CN113107898A

CN113107898A - Blade for centrifugal fan, impeller, centrifugal fan and household appliance

Info

Publication number: CN113107898A
Application number: CN202110483722.7A
Authority: CN
Inventors: 任志文; 林健; 张璧; 任孟珂; 裴杰
Original assignee: Midea Group Co Ltd; Guangdong Midea Kitchen Appliances Manufacturing Co Ltd
Current assignee: Midea Group Co Ltd; Guangdong Midea Kitchen Appliances Manufacturing Co Ltd
Priority date: 2021-04-30
Filing date: 2021-04-30
Publication date: 2021-07-13
Anticipated expiration: 2041-04-30
Also published as: CN113107898B

Abstract

The invention relates to the field of fans, and particularly discloses a blade for a centrifugal fan, an impeller, the centrifugal fan and a household appliance, which comprise: the method comprises the following steps: platy blade body, blade body include anterior segment, middle section and back end at least, and anterior segment, middle section and back end are followed the length direction of blade body arranges, follows the width direction of blade body, anterior segment, middle section and back end have respectively be used for with the first side that centrifugal fan connects and with the second side that first side is relative, the line of the second side of anterior segment, middle section and back end is smooth transition's streamline shape, just the width of anterior segment, middle section and back end increases progressively in proper order. Through dividing into the blade three-section that the width increases progressively, when the air current was flowing through the blade like this, the blade of width constantly increasing can play fine rectification effect to the air current, effectively reduces the production of vortex to reduce centrifugal fan's aerodynamic noise.

Description

Blade for centrifugal fan, impeller, centrifugal fan and household appliance

Technical Field

The invention relates to the field of fans, and particularly discloses a blade for a centrifugal fan, an impeller, the centrifugal fan and a household appliance.

Background

Due to the advantages of large air quantity, low cost and the like, the multi-wing centrifugal fan is widely applied to various technical fields, such as a range hood, an OTR microwave oven and the like, and can greatly improve the oil smoke absorption effect.

A multi-blade centrifugal fan 100' as shown in fig. 1, comprising at least one centrally distributed electric motor 10' for powering the fan 100 '; the left side and the right side of the motor 10 'are respectively provided with a set of impeller 11' and a volute 12', the volute 12' is fixed through a fan bracket 13', and the fan 100' is in a centrifugal form of axial air inlet and radial air outlet, so that the two sides of the motor 10 'are provided with air inlets 14' of the fan 100', on one hand, the effect of increasing the air volume is achieved, and on the other hand, the air flow of the air inlets has a heat dissipation effect on the motor 10'.

The core component of the fan 100' is an impeller 11', when the fan 100' operates, the impeller 11' rotates, and the blades of the impeller 11' disturb airflow, so that the suction function of the fan is realized; however, when the existing fan operates, the air flow forms a larger vortex at the edge of the air outlet side of the blade, which affects the air performance of the fan and generates larger noise pollution.

Disclosure of Invention

The invention mainly aims to provide a blade for a centrifugal fan, an impeller, the centrifugal fan and a household appliance, and aims to solve at least one technical problem.

In order to achieve the above object, the present invention provides a blade for a centrifugal fan, comprising:

the method comprises the following steps: plate-like blade body, the blade body includes anterior segment, middle section and back end at least, the anterior segment is established the blade body is close to the one end of centrifugal fan air intake, anterior segment, middle section and back end are followed the length direction of blade body arranges, follows the width direction of blade body, anterior segment, middle section and back end have respectively be used for with the first side that centrifugal fan connects and with the second side that first side is relative, the line of the second side of anterior segment, middle section and back end is smooth transition's streamline shape, just the width of anterior segment, middle section and back end increases progressively in proper order.

The invention further provides an impeller, which comprises a front end ring, a rear end ring, a dividing ring arranged between the front end ring and the rear end ring, a plurality of first blades arranged between the front end ring and the dividing ring, and a plurality of plate-shaped second blades arranged between the dividing ring and the rear end ring, wherein the first blades are the blades for the centrifugal fan.

The invention also provides a centrifugal fan which comprises a volute, a motor and the impeller, wherein the impeller is arranged in the volute, and one end of the motor is positioned in the impeller.

The invention also provides a household appliance comprising the centrifugal fan.

In addition, the centrifugal fan blade according to the present invention may have the following additional features.

According to an embodiment of the invention, a connecting line of the first side edges of the front section, the middle section and the rear section is linear, and the linear shape is a shape with a front part concave downwards, a middle part convex upwards and a rear part concave downwards along the length direction of the blade body.

According to one embodiment of the invention, the length of the first blade is greater than the length of the second blade, wherein the second blade is provided with a motor avoiding notch.

