Fan and water heater

Abstract

A fan and a water heater. The fan (10) comprises a volute assembly (100) and an impeller (200), wherein the impeller (200) comprises at least two layers of blade sets arranged in the axial direction, each layer of blade set comprising a plurality of blades (220) arranged at intervals in the circumferential direction of the impeller (200), the blades (220) of two adjacent layers of blade sets being staggered; and volute tongue clearance (141) between a volute tongue (140) and the impeller (200) is arranged non-equidistantly in the axial direction of the volute assembly (100). The fan can reduce the formation of vortex and turbulence, and reduce noise.

Description

Fan and water heater

[0001] This application claims priority to the Chinese patent application No. 202421529396.4, filed on June 28, 2024, with the Chinese Patent Office, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of water heaters, in particular to a fan and a water heater. BACKGROUND

[0003] In modern industrial and building environments, fans are widely used in ventilation, refrigeration, air purification and other fields. However, the noise generated by the fan during operation is relatively high, and high noise not only affects the comfort of the working and living environment, but also may have adverse effects on human health. TECHNICAL SOLUTION

[0004] The main purpose of the present application is to provide a fan and a fan, which aims to reduce the noise of the fan.

[0005] To achieve the above-mentioned purpose, the fan provided by the present application comprises:

[0006] A volute assembly having a fan cavity, an air inlet and an air outlet communicating with the fan cavity, the volute comprising a volute tongue arranged corresponding to the air outlet;

[0007] An impeller arranged in the fan cavity, the impeller comprising at least two layers of blade groups arranged along the axial direction, each layer of blades comprising a plurality of blades arranged at intervals along the circumferential direction of the impeller, the blades of the adjacent two layers of blade groups being arranged in a staggered manner, and the volute tongue gap between the volute tongue and the impeller being arranged in a non-equidistant manner in the axial direction of the volute assembly.

[0008] In an embodiment, in the axial direction of the volute assembly, the volute tongue gap gradually increases or gradually decreases from one end of the volute assembly to the other end.

[0009] In an embodiment, the volute assembly has two ends arranged opposite along the axial direction, and the volute tongue gap gradually decreases from the two ends of the volute assembly to the middle.

[0010] In an embodiment, in the axial direction of the volute assembly, the volute tongue gap corresponding to the central position of the volute tongue is the smallest.

[0011] In an embodiment, the outlet height of the impeller is the sum of the vertical distances from the outlet edges of any blade in each layer of blade groups to the central axis of the impeller, and the ratio between the outlet height of the impeller and the outer diameter of the impeller is a width-diameter ratio, the width-diameter ratio is not less than 0.4 and not greater than 0.6.

[0012] In an embodiment, a ratio between an outlet height of the volute assembly and an outer diameter of the impeller is not less than 0.6 and not more than 0.7.

[0013] In an embodiment, the volute assembly is provided with a gap between an inner wall of a side of the air inlet and the impeller not less than 3 mm and not more than 6 mm.

[0014] In an embodiment, the volute assembly further comprises a volute body having a mounting opening and a cover plate covering the mounting opening.

[0015] In an embodiment, the cover plate comprises a plate body and a protruding portion provided on the plate body, the plate body and the volute body enclosing the fan cavity; the protruding portion is annularly arranged, the protruding portion covering a stator assembly of the motor, the protruding portion and the stator assembly being integrally formed, the protruding portion enclosing a motor cavity for mounting a rotor assembly of the motor.

[0016] In an embodiment, the volute further comprises an insert, the insert and the cover plate being integrally formed, the insert being connected with the volute body.

[0017] The application also provides a water heater comprising the fan according to any one of the preceding embodiments. Advantages

[0018] The technical solution of the application can effectively break and disperse the vortex structure of the air flow and change the air flow path, so that the air flow passes through the impeller more smoothly, the formation and intensity of the vortex are reduced, and thus the vortex noise is reduced. In addition, the technical solution of the application sets the volute tongue gap in the axial direction as a non-equidistant, so as to change the air flow direction, reduce the formation of vortex and turbulent flow, and make the air flow more stable, and thus reduce the noise. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0020] Fig. 1 is a structural schematic view of an embodiment of the fan assembly provided by the application;

[0021] Fig. 2 is a sectional view in one direction of Fig. 1;

[0022] Fig. 3 is an enlarged view of A in Fig. 2;

[0023] Fig. 4 is an exploded view of Fig. 1;

[0024] Fig. 5 is a structural schematic view of an embodiment of the insert in Fig. 4;

[0025] Fig. 6 is a structural schematic view of an embodiment of the end cover in Fig. 4;

[0026] Fig. 7 is a structural schematic view of an embodiment of the volute body in Fig. 4;

[0027] Fig. 8 is a sectional view of the end cover in Fig. 4 in one direction;

[0028] Fig. 9 is a structural schematic view of another embodiment of the fan assembly provided by the present application;

[0029] Fig. 10 is a side view of Fig. 9;

[0030] Fig. 11 is a sectional view of Fig. 10 along A-A;

[0031] Fig. 12 is a structural schematic view of another embodiment of the sectional view shown in Fig. 11;

[0032] Fig. 13 is a structural schematic view of still another embodiment of the sectional view shown in Fig. 11;

[0033] Fig. 14 is a different cross-sectional velocity vector distribution diagram of the volute tongue in an embodiment in which the volute tongue gap is equidistantly arranged in the axial direction of the volute, wherein (a) is at the center plane of the volute, (b) is at the cross section close to the bottom end, and the distance is 0.02 m, and (c) is at the cross section close to the air inlet of the volute, and the distance is 0.02 m;

[0034] Fig. 15 is a different cross-sectional velocity vector distribution diagram of the volute tongue in an embodiment in which the volute tongue gap is non-equidistantly arranged in the axial direction of the volute, wherein (a) is at the center plane of the volute, (b) is at the cross section close to the bottom end, and the distance is 0.02 m, and (c) is at the cross section close to the air inlet of the volute, and the distance is 0.02 m;

[0035] Fig. 16 is a different cross-sectional velocity vector distribution diagram of the volute tongue in another embodiment in which the volute tongue gap is non-equidistantly arranged in the axial direction of the volute, wherein (a) is at the center plane of the volute, (b) is at the cross section close to the bottom end, and the distance is 0.02 m, and (c) is at the cross section close to the air inlet of the volute, and the distance is 0.02 m;

[0036] Fig. 17 is a pressure distribution diagram of the center cross section of the impeller volute under the condition that the outlet static pressure P is 300 Pa, wherein (a) is for a width-diameter ratio of 0.519, (b) is for a width-diameter ratio of 0.506, and (c) is for a width-diameter ratio of 0.439;

[0037] Fig. 18 is a velocity vector diagram of the impeller near the bottom surface of the volute (0.02 m from the center surface of the impeller) when the outlet static pressure is 0 Pa, wherein (a) the width-diameter ratio is 0.519, (b) the width-diameter ratio is 0.506, and (c) the width-diameter ratio is 0.439;

[0038] Fig. 19 is a pressure distribution diagram of the impeller near the bottom surface of the volute (0.02 m from the center surface of the impeller) when the outlet static pressure P is 0 Pa, wherein (a) the width-diameter ratio is 0.519, (b) the width-diameter ratio is 0.506, and (c) the width-diameter ratio is 0.439;

