A vane assembly, centrifugal fan and air conditioner

Abstract

The application provides a blade assembly, a centrifugal fan and an air conditioner, the blade assembly is applied to the centrifugal fan, the blade assembly comprises a hub and a fan blade fixed on the outer edge of the hub, one side of the hub provided with the fan blade is a windward surface, a spoiler disc is arranged on the windward surface, the spoiler disc is rotatably arranged on the windward surface, and airflow entering the centrifugal fan can swing the spoiler disc, so that the technical problem of large noise during air outlet of the centrifugal fan in the prior art can be solved.

Description

Technical Field

[0001] This invention belongs to the field of centrifugal fan technology, specifically relating to a blade assembly, a centrifugal fan, and an air conditioner. Background Technology

[0002] Most existing fresh air conditioning systems use centrifugal fan systems as the core of air supply. While their high-speed operation can ensure a large air volume, it is accompanied by problems such as high noise and noticeable wind noise, which affects the user experience. Therefore, there is an urgent need for a fresh air supply solution with optimized structure and lower noise to improve the comfort and practicality of fresh air conditioning systems. Summary of the Invention

[0003] Therefore, the present invention provides a blade assembly, a centrifugal fan, and an air conditioner, which can solve the technical problem of high noise when the centrifugal fan is discharging air in the prior art.

[0004] In a first aspect, the present invention provides a blade assembly applied to a centrifugal fan. The blade assembly includes a hub and a blade fixed on the outer edge of the hub. The side of the hub where the blade is located is the windward side. A baffle is provided on the windward side. The baffle is rotatably disposed on the windward side. The airflow entering the centrifugal fan can cause the baffle to swing.

[0005] In some embodiments, a rotation damper is provided at the rotation center of the hub, and the spoiler is connected to the hub via the rotation damper.

[0006] In some embodiments, the rotary damper is a "spring-friction combination" damper.

[0007] In some embodiments, the spoiler is disc-shaped, the spoiler is concentrically arranged with the wheel hub, and the spoiler has through holes.

[0008] In some embodiments, the through hole is a regular hexagonal hole when projected in the axial direction.

[0009] In some embodiments, the spoiler is provided with a clearance groove, and the fan blade passes through the clearance groove. When the hub remains stationary, the spoiler, under the action of the rotation damper, causes a gap to be formed between the fan blade and the clearance groove.

[0010] In some embodiments, the edge of the hub is provided with an annular groove surrounding the hub, and the edge of the spoiler is provided with an annular plate protruding toward the hub. The annular plate is engaged in the annular groove and can rotate around the center of the hub within the annular groove.

[0011] In some embodiments, the shape of the clearance groove is the same as the shape of the fan blade in the axial projection of the hub.

[0012] In some embodiments, the center of the spoiler disc protrudes away from the wheel hub to form a protrusion.

[0013] In some embodiments, the side of the spoiler facing away from the hub is provided with a guide groove extending in the radial direction of the spoiler. When a clearance groove is provided, one end of the guide groove near the outer edge of the spoiler is located between two adjacent clearance grooves.

[0014] In a second aspect, the present invention provides a centrifugal fan, including a volute and the blade assembly.

[0015] Thirdly, the present invention also provides an air conditioner including the centrifugal fan described above.

[0016] This invention provides a spoiler disc on the windward side of the wheel hub. The spoiler disc disturbs the airflow entering the volute, allowing the airflow to flow evenly and thus reducing airflow noise. Attached Figure Description

[0017] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the blade assembly according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the spoiler disk according to an embodiment of the present invention;

[0020] Figure 3 This is an axial schematic diagram of the spoiler disk according to an embodiment of the present invention;

[0021] Figure 4 This is a radial schematic diagram of the spoiler disk according to an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the wind blades being mounted on the wheel hub according to an embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the centrifugal fan after the removal of the baffle plate in an embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of a centrifugal fan with a baffle plate according to an embodiment of the present invention;

[0025] Figure 8 This is a schematic diagram of the frame structure and filter structure of an embodiment of the present invention;

[0026] Figure 9 This is an external view of the centrifugal fan of this invention when it is equipped with an air inlet component;

[0027] Figure 10 This is a schematic diagram of the vertical and horizontal axes of the spoiler disk in an embodiment of the present invention.

