 provided on a first outer surface 62a of the hub 62. The hub 62 is rotatable around a rotation axis A1. The first outer surface 62a is formed in an axisymmetric shape centered on the rotation axis A1 of the drive shaft 60. An exhaust port-side end 620, which is the end of the first outer surface 62a on the exhaust port side, has a first outer diameter φ1 (see FIG. 10). In this embodiment, the fan 52 is an axial fan. For example, when the fan 52 rotates counterclockwise when the blower unit 50 is viewed from the intake port side, the fan 52 generates an airflow along the rotation axis A1 from the intake port side to the exhaust port side (i.e., from left to right in FIG. 4).

[0037] (Configuration of motor housing 56) As shown in FIG. 3 , the motor housing 56 includes a cylindrical portion 66 extending along the rotation axis A1, a bottom portion 68 provided on the exhaust port side of the electric motor 54, and a lid portion 70 provided on the intake port side of the electric motor 54. The motor housing 56 is supported inside the first air duct 210 by multiple support members 72 formed on the cylindrical portion 66. The cylindrical portion 66, the bottom portion 68, the multiple support members 72, and the first air duct 210 are seamlessly formed as a single unit. The lid portion 70 is fixed to the cylindrical portion 66 with screws (not shown). Therefore, the electric motor 54 is housed in the motor housing 56 by inserting the electric motor 54 into the cylindrical portion 66 and then fixing the lid portion 70 to the cylindrical portion 66. In this embodiment, the cylindrical portion 66, the bottom portion 68, the lid portion 70, the multiple support members 72, and the first air duct 210 are made of a resin such as nylon.

[0038] As shown in FIG. 4, the cylindrical portion 66 has an outer surface 66a formed in a substantially cylindrical shape centered on the rotational axis A1 of the drive shaft 60. The lid portion 70 has an outer surface 70a formed in an axisymmetric shape centered on the rotational axis A1. When the lid portion 70 is fixed to the cylindrical portion 66, the outer surface 66a and the outer surface 70a are connected substantially smoothly along the direction of the rotational axis A1. For this reason, in this specification, the outer surface 66a and the outer surface 70a may be collectively referred to as the "second outer surface 56a." Furthermore, an intake port-side end 560, which is the end of the second outer surface 56a on the intake port side, has a second outer diameter φ2 (see FIG. 10). Here, a second vent 62b is provided between the exhaust port-side end 620 of the hub 62 and the intake port-side end 560 of the motor housing 56. The second ventilation opening 62b is provided along the circumferential direction of the rotation axis A1 between the exhaust port side end 620 and the intake port side end 560. The second ventilation opening 62b has a width in the axial direction of the rotation axis A1. As described above, the second ventilation opening 62b is formed with the exhaust port side end 620 and the intake port side end 560 as its circumferential ends. The second ventilation opening 62b also communicates with the interior of the hub 62 and a ventilation path R1 (see FIG. 8), which will be described later.

[0039] The bottom portion 68 has a first communication hole 68b arranged between the electric motor 54 and the diffuser cone 58 in the direction of the rotation axis A1. The first communication hole 68b connects the interior of the motor housing 56 with the interior of the diffuser cone 58. In this embodiment, a plurality of first communication holes 68b are provided in the circumferential direction at predetermined angular intervals (for example, 60° intervals). The lid portion 70 has a second communication hole 70b arranged between the hub 62 and the electric motor 54 in the direction of the rotation axis A1. The second communication hole 70b connects the interior of the hub 62 with the interior of the motor housing 56. In this embodiment, a plurality of second communication holes 70b are provided in the circumferential direction at predetermined angular intervals (for example, 40° intervals).

[0040] (Diffuser cone 58 configuration) The diffuser cone 58 is connected to the exhaust port side of the cylindrical portion 66 of the motor housing 56 and extends along the rotation axis A1. A portion of the diffuser cone 58 extends toward the exhaust port side beyond the right end of the first air duct 210. That is, the diffuser cone 58 extends across the first air duct 210 and the second air duct 220. The diffuser cone 58 also has a third outer surface 58a formed in an axisymmetric shape centered on the rotation axis A1. The third outer surface 58a smoothly connects to the second outer surface 56a along the rotation axis A1. The diameter of the third outer surface 58a decreases from the intake port side toward the exhaust port side along the rotation axis A1. The diffuser cone 58 has a substantially circular first vent hole 58b whose periphery is the end of the third outer surface 58a on the exhaust port side. The first vent hole 58b opens along the rotation axis A1. First ventilation port 58b has a second inner diameter φ4 (see FIG. 12). First ventilation port 58b communicates the inside of diffuser cone 58 with air flow path R1 (see FIG. 8), which will be described later.

