Centrifugal wind wheel, centrifugal fan and air conditioner

Abstract

The embodiment of the invention provides a centrifugal wind wheel, a centrifugal fan and an air conditioner, and the centrifugal wind wheel comprises a plurality of blades and an end plate; a containing space is defined by the sides, close to the rotating axis of the centrifugal wind wheel, of the multiple blades. The end plate is arranged at the ends, in the axial direction of the centrifugal wind wheel, of the multiple blades, part of the area of the end plate is sunken towards the interior of the containing space to form a first containing groove, a plurality of heat dissipation holes are formed in the side wall of the first containing groove, the heat dissipation holes are formed in the circumferential direction with the rotation axis as the center at intervals, and the heat dissipation holes are formed in the side wall of the first containing groove. And at least part of the heat dissipation holes are distributed in a non-equidistant manner. According to the centrifugal wind wheel, discrete noise can be well reduced.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioning, and in particular to a centrifugal fan, a centrifugal fan and an air conditioner. Background Art

[0002] In the related art, air conditioners with fresh air function generally achieve air discharge by setting a centrifugal fan. In order to make the structure of the centrifugal fan more compact, there is a centrifugal fan in which the drive motor is embedded in the wind wheel. At the same time, in order to solve the heat dissipation problem of the drive motor, a heat dissipation hole is also set on the wind wheel.

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

[0004] In view of this, the embodiments of the present application hope to provide a centrifugal wind wheel, a centrifugal fan and an air conditioner that can reduce discrete noise.

[0005] To achieve the above object, an embodiment of the present application provides a centrifugal wind wheel, comprising:

[0006] A plurality of blades, wherein a receiving space is formed on one side of the plurality of blades close to the rotation axis of the centrifugal wind wheel;

[0007] An end plate, wherein the end plate is arranged at one end of the plurality of blades along the axial direction of the centrifugal wind wheel, a partial area of ​​the end plate is recessed into the accommodating space to form a first accommodating groove, a plurality of heat dissipation holes are arranged on the side wall of the first accommodating groove, and the plurality of heat dissipation holes are arranged at intervals along the circumferential direction centered on the rotation axis, and at least some of the heat dissipation holes are distributed in non-equidistant directions.

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

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

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

[0011] In one implementation, the center angle is distributed according to the following sinusoidal function:

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

[0013] Among them, △α k+1 ' represents the center angle, 1≤k≤Z, and k is an integer, Z represents the total number of the heat dissipation holes, A represents the phase modulation amount, s represents the number of components, and α1 is the circumferential arrangement angle of the first equidistant heat dissipation hole among the Z equidistant heat dissipation holes distributed at equal intervals.

[0014] In one implementation, the sinusoidal modulation function used for the sinusoidal modulation is: k ' = α k +Asin(s×α k ), where α k ' is the circumferential arrangement angle of the heat dissipation holes, α k is the circumferential arrangement angle of the equally spaced heat dissipation holes, 1≤k≤Z, and k is an integer, Z represents the total number of the 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 respectively a pressure surface and a suction surface, and an installation angle of the pressure surface is greater than or equal to an installation angle of the suction surface and less than or equal to 45°.

[0017] In one embodiment, each of the heat dissipation holes passes through a portion of the end plate located on a peripheral side of a notch of the first accommodating groove.

[0018] Another embodiment of the present application provides a centrifugal fan, including a volute, a drive motor and the centrifugal wind wheel described above, the centrifugal wind wheel is arranged in the volute, the drive motor is drivingly connected to the centrifugal wind wheel, and at least a part of the drive motor is located in the first accommodating groove.

[0019] In one embodiment, a partial area of ​​the volute near the first accommodating groove is recessed into the first accommodating groove to form a second accommodating groove, the bottom wall of the second accommodating groove is provided with a motor avoidance opening, the bottom wall of the second accommodating groove and / or the portion of the volute located on the peripheral side of the groove opening of the second accommodating groove are provided with through holes, and the drive motor is installed in the second accommodating groove.

[0020] Yet another embodiment of the present application provides an air conditioner, comprising an air conditioning module and a fresh air module, wherein the fresh air module comprises the centrifugal fan described above.

