Outdoor unit and refrigeration cycle device

Abstract

An outdoor unit according to the present invention comprises: a box-shaped housing in which an intake port and a blowout port are formed; and an axial flow fan that is disposed inside the housing and rotates to form airflow. The housing has a cylindrical bell mouth that constitutes the blowout port and surrounds the outer circumference of the axial flow fan. The axial flow fan is provided with: a hub that is rotationally driven and forms a rotating shaft; a plurality of blades that are formed around the hub and extend radially outward from the hub; and a cylindrical ring part that is formed in an annular shape when viewed in the axial direction of the rotating shaft and is integrally formed with each blade end at the radially outer side of the plurality of blades. In the axial flow fan, a portion on the downstream side in the direction of the air flow formed by the rotation of the axial flow fan is positioned inside the bell mouth, and a portion on the upstream side thereof is positioned outside the bell mouth, and the ring part is disposed further to the upstream side than the bell mouth inside the housing.

Description

Outdoor unit and refrigeration cycle device

[0001] The present disclosure relates to an outdoor unit for a refrigeration cycle device and a refrigeration cycle device.

[0002] Conventionally, an outdoor unit intended to increase fan efficiency has been proposed (see, for example, Patent Document 1). Patent Document 1 discloses a refrigeration device used as an outdoor unit and a blower device used for the refrigeration device. This blower device for the refrigeration device has a bellmouth and a fan having a plurality of blades disposed inside the bellmouth, and a ring is connected to the outer peripheral end of the fan blades. The blower device of Patent Document 1 has a ring provided over the entire fan in the axial direction of the rotation axis, and particularly has a ring inclined toward the bellmouth side on the downstream side of the fan, thereby increasing the static pressure and increasing the fan efficiency.

[0003] Japanese Patent Application Laid-Open No. 2021-124023

[0004] In order to improve the performance of the outdoor unit of the refrigeration cycle device, an increase in the air volume by the fan is required. Also, the outdoor unit is required to be lightweight in order to reduce transportation costs or manufacturing costs. To increase the air volume by the fan, it is conceivable to increase the diameter of the fan. However, in the outdoor unit of Patent Document 1, in the blower device, since the bellmouth is located on the outer peripheral side of the ring so as to enclose the fan, the diameter of the fan cannot be increased. Also, in the outdoor unit of Patent Document 1, since a ring is provided over the entire fan in the axial direction of the rotation axis, a space between the bellmouth and the ring is required, and thus the diameter of the fan needs to be reduced. Therefore, in the outdoor unit of Patent Document 1, since the diameter of the blade needs to be reduced by the thickness of the ring, there is a risk that the air volume will decrease compared to the case without the ring.

[0005] Furthermore, the outdoor unit blower described in Patent Document 1 is heavier than a fan without a ring because a ring is provided around the entire fan in the axial direction of the rotating shaft. Also, in the outdoor unit blower described in Patent Document 1, if the fan height is increased to increase the airflow, that is, if the entire fan is enlarged in the axial direction of the rotating shaft, the weight of the ring portion increases, and the weight of the entire fan also increases.

[0006] This disclosure aims to solve the aforementioned problems and to provide an outdoor unit and refrigeration cycle device that increase airflow by a fan while keeping the increase in weight low.

[0007] The outdoor unit according to this disclosure comprises a box-shaped housing having an intake port and an outlet port, and an axial fan disposed inside the housing and rotating to form an airflow. The housing constitutes the outlet and has a cylindrical bell mouth surrounding the outer circumference of the axial fan. The axial fan has a hub that is rotationally driven to form a rotation axis, a plurality of blades formed around the hub and extending radially outward from the hub, and a cylindrical ring portion that is annular when viewed in the axial direction of the rotation axis and is integrally formed with each radially outer blade end of the plurality of blades. The downstream portion of the axial fan is located inside the bell mouth in the direction of airflow formed by the rotation of the axial fan, and the upstream portion is located outside the bell mouth. The ring portion is located inside the housing upstream of the bell mouth.

[0008] The refrigeration cycle system according to this disclosure comprises an outdoor unit having the above configuration and an indoor unit having an indoor heat exchanger and a blower fan.

[0009] According to this disclosure, the outdoor unit and refrigeration cycle device can increase the airflow from the fan while keeping the increase in weight low.

[0010] This is a schematic front view showing the external configuration of the outdoor unit according to Embodiment 1. This is a schematic side view showing the external configuration of the outdoor unit according to Embodiment 1. This is a schematic cross-sectional view showing the internal configuration of the outdoor unit according to Embodiment 1. This is a top view showing the schematic configuration of the axial fan according to Embodiment 1. This is a side view showing the schematic configuration of the axial fan according to Embodiment 1. This is a top view showing the configuration of the motor support in the outdoor unit according to Embodiment 1. This is a top view showing another example of the configuration of the motor support in the outdoor unit according to Embodiment 1. This is a side view showing a schematic configuration of a modified example of the axial fan according to Embodiment 1. This is a perspective view of another form of the outdoor unit according to Embodiment 1, viewed from the outlet side. This is a diagram showing the outdoor unit shown in Figure 9 with the fan grille removed. This is a conceptual diagram explaining the internal configuration of the outdoor unit shown in Figure 9 from the top side. This is a schematic cross-sectional view of the bell mouth portion showing the internal configuration of the outdoor unit according to Embodiment 1. This is a schematic cross-sectional view of the bell mouth portion showing the internal configuration of the outdoor unit according to Embodiment 2. This is a top view showing the schematic configuration of the axial fan according to Embodiment 3. This is a side view showing the schematic configuration of the axial fan according to Embodiment 3. This is a schematic cross-sectional view of the bell mouth portion showing the internal configuration of the outdoor unit according to Embodiment 3. This is a schematic cross-sectional view of the bell mouth portion showing the internal configuration of a modified example of the outdoor unit according to Embodiment 3. This is a conceptual diagram showing the airflow pattern passing through the ring portion in the case a comparative example. This is a cross-sectional view showing the general configuration of the outdoor unit according to Embodiment 4. This is a cross-sectional view showing the general configuration of the outdoor unit according to Embodiment 5. This is a conceptual diagram showing the configuration of the refrigerant circuit of the refrigeration cycle device according to Embodiment 6.

[0011] Embodiments of this disclosure will be described below with reference to the drawings. This disclosure is not limited to the embodiments described below, and can be modified in various ways without departing from the spirit of this disclosure. Furthermore, this disclosure includes all possible combinations of the configurations shown in each of the embodiments described below. In particular, the combinations of components are not limited to the combinations in each embodiment, and components described in one embodiment can be applied to another embodiment. In addition, in the following description, terms indicating direction (e.g., "up," "down," "right," "left," "front," "back," etc.) will be used as appropriate to facilitate understanding, but these are for illustrative purposes only and do not limit this disclosure. Also, in each drawing, components with the same reference numerals are the same or equivalent, and this is common throughout the entire specification. Note that the relative dimensions or shapes of each component in each drawing may differ from those of the actual components.

[0012] Embodiment 1. Figure 1 is a schematic front view showing the external configuration of the outdoor unit 100 according to Embodiment 1. Figure 2 is a schematic side view showing the external configuration of the outdoor unit 100 according to Embodiment 1. Figure 3 is a schematic cross-sectional view showing the internal configuration of the outdoor unit 100 according to Embodiment 1. Figure 3 is a conceptual diagram of the cross section of the outdoor unit 100 at the A-A line shown in Figure 2, viewed in the direction of the arrow. For the purpose of explaining the outdoor unit, arrow X in Figures 1 to 3 indicates the front-to-back direction of the outdoor unit 100, arrow Y indicates the left-to-right direction of the outdoor unit 100, and arrow Z indicates the vertical up-and-down direction. The outdoor unit 100 will be explained using Figures 1 to 3.

[0013] [Outdoor unit 100] The outdoor unit 100 is used in a refrigeration cycle device 300 (see Figure 22), which will be described later, such as an air conditioning system. The outdoor unit 100 comprises a box-shaped housing 10 having an intake port 11 and an outlet port 12, and at least one axial flow fan 20 which is arranged inside the housing 10 and rotates to form an airflow.

[0014] The outdoor unit 100 is a so-called top-flow type outdoor unit in which an air outlet 12 is formed on the upper surface of the housing 10, and air is blown upward through the outlet 12 by the drive of an axial flow fan 20. However, the outdoor unit 100 is not limited to a top-flow type outdoor unit, and may be an outdoor unit with other configurations, such as an outdoor unit in which an air outlet 12 is formed on the side of the housing 10 and air is blown out to the side of the housing 10.

[0015] (Housing 10) As shown in Figures 1 and 3, the housing 10 is formed in the shape of an inverted triangle when viewed from the front, and in the shape of a rectangle when viewed from the side. The outdoor unit 100 has an air intake port 11 formed on the side of the housing 10 and an air outlet port 12 formed on the top surface of the housing 10. The shape of the housing 10 is not limited to this shape, and other shapes such as a rectangular parallelepiped are also possible. The housing 10 is made of metal, for example, but the material that makes up the housing 10 is not limited to metal.

[0016] The housing 10 has a bottom portion 13 that constitutes the bottom of the housing 10 and a top portion 16 that constitutes the top of the housing 10. The housing 10 also has a pair of first side portions 14 that constitute the sides of the housing 10 in the front-rear direction and a pair of second side portions 15 that constitute the sides of the housing 10 in the left-right direction.

[0017] The first side portion 14 is formed in a plate shape and covers the heat exchanger 60 located inside the housing 10 in the front-to-back direction, thereby closing the side of the housing 10. The second side portion 15 is formed in a frame shape, and an air intake port 11 is formed in the second side portion 15.

[0018] In the outdoor unit 100, a heat exchanger 60 is positioned near the intake port 11 inside the housing 10, and the heat exchanger 60 is exposed at the intake port 11 of the housing 10. Air drawn into the housing 10 by the drive of the axial flow fan 20 is drawn in from the intake port 11, passes through the heat exchanger 60 located at the intake port 11, and heads towards the outlet port 12. The detailed configuration and internal structure of the housing 10 will be described later.

[0019] (Axial flow fan 20) The axial flow fan 20 is an axial flow type impeller, such as a propeller fan, and is a device that forms a fluid flow. The axial flow fan 20 forms an airflow for efficient heat exchange in the heat exchanger 60. The axial flow fan 20 is located in the upper part inside the housing 10. The axial flow fan 20 is provided at the outlet 12. Inside the housing 10, a portion of the upstream side of the blades 22 of the axial flow fan 20 protrudes upstream from inside the bell mouth 30. In other words, the axial flow fan 20 constitutes a semi-open type blower in which the intake side of the outer circumference of the axial flow fan 20 is not surrounded by the bell mouth 30 and is open.

[0020] The axial flow fan 20 rotates around a rotation axis RA that extends vertically through the housing 10, drawing air into the housing 10 through the intake port 11 on the second side surface 15 of the housing 10, and blowing the heat-exchanged air upward through the heat exchanger 60. The axial flow fan 20 forms an airflow that passes through the heat exchanger 60 and is discharged from the outlet 12 of the bell mouth 30. The axial flow fan 20 is housed inside the bell mouth 30, with its downstream portion 20c enclosed by the bell mouth 30. The number of axial flow fans 20 arranged inside the housing 10 may be one or multiple.

[0021] The axial flow fan 20 is positioned inside the bell mouth 30 such that the line 20a of the rotation axis RA of the axial flow fan 20 extends in the vertical direction. The axial flow fan 20 has a hub 21 provided on the axis of the rotation axis RA, a plurality of blades 22 provided on the outer circumference of the hub 21, and a ring portion 23 formed integrally with a part of the outer edge of the blades. A more detailed configuration of the axial flow fan 20 will be described later.