[0041] (Configuration of control unit 80) As shown in FIG. 3 , the blower body 13 further includes a control unit 80 for controlling the blower unit 50. The control unit 80 is mounted on a mounting portion 212 provided on an upper portion of the first air duct 210. The control unit 80 is fixed to the first air duct 210 by the mounting portion 212 and a cover member 214 screwed to the mounting portion 212. The control unit 80 is electrically connected to the battery device 12 (see FIG. 1 ), the trigger 28 (see FIG. 1 ), and the electric motor 54. When the user operates the trigger 28, the control unit 80 adjusts the power supplied from the battery device 12 and supplies it to the electric motor 54, thereby driving the electric motor 54. In this embodiment, the control unit 80 is configured to control the driving of the electric motor 54 so that the fan 52 generates an airflow from the intake port side to the exhaust port side along the rotation axis A1.

[0042] As shown in FIG. 5 , the control unit 80 includes a control board 82, multiple switching elements 84 provided on the upper surface of the control board 82, a heat dissipation material 86 provided in close contact with the lower surface of the control board 82, a controller casing 88 that houses the control board 82, the multiple switching elements 84, and the heat dissipation material 86, and a potting resin 90 that seals the control board 82, the multiple switching elements 84, and the heat dissipation material 86. The heat dissipation material 86 is also provided in close contact with the upper surface of the controller casing 88. The controller casing 88 includes multiple fins 92 on a portion of its lower surface. The multiple switching elements 84 are disposed above the portion of the controller casing 88 where the multiple fins 92 are provided. In this embodiment, the heat dissipation material 86 is made of a sheet-like aluminum alloy. In this embodiment, the controller casing 88 is made of a metal such as aluminum. In this embodiment, the multiple switching elements 84 are field-effect transistors (FETs) that form an inverter circuit. Therefore, the control unit 80 can convert DC power supplied from the battery device 12 (see FIG. 1) into three-phase AC power and supply it to the electric motor .

[0043] As shown in Fig. 4, an exposure hole 216 that connects the inside and outside of the first air duct 210 in the radial direction of the first air duct 210 is provided in the upper part of the first air duct 210. The exposure hole 216 is provided closer to the exhaust port side than the fan 52. The control unit 80 is attached to the first air duct 210 so that a part of the controller casing 88 completely blocks the exposure hole 216 from the radial outside of the first air duct 210. When the control unit 80 is attached to the first air duct 210, a part of the underside of the controller casing 88 where a plurality of fins 92 are provided (see Fig. 5) is exposed to an air flow path R1 (see Fig. 8) described later.

[0044] As shown in Fig. 6, in this embodiment, when the exposure hole 216 is viewed from the radially outer side of the first air duct 210 in the up-down direction, a part of the electric motor 54, the multiple switching elements 84, and the heat dissipation material 86 are arranged so as to overlap with the exposure hole 216. Note that, for ease of explanation, components other than the electric motor 54, the multiple switching elements 84, the heat dissipation material 86, the mounting portion 212 (first air duct 210), and the exposure hole 216 are omitted from Fig. 6.

[0045] 7, the lower surface of the controller casing 88 has a generally flat shape that extends in the front-rear and left-right directions. The lower surface of the controller casing 88 is located radially outward of the first air duct 210 from an imaginary plane V that extends along the inner surface of the first air duct 210 at the portion where the exposure hole 216 is provided. Note that the shortest distance d1 between the lower surface of the controller casing 88 and the imaginary plane V in the radial direction of the first air duct 210 is 2 mm. The longest distance d2 between the lower surface of the controller casing 88 and the imaginary plane V in the radial direction of the first air duct 210 is 12 mm.

[0046] (Air flow path R1) As shown in Fig. 8, an air flow path R1 is formed inside the air duct 20, extending from the left end of the first air duct 210 to the second air duct 220, passing through the outside of the hub 62, the outside of the motor housing 56, and the outside of the diffuser cone 58 in this order. Although not shown, the air flow path R1 reaches the second air duct 220, then passes through the third air duct 230 (see Fig. 2) and the fourth air duct 240 (see Fig. 2), and then reaches the exhaust port 32 (see Fig. 2). In the blower 10 of this embodiment, when the fan 52 generates an air flow from the intake port side to the exhaust port side, the air from the intake port 30 flows through the air flow path R1 toward the exhaust port 32, passing through the outside of the hub 62, the outside of the motor housing 56, and the outside of the diffuser cone 58.

