CEILING-EMBEDDED AIR CONDITIONER

A ceiling-embedded air conditioner includes, a casing, a motor including an output shaft protruding downward, the output shaft being driven to rotate about an axis, a main plate fixed to the output shaft and extending radially outward, a turbofan including an impeller, a heat exchanger passed through by air that is sent from the turbofan. And the main plate includes, a tapered portion, a recess formed to be recessed radially inward from the tapered portion, the recess being defined by a cylindrical plate portion extending along the axis, and a disk plate portion extending radially outward from the upper end of the cylindrical plate portion. And an opening is formed in the cylindrical plate portion, the opening penetrates the cylindrical plate portion in the radial direction, and configured such that a circulation flow that exits from the impeller and flows around above the main plate passes through the opening.

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Description
CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Japanese Patent Application Number 2020-015374 filed on Jan. 31, 2020. The entire contents of the above-identified application are hereby incorporated by reference.

TECHNICAL FIELD

The disclosure relates to a ceiling-embedded air conditioner.

RELATED ART

As an example of an air conditioner, a ceiling-embedded air conditioner is widely used. The ceiling-embedded air conditioner mainly includes a casing embedded in an indoor ceiling, a motor including an output shaft that rotates about an axis extending in a vertical direction, a turbofan, a main plate that fixes the turbofan to the output shaft, and a heat exchanger that surrounds the turbofan. By the rotation of the turbofan, indoor air is taken in from the central portion of the casing, and is supplied indoors as cold air or warm air by passing through the heat exchanger.

As a specific example of such a ceiling-embedded air conditioner, the one described in Japanese Patent Application Laid-Open No. 2000-227231 is known. In this apparatus, the main plate has a conical shape whose diameter increases radially outward as advancing from the lower side to the upper side. Most of the air taken into the casing flows upward along the outer surface of the main plate and is then sent to the radially outer heat exchanger by the turbofan. On the other hand, a part of the air taken into the casing forms a circulation flow that goes around the turbofan from above and flows into the upper side of the main plate. In the apparatus described in Japanese Patent Application Laid-Open No. 2000-227231, this circulation flow is used as air for cooling the motor. The air that has cooled the motor joins the main flow (i.e., the flow along the outer surface of the main plate) again through the opening formed in the main plate.

Here, in the case where the angle at which the main flow and the circulation flow is close to a right angle, a mixing loss occurs between the main flow and the circulation flow. As a result, the performance of the air conditioner may be affected. Therefore, in the apparatus according to Japanese Patent Application Laid-Open No. 2000-227231, a bulging portion for guiding the flow direction of the circulation flow is additionally provided as a new component in the opening of the main plate.

SUMMARY

However, the attachment of the separate component to the main plate as described above leads to a complicated configuration and an increase in the number of components and the number of manufacturing steps. As a result, the manufacturing cost may increase.

The present disclosure has been made to solve the above problems, and an object of the present disclosure is to provide a ceiling-embedded air conditioner having a simpler configuration and further improved performance.

In order to solve the problems described above, there is provided a ceiling-embedded air conditioner including, a casing including a suction port formed in the center of a lower portion of the casing and an outlet port formed around the suction port, a motor provided in the casing and including an output shaft protruding downward, the output shaft being driven to rotate about an axis extending in a vertical direction, a main plate fixed to the output shaft in the casing and extending radially outward of the axis; a turbofan including an impeller attached to a lower surface of the main plate in the casing at intervals in a circumferential direction, the impeller being configured to send air introduced from the suction port radially outward, a heat exchanger provided to surround the turbofan in the casing and passed through by air that is sent from the turbofan and flows toward the outlet port. And the main plate includes, a tapered portion extending to increase in diameter radially outward as advancing upward, a recess formed to be recessed radially inward from the tapered portion over the circumferential direction, the recess being defined by a cylindrical plate portion extending along the axis, and a disk plate portion extending radially outward from the upper end of the cylindrical plate portion. And an opening is formed in the cylindrical plate portion, the opening penetrating the cylindrical plate portion, and configured such that a circulation flow that exits from the impeller and flows around above the main plate passes through the opening.