[0022] (Detailed configuration and internal configuration of the housing 10) The housing 10 constitutes the air outlet 12 and has at least one cylindrical bell mouth 30 surrounding the outer circumference of the axial flow fan 20. The housing 10 also has a motor 50 inside the bell mouth 30. Furthermore, the housing 10 has a heat exchanger 60 inside the housing 10 in the region upstream of the axial flow fan 20.

[0023] (Bell mouth 30) The bell mouth 30 is located on the upper part of the housing 10 and is located on the upper surface of the housing 10. The bell mouth 30 is made of metal, for example, but the material that makes up the bell mouth 30 is not limited to metal. The bell mouth 30 constitutes the air outlet 12. The bell mouth 30 surrounds the outer circumference of the blades 22 of the axial flow fan 20.

[0024] The bell mouth 30 regulates the airflow formed by the axial fan 20. The bell mouth 30 rectifies the air blown out of the housing 10 by the axial fan 20 and allows it to flow out to the outside of the housing 10. For example, the bell mouth 30 rectifies the air blown out of the axial fan 20, converts the dynamic pressure to static pressure, restores the pressure, and reduces the velocity of the airflow.

[0025] In Figure 2, there are two bell mouths 30, but in the enclosure 10, there may be one or more bell mouths 30. The bell mouths 30 are provided in correspondence with the axial flow fans 20. In other words, as a general rule, the number of bell mouths 30 is the same as the number of axial flow fans 20.

[0026] The bell mouth 30 is formed in a cylindrical shape. The bell mouth 30 is formed, for example, in a cylindrical shape. The bell mouth 30 is formed in a hollow shape, with an opening 30a formed inside from the upstream end 30b to the downstream end 30c. The bell mouth 30 is formed in an annular shape along the rotation direction of the axial flow fan 20. When viewed in the axial direction of the rotation axis RA of the axial flow fan 20, the bell mouth 30 may be formed in a circular shape, for example, or in an elliptical shape. The bell mouth 30 is formed to extend along the axis of the rotation axis RA of the axial flow fan 20.

[0027] As shown in Figure 3, for example, the bell mouth 30 has both ends in a trumpet shape in the direction along the axial axis RA of the axial flow fan 20, with the end portion being larger and the central portion being smaller. However, the shape of the bell mouth 30 is not limited to this shape; for example, only one end of the two ends may be formed in a trumpet shape, or the entire structure may be formed in a straight tube shape with a constant opening diameter. Here, the shape of the bell mouth 30 shown in Figure 3 will be described.

[0028] The first direction F is defined as the direction of airflow formed by the rotation of the blades 22 of the axial fan 20, which is the direction from the inside to the outside of the housing 10 through the opening 30a of the bell mouth 30. As the airflow moves toward the first direction F, the opening diameter of the flow path formed by the opening 30a of the bell mouth 30 decreases, becoming a flow path of a constant opening diameter, and then becoming a flow path where the opening diameter expands. In the first direction F, the bell mouth 30 has an upstream section 31, an intermediate section 32, and a downstream section 33, moving from the upstream side to the downstream side of the airflow through the opening 30a.

[0029] The upstream section 31 gradually narrows in width as it moves toward the first direction F. In the first direction F, the upstream section 31 is formed so that the opening diameter on the upstream side of the airflow is larger than the opening diameter on the downstream side. The upstream section 31 is formed so that the opening diameter gradually decreases as it moves toward the first direction F, and the flow path gradually narrows from the upstream side to the downstream side. The upstream section 31 is formed in a flared or trumpet shape, for example, with the base widening from the downstream end 30c to the upstream end 30b.

[0030] In the outdoor unit 100 shown in Figure 3, the upstream portion 31 of the bell mouth 30 is connected to the top surface 16 of the housing 10. The upstream portion 31 and the top surface 16 may be formed as separate parts or as a single unit. The upstream portion 31 of the bell mouth 30 surrounds the outer circumference of the blades 22 of the axial flow fan 20. The upstream portion 31 of the bell mouth 30 does not surround the ring portion 23 of the axial flow fan 20, which will be described later.

[0031] The intermediate section 32 has a constant width in the flow path from upstream to downstream in the direction of airflow formed by the rotation of the blades 22 of the axial flow fan 20. The intermediate section 32 is formed in a straight tube shape with a constant opening diameter in the first direction F. The intermediate section 32 of the bell mouth 30 surrounds the outer circumference of the blades 22 of the axial flow fan 20. The intermediate section 32 of the bell mouth 30 does not surround the ring section 23 of the axial flow fan 20, which will be described later.

[0032] The downstream section 33 gradually widens in width as it moves toward the first direction F. In the first direction F, the downstream section 33 is formed so that the opening diameter on the downstream side of the airflow is larger than the opening diameter on the upstream side. The downstream section 33 is formed so that the opening diameter gradually increases as it moves toward the first direction F, and the flow path gradually widens from the upstream side to the downstream side. The downstream section 33 is formed in a flared or trumpet shape, for example, with the base widening from the upstream end 30b to the downstream end 30c.

[0033] The downstream portion 33 of the bell mouth 30 may or may not surround the outer circumference of the blades 22 of the axial fan 20. The downstream portion 33 of the bell mouth 30 does not surround the ring portion 23 of the axial fan 20, which will be described later.

[0034] The bell mouth 30 constitutes the air outlet 12 of the housing 10. The airflow formed by the axial fan 20 passes through the opening 30a inside the bell mouth 30 and is discharged to the outside of the housing 10. The axial fan 20 is installed inside the housing 10, enclosed by the bell mouth 30.

[0035] (Motor support 40) The bell mouth 30 includes a motor support 40 that supports the motor 50. The motor support 40 is provided at the outlet 12. The motor support 40 is provided, for example, at the downstream portion 33 of the bell mouth 30.

[0036] The motor support 40 supports the motor 50 from the downstream side in the airflow. The motor support 40 may also support the axial fan 20 via the motor 50. The motor support 40 is surrounded by the downstream portion 33 of the bell mouth 30. As a result, when viewed in the radial direction RD around the axis of the rotating shaft RA, the motor support 40 overlaps with the bell mouth 30. An example configuration of the motor support 40 will be described later.

[0037] (Motor 50) The housing 10 has a motor 50 inside the bell mouth 30 that rotates the axial flow fan 20. The motor 50 is fixed to and supported by a motor support 40.

[0038] The motor 50 is a power generator and the drive source for the axial flow fan 20. The motor 50 is configured to drive the axial flow fan 20. The motor 50 rotates when power is supplied to it, providing driving force to the axial flow fan 20. The motor 50 has a rotating shaft 50a. The rotating shaft 50a of the motor 50 is connected to the hub 21 of the axial flow fan 20. The motor 50 is positioned coaxially with the axial flow fan 20.

[0039] The motor 50 rotates the axial flow fan 20 by rotating its rotating shaft 50a. In the outdoor unit 100, the axial flow fan 20 rotates due to the drive of the motor 50, and an airflow is formed. The motor 50 and motor support 40 are positioned above the axial flow fan 20. That is, the motor 50 and motor support 40 are located downstream of the axial flow fan 20 in the direction of the airflow formed by the rotation of the axial flow fan 20. The airflow formed by the axial flow fan 20 due to the drive of the motor 50 passes through the heat exchanger 60 located inside the housing 10.

[0040] (Heat exchanger 60) The outdoor unit 100 has at least one heat exchanger 60 that functions as a condenser for condensing the refrigerant or an evaporator for evaporating the refrigerant. The heat exchanger 60 is, for example, a fin-tube heat exchanger. The heat exchanger 60 is located inside the housing 10 in a region upstream of the axial fan 20 in the direction of airflow formed by the rotation of the axial fan 20. In the case of the top-flow type outdoor unit shown in Figures 1 to 3, the heat exchanger 60 is located below the axial fan 20.

[0041] The heat exchanger 60 is located on the side of the housing 10. The heat exchanger 60 is located at the intake port 11 of the second side portion 15 of the housing 10. The heat exchanger 60 is located inside the housing 10 so as to cover the intake port 11. The heat exchangers 60 are arranged, for example, so as to face each other in the horizontal direction. The pair of heat exchangers 60 may be arranged, for example, in a V-shape when viewed from the side. The heat exchangers 60 may be arranged on three sides of the housing 10 in a U-shape when viewed from above (not shown).

[0042] The heat exchanger 60 performs heat exchange between the refrigerant flowing inside the heat exchanger 60 and the outdoor air. When the outdoor unit 100 is used in an air conditioning system, the heat exchanger 60 functions as an evaporator during the heating operation of the air conditioning system and as a condenser during the cooling operation of the air conditioning system. Air is supplied to the heat exchanger 60 by an axial flow fan 20 to improve the efficiency of heat exchange between the refrigerant and the outdoor air.

[0043] (Detailed configuration of the axial fan 20) Figure 4 is a top view showing the schematic configuration of the axial fan 20 according to Embodiment 1. Figure 5 is a side view showing the schematic configuration of the axial fan 20 according to Embodiment 1. Figure 4 is a view of the axial fan 20 from the air outlet side in the axial direction of the rotating shaft RA, and Figure 5 is a view of the axial fan 20 from a direction perpendicular to the rotating shaft RA. The rotation direction R indicated by the arrow in the figure indicates the direction in which the axial fan 20 rotates. Furthermore, the circumferential direction CD indicated by the double-headed arrow in the figure indicates the circumferential direction of the axial fan 20.

[0044] Also, the radial direction RD indicated by the double-headed arrow in the figures of FIGS. 4 and 5 represents the radial direction of the axial flow fan 20. The radial direction RD is a direction perpendicular to the rotation axis RA of the axial flow fan 20 and represents the radial direction of the axial flow fan 20. In the radial direction RD, the portion on the RD2 side is located on the outer peripheral side with respect to the portion on the RD1 side, and the portion on the RD1 side is located on the inner peripheral side with respect to the portion on the RD2 side. That is, the RD1 side of the axial flow fan 20 is the inner peripheral side of the axial flow fan 20, and the RD2 side of the axial flow fan 20 is the outer peripheral side of the axial flow fan 20.

[0045] The axial flow fan 20 according to Embodiment 1 will be described with reference to FIGS. 1 to 5. The axial flow fan 20 is used in the outdoor unit 100 and is used, for example, as a fan of a refrigeration cycle device such as an air conditioner. The axial flow fan 20 forms a fluid flow by rotating in the rotation direction R about the rotation axis RA. The fluid is, for example, a gas such as air, and the axial flow fan 20 forms an air flow, which is an air flow, by rotating.

[0046] The front side with respect to the plane of FIG. 4 is the downstream side with respect to the axial flow fan 20 in the direction of fluid flow, and the back side with respect to the plane of FIG. 4 is the upstream side with respect to the axial flow fan 20 in the direction of fluid flow. Therefore, FIG. 4 is a view of the axial flow fan 20 seen from the downstream side in the direction of fluid flow. The upstream side with respect to the axial flow fan 20 is the air suction side with respect to the axial flow fan 20, and the downstream side with respect to the axial flow fan 20 is the air blowing side with respect to the axial flow fan 20.

[0047] As shown in FIGS. 4 and 5, the axial flow fan 20 includes a hub 21 that is rotationally driven to form a rotation axis RA, and a plurality of blades 22 that are formed around the hub 21 and extend radially outward from the hub 21 in the radial direction RD. Further, the axial flow fan 20 is formed in an annular shape when viewed in the axial direction of the rotation axis RA, and has a cylindrical ring portion 23 formed integrally with each blade end on the outer side in the radial direction RD of the plurality of blades 22. Each blade end of the plurality of blades 22 is an end portion on the side opposite to the hub 21 in the blade 22 in the radial direction RD.