[0039] Fig. 20 is a meridian plane velocity vector distribution diagram of the inlet of the volute when the outlet static pressure P is 0 Pa, wherein (a) the ratio of the outlet height of the volute to the outer diameter of the impeller is 0.61, (b) the ratio of the outlet height of the volute to the outer diameter of the impeller is 0.65, and (c) the ratio of the outlet height of the volute to the outer diameter of the impeller is 0.68;

[0040] Fig. 21 is a characteristic curve diagram of the fan and the prototype of three embodiments when the ratio of the outlet height of the volute to the outer diameter of the impeller is between 0.6 and 0.7;

[0041] Fig. 22 is a characteristic curve diagram of the fan and the prototype of three embodiments when the profile parameter of the impeller is between 0.4 and 0.6;

[0042] Fig. 23 is a characteristic curve diagram of the fan and the prototype of three embodiments when the ratio of the outlet height of the volute to the outer diameter of the impeller is between 0.6 and 0.7;

[0043] Fig. 24 is the inlet noise value of an embodiment of the fan of the application;

[0044] Fig. 25 is the outlet noise value of an embodiment of the fan of the application.

[0045] Explanation of reference signs:

[0046] 1, fan assembly; 10, fan; 100, volute assembly; 101, air inlet; 102, air outlet; 103, mounting opening; 104, opening; 110, volute body; 111, welding portion; 112, flange; 120, cover plate; 121, plate body; 122, protruding portion; 122a, first protruding sub-portion; 122b, second protruding sub-portion; 123, fitting portion; 124, positioning portion; 130, insert; 131, welding groove; 132, fastening portion; 140, volute tongue; 141, volute tongue gap; 200, impeller; 210, hub; 220, blade; 201, accommodating groove; 230, blade disc; 300, connecting assembly; 310, insert; 311, insert body; 312, embedded portion; 313, reinforcing portion; 320, connecting piece; 321, connecting frame; 322, connecting portion; 322a, connecting sub-portion; 322b, folded sub-portion; 323, clamping portion; 324, flange; 330, clamping piece; 20, driving motor; 21, stator assembly; 22, rotor assembly; 22a, rotating shaft; 22b, rotor core; 22c, first bearing; 22d, second bearing; 23, end cover; 23a, end portion; 23b, limiting portion; 23c, abutting portion.

[0047] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. Embodiments of the present application

[0048] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0049] It should be noted that if the present application involves directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0050] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, if "and / or" or "and / or" appears throughout the text, it means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor in the protection scope claimed by the present application.

[0051] The present application provides a fan, which aims to reduce the noise of the fan. For the convenience of understanding and description, in the drawings 1 to 25 of the present application, the space, slot or hole is indicated by solid arrow. The following are several industry professional terms related to the present case:

[0052] Volute tongue gap: the distance between the volute tongue and the outer edge of the impeller of the centrifugal fan; Outlet height of the impeller: the vertical distance from the outlet edge of the blade to the central axis of the impeller; For multi-layer impeller, the outlet height of the impeller is the sum of the vertical distance from the outlet edge of any blade in each blade group to the central axis of the impeller; Outlet height of the volute: the cross-sectional height at the outlet of the volute, that is, the height in the axial direction of the outlet of the volute.

[0053] Please refer to FIG. 4 and 11, in an embodiment of the present application, the fan 10 includes a volute assembly 100 and an impeller 200, the volute assembly 100 has a fan cavity, and an air inlet 101 and an air outlet 102 communicating with the fan cavity, the volute includes a volute tongue 140 corresponding to the air outlet 102; The impeller 200 is arranged in the fan cavity, the impeller 200 includes at least two layers of blade groups arranged in the axial direction, each layer of blades 220 includes a plurality of blades 220 arranged in the circumferential direction of the impeller 200, the blades 220 of the adjacent two layers of blade groups are arranged in staggered manner, and the volute tongue gap 141 between the volute tongue 140 and the impeller 200 is arranged in non-equal distance in the axial direction of the volute assembly 100.

[0054] The structure of the fan 10 will be described in detail below.

[0055] Regarding the fan 10, the fan 10 is generally a centrifugal fan 10, the fan 10 mainly comprises a volute assembly 100 and an impeller 200, the impeller 200 is arranged in the volute assembly 100. Generally speaking, the volute assembly 100 comprises a volute body 110 and a cover plate 120, the volute body 110 generally comprises a bottom plate and a surrounding plate, the bottom plate and the surrounding plate can be integrally formed or separately arranged, in an embodiment, the bottom plate and the surrounding plate are integrally formed, the shape of the volute assembly 100 is determined by the profile of the surrounding plate. The volute body 110 is configured to form an air inlet 101, an air outlet 102 and a mounting port 103, the cover plate 120 is used to cover the mounting port 103, the volute body 110 and the cover plate 120 form a fan cavity, the air inlet 101 and the air outlet 102 are both communicated with the fan cavity. The main function of the air inlet 101 is to guide the fluid (gas or liquid) into the impeller 200. It is usually designed to be smooth in shape to reduce flow resistance and pressure loss; the main function of the air outlet 102 is to guide the fluid to leave the volute assembly 100, usually after the fluid passes through the impeller 200 and converts kinetic energy into pressure energy in the volute assembly 100; the main function of the mounting port 103 is to mount the impeller 200 into the fan cavity. In an embodiment, in order to facilitate the installation of the impeller 200 and the volute body 110, the above-mentioned mounting port 103 is usually open, of course, in other embodiments, the mounting port 103 can be non-open.

[0056] Regarding the impeller 200, the main structure of the impeller 200 generally comprises a blade disc, a hub 210 and a blade 220, the hub 210 is drivingly connected with the rotor assembly 22. The blade disc is a component connecting the blade 220 and the shaft, usually made of stainless steel or aluminum alloy, its function is to fix the blade 220 and the hub 210 so that they can rotate together; the blade 220 is the main structural component of the impeller 200, responsible for converting energy into fluid kinetic or static energy, according to the different structures of the blade 220 and the fluid characteristics, it can be divided into straight blades 220, twisted blades 220 and blades 220 limited to static pressure; the hub 210 is the central part of the impeller 200, bearing the blade 220 and the blade disc, responsible for transmitting the rotating force to the shaft. In order to improve the strength and stiffness of the hub 210, in the embodiment, the impeller 200 is a multi-layer impeller 200, including but not limited to double-layer, three-layer or four-layer and more than four layers. Each layer of the impeller 200 comprises a group of blades 220.

[0057] The following is introduced by taking the double-layer impeller 200 as an example. The impeller 200 includes the first, second and third impeller discs 230 coaxially arranged in sequence along a certain direction, the two ends of a blade group are connected to the first and second impeller discs 230 respectively, and the two ends of a blade assembly are connected to the second and third impeller discs 230 respectively. In the two-layer blade group, the staggered arrangement of the blades 220 mainly includes axial staggering, radial staggering, angular staggering or composite staggering. The axial staggering refers to that the two groups of blades 220 are staggered by a certain distance in the axial direction (along the direction of the rotating shaft). The radial staggering refers to that the two groups of blades 220 are staggered by a certain distance in the radial direction (perpendicular to the direction of the rotating shaft). The angular staggering refers to that the two groups of blades 220 are staggered in angle, that is, the installation angles of the two groups of blades are different. The composite staggering refers to that the two groups of blades 220 are staggered in the axial, radial and angular directions in combination with the above-mentioned various staggering modes.