According to the present disclosure, it is possible to provide a ceiling-embedded air conditioner having a simpler configuration and further improved performance.

BRIEF DESCRIPTION OF DRAWINGS

The disclosure will be described with reference to the accompanying drawings, wherein like numbers reference like elements.

FIG. 1 is a cross-sectional view illustrating a configuration of a ceiling-embedded air conditioner according to an embodiment of the present disclosure.

FIG. 2 is a cross-sectional view illustrating a configuration of a main plate according to an embodiment of the present disclosure.

FIG. 3 is a side view illustrating a configuration of an opening according to an embodiment of the present disclosure.

FIG. 4 is a side view illustrating a modified example of an opening according to an embodiment of the present disclosure.

FIG. 5 is a side view illustrating another modified example of an opening according to an embodiment of the present disclosure.

FIG. 6 is a side view illustrating a further modified example of an opening according to an embodiment of the present disclosure.

 DESCRIPTION OF EMBODIMENTS First Embodiment Configuration of Ceiling-embedded Air Conditioner

Hereinafter, a ceiling-embedded air conditioner 100 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 3. As illustrated in FIG. 1, the ceiling-embedded air conditioner 100 includes a casing 1, a motor 2, a main plate 3, a turbofan 4, a heat exchanger 5, and a bell mouth 6.

The casing 1 is embedded in a ceiling wall C of a building. The casing 1 has a rectangular shape when viewed from below, and is recessed upward to form a space therein. To be specific, the casing 1 includes a panel 1A exposed to the ceiling surface Ca and a box-shaped cabinet 1B provided above the panel 1A. The panel 1A includes a panel body 11, which is a rectangular frame body, and a grill 12, which is a suction port 11A provided at the center of the lower portion. The panel body 11 forms an outlet port 11B around the suction port 11A.

The motor 2 is provided at a central portion of a bottom surface 1S facing downward inside the cabinet 1B. The motor 2 includes a motor body 21 that accommodates a coil, a magnet, or the like, and an output shaft 22 that protrudes vertically downward from the motor body 21. The output shaft 22 is rotationally driven about an axis Ac extending in the vertical direction.

A main plate 3 extending radially outward from the output shaft 22 is fixed to the output shaft 22. The configuration of the main plate 3 will be described later. A turbofan 4 is attached to a lower surface of the main plate 3. The turbofan 4 includes an impeller 41 including a plurality of blades arranged at intervals in a circumferential direction, and a disk-shaped shroud 42 covering the impeller 41 from below. The main plate 3 and the turbofan 4 rotate with the rotation of the output shaft 22, and the air sucked from the suction port 11A is sent outward radially.

An annular heat exchanger 5 surrounding the turbofan 4 is provided radially outside the turbofan 4. The heat exchanger 5 is a part of a refrigerant circuit having a refrigeration cycle. The air (main flow Fm) sent to the heat exchanger 5 by the turbofan 4 exchanges heat with the refrigerant when passing through the heat exchanger 5. Thus, the air flowing out to the outer circumferential side of the heat exchanger 5 becomes cold air or warm air. The air flows downward along the side surface of the cabinet 1B and is supplied into the room from the outlet port 11B.

A bell mouth 6 fixed to an upper portion of the panel body 11 is disposed below the turbofan 4. The bell mouth 6 is provided to guide the air introduced from the suction port 11A and send the air to the turbofan 4. The bell mouth 6 has a conical shape in which the diameter gradually decreases from the lower side toward the upper side.

Configuration of Main Plate

Next, the configuration of the main plate 3 will be described in detail with reference to FIGS. 2 and 3. As illustrated in FIG. 2, the main plate 3 includes a bottom plate portion 31, a lower tapered portion 32, a cylindrical plate portion 33, a disk plate portion 34, an upper tapered portion 35, and an upper plate portion 36, which are integrally connected in this order from the inside to the outside radially.