[0048] The axial flow fan 20 may be a so-called bossless fan in which the front edge portions and the rear edge portions of adjacent blades 22 among the plurality of blades 22 are connected so as to form a continuous surface without passing through a boss. The axial flow fan 20 is, for example, molded from resin, but may be formed from metal.

[0049] (Hub 21) The hub 21 is connected to the rotating shaft 50a of the motor 50 as shown in FIG. 3. The hub 21 may be configured, for example, in a cylindrical shape, or may be configured in a plate shape such as a disk shape. The hub 21 only needs to be connected to the rotating shaft 50a of the motor 50 as described above, and its shape is not limited.

[0050] The hub 21 is rotationally driven by the motor 50 to form an imaginary rotation axis RA. The hub 21 rotates about the rotation axis RA. The rotation direction R of the axial flow fan 20 is, for example, counterclockwise when viewed from the downstream side of the axial flow fan 20 as indicated by the arrow in FIG. 4. However, the rotation direction R of the axial flow fan 20 is not limited to counterclockwise. The hub 21 may rotate clockwise by changing the attachment angle of the blade 22 or the orientation of the blade 22 or the like.

[0051] (Blade 22) The blade 22 is provided around the hub 21 and is formed so as to extend from the hub 21 toward the outer peripheral side in the radial direction RD. The plurality of blades 22 are arranged radially outward from the hub 21 around the rotation axis RA. The plurality of blades 22 are provided separately from each other in the circumferential direction CD. In the first embodiment, an axial flow fan 20 having five blades 22 is illustrated, but the number of blades 22 is not limited to five. The number of blades 22 may be four or less, or six or more. The plurality of blades 22 are connected by a ring portion 23 described later.

[0052] Multiple wings 22 are formed around the hub 21, each with the same shape. Furthermore, the multiple wings 22 are arranged at equal intervals in the circumferential direction CD. However, the wings 22 are not limited to this configuration. The multiple wings 22 may be formed with different shapes, and may be arranged at different intervals in the circumferential direction CD.

[0053] The wing 22 is formed in the shape of a forward-swept wing, with the outer circumferential portion protruding further forward in the rotational direction R than the inner circumferential portion. However, the wing 22 is not limited to a forward-swept wing and may be formed in other shapes. When viewed in the axial direction of the rotation axis RA, the wing 22 is formed in a substantially triangular shape, where the width of the circumferential CD of the outer circumferential portion is greater than the width of the circumferential CD of the inner circumferential portion. However, the wing 22 is not limited to being formed in a substantially triangular shape when viewed in the axial direction of the rotation axis RA.

[0054] The wing 22 has a leading edge 22a, a trailing edge 22b, an inner edge 22c which is connected to the hub 21, and an outer edge 22d which forms the outer edge between the leading edge 22a and the trailing edge 22b. The leading edge 22a constitutes the edge portion on the forward side in the rotational direction R of the wing 22. That is, the leading edge 22a is located in front of the trailing edge 22b in the rotational direction R. The leading edge 22a is located upstream of the trailing edge 22b in the direction of fluid flow.

[0055] The trailing edge 22b constitutes the rearward edge portion of the blade 22 in the rotational direction R. That is, the trailing edge 22b is located behind the leading edge 22a in the rotational direction R. The trailing edge 22b is located downstream of the leading edge 22a in the direction of fluid flow. The axial flow fan 20 has a leading edge 22a as the blade end facing the rotational direction R of the axial flow fan 20, and a trailing edge 22b as the blade end opposite to the leading edge 22a in the rotational direction R.

[0056] The outer edge portion 22d is a portion that extends forward and backward in the rotational direction R, forming the part between the outermost periphery of the leading edge portion 22a and the outermost periphery of the trailing edge portion 22b. In the axial flow fan 20, the outer edge portion 22d constitutes the outer edge of the blade on the radial side RD. The outer edge portion 22d forms the outer edge of the blade 22.

[0057] The outer edge portion 22d is formed in an arc shape when viewed in the axial direction of the rotation axis RA. For example, the outer edge portion 22d includes a portion formed in a circular arc shape when viewed in the axial direction of the rotation axis RA. However, the outer edge portion 22d is not limited to a configuration in which it is formed in an arc shape when viewed in the axial direction of the rotation axis RA.

[0058] When viewed in the axial direction of the rotation axis RA, the blade 22 is formed such that the length of the outer edge 22d in the circumferential direction CD is longer than the length of the inner edge 22c in the circumferential direction CD. However, the relationship between the length of the outer edge 22d and the length of the inner edge 22c in the circumferential direction CD of the blade 22 is not limited to this configuration. For example, the length of the outer edge 22d and the length of the inner edge 22c in the circumferential direction CD of the blade 22 may be equal, or the length of the inner edge 22c may be longer than the length of the outer edge 22d.

[0059] As shown in Figure 4, each of the multiple blades 22 has a leading edge portion 22da and a trailing edge portion 22db at its outer edge portion 22d, which is the outermost end. In the direction of airflow formed by the axial flow fan 20, the leading edge portion 22da is located upstream of the trailing edge portion 22db, and the trailing edge portion 22db is located downstream of the leading edge portion 22da. That is, in the circumferential direction of the axial flow fan 20, the leading edge portion 22da is located on the leading edge portion 22a side relative to the trailing edge portion 22db, and the trailing edge portion 22db is located on the trailing edge portion 22b side relative to the leading edge portion 22da.

[0060] At the outer edge portion 22d of the blade 22, the leading edge portion 22da is the part connected to the ring portion 23. That is, the leading edge portion 22da is connected to the ring portion 23 and is formed integrally with the ring portion 23. At the outer edge portion 22d of the blade 22, the portion closer to the leading edge portion 22da is connected to the ring portion 23 and is formed integrally with the ring portion 23 than the portion closer to the trailing edge portion 22db. That is, in the axial flow fan 20, the upstream portion 20b of the blade 22 is formed integrally with the ring portion 23.

[0061] At the outer edge portion 22d of the blade 22, the trailing edge portion 22db is the part that is not connected to the ring portion 23. That is, the trailing edge portion 22db is not connected to the ring portion 23 and is not formed integrally with the ring portion 23. At the outer edge portion 22d of the blade 22, the portion closer to the trailing edge portion 22db is not connected to the ring portion 23 and is not formed integrally with the ring portion 23 compared to the portion closer to the leading edge portion 22da. That is, in the axial flow fan 20, the downstream portion 20c of the blade 22 is not formed integrally with the ring portion 23.

[0062] It should be noted that the upstream portion 20b and the downstream portion 20c of the wing 22 described above do not have clearly defined boundaries. The upstream portion 20b and the downstream portion 20c of the wing 22 are defined as the upstream portion 20b of the wing 22 if they are located relatively to the upstream portion of the wing 22, and as the downstream portion 20c of the wing 22 if they are located relatively to the downstream portion of the wing 22. For example, the upstream portion 20b and the downstream portion 20c of the wing 22 may be determined using the central portion of the outer edge 22d along its length as a reference. In this case, the portion located from the central portion of the outer edge 22d toward the leading edge 22a may be defined as the upstream portion 20b of the wing 22, and the portion located from the central portion of the outer edge 22d toward the trailing edge 22b may be defined as the downstream portion 20c of the wing 22.

[0063] Alternatively, when identifying the upstream portion 20b and the downstream portion 20c of the wing 22, the central portion between the position of the leading edge outer edge 22da and the position of the trailing edge outer edge 22db in the axial direction of the rotation axis RA may be used as a reference when viewed perpendicular to the rotation axis RA. In this case, the portion located on the leading edge outer edge 22da side from this central portion may be defined as the upstream portion 20b of the wing 22, and the portion located on the trailing edge outer edge 22db side from this central portion may be defined as the downstream portion 20c of the wing 22.

[0064] As shown in Figure 3, when the axial fan 20 is placed inside the housing 10, it is positioned in the opening 30a which is inside the bell mouth 30. As shown in Figure 3, when the axial fan 20 is placed inside the housing 10, the downstream portion 20c of the blades 22 faces the inner wall surface 30d of the bell mouth 30.

[0065] The inner edge portion 22c is a portion that extends forward and backward in the rotational direction R, forming the portion between the innermost circumference of the leading edge portion 22a and the innermost circumference of the trailing edge portion 22b. In the axial flow fan 20, the inner edge portion 22c forms the inner circumference end in the radial direction RD. The inner edge portion 22c forms the inner circumference of the blade 22 and constitutes the root portion of the blade 22.

[0066] The inner edge portion 22c is formed in an arc shape when viewed in the axial direction of the rotation axis RA. However, the inner edge portion 22c is not limited to being formed in an arc shape when viewed in the axial direction of the rotation axis RA. The inner edge portion 22c of the wing 22 is connected to the hub 21, for example, by being formed integrally with the hub 21. As an example, the inner edge portion 22c of the wing 22 is formed integrally with the outer circumferential wall of the cylindrical hub 21.

[0067] The blades 22 are formed at an angle to a plane perpendicular to the rotation axis RA. The blades 22 transport fluid by pushing the fluid present between them with their blade surfaces 22g as the axial flow fan 20 rotates. At this time, of the blade surfaces 22g of the blades 22, the side on which the fluid is pushed and the pressure increases when the axial flow fan 20 rotates is designated as the positive pressure surface 22e, and the side on which the pressure decreases is designated as the negative pressure surface 22f, which forms the back surface of the positive pressure surface 22e.

[0068] Each of the multiple blades 22, as shown in Figures 4 and 5, includes a positive pressure surface 22e on the blade surface 22g of the blade 22, which is the side that pushes the fluid and increases the pressure when the blade 22 rotates, and a negative pressure surface 22f which is the side that is the reverse side of the positive pressure surface 22e and is the side that decreases the pressure.

[0069] On the blade surface 22g, the surface facing upstream of the blade 22 becomes the negative pressure surface 22f, and the surface facing downstream becomes the positive pressure surface 22e, in the direction of fluid flow. Furthermore, the positive pressure surface 22e is the surface facing the rotation direction R, and the negative pressure surface 22f is the surface facing the opposite direction of rotation R. In Figure 4, the far side of the blade 22 becomes the negative pressure surface 22f, and the near side of the blade 22 becomes the positive pressure surface 22e.

[0070] (Ring portion 23) The axial flow fan 20 has a ring portion 23 on the outer circumference of the blades 22. As shown in Figure 4, the ring portion 23 is formed in an annular shape when viewed in the axial direction of the rotation axis RA, and is formed integrally with each blade end of the plurality of blades 22 on the outer side in the radial direction RD. The ring portion 23 is formed in a cylindrical shape so as to extend in the axial direction of the rotation axis RA. More specifically, the ring portion 23 is formed in a cylindrical shape so as to extend in the axial direction of the rotation axis RA. The ring portion 23 is formed in a straight tube shape so as to extend in the axial direction of the rotation axis RA. The ring portion 23 is formed in an annular shape when viewed in the axial direction of the rotation axis RA.

[0071] The ring portion 23 is formed to surround the multiple blades 22 when viewed in the axial direction of the rotation axis RA. The axial flow fan 20 has the inner wall surface 23a of the ring portion 23 and a part of the outer edge portion 22d of the blades 22 integrally formed. In the axial flow fan 20, a space S through which air escapes in the axial direction of the rotation axis RA is formed by two adjacent blades 22 in the circumferential direction CD and the inner circumferential portion of the ring portion 23.

