Impeller, fan, and air handler

Abstract

An impeller, a fan, and an air handler. The impeller comprises a first end plate, a second end plate and a plurality of blades, wherein the second end plate and the first end plate are sequentially distributed spaced apart in the air intake direction of the impeller, and an air inlet is provided on the second end plate; the plurality of blades are distributed spaced apart in the circumferential direction of the impeller and are connected to the first end plate and the second end plate; the first end plate comprises a first plate portion and a second plate portion arranged around the periphery of the first plate portion, and the second plate portion extends obliquely in the air intake direction in the direction away from the axis of the impeller.

Description

Impellers, fans and air handling units

[0001] This application claims priority to Chinese patent application No. 202310960103.1 filed on August 1, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the technical field of fans, and in particular to an impeller, a fan and an air handling unit. Background Art

[0003] The impeller used in a centrifugal fan usually includes two end plates arranged opposite to each other and a plurality of blades arranged between the two end plates. The end plates are usually arranged in a flat plate structure, which leads to large flow loss and turning loss when the airflow enters the impeller, thereby resulting in low efficiency of the centrifugal fan. Technical issues

[0004] The main purpose of this application is to provide an impeller, aiming to improve the efficiency of the impeller. Technical Solutions

[0005] To achieve the above objectives, the impeller proposed in this application includes:

[0006] A first end plate and a second end plate, wherein the second end plate and the first end plate are sequentially spaced apart along the air inlet direction of the impeller, and the second end plate is provided with an air inlet; and

[0007] A plurality of blades are distributed at intervals along the circumference of the impeller, and the blades connect the first end plate and the second end plate. The first end plate includes a first plate portion and a second plate portion arranged around the periphery of the first plate portion, and the second plate portion extends obliquely in the direction of the air intake in a direction away from the axis of the impeller.

[0008] In one embodiment, a plate surface of the first plate portion is perpendicular to the axis of the impeller.

[0009] In one embodiment, the second end plate includes a third plate portion and a fourth plate portion arranged around a periphery of the third plate portion, and the fourth plate portion extends obliquely in the direction of the air intake in a direction away from the axis of the impeller.

[0010] In one embodiment, a first reference plane is defined as being perpendicular to the axis of the impeller, an angle γ between the second plate portion and the first reference plane is configured to be 10°≤γ≤40°, and / or an angle δ between the fourth plate portion and the first reference plane is configured to be 10°≤δ≤40°.

[0011] In one embodiment, an outer diameter of the first end plate is smaller than an outer diameter of the second end plate.

[0012] In one embodiment, a ratio of an outer diameter of the first end plate to an outer diameter of the second end plate is greater than or equal to 0.7.

[0013] In the radial direction of the air inlet, the dimension between the projection line of the blade on the axial section of the air inlet and the axis of the air inlet gradually decreases along the air inlet direction.

[0014] In one embodiment, the blade has a first end and a second end sequentially distributed in the air inlet direction, and the second end extends outward in the radial direction of the impeller and exceeds the periphery of the first end plate.

[0015] In one embodiment, the trailing edge of the second end portion extends beyond the first end plate in the air intake direction; or, the trailing edge of the second end portion is provided with an outwardly convex transition fillet, and the transition fillet is connected to the edge of the first end plate.

[0016] In the air inlet direction, the trailing edge of the blade extends obliquely away from the rotation direction of the impeller.

[0017] In one embodiment, a second reference plane is defined that passes through the axis of the impeller and the center point of the trailing edge of the blade, and the angle between the trailing edge of the blade and the second reference plane is less than or equal to 45°.

[0018] In one embodiment, the blade has a first end and a second end sequentially distributed in the air inlet direction, and a periphery of the second end plate extends outward in the radial direction of the impeller and exceeds the first end.

[0019] In one embodiment, the outlet installation angle of the blade is less than 90°.