[0028] The attached figures are labeled as follows:

[0029] 1. Hub; 2. Fan blade; 3. Spoiler disc; 301. Through hole; 302. Clearance groove; 303. Protrusion; 4. Rotary damper; 501. Frame structure; 502. Filter structure; 6. Volute. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0032] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0033] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0034] With the widespread use of household air conditioners, indoor air quality has become an increasingly important concern. Traditional air conditioners only circulate and cool or heat indoor air during operation, lacking the introduction of fresh air. This leads to increased indoor carbon dioxide concentration and humidity imbalance, and long-term use can easily cause respiratory diseases and other health problems. To address this issue, fresh air conditioning systems have emerged. They introduce fresh air from the outside, achieving air exchange between indoors and outdoors and effectively improving indoor air quality. However, the sources of noise in fresh air systems are quite complex. Fresh air is introduced through the main outdoor unit via ductwork. The fresh air passes through a filter to remove harmful substances and is then delivered into the main air duct of the air conditioner or a separate fresh air duct by a centrifugal impeller. This relatively long fresh air path presents significant resistance, requiring high centrifugal impeller speeds to achieve the required airflow. While the centrifugal fan system, as the core of the air delivery system, ensures a large airflow through its high-speed operation, it also brings problems such as high noise levels and noticeable wind noise, affecting the user experience.

[0035] To reduce the noise of a fresh air conditioner when supplying fresh air, this invention provides a blade assembly, a centrifugal fan, and an air conditioner, which solves the technical problem of high noise levels when centrifugal fans are discharging air in existing technologies. (See also...) Figure 1-9As shown, the present invention provides a blade assembly applied to a centrifugal fan. The blade assembly includes a hub 1 and a blade 2 fixed on the outer edge of the hub 1. The side of the hub 1 on which the blade 2 is located is the windward side. A baffle 3 is provided on the windward side. The baffle 3 is rotatably disposed on the windward side. The airflow entering the centrifugal fan can cause the baffle 3 to swing.

[0036] This application provides a baffle plate 3 on the windward side. When the centrifugal fan is working, the airflow enters the centrifugal fan and impacts the windward side. By setting the baffle plate 3 on the windward side, the airflow impacts the baffle plate 3 and causes it to swing. The swing of the baffle plate 3 disturbs the airflow, allowing the airflow to flow more evenly in all directions within the centrifugal fan. This avoids the vibration caused by the uneven flow of airflow within the centrifugal fan, and correspondingly avoids the noise generated by such vibration.

[0037] Preferred, such as Figure 6 and Figure 7 As shown, a rotation damper 4 is provided at the rotation center of the hub 1, and the spoiler 3 is connected to the hub 1 via the rotation damper 4.

[0038] By setting a rotary damper 4, the spoiler disk 3 swings relative to the hub 1 within a certain angle range, further increasing the disturbance of the air by the spoiler disk 3 and avoiding excessively large swing frequency and amplitude of the spoiler disk 3, which would result in a relatively large speed difference with the airflow and thus friction noise. In this way, the noise generated by the fan blade 2 assembly during operation is further reduced.

[0039] The "rotational damper 4" of this application refers to a device that reduces kinetic energy by providing resistance, enabling the product to achieve smooth mechanical movement and improving the product's quality and lifespan; the "rotational damper 4" can also make the rotation of the spoiler 3 slower relative to the rotation of the hub 1.

[0040] Preferably, the rotary damper 4 is a "spring-friction combination" damper.

[0041] By setting the "rotational damper 4" as a "spring-friction combination" damper, which consists of a helical spring and friction plates, the friction plate pressure can be finely adjusted via an adjusting bolt.

[0042] When hub 1 stops rotating or when the external force on spoiler 3 is absolutely balanced, spoiler 3 can maintain its position relative to hub 1 under the action of the "spring-friction combination" damper. For example, when hub 1 is stationary, spoiler 3 is in a preset position relative to hub 1. When hub 1 rotates, the airflow blows spoiler 3, causing spoiler 3 to swing relative to hub 1. Under the action of the "spring-friction combination" damper, spoiler 3 rotates at a certain angle relative to hub 1. Since the airflow cannot be absolutely stable, this angle is constantly changing. When hub 1 stops rotating, spoiler 3 stops at the preset position relative to hub 1 again under the action of the "spring-friction combination" damper. That is, starting from the preset position, when the spoiler 3 rotates clockwise relative to the hub 1, the "spring-friction combination" damper can give the spoiler 3 a counter-rotating force. When the spoiler 3 rotates counter-rotating relative to the hub 1, the "spring-friction combination" damper can give the spoiler 3 a force towards clockwise rotation. As long as the spoiler 3 is not in the preset position, the "spring-friction combination" damper will give the spoiler 3 a force to return to the preset position.

