Fan volute with adjustable profile and fan for testing

Abstract

The present application relates to a type line adjustable fan volute and a test fan, which can improve fan performance and significantly reduce design iteration time and manufacturing cost. The type line adjustable fan volute comprises: a volute frame comprising a pair of end covers arranged at intervals, each end cover having an air inlet and a plurality of adjustment grooves arranged around the air inlet, the adjustment grooves being curved grooves extending along the radial direction of the air inlet; a volute ring wall comprising a flexible side wall movably arranged between the two end covers and a volute tongue fixedly arranged between the two end covers; and a plurality of adjustment assemblies, each adjustment assembly comprising an adjustment rod slidably inserted into the opposite adjustment grooves of the two end covers and abutting against the flexible side wall, and a fixed cover plate connected to both ends of the adjustment rod and located outside the two end covers respectively; the fixed cover plate extends outward from the adjustment rod to always cover the adjustment grooves when adjusted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of centrifugal fan, in particular to a fan volute with adjustable profile and a fan for testing. BACKGROUND

[0002] In the development and design process of range hood, the experimental test of centrifugal fan plays a crucial role, because this test not only ensures that the performance of the fan meets specific requirements, but also helps to optimize the design, improve energy efficiency and reduce noise. Finally, through accurate testing, engineers can verify and improve the design, so as to produce more efficient and user-friendly range hood.

[0003] However, in the traditional test process of centrifugal fan, the design and manufacture of volute structure face a significant challenge, specifically: whenever the test data reveals the shortcomings of the design, and a new design scheme needs to be tried, the engineer must process a brand new volute, which not only leads to a long waiting time for sample making, but also significantly increases the length of the test cycle, thereby affecting the product's time to market, and significantly increasing the development cost of the centrifugal fan. Especially in today's increasingly competitive market, such delays and cost increases can have a serious negative impact on the market position of the enterprise. SUMMARY

[0004] Therefore, it is necessary to solve the problem of long test cycle and high development cost of volute structure, and the present application provides a fan volute with adjustable profile and a fan for testing, which can improve the performance of the fan, significantly reduce the iteration time of the design and the manufacturing cost.

[0005] In an embodiment of the present application, the present application provides a fan volute with adjustable profile, comprising:

[0006] A volute frame comprising a pair of end caps arranged at intervals, each of the end caps having an air inlet and a plurality of adjustment grooves arranged at intervals around the air inlet, the adjustment grooves being curved grooves extending along the radial direction of the air inlet;

[0007] A volute ring wall comprising a flexible side wall movably arranged between the two end caps and a volute tongue fixedly arranged between the two end caps; one end of the flexible side wall is fixedly connected to the two end caps to form an air outlet with the volute tongue; the other end of the flexible side wall is wound in the volute tongue to form a winding drum; and

[0008] A plurality of adjusting assemblies, each of which comprises an adjusting rod slidably inserted into the adjusting slots on the opposite ends of the end caps and abutting against the outer wall surface of the elastic side wall, and a fixed cover plate connected to both ends of the adjusting rod and located outside the end caps respectively; the fixed cover plate extends outward from the adjusting rod to cover the adjusting slots at all times when the adjusting rod is positioned along the adjusting slots.

[0009] According to one embodiment of the present application, the fixed cover plate is a curved fixed plate matching the curved slots.

[0010] According to one embodiment of the present application, the curved slots extend away from the center of the air inlet along the circumferential direction of the air inlet.

[0011] According to one embodiment of the present application, the curved slots are convex arc-shaped slots; and the curved fixed plate is an arc-shaped plate matching the arc-shaped slots.

[0012] According to one embodiment of the present application, the radius of curvature of the curved slots satisfies the relationship:

[0013] r 2 *8b+r*(L 2 -R 2 -4b 2 -8bL)+4b 2 L≥0;

[0014] In the formula, r is the radius of curvature of the curved slots; b is the adjusting distance of the adjusting rod in the radial direction; L is the outermost limit dimension of the curved slots; and R is the radius of the air inlet.

[0015] According to one embodiment of the present application, the radius of curvature of the curved slots is greater than or equal to 60 mm.

[0016] According to one embodiment of the present application, the length of the adjusting slot on the end cap close to the volute tongue is less than the length of the adjusting slot on the end cap away from the volute tongue.

[0017] According to one embodiment of the present application, the profile-adjustable fan volute further comprises a pair of sealing pads between the two end caps and the ring wall of the volute respectively, each of which has an adjusting hole corresponding to the adjusting slot; the sealing pad comprises a flexible pad body protruding from the inner wall surface of the end cap and extending along the elastic side wall, and a flexible flange extending along the edge of the adjusting hole and protruding into the adjusting slot from the flexible pad body.

[0018] According to one embodiment of the present application, the adjusting assembly further comprises a buffer pad fixed to the adjusting rod and abutting against the elastic side wall, and a magnetic piece between the adjusting rod and the buffer pad and magnetically attracted to the elastic side wall.