[0020] The present application also proposes a fan, comprising a motor and the aforementioned impeller, wherein the rotating shaft of the motor is arranged on the first end plate of the impeller.

[0021] In one embodiment, the fan also includes a guide cover, which is arranged upstream of the impeller and has a cross-sectional area that gradually decreases in the air intake direction. The guide cover has a diversion end and a guide end distributed in sequence in the air intake direction, and the guide end extends into the air inlet of the second end plate.

[0022] In the radial direction of the impeller, a gap d between the guide end and the edge of the air inlet is configured to be 4 mm ≤ d ≤ 10 mm.

[0023] In one embodiment, the depth H of the guide end extending into the air inlet is configured to be 5mm≤H≤15mm.

[0024] The present application also proposes an air handling unit, comprising the aforementioned impeller, or comprising the aforementioned fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0026] FIG1 is a schematic structural diagram of an impeller according to an embodiment of the present invention;

[0027] FIG2 is a side view of the impeller shown in FIG1 ;

[0028] FIG3 is a cross-sectional view of the impeller shown in FIG1 , wherein the cross-sectional plane passes through the axis of the impeller;

[0029] FIG4 is a cross-sectional view of another embodiment of the impeller of the present application, wherein the cross-sectional plane passes through the axis of the impeller;

[0030] FIG5 is a schematic structural diagram of another embodiment of the impeller of the present application;

[0031] FIG6 is a side view of the impeller shown in FIG5 ;

[0032] FIG7 is a schematic structural diagram of an embodiment of a blower according to the present application;

[0033] FIG8 is a cross-sectional view of the fan shown in FIG7 , with the cross-sectional plane passing through the axis of the impeller;

[0034] FIG9 is a schematic structural diagram of an air handling unit according to an embodiment of the present application;

[0035] FIG10 is a schematic diagram of the internal structure of the air handling unit shown in FIG9;

[0036] FIG11 is a comparison diagram of the required rotational speeds of the impeller of the present application and an impeller of equal diameter at the same efficiency and air volume;

[0037] FIG12 is a diagram comparing the efficiency of a fan using the impeller of the present application and a fan using a traditional impeller.

[0038] Description of Figure Numbers:

[0039] Reference numerals Reference numerals 10 impeller 131 first end portion 11 first end plate 132 second end portion 11a mounting hole 133 leading edge 111 first plate portion 134 trailing edge 112 second plate portion 135 transition fillet 12 second end plate 21 rotating shaft 12a air inlet 22 flange 121 third plate portion 31 air guide cover 122 fourth plate portion 41 air duct 13 blade 42 heat exchanger 13a cross-sectional shape 43 mounting plate

[0040] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. Modes for Carrying Out the Invention

[0041] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0042] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0043] In this application, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0045] This application proposes an impeller, a fan, and an air handling unit, wherein the impeller is applied to the fan, and the fan is applied to the air handling unit. Of course, the fan can also be applied to a ventilation system or other air conditioning systems.

[0046] Please refer to Figures 1 to 6. In some embodiments of the present application, the impeller 10 includes a first end plate 11, a second end plate 12 and a blade group. The second end plate 12 and the first end plate 11 are spaced apart in sequence along the air intake direction of the impeller 10, and the second end plate 12 is provided with an air inlet 12a; the blade group includes a plurality of blades 13 spaced apart along the circumference of the impeller 10, and the blades 13 connect the first end plate 11 and the second end plate 12. The first end plate 11 includes a first plate portion 111 and a second plate portion 112 arranged on the periphery of the first plate portion 111, and the second plate portion 112 extends obliquely in the air intake direction toward a direction away from the axis of the impeller 10.

[0047] In the technical solution of the present application, by improving the structure of the first end plate 11 facing the air inlet 12a, the second plate portion 112 thereof is inclined and extends outward in the air intake direction, which can reduce the turning degree of the air flow flowing in from the air inlet 12a in the impeller 10, thereby reducing the impact loss and turning loss of the air flow energy, and thus improving the efficiency of the impeller 10.