The bottom plate portion 31 has a circular shape extending radially outward from the outer circumferential surface of the output shaft 22. A lower tapered portion 32 is connected to an outer circumferential edge of the bottom plate portion 31. The lower tapered portion 32, from the lower side to the upper side, extends radially from the inner side to the outer side as advancing from the lower side to the upper side. That is, the lower tapered portion 32 has a conical shape whose diameter gradually increases as advancing upward. An outer circumferential edge of the lower tapered portion 32 is located below the motor body 21.

A cylindrical plate portion 33 is connected to an outer circumferential edge of the lower tapered portion 32. The cylindrical plate portion 33 has a cylindrical shape centered on the axis Ac. That is, the cylindrical plate portion 33 extends along the axis Ac in a cross-sectional view. The cylindrical plate portion 33 is formed with a plurality of openings h penetrating the cylindrical plate portion 33 in the radial direction. As illustrated in FIG. 3, the plurality of openings h are rectangular and are arranged at intervals in the circumferential direction. As illustrated in FIG. 2, the openings h are each formed at a position corresponding to the lower end of the motor body 21 in the vertical direction.

A disk plate portion 34 is connected to an upper end edge of the cylindrical plate portion 33. The disk plate portion 34 extends radially outward from the upper end of the cylindrical plate portion 33. The disk plate portion 34 has an annular shape centered on the axis Ac. The cylindrical plate portion 33 and the disk plate portion 34 intersect at a right angle in a cross-sectional view including the axis Ac. Here, the term “right angle” refers to a substantially right angle, and a design tolerance and a manufacturing error are included in the term “right angle”. That is, it is possible to adopt a configuration in which the cylindrical plate portion 33 and the disk plate portion 34 intersect with each other at a slight obtuse angle. The recess R is defined by the cylindrical plate portion 33 and the disk plate portion 34.

An upper tapered portion 35 is connected to an outer circumferential edge of the disk plate portion 34. Similarly to the lower tapered portion 32, the upper tapered portion 35 extends radially from the inner side to the outer side as advancing from the lower side to the upper side That is, the lower tapered portion 32 has a conical shape whose diameter gradually increases as advancing upward. Preferably, the lower tapered portion 32 and the upper tapered portion 35 are on the same conical surface. An upper plate portion 36 is connected to an outer circumferential edge of the upper tapered portion 35. The upper plate portion 36 has an annular shape extending radially outward from an outer circumferential edge of the upper tapered portion 35. The impeller 41 of the turbofan 4 described above is attached to the lower surfaces of the upper plate portion 36 and the upper tapered portion 35. Note that in FIG. 2, an illustration of the impeller 41 is omitted.

Operational Effects

Next, the operation of the ceiling-embedded air conditioner 100 will be described. To operate the ceiling-embedded air conditioner 100, the motor 2 is first driven. By driving the motor 2, the output shaft 22, the main plate 3, and the turbofan 4 rotate about the axis Ac. As the turbofan 4 rotates, indoor air is taken in through the suction port 11A. The air is sent to the turbofan 4 through the bell mouth 6, and then is pressure-fed radially outward to form a main flow Fm (see FIG. 1 or 2). The main flow Fm flows along the lower surface of the main plate 3. That is, the main flow Fm flows from the inside to the outside radially as advancing from the lower side to the upper side. Most of the main flow Fm exchanges heat with the refrigerant by passing through the heat exchanger 5, and becomes cold air or warm air to be supplied into the room from the outlet port 11B.

On the other hand, a part of the main flow Fm does not flow toward the heat exchanger 5, but flows to go around above the main plate 3, thereby forming a circulation flow Fc. The circulation flow Fc flows toward the inner circumferential side along the upper surface of the main plate 3, and then cool s the motor body 21 by being blown to the motor body 21. The circulation flow Fc that has cooled the motor body 21 flows downward, and then joins the main flow Fm on the lower surface side of the main plate 3 through the openings h formed in the main plate 3.

Here, when the angle at which the main flow Fm and the circulation flow Fc join is close to a right angle, a mixing loss occurs between the main flow Fm and the circulation flow Fc. As a result, the air does not flow smoothly in the casing 1, which may affect the performance of the air conditioner. Therefore, in the present embodiment, the recess R is formed in the main plate 3, and the openings h are formed in the cylindrical plate portion 33 that defines the recess R.

