CENTRIFUGAL HEAT DISSIPATION FAN
A centrifugal heat dissipation fan including a housing and an impeller is provided. The housing has at least one inlet and at least one outlet. The impeller is disposed in the housing and rotates about an axis. The inlet is located in an axial direction of the axis and corresponds to the impeller. The outlet is located in a radial direction relative to the axis. The inlet is divided into a compression section and a release section in the rotation direction of the impeller, and the compression section has a uniform first radial dimension relative to the axis. The release section has an extended second radial dimension relative to the axis, and the second radial dimension is greater than the first radial dimension.
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This application claims the priority benefit of Taiwan application serial no. 108118049, filed on May 24, 2019. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
BACKGROUND Technical FieldThe disclosure relates to a fan. More particularly, the disclosure relates to a centrifugal heat dissipation fan.
Description of Related ArtIn the current trend, electronic apparatuses (e.g., notebook computers or tablet computers) are gradually designed to be light and thin, and as such, heat dissipation fans installed in the internal space of the electronic apparatuses are required to be miniaturized as the internal space is limited. Since the space is limited, airflow of the heat dissipation fans may not smoothly enter or exit the heat dissipation fans, so that heat dissipation efficiency of the fans is thus affected.
Taking a centrifugal heat dissipation fan for example, the flowing path needs to be designed to be scroll-like in a gradually extending manner, so that sufficient pressure differences are generated when the working fluid flows in or out of the fan. In this way, the working fluid enters the fan in the axial direction and is discharged from the fan in the radial direction through changes of such pressure differences. Nevertheless, through such design, at the location where the flowing path gradually expands, since the working fluid turns (from the axial direction to the radial direction) at a high speed, noise is easily generated.
Therefore, how to change the related structure of the existing centrifugal heat dissipation fans so as to address the noise problem is an important issue in this field.
SUMMARYThe disclosure provides a centrifugal heat dissipation fan in which a compression section and a release section of different dimensions are formed at an inlet, so that a trajectory of a working fluid is accordingly improved, and less noise is thus generated.
A centrifugal heat dissipation fan provided by an embodiment of the disclosure includes a housing and an impeller. The housing has at least one inlet and at least one outlet. The impeller is disposed in the housing and rotates about an axis. The inlet is located in an axial direction of the axis and corresponds to the impeller. The outlet is located in a radial direction relative to the axis. The inlet is divided into a compression section and a release section in the rotation direction of the impeller, and the compression section has a uniform first radial dimension relative to the axis. The release section has an extended second radial dimension relative to the axis, and the second radial dimension is greater than the first radial dimension.
In view of the above, the compression section and the release section having different dimensions are formed at the inlet of the centrifugal heat dissipation fan. The compression section has the uniform first radial dimension with respect to the rotation axis of the impeller, the release section has the extended second radial dimension with respect to the rotation axis of the impeller, and the second radial dimension is greater than the first radial dimension. In this way, when entering the housing from the release section, the working fluid is directly pushed towards the outlet by the airflow in the housing without flowing through the blade area of the impeller. Therefore, turning of the trajectory of the working fluid is effectively reduced, and the noise generated is accordingly reduced.
To make the aforementioned more comprehensible, several embodiments accompanied with drawings are described in detail as follows.
The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.
With reference to
Further, the blades 122 have a third radial dimension L3 with respect to the axis C1. As regards the inlet E1 and the working fluid entering the housing 110 through the inlet E1, a portion of the working fluid entering the housing 110 through the compression section E11 is compressed when the impeller 120 rotates. The compression section E11 starts from a starting point ST1 corresponding to a tongue portion 112a of the housing 110. From the starting point ST1 to an end point EN1 of the compression section E11, the portion of the working fluid entering the housing 110 from this area is compressed by the impeller 120. In this embodiment, a central angle θ1 of the compression section E11 with respect to the axis C1 is 175 degrees to 215 degrees (from the starting point ST1 to the end point EN1). Moreover, in this embodiment, in the compression section E11, the third radial dimension L3 of the blades 122 is greater than the first radial dimension L1 of the compression section E11 (L3>L1), so that the portion of the working fluid is prevented from leaking out from the same position when entering the housing 110 through the compression section E11.