[0048] It should be noted that the circumferential direction of the impeller 10 refers to the circumferential direction around the axis of the impeller 10 , and the radial direction of the impeller 10 refers to any direction radiating from the axis of the impeller 10 to the surroundings on a plane perpendicular to the axis of the impeller 10 .

[0049] In the embodiment of the present application, the outlet installation angle of the blades 13 is less than 90°, that is, the impeller 10 of the present application is configured as a centrifugal impeller 10 with backward blades 13, so that the fan can have higher efficiency and a larger flow rate. Of course, in other embodiments, the outlet installation angle of the blades 13 can also be greater than or equal to 90°, that is, the blades 13 can also be configured as forward blades 13 or radial blades 13.

[0050] Referring to Figures 7 and 8, in one embodiment of the fan of the present application, the fan includes a motor, a shroud 31, and the aforementioned impeller 10. The motor's rotating shaft 21 is mounted on the first end plate 11 of the impeller 10 to drive the first end plate 11 and the entire impeller 10 to rotate. The shroud 31 is located upstream of the impeller 10. The cross-sectional area of ​​the shroud 31 gradually decreases in the air intake direction, and the shroud 31 has a guide end and a guide end sequentially distributed in the air intake direction. The guide end is mounted on the air duct 41 and extends into the air inlet 12a of the second end plate 12, thereby directing air in the air duct 41 upstream of the impeller 10 into the air inlet 12a of the second end plate 12. Of course, in other embodiments, the fan may not be provided with a shroud 31.

[0051] In one embodiment, the first plate portion 111 is provided with a mounting hole 11a, into which the end of the motor shaft 21 extends. A flange 22 is provided on the outer circumference of the shaft 21, which is screwed to the first plate portion 111. This improves the reliability and convenience of installing the motor shaft 21. Of course, in other embodiments, the first end plate 11 may not be provided with the mounting hole 11a, and the motor shaft 21 may be directly fixed to the outer surface of the first end plate 11, or the motor shaft 21 may be fixed to the first end plate 11 by riveting, clamping, or bonding.

[0052] Referring to Figures 3 and 4 , in some embodiments, the surface of the first plate portion 111 is orthogonal to the axis of the impeller 10. Thus, the straight first plate portion 111 and the inclined second plate portion 112 cooperate to effectively guide the airflow flowing in from the air inlet 12a, thereby reducing turning losses without significantly reducing the pressure lift effect of the impeller. It should be noted that orthogonal refers to a vertical or nearly vertical state. Of course, in other embodiments, the first plate portion 111 can also be arranged to extend at an angle like the second plate portion 112.

[0053] Referring to Figures 7 and 8 , in some embodiments, the gap d between the guide end and the edge of the air inlet 12a in the radial direction of the impeller 10 is configured to be 4 mm ≤ d ≤ 10 mm. It will be appreciated that if this gap d is too small, the second end plate 12 is likely to interfere with and collide with the air deflector 31 during its rotation relative to the air deflector 31. If this gap d is too large, air within the air duct 41 is likely to enter the air inlet 12a of the impeller 10 through this gap, creating a significant, unproductive circulating airflow. The gas in this circulating airflow enters the air inlet 12a through this gap, then flows out of the impeller 10, bypasses the second end plate 12, and flows back into this gap, where it re-enters the air inlet 12a. Therefore, by limiting this gap d to less than 10 mm, this unproductive circulating airflow is reduced, thereby improving the efficiency of the impeller 10.

[0054] In some embodiments, the depth H of the guide end extending into the air inlet 12a is configured to be 5 mm ≤ H ≤ 15 mm. It will be appreciated that if the depth H is too small, the clearance between the guide end and the air inlet 12a is too short, resulting in insufficient obstruction to the circulating airflow. If the depth H is too large, the size and volume of the guide end are excessive, resulting in high manufacturing costs.