According to one embodiment of the invention, the second blade has a third side edge and a fourth side edge opposite to the third side edge along the width direction of the second blade, wherein the third side edge comprises a first straight line section and a second straight line section which are arranged in parallel up and down, the first straight line section and the second straight line section are connected through an arc section in a smooth transition mode, and a connecting line of the second straight line section and the arc section forms a contour line of the motor avoidance notch.

According to an embodiment of the invention, the wind turbine further comprises a first fan support and a second fan support, wherein the number of the volutes and the number of the impellers are two, the motors are direct current motors, one impeller is arranged in each volute, the motor is positioned between the two volutes, and support plates for abutting against the shell of the motor are respectively arranged at the relative positions of the first fan support and the second fan support.

According to an embodiment of the invention, two ends of the motor respectively penetrate through the through holes on the first fan support and the second fan support and extend into the impeller, the inner diameter of each through hole is larger than the outer diameter of the motor, the length of each second blade is h, and the length of the motor extending into the impeller is smaller than h/3.

According to one embodiment of the invention, the volute is provided with a stepped volute tongue structure which is arranged at the edge of the inner side of the volute air outlet, and the stepped volute tongue structure comprises at least two volute tongues which are obliquely arranged towards the direction close to the volute air outlet.

Compared with the prior art, the invention has the following beneficial effects:

1. the blades are divided into three sections with gradually increased widths, so that when airflow flows through the blades, the blades with continuously increased widths can play a good role in rectifying the airflow, the generation of vortex is effectively reduced, and the pneumatic noise of the centrifugal fan is reduced;

2. the volute is provided with the stepped volute tongue structure, so that the clearance between the volute tongue positioned below the stepped volute tongue and the impeller is smaller, the flow collecting effect of the volute can be ensured, the wind pressure and the flow of the fan are not lost, the pneumatic performance of the fan is improved, the clearance between the volute tongue positioned above the stepped volute tongue and the impeller is larger, the strong impact of airflow on the volute tongue is avoided, and the pneumatic noise can be effectively reduced;

drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a centrifugal fan in the prior art;

FIG. 2 is a schematic diagram of a volute of the prior art;

FIG. 3 is a schematic structural diagram of a centrifugal fan according to an embodiment of the present invention;

FIG. 4 is a schematic view of a portion of the structure of FIG. 3;

FIG. 5 is a schematic view of a portion of the structure of FIG. 4;

FIG. 6 is a schematic view of a portion of the structure of FIG. 5;

FIG. 7 is a schematic view of a motor mounting mechanism according to an embodiment of the present invention;

FIG. 8 is a schematic view of a portion of the structure of FIG. 7;

FIG. 9 is a schematic structural view of the first fixing rod of FIG. 7;

FIG. 10 is a schematic view of a portion of the structure of FIG. 9;

FIG. 11 is a schematic structural view of the second fixing rod of FIG. 7;

fig. 12 is a schematic view of a fixing structure of a motor according to another embodiment of the present invention;

FIG. 13 is a schematic structural view of a centrifugal fan according to another embodiment of the present invention;

FIG. 14 is a schematic view of the volute of FIG. 13;

FIG. 15 is a cross-sectional view of the volute of FIG. 14;

FIG. 16 is a partial structural view of a volute according to another embodiment of the present invention, where A is a middle dividing line of the dividing ring;

FIG. 17 is a schematic view of the structure of an impeller according to an embodiment of the present invention;

FIG. 18 is a perspective view of an impeller of another embodiment of the present invention, FIG. 1;

FIG. 19 is a perspective view of FIG. 18;

FIG. 20 is a schematic view of the first blade of FIG. 19;

FIG. 21 is a perspective view of the second blade of FIG. 18;

FIG. 22 is a perspective view of FIG. 21; .

Fig. 23 is a schematic view of the flow separation of a gas stream near the impeller inlet in the prior art.

The reference numbers illustrate:

centrifugal fan 100', motor 10', impeller 11', volute 12', air inlet 13', rotating shaft 101', motor support 102', stator 103', fan support 104', screw hole site 14', centrifugal fan 100, volute 10, air outlet 101, air inlet 102, housing 103, stepped volute tongue structure 104, front plate 105, rear plate 106, shroud plate 107, volute tongue 108, front inclined arc surface 108a, rear inclined arc surface 108b, intersecting line 108c, first arc section 108d, second arc section 108e, third arc section 108f, impeller 11, front end ring 110, rear end ring 111, split ring 112, first blade 113, front section 113a, middle section 113b, rear section 113c, second blade 114, motor avoiding gap 114a, third side 114b, fourth side 114c, first straight line section 114b, second straight line section 114e, arc section 114f, reinforcing ring 115, motor 12, first rotating shaft 120, The fan fixing device comprises a second rotating shaft 121, a first fan support 13, a first annular limiting part 130, a first positioning rib 131, a second fan support 14, a second annular limiting part 140, a second positioning rib 141, a first fixing rod 15, a groove 150, a first base 151, a reinforcing rib 152, a first limiting groove 153, a second fixing rod 16, a slideway 160, a second base 161, a second limiting groove 162, an arc-shaped surface 163, an elastic part 17, a sliding block 18, an arc-shaped transition surface 180, a clamping part 19, a supporting plate 20, a screw hole 201 and an airflow inlet 21.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are only for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In addition, the technical solutions in the embodiments of the present invention may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

Centrifugal fan 100 of some embodiments of the present invention is described below with reference to fig. 3-23.