[0072] Multiple blades 22 are connected by a ring portion 23. The ring portion 23 is provided on the upstream portion 20b of the blade 22 in the direction of airflow formed by the axial flow fan 20. That is, the ring portion 23 is provided closer to the leading edge 22a of the blade 22 than to the trailing edge 22b.

[0073] As shown in Figure 3, the axial fan 20 has a downstream portion 20c located inside the bell mouth 30 in the direction of airflow formed by the rotation of the axial fan 20, and an upstream portion 20b located outside the bell mouth 30. The upstream portion 20b of the axial fan 20 protrudes from the bell mouth 30 in the direction of airflow formed by the rotation of the axial fan 20 and is located inside the housing 10.

[0074] The axial flow fan 20 has an upstream portion 20b that protrudes below the bell mouth 30 in the direction of airflow formed by the rotation of the axial flow fan 20. The axial flow fan 20 may also have an upstream portion 20b that is located below the top surface 16 of the housing 10 in the direction of airflow formed by the rotation of the axial flow fan 20.

[0075] The ring portion 23 of the axial fan 20 is located inside the housing 10, upstream of the bell mouth 30. The ring portion 23 is provided inside the housing 10 on the portion of the blades 22 that protrudes from the bell mouth 30. The ring portion 23 of the axial fan 20 is not located inside the opening 30a of the bell mouth 30 and is not enclosed within the bell mouth 30. The ring portion 23 of the axial fan 20 is located outside the bell mouth 30. The ring portion 23 of the axial fan 20 is located inside the housing 10 in the space where the heat exchanger 60 is located.

[0076] (Example of Motor Support 40 Configuration) Figure 6 is a top view showing the configuration of the motor support 40 in the outdoor unit 100 according to Embodiment 1. Figure 6 is a conceptual diagram of the outdoor unit 100 viewed from above, showing the bell mouth 30 portion. As shown in Figure 6, the motor support 40 has a boss portion 41 and a plurality of radial bars 42.

[0077] The boss portion 41 is located at the center of the motor support 40. The boss portion 41 is positioned on the axis of the rotation axis RA of the axial flow fan 20. The boss portion 41 has a disc-shaped or cylindrical shape centered on the axis of the rotation axis RA. The motor 50 is fixed to the boss portion 41.

[0078] Each of the multiple radial struts 42 has a stator vane function. The radial struts 42 are blades or wings fixed to the bell mouth 30 of the housing 10, and the radial struts 42 themselves do not rotate. The outdoor unit 100 is configured with stages by a combination of radial struts 42 that act as non-rotating stator vanes and blades 22 of the axial flow fan 20 that act as rotating rotors, converting fluid energy into rotational motion. For example, each of the radial struts 42 has a cross-sectional shape that follows the airflow and has the function of straightening the swirling flow generated by the axial flow fan 20.

[0079] Multiple radial bars 42 are arranged at intervals from each other in the circumferential direction CD of the rotation axis RA. Each of the multiple radial bars 42 extends in the radial direction RD around the rotation axis RA. The radial bars 42 are attached to the inner wall surface 30d of the bell mouth 30. In the radial direction RD, the inner circumferential end 42a of one end of the radial bar 42 is connected to the boss portion 41. In the radial direction RD, the outer circumferential end 42b of the other end of the radial bar 42 is connected to the downstream portion 33 of the bell mouth 30.

[0080] The radial braces 42 are formed in a flat plate shape. The radial braces 42 may be formed to be inclined with respect to a plane perpendicular to the rotation axis RA, for example. That is, one plate surface of the radial brace 42 may be inclined so that it faces the circumferential direction CD and the downstream side of the airflow passing through the bell mouth 30, and the other plate surface may be inclined so that it faces the circumferential direction CD and the upstream side of the airflow passing through the bell mouth 30. The radial braces 42 are not limited to this configuration, and the plate surfaces of the radial braces 42 may be configured to face the plate surfaces of adjacent radial braces 42, and to be aligned with the axial direction of the rotation axis RA.

[0081] Figure 7 is a top view showing another configuration example of the motor support 40 in the outdoor unit 100 according to Embodiment 1. Figure 7 conceptually shows the motor support 40, and the axial flow fan 20 and other details are omitted. The motor support 40 may have a plurality of circumferential supports 43 as shown in Figure 7.

[0082] Each of the circumferential struts 43 has a stator vane function. That is, each of the circumferential struts 43 has a cross-sectional shape that follows the airflow and has the function of straightening the swirling flow generated by the axial flow fan 20. Each of the multiple circumferential struts 43 extends in the circumferential direction CD around the rotation axis RA. The circumferential struts 43 intersect with the radial struts 42. The circumferential struts 43 are connected to the radial struts 42 at each intersection.

[0083] When the axial flow fan 20 is driven by the motor 50, an upward airflow is generated inside the housing 10. Air flowing into the housing 10 from the side passes through the heat exchanger 60, the axial flow fan 20, the motor 50, and the motor support 40 in that order, and is exhausted upward from the outlet 12.

[0084] (Modified Version of Axial Fan 20) Figure 8 is a side view showing a schematic configuration of a modified version of the axial fan 20 according to Embodiment 1. As shown in Figure 8, the ring portion 23 of the axial fan 20 may have at least one notch 23b that constitutes a missing portion of the wall constituting the ring portion 23. By having the notch 23b, the ring portion 23 may be formed in a dashed line shape when viewed in the axial direction of the rotation axis RA, as a part of the wall in the circumferential direction CD is absent. By having the notch 23b, the ring portion 23 is formed to penetrate in the radial direction RD at the portion of the notch 23b.

[0085] Figure 9 is a perspective view of another configuration of the outdoor unit 100 according to Embodiment 1, viewed from the air outlet side. Figure 10 shows the outdoor unit 100 shown in Figure 9 with the fan grille 17 removed. Figure 11 is a conceptual diagram illustrating the internal configuration of the outdoor unit 100 as seen from the top side of the outdoor unit 100 shown in Figure 9. Note that the ring portion 23 is not shown in Figures 9 and 10. Also, the arrow AR in Figure 11 indicates the airflow. Parts having the same configuration as the outdoor unit 100 in Figures 1 to 8 are given the same reference numerals and their descriptions are omitted.

[0086] (Modified versions of the outdoor unit 100) The outdoor unit 100 described in Figures 1 to 8 was a so-called top-flow type outdoor unit, but the outdoor unit 100 is not limited to a top-flow type outdoor unit. For example, as shown in Figures 9 to 11, it may also be a side-flow type outdoor unit in which air is discharged from the side.

[0087] As shown in Figure 11, the outdoor unit 100 comprises a box-shaped housing 10 having an intake port 11 and an outlet port 12, and at least one axial fan 20 positioned inside the housing 10 and rotating to form an airflow. The housing 10 has a cylindrical bell mouth 30 that constitutes the outlet port 12 and surrounds the outer circumference of the axial fan 20.

[0088] The axial flow fan 20 has a downstream portion 20c located inside the bell mouth 30 in the direction of airflow formed by the rotation of the axial flow fan 20, and an upstream portion 20b located outside the bell mouth. The ring portion 23 is located inside the housing 10, upstream of the bell mouth 30.

[0089] As shown in Figure 9, the casing housing 10 is configured as a housing 10 having a pair of left and right sides 10a and side 10c, a front 10b, a rear 10d, a top 10e, and a bottom 10f. Openings (not shown) for drawing in air from the outside are formed on the side 10a and rear 10d.

[0090] As shown in Figure 10, on the front surface 10b, an air outlet 12 is formed in the front panel 10b1 as an opening for blowing air to the outside. Furthermore, as shown in Figure 9, the air outlet 12 is covered with a fan grill 17, thereby preventing contact between the axial flow fan 20 and objects outside the housing 10, and ensuring safety. Intake ports 11 are formed on the sides and back of the housing 10.

[0091] An axial flow fan 20 is housed inside the enclosure 10. The axial flow fan 20 is connected to a motor 50A. The axial flow fan 20 is connected to the rotating shaft 50B of the motor 50A, which is located on the rear side 10d, and is rotated by the motor 50A. The motor 50A is mounted on a motor support 40A. The motor support 40A is positioned between the motor 50 and the heat exchanger 60 and supports the motor 50.

[0092] In the outdoor unit 100 shown in Figure 11, the motor 50A and motor support 40A are located upstream of the axial flow fan 20, but the motor 50A and motor support 40A may also be located downstream of the axial flow fan 20. That is, the outdoor unit 100 shown in Figure 11 may have the motor support 40A provided inside the bell mouth 30 and the motor 50A located inside the bell mouth, similar to the top-flow type outdoor unit 100 shown in Figure 3.

[0093] The interior of the housing 10 is divided by a partition plate 10g, which is a wall, into a blower chamber 18 where the axial flow fan 20 is installed and a machine room 19 where the compressor 110 and the like are installed. Heat exchangers 60 are provided on the side 10a and rear 10d of the blower chamber 18, extending in a roughly L-shape in plan view. The shape of the heat exchangers 60 is not limited to this shape, and for example, they may be formed in a straight line in plan view.

[0094] A bell mouth 30 is provided downstream of the axial flow fan 20 located in the ventilation chamber 18. The bell mouth 30 has an upstream section 31, an intermediate section 32, and a downstream section 33.

[0095] The front end of the bell mouth 30 is connected to the front panel 10b1 of the outdoor unit 100 so as to form an air outlet 12. In the outdoor unit 100 shown in Figure 3, the upstream part 31 of the bell mouth 30 is connected to the top surface 16 of the housing 10, whereas in the outdoor unit 100 shown in Figure 11, the downstream part 33 of the bell mouth is connected to the front panel 10b1 of the housing 10. In the outdoor unit 100 shown in Figure 11, the bell mouth 30 may be integrally formed with the front panel 10b1, or it may be provided as a separate component that can be connected to the front panel 10b1.

[0096] The heat exchanger 60 provided on the suction side of the axial flow fan 20 is, for example, a fin-tube type heat exchanger. The heat exchanger 60 comprises, for example, a plurality of fins arranged in parallel so that their plate-like surfaces are parallel, and heat transfer tubes that penetrate each fin in the direction of the parallel arrangement. A refrigerant circulating in the refrigerant circuit flows through the heat transfer tubes.

[0097] The heat exchanger 60 is connected to the compressor 110 via refrigerant piping, etc., and is further connected to an indoor heat exchanger and expansion valve, etc. (not shown), to constitute the refrigerant circuit of the refrigeration cycle system. In addition, a circuit board box (not shown) is located in the machine room 19, and the equipment mounted inside the outdoor unit 100 is controlled by a control board (not shown) provided in this circuit board box.

[0098] [Effects of the Outdoor Unit 100] Figure 12 is a schematic cross-sectional view of the bell mouth 30 portion showing the internal configuration of the outdoor unit 100 according to Embodiment 1. In Figure 12, the motor 50 is not shown. The white arrows shown in Figure 12 indicate airflow. As shown in Figure 12, the axial flow fan 20 of the outdoor unit 100 has a downstream portion 20c located inside the bell mouth 30 in the direction of airflow formed by the rotation of the axial flow fan 20, and an upstream portion 20b located outside the bell mouth 30.

[0099] The axial flow fan 20 can be enlarged in the axial direction of the rotating shaft RA, thereby securing a larger blade area and increasing the airflow from the fan.