[0058] Regarding the volute tongue 140 and the volute tongue gap 141, the volute tongue 140 is a part of the volute, which is located at the outlet of the volute and usually plays a role in guiding and accelerating the fluid. The volute tongue gap 141 (also referred to as the volute tongue 140 spacing or the volute tongue gap 141 distance) refers to the distance between the volute tongue 140 of the volute in the centrifugal fan 10 or the centrifugal pump and the outer edge of the impeller 200.

[0059] Regarding the volute tongue gap 141 between the volute tongue 140 and the impeller 200, the volute tongue gap 141 is non-equidistantly arranged in the axial direction of the volute, for example, in the axial direction of the volute, the size of the volute tongue gap 141 changes in a gradually increasing trend, that is, including gradually increasing or stepwise increasing, etc. Alternatively, in the axial direction of the volute, the size of the volute tongue gap 141 changes in a gradually decreasing trend, that is, including gradually decreasing or stepwise decreasing, etc. Exemplarily, in the axial direction of the volute assembly 100, the volute tongue gap 141 gradually increases or gradually decreases from one end of the volute assembly 100 to the other end. Alternatively, the volute assembly 100 has two ends oppositely arranged along the axial direction thereof, and the volute tongue gap 141 gradually decreases from the two ends of the volute assembly 100 to the middle. In an embodiment, in the axial direction of the volute assembly 100, the volute tongue gap 141 corresponding to the central position of the volute tongue 140 is the smallest. By setting the minimum value of the volute tongue gap 141 at the middle of the volute tongue 140, a more uniform pressure distribution can be formed inside the volute, avoiding local high or low pressure areas. Thus, the asymmetric force acting on the impeller 200 is reduced, thereby prolonging the service life of the equipment.

[0060] To verify the technical effects achieved by the fan 10 of the present embodiment, under the same number of blades 220 and working conditions, the fan 10 of the present application and the conventional fan 10 are tested respectively, and the following is the process of the experiment:

[0061] Among them, the processing of volute tongue 140 type line often has a greater impact on the air volume noise result of the fan 10. The inner side profile at the volute tongue 140 of the fan 10 adopts a processing mode of different diameter right-angled fillets, and the inner side profile at the volute tongue 140 can be a straight-angled fillet or a plurality of straight-angled fillets. The radius of the fillet is defined as rwi (where i is a natural number), and the length of the fillet radius is specified. The variable radius point position is defined to form an inclined volute tongue 140, and a parallel plane is drawn through the variable radius point parallel to the volute inlet face plane, and the radial distance between the parallel plane and the volute inlet face is defined as Li (where i is a natural number). For each segment of the fillet, there are two parameters rwi and Li to constrain.

[0062] A 60W power is adopted, and three measurement schemes are set as follows:

[0063] Scheme one: rw1 is 4mm, L1 is 0mm (i.e. the fillet radius is consistent, and there is no variable radius point);

[0064] Scheme two: rw1 is 8mm, L1 is 0mm, rw2 is 4mm, and L2 is 55mm (i.e. the radius of the volute tongue 140 at the volute inlet 101 face position is 8mm, the radius of the volute tongue 140 at the volute bottom surface position is 4mm, and the radius of the volute tongue 140 gradually increases from the inlet face to the bottom surface);

[0065] Scheme three: rw1 is 4mm, L1 is 0mm, rw2 is 8mm, L2 is 38.6mm, rw3 is 4mm, and L3 is 55mm (i.e. the radius of the volute tongue 140 at the volute inlet 101 face and the bottom surface is 4mm, and the radius at the middle position is maximum 8mm, and the radius gradually decreases from the middle position to the two end surfaces);

[0066] The actual characteristic curve of the fan 10, the noise value at the inlet 101, and the noise value at the outlet 102 are measured respectively, and the experimental data is displayed in the form of a chart, and the summary chart is shown in FIGS. 23-25. From the experimental data of FIGS. 23-25, it can be observed that the overall effect of the variable radius volute tongue 140 is better than that of the consistent fillet volute tongue 140. The volute tongue 140 of scheme three has a significant advantage in flow rate at low pressure (471Pa).

[0067] To further verify the results, relevant simulation experiments were also conducted, please refer to FIG. 14 to FIG. 16. FIG. 14 is a different cross-section velocity vector distribution diagram of a straight volute tongue 140 with equidistantly arranged volute tongue gaps 141 in the axial direction of the volute, wherein (a) is at the center plane of the volute, (b) is near the bottom end cross-section, and the distance is 0.02 m, and (c) is near the volute inlet 101 cross-section, and the distance is 0.02 m. FIG. 15 is a different cross-section velocity vector distribution diagram of a single-sided inclined volute tongue 140 with non-equidistantly arranged volute tongue gaps 141 in the axial direction of the volute, wherein (a) is at the center plane of the volute, (b) is near the bottom end cross-section, and the distance is 0.02 m, and (c) is near the volute inlet 101 cross-section, and the distance is 0.02 m. FIG. 16 is a different cross-section velocity vector distribution diagram of a double-sided inclined volute tongue 140 with non-equidistantly arranged volute tongue gaps 141 in the axial direction of the volute, wherein (a) is at the center plane of the volute, (b) is near the bottom end cross-section, and the distance is 0.02 m, and (c) is near the volute inlet 101 cross-section, and the distance is 0.02 m.

[0068] In the axial direction of the volute, the volute tongue gap 141 is constant for the straight volute tongue 140, the volute tongue gap 141 gradually increases or the volute tongue gap 141 gradually decreases for the single-sided inclined volute tongue 140, and the volute tongue 140 has two ends arranged oppositely along the axial direction. The volute tongue 140 with the volute tongue gap 141 gradually decreasing from the two ends of the volute tongue 140 to the middle is the double-sided inclined volute tongue 140. From the above experimental results, as shown in FIG. 14, under low pressure, a large proportion of airflow is radially incident to the wall surface of the volute tongue 140 at the front cross-section (near the volute inlet 101 cross-section, FIG. c), the middle cross-section (at the center plane of the volute, FIG. a), and the rear cross-section (near the bottom end cross-section, FIG. b), causing certain loss. As shown in FIG. 15, the radial incident airflow of the circumferential wall surface of the volute tongue 140 is obviously reduced. For the single-sided inclined volute tongue 140, the diameter of the volute tongue 140 gradually increases from the rear side to the front side of the impeller 200. The greater the range of the diameter change of the volute tongue 140, the easier it is to form a local high-speed area between the volute and the impeller 200 below the volute tongue 140, causing part of the static pressure loss. In contrast, as shown in FIG. 16, the double-sided inclined volute tongue 140 reduces the loss caused by the direct impact of high-speed airflow on the corner wall surface of the volute tongue 140, and controls the maximum speed of the high-speed area formed by the diameter increase of both sides, becoming the optimal design scheme with the smallest loss.