[0055] Please refer to Figures 9 and 10 together. In one embodiment of the air handling unit of the present application, the air handling unit includes an air duct 41, a heat exchanger 42, and the aforementioned fan, wherein the heat exchanger 42 and the fan are both installed in the air duct 41, and the heat exchanger 42 is located upstream of the fan. The heat exchanger 42 is used to heat or cool the air in the air duct 41. The air guide cover 31 of the fan is fixed to the air duct 41 via a mounting plate 43, and the motor is fixed to the air duct 41 via a mounting bracket. The rotating shaft 21 of the motor extends toward the air guide cover 31 and is equipped with an impeller 10. Of course, in other embodiments, the air handling unit may not be provided with a heat exchanger 42, or the heat exchanger 42 may be located downstream of the fan.

[0056] Furthermore, to meet year-round air conditioning requirements, the air handler can also include at least one component, such as a humidifier or filter. This way, clean air is delivered by the fan to a cooler or heater for cooling or heating to the desired temperature before being delivered to the desired location. Because the air handler primarily processes indoor circulating air, and the use of the aforementioned fan offers high air volume and quality, it is particularly suitable for ventilation in large spaces and high-traffic locations such as computer rooms, shopping malls, exhibition halls, and airports.

[0057] The technical solution of this application, within the constraints of system equipment size, maximizes the load on the impeller 10 and reduces the turning loss of airflow energy. While maintaining the same pressure rise requirement, it is possible to reduce the speed of the impeller 10 as much as possible. This significantly reduces the rotational noise of the impeller 10 and improves efficiency, thereby achieving the goal of a quiet and efficient fan design. Furthermore, the volute-free structural design significantly reduces the noise caused by interference between movement and static, further enhancing the quietness of the entire fan.

[0058] To further improve the efficiency of impeller 10, referring to Figures 1 to 6, in some embodiments, second end plate 12 includes a third plate portion 121 and a fourth plate portion 122 disposed around the periphery of third plate portion 121. Fourth plate portion 122 extends obliquely in the direction of air intake, away from the axis of impeller 10. That is, fourth plate portion 122 extends in the same direction as second plate portion 112, also obliquely extending outward in the direction of air intake. Fourth plate portion 122 guides airflow, working together with second plate portion 112 to direct airflow toward the sides and rear of impeller 10, thereby further reducing impact and turning losses of airflow energy and improving the efficiency of impeller 10. Furthermore, the oblique extension of fourth plate portion 122 reduces the extent of vortexes generated by airflow shedding off the inner wall of fourth plate portion 122, improves the flow field within impeller 10, and thus reduces flow losses of airflow energy.

[0059] In some embodiments, a first reference plane is defined as being perpendicular to the axis of the impeller 10, and an angle γ between the second plate portion 112 and the first reference plane is configured to be 10°≤γ≤40°. That is, the inclination angle of the second plate portion 112 relative to the plane where the air inlet 12a is located is limited. It can be understood that if the inclination angle of the second plate portion 112 is too small, the effect of reducing the degree of turning of the airflow is insufficient, resulting in an insignificant effect in reducing the impact loss and turning loss of the airflow energy; if the inclination angle of the second plate portion 112 is too large, most of the airflow hardly turns and flows out along the axis of the impeller 10, resulting in a weakening of the pressure rise of the airflow when flowing through the impeller 10.

[0060] Referring to Figures 2 and 4 , in some embodiments, the angle δ between the fourth plate portion 122 and the first reference plane is configured to be 10°≤δ≤40°. That is, the inclination angle of the fourth plate portion 122 relative to the plane where the air inlet 12a is located is limited. It can be understood that if the inclination angle of the fourth plate portion 122 is too small, the effect of reducing the degree of airflow turning is insufficient, resulting in an insignificant effect on reducing the impact loss and turning loss of airflow energy; if the inclination angle of the fourth plate portion 122 is too large, most of the airflow hardly turns and flows out along the axis of the impeller 10, resulting in a weakened pressure rise of the airflow when flowing through the impeller 10.

