Centrifugal wind wheel, centrifugal fan and air conditioner

Abstract

The embodiment of the present application provides a centrifugal fan wheel, a centrifugal fan and an air conditioner, wherein the centrifugal fan wheel comprises a plurality of blades and an end plate; a plurality of the blades are surrounded to form a containing space on the side close to the rotation axis of the centrifugal fan wheel; the end plate is arranged at one end of the plurality of blades in the axial direction of the centrifugal fan wheel, and part of the area of the end plate is recessed into the containing space to form a first containing groove, a plurality of heat dissipation holes are arranged on the side wall of the first containing groove, the plurality of heat dissipation holes are arranged at intervals in the circumferential direction with the rotation axis as the center, and at least part of the heat dissipation holes are distributed in a non-equidistant manner. The centrifugal fan wheel can better reduce discrete noise.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and in particular to a centrifugal impeller, a centrifugal fan, and an air conditioner. Background Technology

[0002] In related technologies, air conditioners with fresh air function generally achieve air output by setting up a centrifugal fan. In order to make the structure of the centrifugal fan more compact, one type of centrifugal fan embeds the drive motor into the impeller. At the same time, in order to solve the heat dissipation problem of the drive motor, heat dissipation holes are also provided on the impeller.

[0003] However, when the impeller rotates at high speed, external airflow enters the impeller through the heat dissipation holes, forming a high-speed cutting airflow, which causes abnormal discrete noise to occur in the centrifugal fan during operation. Summary of the Invention

[0004] In view of this, embodiments of this application aim to provide a centrifugal impeller, centrifugal fan, and air conditioner that can reduce discrete noise.

[0005] To achieve the above objectives, one embodiment of this application provides a centrifugal impeller, comprising:

[0006] Multiple blades, with the multiple blades forming an accommodating space on one side near the rotation axis of the centrifugal impeller;

[0007] An end plate is disposed at one end of a plurality of blades along the axial direction of the centrifugal impeller. A portion of the end plate is recessed into the receiving space to form a first receiving groove. A plurality of heat dissipation holes are provided on the side wall of the first receiving groove. The plurality of heat dissipation holes are spaced apart along a circumferential direction centered on the rotation axis, and at least some of the heat dissipation holes are non-equidistantly distributed.

[0008] In one embodiment, the plurality of heat dissipation holes are randomly distributed along the circumferential direction.

[0009] In one embodiment, there is a central angle between two adjacent heat dissipation holes, and each central angle is distributed as a sine function or a cosine function.

[0010] In one embodiment, each of the central angles is modulated to present a sine function distribution or a cosine function distribution.

[0011] In one embodiment, the central angle is distributed according to the following sine function:

[0012] △α k+1 ' = 2πZ -1 +2Asin(sπZ -1 )cos(sα1+2πks Z -1 +πsZ-1 )

[0013] Where, △α k+1 ' represents the central angle, 1≤k≤Z, and k is an integer, Z represents the total number of heat dissipation holes, A represents the phase modulation amount, s represents the number of groups, and α1 is the circumferential arrangement angle of the first equidistant heat dissipation hole among the Z equally spaced equidistant heat dissipation holes.

[0014] In one embodiment, the sinusoidal modulation function used for the sinusoidal modulation is: α k ' = α k +Asin(s×α k ), where α k ' is the circumferential arrangement angle of the heat dissipation holes, α k The circumferential arrangement angle of the equally spaced heat dissipation holes is 1≤k≤Z, where k is an integer, Z represents the total number of heat dissipation holes, and A represents the phase modulation amount.

[0015] In one implementation, Z is greater than or equal to 5 and less than or equal to 47.

[0016] In one embodiment, the wall surfaces on opposite sides of the heat dissipation hole along the circumferential direction are a pressure surface and a suction surface, respectively, and the mounting angle of the pressure surface is greater than or equal to the mounting angle of the suction surface and less than or equal to 45°.

[0017] In one embodiment, each of the heat dissipation holes penetrates the portion of the end plate located around the opening of the first receiving groove.

[0018] Another embodiment of this application provides a centrifugal fan, including a volute, a drive motor, and the centrifugal impeller described above. The centrifugal impeller is disposed inside the volute, the drive motor is drivenly connected to the centrifugal impeller, and at least a portion of the drive motor is located within the first receiving groove.