According to the above configuration, the cylindrical plate portion 33 in which the openings h are formed extends along the axis Ac. Thus, the circulation flow Fc is blown radially outward from the openings h. Here, the main flow Fm flows upward as advancing radially outward. Since the circulation flow Fc is blown radially outward, the angle at which the main flow Fm and the circulation flow Fc join together can be reduced. As a result, the mixing loss generated between the main flow Fm and the circulation flow Fc can be reduced. Further, in the above-described configuration, such a reduction in mixing loss can be realized only by forming the recess R in the main plate 3 without increasing the number of components. This makes it possible to improve the performance of the ceiling-embedded air conditioner 100 while suppressing an increase in manufacturing cost.

Other Embodiments

The embodiments of the present disclosure have been described above. Various changes and modifications can be made to the above configuration without departing from the scope of the present disclosure. For example, in the above-described embodiment, an example in which the openings h are rectangular and are arranged at intervals in the circumferential direction has been described. However, it is also possible to adopt the configurations illustrated in FIGS. 4 to 6.

In the example of FIG. 4, the positions of the openings h2 adjacent to each other in the axis Ac direction are different. Further, the circumferential end portions t1 of the openings h2 overlap each other in the vertical direction.

According to the above configuration, the circulation flow Fc can be guided uniformly over the entire region in the circumferential direction. As a result, the pressure loss at the openings h2 can be further reduced. In addition, the above configuration can make it possible to suppress a decrease in strength of the main plate due to the formation of the plurality of openings h2. As a result, the durability of the ceiling-embedded air conditioner 100 can be further improved.

In the example of FIG. 5, the end edges L1 of the openings h3 in the circumferential direction extend in a direction inclined with respect to the axis Ac, and the end edges L1 of the openings h3 adjacent to each other overlap in the vertical direction. With this configuration, the same operational effects as those of the example of FIG. 4 can be obtained.

In the example of FIG. 6, a plurality of openings h4 are arranged at intervals in the circumferential direction to form a row, and a plurality of (two) rows R1 and R2 are provided at intervals in the vertical direction. The positions of the openings h4 in the circumferential direction are different from each other in rows adjacent to each other in the vertical direction. With this configuration as well, it is possible to obtain the same operational effects as those of the examples of FIGS. 4 and 5.

Notes

The ceiling-embedded air conditioner 100 described in each of the embodiments is grasped as follows, for example.

(1) A ceiling-embedded air conditioner 100 according to a first aspect includes, a casing 1 including a suction port 11A formed in the center of a lower portion of the casing 1 and an outlet port 11B formed around the suction port 11A, a motor 2 provided in the casing 1 and including an output shaft 22 protruding downward, the output shaft 22 being driven to rotate about an axis Ac extending in a vertical direction, a main plate 3 fixed to the output shaft 22 in the casing 1 and extending radially outward of the axis Ac, a turbofan 4 including an impeller 41 attached to a lower surface of the main plate 3 in the casing 1 at intervals in a circumferential direction, the impeller 41 being configured to send air introduced from the suction port 11A radially outward, a heat exchanger 5 provided to surround the turbofan 4 in the casing 1, and passed through by air that is sent from the turbofan 4 and flows toward the outlet port 11B. And the main plate 3 includes, a tapered portion 32 and 35 extending to increase in diameter radially outward as advancing upward, and a recess R formed to be recessed radially inward from the tapered portion 32 and 35 over the circumferential direction, the recess R being defined by a cylindrical plate portion 33 extending along the axis Ac and a disk plate portion 34 extending radially outward from the upper end of the cylindrical plate portion 33. And an opening h is formed in the cylindrical plate portion 33, the opening h penetrating the cylindrical plate portion 33 in the radial direction, and configured such that a circulation flow Fc that exits from the impeller 41 and flows around above the main plate 3 passes through the opening.