[0061] Referring to Figures 2 and 4 , in one embodiment, the angle δ between the fourth plate portion 122 and the first reference plane is greater than the angle γ between the second plate portion 112 and the first reference plane. That is, along the extension direction of the air outlet passage formed by two adjacent blades 13, the spacing between the second plate portion 112 and the fourth plate portion 122 gradually decreases as it moves away from the axis of the impeller 10. This allows the airflow to be more smoothly directed to the sides and rear of the impeller 10, thereby reducing flow losses and improving the efficiency of the impeller 10. Of course, in other embodiments, the angle δ may be less than or equal to the angle γ.

[0062] Referring to Figures 2 and 4 , to further reduce impact losses of airflow energy, in some embodiments, the outer diameter D1 of the first end plate 11 is smaller than the outer diameter D2 of the second end plate 12. This smaller first end plate 11 can further reduce impact losses and turning losses of airflow energy, thereby improving the efficiency of the impeller 10. Of course, in other embodiments, the outer diameter D1 of the first end plate 11 can also be greater than or equal to the outer diameter D2 of the second end plate 12.

[0063] It should be noted that, in one embodiment, the outer contours of the first and second end plates 11, 12 are both configured to be circular or substantially circular. Therefore, the outer diameters of the first and second end plates 11, 12 refer to the diameters of the circles within which their outer contours lie. Of course, in embodiments where the outer contours of the first and second end plates 11, 12 have other shapes, such as rectangles, polygons, or irregular curves, the outer diameters refer to the diameters of the circumscribed circles tangent to the outer contours. In other words, the orthographic projection of the second end plate 12 on the first reference plane falls within the area of ​​the orthographic projection of the first end plate 11 on the first reference plane.

[0064] In some embodiments, the ratio of the outer diameter D1 of the first end plate 11 to the outer diameter D2 of the second end plate 12 is greater than or equal to 0.7, that is, D1 / D2 ≥ 0.7. It will be appreciated that if the ratio of the outer diameter D1 of the first end plate 11 to the outer diameter D2 of the second end plate 12 is too small, meaning that the first end plate 11 is too small, most of the airflow will flow out along the axis of the impeller 10 without making a turn, resulting in a weaker pressure rise when the airflow passes through the impeller 10.

[0065] In some embodiments, multiple blades 13 are connected between the first end plate 11 and the second end plate 12, and are arranged around the axis of the air inlet 12a, and an air outlet is formed between the first end plate 11 and the second end plate 12. In the axial direction of the air inlet 12a, the diameters of the circles enclosed by the blades 13 are different. When the impeller is applied to the fan, the load of the impeller can be maximized within the size limit of the air duct of the fan, and the speed can be reduced as much as possible while meeting the pressure rise requirement, thereby improving noise and the loss of air flow under the action of the impeller, thereby improving efficiency.

[0066] Specifically, when the impeller is used in a fan, through cooperation with the air duct, the airflow will be transformed from radial flow to flow along the axis of the impeller. Since in the axial direction of the air inlet 12a, the diameters of the circles formed by the blades 13 are not equal, that is, based on the specific structure of the blades 13, the diameters of the circles can be gradually reduced in the direction from the second end plate 12 to the first end plate 11, or the diameters of the circles can first increase and then decrease, or the diameters of the circles can first decrease and then increase. At this time, the impeller formed by the connection between the first end plate 11 and the second end plate 12 is a non-uniform diameter impeller. Such a setting can effectively reduce the rotation speed, improve noise, and effectively reduce losses during turning, thereby improving efficiency.