[0043] The "spring-friction combination" damper is characterized by a linear relationship between friction and relative rotational speed (the rotational speed of the spoiler disk 3 relative to the hub 1), while the spring force exhibits a quadratic function relationship with displacement. This nonlinear damping characteristic causes the fan blade 2 accessory to rotate out of phase during rotation, with its oscillation frequency creating a phase difference with the impeller's rotational frequency, thus effectively reducing noise. This effectively solves the problem of high noise levels in centrifugal fans during high-speed operation, significantly improving the quietness of the air conditioner's operation.

[0044] This relative motion creates a more uniform airflow at hub 1, effectively suppressing eddy noise.

[0045] Through hands-on testing, the centrifugal fan using the blade 2 assembly of this application showed almost no airflow reduction at the highest speed (2300 rpm), a total noise level reduction of 2.3 dB(A), and an average reduction of 1.2 dB(A) in rotational noise in the low-frequency range, demonstrating good performance.

[0046] Specifically, the effect of the "spring-friction combination" damper on the fan blade 2 and the spoiler disk 3 basically conforms to the formula: Where R REV Y is the rotational speed of the spoiler disk 3. REV The rotational speed of blade 2 is given by Para1-Para3, which are related to the damper performance coefficients and are their design parameters.

[0047] Preferred, such as Figure 2-4 As shown, the spoiler 3 is disc-shaped and is concentrically arranged with the wheel hub 1. The spoiler 3 is provided with a through hole 301.

[0048] By making the spoiler 3 disc-shaped and concentrically positioned with the wheel hub 1, the stability of the spoiler 3 as it rotates with the wheel hub 1 is improved. When airflow enters the centrifugal fan, the airflow impacts the baffle plate 3, forming vortices. The through-holes 301 on the baffle plate 3 serve several purposes: First, they eliminate some of the vortices, reducing the noise generated by them. Second, the noise generated by the airflow collides with the hub 1 through the through-holes 301, and the noise is reflected within the through-holes 301, thus reducing noise. Third, the airflow acting on the inner wall of the through-holes 301 facilitates the swinging (rotation) of the baffle plate 3. Even a small airflow can cause the baffle plate 3 to rotate relative to the hub 1, resulting in relative rotation between the baffle plate and the hub 1. The rotation frequency of the hub 1 and the rotation frequency of the baffle plate 3 form a phase difference, and this relative motion creates a more uniform flow at the hub 1, effectively suppressing vortex noise. Fourth, the through-hole structure 301 physically blocks rotational noise, reducing noise propagation through sound wave interference and energy dissipation.

[0049] The spoiler 3 is designed to block the propagation of noise. Furthermore, a silencing cavity is formed between the spoiler 3 and the wheel hub 1. The silencing cavity not only further blocks the propagation of noise, but also reduces the frictional force when the spoiler 3 rotates relative to the wheel hub 1.

[0050] Preferred, such as Figure 3 As shown, the through hole 301 is a regular hexagonal hole when projected in the axial direction.

[0051] The through hole 301 can be a round hole or a polygonal hole, preferably a regular hexagon. All the through holes 301 can form a honeycomb structure, which helps to increase the number of through holes 301 on the baffle plate 3, thereby reducing the impact and reflection of airflow on the baffle plate 3 and reducing airflow noise.

[0052] Furthermore, in the axial projection, the aperture (when it is a regular hexagon, the aperture is the diameter of the circumcircle of the regular hexagon) is 2% to 5% of the diameter of the fan blade 2. The number of through holes 301 increases arithmetically from the inside to the outside along the diameter direction of the spoiler disk 3. For example, the innermost ring is the first ring, and the number of through holes 301 in the first ring is 10. Then the number of through holes 301 in the second ring is 15, and the number of through holes in the third ring is 20.

[0053] Preferred, such as Figure 2 and Figure 3 As shown, the spoiler disk 3 is provided with a clearance groove 302, and the fan blade 2 passes through the clearance groove 302. When the hub 1 remains stationary, the spoiler disk 3, under the action of the rotation damper 4, causes the fan blade 2 to form a gap with the clearance groove 302.