[0069] The technical scheme of the application can effectively break and disperse the vortex structure of the air flow, change the air flow path, and make the air flow pass through the impeller 200 more smoothly, thereby reducing the formation and intensity of the vortex, and thus reducing the vortex noise. In addition, the technical scheme of the application sets the axial volute tongue gap 141 as a non-equidistant gap, thereby changing the air flow direction, reducing the formation of vortex and turbulence, making the air flow more stable, and thus reducing the noise.

[0070] In another embodiment, in order to improve the wind resistance of the impeller 200, the outlet height of the impeller 200 is the sum of the vertical distances from the outlet edges of any blade 220 in each blade group to the central axis of the impeller 200, and the ratio between the outlet height of the impeller 200 and the outer diameter of the impeller 200 is a width-diameter ratio, which is not less than 0.4 and not greater than 0.6.

[0071] To verify the technical effects achieved by the fan 10 of the embodiment, under the same number of blades 220 and working conditions, the fan 10 of the application and the conventional fan 10 are tested respectively, and the following is the process of the experiment:

[0072] Since the outer diameter of the impeller 200 and the outlet height of the impeller 200 jointly determine the shape of the impeller 200, the outer diameter of the impeller 200 is set as D2, the outlet height of the impeller 200 is set as b2, and a dimensionless profile shape parameter is defined:

[0073] For example, taking a single-layer impeller 200, the outlet height of the impeller 200 is the vertical distance from the outlet edge of the blade 220 to the central axis of the impeller 200, and if it is double-layer, the outlet height of the impeller 200 is the sum of the vertical distances from the outlet edges of any blades 220 in each blade group to the central axis of the impeller 200. As shown in FIG. 11, the outlet height b2 of the impeller 200 is the sum of the outlet height b21 of the one-layer blade group and the outlet height b22 of the two-layer blade group. For a volute with a determined profile, a 30W power is adopted, and three measurement schemes are set as follows:

[0074] Scheme one: D2 is 82.5mm, b2 is 42.8mm;

[0075] Scheme two: D2 is 85mm, b2 is 42.8mm;

[0076] Scheme three: D2 is 87.5mm, b2 is 42.8mm;

[0077] That is, the width-diameter ratios are 0.519, 0.506, and 0.439 respectively, and the range of the width-diameter ratio is limited to 0.4-0.6. The actual characteristic curves of the fan 10 are measured respectively, and compared with the original prototype. The summary chart obtained from the experimental data of the above three schemes is shown in FIG. 22.

[0078] From the experimental data of FIG. 22, it can be observed that, in the case of equal air volume, the smaller the profile form parameter is, the greater the maximum static pressure that can be achieved. For this volute, the impeller 200 with D2 of 82.5 mm (Scheme One) cannot achieve the ideal outlet static pressure. In terms of flow rate, the impeller 200 with D2 of 85 mm and b2 of 42.8 mm, i.e., a width-diameter ratio of 0.439, has a better overall level.

[0079] In the design of the fan 10, the higher the static pressure is, the stronger the system's ability to overcome resistance is. To further verify this result, relevant simulation experiments were also conducted, as shown in FIGS. 17 to 19. As shown in FIG. 17, the static pressure increases with the decrease of the profile coefficient, and reaches a maximum near the outer wall of the volute. Near the outlet of the impeller 200, the static pressure fluctuates greatly. The larger the diameter of the impeller 200 is, the smaller the profile form parameter is, and the relatively higher the static pressure in the entire flow field is, and the proportion of the static pressure in the total pressure increases, reducing the energy loss in the volute and in the pipe after the gas leaves the fan 10. Therefore, the impeller 200 with D2 of 82.5 mm and b2 of 42.8 mm in Scheme One cannot meet the outlet static pressure requirement.

[0080] For the side of the impeller 200 away from the air inlet 101, as shown in FIGS. 18 and 19, there is a large low-speed zone at the outlet of the fan 10 volute, indicating that the flow separation at this position is more serious, and the influence of the separation vortex is more significant with the decrease of the profile form parameter, resulting in a decrease in the outlet flow rate. At the same time, the increase in the diameter of the impeller 200 leads to a decrease in the distance between the impeller 200 and the volute, especially near the volute side, a small gap appears. Part of the gas flow that does not flow out smoothly from the outlet cannot enter the flow passage between the volute and the impeller 200 again, which causes a local high-pressure zone at the outlet of the volute, generates a large backflow driving force, and affects the outlet effect of the fan 10.

[0081] Therefore, among the three schemes, the impeller 200 with D2 of 85 mm, b2 of 42.8 mm, and a width-diameter ratio of 0.439 can provide a larger outlet static pressure while maintaining a larger flow rate, and has a better wind resistance.

[0082] In an embodiment, the ratio between the outlet height of the volute assembly 100 and the outer diameter of the impeller 200 is not less than 0.6 and not greater than 0.7. In this embodiment, by optimizing the fluid dynamics performance, reducing noise and vibration, improving pressure and flow characteristics, facilitating design and manufacturing, and wide adaptability, the overall performance and reliability of the centrifugal fan 10 or centrifugal pump can be significantly improved.

[0083] To verify the technical effects achieved by the fan 10 of the present embodiment, under the same number of blades 220 and working condition, the fan 10 of the present application and a conventional fan 10 were tested, and the following is the experimental process:

[0084] Exemplarily, the outlet 102 of the fan 10 is rectangular, and the outlet height of the volute is consistent with the overall height of the volute. The height of the impeller 200 is selected as 42.8 mm according to the above scheme b2. Since the impeller 200 is limited by the position matching of the motor bearing, different outlet heights B represent the distance difference between the impeller 200 and the wall surface of the inlet 101 of the volute. The diameter of the impeller 200 is selected as 85 mm according to the above scheme D2. The diameter of the impeller 200 and the outlet height of the volute jointly affect the aerodynamic performance of the fan 10. Assuming that the outer diameter of the impeller 200 is D2 and the height of the volute is B, a dimensionless position matching parameter is defined as follows:

[0085] A 60W power is adopted, and three measurement schemes are set as follows:

[0086] Scheme one: B is 52 mm, and D2 is 85 mm;

[0087] Scheme two: B is 55 mm, and D2 is 85 mm;

[0088] Scheme three: B is 58 mm, and D2 is 85 mm;

[0089] That is, the ratio of the height B of the volute to the outer diameter D2 of the impeller 200 is 0.61, 0.65, and 0.68 respectively, and the ratio of the height B of the volute to the outer diameter D2 of the impeller 200 is limited in the range of 0.6-0.7. The actual characteristic curves of the fan 10 are measured respectively, and compared with the original prototype. The summary chart obtained from the experimental data of the above three schemes is shown in FIG. 21.

[0090] It can be observed from the experimental data that the volute with the height B of 55 mm, the outer diameter D2 of 85 mm, and the ratio of the height B of the volute to the outer diameter D2 of the impeller 200 of 0.65 has a significant advantage in the flow rate in the low pressure area. The air volume under each working condition first increases and then decreases with the increase of the outlet height B, and therefore, the optimal matching height of the volute under the diameter of the impeller 200 can be evaluated.