According to the above configuration, the cylindrical plate portion 33 in which the opening h is formed extends along the axis Ac. Thus, the circulation flow Fc is blown radially outward from the opening h. Here, a main flow Fm flowing upward along the main plate 3 is formed outside the main plate 3. More specifically, the main flow Fm flows upward as advancing radially outward. Since the circulation flow Fc blows out radially outward as described above, the angle at which the main flow Fm and the circulation flow Fc join together can be reduced. As a result, the mixing loss generated between the main flow Fm and the circulation flow Fc can be reduced. Further, in the above-described configuration, such a reduction in mixing loss can be realized only by forming the recess R in the main plate 3 without increasing the number of components. This makes it possible to improve the performance of the ceiling-embedded air conditioner 100 while suppressing an increase in manufacturing cost.

(2) In the ceiling-embedded air conditioner 100 according to a second aspect, a plurality of openings h2 are arranged in the circumferential direction, and the circumferential end portions t1 of the openings h2 adjacent to each other overlap in the vertical direction.

According to the above configuration, the plurality of openings h2 are arranged in the circumferential direction, and the circumferential end portions t1 of the adjacent openings h2 overlap in the vertical direction. Thus, the circulation flow can be guided uniformly over the entire region in the circumferential direction. As a result, the pressure loss at the openings h2 can be further reduced.

(3) In the ceiling-embedded air conditioner 100 according to the third aspect, each of the openings h2 has a rectangular shape, the longitudinal direction of the rectangular shape is in the circumferential direction, and the positions of the openings h2 adjacent to each other in the vertical direction are different from each other.

According to the above configuration, each of the openings h2 has a rectangular shape, and the positions of the adjacent openings h2 in the vertical direction are different from each other. Accordingly, the circulation flow Fc can be guided uniformly over the entire region in the circumferential direction, and a decrease in strength of the main plate 3 due to the formation of the plurality of openings h2 can be suppressed to be small. As a result, the durability of the ceiling-embedded air conditioner 100 can be further improved.

(4) In the ceiling-embedded air conditioner 100 according to a fourth aspect, the end edge L1 in the circumferential direction of each of the openings h3 extends in a direction inclined with respect to the axis Ac, and the end edges L1 of the openings h3 adjacent to each other overlap in the vertical direction.

According to the above configuration, the end edge L1 of each of the openings h3 in the circumferential direction is inclined, and the adjacent end edges L1 overlap each other in the vertical direction. Thus, the circulation flow Fc can be uniformly guided over the entire region in the circumferential direction.

(5) In the ceiling-embedded air conditioner 100 according to a fifth aspect, the plurality of openings h4 are arranged at intervals in the circumferential direction to form rows R1 and R2, the plurality of rows such as R1 and R2 are arranged at intervals in the vertical direction, and the positions of the plurality of openings h4 in the circumferential direction are different between the rows R1 and R2 adjacent in the vertical direction.

According to the above configuration, the plurality of openings h4 are arranged in the circumferential direction and the vertical direction, and the positions of the openings h4 in the circumferential direction are different between the rows R1 and R2 adjacent to each other in the vertical direction. Accordingly, the circulation flow Fc can be guided over the entire region in the circumferential direction uniformly, and a decrease in strength of the main plate 3 due to the formation of the plurality of openings h4 can be suppressed to be small. As a result, the durability of the ceiling-embedded air conditioner 100 can be further improved.

While preferred embodiments of the invention have been described as above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirits of the invention. The scope of the invention, therefore, is to be determined solely by the following claims.

Claims

1. A ceiling-embedded air conditioner, comprising:

a casing including a suction port formed in the center of a lower portion of the casing and an outlet port formed around the suction port;
a motor provided in the casing and including an output shaft protruding downward, the output shaft being driven to rotate about an axis extending in a vertical direction;
a main plate fixed to the output shaft in the casing and extending radially outward of the axis;
a turbofan including an impeller attached to a lower surface of the main plate in the casing at intervals in a circumferential direction, the impeller being configured to send air introduced from the suction port radially outward; and
a heat exchanger provided to surround the turbofan in the casing and passed through by air that is sent from the turbofan and flows toward the outlet port, wherein
the main plate includes
a tapered portion extending to increase in diameter radially outward as advancing upward, and
a recess formed to be recessed radially inward from the tapered portion over the circumferential direction, the recess being defined by a cylindrical plate portion extending along the axis and a disk plate portion extending radially outward from the upper end of the cylindrical plate portion, and
an opening is formed in the cylindrical plate portion, the opening penetrating the cylindrical plate portion in the radial direction, and configured such that a circulation flow that exits from the impeller and flows around above the main plate passes through the opening.

