Centrifugal Fans and Electrical Products

Abstract

To provide a centrifugal fan which, when reduced in size, can maintain an excellent air volume-static pressure characteristic without the need to increase rotation speed of an impeller and avoids an increase in noise.SOLUTION: As for a clearance distance in a radial direction between a circumferential inner wall of a housing and a radial outer end of an impeller, in a cross section perpendicular to a central axis, the clearance distance at a second point of the circumferential inner wall of the housing is 1.1 to 2.2 times the clearance distance at a first point. A connecting line between the first point and a center point of the impeller is orthogonal to a connecting line between the second point and the center point. A portion of the circumferential inner wall of the housing between the first point and the second point is a curve, and a circumferential distance between the first point and an exhaust port is smaller than a circumferential distance between the first point and the second point. The exhaust port and the second point are located on both sides in the circumferential direction of the first point, respectively, and a direction of the connecting line between the first point and the center point is parallel to a direction in which gas flows out from the exhaust port.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to the field of electrical machines, in particular to centrifugal fans and electrical appliances. [Background technology]

[0002] The centrifugal fan has a housing containing an impeller and a motor that drives the impeller to rotate. The housing has an air intake port and an air exhaust port, and when the impeller rotates around its central axis, air is drawn into the housing through the air intake port and flows out of the housing through the air exhaust port.

[0003] In the prior art, the circumferential inner wall of the housing is generally circular, and the central axis of the impeller is aligned with the center of the circle. The gap distance between the radially outer end of the impeller and the inner wall of the housing is generally the same at each circumferential position.

[0004] It should be noted that the above introduction of the technical background is merely provided for the convenience of providing a clearer and more complete explanation of the technical contents of the present invention and for the ease of understanding of those skilled in the art, and the mere fact that these technical contents are described in the background section of the present invention does not constitute public knowledge of the above technical contents by those skilled in the art. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 7-4382 Summary of the Invention [Problem to be solved by the invention]

[0006] The inventors of the present invention have found that in conventional technology, when a centrifugal fan is made smaller, the air volume-static pressure characteristics of the centrifugal fan decrease, and when the impeller rotation speed is increased to improve the air volume-static pressure characteristics, the noise of the centrifugal fan increases. [Means for solving the problem]

[0007] To solve the above or other similar problems, embodiments of the present invention provide a centrifugal fan and an electrical product, in which, in a cross section perpendicular to the central axis, the radial gap distance between the circumferential inner wall of the housing and the impeller at a second point is 1.1 to 2.2 times the radial gap distance at a first point closer to the exhaust port. [Effects of the Invention]

[0008] This means that when the centrifugal fan is made smaller, there is no need to increase the impeller rotation speed, and excellent air volume-static pressure characteristics can be maintained, preventing increased noise.

[0009] One of the beneficial effects of the embodiments of the present invention is that when the centrifugal fan is made smaller, it is possible to maintain excellent air volume-static pressure characteristics without needing to increase the impeller rotation speed, and it is possible to avoid increasing noise.

[0010] With reference to the following description and drawings, particular embodiments of the present invention are disclosed in detail, and the manner in which the principles of the present invention are utilized is shown. It is to be understood that the embodiments of the present invention are not limited thereto. Within the scope of the appended claims, the embodiments of the present invention include all variations, modifications, and equivalents.

[0011] Features described and / or shown for one embodiment may be used in the same or similar manner in one or more other embodiments and may be combined with or replace features of the other embodiments.

[0012] It should be emphasized that the term "comprises" is used in the present text to indicate the presence of a feature, whole element, step or element, but does not exclude the presence or addition of one or more other features, whole elements, steps or elements. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view of a centrifugal fan according to an embodiment of the first aspect of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the centrifugal fan taken along a plane perpendicular to the central axis. [Figure 3] 3 is an axial cross-sectional view of the centrifugal fan as seen from the direction AA in FIG. 2. [Figure 4] FIG. [Figure 5] FIG. 2 is a schematic plan view of an impeller. [Figure 6] 6 is an axial cross-sectional view of the impeller as viewed from the BB direction in FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0014] These and other features of the present invention will become more apparent from the following specification, taken in conjunction with the drawings. While the specification and drawings specifically disclose certain embodiments of the present invention and illustrate some of the embodiments in which the principles of the present invention can be employed, it should be noted that the present invention is not limited to the described embodiments. On the contrary, the present invention encompasses all modifications, variations, and equivalents that fall within the scope of the appended claims. Various embodiments of the present invention will be described below in conjunction with the drawings. These embodiments are illustrative and do not limit the present invention.