[0091] In order to further verify the result, a related simulation experiment is also performed, and the working point of the outlet static pressure P is selected as 0 Pa. The simulation result is shown in FIG. 20. It can be seen from FIG. 20 that the volute is too low, which causes a large separation vortex to be formed on the upper end of the impeller 200, thereby hindering the airflow to flow through the gap of the impeller 200. If the volute is too high, a large airflow will be deflected when entering the rotating domain of the impeller 200, and the deflection will be large, which will be deflected to the position close to the outlet, and the air inlet on the other side will be small, thereby limiting the overall utilization rate of the impeller 200. At the same time, a relatively obvious speed separation vortex is formed at the position of the blade 220, which hinders the airflow to pass through the blade 220, and seriously affects the overall airflow field of the fan 10. Therefore, among the above three schemes, the volute with the height B of 55 mm and the ratio of 0.65 has a high utilization rate and a relatively smooth flow field.

[0092] In an embodiment, referring to FIG. 11, in order to ensure that the fan 10 has sufficient air intake, the clearance between the inner wall of the air inlet 101 side of the volute assembly 100 and the impeller 200 is not less than 3 mm and not more than 6 mm. That is, in FIG. 11, the clearance at A is not less than 3 mm and not more than 6 mm, and can be specifically 3 mm, 4 mm, 5 mm, or 6 mm. In this way, within this range, better air intake can be achieved while reducing airflow backflow.

[0093] The present application also proposes a fan assembly 1, which can be applied to water heaters (especially gas water heaters), range hoods, air treatment devices, and the like, which will not be exemplified one by one here. The specific structure of the fan assembly 1 will be described below.

[0094] Referring to FIGS. 3 and 4, in an embodiment of the present application, the fan assembly 1 includes a fan 10 and a driving motor 20, the fan 10 includes a volute assembly 100 and an impeller 200 arranged in the volute assembly 100, and the driving motor 20 includes a stator assembly 21 and a rotor assembly 22 arranged in the stator assembly 21, the volute assembly 100 and the stator assembly 21 are integrally formed, and the rotor assembly 22 is drivingly connected to the impeller 200.

[0095] Regarding the driving motor 20, the driving motor 20 generally includes a motor housing, a stator assembly 21, and a rotor assembly 22, the motor housing is used to protect the internal components such as the stator assembly 21 and the rotor assembly 22, and provides mechanical support. In the present embodiment, by integrally forming the stator assembly 21 with the volute assembly 100, the motor housing, the connecting structure of the motor housing and the stator assembly 21, and the connecting structure of the motor housing and the volute assembly 100 are reduced, thereby simplifying the installation structure of the driving motor 20 in the fan assembly 1.

[0096] Regarding the integrally formed volute assembly 100 and stator assembly 21, the volute assembly 100 and the stator assembly 21 are integrally formed, the volute assembly 100 includes a volute main body 110 and a cover plate 120, and the volute main body 110 generally includes a bottom plate and a surrounding plate. Therefore, the integrally formed volute assembly 100 and stator assembly 21 can be integrally formed with the cover plate 120 or the bottom plate. In addition, in some special embodiments, the stator assembly 21 can also be integrally formed with the surrounding plate. In an embodiment, in order to reasonably arrange the structure arrangement of the fan assembly 1, the stator assembly 21 is integrally formed with the cover plate 120.

[0097] It should be understood that in the present embodiment, the integrated arrangement of the volute assembly 100 and the stator assembly 21 is intended to achieve the manufacture of a whole structure by a single machining or a combination of various machining methods, avoiding the defects caused by the traditional assembly or welding of the volute assembly 100 and the stator assembly 21. The integrated arrangement of the volute assembly 100 and the stator assembly 21 includes but is not limited to injection molding and 3D printing, etc.

[0098] The technical solution of the present application integrates the stator assembly 21 of the driving motor 20 and the volute assembly 100 of the fan 10, so that the driving motor 20 does not need to be fixed and installed by screws or other connecting parts 322, thereby simplifying the installation structure of the driving motor 20 in the fan assembly 1.

[0099] Further, the integrated arrangement of the stator assembly 21 and the volute assembly 100 has significant advantages in many applications, including reducing weight, improving structural rigidity, simplifying manufacturing and assembly processes, and system reliability, etc.

[0100] For example, referring to FIGS. 4 and 9, in an exemplary embodiment, the volute assembly 100 includes a volute body 110 and a cover plate 120, the volute body 110 and the cover plate 120 enclose a fan cavity for installing the impeller 200, and the cover plate 120 and the stator assembly 21 are integrally arranged.

[0101] Further, the cover plate 120 includes a plate body 121 and a protruding portion 122 provided on the plate body 121, the plate body 121 and the volute body 110 enclose the fan cavity; the protruding portion 122 is arranged in a ring shape, the protruding portion 122 covers and is integrally arranged with the stator assembly 21, and the protruding portion 122 encloses a motor cavity for installing the rotor assembly 22. In an embodiment, in order to further reduce the axial height of the fan assembly 1, at least part of the protruding portion 122 is arranged in the fan cavity.

[0102] At least part of the protruding portion 122 is arranged in the fan cavity. Since the protruding portion 122 surrounds the motor cavity for mounting the rotor assembly 22, that is, part of the driving motor 20 is located in the fan cavity, thereby reducing the axial height of the fan assembly 1, which generally refers to the axial height of the fan assembly 1 relative to the shaft 22a of the driving motor 20. At least part of the protruding portion 122 is arranged in the fan cavity, which can be understood as all of the protruding portion 122 being arranged in the fan cavity, or part of the protruding portion 122 being arranged in the fan cavity. The part of the protruding portion 122 can be arranged in the axial direction of the shaft 22a of the driving motor 20, which can be one-half of the protruding portion 122 arranged in the fan cavity, or one-third of the protruding portion 122 arranged in the fan cavity, and so on. Of course, other proportions can also be used, for example, the motor cavity generally includes a first bearing cavity, a main cavity, and a second bearing cavity. In this case, the protruding portion 122 corresponding to the first bearing cavity can be arranged in the fan cavity.

[0103] In an exemplary embodiment, referring to FIGS. 15 and 16, the protruding portion 122 includes a first protruding sub-portion 122a and a second protruding sub-portion 122b, which are arranged on opposite sides of the plate body 121. The first protruding sub-portion 122a is arranged close to the impeller 200, and the second protruding sub-portion 122b is arranged away from the impeller 200. The first protruding sub-portion 122a is arranged in the receiving groove 201, and the second protruding sub-portion 122b covers the stator assembly 21.

[0104] In another exemplary embodiment, referring to FIGS. 7 and 9, the rotor assembly 22 includes a shaft 22a, a rotor core 22b, a first bearing 22c, and a second bearing 22d. The first bearing 22c, the rotor core 22b, and the second bearing 22d are arranged in sequence along the axial direction of the shaft 22a. The first protruding sub-portion 122a defines a first bearing cavity for mounting the first bearing 22c, the second protruding sub-portion 122b defines a main cavity for mounting the rotor core 22b, and the end cover 23 defines a second bearing cavity for mounting the second bearing 22d. The first bearing cavity, the main cavity, and the second bearing cavity are connected to form a motor cavity.