[0047] As described above, the multiple fins 92 (see FIG. 5) of the controller casing 88 that cover the exposure hole 216 are exposed to the airflow path R1. Therefore, the air flowing along the airflow path R1 guides the heat released from the multiple fins 92 exposed to the airflow path R1 to the exhaust port 32. That is, the air flowing along the airflow path R1 is used as cooling air that suppresses a temperature rise in the control unit 80. With the blower 10 of this embodiment, the entire amount of air used as cooling air is discharged from the exhaust port 32. Therefore, with the blower 10 of this embodiment, it is possible to cool the control unit 80 without reducing the volume of working air.

[0048] (Circulation route R2) In the blower unit 50, a circulation path R2 is formed, which runs from the airflow path R1 through the first vent port 58b, the interior of the diffuser cone 58, the first communication hole 68b, the interior of the motor housing 56, the second communication hole 70b, the interior of the hub 62, and the second vent port 62b in this order, and then returns to the airflow path R1. In the circulation path R2, the air flowing through the airflow path R1 flows into the interior of the diffuser cone 58 from the first vent port 58b, passes through the interior of the motor housing 56, and flows out from the second vent port 62b to the airflow path R1.

[0049] As shown in FIG. 9, when air flows along the airflow path R1, the air flowing along the first outer surface 62a separates from the first outer surface 62a at the exhaust port-side end 620, generating a negative pressure in the second air vent 62b that draws air from the circulation path R2 to the airflow path R1. At this time, as shown in FIG. 8, a negative pressure is generated in the first air vent 58b that draws air from the airflow path R1 to the circulation path R2. Thus, when air flows along the airflow path R1, a portion of the air flowing along the airflow path R1 also flows along the circulation path R2. The air flowing along the circulation path R2 guides heat generated in the electric motor 54 housed inside the motor housing 56 to the airflow path R1. In other words, the air flowing along the circulation path R2 is used as cooling air to suppress a rise in temperature of the electric motor 54.

[0050] (Negative pressure increasing mechanism near the second ventilation port 62b) As shown in FIG. 10 , in this embodiment, the first outer diameter φ1 of the exhaust port-side end 620 of the hub 62 is larger than the second outer diameter φ2 of the intake port-side end 560 of the motor housing 56. As described above, the hub 62 and the motor housing 56 each have an axisymmetric shape centered on the rotational axis A1 of the drive shaft 60, and therefore the intake port-side end 560 is offset radially inward from the rotational axis A1 relative to the exhaust port-side end 620. This increases the distance from the point at which air flowing along the first outer surface 62a separates from the first outer surface 62a (i.e., the separation point) to the point at which the separated air reattaches on the second outer surface 56a (i.e., the reattachment point). This increases the negative pressure that generates an airflow in the circulation path R2. Therefore, the blower 10 of this embodiment can increase the volume of cooling air used to cool the electric motor 54.

[0051] (ratio of first outer diameter φ1 to second outer diameter φ2 φ1 / φ2) As shown in FIG. 11 , the flow rate of the cooling air for cooling the electric motor 54 (cooling air flow rate) and the flow rate of the working air vary depending on the ratio φ1 / φ2 of the first outer diameter φ1 to the second outer diameter φ2. The cooling air flow rate monotonically increases when the ratio φ1 / φ2 of the first outer diameter φ1 to the second outer diameter φ2 increases from 100% to 115%, but monotonically decreases when the ratio φ1 / φ2 of the first outer diameter φ1 to the second outer diameter φ2 increases beyond 116%. The flow rate of the working air monotonically decreases as the ratio φ1 / φ2 of the first outer diameter φ1 to the second outer diameter φ2 increases. Therefore, as long as the ratio φ1 / φ2 of the first outer diameter φ1 to the second outer diameter φ2 is within the range of 101% to 116%, the cooling air flow rate can be effectively increased while suppressing a decrease in the flow rate of the working air. In FIG. 11, the rate of change in the cooling airflow and the working airflow when φ1 / φ2 is changed is shown assuming that the rate of change in the airflow when φ1 / φ2 is 100% is 100%.

[0052] In particular, when the ratio φ1 / φ2 of the first outer diameter φ1 to the second outer diameter φ2 increases from 100% to 103%, the gradient of the rate of change (increase) of the cooling airflow is relatively large. Furthermore, the gradient of the rate of change (decrease) of the working airflow is substantially constant regardless of the ratio φ1 / φ2 of the first outer diameter φ1 to the second outer diameter φ2. Therefore, if the ratio φ1 / φ2 of the first outer diameter φ1 to the second outer diameter φ2 is 103%, the cooling airflow can be more effectively increased while further suppressing the decrease in the working airflow. Therefore, in the blower 10 of this embodiment, the ratio φ1 / φ2 of the first outer diameter φ1 to the second outer diameter φ2 is 103%.