[0019] In one embodiment, a portion of the volute near the first receiving groove is recessed into the first receiving groove to form a second receiving groove. The bottom wall of the second receiving groove is provided with a motor clearance opening. The bottom wall of the second receiving groove and / or the portion of the volute located around the opening of the second receiving groove is provided with a through hole. The drive motor is installed in the second receiving groove.

[0020] Another embodiment of this application provides an air conditioner, including an air conditioning module and a fresh air module, wherein the fresh air module includes the centrifugal fan described above.

[0021] This application provides a centrifugal impeller, a centrifugal fan, and an air conditioner. The centrifugal impeller has multiple heat dissipation holes spaced apart along a circumferential direction centered on the axis of rotation, and at least some of the heat dissipation holes are not equidistantly distributed. This prevents airflow from periodically passing through the heat dissipation holes, thereby effectively reducing discrete noise. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of an air conditioner according to an embodiment of this application;

[0023] Figure 2 for Figure 1 The diagram shows a partial structural cross-section of an air conditioner. The thick arrows without reference numerals indicate the direction of airflow.

[0024] Figure 3 for Figure 2 The exploded view of the centrifugal fan shown;

[0025] Figure 4 for Figure 2 An exploded view of the centrifugal fan from another perspective;

[0026] Figure 5 for Figure 2 The diagram shows a partial structural schematic of the volute.

[0027] Figure 6 for Figure 2 The diagram shown is a structural schematic of a centrifugal impeller.

[0028] Figure 7 for Figure 6 View from direction A;

[0029] Figure 8 for Figure 6 The figure shows a BB cross-sectional view, where the thick arrows without reference numerals indicate the direction of rotation of the centrifugal impeller.

[0030] Explanation of reference numerals in the attached figures

[0031] 10. Fresh air module; 11. Centrifugal fan; 111. Centrifugal impeller; 1111. Blade; 1112. End plate; 1112a. First receiving groove; 1112b. Heat dissipation hole; 1112c. Pressure surface; 1112d. Suction surface; 112. Volute; 112a. Second receiving groove; 112b. Motor clearance opening; 112c. Through hole; 113. Drive motor; 12. Filter screen; 13. Wet film; 14. Air inlet; 15. Air outlet; 20. Air conditioning module. Detailed Implementation

[0032] One embodiment of this application provides a centrifugal fan 11. Please refer to [link / reference]. Figures 2 to 4The centrifugal fan 11 includes a volute 112, a drive motor 113, and a centrifugal impeller 111.

[0033] Please see Figure 3 , Figures 6 to 8 The centrifugal impeller 111 of this application embodiment includes blades 1111 and end plates 1112. Multiple blades 1111 are arranged to form a receiving space on one side near the rotation axis of the centrifugal impeller 111. The end plate 1112 is disposed at one end of the multiple blades 1111 along the axial direction of the centrifugal impeller 111. A portion of the end plate 1112 is recessed into the receiving space to form a first receiving groove 1112a. Multiple heat dissipation holes 1112b are provided on the sidewall of the first receiving groove 1112a. The multiple heat dissipation holes 1112b are spaced apart along a circumferential direction centered on the rotation axis, and at least some of the heat dissipation holes 1112b are not equidistantly distributed.

[0034] Please continue reading. Figure 2 The centrifugal impeller 111 is disposed inside the volute 112, and the drive motor 113 is drivenly connected to the centrifugal impeller 111, with at least a portion of the drive motor 113 located within the first receiving groove 1112a. That is, the first receiving groove 1112a extends into the interior of the centrifugal impeller 111, and the drive motor 113 extends into the first receiving groove 1112a to form a structure embedded in the centrifugal impeller 111.

[0035] The heat dissipation hole 1112b penetrates the side wall of the first receiving groove 1112a to dissipate heat from the drive motor 113. Specifically, during the rotation of the centrifugal impeller 111, external airflow flows from opposite sides of the centrifugal impeller 111 along the axial direction under the action of the centrifugal impeller 111. Part of the airflow flows into the first receiving groove 1112a, passes through the heat dissipation hole 1112b, enters the interior of the volute 112, and then flows out from the airflow outlet of the volute 112 under the action of the centrifugal impeller 111. Since the drive motor 113 is located in the first receiving groove 1112a, the airflow flowing through the first receiving groove 1112a can dissipate heat from the drive motor 113.