[0100] Furthermore, the ring portion 23 is positioned upstream of the bell mouth 30 inside the housing 10. The axial flow fan 20 can have a larger outer diameter for the blades 22 at the portion where the ring portion 23 is connected than the inner diameter of the bell mouth 30, thus allowing for a larger outer diameter for the blades 22 compared to an axial flow fan where the ring portion is positioned inside the bell mouth. Compared to an axial flow fan where the ring portion is positioned inside the bell mouth, the axial flow fan 20 can secure a larger blade area at the portion of the blades 22 connected to the ring portion 23, thereby increasing the airflow.

[0101] Furthermore, since the axial fan 20 does not have a ring portion 23 inside the bell mouth 30, the outer diameter of the fan due to the blade portion 22 can be maximized inside the ring portion 23 compared to an axial fan in which the ring portion is located inside the bell mouth. In other words, the outdoor unit 100 can maximize the fan diameter in the portion where the axial fan 20 is covered by the bell mouth 30. Therefore, the axial fan 20 can increase the airflow from the fan compared to an axial fan in which the ring portion is located inside the bell mouth.

[0102] The axial flow fan 20 has a downstream portion 20c located inside the bell mouth 30 in the direction of airflow formed by the rotation of the axial flow fan 20, and an upstream portion 20b located outside the bell mouth 30. The ring portion 23 is located inside the housing 10, upstream of the bell mouth 30. In other words, in the axial direction of the rotating shaft RA, the ring portion 23 is provided only on the upstream portion of the blade 22, and not on the entire blade 22. Therefore, compared to an axial flow fan such as Patent Document 1, where the ring portion is provided on the entire blade, the axial flow fan 20 has a smaller area covered by the ring portion 23, which reduces the overall weight of the axial flow fan 20.

[0103] Even if the entire axial flow fan 20 is enlarged in the axial direction of the rotating shaft RA to ensure sufficient airflow, the ring portion 23 is provided only on the upstream side of the blades 22. Therefore, the overall weight of the fan can be reduced compared to an axial flow fan where the ring portion is provided on the entire blade. In other words, even if the fan height of the outdoor unit 100 is increased, the weight increase of the axial flow fan 20 can be kept to a minimum.

[0104] Axial flow fans mounted on top-flow type outdoor units tend to be larger, requiring increased fan strength. The axial flow fan 20 has a cylindrical ring portion 23 integrally formed with each radially outer blade end. Because the axial flow fan 20 has a cylindrical ring portion 23, it can be supported at the outer diameter portion of the fan, thus improving its strength compared to axial flow fans without a ring portion. Even if the entire fan is enlarged in the axial direction of the rotating shaft RA to ensure airflow, the ring portion 23 is provided only on the upstream side of the blades 22, thus minimizing the increase in fan weight while improving strength.

[0105] As described above, the axial flow fan 20 can increase the airflow from the fan in the outdoor unit 100 while keeping the weight increase low. Therefore, the outdoor unit 100 equipped with the axial flow fan 20 can increase the airflow from the axial flow fan 20 while keeping the weight increase low.

[0106] The axial flow fan 20 of the outdoor unit 100 is a semi-open type fan in which the downstream portion 20c is located inside the bell mouth 30 in the direction of airflow formed by the rotation of the axial flow fan 20, and the upstream portion 20b is located outside the bell mouth 30. In a semi-open type axial flow fan, there is a risk of backflow of airflow occurring at the outer peripheral edge of the upstream portion, where air may wrap around to the negative pressure side of the blades. The axial flow fan 20 has a ring portion 23 upstream of the bell mouth 30. As shown in part A of Figure 12, the axial flow fan 20 can prevent backflow of airflow because the ring portion 23 allows the airflow to flow along the axial direction of the rotation axis. Therefore, the outdoor unit 100 can improve fan efficiency compared to an outdoor unit that does not have a ring portion on its axial flow fan.

[0107] Furthermore, the axial flow fan 20 has a ring portion 23 upstream of the bell mouth 30. The axial flow fan 20 can rectify the airflow flowing into the fan by the ring portion 23 and direct the rectified airflow towards the blades. In addition, the axial flow fan 20 can direct the rectified airflow into the bell mouth 30 located downstream of the ring portion 23 by the ring portion 23. Therefore, the outdoor unit 100 can improve fan efficiency compared to an outdoor unit that does not have a ring portion on its axial flow fan. In the outdoor unit 100, because there is no airflow flowing into the axial flow fan 20 from the side by the ring portion 23, the rectified airflow flows into the inlet surface, improving fan efficiency.

[0108] In order to ensure sufficient airflow, the axial flow fan 20 has a ring portion 23 provided only on the upstream side of the blades 22. Therefore, compared to an axial flow fan where the ring portion is provided along the entire length of the blades, the axial flow fan 20 can reduce friction between the inner wall surface 23a of the ring portion 23 and the air. By having the ring portion 23 provided only on the upstream side of the blades 22, the axial flow fan 20 can minimize friction with the air and reduce the load on the fan. Therefore, the outdoor unit 100 can improve fan efficiency compared to an outdoor unit where the axial flow fan does not have a ring portion.

[0109] In the axial flow fan 20, the ring portion 23 is provided only on the upstream side of the blades 22 in order to ensure sufficient airflow. In outdoor units where the ring portion is provided along the entire height of the axial flow fan, a gap is created between the bell mouth and the ring (downstream side), causing a problem in which air at very high speeds leaks out. In the outdoor unit 100, since the ring portion 23 is provided only on a part of the upstream side of the axial flow fan 20, the air leaking through the gap between the ring and the bell mouth is at a relatively low speed, and the deterioration of noise can be minimized.

[0110] Furthermore, as shown in Figures 3 and 12, the bell mouth 30 includes a motor support 40 that supports the motor 50. The motor 50 and the motor support 40 are located downstream of the axial fan 20 in the direction of airflow formed by the rotation of the axial fan 20.

[0111] In typical top-flow type outdoor units, the motor and motor support are located upstream of the axial fan. Therefore, in such top-flow type outdoor units, the motor and other components act as obstacles, leading to pressure loss upstream of the axial fan and turbulence in the airflow entering the axial fan, which easily reduces fan efficiency. In contrast, in the outdoor unit 100 according to Embodiment 1, the motor 50 and motor support 40 are located downstream of the axial fan 20. Therefore, since there are no obstacles at the fan intake, the outdoor unit 100 can suppress pressure loss upstream of the axial fan 20 and turbulence in the airflow entering the axial fan 20. Consequently, the outdoor unit 100 can improve fan efficiency.

[0112] Furthermore, the motor support 40 has a plurality of radial struts 42. The plurality of radial struts 42 are spaced apart from each other in the circumferential direction CD of the rotation axis RA. Each of the plurality of radial struts 42 has a stator vane function and extends in the radial direction RD around the rotation axis RA.

[0113] In typical top-flow type outdoor units, noise tends to increase because the leading edge of the fan blades and the motor support are in close proximity. In contrast, in the outdoor unit 100 of Embodiment 1, even if the trailing edge of the fan blades 22 and the motor support 40 are in close proximity, the motor support 40 has a stator vane function, which suppresses the increase in noise. Furthermore, in the outdoor unit 100, since the motor support 40, which is located downstream of the axial flow fan 20, has a stator vane function, the dynamic pressure boosted by the axial flow fan 20 can be efficiently converted into static pressure, thereby increasing the static pressure efficiency.

[0114] Furthermore, as described above, the outdoor unit 100 of Embodiment 1 has a semi-open axial fan 20 and no motor support on the upstream side of the axial fan 20, which allows for an enlargement of the blades 22 and a miniaturization of the bell mouth 30.

[0115] Furthermore, the motor support 40 has a plurality of circumferential battens 43. Each of the plurality of circumferential battens 43 has a stator vane function and extends in the circumferential direction CD around the rotation axis RA. With this configuration, the outdoor unit 100 can suppress pressure loss upstream of the axial flow fan 20 and turbulence in the airflow flowing into the axial flow fan 20. Therefore, the outdoor unit 100 can improve fan efficiency. In addition, because the motor support 40, which is located downstream of the axial flow fan 20, has a stator vane function, the dynamic pressure boosted by the axial flow fan 20 can be efficiently converted into static pressure, thereby increasing static pressure efficiency.

[0116] Top-flow type outdoor units have a flared bell mouth to allow for static pressure recovery, but this can easily lead to short-cycle airflow. By attaching stator vanes such as radial or circumferential battens 42 or 43 to the outdoor unit 100, the airflow path area can be widened while maintaining straightness, preventing backflow of air and thus improving performance.

[0117] The outdoor unit 100 has at least one heat exchanger 60 that functions as a condenser for condensing the refrigerant or an evaporator for evaporating the refrigerant. The at least one heat exchanger 60 is located inside the housing 10 in a region upstream of the axial fan 20 in the direction of airflow formed by the rotation of the axial fan 20.

[0118] In a semi-open fan, the distance between the fan and the heat exchanger is short, and the fan is shaped to draw in air from the side. As a result, the airflow velocity passing through the heat exchanger increases locally near the fan, which can lead to increased noise. For example, the upper end of the heat exchanger 60 is close to the axial fan 20, which may increase the velocity of the airflow passing through the heat exchanger 60. When the velocity of the airflow passing through the heat exchanger 60 increases, noise may be generated, for example, by the airflow passing between the fins.

[0119] The axial flow fan 20 has a ring portion 23 upstream of the bell mouth 30. As shown in section B of Figure 12, the outdoor unit 100 has a ring portion 23, which prevents airflow from directly flowing into the axial flow fan from the side, thus reducing the localized air velocity passing through the heat exchanger. Because the axial flow fan 20 has a ring portion 23 upstream of the bell mouth 30, the outdoor unit 100, as shown in section B of Figure 12, can suppress the inflow of airflow into the part of the heat exchanger 60 closest to the axial flow fan 20, where the airflow velocity tends to increase relatively easily, thanks to the ring portion 23. Therefore, the outdoor unit 100, with its axial flow fan 20 having a ring portion 23, can reduce the airflow velocity passing through the heat exchanger 60 compared to an outdoor unit without a ring portion.

[0120] Compared to an outdoor unit without a ring, the outdoor unit 100 can reduce the speed of the airflow passing through the heat exchanger 60, thereby reducing the noise generated when the airflow passes through the heat exchanger 60. Furthermore, because the outdoor unit 100 can reduce the speed of the airflow passing through the heat exchanger 60 compared to an outdoor unit without a ring, heat exchange can be performed more efficiently, thereby improving heat exchange performance.

[0121] Furthermore, the axial flow fan 20 has a ring portion 23 upstream of the bell mouth 30. As shown in section B of Figure 12, the ring portion 23 prevents the airflow over the heat exchanger 60, where the airflow velocity is relatively high, from directly flowing into the axial flow fan 20. That is, the airflow over the heat exchanger 60, where the airflow velocity is relatively high, bypasses the ring portion 23 and flows around to the airflow inlet side of the axial flow fan 20. In the outdoor unit 100, the ring portion 23 increases the distance between the heat exchanger 60 and the axial flow fan 20 in the airflow path.

[0122] In the outdoor unit 100, the distance between the heat exchanger 60 and the axial fan 20 is increased, which reduces the airflow velocity passing over the heat exchanger 60. As a result, the airflow velocity passing over the heat exchanger 60 is reduced, and the airflow velocity passing over the heat exchanger 60 becomes more uniform throughout the entire heat exchanger 60.

[0123] Compared to an outdoor unit without a ring section, the outdoor unit 100 can reduce the speed of the airflow passing through the heat exchanger 60, thereby reducing the noise generated when the airflow passes through the heat exchanger 60. Furthermore, compared to an outdoor unit without a ring section, the outdoor unit 100 can reduce the speed of the airflow passing through the heat exchanger 60 and also equalize the airflow velocity throughout the heat exchanger 60, thus enabling more efficient heat exchange and improving heat exchange performance.