Next, the working fluid is continuously compressed by the impeller 120 in the housing 110. When the blades 122 of the impeller 120 of this embodiment pass through the release section E12, since the second radial dimension L2 of the release section E12 is variable and extended, the difference between the third radial dimension L3 and the second radial dimension L2 is gradually reduced, until portions of the release section E12 expose ends of the blades 122. That is, as shown in a region A1 of
In other words, if a plane P1 on which the outlet E2 is located is treated as the basis, the starting point ST2 of the release section E12 is a location at which rotation is performed by a central angle θ3 around the axis C1 based on a radial plane P2 with respect to the axis C1, where the central angle θ3 is 20 degrees. The radial plane P2 is parallel to the plane P1 on which the outlet E2 is located, and the direction of the 20-degree rotation is opposite to the rotation direction of the impeller 120 (the clockwise direction in
In addition, with reference to
Based on the foregoing corresponding relations between member configuration and member dimensions, the centrifugal heat dissipation fan 100 may achieve the effect of reducing turning of a trajectory of the working fluid at the release section E12. In contrast, in a centrifugal heat dissipation fan of the related art, a trajectory of a working fluid is required to be driven by blades to turn so that the working fluid may be discharged in the radial direction after making an entry in the axial direction. Compared to such centrifugal heat dissipation fan of the related art, in this embodiment, the working fluid is less susceptible to be or is prevented from being in contact with the blades 122 at the release section E12. Instead, the portion of the working fluid entering the housing 110 from the release section E12 is more susceptible to be or is completely driven by the portion of the working fluid being compressed at the compression section E11 to be discharged from the housing 110. In this way, noise generated by the working fluid when passing through and being in contact with the blades 122 is effectively lowered.
As the release section is defined by flow velocity changes in the flow field, different variation profiles may thus be formed therefrom.
Next, with reference to
In this embodiment, since the first outlet E5 and the second outlet E6 are provided, a compression section E41 and a release section of the inlet E4 are required to be accordingly adjusted. Further, the release section of this embodiment is divided into a first sub section E42 and a second sub section E43. The first sub section E42 corresponds to the first outlet E5, the second sub section E43 corresponds to the second outlet E6, and the first sub section E42 is connected between the compression section E41 and the second sub section E43 in the rotation direction (the counter-clockwise rotation is adopted in
Specifically, the compression section E41 starts from a starting point ST3 corresponding to a tongue portion 212a of the housing 210. That is, the tongue portion 212a acts as a starting point (the starting point ST3 of the compression section E412) of compression performed by the impeller 120 to the working fluid flowing into the housing 210. An end point EN3 of the compression section E41 is a starting point ST4 of the release section (based on the first sub section E42), and a central angle θ4 of the compression section E41 with respect to an axis C2 is 85 degrees to 125 degrees. Next, the starting point ST4 of the release section is the end point EN3 of the compression section E41, and an end point EN4 of the release section is a point obtained through rotation by a central angle θ5 starting from the starting point ST4. Herein, the central angle θ5 is 40 degrees to 220 degrees.