[0036] For example, please refer to Figure 3 , Figure 7 and Figure 8 Each heat dissipation hole 1112b can penetrate the part of the end plate 1112 located on the periphery of the slot opening of the first receiving groove 1112a, thereby improving the heat dissipation effect.

[0037] Multiple heat dissipation holes 1112b are spaced apart along a circumferential direction centered on the rotation axis. This means that there is a certain distance between two adjacent heat dissipation holes 1112b along a circumferential direction centered on the rotation axis. However, the fact that at least some heat dissipation holes 1112b are not equidistantly distributed means that these heat dissipation holes 1112b are not equidistantly distributed along a circumferential direction centered on the rotation axis. At least one of these locations has a distance between two adjacent heat dissipation holes 1112b that is different from the distance between other adjacent heat dissipation holes 1112b.

[0038] In related technologies, the multiple heat dissipation holes on the impeller of a centrifugal fan are generally equidistantly distributed along a circumferential direction centered on the axis of rotation, meaning that the distance between any two adjacent heat dissipation holes is equal. Assuming the number of heat dissipation holes is T and the impeller speed is n, when the centrifugal fan is turned on, the airflow periodically passes through each heat dissipation hole, which can easily generate discrete noise with a frequency of f = n × T / 60.

[0039] In this embodiment, multiple heat dissipation holes 1112b are spaced apart along a circumferential direction centered on the axis of rotation, and at least some of the heat dissipation holes 1112b are not equidistantly distributed, so that airflow will not periodically pass through each heat dissipation hole 1112b, thereby effectively reducing discrete noise.

[0040] In one embodiment, the plurality of heat dissipation holes 1112b can be randomly distributed along the circumferential direction centered on the axis of rotation. That is, the distance between two adjacent heat dissipation holes 1112b can be randomly set, rather than being distributed non-equidistantly according to a certain rule.

[0041] In one embodiment, please refer to Figure 7 There is a central angle between two adjacent heat dissipation holes 1112b (i.e., Figure 7 In the context of △α2', △α3', and △α k+1 Furthermore, the central angles can also be distributed according to a sine function, meaning that all central angles satisfy a sine function relationship. This arrangement makes the distribution of heat dissipation holes 1112b more orderly and also effectively reduces discrete noise.

[0042] For example, the central angle can be distributed according to the following sine function:

[0043] △α k+1 ' = 2πZ -1 +2Asin(sπZ -1 )cos(sα1+2πks Z -1 +πsZ -1 )

[0044] Where, △α k+1' represents the central angle, 1≤k≤Z, and k is an integer, Z represents the total number of heat dissipation holes 1112b, A represents the phase modulation amount, s represents the number of groups, and α1 is the circumferential arrangement angle of the first equidistant heat dissipation hole among the Z equally spaced equidistant heat dissipation holes.

[0045] Specifically, please refer to Figure 7 On the projection plane perpendicular to the rotation axis of the centrifugal impeller 111 ( Figure 7 This is essentially the projection of the centrifugal impeller 111 onto the projection plane. The projection of the rotation axis can be defined as the origin of the coordinate system, o. The center line along the horizontal coordinate is the x-axis, and the center of the vertical coordinate axis is the y-axis. The projection of each heat dissipation hole 1112b has a center line passing through the origin of the coordinate system. The angle between the center lines of two adjacent heat dissipation holes 1112b is the central angle (i.e., △α2', △α3', △α...). k+1 ').

[0046] △α k+1 k and 2πks Z in ' -1 In the above, k refers to the kth heat dissipation hole 1112b among the Z heat dissipation holes 1112b, and Z is the total number of heat dissipation holes 1112b on the centrifugal impeller 111.

[0047] Please see Figure 7 For ease of calculation, the center line of a heat dissipation hole 1112b can be aligned with the y-axis. In a clockwise direction, the heat dissipation hole 1112b closest to the heat dissipation hole 1112b that is aligned with the y-axis is defined as the first heat dissipation hole 1112b. In a clockwise direction, the heat dissipation hole 1112b adjacent to the first heat dissipation hole 1112b is the second heat dissipation hole 1112b, then the third heat dissipation hole 1112b, and so on.