[0124] Furthermore, the ring portion 23 has at least one notch 23b that constitutes a missing portion of the wall that makes up the ring portion 23. By having the notch 23b in the ring portion 23 of the axial flow fan 20, the outdoor unit 100 can reduce its weight compared to the case in which the ring portion 23 of the axial flow fan 20 does not have the notch 23b.

[0125] Embodiment 2. Figure 13 is a schematic cross-sectional view of the bell mouth 30 portion showing the internal configuration of the outdoor unit 100 according to Embodiment 2. In Figure 13, the motor 50 is not shown. Embodiment 2 will be described below, but the explanation will be omitted for parts that overlap with Embodiment 1, and the same reference numerals will be used for parts that are the same as or corresponding to those in Embodiment 1. The outdoor unit 100 according to Embodiment 2 specifies the size of the bell mouth 30 and the ring portion 23.

[0126] As shown in Figure 13, in the outdoor unit 100 of Embodiment 2, the ring portion 23 and the bell mouth 30 are formed such that the inner diameter D1 of the ring portion 23 and the inner diameter D2 of the smallest opening diameter portion of the bell mouth 30 are the same size.

[0127] The inner diameter D1 of the ring portion 23 is, for example, the size of the opening diameter at the downstream end portion 23c, which is the downstream end of the ring portion 23 in the axial direction of the rotation axis RA. The inner diameter D2 of the portion of the bell mouth 30 with the smallest opening diameter is, for example, the size of the opening diameter at the intermediate portion 32 of the bell mouth 30. The bell mouth 30 and the ring portion 23 are configured to be continuous by forming the inner diameter D1 of the ring portion 23 and the inner diameter D2 of the portion of the bell mouth 30 with the smallest opening diameter to be the same size.

[0128] In this configuration, the outdoor unit 100 is designed so that the bell mouth 30 and the ring portion 23 are continuous, and the airflow path from the ring portion 23 to the bell mouth 30 is integrated. Therefore, in the outdoor unit 100 of Embodiment 2, the ring portion 23 can perform some of the functions of the bell mouth 30.

[0129] [Effects of the outdoor unit 100] The ring portion 23 and the bell mouth 30 are formed such that the inner diameter D1 of the ring portion 23 and the inner diameter D2 of the smallest opening portion of the bell mouth 30 are the same size. With this configuration, the ring portion 23 together with the bell mouth 30 can have a rectifying function, and the airflow flowing in the direction along the axial direction of the rotating shaft RA passes straight through the axial fan 20. As a result, the fan efficiency of the outdoor unit 100 is improved compared to a unit without this configuration.

[0130] Furthermore, the bell mouth 30 is often made of metal, while the axial fan 20, including the ring portion 23, is often made of resin. When the outdoor unit 100 is made of such materials, the function of straightening the airflow can be improved while reducing weight by having the resin ring portion 23 perform some of the functions of the metal bell mouth 30.

[0131] Embodiment 3. Figure 14 is a top view showing a schematic configuration of the axial flow fan 20 according to Embodiment 3. Figure 15 is a side view showing a schematic configuration of the axial flow fan 20 according to Embodiment 3. Figure 16 is a schematic cross-sectional view of the bell mouth 30 portion showing the internal configuration of the outdoor unit 100 according to Embodiment 3. Figure 14 is a view of the axial flow fan 20 from the air outlet side in the axial direction of the rotating shaft RA, and Figure 15 is a view of the axial flow fan 20 from a direction perpendicular to the rotating shaft RA. In Figure 16, the motor 50 is not shown. Embodiment 3 will be described below, but the description of parts that overlap with Embodiments 1 and 2 will be omitted, and the same reference numerals will be used for parts that are the same as or corresponding to Embodiments 1 and 2.

[0132] As shown in Figures 14 to 16, the axial flow fan 20 is formed such that the upstream portion 23e of the ring portion 23 in the direction of airflow passing through the axial flow fan 20 increases in diameter towards the upstream end 23d, which is the upstream tip. In a cross-section along the radial direction RD of the rotation axis RA and along the axial direction of the rotation axis RA, the downstream portion 23f of the ring portion 23 in the direction of airflow formed by the rotation of the plurality of blades 22 is formed linearly along the axial direction of the rotation axis RA.

[0133] The ring portion 23 is composed of a curved surface in which the diameter of the inner wall surface 23a increases from the downstream side to the upstream tip of the ring portion 23 in the upstream portion 23e of the ring portion 23 in the direction of airflow formed by the rotation of the plurality of blades 22.

[0134] The ring portion 23 has a ring body portion 231 and a ring tip portion 232 that is formed to protrude upstream from the ring body portion 231 in the direction of airflow formed by the rotation of the plurality of blades 22.

[0135] The ring body portion 231 is the downstream portion of the ring portion 23 and is formed, for example, in the shape of a straight tube with a constant opening diameter. When the ring body portion 231 is formed in the shape of a straight tube, the ring body portion 231 is formed in a straight line parallel to the axial direction of the rotation axis RA in a cross-section along the radial direction RD and the axial direction of the rotation axis RA. That is, the ring portion 23 may be formed in a straight line parallel to the rotation axis RA in a cross-section along the radial direction RD and the axial direction of the rotation axis RA, in the downstream portion in the direction of airflow formed by the rotation of the plurality of blades 22. Note that the ring body portion 231 is not limited to a straight tube shape.

[0136] In the radial cross-section of the blade 22, both ends of the ring body 231 in the axial direction of the rotation axis RA are formed parallel to the axial direction of the rotation axis RA. However, the ends of the ring body 231 are not limited to this configuration. For example, the downstream end 23c of the ring body 231, which is the downstream end in the axial direction of the rotation axis RA, may be formed to curve outward.

[0137] The ring tip portion 232 is the upstream portion of the ring portion 23, extending upstream from the ring body portion 231, and is formed such that the tip side widens outward in the radial direction RD of the rotation axis RA and along the axial direction of the rotation axis RA. The ring tip portion 232 is located on the upstream side of the ring portion 23 relative to the ring body portion 231 in the direction of airflow formed by the rotation of the plurality of blades 22, and is formed such that the opening diameter increases from the downstream side of the ring portion 23 toward the upstream tip.

[0138] The ring tip portion 232 is formed in an annular shape along the rotation direction of the axial flow fan 20. The ring tip portion 232 is formed to extend in the axial direction of the rotation axis RA of the axial flow fan 20. The ring tip portion 232 is formed such that the opening diameter gradually increases from the center side to the end side of the axial flow fan 20 in the axial direction of the rotation axis RA. That is, the ring tip portion 232 is formed such that the opening diameter gradually decreases from the end side to the center side of the axial flow fan 20 in the axial direction of the rotation axis RA. The ring portion 23, having the ring tip portion 232, is formed so that one end gradually narrows as it moves in the direction of airflow into the axial flow fan 20.

[0139] As shown in Figure 16, the ring tip portion 232 is formed in a curved shape so that, in a cross-section along the radial direction RD of the rotation axis RA of the axial flow fan 20 and in a cross-section along the axial direction of the rotation axis RA, the tip side widens outward from the radial direction RD relative to the straight rotation axis RA. As shown in Figure 3, when viewed from the radial direction RD which is perpendicular to the rotation axis RA, the ring portion 23 has a curved portion formed on the upstream side in the direction of airflow passing through the axial flow fan 20.

[0140] The ring tip portion 232 is formed in an arc shape in a cross-section along the radial direction RD of the rotation axis RA and along the axial direction of the rotation axis RA, as shown in Figure 16, for example, and the upstream end portion 23d of the ring portion 23 is formed to face outward in the radial direction RD of the rotation axis RA. That is, the inlet of the ring portion 23 faces outward and has a radius (R). Note that the configuration of the upstream end portion 23d of the ring portion is not limited to this configuration. For example, the ring portion 23 and the ring tip portion 232 may be further bent to follow the axial direction of the rotation axis RA, and the upstream end portion 23d may be formed to face downstream.

[0141] The ring portion 23 has a curved tip portion 232 in its cross-sectional shape, and as a result, it has a curved surface portion 23g that forms a curved surface in the upstream portion of the ring portion 23. The inner wall surface 23a of the upstream portion of the ring portion 23 has a curved surface portion 23g in which the diameter increases from the downstream side to the upstream tip of the ring portion 23 in the direction of airflow formed by the rotation of the blade 22. The curved surface portion 23g is the inner wall surface 23a of the ring tip portion 232.

[0142] Figure 17 is a schematic cross-sectional view of the bell mouth 30 portion showing the internal configuration of a modified example of the outdoor unit 100 according to Embodiment 3. In Figure 17, the motor 50 is not shown. The outdoor unit 100 in Figure 17 has a different configuration of the ring tip portion 232 from the configuration of the ring tip portion 232 shown in Figure 16.

[0143] The ring tip 232 is not limited to a curved shape as shown in Figure 16 in a cross-section along the radial direction RD and axial direction of the rotation axis RA. The ring tip 232 may be formed in a straight line inclined with respect to the axial direction of the rotation axis RA in a cross-section along the radial direction RD and axial direction of the rotation axis RA, as shown in Figure 17. In other words, the ring tip 232 may be formed in a flared shape that widens in diameter as it approaches the upstream tip.

[0144] The ring portion 23 shown in Figure 17 is the downstream portion of the ring portion 23 and includes a straight tubular ring body portion 231 and an upstream portion of the ring portion 23 and includes a ring tip portion 232 that extends upstream from the ring body portion 231. The ring tip portion 232 is formed in a flared shape with the tip side widening radially outward, and in a cross section along the radial direction RD of the rotation axis RA and along the axial direction of the rotation axis RA, it is formed in a straight line inclined with respect to the axial direction of the rotation axis RA.

[0145] [Effects of the outdoor unit 100] The ring portion 23 is the downstream portion of the ring portion 23 in the direction of airflow formed by the rotation of the plurality of blades 22, and includes a straight-tube-shaped ring body portion 231. With this configuration, the ring portion 23, together with the bell mouth 30, can have a rectifying function, and the airflow flowing in the direction along the axial direction of the rotation axis RA passes straight through the axial flow fan 20. As a result, the fan efficiency of the outdoor unit 100 is improved compared to a unit without this configuration.

[0146] The ring portion 23 includes a ring tip portion 232 located on the upstream side of the ring portion 23 relative to the ring body portion 231 in the direction of airflow formed by the rotation of the plurality of blades 22. The ring tip portion 232 is formed such that its opening diameter increases from the downstream side to the upstream tip of the ring portion 23. With this configuration, the outdoor unit 100 makes it easier for airflow flowing in from a direction perpendicular to the axial direction of the rotating shaft RA to flow into the axial fan 20, compared to a unit without this configuration.

[0147] The outdoor unit 100 has a heat exchanger 60 positioned on the side of the housing 10, so that the heat exchanger 60 is positioned relatively below and to the side of the axial flow fan 20. As a result, the airflow that has passed through the heat exchanger 60 flows more easily into the axial flow fan 20 with this configuration. Therefore, the fan efficiency of the outdoor unit 100 is improved compared to a unit without this configuration. In addition, the outdoor unit 100 has a ring tip 232, which allows the axial flow fan 20 to be placed on a flat surface in a stable state, making it easier to manage the axial flow fan 20 during storage.

[0148] The ring portion 23 is located on the upstream side of the ring portion 23 and includes a ring tip portion 232 that extends upstream from the ring body portion 231. The ring tip portion 232 is formed in a flared shape with its tip side widening radially outward, and in a cross-section along the radial direction and axial direction of the rotation axis RA, it is formed in a straight line inclined with respect to the axial direction of the rotation axis RA.