[0021] The embodiments of the present application provide a centrifugal fan, a centrifugal blower and an air conditioner, wherein the centrifugal fan wheel has a plurality of heat dissipation holes spaced apart in a circumferential direction centered on a rotation axis, and at least some of the heat dissipation holes are distributed non-equidistantly, thereby preventing the airflow from passing through the heat dissipation holes periodically, thereby effectively reducing discrete noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of an air conditioner according to an embodiment of the present application;

[0023] Figure 2 for Figure 1 A cross-sectional view of a partial structure of an air conditioner shown in FIG. 1 , wherein a thick arrow without a reference numeral indicates the direction of air flow;

[0024] Figure 3 for Figure 2 An exploded view of a centrifugal fan is shown;

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

[0026] Figure 5 for Figure 2 A schematic diagram of a partial structure of a volute shown;

[0027] Figure 6 for Figure 2 The structural schematic diagram of the centrifugal wind wheel shown;

[0028] Figure 7 for Figure 6 A-direction view;

[0029] Figure 8 for Figure 6 The thick arrow without a reference mark in the figure indicates the direction of rotation of the centrifugal wind wheel.

[0030] Description of Reference Numerals

[0031] 10. Fresh air module; 11. Centrifugal fan; 111. Centrifugal wind wheel; 1111. Blades; 1112. End plate; 1112a. First receiving slot; 1112b. Heat dissipation hole; 1112c. Pressure surface; 1112d. Suction surface; 112. Volute; 112a. Second receiving slot; 112b. Motor avoidance port; 112c. Through hole; 113. Drive motor; 12. Filter; 13. Wet film; 14. Air inlet; 15. Air outlet; 20. Air conditioning module. DETAILED DESCRIPTION

[0032] An embodiment of the present application provides a centrifugal fan 11, see Figures 2 to 4The centrifugal fan 11 includes a volute 112 , a drive motor 113 and a centrifugal fan wheel 111 .

[0033] See also Figure 3 , Figures 6 to 8 The centrifugal wind wheel 111 of the embodiment of the present application includes blades 1111 and an end plate 1112. There are multiple blades 1111, and a receiving space is surrounded by multiple blades 1111 on one side close to the rotation axis of the centrifugal wind wheel 111. The end plate 1112 is arranged at one end of the multiple blades 1111 along the axial direction of the centrifugal wind wheel 111, and a part of the end plate 1112 is recessed into the receiving space to form a first receiving groove 1112a. A plurality of heat dissipation holes 1112b are arranged on the side wall of the first receiving groove 1112a, and the plurality of heat dissipation holes 1112b are arranged at intervals along the circumferential direction centered on the rotation axis, and at least part of the heat dissipation holes 1112b are distributed at non-equidistant intervals.

[0034] Please continue reading Figure 2 The centrifugal wind wheel 111 is arranged in the volute 112, the driving motor 113 is drivingly connected to the centrifugal wind wheel 111, and at least a part of the driving motor 113 is located in the first receiving groove 1112a. In other words, the first receiving groove 1112a extends into the interior of the centrifugal wind wheel 111, and the driving motor 113 extends into the first receiving groove 1112a to form a structure embedded in the centrifugal wind wheel 111.

[0035] The heat dissipation hole 1112b penetrates the side wall of the first receiving groove 1112a to dissipate heat for the drive motor 113. Specifically, during the rotation of the centrifugal wind wheel 111, the external airflow flows to the centrifugal wind wheel 111 from the opposite sides of the centrifugal wind wheel 111 along the axial direction under the action of the centrifugal wind wheel 111, wherein part of the airflow flows into the first receiving groove 1112a, passes through the heat dissipation hole 1112b and 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 wind wheel 111. Since the drive motor 113 is arranged at the first receiving groove 1112a, the airflow flowing through the first receiving groove 1112a can dissipate heat for the drive motor 113.

[0036] For example, see Figure 3 , Figure 7 and Figure 8 Each heat dissipation hole 1112b can respectively penetrate the portion of the end plate 1112 located on the peripheral side of the notch of the first receiving groove 1112a, thereby improving the heat dissipation effect.

[0037] A plurality of heat dissipation holes 1112b are arranged at intervals along the circumferential direction with the rotation axis as the center, which is equivalent to that there is a certain distance between two adjacent heat dissipation holes 1112b along the circumferential direction with the rotation axis as the center, and at least some of the heat dissipation holes 1112b are non-equidistantly distributed, which means that these heat dissipation holes 1112b are not equidistantly distributed along the circumferential direction with the rotation axis as the center, and the distance between at least one of the two adjacent heat dissipation holes 1112b is different from the distance between other two adjacent heat dissipation holes 1112b.

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

[0039] In the embodiment of the present application, a plurality of heat dissipation holes 1112b are spaced apart in a circumferential direction centered on the rotation axis, and at least some of the heat dissipation holes 1112b are non-equidistantly distributed, so that the airflow does not periodically pass through the heat dissipation holes 1112b, thereby effectively reducing discrete noise.

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

[0041] In one embodiment, please refer to Figure 7 , there is a central angle (i.e. Figure 7 △α2', △α3', △α k+1 '), each central angle can also be distributed in a sinusoidal function, that is, all the central angles satisfy the relationship of the sinusoidal function. This arrangement can make the distribution of the heat dissipation holes 1112b more orderly and have a better effect of reducing discrete noise.