[0053] (ratio of first inner diameter φ3 to second outer diameter φ2: φ3 / φ2) As shown in FIG. 10 , the first air duct 210 has a first inner diameter φ3 at the radially outer side of the outlet-side end 620. If the ratio φ3 / φ2 of the first inner diameter φ3 to the second outer diameter φ2 is too small, the air flow path R1 may be narrowed as the first outer diameter φ1 is increased, which may result in a significant increase in pressure loss in the air flow path R1. On the other hand, if the ratio φ3 / φ2 of the first inner diameter φ3 to the second outer diameter φ2 is too large, the air flow generated in the air flow path R1 by driving the fan 52 may be disturbed. In this embodiment, the ratio φ3 / φ2 of the first inner diameter φ3 to the second outer diameter φ2 is 187%. This prevents an increase in pressure loss in the air flow path R1 and also prevents air flow disturbance in the air flow path R1.

[0054] (ratio of second inner diameter φ4 to second outer diameter φ2 φ4 / φ2) Furthermore, if the ratio φ4 / φ2 of the second inner diameter φ4 (see FIG. 12) of the first ventilation port 58b to the second outer diameter φ2 is too small, the amount of air taken in by the first ventilation port 58b into the circulation path R2 may be too small. On the other hand, if the ratio φ4 / φ2 of the second inner diameter φ4 to the second outer diameter φ2 is too large, the amount of air taken in by the first ventilation port 58b into the circulation path R2 may be too large. In this embodiment, the ratio φ4 / φ2 of the second inner diameter φ4 to the second outer diameter φ2 is 33%. Therefore, the amount of air taken in by the first ventilation port 58b into the circulation path R2 can be made appropriate.

[0055] (Variation) In the above embodiment, the blower 10 is a backpack-type blower. In another embodiment, the blower 10 may be a blower other than a backpack-type blower. For example, the blower 10 may be a handheld blower.

[0056] In the above embodiment, the blower 10 includes the battery device 12 connected to the blower body 13 via the discharge cable 26, and power is supplied from the battery device 12 to the electric motor 54. In another embodiment, instead of the battery device 12, the blower 10 may include at least one battery pack (another example of a battery device) that is provided in the blower body 13 and detachably attached to a battery attachment portion (not shown) that has connection terminals. When at least one battery pack is attached to the battery attachment portion, power may be supplied from the at least one battery pack to the electric motor 54. In yet another embodiment, instead of the battery device 12, the blower 10 may include a power cord for connecting the blower body 13 to an external power source, and power may be supplied to the electric motor 54 from the external power source via the power cord.

[0057] In the above embodiment, the air duct 20 is described as including the first air duct 210, the second air duct 220, the third air duct 230, and the fourth air duct 240. In another embodiment, the air duct 20 may not include at least one of the second air duct 220, the third air duct 230, and the fourth air duct 240.

[0058] In the above embodiment, the electric motor 54 is a brushless motor. In another embodiment, the electric motor 54 may be a motor other than a brushless motor. For example, the electric motor 54 may be a motor with brushes.

[0059] In the above embodiment, a configuration has been described in which the hub 62 is fixed to the drive shaft 60. In another embodiment, a reducer (not shown) may be provided between the hub 62 and the drive shaft 60. In this case, the hub 62 may be fixed to an output shaft different from the drive shaft 60, and the output shaft may be connected to the drive shaft 60 via the reducer. In other words, the hub 62 may be provided to be rotatable around a rotation axis different from the rotation axis A1 of the drive shaft 60.

[0060] In the above embodiment, the cylindrical portion 66, the bottom portion 68, the plurality of support members 72, and the first air duct 210 are seamlessly formed as a single unit. In another embodiment, at least one of the cylindrical portion 66, the bottom portion 68, the plurality of support members 72, and the first air duct 210 may be formed as a separate body.

[0061] In the above embodiment, a configuration has been described in which resin such as nylon is used for the cylindrical portion 66, the bottom portion 68, the lid portion 70, the plurality of support members 72, and the first air duct 210. In another embodiment, a material other than resin may be used for at least one of the cylindrical portion 66, the bottom portion 68, the lid portion 70, the plurality of support members 72, and the first air duct 210. For example, aluminum or the like may be used for at least one of the cylindrical portion 66, the bottom portion 68, the lid portion 70, the plurality of support members 72, and the first air duct 210.

[0062] In the above embodiment, an aluminum alloy is used for the heat dissipation material 86. In another embodiment, a material other than an aluminum alloy may be used for the heat dissipation material 86. For example, silicone rubber or the like may be used for the heat dissipation material 86.

[0063] In the above embodiment, a configuration has been described in which a metal such as aluminum is used for the controller casing 88. In another embodiment, a material other than metal may be used for the controller casing 88. For example, the controller casing 88 may be made of nylon or the like.