As shown in fig. 3 to 6, an embodiment of the present invention provides a centrifugal fan 100, where the centrifugal fan 100 may be applied to a household appliance such as a range hood, a microwave oven, and the like, the centrifugal fan 100 may be a double-suction centrifugal fan, but the centrifugal fan 100 may also be a single-suction centrifugal fan, and when the centrifugal fan 100 in this embodiment is a double-suction centrifugal fan, the centrifugal fan 100 may include: the fixing mechanism for the centrifugal fan comprises two volutes 10, two impellers 11, a motor 12 and a fixing mechanism for the centrifugal fan, wherein the volute 10 and the motor 12 can be fixed by the fixing mechanism for the centrifugal fan, specifically, the fixing mechanism for the centrifugal fan comprises a first fan support 13 and a second fan support 14, a first fixing rod 15 is arranged on the first fan support 13, a second fixing rod 16 is arranged on the second fan support 14, and the first fixing rod 15 is clamped with the second fixing rod 16 so as to fix the motor 12 between the first fan support 13 and the second fan support 14. In this embodiment, the air discharge amount of the centrifugal fan 100 is increased by the design of the two volutes 10, each volute 10 has a containing cavity, the two impellers 11 correspond to the two volutes 10 one by one, one impeller 11 is arranged in the containing cavity of each volute 10, the axis of the impeller 11 is parallel to or coincides with the axis of the containing cavity, the two volutes 10 are respectively located at two opposite sides of the motor 12, each volute 10 has an air outlet 101 and two air inlets 102 arranged oppositely, the motor 12 includes a first rotating shaft 120 and a second rotating shaft 121 arranged oppositely, and the first rotating shaft 120 and the second rotating shaft 121 are respectively connected with the two impellers 11 to drive the impellers 11 to rotate. Wherein the motor 12 is located outside the volute 10, of course, the invention is not limited thereto, and at least a portion of the motor 12 may also be located in the accommodating cavity of the volute 10. The motor 12 drives the impeller 11 to rotate, and the impeller 11 drives the airflow to flow from the air inlet 102 to the air outlet 101.

It should be noted that, with reference to fig. 5, first rotating shaft 120 and second rotating shaft 121 may rotate synchronously, and of course, first rotating shaft 120 and second rotating shaft 121 may also be controlled independently, thereby increasing the variety of structures of centrifugal fan 100.

With continued reference to fig. 5 to 6, the first fan support 13 and the second fan support 14 are both hollow rectangular supports, the first fan support 13 and the second fan support 14 are respectively sleeved on the end portions of the two volutes 10, and the portions of the first fan support 13 and the second fan support 14 are located at the air outlet 101 so that the air inlets 102 of the two volutes 10 close to each other are spaced apart from the corresponding air outlets 101.

In this embodiment, as shown in fig. 7 to 11, a groove 150 is formed at the clamping end of the first fixing rod 15, an elastic member 17 is disposed in the groove 150, a sliding block 18 is disposed above the elastic member 17, a sliding channel 160 adapted to the first fixing rod 15 is formed on the second fixing rod 16, a top surface of the sliding block 18 protrudes from the groove 150, and abuts against an inner top surface of the sliding channel 160 and a top surface of the sliding block 18 to generate pressure on the elastic member 17, the sliding channel 160 has an inlet end and an outlet end, a clamping portion 19 is disposed above the outlet end, and a bottom surface of the clamping portion 19 abuts against a top surface of the sliding block 18. Specifically, when needing to fix motor 12, can slide the joint end of first dead lever 15 into the slide 160 of second dead lever 16 from the entry end, at the gliding in-process of joint end at slide 160 of first dead lever 15, the top surface of slider 18 and the interior top surface butt of slide 160, in order to produce decurrent pressure to slider 18, thereby compression elastic component 17 warp, until the joint end of first dead lever 15 from exit end roll-off slide 160, the interior top surface of slide 160 is not producing decurrent pressure to slider 18, elastic component 17 bounces slider 18, the slider 18 of bounced 18 and the bottom surface butt of joint portion 19, and then form interference fit with joint portion 19, thereby realize that the joint of first dead lever 15 and second dead lever 16 is fixed. Correspondingly, when the motor 12 needs to be dismounted, the sliding block 18 can be pressed downwards, at the moment, the elastic piece 17 is compressed and deformed, the sliding block 18 slides into the sliding way 160 from the outlet end, in the sliding process of the sliding way 160, the sliding block 18 is subjected to the acting force of the inner top surface of the sliding way 160 to compress the elastic piece 17 until the sliding block 18 slides out of the sliding way 160 from the inlet end, the sliding block 18 releases the compression on the elastic piece 17, and the elastic piece 17 restores to be deformed, so that the first fixing rod 15 is separated from the second fixing rod 16, and the motor 12 is dismounted.