[0019] According to another aspect of the present application, a test fan is further provided according to one embodiment of the present application, comprising:

[0020] A fan frame;

[0021] The profile-adjustable fan volute according to any one of the above is arranged in the fan frame; and

[0022] A impeller rotatably arranged in the profile-adjustable fan volute.

[0023] In summary, the profile-adjustable fan volute according to the present application, on one hand, takes into account the adjustable range of the volute profile and the available space of the fan frame by arranging the curved slot extending along the radial direction of the air inlet on the end cover, so as to improve the space utilization of the profile-adjustable fan volute to the fan frame while keeping the adjustment distance / range unchanged; on the other hand, the curved fixing piece matched with the curved slot always covers the adjusting slot when the profile is adjusted, thereby blocking the leakage of the airflow in the volute towards the outside of the end cover via the adjusting slot, so as to improve the air tightness of the profile-adjustable fan volute and ensure the normal test.

[0024] After test analysis, if it is found that the previous design has deficiencies and a new design scheme needs to be tried, the fixing position of the adjusting assembly on the corresponding adjusting slot only needs to be adjusted according to the new design scheme, so as to realize the profile adjustment of the volute ring wall, without the need for engineers to process a completely new volute, which helps to significantly shorten the test cycle time, reduce development costs, and avoid affecting the product launch time; especially in today's increasingly fierce market competition, the significant shortening of the test cycle and the significant reduction of the cost will have a positive impact on the market position of the enterprise. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A structural schematic view of a test fan according to one embodiment of the present application;

[0026] Figure 2 A first example of a profile-adjustable fan volute in a test fan according to the above embodiment of the present application is shown;

[0027] Figure 3 An exploded schematic view of the profile-adjustable fan volute according to the above first example of the present application is shown;

[0028] Figure 4An enlarged schematic view of the adjustment assembly in the profile-adjustable fan volute of the above first example of the present application is shown;

[0029] Figure 5 A cross-sectional schematic view of the profile-adjustable fan volute of the above first example of the present application is shown, taken from the volute ring wall;

[0030] Figure 6 An enlarged schematic view of the profile-adjustable fan volute of the above first example of the present application is shown; Figure 5 An enlarged schematic view of the profile-adjustable fan volute of the above first example of the present application is shown;

[0031] Figure 7 A cross-sectional schematic view of the profile-adjustable fan volute of the above first example of the present application is shown, taken from the end cover;

[0032] Figure 8 An enlarged schematic view of the profile-adjustable fan volute of the above first example of the present application is shown; Figure 7 An enlarged schematic view of the profile-adjustable fan volute of the above first example of the present application is shown;

[0033] Figure 9 A schematic view of the limit position of the curved fixing piece in the profile-adjustable fan volute of the above first example of the present application is shown;

[0034] Figure 10 A schematic view of the limit position of the curved fixing piece in the profile-adjustable fan volute of the above first example of the present application is shown;

[0035] Figure 11 A second example of the profile-adjustable fan volute in the fan for testing of the above example of the present application is shown;

[0036] Figure 12 An exploded schematic view of the profile-adjustable fan volute of the above second example of the present application is shown;

[0037] Figure 13 A cross-sectional schematic view of the profile-adjustable fan volute of the above second example of the present application is shown;

[0038] Figure 14 A side view schematic view of the profile-adjustable fan volute of the above second example of the present application is shown;

[0039] Figure 15 A schematic view of the slotted inner diameter in the profile-adjustable fan volute of the above second example of the present application is shown.

[0040] Main element symbol explanation: 1, fan volute with adjustable profile; 10, volute frame; 11, end cover; 111, air inlet; 112, adjusting groove; 1120, curved groove; 1121, semicircular groove; 113, convex shaft; 20, volute ring wall; 21, elastic side wall; 210, winding drum; 22, volute tongue; 23, clock spring; 30, adjusting assembly; 31, adjusting rod; 32, fixed cover plate; 320, bent fixed plate; 321, annular fixed plate; 33, buffer pad; 34, magnetic member; 40, sealing pad; 400, adjusting hole; 41, flexible pad body; 42, flexible flange; 50, position identifier; 60, angle identifier; 2, fan frame.

[0041] The above main element symbol explanation further details the present application in combination with the drawings and the specific embodiments. Specific embodiments

[0042] In order to make the above-mentioned objectives, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application are described in detail below in combination with the drawings. In the following description, a lot of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0043] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0044] In addition, the terms "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0045] In this application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0046] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on another element or there can be a mediating element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a mediating element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0047] It is considered that in the conventional centrifugal fan test process, whenever the test data reveals the shortcomings of the design, and a new design scheme needs to be tried, the engineer must process a brand new volute, which not only leads to a long waiting time for sampling, but also significantly increases the length of the test cycle, thereby affecting the product's time to market, and significantly increasing the development cost of the centrifugal fan. Therefore, the present application provides a profile-adjustable fan volute and a test fan, which can significantly reduce the iteration time of the design and the manufacturing cost.