[0064] In the above embodiment, a configuration has been described in which the exposure hole 216 is provided downstream of the fan 52 (on the exhaust port side), and the controller casing 88 is exposed to the airflow path R1 downstream of the fan 52. In another embodiment, the exposure hole 216 may be provided upstream of the fan 52 (on the intake port side), and the controller casing 88 may be exposed to the airflow path R1 upstream of the fan 52.

[0065] In the above embodiment, a configuration has been described in which the electric motor 54 and the exposure hole 216 partially overlap when the exposure hole 216 is viewed from the radially outside of the first air duct 210. In another embodiment, the electric motor 54 and the exposure hole 216 may not overlap when the exposure hole 216 is viewed from the radially outside of the first air duct 210. In this case, the exposure hole 216 may be located closer to the exhaust port than the electric motor 54, or closer to the intake port than the electric motor 54.

[0066] In the above embodiment, a configuration has been described in which the bottom surface of the controller casing 88 has a substantially flat shape. In another embodiment, the bottom surface of the controller casing 88 does not have to have a substantially flat shape. For example, the bottom surface of the controller casing 88 may have a shape that follows the imaginary plane V.

[0067] In the above embodiment, a configuration has been described in which the lower surface of the controller casing 88 is disposed radially outward from the first air duct 210 relative to the imaginary plane V that extends along the inner surface of the first air duct 210 at the portion where the exposure holes 216 are provided. In another embodiment, the lower surface of the controller casing 88 does not have to be disposed radially outward from the first air duct 210 relative to the imaginary plane V that extends along the inner surface of the first air duct 210 at the portion where the exposure holes 216 are provided. For example, the lower surface of the controller casing 88 may be disposed radially inward from the first air duct 210 relative to the imaginary plane V that extends along the inner surface of the first air duct 210 at the portion where the exposure holes 216 are provided.

[0068] In the above embodiment, a configuration has been described in which the mounting portion 212 and the exposure hole 216 are provided on the upper part of the first air duct 210, and the control unit 80 is attached to the upper part of the first air duct 210. In another embodiment, the mounting portion 212 and the exposure hole 216 may be provided at a position other than the upper part of the first air duct 210, and the control unit 80 may be attached at a position other than the upper part of the first air duct 210. For example, the mounting portion 212 and the exposure hole 216 may be provided at a lower part or the like of the first air duct 210, and the control unit 80 may be attached at a lower part or the like of the first air duct 210.

[0069] In the above embodiment, the multiple switching elements 84 are FETs. In another embodiment, the multiple switching elements 84 may be switching elements other than FETs. For example, the multiple switching elements 84 may be IGBTs (insulated gate bipolar transistors) or the like.

[0070] In the above embodiment, the ratio φ1 / φ2 of the first outer diameter φ1 to the second outer diameter φ2 is 103%. In another embodiment, the ratio φ1 / φ2 of the first outer diameter φ1 to the second outer diameter φ2 may be changed as appropriate within the range of 101% to 116%.

[0071] In the above embodiment, the ratio φ3 / φ2 of the first inner diameter φ3 to the second outer diameter φ2 is 187%. In another embodiment, the ratio φ3 / φ2 of the first inner diameter φ3 to the second outer diameter φ2 may be changed as appropriate within the range of 175% to 195%.

[0072] In the above embodiment, the ratio φ4 / φ2 of the second inner diameter φ4 to the second outer diameter φ2 is 33%. In another embodiment, the ratio φ4 / φ2 of the second inner diameter φ4 to the second outer diameter φ2 may be changed as appropriate within the range of 15% to 50%.

[0073] 13 , in another embodiment, the blower 10 may include a second air duct 320 instead of the second air duct 220, and may include a diffuser cone 158 instead of the diffuser cone 58. The second air duct 320 has a shape that curves from top to bottom as it moves from left to right. The diffuser cone 158 has a shape that curves from top to bottom as it moves from left to right, following the curved shape of the second air duct 320. In this case, the first air opening 58b opens along the extension direction of the second air duct 320.

[0074] As shown in FIG. 14 , in another embodiment, a disk-shaped plate member 100 may be disposed between the hub 62 and the motor housing 56. The plate member 100 may have an outer surface 100a that is axially symmetrical about the rotation axis A1. The plate member 100 may be fixed to the drive shaft 60 (see FIG. 4 ) separately from the hub 62. Furthermore, instead of forming the second vent 62b with the exhaust port-side end 620 of the hub 62 and the intake port-side end 560 of the motor housing 56 as its peripheral ends, the second vent 62b may be formed with the exhaust port-side end 102 and the intake port-side end 560, which are the exhaust port-side ends of the outer surface 100a of the plate member 100. Although not shown, the outer diameter of the exhaust port-side end 102 may be larger than the outer diameter φ2 of the intake port-side end 560. In this case, the outer diameter φ1 of the exhaust port-side end 620 may be equal to or smaller than the outer diameter φ2 of the intake port-side end 560. In this case, the plate member 100 increases the negative pressure that generates an air flow in the circulation path R2. That is, the plate member 100 increases the amount of cooling air for cooling the electric motor .