[0105] In an embodiment, in order to shorten the length of the shaft 22a of the rotor assembly 22, the impeller 200 has a first end and a second end arranged opposite to each other. The first end is arranged close to the cover plate 120, and the hub 210 is arranged at the first end of the impeller 200.

[0106] In another embodiment, referring to FIGS. 3 and 4, FIGS. 7 and 9, in order to further shorten the length of the shaft 22a of the rotor assembly 22, the hub 210 arranged close to one side of the cover plate 120 is provided with a receiving groove 201, and at least part of the protruding portion 122 is arranged in the receiving groove 201.

[0107] In yet another embodiment, the protrusion 122 is provided with an opening 104 at one end away from the plate body 121, the opening 104 is in communication with the motor cavity, the driving motor 20 comprises an end cover 23, the end cover 23 is used to cover the opening 104; in order to facilitate the disassembly of the rotor assembly 22, the end cover 23 and the protrusion 122 are detachably connected.

[0108] In another embodiment, in order to ensure that the end cover 23 and the protrusion 122 are connected with good reliability and good sealing, the end cover 23 and the protrusion 122 are riveted and pressed. In this embodiment, the end cover 23 and the protrusion 122 are riveted and pressed, which can be understood as interference fit connection between the end cover 23 and the protrusion 122. Wherein, the riveting and pressing connection between the end cover 23 and the protrusion 122 makes the fan assembly 1 not affected by environmental factors (such as temperature, humidity, vibration, etc.), has good fatigue resistance and shock resistance, is suitable for long-term use structure, and is suitable for use in scenarios such as water heaters.

[0109] Further, the protrusion 122 is provided with a limiting step on the inner wall thereof near the opening 104, the limiting step comprises a horizontal step surface and a vertical step surface connected with each other; the end cover 23 comprises an end portion 23a, a limiting portion 23b and an abutting portion 23c connected in sequence, the end portion 23a constitutes a second bearing cavity; the limiting portion 23b is in limiting abutment with the horizontal step surface of the limiting step, and the abutting portion 23c is in abutment with the vertical step surface of the limiting step. In this way, the horizontal step surface is arranged to limit the connection position of the end cover 23 and the protrusion 122, so that they cannot be inserted into the motor cavity too much. The vertical step surface is used for abutting with the abutting portion 23c, that is, the abutting portion 23c and the protrusion 122 are interference fit at the vertical step surface.

[0110] It can be understood that the horizontal step surface refers to the surface of the protrusion 122 at the position of the opening 104, which is perpendicular to the axis of the rotating shaft 22a of the driving motor 20, and the vertical step surface refers to the surface of the protrusion 122 at the position of the opening 104, which is parallel to the axis of the rotating shaft 22a of the driving motor 20.

[0111] It is worth mentioning that there are many ways to install the volute body 110 and the cover plate 120, such as welding or adhesive connection, or pin and buckle connection, etc.

[0112] However, since the strength of the welding portion 111 is usually lower than that of the base material, and the cover plate 120 is usually used to install the impeller 200 and the components of the motor, if the welding quality at the connection between the cover plate 120 and the volute body 110 is not good, it may become a weak link of the structure, thereby affecting the stability of the structure of the cover plate 120 and the volute body 110.

[0113] In an embodiment, the volute assembly 100 comprises a volute body 110, a cover plate 120 and an insert 130, the volute body 110 has a mounting opening 103; the cover plate 120 is used to cover the mounting opening 103; the insert 130 is integrally formed with the cover plate 120, and the insert 130 is welded or bonded with the volute body 110.

[0114] In the embodiment, in order to reduce the weight of the fan assembly 1 and reduce the manufacturing cost, the materials of the volute body 110 and the cover plate 120 are generally plastic.

[0115] Since the cover plate 120 is integrally formed with the stator assembly 21, the material of the cover plate 120 needs to have good insulation performance and arc resistance. Therefore, the material of the cover plate 120 is generally BMC material, which is a composite material. Of course, the materials of the plate body 121 and the protruding part 122 can also be other materials similar to BMC material, such as SMC (Sheet Molding Compound) material, SMC / BMC mixed composite material, or DMC (Dough Molding Compound) material, etc., which will not be listed one by one. The BMC material has high cost and is not easy to demold, and the volute body 110 does not need good insulation performance and arc resistance, so the material of the volute body 110 is generally ordinary plastic.

[0116] Since the volute body 110 and the cover plate 120 need to use different materials. Different materials have different melting points. In the welding process, one material may have melted while the other material has not reached the melting point, which will cause uneven welding and form a weak joint, thereby causing the problem of poor connection stability between the volute body 110 and the cover plate 120. In the embodiment, the material of the insert 130 is the same as that of the volute body 110, and the insert 130 is integrally formed with the cover plate 120. Therefore, the problem of poor connection stability caused by the difference between the materials of the cover plate 120 and the volute body 110 can be solved.

[0117] Regarding the integrally formed setting of the insert 130 and the cover plate 120, the integrally formed setting of the insert 130 and the cover plate 120 includes but is not limited to injection molding and 3D printing, etc. In an embodiment, the insert 130 and the cover plate 120 are integrally injection molded.

[0118] As to the welding connection or bonding between the insert 130 and the volute body 110, the bonding between the insert 130 and the volute body 110 generally refers to the adhesive bonding. In this way, the insert 130 and the volute body 110 can distribute the stress on a larger contact area, reducing the local stress concentration and reducing the risk of material fatigue and fracture. Secondly, it can also provide excellent sealing performance to prevent fluid leakage. In addition, the adhesive bonding process is relatively simple and does not require complex equipment and processes, reducing processing costs and time. The insert 130 and the volute body 110 are connected by welding, wherein the welding connection is usually ultrasonic welding or laser welding, etc. In this way, the welding between the insert 130 and the volute body 110 can provide a high-strength permanent connection, and the welding joint can usually withstand high-temperature environments and is suitable for equipment operating in high-temperature conditions.

[0119] In the above, whether the insert 130 and the volute body 110 are connected by adhesive bonding or welding should be determined according to the specific application requirements and conditions. If the power required by the scene where the fan assembly 1 is applied is large and the operating scene is high temperature, welding is a better choice. If the scene where the fan assembly 1 is applied requires good sealing, corrosion resistance, and shock absorption and noise reduction effects, and the operating conditions do not allow high temperature, adhesive bonding may be more suitable.

[0120] In this way, the present embodiment connects the volute body 110 and the cover plate 120 by the insert 130, and the insert 130 is integrally formed with the cover plate 120. The insert 130 is connected to the volute body 110 by welding or bonding. When the insert 130 is connected to the volute body 110 by welding, the insert 130 is made of a material with higher strength, thereby ensuring the stability of the structure of the cover plate 120 and the volute body 110. When the insert 130 is connected to the volute body 110 by bonding, the insert 130 can be made of a material suitable for bonding, thereby ensuring the tightness and stability of the connection between the cover plate 120 and the volute body 110. The provision of the insert 130 also makes the application range of the volute assembly 100 more extensive.