It should be noted that, in other embodiments of the present invention, the first fixing rod 15 and the second fixing rod 16 may also be clamped by using the following structures, and the specific matching structures are as follows: the tail end of the first fixing rod 15 is provided with a groove 150, an elastic part 17 is arranged in the groove 150, a sliding block 18 is arranged above the elastic part 17, the second fixing rod 16 is provided with a sliding way 160 matched with the first fixing rod 15, the top surface of the sliding block 18 is convexly arranged in the groove 150 and is abutted against the inner top surface of the sliding way 160 and the top surface of the sliding block 18 so as to generate pressure on the elastic part 17, a limiting hole communicated with the sliding way 160 is arranged above the sliding way 160, and the limiting hole is matched with the sliding block 18. Specifically, when needing to fix motor 12, can slide the joint end of first dead lever 15 into the slide 160 of second dead lever 16 from the entry end, at the joint end of first dead lever 15 gliding in-process in slide 160, the top surface of slider 18 and the interior top surface butt of slide 160, in order to produce decurrent pressure to slider 18, thereby compression elastic component 17 warp, until slider 18 slides to spacing hole department along slide 160, because the butt of slide 160 contact to slider 18, elastic component 17 resumes deformation, pop out spacing hole with slider 18, the top of slider 18 is blocked in spacing hole this moment, thereby realize that the joint of first dead lever 15 and second dead lever 16 is fixed. Correspondingly, when the motor 12 needs to be dismounted, the sliding block 18 can be pressed downwards, at the moment, the elastic piece 17 is compressed and deformed, the sliding block 18 slides into the sliding way 160 from the limiting hole, in the sliding process of the sliding way 160, the sliding block 18 is subjected to the acting force of the inner top surface of the sliding way 160 to compress the elastic piece 17 until the sliding block 18 slides out of the sliding way 160, the sliding block 18 relieves the compression on the elastic piece 17, and the elastic piece 17 restores to be deformed, so that the first fixing rod 15 is separated from the second fixing rod 16, and the motor 12 is dismounted.

In addition, in other embodiments of the present invention, the first fixing rod 15 may further include a buckle, the second fixing rod 16 may further include a slot, and the first fixing rod 15 and the second fixing rod 16 are clamped by the buckle and the slot. The invention does not limit the clamping manner of the first fixing rod 15 and the second fixing rod 16, and the clamping of the first fixing rod 15 and the second fixing rod 16 is within the protection scope of the invention.

It should be noted that, with reference to fig. 9-10, the cross section of the first fixing rod 15 is T-shaped, the first fixing rod 15 includes a bar-shaped first base 151 and a reinforcing rib 152 vertically connected to the first base 151, the groove 150 is opened on the reinforcing rib 152, and the second fixing rod 16 is opened with a slide 160 having a T-shaped cross section. One end of the first base 151 is fixed on the first fixing rod 15, and one end of the reinforcing rib 152 away from the groove 150 is provided with a first limiting groove 153 surrounding the first annular limiting member 130 at the hollow position of the first fan support 13, and the first limiting groove 153 is clamped with the first annular limiting member 130, so that the first fixing rod 15 and the first fan support 13 are fixed.

Further, with reference to fig. 11, the second fixing rod 16 includes a T-shaped second base 161 and a clamping portion 19 disposed at the top of the second base 161, a second limiting groove 162 is formed by the bottom surface of the clamping portion 19 and the surface of the second base 161, the second limiting groove 140 surrounds the hollow position of the second fan support 14, and the second limiting groove 162 is clamped with the second annular limiting member 140, so as to fix the second fixing rod 16 and the second fan support 14.

It should be noted that, with reference to fig. 5 to 6, 3 first fixing rods 15 are uniformly disposed on the first annular limiting member 130 of the first fan support 13, and correspondingly, 3 second fixing rods 16 are disposed at corresponding positions of the second annular limiting member 140 of the second fan support 14, so that the first fan support 13 and the second fan support 14 stably fix the motor 12 between the first fan support 13 and the second fan support 14 through the fixing rods thereon.