[0042] Exemplarily, the central angle may be distributed according to the following sinusoidal function:

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

[0044] Among them, △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 components, and α1 is the circumferential arrangement angle of the first equidistant heat dissipation hole among the Z equidistant heat dissipation holes distributed at equal intervals.

[0045] Specifically, see Figure 7 , on the projection plane perpendicular to the rotation axis of the centrifugal wind wheel 111 ( Figure 7 The projection of the rotation axis can be defined as the origin o of the coordinate system, the center line along the horizontal coordinate change is the x-axis, and the center of the coordinate axis along the vertical change 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 in ' and 2πks Z -1 The k in refers to the kth heat dissipation hole 1112b among the Z heat dissipation holes 1112b, and Z is the number of all heat dissipation holes 1112b on the centrifugal wind wheel 111.

[0047] See also Figure 7 For the convenience of calculation, the center line of a heat dissipation hole 1112b can be coincident with the y-axis. In the clockwise direction, the heat dissipation hole 1112b closest to the heat dissipation hole 1112b coincident with the y-axis is defined as the first heat dissipation hole 1112b. In the clockwise direction, the heat dissipation hole 1112b adjacent to the first heat dissipation hole 1112b is the second heat dissipation hole 1112b, followed by the third heat dissipation hole 1112b, and so on.

[0048] Since the central angle is the angle between the center lines of two adjacent heat dissipation holes 1112b, for Δα k+1 ', when k = 1, △α k+1 ' is △α2', △α2' is actually the center angle between the second heat dissipation hole 1112b and the first heat dissipation hole 1112b. Similarly, △α3' is actually the center 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 the specific values ​​of A and s can be determined according to design requirements.

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

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

[0052] Figure 7 The angle between the center line of any heat dissipation hole 1112b and the y-axis is the circumferential arrangement angle of the 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 wind wheel (equivalent to Figure 7 α1′ in .

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

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

[0056] For example, we can let 2πZ -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 the heat dissipation holes 1112 b may also be determined according to design requirements. Preferably, Z may be greater than or equal to 5 and less than or equal to 47.

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

[0060] See also Figure 8 , on the projection plane perpendicular to the rotation axis of the centrifugal wind wheel 111 ( Figure 8 It is equivalent to the projection of the cross section of the centrifugal wind wheel 111 on the projection plane). A reference circle Ck can be made with the projection of the rotation axis as the center of the circle. The reference circle Ck intersects with the projection of the pressure surface 1112c and the projection of the suction surface 1112d. Among them, with the intersection of the projection of the pressure surface 1112c and the reference circle Ck as the tangent point, a tangent line Q1 tangent to the reference circle Ck can be made. The angle between the tangent line Q1 and the projection of the pressure surface 1112c is the installation angle β of the pressure surface 1112c. Similarly, with the intersection of the projection of the suction surface 1112d and the reference circle Ck as the tangent point, a tangent line Q2 tangent to the reference circle Ck can be made. The angle between the tangent line Q2 and the projection of the suction surface 1112d is the installation angle θ of the suction surface 1112d, wherein θ≤β≤45°. This arrangement can effectively increase the air volume, thereby improving the air outlet effect of the centrifugal fan wheel 111.

[0061] More preferably, the installation angle θ of the suction surface 1112d may 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 partial area of ​​the volute 112 on one side close to the first accommodating groove 1112a is recessed into the first accommodating groove 1112a to form a second accommodating groove 112a, a motor avoidance opening 112b is provided on the bottom wall of the second accommodating groove 112a, a through hole 112c is provided on the bottom wall of the second accommodating groove 112a and / or a portion of the volute 112 located around the groove opening of the second accommodating groove 112a, and a driving motor 113 is installed in the second accommodating groove 112a.

[0063] That is, the driving motor 113 may be installed in the second receiving groove 112 a so that at least a portion of the driving motor 113 may be located in the first receiving groove 1112 a .

[0064] The motor avoidance opening 112 b is used to avoid the driving shaft of the driving motor 113 , that is, the driving shaft of the driving motor 113 can be drivingly connected to the centrifugal wind wheel 111 through the motor avoidance opening 112 b .

[0065] Figure 4 and Figure 5The bottom wall of the second receiving groove 112a and the portion of the volute 112 located around the notch of the second receiving groove 112a are respectively provided with through holes 112c, which can be used for passing the drive motor 113 and for heat dissipation.

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

[0067] Another embodiment of the present application also provides an air conditioner. 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 the centrifugal fan 11 provided in any embodiment of the present 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, heating and other functions.