[0054] By setting the clearance groove 302, when the hub 1 remains stationary, the spoiler disk 3, under the action of the rotation damper 4, creates a gap between the fan blade 2 and the clearance groove 302. This limits the rotation of the spoiler disk 3 by the fan blade 2. When the spoiler disk 3 rotates and the fan blade 2 contacts the side of the clearance groove 302, the spoiler disk 3 stops rotating. In this way, on the one hand, the rotation angle of the spoiler disk 3 is kept within a certain range, thus preventing the spoiler disk from swinging too much in one direction. When the spoiler disk 3 contacts the fan blade 2, the spoiler disk 3 will produce a rebound action, making the swing frequency of the spoiler disk 3 form a preset phase difference with the rotation frequency of the hub 1. This improves the turbulence effect of the spoiler disk 3 on the airflow, improves the uniformity of airflow, and effectively suppresses the noise of gas flow, especially vortex noise. On the other hand, the relatively small swing amplitude of the spoiler disk 3 also avoids damage to the "spring-friction combination" damper due to excessive rotation angle.

[0055] Preferably, the edge of the hub 1 is provided with an annular groove surrounding the hub 1, and the edge of the spoiler 3 is provided with an annular plate protruding towards the hub 1. The annular plate is engaged in the annular groove and can rotate around the center of the hub 1 within the annular groove.

[0056] The edge of the hub 1 is provided with an annular groove, and the spoiler 3 is designed to fit into an annular plate that can be inserted into the annular groove. The annular groove and the annular plate cooperate to enable the spoiler 3 to swing (rotate) stably around the circumference of the hub 1, thus avoiding the airflow velocity from decreasing due to the axial fluctuation of the spoiler 3.

[0057] Preferred, such as Figure 3 As shown, in the projection of the hub 1 in the axial direction, the shape of the relief groove 302 is the same as the shape of the fan blade 2.

[0058] By making the shape of the clearance groove 302 the same as the shape of the fan blade 2, when the spoiler 3 swings and contacts the fan blade 2, the contact area between the spoiler 3 and the fan blade 2 is large, and the contact surface is part of the outline of the fan blade 2. In this way, the interference caused to the fan blade 2 when the spoiler 3 swings and hits the fan blade 2 is reduced.

[0059] Setting of clearance groove 302: Since the airflow channels are formed on the suction surface and pressure surface of the fan blade 2 respectively, the projected area of ​​clearance groove 302 in the axial direction is 1.1 to 1.3 times the projected area of ​​the fan blade 2.

[0060] Preferred, such as Figure 5 and Figure 6 As shown, the middle part of the spoiler 3 protrudes away from the hub 1 to form a protrusion 303.

[0061] By making the middle part of the spoiler 3 protrude away from the hub 1, on the one hand, the middle part of the spoiler 3 protrudes away from the hub 1, making the other side of the spoiler 3 concave, that is, forming a space between the spoiler 3 and the hub 1 to accommodate the rotation damper 4. On the other hand, the middle part of the spoiler 3 guides the airflow entering the volute 6, making the airflow flow faster to all sides, which is beneficial to improving the outlet speed of the centrifugal fan.

[0062] The spoiler 3 has a convex shape in the middle (the other side is concave), and the outer edge of the hub 1 has a water-spraying edge with the aforementioned annular groove.

[0063] Specifically, the design of the central protrusion of the spoiler disk 3 adopts a third-order Bézier curve. On the meridional plane of the spoiler disk 3 (the meridional plane is any plane passing through the rotation axis of the spoiler disk 3), the rotation center is the starting point and the radius is the ending point. Its design parameters are as follows:

[0064] R_T = P1*T3 + P2*T2 + P3*T + P4

[0065] H_T = P5*T3 + P6*T2 + P7*T + P8

[0066] Where P1 to P8 are design parameters, T is the ratio between the current radius and the radius of blade 2, R_T is the abscissa of the cross section, and H_T is the ordinate of the cross section. Figure 10 As shown, (the "current radius" is equivalent to an independent variable, a variable along the diameter direction. T is the ratio between this independent variable and the blade radius, ranging from 0 to 1. The cross-section is the meridional plane, with the horizontal axis as the x-axis and the vertical axis as the y-axis). Rotating its curve around the central axis yields the blade 2 accessory model.

[0067] Preferably, the side of the spoiler 3 facing away from the hub 1 is provided with a guide groove extending in the radial direction of the spoiler 3. When a clearance groove 302 is provided, one end of the guide groove near the outer edge of the spoiler 3 is located between two adjacent clearance grooves 302.

[0068] By setting a guide groove on the baffle plate 3, the guide groove guides the airflow, accelerates the airflow, and thus increases the airflow velocity. One end of the guide groove is located between two adjacent clearance grooves 302, and a fan blade 2 is set in the clearance groove 302, so that the airflow flows between the two adjacent fan blades 2, which helps to reduce the impact of the airflow on the fan blades 2 in the radial direction, thereby reducing the noise generated by the rotation of the blade assembly. Since the airflow velocity along the guide groove is faster, the faster airflow can drive the flow of nearby airflow, especially the part of the airflow flowing through the through hole 301. The airflow velocity after flowing through the through hole 301 is slower, but under the drive of the airflow flowing along the guide groove, it can flow faster, which helps to increase the air volume of the centrifugal fan.