[0048] Since the central angle is the angle between the centerlines of two adjacent heat dissipation holes 1112b, therefore, for △α k+1 When k = 1, Δα k+1 ' is △α2', which is actually the central angle between the second heat dissipation hole 1112b and the first heat dissipation hole 1112b. Similarly, △α3' is actually the central angle between the third heat dissipation hole 1112b and the second heat dissipation hole 1112b, and so on.

[0049] A and s are both constants, and their specific values ​​can be determined according to design requirements.

[0050] The equidistant heat dissipation holes are the heat dissipation holes on the original centrifugal impeller. The original centrifugal impeller is not the centrifugal impeller 111 described in this application, but a prototype of the centrifugal impeller 111 described in this application. Based on the relevant parameters on the original centrifugal impeller, the sine function of the central angle can be calculated.

[0051] The number of equidistant heat dissipation holes on the original centrifugal impeller is the same as the number of heat dissipation holes 1112b on the centrifugal impeller 111 described in this application. The equidistant heat dissipation holes are equidistantly distributed on the original centrifugal impeller along a circumferential direction centered on the rotation axis of the original centrifugal impeller. That is to say, the distance between any two adjacent equidistant heat dissipation holes is equal.

[0052] Figure 7 The angle between the centerline of any heat dissipation hole 1112b and the y-axis is the circumferential arrangement angle of that heat dissipation hole 1112b (i.e., Figure 7 α1′, α2′, α3′, α in k For example, the circumferential arrangement angle α2' is the angle between the center line of the second heat dissipation hole 1112b and the y-axis.

[0053] Correspondingly, α1 is the circumferential arrangement angle of the first equidistant heat dissipation hole in the equidistant heat dissipation holes 1112b on the original centrifugal impeller (equivalent to...). Figure 7 (α1' in the text).

[0054] For example, the sinusoidal modulation function used for sinusoidal modulation can be: α k ' = α k +Asin(s×α k ), where α k ' is the circumferential arrangement angle of heat dissipation hole 1112b, α k The circumferential arrangement angle of equally spaced heat dissipation holes.

[0055] Both the phase modulation amount A and the number of components s are constants, and their specific values ​​can be determined according to design requirements.

[0056] For example, 2πZ can be set. -1 -0.0873 < △α k+1 '<2πZ -1 +0.0873, then,

[0057] │A│<0.04365│sin(πs Z -1 )cos(sα1+2πksZ -1 +πsZ -1 )│ -1

[0058] In addition, the total number Z of heat dissipation holes 1112b can also be determined according to design requirements. Preferably, Z can be greater than or equal to 5 and less than or equal to 47.

[0059] In one embodiment, please refer to Figure 8The walls on opposite sides of the heat dissipation hole 1112b along the circumferential direction are the pressure surface 1112c and the suction surface 1112d, respectively. The mounting angle β of the pressure surface 1112c can be greater than or equal to the mounting angle θ of the suction surface 1112d, and less than or equal to 45°.

[0060] Please see Figure 8 On the projection plane perpendicular to the rotation axis of the centrifugal impeller 111 ( Figure 8 (Equivalent to the projection of the cross-section of the centrifugal impeller 111 onto the projection plane). A reference circle Ck can be drawn with the projection of the rotation axis as the center. This reference circle Ck intersects the projections of the pressure surface 1112c and the suction surface 1112d. A tangent line Q1 tangent to the reference circle Ck can be drawn with the intersection of the projection of the pressure surface 1112c and the reference circle Ck as the tangent point. The angle between this tangent line Q1 and the projection of the pressure surface 1112c is the installation angle β of the pressure surface 1112c. Similarly, a tangent line Q2 tangent to the reference circle Ck can be drawn with the intersection of the projection of the suction surface 1112d and the reference circle Ck as the tangent point. The angle between this tangent line Q2 and the projection of the suction surface 1112d is the installation angle θ of the suction surface 1112d, where θ ≤ β ≤ 45°. This configuration can effectively increase the air volume, thereby improving the air output effect of the centrifugal impeller 111.

[0061] Preferably, the installation angle θ of the suction surface 1112d can be greater than or equal to 20°, that is, 20°≤θ≤β≤45°.