[0015] In the embodiments of the present invention, the terms "first," "second," "upper," "lower," etc. are used to distinguish different elements in name, but do not indicate the spatial arrangement or chronological order of those elements, and those elements are not limited by those terms. The term "and / or" includes any and all combinations of one or more of the associated listed terms. The terms "include," "comprise," and "comprises" refer to the presence of stated features, elements, components, or parts, and do not exclude the presence or addition of one or more additional features, elements, components, or parts.

[0016] In the embodiments of the present invention, the singular aspects such as "a" and "the" should be understood broadly to include plural aspects and to mean "one" in a broad sense, such as "one kind" or "one class," but not limited to the meaning of "one." The term "the" should be understood to include both singular and plural aspects unless the context dictates otherwise. The term "by" should be understood to mean "at least in part by ..." unless the context dictates otherwise, and the term "based on" should be understood to mean "at least in part based on ..." unless the context dictates otherwise.

[0017] In the following description of the embodiments of the present invention, for convenience of explanation, the radial direction centered on the central axis of the impeller will be referred to as the "radial direction," the direction surrounding the central axis will be referred to as the "circumferential direction," the direction along or parallel to the central axis will be referred to as the "axial direction," the direction in the axial direction from the second plate portion to the first plate portion will be referred to as the "up" direction, the direction opposite to the "up" direction will be referred to as the "down" direction, the side along the radial direction away from the central axis will be referred to as the "radially outer side," and the side along the radial direction approaching the central axis will be referred to as the "radially inner side."

[0018] It should be noted that the "up" and "down" directions in the present invention are used for the convenience of explaining the present invention and do not limit the orientation of the centrifugal fan during use or manufacturing.

[0019] <Example of the first aspect> An embodiment of a first aspect of the present invention provides a centrifugal fan. Figure 1 is a perspective view of the centrifugal fan, and Figure 2 is a cross-sectional view of the centrifugal fan taken along a line perpendicular to the central axis.

[0020] 1 and 2, the centrifugal fan 1 includes an impeller 11 and a housing 12. The centrifugal fan 1 may further include a motor (not shown).

[0021] The impeller 11 rotates around a central axis C (as shown in FIG. 1), which passes through a center point O of the impeller 11. The motor can be driven to rotate the impeller 11. The housing 12 is formed with an accommodation space for accommodating the impeller 11 and the motor.

[0022] As shown in FIGS. 1 and 2, the housing 12 includes an intake port 12a through which gas flows in and an exhaust port 12b through which gas flows out, and the direction in which the gas flows out of the exhaust port 12b is F.

[0023] The air intake 12a may be located on both the top and bottom sides of the impeller 11. For example, the air intake located on the top side of the impeller 11 may be the first air intake 12a1 (as shown in Figures 1 and 2), and the air intake located on the bottom side of the impeller 11 may be the second air intake 12a2 (as shown in Figure 2).

[0024] As shown in Figure 2, in a cross section perpendicular to the central axis, the direction of the connecting line L1 between the first point 121 on the circumferential inner wall of the housing 12 and the center point O of the impeller 11 is parallel to the direction F in which the gas flows out of the exhaust port 12b.

[0025] As shown in FIG. 2, in a cross section perpendicular to the central axis, a connecting line L2 between a second point 122 on the circumferential inner wall of the housing 12 and the center point O of the impeller 11 is perpendicular to L1.

[0026] The circumferential distance between the first point 121 and the exhaust port 12b is smaller than the circumferential distance between the first point 121 and the second point 122. Alternatively, the exhaust port 12b and the second point 122 may be located on either side of the first point 121 in the circumferential direction.

[0027] The portion of the circumferential inner wall of the housing 12 between the first point 121 and the second point 122 may be curved, which can suppress noise when gas flows inside the housing.

[0028] 2, at a first point 121, the radial gap distance between the circumferential inner wall of the housing 12 and the radial outer end of the impeller 11 is D1. At a second point 122, the radial gap distance between the circumferential inner wall of the housing 12 and the radial outer end of the impeller 11 is D2.