[0075] (Correspondence) As described above, in one or more embodiments, the blower 10 includes the air intake 30, the exhaust port 32, the air duct 20 provided between the air intake 30 and the exhaust port 32, the fan 52 (an example of an axial flow fan) that is disposed inside the air duct 20 and includes the hub 62 rotatably provided around a predetermined rotation axis A1 along the extension direction of the air duct 20 (specifically, the first air duct 210), and the plurality of blades 64 provided on the first outer surface 62a of the hub 62, the drive shaft 60 that is disposed inside the air duct 20 and connected to the fan 52, and the drive shaft 60 that is disposed inside the air duct 20 and is located closer to the exhaust port than the fan 52. the hub 62 and the motor housing 56 are provided with an electric motor 54 that rotates and drives the drive shaft 60, a motor housing 56 that is disposed inside the air duct 20 and that houses the electric motor 54, a diffuser cone 58 (or a diffuser cone 158) that is disposed inside the air duct 20 and connected to the exhaust port side of the motor housing 56, a first ventilation port 58b provided at the end of the diffuser cone 58 (or a diffuser cone 158) on the exhaust port side, and a second ventilation port 62b that is provided between the hub 62 and the motor housing 56 along the circumferential direction of the rotation axis A1 and has a width in the axial direction of the rotation axis A1. Inside the air flow duct 20, there is formed an air flow path R1 along which air from the air intake 30 flows toward the air exhaust 32 via the outside of the hub 62, the outside of the motor housing 56, and the outside of the diffuser cone 58 (or the diffuser cone 158), and a circulation path R2 along which the air flowing through the air flow path R1 flows from the first air vent 58b into the inside of the diffuser cone 58 (or the diffuser cone 158), passes through the inside of the motor housing 56, and flows out from the second air vent 62b to the air flow path R1. When the peripheral end of the second air vent 62b on the air intake side is defined as a first end and the peripheral end of the second air vent 62b on the air exhaust side is defined as a first end, the first end is the air exhaust side end 620 (or the air exhaust side end 102), and the second end is the air intake side end 560. The first outer diameter φ1 of the outlet port side end 620 (or the outer diameter of the outlet port side end 102) is larger than the second outer diameter φ2 of the inlet port side end 560.

[0076] In the above configuration, the air flowing along the first outer surface 62a of the hub 62, part of the air flowing through the airflow path R1, separates from the first outer surface 62a of the hub 62 at the exhaust port-side end 620 (or the exhaust port-side end 102) and reattaches to the second outer surface 56a of the motor housing 56, closer to the exhaust port than the intake port-side end 560. According to the above configuration, the first outer diameter φ1 of the exhaust port-side end 620 (or the outer diameter of the exhaust port-side end 102) is larger than the second outer diameter φ2 of the intake port-side end 560. This increases the distance from the point where the air separates (i.e., the separation point) to the point where the separated air reattaches (i.e., the reattachment point). This increases the negative pressure that generates an airflow in the circulation path R2, thereby increasing the volume of cooling air for the electric motor 54. According to the above configuration, the blower 10 can appropriately cool the electric motor 54 housed in the motor housing 56.

[0077] In one or more embodiments, the first end is the exhaust end 620 (an example of an end on the exhaust side of the hub's exterior surface), and the second end is the intake end 560 (an example of an end on the intake side of the motor housing's exterior surface).

[0078] As a means for increasing the volume of cooling air for the electric motor 54, for example, another member may be provided between the hub 62 and the motor housing 56. In contrast, with the above-described configuration, the volume of cooling air for the electric motor 54 can be increased without providing another member between the hub 62 and the motor housing 56. This allows the number of parts in the blower 10 to be reduced.

[0079] In one or more embodiments, a plate member 100 (an example of a negative pressure-increasing member) having an outer surface 100a shaped axially symmetrically about the rotation axis A1 is provided between the hub 62 and the motor housing 56. The first end is an outlet port-side end 102 (an example of an end of the outer surface of the plate member on the outlet port side). The second end is an intake port-side end 560 (an example of an end of the outer surface of the motor housing on the intake port side).