In this embodiment, with reference to fig. 5 to 6, at least two corners of the first fan support 13 are provided with first positioning ribs 131, corresponding positions of the second fan support 14 are provided with second positioning ribs 141, and the first positioning ribs 131 are detachably connected to the second positioning ribs 141. Specifically, before the first fixing lever 15 is clamped with the second fixing lever 16, the first fan bracket 13 and the second fan bracket 14 may be positioned by the first positioning rib 131 and the second positioning rib 141, and then the first fixing lever 15 and the second fixing lever 16 are clamped, so that the assembling efficiency of the first fixing lever 15 and the second fixing lever 16 is improved.

10-11, the top surface of the slide 18 is an arcuate transition surface 180, and the inlet end of the chute 160 has an arcuate surface 163 that mates with the arcuate transition surface 180. Specifically, the arc-shaped surface 163 can guide the arc-shaped transition surface 180, and when the slider 18 slides into the slide 160, the resistance of the slider 18 sliding into the slide 160 can be reduced by the cooperation of the arc-shaped transition surface 180 and the arc-shaped surface 163, so that the slider 18 can smoothly slide into the slide 160.

In another embodiment of this embodiment, the first fan support 13 and the second fan support 14 may further be fixed by the following structure, as shown in fig. 12, support plates 20 for abutting against the housing of the motor 12 are respectively disposed at the relative positions of the first fan support 13 and the second fan support 14, wherein the three support plates 20 are respectively disposed on the first fan support 13 and the second fan support 14, the inner diameter of each support plate 20 is the same as the outer diameter of the motor 12, so as to firmly clamp the motor 22, and meanwhile, a screw hole 201 is formed in each support plate 20 to be tightly fitted with the motor 12, so as to ensure the stability of the position of the motor 12 and prevent vibration.

It should be noted that the screw holes 201 are exposed, which greatly simplifies the installation process compared with the internal fixation of the motor.

As shown in fig. 2, the conventional fan has only one volute tongue 15', the minimum distance between the volute tongue 15' and the impeller 11' is t, and the volute tongue 15' has a great influence on the aerodynamic and noise performance of the centrifugal fan 100', and the conventional structure is difficult to optimize the comprehensive performance. Based on the above problems of the conventional blower, the present embodiment improves the volute tongue structure, and specifically, as shown in fig. 13 to 15, the volute casing 10 in the present embodiment includes a housing 103 and a stepped volute tongue structure 104. The casing 103 comprises a front plate 105, a rear plate 106 and a surrounding plate 107 arranged between the front plate 105 and the rear plate 106, the front plate 105 is provided with an air inlet 102 at a position facing the impeller 11, the rear plate 16 is provided with another air inlet 102 at a position facing the impeller 11, the surrounding plate 107 is in an open ring shape, one end of the stepped volute tongue structure 104 is connected with one end of the surrounding plate 107 in the circumferential direction to form an accommodating cavity together, and the other end of the stepped volute tongue structure 104 is spaced from the other end of the surrounding plate 107 in the circumferential direction to form an air outlet 101. The air enters the accommodating cavity from the air inlet 102 under the action of the impeller 11 and then flows out from the air outlet 101.

In the invention, the stepped volute tongue structure 104 comprises at least two volute tongues 108 which are obliquely arranged towards the direction close to the air outlet 101, and the stepped volute tongue structure is arranged on the volute, so that the clearance between the volute tongue positioned below and the impeller in the stepped volute tongue is smaller, the flow collecting effect of the volute can be ensured, the air pressure and the flow of the fan are not lost, the pneumatic performance of the fan is improved, the clearance between the volute tongue positioned above and the impeller is larger, the strong impact of the air flow on the volute tongue is avoided, and the pneumatic noise can be effectively reduced.

It should be noted that the two volute tongues 108 may be integrally formed to form the stepped volute tongue structure 104, or the two volute tongues 108 may be separately formed and then assembled to form the stepped volute tongue structure 104.

Specifically, the present embodiment will be described by taking a stepped volute tongue structure 104 composed of two volute tongues 108 as an example. In this embodiment, the shapes of the two volute tongues 108 may be the same or different, and this is not limited in this embodiment. For convenience of description, the present embodiment defines the two volute tongues 108 as a first volute tongue R1 and a second volute tongue R2.

In an embodiment of the present invention, as shown in fig. 15, the second volute tongue R2 is located above the first volute tongue R1, and the first volute tongue R1 and the second volute tongue R2 may both be outward convex straight volute tongues, i.e. the radii of the first volute tongue R1 and the second volute tongue R2 are not changed, and R2 is not equal to R1. In this way, the second volute tongue R2 is closer to the exhaust outlet, i.e. the gap between the second volute tongue R2 and the impeller is larger, so that strong impact of airflow on the volute tongue can be avoided, and aerodynamic noise can be effectively reduced. Correspondingly, the first volute tongue R1 is closer to the impeller, so that the flow collecting effect of the volute can be ensured, the wind pressure and the flow of the fan are not lost, and the pneumatic performance of the fan is improved.