[0067] The outer diameter of the first end plate 11 is smaller than the outer diameter of the second end plate 12. Since the second end plate 12 can guide the airflow to the blades 13, the first end plate 11 can make the airflow flow to the air outlet along a certain angle and flow out from the air outlet. The setting of this angle not only assists the flow of the airflow, but also facilitates the change of the flow direction when cooperating with the air duct. At the same time, limiting the outer diameter of the second end plate 12 to be larger than the outer diameter of the first end plate 11 facilitates the formation of a bladeless expansion zone between the second end plate 12 and the wall of the air duct, thereby reducing the ineffective work of the airflow passing through the impeller, further improving the static pressure efficiency, and improving the noise.

[0068] Therefore, in the axial direction of the air inlet 12a, the diameters of the circles enclosed by the blades 13 are designed to be unequal, and the outer diameter of the first end plate 11 is set to be smaller than the outer diameter of the second end plate 12. When the impeller is applied to the fan, the load of the impeller can be maximized within the size limit of the fan's air duct, and the speed can be reduced as much as possible while meeting the pressure rise requirement, effectively improving noise and the loss of airflow under the action of the impeller, thereby improving efficiency.

[0069] Referring to Figures 2 and 4 , in the radial direction of the air inlet 12a, the dimension between the projection line of the blade 13 on the axial section of the air inlet 12a and the axis of the air inlet 12a gradually decreases along the air inlet direction. That is, the cross-sectional shape 13a of the blade 13 on the axial section of the impeller 10 extends obliquely toward the axis of the impeller 10 in the air inlet direction. Specifically, in the embodiment shown in Figures 2 and 4 , the axial section of the impeller 10 captures three locations of the blade 13. The cross-sectional shapes 13a of these three blades 13 are all roughly rectangular, and the cross-sectional shape 13a of each blade 13 extends obliquely toward the axis of the impeller 10 in the air inlet direction. This, on the one hand, increases the cross-sectional area of ​​the air outlet channel while maintaining the same dimensions, which is beneficial for converting the kinetic energy of the airflow into static pressure energy, thereby enhancing the pressure lift effect of the impeller 10. On the other hand, in the direction from the second end plate 12 to the first end plate 11, the projection line gradually approaches the axis of the air inlet 12a, or the diameter of the circle enclosed by each blade 13 gradually decreases. At this time, the impeller formed by the connection between the first end plate 11 and the second end plate 12 is a non-uniform diameter impeller, and the limitations such as D2 being less than D1 and 0.7≤D1 / D2<1 are conducive to further reliably reducing the rotation speed, improving noise, reducing losses during turning, and improving efficiency.

[0070] Of course, in other embodiments, the cross-sectional shape 13a of the blade 13 on the axial section of the impeller 10 may extend along the axial direction of the impeller 10, or extend obliquely away from the axial direction of the impeller 10 in the air intake direction.

[0071] In some embodiments, the blades 13 have a first end 131 and a second end 132, which are sequentially distributed in the air intake direction. The second end 132 extends outward in the radial direction of the impeller 10 and exceeds the periphery of the first end plate 11. That is, the outer diameter D1 of the first end plate 11 is smaller than the maximum outer diameter D4 of the blade assembly at the end closest to the first end plate 11. In this way, by reducing the outer dimensions of the first end plate 11 to reduce flow losses, the second end 132 of the blade 13, which extends outward beyond the first end plate 11, can still guide the airflow, thereby increasing the effective length of the air outlet channel to a certain extent and improving the efficiency of the impeller 10. Of course, in other embodiments, the second end 132 may be flush with the periphery of the first end plate 11 in the radial direction of the impeller 10, or the periphery of the first end plate 11 may extend beyond the second end 132.

[0072] Specifically, the blade 13 has a leading edge 133 located near the air inlet 12a and a trailing edge 134 located away from the air inlet 12a. The outward projection of the second end portion 132 can be configured in a variety of ways. For example, referring to Figures 1 and 3 , in one embodiment, the trailing edge 134 of the second end portion 132 extends beyond the first end plate 11 in the air intake direction. This allows the second end portion 132 to extend beyond the boundary of the first end plate 11 not only in the radial direction of the impeller 10 but also in the air intake direction, thereby further improving the efficiency of the impeller 10.