[0062] In one embodiment, please refer to Figures 2 to 5 A portion of the volute 112 near the first receiving groove 1112a is recessed into the first receiving groove 1112a to form a second receiving groove 112a. The bottom wall of the second receiving groove 112a is provided with a motor clearance opening 112b. The bottom wall of the second receiving groove 112a and / or the portion of the volute 112 located around the opening of the second receiving groove 112a is provided with a through hole 112c. The drive motor 113 is installed in the second receiving groove 112a.

[0063] In other words, the drive motor 113 can be installed in the second receiving groove 112a so that at least a portion of the drive motor 113 can be located in the first receiving groove 1112a.

[0064] The motor clearance port 112b is used to avoid the drive shaft of the drive motor 113. In other words, the drive shaft of the drive motor 113 can be driven to connect with the centrifugal impeller 111 through the motor clearance port 112b.

[0065] Figure 4 and Figure 5The bottom wall of the second receiving groove 112a and the part of the volute 112 located on the periphery of the groove opening of the second receiving groove 112a are respectively provided with through holes 112c. The through holes 112c can be used for driving the motor 113 to pass wires and for heat dissipation.

[0066] In some embodiments, a through hole 112c may be provided only on the bottom wall of the second receiving groove 112a, or a through hole 112c may be provided only on the part of the volute 112 located on the periphery of the opening of the second receiving groove 112a.

[0067] Another embodiment of this application also provides an air conditioner; please refer to [link / reference needed]. Figure 1 and Figure 2 The air conditioner includes an air conditioning module 20 and a fresh air module 10, wherein the fresh air module 10 includes a centrifugal fan 11 provided in any embodiment of this application.

[0068] The air conditioning module 20 is mainly used to realize the conventional air conditioning adjustment functions of the air conditioner, such as cooling and heating.

[0069] The fresh air module 10 is mainly used to realize the fresh air function.

[0070] For example, please refer to Figure 2 The fresh air module 10 may be equipped with a filter 12, which may include, but is not limited to, a HEPA (High Efficiency Particulate Air Filter) filter. The filter 12 is positioned between the air inlet 14 of the fresh air module 10 and the centrifugal fan 11, wherein the drive motor 113 of the centrifugal fan 11 is located on the side of the centrifugal fan 11 away from the filter 12.

[0071] When the fresh air function is turned on, fresh air from the outdoor environment enters the fresh air module 10 through the air inlet 14 via the fresh air duct. Under the action of the centrifugal impeller 111, the fresh air passes through the filter screen 12 and enters the volute 112 from the side opposite to the drive motor 113. A portion of the airflow enters the volute 112 from the heat dissipation holes 1112b on the periphery of the drive motor 113. The fresh air and airflow entering the volute 112 finally flow into the indoor environment from the air outlet 15 of the fresh air module 10.

[0072] For example, please refer to Figure 2 The fresh air module 10 can be equipped with a wet membrane 13, which mainly plays a humidifying role. The wet membrane 13 can be set between the filter screen 12 and the centrifugal fan 111. The fresh air passes through the filter screen 12 and then passes through the wet membrane 13 for humidification.

[0073] In addition to the fresh air function, the fresh air module 10 can also be set to an internal circulation function. The internal circulation function mainly circulates the airflow in the indoor environment. In other words, the internal circulation function only circulates the airflow in the indoor environment without introducing fresh air from the outdoor environment.

[0074] The fresh air module 10 can be additionally equipped with an internal circulation inlet (not shown in the figure). When the internal circulation function is turned on, the internal circulation inlet is opened and the air inlet 14 is closed. Part of the airflow enters the fresh air module 10 from the internal circulation inlet. Under the action of the centrifugal impeller 111, the airflow entering from the internal circulation inlet passes through the filter screen 12 (if a wet film 13 is provided, the airflow passes through both the filter screen 12 and the wet film 13), and enters the volute 112 from the side opposite to the drive motor 113. Another part of the airflow enters the volute 112 from the heat dissipation hole 1112b on the periphery of the drive motor 113. The fresh air and airflow entering the volute 112 finally flow into the indoor environment from the air outlet 15 of the fresh air module 10.

[0075] Since the centrifugal fan 11 in this embodiment has a good noise reduction effect, the noise of the centrifugal fan 11 is low when the fresh air function or the internal circulation function is turned on, thereby providing users with a comfortable and quiet environment.