In another embodiment of the present invention, as shown in fig. 16, the first volute tongue R1 and the second volute tongue R2 have the same shape and are both curved volute tongues, and the curved volute tongues are arc volute tongues which are concave and asymmetric and are concave towards the direction away from the air outlet.

It is worth mentioning that, curved snail tongue includes preceding terminal surface, snail tongue face, rear end face and fixed surface, and preceding terminal surface is pressed close to or is contacted with front bezel 105, and rear end face is pressed close to or is contacted with rear bezel 106, and snail tongue face is located the one side of air exit 101, and the fixed surface is located the one side relative with snail tongue face, and in this embodiment, the contour line of the front and back end of bounding wall 107 coincides along motor 12 axial projection, and bounding wall 107 is provided with the fixed plate in the position that is close to air exit 101, and the fixed surface and the fixed plate contact of first snail tongue R1, and the fixed surface and the fixed plate of first snail tongue R1 pass through screw fixed connection.

Preferably, with continued reference to fig. 16, the volute tongue surface of each volute tongue 108 is formed by connecting a front inclined arc surface 108a and a rear inclined arc surface 108b which are connected in a smooth transition manner, and an intersection 108c of the front inclined arc surface 108a and the rear inclined arc surface 108b is a most concave part of the curved volute tongue, wherein the front inclined arc surface 108a is an arc surface formed by inclining in a direction away from the motor 12, and the rear inclined arc surface 108b is an arc surface formed by inclining in a direction approaching the motor 12.

In the present embodiment, as shown in fig. 16, the contour line of the front end surface of each volute tongue 108 has a first arc segment 108d, the contour line of the rear end surface has a second arc segment 108e, the contour line of the intersection 108c of the front oblique arc surface 108a and the rear oblique arc surface 108b has a third arc segment 108f, the smooth curved surface connected between the contour line of the front end surface and the intersection contour line constitutes the front oblique arc surface 108a, and the smooth curved surface connected between the contour line of the rear end surface and the intersection contour line constitutes the rear oblique arc surface 108 b; the radius R5 of the first arc segment 108d is greater than the radius R3 of the second arc segment 108e and less than the radius R4 of the third arc segment 108 f. Specifically, the radius of the volute tongue 108 varies continuously along the axial direction of the motor 12, the radius R3 of the side of the volute tongue 108 close to the motor 12 is the smallest, the radius R4 of the intersection line of the middle part of the volute tongue 108 is the largest, and the radius R5 of the volute tongue 108 close to the air inlet 102 on one side is between the two. Specifically, the household appliance generates noise, the airflow at the volute tongue 108 forms a new noise source, and the noise of the household appliance can be as close as possible to the noise generated by the volute tongue through R4R 5R 3, so that the original noise of the household appliance can be better offset.

In this embodiment, as shown in fig. 2, a circle center of the impeller 11 is defined as a point O, and a point at which the first arc segment 108d, the second arc segment 108e, the third arc segment 108f, the forward inclined arc surface 108a, and the backward inclined arc surface 108b have the smallest distance from the outer edge of the impeller 11 is defined as a point a, where an included angle α between a connecting line of the point a and the point O and a horizontal plane passing the point O is in a range of 60 to 95 °.

Further, with reference to fig. 2, the included angles between the connecting line of the point a and the point O on the first circular arc segment 108d and the second circular arc segment 108e and the horizontal plane passing the point O are α 1 and α 2, the included angle between the connecting line of the point a and the point O on the third circular arc segment 108f and the horizontal plane passing the point O is a3, the included angles between the connecting line of the point a and the point O on the front oblique circular arc surface 108a and the rear oblique circular arc surface 108b and the horizontal plane passing the point O are a4 and a5, wherein α 1 and α 2 are greater than any one of α 3, α 4 and α 5, and α 4 and α 5 are greater than α 3. Specifically, the starting angle a of the volute tongue at different positions of the volute tongue 108 is also different, wherein a is called a deep tongue when a is larger, a is called a shallow tongue when a is proper, and a is called a flat tongue when a is smaller; generally, a flat tongue is adopted at the position of R4 (the third arc section 108f), a deep tongue is adopted at the positions of R3 (the second arc section 108e) and R5 (the first arc section 108d), and a shallow tongue is adopted at the transition region (the front inclined arc surface 108a and the rear inclined arc surface 108b), so that the problem caused by uneven speed distribution of an impeller outlet is solved, and the air volume, the air pressure and the efficiency are improved.