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

[0070] For example, see Figure 2 The fresh air module 10 may be provided with a filter 12, which includes but is not limited to a HEPA (High Efficiency Particulate Air Filter) filter. The filter 12 is provided 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, the fresh air in the outdoor environment enters the fresh air module 10 from the air inlet 14 of the fresh air module 10 through the fresh air duct. Under the action of the centrifugal wind wheel 111, the fresh air passes through the filter 12 and enters the volute 112 from the side of the volute 112 opposite to the drive motor 113. Another part of the airflow enters the volute 112 from the heat dissipation holes 1112b on the side around 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, see Figure 2 The fresh air module 10 may be provided with a wet membrane 13, which mainly plays a humidification role. The wet membrane 13 may be provided between the filter 12 and the centrifugal wind wheel 111. After the fresh air is filtered by the filter 12, it passes through the wet membrane 13 for humidification.

[0073] In addition to the fresh air function, the fresh air module 10 can also be provided with an internal circulation function, which mainly allows the airflow to circulate in the indoor environment, that is, the internal circulation function only allows the airflow in the indoor environment to circulate without introducing fresh air from the outdoor environment.

[0074] The fresh air module 10 can also be provided 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. A part of the airflow enters the fresh air module 10 from the internal circulation inlet. Under the action of the centrifugal wind wheel 111, the airflow entering from the internal circulation inlet passes through the filter 12 (if a wet film 13 is provided, the airflow passes through the filter 12 and the wet film 13), and enters the volute 112 from the side of the volute 112 opposite to the drive motor 113. Another part of the airflow enters the volute 112 from the heat dissipation holes 1112b on the side around 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 of the embodiment of the present application has a good noise reduction effect, when the fresh air function or the internal circulation function is turned on, the noise of the centrifugal fan 11 is relatively small, thereby providing the user with a comfortable and quiet environment.

[0076] In the description of the present application, the description with reference to the terms "in one embodiment", "in some embodiments", "in other embodiments", "in yet other embodiments", or "exemplary" etc. means that the specific features, regions, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the present application, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, regions, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0077] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A centrifugal wind wheel, characterized in that: include: A plurality of blades, wherein a receiving space is formed on one side of the plurality of blades close to the rotation axis of the centrifugal wind wheel; An end plate, wherein the end plate is arranged at one end of the plurality of blades along the axial direction of the centrifugal wind wheel, a partial area of ​​the end plate is recessed into the accommodating space to form a first accommodating groove, a plurality of heat dissipation holes are arranged on the side wall of the first accommodating groove, and the plurality of heat dissipation holes are arranged at intervals along the circumferential direction centered on the rotation axis, and at least some of the heat dissipation holes are distributed in non-equidistant directions.

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

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

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

5. The centrifugal wind wheel according to claim 4, characterized in that: The center angle is distributed according to the following sinusoidal function: △α k+1 '=2πZ -1 +2Asin(sπZ -1 )cos(sα1+2πks Z -1 +πsZ -1 ) Among them, △α k+1 ' represents the center angle, 1≤k≤Z, and k is an integer, Z represents the total number of the heat dissipation holes, A represents the phase modulation amount, s represents the number of components, and α1 is the circumferential arrangement angle of the first equidistant heat dissipation hole among the Z equidistant heat dissipation holes distributed at equal intervals.

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

7. The centrifugal wind wheel 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 wind wheel according to any one of claims 1 to 6, characterized in that: The wall surfaces on two opposite sides of the heat dissipation hole along the circumferential direction are respectively a pressure surface and a suction surface, and 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°.

9. The centrifugal wind wheel according to any one of claims 1 to 6, characterized in that: Each of the heat dissipation holes passes through a portion of the end plate located on a peripheral side of a notch of the first accommodating groove.

10. A centrifugal fan, characterized in that: It comprises a volute, a drive motor and the centrifugal wind wheel according to any one of claims 1 to 9, wherein the centrifugal wind wheel is arranged in the volute, the drive motor is drivingly connected to the centrifugal wind wheel, and at least a part of the drive motor is located in the first accommodating groove.

11. The centrifugal fan according to claim 10, characterized in that: A partial area of ​​the volute on one side close to the first accommodating groove is recessed into the first accommodating groove to form a second accommodating groove, and a motor avoidance opening is provided on the bottom wall of the second accommodating groove. A through hole is provided on the bottom wall of the second accommodating groove and / or a portion of the volute located on the peripheral side of the groove opening of the second accommodating groove, and the drive motor is installed in the second accommodating groove.

12. An air conditioner, characterized in that: It comprises an air conditioning module and a fresh air module, wherein the fresh air module comprises the centrifugal fan according to claim 10 or 11.

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