[0073] Of course, the second end portion 132 may also be formed in other outwardly protruding forms. For example, referring to Figures 5 and 6 , in another embodiment, the trailing edge 134 of the second end portion 132 may be provided with an outwardly protruding transition fillet 135, with the transition fillet 135 connecting to the edge of the first end plate 11. This not only improves the efficiency of the impeller 10, but also utilizes the characteristics of the transition fillet 135 to ensure smooth docking of the trailing edge 134 of the blade 13 with the first end plate 11, thereby avoiding the problem of insufficient local structural strength at the trailing edge 134 of the blade 13.

[0074] In some embodiments, the blades 13 have first and second ends 131 and 132, arranged sequentially in the air intake direction. The periphery of the second end plate 12 extends outward in the radial direction of the impeller 10 and beyond the first end 131. That is, the outer diameter D2 of the second end plate 12 is greater than the maximum outer diameter D3 of the blade assembly at the end closest to the second end plate 12. This shortens the distance between the periphery of the second end plate 12 and the inner wall of the air duct 41, forming a bladeless diffuser region between the second end plate 12 and the air duct 41, thereby improving the static pressure energy and efficiency of the impeller 10. Furthermore, by shortening the distance between the periphery of the second end plate 12 and the inner wall of the air duct 41 and providing guidance through the fourth plate portion 122, the gas flowing out of the impeller 10 is prevented from bypassing the second end plate 12 and flowing back into the air inlet 12a, thereby reducing the amount of circulating gas performing useless work and improving the efficiency of the impeller 10. Of course, in other embodiments, the outer diameter of the second end plate 12 may be equal to or smaller than the outer diameter of the blade assembly at the end close to the second end plate 12 .

[0075] Without loss of generality, the performance of the mixed flow impeller is mainly reflected in the air volume and noise control. The air volume and noise level are mutually dependent. Generally, the larger the air volume, the higher the noise level, and the smaller the air volume, the lower the noise level. The air volume is proportional to the rotational speed.

[0076] Combined with the design parameters of 0.7≤D1 / D2<1, D1>D4, and D2>D3, and the gradually decreasing diameter of the circles enclosed by the blades 13 in the axial direction of the air inlet, the impeller is configured as a non-uniform impeller. As shown in Figure 11, under the same air volume and efficiency conditions, the speed required by the non-uniform impeller is significantly lower than that required by the uniform impeller. Therefore, fans using non-uniform impellers can effectively increase the load and significantly reduce the speed while ensuring efficiency and air volume. Specific speed value comparisons can be referred to the table below.

[0077]

[0078] In some embodiments, the trailing edge 134 of the blade 13 extends obliquely in the direction of air intake, away from the direction of rotation of the impeller 10. That is, the trailing edge 134 of the blade 13 extends obliquely in the direction of air intake, and in the direction of rotation of the impeller 10, the end of the trailing edge 134 near the second end plate 12 is located upstream of the end of the trailing edge 134 near the first end plate 11. This improves the flow field at the tail end of the air outlet duct, creating a phase difference in the air intake direction, thereby reducing aerodynamic noise. In one embodiment, a second reference plane is defined that passes through both the axis of the impeller 10 and the center point of the trailing edge 134 of the blade 13. The angle α between the trailing edge 134 of the blade 13 and the second reference plane is configured to be α≤45°, i.e., 0<α≤45°. Of course, in other embodiments, the trailing edge 134 of the blade 13 may extend obliquely in the direction of air intake toward the direction of rotation of the impeller 10, or the trailing edge 134 of the blade 13 may extend along the axis of the impeller 10.

[0079] It is worth mentioning that through the design of structural parameters such as the shape and size of the above-mentioned structure, the performance of the impeller of the present application is significantly improved compared with the traditional equal-diameter impeller. When used on a fan, the efficiency of the fan using the non-equal-diameter impeller of this solution is greatly improved compared with the efficiency of the fan of the traditional solution. For specific efficiency comparison, please refer to Figure 12 and the table below.