With continued reference to fig. 17, the impeller 11 includes a front end ring 110, a rear end ring 111, a split ring 112 disposed between the front end ring 110 and the rear end ring 111, a plurality of first blades 113 disposed between the front end ring 110 and the split ring 112, and a plurality of second blades 114 disposed between the split ring 112 and the rear end ring 111, wherein an intersection line 108c of the forward inclined arc surface 108a and the backward inclined arc surface 108b corresponds to a position of the split ring 112. Specifically, the impeller 11 has a large flow velocity of the airflow in the partition ring 112, and the cross-sectional area at the corresponding intersection line 108c is large, so that the flow velocity of the airflow at the position with the large cross-sectional area is fast, the airflow at each position of the air outlet is more uniform, and the vibration of the volute caused by the nonuniform airflow is avoided. It should be noted that the first vane 113 is disposed close to the air outlet 101, the second vane 114 is disposed far from the air outlet 101, the first vane 113 close to the air outlet 101 conveys the fluid from the outside into the volute 10, the speed direction of the fluid is more biased toward the axial direction of the impeller 11 to increase the air volume of the centrifugal fan 100, the second vane 114 at the portion far from the air outlet 101 generally throws the fluid out of the volute 10, that is, the speed direction of the fluid is more biased toward the radial direction of the impeller 11 to provide the fluid with the pressure flowing toward the air outlet 101 to increase the speed of the fluid flowing toward the air outlet 101, so the flow rate of the fluid at the middle portion of the air outlet 101 is greater than the flow rate of the fluid at the two ends of the air outlet 101. In order to avoid the vibration caused by the uneven flow of the air flow in the air outlet 101, the intersecting line 108c of the front inclined arc surface 108a and the rear inclined arc surface 108b of the present embodiment corresponds to the position of the division ring 112.

Specifically, the intersecting line of the front inclined arc surface 108a and the rear inclined arc surface 108b corresponds to the position of the dividing ring 112 on the impeller 11, the airflow velocity of the impeller 11 at the dividing ring 112 is high, and the cross-sectional area of the corresponding intersecting line is large, so that the airflow velocity at the position with the large cross-sectional area is high, the airflow flow at each position of the air outlet is more uniform, and the vibration of the volute caused by the nonuniform airflow flow is avoided.

With continued reference to fig. 17, in the axial direction of the impeller 11, the length of the first blade 113 is greater than the length of the second blade 114; specifically, the length of the first blade 113 is greater than that of the second blade 114, so that the air suction volume of the whole fan can be greatly increased.

Further, as shown in fig. 18 to 19, the impeller 11 further includes a reinforcing ring 115 disposed on the outer surface of the first blade 113, and the reinforcing ring 115 can enhance the strength of the blade assembly.

With reference to fig. 20 to 22, in this embodiment, the first blade 113 and the second blade 114 are both plate-shaped, the cross sections of the first blade 113 and the second blade 114 are arc-shaped, the first blade 113 is divided into a front section 113a, a middle section 113b and a rear section 113c, wherein the front section 113a is disposed at an end of the first blade 113 close to the centrifugal fan inlet, the front section 113a, the middle section 113b and the rear section 113c are arranged along the length direction of the first blade 113, and the widths of the front section 113a, the middle section 113b and the rear section 113c are sequentially increased. Specifically, since the airflow enters the impeller from the axial direction and is finally discharged out of the impeller in the radial direction, the airflow angle gradually deflects from 0 ° to 90 °, and then the airflow is differently worked at different positions on the first blade 113, and the first blade 113 is divided into a front section 113a, a middle section 113b, and a rear section 113c, which have gradually increased widths, in this embodiment, so that the working efficiency of the first blade 113 can be greatly improved.

It should be noted that the first blade 113 may also be divided into four sections, five sections, six sections, etc., and the embodiment is not limited herein, and those skilled in the art can flexibly select the first blade according to the needs.

Further, in the present embodiment, the thicknesses of the front section 113a, the middle section 113b and the rear section 113c are equal, and along the width direction of the first blade 113, the front section 113a, the middle section 113b and the rear section 113c respectively have a first side and a second side opposite to the first side, wherein a connection line aa of the first sides of the front section 113a, the middle section 113b and the rear section 113c is linear, and a connection line ab of the second sides of the front section 113a, the middle section 113b and the rear section 113c is streamline in smooth transition. Specifically, the connection line aa is located on the air exhaust side of the first blade 113, the connection line ab is located on the air inlet side of the first blade 113, the connection line ab is in an arc streamline shape, and the streamline shape is a shape with a front portion sunken downwards, a middle portion protruded upwards and a rear portion sunken downwards along the length direction of the first blade 113, so that the first blade 113 has a good rectification effect on airflow, the generation of vortex is greatly reduced, and the aerodynamic noise is reduced.