From another perspective, similar to the foregoing embodiments, the first outlet E5 may also be treated as the basis for defining the starting point ST4 of the release section in this embodiment. For instance, based on a radial plane P4 generated by the axis C2, the starting point ST4 of the release section may be obtained through rotation of the radial plane P4 by a central angle θ6 in a direction opposite to the rotation direction of the impeller 120. Herein, the central angle θ6 is 20 degrees, and the radial plane P4 is parallel to a plane P3 on which the first outlet E5 is located. In addition, as regards the second outlet E6, the starting point ST4 of the release section may also be obtained through the similar manner (i.e., a plane P5 on which the second outlet E6 is located and a radial plane P6). Nevertheless, it is worth noting that an angle change is presented between the first outlet E5 and the second outlet E6, and as shown in
In this embodiment, a first radial dimension of the compression section E41 is similar to the first radial dimension L1 of the compression section E11 described above, a second radial dimension of the release section (the first sub section E42 and the second sub section E43) is also similar to the second radial dimension L2 of the release section E12 described above, and the blades 122 also have a third radial dimension identical to the third radial dimension L3 provided in the foregoing embodiments, the corresponding relations related to the radial dimensions are thus no longer described. Note that similar to the foregoing embodiments, the flow velocity of the flow field in the housing 210 of the centrifugal heat dissipation fan 200 is used to divide the release section. The second radial dimension of the release section gradually extends from the first radial dimension of the compression section E41 to reach the first sub section E42 and gradually shrinks to the first radial dimension of the compression section E41 from the second sub section E43. Moreover, the working fluid reaches the maximum value of flow velocity respectively at the first sub section E42 and the second sub section E43, respectively, so that a region A2 shown in
As described above, it can thus be known that the sound pressure corresponding to the frequency of 3048.63 (Hz) is 22.18 dB(A) in
Further, with reference to
According to the illustration of
In view of the foregoing, in the embodiments of the disclosure, the compression section and the release section having different dimensions are formed at the inlet of the centrifugal heat dissipation fan. The compression section has the uniform first radial dimension with respect to the rotation axis of the impeller, the release section has the extended second radial dimension with respect to the rotation axis of the impeller, and the second radial dimension is greater than the first radial dimension. In this way, when entering the housing from the release section, the working fluid is directly pushed towards the outlet by the airflow in the housing without flowing through the blade area of the impeller. Therefore, turning of the trajectory of the working fluid is effectively reduced, and the noise generated by the working fluid in contact with the impeller is accordingly reduced.
Further, regardless of the single outlet structure or the double outlet structure to be provided in the centrifugal heat dissipation fan, the release sections of the two structures are arranged in the same manner, and such arrangement is required to be made based on the flow velocity of the flow field formed by the working fluid in the housing. In this way, the location in the flow field at which the flow velocity occurs corresponds to the location of the inlet at which the extended radial dimension reaches the maximum value, so that the portion of the working fluid flowing into the housing from such location may be pushed by the compressed portion of the working fluid.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure covers modifications and variations provided that they fall within the scope of the following claims and their equivalents.
Claims
1. A centrifugal heat dissipation fan, comprising:
- a housing, having at least one inlet and at least one outlet; and
- an impeller, disposed in the housing, rotating about an axis, the at least one inlet located in an axial direction of the axis and corresponding to the impeller, the at least one outlet located in an radial direction relative to the axis, the at least one inlet divided into a compression section and a release section in a rotation direction of the impeller, wherein the compression section has a uniform first radial dimension relative to the axis, the release section has an extended second radial dimension relative to the axis, and the second radial dimension is greater than the first radial dimension.
2. The centrifugal heat dissipation fan as claimed in claim 1, wherein the impeller rotates and causes a working fluid to flow into the housing through the at least one inlet and flow out of the housing though the at least one outlet, and a flow velocity of the working fluid in the housing reaches a maximum value at the release section.
3. The centrifugal heat dissipation fan as claimed in claim 1, wherein the impeller rotates and causes a working fluid to flow into the housing through the at least one inlet and flow out of the housing though the at least one outlet, the second radial dimension gradually extends from the first radial dimension to a maximum value and then gradually reduces to the first radial dimension, and a location where the second radial dimension reaches the maximum value is a location where the flow velocity of the working fluid reaches a maximum value.
4. The centrifugal heat dissipation fan as claimed in claim 1, wherein the release section has a toothed shape.
5. The centrifugal heat dissipation fan as claimed in claim 1, wherein the second radial dimension is uniform.
6. The centrifugal heat dissipation fan as claimed in claim 1, wherein the second radial dimension is 1.2 to 1.5 times greater than the first radial dimension.