[0149] With this configuration, the outdoor unit 100 facilitates the flow of air that has passed through the heat exchanger 60 into the axial fan 20. As a result, the fan efficiency of the outdoor unit 100 is improved compared to a unit without this configuration. Furthermore, because the outdoor unit 100 has a ring tip 232, the axial fan 20 can be placed stably on a flat surface, making it easier to manage the axial fan 20 during storage.

[0150] Figure 18 is a conceptual diagram showing the airflow pattern passing through the ring portion 23 in the case of the outdoor unit 100 according to Embodiment 3. Figure 19 is a conceptual diagram showing the airflow pattern passing through the ring portion 23 in the case of the outdoor unit 100 according to a comparative example. The outdoor unit 100 according to Embodiment 3 differs from the outdoor unit 100 shown in Figure 19 in that the ring portion 23 of the axial flow fan 20 has a ring tip portion 232, as shown in Figure 18. The outdoor unit 100 shown in Figure 19 does not have a ring tip portion 232 on the ring portion 23 of the axial flow fan 20.

[0151] Figure 18 shows an example of the airflow velocity distribution around the ring portion 23 when the ring tip portion 232 is present. Figure 19 shows an example of the airflow velocity distribution around the ring portion 23 when the ring tip portion 232 is absent. In Figures 18 and 19, the darker colored areas indicate high-speed areas where airflow separation may occur.

[0152] As shown in Figure 19, in the case of a ring portion 23 that is formed in a straight tubular shape without a ring tip portion 232, the airflow velocity increases at the upstream end portion 23d, which is the upstream end of the ring portion 23, making airflow separation more likely. When airflow separation occurs, the fan efficiency of the axial flow fan 20 may decrease.

[0153] In the outdoor unit 100 of Embodiment 3, the ring tip portion 232 is formed in an arc shape in a cross section along the radial direction RD of the rotation axis RA and along the axial direction of the rotation axis RA, and the upstream end portion 23d of the ring portion 23 is formed to face outward in the radial direction of the rotation axis RA.

[0154] When the outdoor unit 100 has this configuration, as shown in Figure 18, the decrease in airflow velocity is suppressed at the upstream end 23d of the ring portion 23 compared to the axial flow fan in Figure 18, making airflow separation less likely. Therefore, by having this configuration, the outdoor unit 100 can prevent airflow separation at the inlet portion of the ring portion 23 and improve the fan efficiency of the axial flow fan 20 compared to when it does not have this configuration.

[0155] Furthermore, the ring tip portion 232 of the outdoor unit 100 is formed in an arc shape in a cross section along the radial direction RD of the rotation axis RA and along the axial direction of the rotation axis RA, and the upstream end portion 23d of the ring portion 23 is formed to face outward in the radial direction of the rotation axis RA. With this configuration, the outdoor unit 100 can place the axial flow fan 20 in a stable position on a flat surface, making it easier to manage the axial flow fan 20 during storage.

[0156] Embodiment 4. Figure 20 is a cross-sectional view showing the schematic configuration of the outdoor unit 100 according to Embodiment 4. Figure 20 shows the portion of the outdoor unit 100 where the axial flow fan 20 is located. In Figure 20, the motor 50 is not shown. Also, in Figure 20, the bell mouth 30 and the axial flow fan 20 are shown in a simplified and conceptual manner. The dashed lines extending left and right in Figure 20 indicate the ring portion 23. Embodiment 4 will be described below, but the explanation of parts that overlap with Embodiments 1 to 3 will be omitted, and the same reference numerals will be used for parts that are the same as or corresponding to Embodiments 1 to 3.

[0157] As shown in Figure 20, in the outdoor unit 100 according to Embodiment 4, the axial flow fan 20 is configured as follows. Each of the multiple blades 22 is formed such that the first blade portion 221 connected to the ring portion 23 protrudes radially RD outward from the second blade portion 222 that is not connected to the ring portion 23. The axial flow fan 20 is formed such that the first outer diameter W1 of the fan formed by the first blade portion 221 is larger than the second outer diameter W2 of the fan formed by the second blade portion 222.

[0158] The first outer diameter W1 of the fan formed by the first blade section 221 is the outer diameter of the part of the fan formed by the first blade section 221 that has the smallest outer diameter. The second outer diameter W2 of the fan formed by the second blade section 222 is the outer diameter of the part of the fan formed by the second blade section 222 that has the largest outer diameter. The axial flow fan 20 has an enlarged fan diameter only in the part where the ring section 23 is attached.

[0159] In the outdoor unit 100, it is desirable that the first outer diameter W1 of the fan, which is formed by the first blade portion 221, is the same size as or larger than the inner diameter D2 of the smallest opening portion of the bell mouth 30. The portion that constitutes the inner diameter D2 of the bell mouth 30 is, for example, the intermediate portion 32 of the bell mouth 30. The ring portion 23 is formed, for example, to be located below the top surface portion 16 of the housing 10.

[0160] [Effects of the outdoor unit 100] Each of the multiple blades 22 is formed such that the first blade portion 221 connected to the ring portion 23 protrudes radially RD outward from the outer circumference of the second blade portion 222 which is not connected to the ring portion 23. The axial flow fan 20 is formed such that the first outer diameter W1 formed by the first blade portion 221 is larger than the second outer diameter W2 formed by the second blade portion 222.

[0161] With this configuration, the outdoor unit 100 can increase the outer diameter of the fan at the first blade portion 221. For example, with this configuration, the outdoor unit 100 can make the outer diameter of the fan at the first blade portion 221 larger than the inner diameter of the bell mouth 30. Therefore, by having this configuration, the outdoor unit 100 can increase the blade area of ​​the blade 22 compared to when it does not have this configuration, and improve the airflow from the fan.

[0162] Embodiment 5. Figure 21 is a cross-sectional view showing the schematic configuration of the outdoor unit 100 according to Embodiment 5. Figure 21 shows the portion of the outdoor unit 100 where the axial flow fan 20 is located. In Figure 21, the motor 50 is not shown. Embodiment 5 will be described below, but the description of parts that overlap with Embodiments 1 to 4 will be omitted, and the same reference numerals will be used for the same or corresponding parts as in Embodiments 1 to 4.

[0163] In the outdoor unit 100 according to Embodiment 5, the entire ring portion 23 is formed such that the opening diameter increases from the downstream side to the upstream tip of the ring portion 23 in the direction of airflow formed by the rotation of the plurality of blades 22.

[0164] The ring portion 23 is formed such that the upstream end 23d, which is the upstream end in the axial direction of the rotation axis RA, is located on the outer circumference in the radial direction RD more than the downstream end 23c, which is the downstream end.

[0165] The entire ring portion 23 is formed in a flared shape, with its tip widening radially outward toward the upstream side in the direction of airflow formed by the rotation of the multiple blades 22. The ring portion 23 is formed in a straight line inclined with respect to the axial direction of the rotation axis RA in a cross-section along the radial direction RD of the rotation axis RA and along the axial direction of the rotation axis RA.

[0166] It is desirable that the inner diameter of the downstream end 23c of the ring portion 23 of the outdoor unit 100 is the same as the opening diameter of the upstream end 30b of the bell mouth 30, or smaller than the opening diameter of the upstream end 30b of the bell mouth 30. The upstream end 30b of the bell mouth 30 forms the inlet 30g of the bell mouth 30.

[0167] In other words, it is desirable that the ring portion 23 and the bell mouth 30 are formed such that the size of the inner diameter W3 at the downstream end 23c, which is the downstream end of the ring portion 23, is the same as the size of the opening diameter W4 of the inlet 30g of the bell mouth 30. Alternatively, it is desirable that the ring portion 23 and the bell mouth 30 are formed such that the size of the inner diameter W3 at the downstream end 23c, which is the downstream end of the ring portion 23, is smaller than the size of the opening diameter W4 of the inlet 30g of the bell mouth 30.

[0168] [Effects of the outdoor unit 100] When the ring portion 23 is located below the top surface portion 16 of the housing 10, the airflow passing through the ring portion 23 may collide with the inner wall surface of the housing 10, potentially causing pressure loss. The entire ring portion 23 is formed such that, in the direction of airflow formed by the rotation of the multiple blades 22, the opening diameter of the ring portion 23 increases from the downstream side to the upstream tip.

[0169] In the outdoor unit 100 according to Embodiment 5, the airflow flows along the inner wall surface 23a of the ring portion 23. With this configuration, the airflow flowing on the outer circumference of the axial fan 20 has a vector component that is oriented in the axial direction of the rotation axis RA when viewed in the axial direction of the rotation axis RA. Therefore, even when the ring portion 23 of the outdoor unit 100 is located below the top surface 16 of the housing 10, the airflow that has passed through the ring portion 23 is less likely to collide with the inner wall surface of the housing 10, or is less likely to collide directly with the inner wall surface of the housing 10. With this configuration, the outdoor unit 100 can prevent pressure loss of the airflow by making it less likely for the airflow that has passed through the ring portion 23 to collide with the inner wall surface of the housing 10.

[0170] Furthermore, with this configuration, the airflow that has passed through the heat exchanger 60 in the outdoor unit 100 flows more easily into the axial fan 20. As a result, the fan efficiency of the outdoor unit 100 is improved compared to when this configuration is not present. In addition, because the outdoor unit 100 has the ring portion 23 of this configuration, the axial fan 20 can be placed on a flat surface in a stable state, making it easier to manage the axial fan 20 during storage.

[0171] The entire ring portion 23 is formed in a flared shape, with its tip widening radially outward toward the upstream side in the direction of airflow formed by the rotation of the multiple blades 22. The entire ring portion 23 is formed in a straight line inclined with respect to the axial direction of the rotation axis RA in a cross-section along the radial direction RD of the rotation axis RA and along the axial direction of the rotation axis RA.

[0172] With this configuration, the outdoor unit 100 has a configuration in which the airflow flowing on the outer circumference of the axial fan 20 has a vector component that is oriented in the axial direction of the rotation axis RA when viewed in the axial direction of the rotation axis RA. Therefore, even when the ring portion 23 is located below the top surface portion 16 of the housing 10, the airflow that has passed through the ring portion 23 is less likely to collide with the inner wall surface of the housing 10, or is less likely to collide directly with the inner wall surface of the housing 10. With this configuration, the outdoor unit 100 can prevent pressure loss of the airflow by making it less likely for the airflow that has passed through the ring portion 23 to collide with the inner wall surface of the housing 10.

[0173] Furthermore, with this configuration, the airflow that has passed through the heat exchanger 60 in the outdoor unit 100 flows more easily into the axial fan 20. As a result, the fan efficiency of the outdoor unit 100 is improved compared to when this configuration is not present. In addition, because the outdoor unit 100 has the ring portion 23 of this configuration, the axial fan 20 can be placed on a flat surface in a stable state, making it easier to manage the axial fan 20 during storage.

[0174] Furthermore, the ring portion 23 and the bell mouth 30 are formed such that the inner diameter W3 at the downstream end 23c of the ring portion 23 is the same as the opening diameter W4 of the inlet 30g of the bell mouth 30. Alternatively, the ring portion 23 and the bell mouth 30 are formed such that the inner diameter W3 at the downstream end 23c of the ring portion 23 is smaller than the opening diameter W4 of the inlet 30g of the bell mouth 30.

[0175] The outdoor unit 100, with its configuration, is designed so that the airflow passing through the ring portion 23 is less likely to collide with the inner wall surface of the housing 10, thus reducing pressure loss in the airflow. The outdoor unit 100, with its configuration, is designed so that the ring portion 23 and the bell mouth 30 are connected, allowing the rectified airflow to pass more easily through the axial fan 20, thereby improving fan efficiency.