It is worth mentioning that what traditional centrifugal fan adopted is asynchronous AC motor, and asynchronous AC motor's rotational speed has the limitation, therefore causes the fan performance to have great limitation, for example can't realize the miniaturized design of fan, and is different from the asynchronous AC motor that the tradition adopted, and the motor of this embodiment is DC motor, and the DC motor rotational speed can be adjusted, can break through asynchronous AC motor's rotational speed limit, reaches the miniaturized target of whole fan. Further, in order to prolong the service life of the motor and increase the power of the motor, the length of an electric brush in the motor needs to be increased, and generally, the length of the motor is larger; in order to ensure that the length of the whole fan is not too long, the structure of the second blade 114 is improved in this embodiment, specifically, a motor avoiding gap 114a is formed in the second blade 114, so that the two ends of the motor 12 respectively penetrate through the through holes of the first fan support 13 and the second fan support 14 and extend into the impeller 11, the motor avoiding gap 114a can avoid interference between the second blade 114 and the motor 12, and the inner diameter of the through hole is greater than the outer diameter of the motor 12, so that an airflow inlet 21 is formed between the through holes of the motor 12 and the fan support, thereby ensuring that sufficient airflow enters the impeller 11.

In addition, as shown in fig. 23, the flow direction of the airflow on the side of the second vane 114 close to the air inlet is deviated to the axial direction, the airflow has great flow separation at the position, and cannot effectively do work, and the motor avoiding notch 114a can reduce the load and improve the fan efficiency.

It should be noted that, the motor 12 extends into the impeller 11, so that on one hand, more air flows through the motor to achieve a better heat dissipation effect, and on the other hand, the motor 12 can be prevented from occupying too much space, thereby achieving the purpose of fan miniaturization. It is worth mentioning that the length of the second blade 114 is h, and the length of the motor 12 extending into the impeller 11 is less than h/3.

Further, along the width direction of the second blade 114, the second blade 114 has a third side 114b and a fourth side 114c opposite to the third side 114b, wherein the third side 114b includes a first straight line segment 114d and a second straight line segment 114e which are arranged in parallel up and down, the first straight line segment 114b and the second straight line segment 114e are connected through an arc segment 114f in a smooth transition manner, and a connecting line of the second straight line segment 114e and the arc segment 114f forms a contour line of the motor avoidance gap 114 a.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A blade for a centrifugal fan, comprising: plate-like blade body, the blade body includes anterior segment, middle section and back end at least, the anterior segment is established the blade body is close to the one end of centrifugal fan air intake, anterior segment, middle section and back end are followed the length direction of blade body arranges, follows the width direction of blade body, anterior segment, middle section and back end have respectively be used for with the first side that centrifugal fan connects and with the second side that first side is relative, the line of the second side of anterior segment, middle section and back end is smooth transition's streamline shape, just the width of anterior segment, middle section and back end increases progressively in proper order.

2. The blade for a centrifugal fan according to claim 1, wherein a line connecting the first side edges of the front section, the middle section and the rear section is linear, and the linear shape is a shape in which a front portion is concave downward, a middle portion is convex upward, and a rear portion is concave downward along the length direction of the blade body.

3. An impeller comprising a front end ring, a rear end ring, a split ring provided between the front end ring and the rear end ring, a plurality of first blades provided between the front end ring and the split ring, and a plurality of plate-like second blades provided between the split ring and the rear end ring, wherein the first blades are the blades for a centrifugal fan according to claim 1 or 2.

4. The impeller of claim 3, wherein the first blade has a length greater than a length of the second blade, wherein the second blade defines a motor relief notch.

5. The impeller as claimed in claim 4, wherein the second blade has a third side edge and a fourth side edge opposite to the third side edge along a width direction of the second blade, wherein the third side edge comprises a first straight line section and a second straight line section which are arranged in parallel up and down, the first straight line section and the second straight line section are connected through an arc section in a smooth transition mode, and a connecting line of the second straight line section and the arc section forms a contour line of a motor avoidance gap.

6. A centrifugal fan, comprising: a volute, a motor, and an impeller according to any one of claims 3-5, the impeller being disposed within the volute, one end of the motor being located within the impeller.

7. The centrifugal fan according to claim 6, further comprising a first fan support and a second fan support, wherein the number of the volutes and the number of the impellers are two, the motor is a direct current motor, one impeller is arranged in each volute, the motor is located between the two volutes, and support plates for abutting against a housing of the motor are respectively arranged at opposite positions of the first fan support and the second fan support.

8. The centrifugal fan as claimed in claim 7, wherein two ends of the motor respectively penetrate through the through holes of the first fan bracket and the second fan bracket and extend into the impeller, the inner diameter of the through hole is larger than the outer diameter of the motor, the length of the second blade is h, and the length of the motor extending into the impeller is smaller than h/3.

9. The centrifugal fan as claimed in claim 6, wherein the volute has a stepped volute tongue structure disposed at an inner edge of the volute outlet, and the stepped volute tongue structure includes at least two volute tongues inclined toward the volute outlet.

10. Household appliance, characterized in that it comprises a centrifugal fan according to any one of claims 6 to 9.