[0076] In the description of this application, the references to terms such as "in one embodiment," "in some embodiments," "in other embodiments," "in yet another embodiment," or "exemplary," etc., refer to specific features, areas, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, areas, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine the different embodiments or examples described in this application, as well as the features of the different embodiments or examples.

[0077] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A centrifugal impeller, characterized in that, include: Multiple blades, with the multiple blades forming an accommodating space on one side near the rotation axis of the centrifugal impeller; An end plate is disposed at one end of a plurality of blades along the axial direction of the centrifugal impeller. A portion of the end plate is recessed into the receiving space to form a first receiving groove. A plurality of heat dissipation holes are provided on the side wall of the first receiving groove. The plurality of heat dissipation holes are spaced apart along a circumferential direction centered on the rotation axis, and at least some of the heat dissipation holes are non-equidistantly distributed. The walls on opposite sides of the heat dissipation hole along the circumferential direction are respectively a pressure surface and a suction surface. The installation angle of the pressure surface is greater than or equal to the installation angle of the suction surface and less than or equal to 45°. Specifically, on a projection plane perpendicular to the rotation axis of the centrifugal impeller, a reference circle Ck is drawn with the projection of the rotation axis as its center, intersecting the projections of the pressure surface and the suction surface respectively. A tangent line Q1 is drawn with the intersection of the pressure surface projection and the reference circle Ck as its tangent point, and the angle between the tangent line Q1 and the projection of the pressure surface is the installation angle of the pressure surface. Similarly, a tangent line Q2 is drawn with the intersection of the suction surface projection and the reference circle Ck as its tangent point, and the angle between the tangent line Q2 and the projection of the suction surface is the installation angle of the suction surface.

2. The centrifugal impeller according to claim 1, characterized in that, The plurality of heat dissipation holes are randomly distributed along the circumferential direction.

3. The centrifugal impeller according to claim 1, characterized in that, There is a central angle between two adjacent heat dissipation holes, and each central angle is distributed as a sine function or a cosine function.

4. The centrifugal impeller according to claim 3, characterized in that, Each of the central angles is modulated to present a sine function distribution or a cosine function distribution.

5. The centrifugal impeller according to claim 4, characterized in that, The central angle is distributed according to the following sine function: △α k+1 '=2πZ -1 +2Asin(sπZ -1 )cos(sα1+2πks Z -1 +πsZ -1 ) Where, △α k+1 ' represents the central angle, 1≤k≤Z, and k is an integer, Z represents the total number of heat dissipation holes, A represents the phase modulation amount, s represents the number of groups, and α1 is the circumferential arrangement angle of the first equidistant heat dissipation hole among the Z equally spaced equidistant heat dissipation holes.

6. The centrifugal impeller according to claim 4, characterized in that, The sine modulation function used to make each of the central angles follow the sine function distribution is: α k '=α k +Asin(s×α k ), where α k ' is the circumferential arrangement angle of the heat dissipation holes, α k The circumferential arrangement angle of the equally spaced heat dissipation holes is 1≤k≤Z, where k is an integer, Z represents the total number of heat dissipation holes, and A represents the phase modulation amount.

7. The centrifugal impeller according to claim 5 or 6, characterized in that, Z is greater than or equal to 5 and less than or equal to 47.

8. The centrifugal impeller according to any one of claims 1-6, characterized in that, Each of the heat dissipation holes penetrates the portion of the end plate located around the opening of the first receiving groove.

9. A centrifugal fan, characterized in that, The device includes a volute, a drive motor, and a centrifugal impeller as described in any one of claims 1-8, wherein the centrifugal impeller is disposed within the volute, the drive motor is drivenly connected to the centrifugal impeller, and at least a portion of the drive motor is located within the first receiving groove.

10. The centrifugal fan according to claim 9, characterized in that, A portion of the volute near the first receiving groove is recessed into the first receiving groove to form a second receiving groove. The bottom wall of the second receiving groove is provided with a motor clearance opening. The bottom wall of the second receiving groove and / or the portion of the volute located around the opening of the second receiving groove is provided with a through hole. The drive motor is installed in the second receiving groove.

11. An air conditioner, characterized in that, It includes an air conditioning module and a fresh air module, wherein the fresh air module includes the centrifugal fan as described in claim 9 or 10.

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