[0121] In a preferred embodiment, referring to FIGS. 7 and 8, the volute body 110 has a first bonding surface that is bonded to the insert 130 and the cover plate 120. The volute body 110 is provided with a welding portion 111 on the first bonding surface, and the insert 130 is provided with a welding groove 131 that is adapted to be installed on the welding portion 111. Alternatively, the volute body 110 is provided with a welding groove 131 on the first bonding surface, and the insert 130 is provided with a welding portion 111 that is adapted to be installed on the welding groove 131. The welding groove 131 is usually a ring-shaped groove surrounding the mounting port 103. In an embodiment, the number of welding grooves 131 is multiple, and the multiple welding grooves 131 are arranged side by side. The number of welding grooves 131 can be two, three, four, five, six, or more than six.

[0122] In an embodiment, referring to FIG. 9 and FIG. 11, in order to ensure the stability of the welding between the cover plate 120 and the volute body 110, the insert 130 is annularly arranged around the cover plate 120. In other embodiments, the insert 130 can also be formed by multiple insert segments arranged along the outer periphery of the cover plate 120.

[0123] In an embodiment, referring to FIG. 5 and FIG. 14, the volute body 110 has an air outlet 102 and a mounting hole 103, and in order to ensure the stability of the welding between the cover plate 120 and the volute body 110, the end surface of the insert 130 is flush with the end surface of the air outlet 102.

[0124] In an embodiment, referring to FIG. 2, FIG. 4 and FIG. 9, in order to facilitate the installation and positioning of the cover plate 120 and the volute body 110, the outer periphery of the volute body 110 is provided with a flange 112 near the air outlet 102, and the insert 130 is provided with a avoiding slot corresponding to the position of the flange 112. Alternatively, the cover plate 120 is provided with a avoiding slot corresponding to the position of the flange 112. As shown in FIG. 4, through the arrangement of the flange 112, when the cover plate 120 is installed, the flange 112 can be used as a positioning point, thereby facilitating the installation and positioning of the cover plate 120 and the volute body 110.

[0125] In a preferred embodiment, referring to FIG. 11, the insert 130 is further provided with a fastening part 132, which is integrally formed with the cover plate 120. Through the arrangement of the fastening part 132, after the insert 130 and the cover plate 120 are integrally formed, the connection area between the insert 130 and the cover plate 120 is increased, thereby making the connection between the insert 130 and the cover plate 120 more stable.

[0126] Further, the fastening part 132 is a groove provided on the insert 130, and / or the fastening part 132 is a protrusion provided on the insert 130. The groove and the protrusion can be regular shapes such as cylindrical shape, square column shape, or other irregular shapes, which will not be illustrated one by one here.

[0127] Further, the number of the fastening part 132 is multiple, and the multiple fastening parts 132 are arranged at intervals along the circumference of the insert 130. In an embodiment, the multiple fastening parts 132 are uniformly arranged at intervals along the circumference of the insert 130.

[0128] In another preferred embodiment, in order to facilitate the welding of the insert 130 and the volute body 110, the circumference of the connection between the insert 130 and the volute body 110 is formed with a step. That is, the circumference of the connection between the insert 130 and the volute body 110 is not aligned, thereby making the welding head of the insert 130 and the volute body 110 better positioned.

[0129] In an embodiment, the distance between the peripheral side of the insert 130 and the peripheral side of the volute body 110 is not greater than 5mm and not less than 3mm. Specifically, the distance between the peripheral side of the insert 130 and the peripheral side of the volute body 110 includes, but is not limited to, 3.0mm, 3.2mm, 3.4mm, 3.5mm, 3.6mm, 3.8mm, 4.0mm, 4.2mm, 4.4mm, 4.5mm, 4.6mm, 4.8mm or 5.0mm.

[0130] In yet another embodiment, referring to FIG. 7 and FIG. 8, in order to facilitate the positioning and installation of the cover plate 120 and the volute body 110, and to improve the sealing of the connection between the cover plate 120 and the volute body 110. The cover plate 120 includes a plate body 121, a fitting portion 123 and a positioning portion 124, the fitting portion 123 is arranged around the plate body 121, and the fitting portion 123 is fitted with the end face of the installation port 103 of the volute body 110; the positioning portion 124 is arranged at the connection between the plate body 121 and the fitting portion 123, and the positioning portion 124 is a protrusion towards the side of the volute body 110. Among them, the positioning portion 124 is arranged, so that the cover plate 120 and the volute body 110 are positioned and installed more quickly. The fitting portion 123 is fitted with the first fitting surface and the volute body 110, and the arrangement of the fitting portion 123 and the positioning portion 124 forms a radial seal between the cover plate 120 and the volute body 110, thereby improving the sealing of the connection between the cover plate 120 and the volute body 110.

[0131] In an embodiment, the fan assembly 10 further comprises a connecting assembly 300, which is used to install the volute assembly 100 on an installation carrier. The installation carrier refers to, for example, the support body of a water heater, the support body of an extractor hood, or the support body of an air handling device, etc. Depending on the application scenario of the fan 10, the following will be described taking a water heater as an example.

[0132] Referring to FIG. 4 or FIG. 9, the connecting assembly 300 is arranged at the air outlet 102 of the volute, and the connecting assembly 300 comprises an insert 310 and a connecting piece 320. The insert 310 is integrally formed with the volute, and the connecting piece 320 is connected with the insert 310. The connecting piece 320 is used to connect with the support carrier of the water heater, so as to install the volute on the support carrier of the water heater.

[0133] In the embodiment, the volute generally comprises a volute body 110 and a cover plate 120, and the materials of the volute body 110 and the cover plate 120 are plastic. In order to ensure the strength of the connection between the volute assembly 100 and the mounting carrier, an insert 310 is additionally arranged in the embodiment. The insert 310 generally requires a large strength, and thus the material of the insert 310 is generally selected to be a material with a large strength, such as a metal, for example, carbon steel, stainless steel, alloy steel, and the like. Of course, the insert 310 can also be a non-metal material with a large strength.

[0134] In the embodiment, the insert 310 is arranged at the air outlet, has a strength greater than that of the volute, and is integrally formed with the volute. The volute is connected and mounted with the water heater body at the air outlet 102. Thus, the technical solution of the application improves the structural strength of the air outlet of the volute, thereby improving the stability and reliability of the connection between the volute assembly 100 and the water heater body.

[0135] It can be understood that the connection between a plastic part and a metal part is generally not as firm as the connection between metal parts, especially in the embodiment, the cover plate is also used for mounting the driving motor 20. When the fan assembly 10 is working, the motor will generate vibration or mechanical impact.

[0136] In an exemplary embodiment, the volute comprises a volute body 110 and a cover plate 120. The volute body 110 has a mounting opening 103, and the cover plate 120 is arranged on the mounting opening 103. The insert 310 is embedded in the volute body 110. The volute body 110 is a plastic part, and the insert 310 is a metal part.

[0137] Further, in order to improve the stability of the connection between the insert 310 and the volute body 110, the insert 310 comprises an insert body 311 and an embedding part 312 arranged on the insert body 311. The embedding part 312 is embedded in the volute assembly 100 and integrally formed with the volute assembly 100. Through the arrangement of the embedding part 312, the connection area between the insert 310 and the volute body 110 is increased, thereby improving the stability of the connection between the insert 310 and the volute body 110.