7. The centrifugal heat dissipation fan as claimed in claim 1, wherein blades of the impeller have a third radial dimension relative to the axis, and the first radial dimension is 70% to 85% of the third radial dimension.
8. The centrifugal heat dissipation fan as claimed in claim 1, wherein the impeller rotates and causes a working fluid to flow into the housing through the at least one inlet and flow out of the housing though the at least one outlet, and at least portions of the release section expose ends of the blades when the blades of the impeller pass through the release section, so that a portion of the working fluid flowing into the housing from the at least portions is not in contact with the blades of the impeller.
9. The centrifugal heat dissipation fan as claimed in claim 1, wherein the housing has a tongue portion, the tongue portion corresponds to a starting point of the compression section in the rotation direction of the impeller, and a central angle provided between the starting point of the compression section and an end point of the compression section relative to the axis is 175 degrees to 215 degrees.
10. The centrifugal heat dissipation fan as claimed in claim 1, wherein the housing has a tongue portion, the tongue portion corresponds to a starting point of the compression section in the rotation direction of the impeller, a starting point of the release section is an end point of the compression section, and a central angle provided between the starting point of the release section and an end point of the release section relative to the axis is 40 degrees to 130 degrees.
11. The centrifugal heat dissipation fan as claimed in claim 1, wherein a starting point of the release section is a position obtained through rotation by +/−20 degrees about the axis relative to a radial direction of the axis, and the radial direction is parallel to a plane where the at least one outlet is located.
12. The centrifugal heat dissipation fan as claimed in claim 1, wherein the housing has a first outlet and a second outlet, the release section is divided into a first sub section and a second sub section, the first sub section corresponds to the first outlet, the second sub section corresponds to the second outlet, and the first sub section is connected between the compression section and the second sub section in the rotation direction of the impeller.
13. The centrifugal heat dissipation fan as claimed in claim 12, wherein a flow velocity of the working fluid in the housing reaches a maximum value respectively at the first sub section and the second sub section.
14. The centrifugal heat dissipation fan as claimed in claim 12, wherein the impeller rotates and causes a working fluid to flow into the housing through the at least one inlet and flow out of the housing though the at least one outlet, the second radial dimension gradually extends from the first radial dimension to reach the first sub section and gradually reduces to the first radial dimension from the second sub section, and a flow velocity of the working fluid reaches a maximum value respectively at the first sub section and the second sub section.
15. The centrifugal heat dissipation fan as claimed in claim 12, wherein the release section has a plurality of radial depressions, and blades of the impeller are exposed when passing through each of the radial depressions.
16. The centrifugal heat dissipation fan as claimed in claim 12, wherein the housing has a tongue portion, the tongue portion corresponds to a starting point of the compression section in the rotation direction of the impeller, and a central angle provided between the starting point of the compression section and an end point of the compression section relative to the axis is 85 degrees to 125 degrees.
17. The centrifugal heat dissipation fan as claimed in claim 12, wherein the housing has a tongue portion, the tongue portion corresponds to a starting point of the compression section in the rotation direction of the impeller, a starting point of the release section is an end point of the compression section, and a central angle provided between the starting point of the release section and an end point of the release section relative to the axis is 40 degrees to 220 degrees.
18. The centrifugal heat dissipation fan as claimed in claim 12, wherein a starting point of the release section is a position obtained through rotation by +/−20 degrees about the axis relative to a radial direction of the axis, and the radial direction is parallel to a plane where the at least one outlet is located.
Type: Application
Filed: Apr 27, 2020
Publication Date: Nov 26, 2020
Applicant: Acer Incorporated (New Taipei City)
Inventors: Tsung-Ting Chen (New Taipei City), Wen-Neng Liao (New Taipei City), Cheng-Wen Hsieh (New Taipei City), Kuang-Hua Lin (New Taipei City), Wei-Chin Chen (New Taipei City), Chun-Chieh Wang (New Taipei City)
Application Number: 16/858,756