[0029] In the present invention, the ratio of D2 to D1 is 1.1 to 2.2, i.e., D2 is 1.1 to 2.2 times D1. As a result, the radial gap distance between the circumferential inner wall of the housing 12 and the radially outer end of the impeller 11 is not always large, but gradually increases along the circumferential direction from the first point 121 to the second point 122, allowing the size of the housing 12 of the centrifugal fan to be reduced. Furthermore, because the gas flow path within the housing is narrowed and the flow velocity increases, there is no need to increase the rotation speed of the impeller 11, allowing excellent air volume-static pressure characteristics to be maintained. Furthermore, increased noise can be avoided.

[0030] 2, in a cross section perpendicular to the central axis, a connecting line L3 connecting the third point 123 on the circumferential inner wall of the housing 12 to the center point O of the impeller 11 is perpendicular to L2. The first point 121 and the third point 123 may be located on either side of the second point 122 in the circumferential direction. The portion of the circumferential inner wall of the housing 12 between the second point 122 and the third point 123 may be curved, which can suppress noise when gas flows inside the housing.

[0031] As shown in FIG. 2, at the third point 123, the radial gap distance between the circumferential inner wall of the housing 12 and the radial outer end of the impeller 11 is D3.

[0032] In the present invention, the ratio of D3 to D1 is 3.6 to 5.1, i.e., D3 is 3.6 to 5.1 times D1. As a result, the radial gap distance between the circumferential inner wall of housing 12 and the radially outer end of impeller 11 is not always large, but gradually increases along the circumferential direction from second point 122 to third point 123, allowing the size of housing 12 of the centrifugal fan to be reduced. Furthermore, because the gas flow path within the housing is narrowed and the flow velocity increases, there is no need to increase the rotation speed of impeller 11, which further improves the air volume-static pressure characteristics of centrifugal fan 1 and prevents increased noise.

[0033] 2, in a cross section perpendicular to the central axis, a connecting line L4 connecting the fourth point 124 on the circumferential inner wall of the housing 12 to the center point O of the impeller 11 is perpendicular to L3. The second point 122 and the fourth point 124 may be located on either side of the third point 123 in the circumferential direction. The portion of the circumferential inner wall of the housing 12 between the third point 123 and the fourth point 124 may be curved, which can suppress noise when gas flows inside the housing.

[0034] As shown in FIG. 2, at the fourth point 124, the radial gap distance between the circumferential inner wall of the housing 12 and the radial outer end of the impeller 11 is D4.

[0035] In the present invention, the ratio of D4 to D1 is 6.2 to 6.4, i.e., D4 is 6.2 to 6.4 times D1. As a result, the radial gap distance between the circumferential inner wall of housing 12 and the radially outer end of impeller 11 is not always large, but gradually increases along the circumferential direction from third point 123 to fourth point 124, allowing the size of housing 12 of the centrifugal fan to be reduced. Furthermore, because the gas flow path within the housing is narrowed and the flow velocity increases, there is no need to increase the rotation speed of impeller 11, which further improves the air volume-static pressure characteristics of centrifugal fan 1 and prevents increased noise.

[0036] According to the embodiment of the first aspect of the present invention, the radial gap distance between the circumferential inner wall of the housing 12 and the radial outer end of the impeller 11 gradually increases in the circumferential direction from the first point 121 through the second point 122, the third point 123, and the fourth point 124 to the exhaust port 12b. Here, D1 is the minimum value of the radial gap distance between the circumferential inner wall of the housing 12 and the radial outer end of the impeller 11.

[0037] As shown in FIG. 2, the curve between the first point 121 and the second point 122 on the circumferential inner wall of the housing 12, the curve between the second point 122 and the third point 123, and the curve between the third point 123 and the fourth point 124 may be arc lines, which can improve manufacturing convenience.

[0038] The centers of the circles corresponding to the three arc lines may be different and may not overlap with the center O of the impeller 11. For example, the center of the circle corresponding to the arc line between the first point 121 and the second point 122 on the circumferential inner wall of the housing 12 is O1, and the center of the circle corresponding to the arc line between the third point 123 and the fourth point 124 on the circumferential inner wall of the housing 12 is O2, and O1 and O2 do not overlap with O.

[0039] Furthermore, the present invention is not limited to this embodiment. For example, the three curves may not be circular arcs, but may be other types of curves such as parabolas, elliptical curves, etc.