[0138] The embedding part 312 is embedded in the volute assembly 100 from the end face of the air outlet 102. Alternatively, the embedding part 312 is embedded in the volute assembly 100 from the peripheral side of the air outlet 102. In an embodiment, the embedding part 312 is embedded in the volute assembly 100 from the end face of the air outlet 102. At this time, for the embedding part 312 with the same shape and size, the embedding part 312 is embedded in the volute assembly 100 from the end face of the air outlet 102, and the connection area between the embedding part 312 and the volute assembly 100 is the largest.

[0139] Further, in order to further improve the stability of the connection between the insert 310 and the volute body 110, the insert 310 further comprises a reinforcing portion 313, which is arranged on the embedding portion 312. By arranging the reinforcing portion 313, the connection area between the insert 310 and the volute assembly 100 is further increased, thereby further improving the stability of the connection between the insert 310 and the volute body 110. The reinforcing portion 313 can be a protrusion arranged on the embedding portion 312 or a hole arranged on the embedding portion 312. In an embodiment, the embedding portion 312 is arranged in a sheet shape, and the reinforcing portion 313 is a through hole penetrating through the embedding portion 312.

[0140] In another embodiment, the number of the embedding portions 312 is multiple, and the multiple embedding portions 312 are arranged at intervals along the circumference of the insert body 311. In an embodiment, the multiple embedding portions 312 are uniformly arranged at intervals along the circumference of the insert body 311.

[0141] In an exemplary embodiment, referring to FIG. 9, the connecting piece 320 comprises a connecting frame 321, a connecting portion 322 arranged on the connecting frame 321, and a clamping portion 323. The connecting frame 321 and the insert body 311 are connected by fasteners, the connecting portion 322 is used to connect with the mounting carrier by fasteners, and the clamping portion 323 is used to clamp with the mounting carrier. In this way, by arranging the connecting portion 322 and the clamping portion 323, when the fan assembly 1 is installed, the clamping portion 323 is first clamped in position, and then the connecting portion 322 is fixed with the mounting carrier by fasteners. In this way, the installation and positioning of the fan assembly 1 are facilitated, and the stability and tightness of the connection between the fan assembly 1 and the mounting carrier are ensured to a certain extent.

[0142] On the basis of the above embodiment, referring to FIG. 9, the connecting portion 322 comprises a connecting sub-portion 322a and a folded sub-portion 322b connected with each other, the connecting sub-portion 322a is connected with the connecting frame 321, and the folded sub-portion 322b is folded towards one side of the volute assembly 100. In an embodiment, in order to strengthen the connection strength of the connecting piece 320, the connecting frame 321 is further provided with a folded edge 324.

[0143] In an embodiment, the volute assembly 100 has an air inlet 101, and in order to facilitate the installation of the volute assembly 100 and the mounting carrier, the mounting position is arranged on one side of the volute assembly 100 provided with the air inlet 101, and the clamping piece 330 is arranged on the side of the volute assembly 100 away from the air inlet 101. In order to ensure the smoothness of the air inlet, the side of the air inlet 101 usually has less obstructions, and arranging the mounting position on the side of the volute assembly 100 provided with the air inlet 101 can avoid the obstructions of other obstructions to the installation of the volute assembly 100.

[0144] It should be understood that the mounting position can be a mounting slot, a mounting hole, or a mounting column, etc. In an embodiment, the insert 310 is a nut, and of course, in other embodiments, the insert 310 can also be a bolt, a stud, etc. threaded connecting piece 320.

[0145] The application also provides a water heater, which comprises a water heater body and a fan assembly 1. The specific structure of the fan assembly 1 is described above. Since the fan 10 adopts all the technical solutions of the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here.

[0146] Among them, the water heater with the fan assembly 1 is usually a gas water heater, and it is a water heater with forced exhaust function. Its main structure includes a burner, a heat exchanger, a fan assembly 1, a control system and other auxiliary components. The fan assembly 1 is usually installed at the top, bottom or side of the water heater, connected with the combustion chamber and the exhaust system. The specific position design of the fan 10 is related to the structure and model of the water heater. The fan 10 is fixed on the outer shell or internal frame of the water heater by screws, brackets or buckles, etc. to ensure its stability. Air connection: the air inlet of the fan 10 is connected with the combustion chamber to provide air required for combustion; the air outlet is connected with the exhaust pipe to discharge combustion waste gas.

[0147] The above is only an exemplary embodiment of the application, and does not limit the patent scope of the application. Any equivalent structural transformation made by using the content of the application specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the application.

Claims

1. A fan, wherein, The fan comprises: a volute assembly having a fan cavity, and an air inlet and an air outlet communicating with the fan cavity, the volute comprising a volute tongue arranged corresponding to the air outlet; a impeller arranged in the fan cavity, the impeller comprising at least two layers of blade sets arranged in an axial direction, each layer of the blade sets comprising a plurality of blades arranged in a circumferential direction of the impeller, the blades of adjacent two layers of the blade sets being arranged in a staggered manner, and the volute tongue gap between the volute tongue and the impeller being arranged in a non-equidistant manner in the axial direction of the volute assembly.

2. The fan of claim 1, wherein, In the axial direction of the volute assembly, the volute tongue gap gradually increases or gradually decreases from one end of the volute assembly to the other end.

3. The fan of claim 1, wherein, The volute assembly has two ends arranged in opposite directions along the axial direction, and the volute tongue gap gradually decreases from the two ends of the volute assembly to the middle.

4. The fan of claim 3, wherein, In the axial direction of the volute assembly, the volute tongue gap corresponding to the central position of the volute tongue is the smallest.

5. The fan of any one of claims 1 to 4, wherein, The outlet height of the impeller is the sum of the vertical distances from the outlet edges of any blade in each layer of the blade sets to the central axis of the impeller, and the ratio between the outlet height of the impeller and the outer diameter of the impeller is a width-diameter ratio, the width-diameter ratio is not less than 0.4 and not greater than 0.

6.

6. The fan of any one of claims 1 to 5, wherein, The ratio between the outlet height of the volute assembly and the outer diameter of the impeller is not less than 0.6 and not greater than 0.

7.

7. The fan of any one of claims 1 to 6, wherein, The gap between the inner wall of the air inlet side of the volute assembly and the impeller is not less than 3 mm and not greater than 6 mm.

8. The fan of any one of claims 1 to 7, wherein, The volute assembly further comprises a volute body and a cover plate, the volute body has a mounting port, and the cover plate covers the mounting port; The cover plate comprises a plate body and a protruding portion arranged on the plate body, the plate body and the volute body surround the fan cavity; the protruding portion is arranged in a ring shape, the protruding portion covers the stator assembly of the motor, the protruding portion and the stator assembly are arranged in an integral manner, and the protruding portion surrounds a motor cavity for mounting the rotor assembly of the motor.

9. The fan of claim 8, wherein, The volute further comprises an insert, the insert is arranged in an integral manner with the cover plate, and the insert is connected with the volute body.

10. A water heater wherein, The water heater comprises the fan as claimed in any one of claims 1 to 9.

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