[0069] Furthermore, the flow guide grooves are not connected to the through hole 301. There are multiple flow guide grooves, which extend outward from the center of the baffle plate 3 in a divergent pattern.

[0070] The present invention also provides a centrifugal fan, including a volute 6 and the blade assembly described above.

[0071] The centrifugal fan also includes an air inlet cavity connected to the air inlet of the volute 6. A frame structure 501 is installed within the air inlet cavity, dividing it into a front cavity and a rear cavity. The frame structure 501 contains a filter structure 502 in its center. The filter is typically made of non-woven fabric, ensuring air filtration efficiency while reducing airflow resistance. The rear cavity includes a circular hole, typically less than 300mm in diameter, which serves as a guide (collector) for the inlet of the volute 6, the core component of the fresh air system. This circular hole is rounded to eliminate airflow separation. The front cavity of the air inlet cavity is connected to the outside via a duct. The volute 6 is connected to the air inlet cavity; specifically, it is connected to the cavity formed by the collector. The horizontal cross-section perpendicular to the axis of the volute 6 is typically a spiral or a simplified spiral. The volute 6 has an outlet, which can be connected to the main air duct of a household air conditioner indoor unit or used for airflow delivery via a separate duct. The bottom of the volute 6 is used to fix or connect the fan blade 2 drive motor. The fan blade 2 and the hub 1 form a squirrel cage blade assembly. The hub 1 has a flange structure at its center, which can be adapted to the drive motor.

[0072] The volute 6 is injection molded from metal or engineering plastic.

[0073] The present invention also provides an air conditioner including the centrifugal fan described above.

[0074] This air conditioner is a fresh air conditioner, with a centrifugal fan used to deliver outdoor air into the room. When delivering fresh air, this air conditioner has low vibration, low noise, and a large air volume.

[0075] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A blade assembly applied to a centrifugal fan, the blade assembly comprising a hub (1) and blades (2) fixed to the outer edge of the hub (1), characterized in that, The side of the hub (1) where the fan blade (2) is located is the windward side. A baffle (3) is provided on the windward side. The baffle (3) is rotatably located on the windward side. The airflow entering the centrifugal fan can cause the baffle (3) to swing. A rotation damper (4) is provided at the rotation center of the hub (1), and the spoiler (3) is connected to the hub (1) via the rotation damper (4); by providing the rotation damper (4), the spoiler (3) swings relative to the hub (1) in a certain angle range around the circumferential direction of the hub (1).

2. The blade assembly according to claim 1, characterized in that, The rotary damper (4) is a "spring-friction combination" damper.

3. The blade assembly according to claim 1, characterized in that, The spoiler (3) is disc-shaped and is concentrically arranged with the hub (1). The spoiler (3) has a through hole (301).

4. The blade assembly according to claim 3, characterized in that, In the projection along the axial direction, the through hole (301) is a regular hexagonal hole.

5. The blade assembly according to claim 1, characterized in that, The spoiler (3) is provided with a clearance groove (302), and the fan blade (2) passes through the clearance groove (302). When the hub (1) remains stationary, the spoiler (3) causes the fan blade (2) and the clearance groove (302) to form a gap under the action of the rotation damper (4).

6. The blade assembly according to claim 5, characterized in that, The edge of the hub (1) is provided with an annular groove surrounding the hub (1), and the edge of the spoiler (3) is provided with an annular plate protruding toward the hub (1). The annular plate is inserted into the annular groove and can rotate around the center of the hub (1) within the annular groove.

7. The blade assembly according to claim 5, characterized in that, On the projection of the hub (1) in the axial direction, the shape of the relief groove (302) is the same as the shape of the fan blade (2).

8. The blade assembly according to any one of claims 3-7, characterized in that, The middle part of the spoiler (3) protrudes away from the hub (1) to form a protrusion (303).

9. The blade assembly according to claim 8, characterized in that, The spoiler disc (3) has a guide groove extending in the radial direction along the side facing away from the hub (1). When a clearance groove (302) is provided, one end of the guide groove near the outer edge of the spoiler disc (3) is located between two adjacent clearance grooves (302).

10. A centrifugal fan, characterized in that, Includes the volute (6) and the blade assembly as described in any one of claims 1-9.

11. An air conditioner, characterized in that, Includes the centrifugal fan as described in claim 10.

Images