[0040] Fig. 3 is an axial cross-sectional view of the centrifugal fan 1 as viewed from the direction AA in Fig. 2. As shown in Fig. 3, the housing 12 further includes a first plate portion 125, a second plate portion 126, a first side wall portion 127, and a second side wall portion 128.

[0041] The first plate portion 125 is located on one axial side (e.g., the upper side) of the impeller 11, and a first intake port 12a1 is formed in the first plate portion 125, penetrating along the axial direction. The second plate portion 126 is located on the other axial side (e.g., the lower side) of the impeller 11, and a second intake port 12a2 is formed in the second plate portion 126, penetrating along the axial direction. The first side wall portion 127 extends from a radially outer edge of the first plate portion 125 toward the second plate portion 126, for example, the first side wall portion 127 extends downward. The second side wall portion 128 extends from a radially outer edge of the second plate portion 126 toward the first plate portion 125, for example, the second side wall portion 128 extends upward.

[0042] The first side wall portion 127 and the second side wall portion 128 are matingly connected to one another.

[0043] 3, the first side wall portion 127 and the second side wall portion 128 extend axially from the radially outer edges of the first plate portion 125 and the second plate portion 126, respectively, thereby increasing the strength of both the upper and lower portions of the housing 12 and enabling the first plate portion 125 and the second plate portion 126 to be thin. However, the present invention is not limited to this. For example, a side wall may be formed by only the radially outer edge of one of the first plate portion 125 and the second plate portion 126, causing the other of the first plate portion 125 and the second plate portion 126 to have a plate shape. In this way, the plate shape can be made thick, thereby ensuring the strength of the plate shape.

[0044] 4 is a perspective view of the impeller 11, FIG. 5 is a schematic plan view of the impeller 11, and FIG. 6 is an axial cross-sectional view of the impeller as viewed from the direction BB in FIG. As shown in FIGS. 4, 5, and 6, the impeller 11 includes a cup portion 111, a support portion 112, and a rib portion 113 (not shown in FIG. 4).

[0045] The cup portion 111 is located radially outside the motor and is used to house the motor. The support portion 112 is located radially outside the cup portion 111, and a plurality of blades 114 extending radially are arranged along the circumferential direction on the support portion 112. The rib portion 113 may connect the cup portion 111 and the support portion 112, and may be provided along the radial direction.

[0046] 6, the radially outer edge 112a of the support portion 112 may be the radially outermost portion of the impeller 11. In other words, the radially outer end of the impeller 11 refers to the radially outer edge 112a of the support portion 112. For example, the radially outer edge 112a of the support portion 112 is positioned radially outward of the radially outer edge 114a of the blade 114. This allows the radially outer edge 112a of the support portion 112 to protect the radially outer edge 114a of the blade 114.

[0047] In the present invention, the cup portion 111 may be connected to the rotating shaft (not shown) or rotor of the motor, so that when the rotor of the motor rotates, the cup portion 111 rotates together with the support portion 112, thereby causing the blades to rotate.

[0048] In the present invention, the number of rib portions 113 may be three or more, and the three or more rib portions 113 may be distributed at equal intervals in the circumferential direction, thereby enabling a stable connection between the cup portion 111 and the support portion 112.

[0049] In addition, the three or more rib portions 113 may have the same radial size, which makes the radial outer edge of the cup portion 111 and the radial outer edge of the support portion 112 concentric, which is advantageous for stable distribution of airflow within the impeller.

[0050] 4 and 6, the impeller 11 may further include a reinforcing rib 115. The reinforcing rib 115 is annular, provided radially outward of the cup portion 111, and positioned axially below the support portion 112. The reinforcing rib 115 passes through the blades 114 and is connected to each of the blades 114, thereby increasing the strength of the impeller 11.

[0051] According to the embodiment of the first aspect of the present invention, when the size of the housing of the centrifugal fan is reduced, it is possible to maintain excellent air volume-static pressure characteristics and avoid an increase in noise.

[0052] <Example of the second aspect> An embodiment of the second aspect of the present invention provides an electrical appliance comprising the centrifugal fan according to the embodiment of the first aspect.

[0053] In the embodiment of the first aspect, the structure of the centrifugal fan has been described in detail, but the contents thereof are incorporated herein and the description thereof will be omitted.

[0054] According to the second aspect of the present invention, when the size of the housing of the centrifugal fan in an electrical appliance is reduced, it is possible to maintain excellent airflow-static pressure characteristics and avoid an increase in noise, which is advantageous for miniaturizing the electrical appliance and controlling noise.