[0080] According to the above-described configuration, the volume of cooling air for the electric motor 54 can be increased by retrofitting the plate member 100 between the hub 62 and the motor housing 56 of a typical blower 10. Therefore, the volume of cooling air for the electric motor 54 can be increased with a simple and inexpensive configuration.

[0081] In one or more embodiments, the hub 62 is fixed to the drive shaft 60. The rotation axis A1 coincides with the rotation axis A1 of the drive shaft 60.

[0082] According to the above configuration, the blower 10 can be made smaller in size than when a reducer or the like is provided between the hub 62 and the drive shaft 60.

[0083] In one or more embodiments, the ratio φ1 / φ2 of the first outer diameter φ1 of the outlet end 620 to the second outer diameter φ2 of the inlet end 560 is in the range of 101%-116%.

[0084] If the ratio φ1 / φ2 of the first outer diameter φ1 of the exhaust port-side end 620 to the second outer diameter φ2 of the intake port-side end 560 is too small, the negative pressure required to generate an airflow in the circulation path R2 may not be sufficiently increased. In other words, the volume of cooling air for the electric motor 54 may not be sufficiently increased. On the other hand, if the ratio φ1 / φ2 of the first outer diameter φ1 of the exhaust port-side end 620 to the second outer diameter φ2 of the intake port-side end 560 is too large, separation of air flowing along the first outer surface 62a may disrupt the airflow generated in the airflow path R1 by the operation of the fan 52. In other words, the volume of working air may be significantly reduced due to the disruption of the airflow. The above configuration can sufficiently increase the volume of cooling air for the electric motor 54 while suppressing a reduction in the volume of working air.

[0085] In one or more embodiments, the ratio φ3 / φ2 of the first inner diameter φ3 of the first air duct 210 radially outside the exhaust port end 620 to the second outer diameter φ2 of the intake port end 560 is within the range of 175%-195%.

[0086] If the ratio φ3 / φ2 of the first inner diameter φ3 of the first blower duct 210 at the radially outer side of the exhaust port-side end 620 to the second outer diameter φ2 of the intake port-side end 560 is too small, the airflow path R1 may be narrowed as the first outer diameter φ1 of the exhaust port-side end 620 is increased, which may significantly increase pressure loss in the airflow path R1. On the other hand, if the ratio φ3 / φ2 of the first inner diameter φ3 of the first blower duct 210 at the radially outer side of the exhaust port-side end 620 to the second outer diameter φ2 of the intake port-side end 560 is too large, the airflow generated in the airflow path R1 by driving the fan 52 may be disturbed. With the above configuration, it is possible to suppress an increase in pressure loss in the airflow path R1 and to suppress disturbance of the airflow in the airflow path R1.

[0087] In one or more embodiments, the first ventilation opening 58b opens along the extension direction of the first air duct 210 (or along the extension direction of the second air duct 320) and has a substantially circular periphery. The ratio φ4 / φ2 of the second inner diameter φ4 of the first ventilation opening 58b to the second outer diameter φ2 of the intake port side end 560 is within the range of 15%-50%.

[0088] If the ratio φ4 / φ2 of the second inner diameter φ4 of the first vent 58b to the second outer diameter φ2 of the air inlet-side end 560 is too small, the amount of air taken in by the first vent 58b into the circulation path R2 may be too small. On the other hand, if the ratio φ4 / φ2 of the second inner diameter φ4 of the first vent 58b to the second outer diameter φ2 of the air inlet-side end 560 is too large, the amount of air taken in by the first vent 58b into the circulation path R2 may be too large. According to the above configuration, when the first vent 58b is opened along the extension direction of the first air duct 210 (or the extension direction of the second air duct 320), the amount of air taken in by the first vent 58b into the circulation path R2 can be made appropriate.

[0089] In one or more embodiments, the blower 10 further includes a battery device 12 (or at least one battery pack) (an example of a battery device) for supplying power to the electric motor 54. The electric motor 54 is configured to be driven by power supplied from the battery device 12 (or at least one battery pack).

[0090] When the electric motor 54 is driven by power from an external power source, a power cord must be attached to the blower 10, which can lead to reduced operability. However, with the above configuration, there is no need to attach a power cord to the blower 10, which further improves user operability. Furthermore, the blower 10 can be used even in places where an external power supply is not available, which improves user convenience.

[0091] In one or more embodiments, the blower 10 further includes a battery mounting portion including connection terminals, and the battery device is at least one battery pack removably mounted in the battery mounting portion.

[0092] For example, if the battery device is non-detachably attached to the blower 10, when the battery device runs out of power and operation is interrupted, operation using the blower 10 cannot be immediately resumed until the battery device is recharged. With the above configuration, even if operation is interrupted when the battery pack runs out of power, operation using the blower 10 can be immediately resumed by replacing it with a pre-charged battery pack.