[0176] Embodiment 6. [Refrigeration Cycle Device 300] Figure 22 is a conceptual diagram showing the configuration of the refrigerant circuit 315 of the refrigeration cycle device 300 according to Embodiment 6. In the following description, the refrigeration cycle device 300 will be described in the case where it is used for air conditioning purposes, but the refrigeration cycle device 300 is not limited to those used for air conditioning purposes. The refrigeration cycle device 300 is used for refrigeration or air conditioning purposes, such as in refrigerators or freezers, vending machines, air conditioning systems, refrigeration systems, water heaters, etc.

[0177] The refrigeration cycle system 300 provides air conditioning by heating or cooling the room by transferring heat between the outside air and the indoor air via a refrigerant. The refrigeration cycle system 300 comprises an outdoor unit 100 and an indoor unit 200 having an indoor heat exchanger 210 and a blower fan 220. Although Figure 1 shows one outdoor unit 100 and one indoor unit 200, there may be multiple outdoor units 100 and indoor units 200.

[0178] The refrigeration cycle device 300 has an indoor unit 200 and an outdoor unit 100 connected by refrigerant piping 311, forming a refrigerant circuit 315 through which the refrigerant circulates. In the refrigerant circuit 315 of the refrigeration cycle device 300, the compressor 110, flow path switching device 120, heat exchanger 60, expansion valve 140, and indoor heat exchanger 210 are sequentially connected via the refrigerant piping 311. Note that the refrigerant circuit 315 shown in Figure 1 is just one example, and other configurations are possible. For example, the refrigeration cycle device 300 does not have a flow path switching device 120, and may have an accumulator (not shown).

[0179] [Indoor unit 200] The indoor unit 200 has an indoor heat exchanger 210 and a blower fan 220. The indoor unit 200 draws indoor air into the indoor unit 200 using the blower fan 220, and the indoor heat exchanger 210 exchanges the heat of the drawn-in air to make it cool or warm. The indoor unit 200 blows out the cool or warm air to the outside of the indoor unit 200 and blows conditioned air into the room.

[0180] The indoor unit 200 performs heat exchange between the refrigerant flowing inside the indoor heat exchanger 210 and the air supplied by the blower fan 220. The indoor heat exchanger 210 adjusts the temperature and humidity of the air that is drawn in from outside the indoor unit 200 and blown out from inside the indoor unit 200 into the air-conditioned space. During heating operation, the indoor heat exchanger 210 functions as a condenser, condensing and liquefying the refrigerant. During cooling operation, the indoor heat exchanger 210 functions as an evaporator, evaporating and vaporizing the refrigerant.

[0181] [Outdoor unit 100] The outdoor unit 100 has a housing 10 with a bell mouth 30, and inside the housing 10 (see Figure 3) there is at least a heat exchanger 60 and an axial fan 20. In Figure 22, the outdoor unit 100 has a compressor 110, a flow path switching device 120, a heat exchanger 60 and an expansion valve 140 in the refrigerant circuit 315. The compressor 110, the flow path switching device 120 and the expansion valve 140, etc. may be located outside the housing 10.

[0182] The compressor 110 compresses and discharges the inhaled refrigerant. The flow path switching device 120 is, for example, a four-way valve, which switches the direction of the refrigerant flow path. The refrigeration cycle device 300 can achieve heating or cooling operation by switching the flow of refrigerant using the flow path switching device 120 based on instructions from a control device (not shown).

[0183] The heat exchanger 60 performs heat exchange between the refrigerant and the outdoor air. During heating operation, the heat exchanger 60 functions as an evaporator, and during cooling operation, it functions as a condenser. The heat exchanger 60 is equipped with an axial flow fan 20, which is a blower, to improve the efficiency of heat exchange between the refrigerant and the outdoor air. The expansion valve 140 is a throttling device (flow rate control means), and functions as an expansion valve by adjusting the flow rate of the refrigerant flowing through the expansion valve 140, and adjusts the pressure of the refrigerant by changing the opening degree.

[0184] The refrigeration cycle device 300 includes one or more outdoor units 100 from any of Embodiments 1 to 5. The refrigeration cycle device 300 according to Embodiment 6 has one or more outdoor units 100 from any of Embodiments 1 to 5, and therefore obtains the same effects as the outdoor units 100 according to Embodiments 1 to 5. The refrigeration cycle device 300 can increase the airflow from, for example, the axial flow fan 20 while keeping the increase in weight low.

[0185] Although the outdoor unit 100 has been described above based on the embodiments, the outdoor unit 100 is not limited to the configuration of the embodiments described above. Each of the embodiments 1 to 6 described above can be combined and implemented. The configuration of the outdoor unit 100 described above is just one example, and it may include other components or omit some components. In short, the outdoor unit 100 includes the range of design changes and application variations that are normally performed by those skilled in the art, without departing from its technical concept.

[0186] 10 Housing, 10a Side, 10b Front, 10b1 Front panel, 10c Side, 10d Rear, 10e Top, 10f Bottom, 10g Partition plate, 11 Intake, 12 Outlet, 13 Bottom, 14 First side, 15 Second side, 16 Top, 17 Fan grill, 18 Air chamber, 19 Machine room, 20 Axial fan, 20b Upstream section, 20c Downstream section, 21 Hub, 22 Blade, 22a Leading edge, 22b Trailing edge, 22c Inner edge, 22d Outer edge, 22da Leading edge outer edge, 22db Trailing edge outer edge, 22e Positive pressure surface, 22f Negative pressure surface, 22g Blade surface, 23 Ring section, 23a Inner wall surface, 23b 23c Notch, downstream end, 23d Upstream end, 23e Upstream section, 23f Downstream section, 23g Curved section, 30 Bell mouth, 30a Opening, 30b Upstream end, 30c Downstream end, 30d Inner wall surface, 30g Inlet, 31 Upstream section, 32 Middle section, 33 Downstream section, 40 Motor support, 40A Motor support, 41 Boss section, 42 Radial brace, 42a Inner circumference end, 42b Outer circumference end, 43 Circumferential brace, 50 Motor, 50A Motor, 50B Rotating shaft, 50a Rotating shaft, 60 Heat exchanger, 100 Outdoor unit, 110 Compressor, 120 Flow path switching device, 140 Expansion valve, 200 Indoor unit, 210 Indoor heat exchanger, 220 Blower fan, 221 First wing section, 222 Second wing section, 231 Ring body section, 232 Ring tip section, 300 Refrigeration cycle device, 311 Refrigerant piping, 315 Refrigerant circuit, AR Arrow, CD Circumferential direction, D1 Inner diameter, D2 Inner diameter, F First direction, R Rotational direction, RA Rotation axis, RD Radial direction, S Space, W1 First outer diameter, W2 Second outer diameter, W3 Inner diameter, W4 Opening diameter, X Arrow, Y Arrow, Z Arrow.

Claims

1. An outdoor unit comprising: a box-shaped housing having an intake port and an outlet port formed therein; and an axial fan disposed inside the housing and rotating to form an airflow, wherein the housing constitutes the outlet and has a cylindrical bell mouth surrounding the outer circumference of the axial fan, the axial fan having a hub that is rotationally driven to form a rotation axis; a plurality of blades formed around the hub and extending radially outward from the hub; and a cylindrical ring portion that is annular when viewed in the axial direction of the rotation axis and is integrally formed with each radially outer blade end of the plurality of blades, wherein the downstream portion of the axial fan in the direction of airflow formed by the rotation of the axial fan is located inside the bell mouth and the upstream portion is located outside the bell mouth, and the ring portion is located inside the housing upstream of the bell mouth.

2. The outdoor unit according to claim 1, wherein the housing further comprises a motor for rotating the axial fan inside the bell mouth, the bell mouth includes a motor support for supporting the motor, the motor and the motor support are provided downstream of the axial fan in the direction of airflow formed by the rotation of the axial fan, the motor support has a plurality of radial struts, the plurality of radial struts are spaced apart from each other in the circumferential direction of the rotation axis, and each of the plurality of radial struts has a stator vane function and extends radially around the rotation axis.

3. The outdoor unit according to claim 2, wherein the motor support has a plurality of circumferential struts, each of which has a stator vane function and extends in the circumferential direction about the rotation axis.

4. An outdoor unit according to any one of claims 1 to 3, further comprising at least one heat exchanger that functions as a condenser for condensing a refrigerant or an evaporator for evaporating the refrigerant, wherein the at least one heat exchanger is located inside the housing in a region upstream of the axial fan in the direction of airflow formed by the rotation of the axial fan.

5. The outdoor unit according to any one of claims 1 to 4, wherein the ring portion has at least one notch that constitutes a missing portion of a part of the wall constituting the ring portion.

6. The outdoor unit according to any one of claims 1 to 5, wherein the ring portion and the bell mouth are formed such that the inner diameter of the ring portion and the inner diameter of the portion of the bell mouth with the smallest opening diameter are the same size.

7. The outdoor unit according to any one of claims 1 to 5, wherein the ring portion is the downstream portion of the ring portion in the direction of airflow formed by the rotation of the plurality of blades, and comprises a ring body portion formed in the shape of a straight tube, and a ring tip portion located on the upstream portion of the ring portion with respect to the ring body portion in the direction of airflow formed by the rotation of the plurality of blades, and is formed such that the opening diameter increases from the downstream side to the upstream tip of the ring portion.

8. The outdoor unit according to claim 7, wherein the tip of the ring is formed in an arc shape in a cross-section along the radial direction and the axial direction of the rotation axis, and the upstream end of the ring is formed to face outward in the radial direction of the rotation axis.

9. The outdoor unit according to any one of claims 1 to 5, wherein the ring portion is the downstream portion of the ring portion in the direction of airflow formed by the rotation of the plurality of blades, and comprises a ring body portion formed in the shape of a straight tube, and a ring tip portion located on the upstream portion of the ring portion, extending upstream from the ring body portion, with its tip portion formed in a flared shape that widens radially outward, and in a cross section along the radial direction and axial direction of the rotation axis, it is formed in a straight line inclined with respect to the axial direction of the rotation axis.

10. The outdoor unit according to any one of claims 1 to 9, wherein each of the plurality of blades is formed such that the first blade portion connected to the ring portion protrudes radially outward from the second blade portion not connected to the ring portion, and the axial flow fan is formed such that the first outer diameter is larger than the second outer diameter when the outer diameter of the fan formed by the first blade portion is defined as the first outer diameter and the outer diameter of the fan formed by the second blade portion is defined as the second outer diameter.

11. The outdoor unit according to any one of claims 1 to 5, wherein the entire ring portion is formed such that the opening diameter increases from the downstream side to the upstream tip of the ring portion in the direction of airflow formed by the rotation of the plurality of blades.

12. The outdoor unit according to claim 11, wherein the entire ring portion is formed in a flared shape with its tip widening radially outward toward the upstream side in the direction of airflow formed by the rotation of the plurality of blades, and in a cross section along the radial direction of the rotation axis and the axial direction of the rotation axis, it is formed in a straight line inclined with respect to the axial direction of the rotation axis.

13. The outdoor unit according to claim 11 or 12, wherein the ring portion and the bell mouth are formed such that the inner diameter at the downstream end, which is the downstream end of the ring portion, is the same as the opening diameter of the inlet of the bell mouth, or is smaller than the opening diameter of the inlet of the bell mouth.

14. A refrigeration cycle device comprising an outdoor unit according to any one of claims 1 to 13, and an indoor unit having an indoor heat exchanger and a blower fan.

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