2. The ceiling-embedded air conditioner according to claim 1, wherein

a plurality of the openings are arranged in the circumferential direction, and
the circumferential end portions of the plurality of the openings adjacent to each other overlap in the vertical direction.

3. The ceiling-embedded air conditioner according to claim 1, wherein

each of the plurality of the openings has a rectangular shape, the longitudinal direction of the rectangular shape is in the circumferential direction, and
the positions of the plurality of the openings adjacent to each other in the vertical direction are different from each other.

4. The ceiling-embedded air conditioner according to claim 2, wherein

each of the plurality of the openings has a rectangular shape, the longitudinal direction of the rectangular shape is in the circumferential direction, and
the positions of the plurality of the openings adjacent to each other in the vertical direction are different from each other.

5. The ceiling-embedded air conditioner according to claim 1, wherein

end edges of the plurality of the openings in the circumferential direction extend in a direction inclined with respect to the axis, and
the end edges of the plurality of the openings adjacent to each other overlap in the vertical direction.

6. The ceiling-embedded air conditioner according to claim 2, wherein

end edges of the plurality of the openings in the circumferential direction extend in a direction inclined with respect to the axis, and
the end edges of the plurality of the openings adjacent to each other overlap in the vertical direction.

7. The ceiling-embedded air conditioner according to claim 1, wherein

the plurality of the openings are arranged at intervals in the circumferential direction to form a row, a plurality of rows are arranged at intervals in the vertical direction, and
positions of the plurality of the openings in the circumferential direction are different between the plurality of rows adjacent in the vertical direction.

8. The ceiling-embedded air conditioner according to claim 2, wherein

the plurality of the openings are arranged at intervals in the circumferential direction to form a row, a plurality of rows are arranged at intervals in the vertical direction, and
positions of the plurality of the openings in the circumferential direction are different between the plurality of rows adjacent in the vertical direction.

9. The ceiling-embedded air conditioner according to claim 3, wherein

the plurality of the openings are arranged at intervals in the circumferential direction to form a row, a plurality of rows are arranged at intervals in the vertical direction, and
positions of the plurality of the openings in the circumferential direction are different between the plurality of rows adjacent in the vertical direction.

10. The ceiling-embedded air conditioner according to claim 4, wherein

the plurality of the openings are arranged at intervals in the circumferential direction to form a row, a plurality of rows are arranged at intervals in the vertical direction, and
positions of the plurality of the openings in the circumferential direction are different between the plurality of rows adjacent in the vertical direction.

11. The ceiling-embedded air conditioner according to claim 5, wherein

the plurality of the openings are arranged at intervals in the circumferential direction to form a row, a plurality of rows are arranged at intervals in the vertical direction, and
positions of the plurality of the openings in the circumferential direction are different between the plurality of rows adjacent in the vertical direction.

12. The ceiling-embedded air conditioner according to claim 6, wherein

the plurality of the openings are arranged at intervals in the circumferential direction to form a row, a plurality of rows are arranged at intervals in the vertical direction, and
positions of the plurality of the openings in the circumferential direction are different between the plurality of rows adjacent in the vertical direction.
Patent History
Publication number: 20210239329
Type: Application
Filed: Jan 21, 2021
Publication Date: Aug 5, 2021
Inventors: Chihiro MYOREN (Tokyo), Takanori SHIBATA (Tokyo), Ken SHIMIZU (Tokyo)
Application Number: 17/154,478
Classifications
International Classification: F24F 1/0047 (20060101); F24F 1/0022 (20060101); F24F 1/0011 (20060101); F24F 1/0063 (20060101);