[0080]

[0081] The above description is merely an optional embodiment of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made using the contents of the present application specification and drawings under the inventive concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. An impeller, wherein: The impeller comprises: A first end plate and a second end plate, wherein the second end plate and the first end plate are sequentially spaced apart along an air inlet direction of the impeller, and the second end plate is provided with an air inlet; and A plurality of blades are distributed at intervals along the circumference of the impeller, the blades connecting the first end plate and the second end plate, the first end plate comprising a first plate portion and a second plate portion arranged around the periphery of the first plate portion, the second plate portion extending obliquely in the direction away from the axis of the impeller in the air intake direction.

2. The impeller according to claim 1, wherein: The second end plate includes a third plate portion and a fourth plate portion arranged around the periphery of the third plate portion, and the fourth plate portion extends obliquely in the direction away from the axis of the impeller in the air intake direction.

3. The impeller according to claim 2, wherein: A first reference plane is defined to be perpendicular to the axis of the impeller, an angle γ between the second plate portion and the first reference plane is configured to be 10°≤γ≤40°, and / or an angle δ between the fourth plate portion and the first reference plane is configured to be 10°≤δ≤40°.

4. The impeller according to claim 2 or 3, wherein: An outer diameter of the first end plate is smaller than an outer diameter of the second end plate.

5. The impeller according to claim 4, wherein: The ratio of the outer diameter of the first end plate to the outer diameter of the second end plate is greater than or equal to 0.7; And / or, in the radial direction of the air inlet, the dimension between the projection line of the blade on the axial section of the air inlet and the axis of the air inlet gradually decreases along the air inlet direction.

6. The impeller according to claim 4 or 5, wherein: The blade has a first end and a second end which are sequentially distributed in the air inlet direction, and the second end extends outward in the radial direction of the impeller and exceeds the periphery of the first end plate.

7. The impeller according to claim 6, wherein: The trailing edge of the second end portion extends beyond the first end plate in the air intake direction; or, the trailing edge of the second end portion is provided with an outwardly convex transition fillet, and the transition fillet is connected to the edge of the first end plate.

8. The impeller according to any one of claims 1 to 7, wherein: In the air inlet direction, the trailing edge of the blade extends obliquely away from the rotation direction of the impeller.

9. The impeller according to claim 8, wherein: A second reference plane is defined to pass through the axis of the impeller and the center point of the trailing edge of the blade at the same time, and the angle between the trailing edge of the blade and the second reference plane is less than or equal to 45°.

10. The impeller according to any one of claims 1 to 9, wherein: The blade has a first end and a second end that are sequentially distributed in the air inlet direction, and the periphery of the second end plate extends outward in the radial direction of the impeller and exceeds the first end; and / or, the outlet installation angle of the blade is less than 90°; And / or, the plate surface of the first plate portion is orthogonal to the axis of the impeller.

11. A fan, wherein: The fan comprises a motor and an impeller according to any one of claims 1 to 10, wherein a rotating shaft of the motor is arranged on a first end plate of the impeller.

12. The fan according to claim 11, wherein: The fan also includes a guide cover, which is arranged upstream of the impeller and has a cross-sectional area that gradually decreases in the air intake direction. The guide cover has a guide end and a guide end that are sequentially distributed in the air intake direction, and the guide end extends into the air inlet of the second end plate.

13. The fan according to claim 12, wherein: In the radial direction of the impeller, the gap d between the guide end and the edge of the air inlet is configured to be 4 mm ≤ d ≤ 10 mm; And / or, the depth H of the guide end extending into the air inlet is configured to be 5mm≤H≤15mm.

14. An air handling unit, wherein: The air handling unit comprises the impeller according to any one of claims 1 to 10, or comprises the fan according to any one of claims 11 to 13.

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