[0093] In one or more embodiments, the blower 10 further includes a power cord for connecting to an external power source, and the electric motor 54 is configured to be powered by power provided by the external power source.

[0094] When the electric motor 54 is driven by power from a battery device included in the blower 10, the battery device must be charged in advance, which can be inconvenient for the user. However, with the above configuration, the blower 10 can be used immediately by connecting the power cord to an external power source, eliminating the need for prior preparations such as charging the battery device. This reduces the inconvenience for the user. [Explanation of symbols]

[0095] 10: Blower 12: Battery device 13: Blower body 14: Outer housing 16: Shoulder belt 20: Air pipe 22: Operation grip 24: Charging connector 26: Discharge cable 28: Trigger 30: Air intake 32: Exhaust port 50: Blower unit 52: Fan 54: Electric motor 56: Motor housing 56a: 2nd outer surface 58, 158: Diffuser cone 58a: Third outer surface 58b: First ventilation opening 60: Drive shaft 62: Hub 62a: 1st outer surface 62b: Second ventilation port 64: Multiple Blades 66: Cylindrical part 66a: Outer surface 68: Bottom 68b: 1st communication hole 70: Lid 70a: Outer surface 70b: 2nd communication hole 72: Multiple support members 80: Control unit 82: Control board 84: Multiple switching elements 86: Heat dissipation material 88: Controller casing 90: Potting resin 92: Multiple Fins 100: Plate member 100a: outer surface of plate member 102: Exhaust port side end of plate member 210: 1st air pipe 212: Placement section 214: Cover member 216: Exposure hole 220, 320: 2nd air pipe 230: 3rd blow pipe 240: 4th blow pipe 560: Intake port end of motor housing 620: Hub end on the exhaust port side A1: Rotation axis R1: Air flow path R2: Circulation route V: Virtual plane

Claims

1. An intake port, An exhaust port, an air duct provided between the intake port and the exhaust port; an axial flow fan disposed inside the air duct and including a hub rotatable about a predetermined rotation axis along an extension direction of the air duct, and a plurality of blades provided on an outer surface of the hub; a drive shaft disposed inside the air duct and connected to the axial fan; an electric motor that is disposed inside the air duct and closer to the exhaust port than the axial flow fan, and that rotates and drives the drive shaft; a motor housing disposed inside the air duct and accommodating the electric motor; a diffuser cone disposed inside the air duct and connected to the exhaust port side of the motor housing; a first vent provided at an end of the diffuser cone on the exhaust port side; a second vent hole provided between the hub and the motor housing along the circumferential direction of the rotary shaft and having a width in the axial direction of the rotary shaft, Inside the air duct, an air flow path through which air from the intake port flows toward the exhaust port via an outside of the hub, an outside of the motor housing, and an outside of the diffuser cone; a circulation path is formed in which air flowing through the air blowing path flows into the interior of the diffuser cone from the first air vent, passes through the interior of the motor housing, and flows out to the air blowing path from the second air vent, a peripheral end portion of the second vent port on the intake port side is defined as a first end portion, and a peripheral end portion of the second vent port on the exhaust port side is defined as a second end portion, the outer diameter of the first end portion is larger than the outer diameter of the second end portion, a negative pressure increasing member having an outer surface symmetrical about the rotation axis is provided between the hub and the motor housing; the first end is an end of the outer surface of the negative pressure increasing member on the exhaust port side, The second end is an end of the outer surface of the motor housing on the intake port side.

2. The hub is fixed to the drive shaft, 2. The blower of claim 1, wherein the axis of rotation is coincident with the axis of rotation of the drive shaft.

3. 2. The blower of claim 1, wherein a ratio of the outer diameter of the first end to the outer diameter of the second end is within the range of 101%-116%.

4. 4. The blower of claim 3, wherein a ratio of an inner diameter of the air duct radially outward of the first end to the outer diameter of the second end is within a range of 175%-195%.

5. The first ventilation port is open along the extension direction of the air duct and has a substantially circular peripheral edge portion, 2. The blower of claim 1, wherein a ratio of an inner diameter of the first vent to the outer diameter of the second end is within the range of 15%-50%.

6. The vehicle further includes a battery device for supplying power to the electric motor; The blower according to claim 1 , wherein the electric motor is configured to be driven by power supplied from the battery device.

7. Further comprising a battery mounting portion including a connection terminal; 7. The blower of claim 6, wherein the battery device is at least one battery pack removably mounted to the battery mounting portion.

8. It also includes a power cord for connecting to an external power source; The blower of claim 1 , wherein the electric motor is configured to be driven by power supplied from the external power source.

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