[0055] Although the present invention has been described above in combination with specific embodiments, those skilled in the art should understand that these descriptions are merely illustrative and do not limit the scope of protection of the present invention. Those skilled in the art can make various modifications and alterations to the present invention based on the spirit and principles of the present invention, and these modifications and alterations are also within the scope of the present invention.

[0056] Elements and features described in one drawing or one embodiment of the present invention may be combined with elements and features shown in one or more other drawings or embodiments, and in the drawings, like reference numerals may indicate corresponding parts in the several drawings and may indicate corresponding parts used in one or more embodiments.

[0057] The accompanying drawings are provided for a better understanding of the embodiments of the present invention, constitute a part of the specification, illustrate preferred embodiments of the present invention, and together with the written description, explain the principles of the present invention. The accompanying drawings described below are merely some embodiments of the present invention, and it is obvious to those skilled in the art that other accompanying drawings can be obtained based on the accompanying drawings without requiring any inventive or creative efforts.

Claims

1. an impeller that rotates around a central axis; a motor that rotates the impeller; a housing that houses the impeller and the motor and includes an intake port through which gas flows in and an exhaust port through which gas flows out; and A radial gap distance between a circumferential inner wall of the housing and a radial outer end of the impeller is In a cross section perpendicular to the central axis, a gap distance at a second point on a circumferential inner wall of the housing is 1.1 to 2.2 times the gap distance at the first point, a connecting line between the first point and the center point of the impeller is perpendicular to a connecting line between the second point and the center point; a portion of the circumferential inner wall of the housing between the first point and the second point is an arc line, and a circumferential distance between the first point and the exhaust port is smaller than a circumferential distance between the first point and the second point; the exhaust port and the second point are located on both sides of the first point in the circumferential direction, a direction of a connecting line between the first point and the center point is parallel to a direction in which the gas flows out of the exhaust port; In a cross section perpendicular to the central axis, a gap distance at a third point on the circumferential inner wall of the housing is 3.6 to 5.1 times the gap distance at the first point; a connecting line between the second point and the center point is perpendicular to a connecting line between the third point and the center point; the third point and the first point are located on both sides of the second point in the circumferential direction, a portion of the circumferential inner wall of the housing between the second point and the third point is a curve; In a cross section perpendicular to the central axis, a gap distance at a fourth point on the circumferential inner wall of the housing is 6.2 to 6.4 times the gap distance at the first point, a connecting line between the third point and the center point is perpendicular to a connecting line between the fourth point and the center point; the second point and the fourth point are located on both sides of the third point in the circumferential direction, a portion of the circumferential inner wall of the housing between the third point and the fourth point is an arc line; a first circle center corresponding to an arc line between the first point and the second point on the inner wall of the housing in the circumferential direction and a second circle center corresponding to an arc line between the third point and the fourth point on the inner wall of the housing in the circumferential direction do not overlap with the center point; Centrifugal fan.

2. 2. The centrifugal fan according to claim 1, wherein a radial gap distance between a circumferential inner wall of the housing and a radially outer end of the impeller increases in a circumferential direction from the first point, through the second point, the third point, and the fourth point, to the exhaust port.

3. The housing includes: a first plate portion located on one axial side of the impeller and having a first intake port penetrating along the axial direction; a second plate portion located on the other side of the impeller in the axial direction and having a second intake port penetrating along the axial direction; 3. The centrifugal fan according to claim 1, further comprising: a first side wall portion extending from a radially outer edge of the first plate portion toward the second plate portion; and a second side wall portion extending from the radially outer edge of the second plate portion toward the first plate portion.

4. The centrifugal fan according to claim 3 , wherein the first side wall portion and the second side wall portion are connected to each other so as to engage with each other.

5. The impeller is a cup portion located radially outward of the motor and configured to accommodate the motor; a support portion located radially outward of the cup portion, the support portion having a plurality of radially extending blades arranged in a circumferential direction; 5. The centrifugal fan according to claim 1, further comprising a rib portion connecting the cup portion and the support portion.

6. 6. The centrifugal fan according to claim 5, wherein the number of the ribs is three or more.

7. 7. The centrifugal fan according to claim 6, wherein three or more of the rib portions have the same radial size.

8. An electrical appliance comprising the centrifugal fan according to any one of claims 1 to 7.

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