[0048] Specifically, referring to the drawings Figures 1 to 15 An embodiment of the present application provides a test fan, which can include a fan frame 2, a profile-adjustable fan volute 1 disposed in the fan frame 2, and an impeller (not shown in the figure) rotatably disposed in the profile-adjustable fan volute 1 for performing optimization test of the centrifugal fan. It can be understood that the impeller of the present application can include, but is not limited to, a rotating shaft, a motor drivingly connected to the rotating shaft, and a plurality of blades arranged at intervals along the circumference of the rotating shaft, which will not be described here.

[0049] More specifically, as Figures 2 to 5As shown, the profile-adjustable fan volute 1 can include a volute frame 10, a volute ring wall 20, and a plurality of adjusting assemblies 30. The volute frame 10 includes a pair of end covers 11 arranged at intervals, each of which has an air inlet 111 and a plurality of adjusting grooves 112 arranged around the air inlet 111. The volute ring wall 20 includes a flexible side wall 21 movably arranged between the two end covers 11 and a volute tongue 22 fixed between the two end covers 11; one end of the flexible side wall 21 is fixedly connected to the two end covers 11 to enclose an air outlet with the volute tongue 22; the other end of the flexible side wall 21 is rolled into the volute tongue 22 to form a winding drum 210. Each adjusting assembly 30 includes an adjusting rod 31 slidably inserted into the opposite adjusting grooves 112 of the two end covers 11 and abutting against the outer wall surface of the flexible side wall 21, and a fixed cover plate 32 connected to both ends of the adjusting rod 31 and located outside the two end covers 11 respectively; the fixed cover plate 32 extends outward from the adjusting rod 31 to always cover the adjusting grooves 112 when the adjusting rod 31 is adjusted along the adjusting grooves 112 to adjust the profile of the volute ring wall 20. It can be understood that the flexible side wall 21 mentioned in the present application can be implemented as a metal coil or a plastic coil, but is not limited thereto, and can be elastically deformed in the radial direction of the air inlet 111, which will not be described herein.

[0050] It is worth noting that during the test by the test fan, each adjusting rod 31 can be fixed at the required position on the corresponding adjusting groove 112 according to the profile design needs; at this time, the impeller is rotated to increase the wind pressure in the volute, so that the flexible side wall 21 better abuts against all adjusting rods 31 under the action of wind pressure, to ensure that the actual profile of the volute ring wall 20 is consistent with the designed profile; after test analysis, if it is found that the previous design needs to be tried new design scheme, only the fixed position of the adjusting rod 31 on the corresponding adjusting groove 112 needs to be adjusted according to the new design scheme, the profile adjustment of the volute ring wall 20 can be realized, without the need for engineers to process a completely new volute, which helps to significantly shorten the length of the test cycle, reduce development costs, and avoid affecting the product's time to market; especially in today's increasingly competitive market, the significant reduction of the test cycle and the cost will have a positive impact on the market position of the enterprise.

[0051] In addition, since the other end of the elastic side wall 21 is wound in the volute tongue 22, the circumference of the volute ring wall 20 can be adjusted to meet the requirements of different profile design schemes. In other words, when the profile circumference in the profile design scheme becomes shorter, the elastic side wall 21 can be partially wound in the volute tongue 22 to shorten the circumference of the volute ring wall 20; when the profile circumference in the profile design scheme becomes longer, the elastic side wall 21 can be partially pulled out of the volute tongue 22 to lengthen the circumference of the volute ring wall 20, greatly increasing the flexibility of the profile design scheme adjustment.

[0052] According to the above embodiments of the present application, as shown in Figure 3 and Figure 5 The volute ring wall 20 can further include a clock spring 23 arranged between the winding drum 210 and the volute tongue 22, for applying a winding torque to the winding drum 210, so that the other end of the elastic side wall 21 can be automatically wound in the volute tongue 22 under the action of the clock spring 23, so as to ensure that the elastic side wall 21 is always in an automatically tensioned state. In this way, when adjusting the fixed position of the adjusting rod 31 to adjust the ring wall profile, if the ring wall circumference increases, the winding drum 210 will be partially relaxed to protrude out of the volute tongue 22 and abut against the adjusting rod 31 under the action of its own elasticity and the wind pressure in the volute; if the ring wall circumference decreases, the excess part of the elastic side wall 21 will be automatically wound under the action of the clock spring 23 to retract into the volute tongue 22, and the volute ring wall 20 can still abut against the adjusting rod 31 under the action of its own elasticity and the wind pressure in the volute, thereby realizing controllable adjustment of the ring wall profile.

[0053] It is worth noting that although the fixed cover plate 32 always covers the adjusting slot 112 when the adjusting rod 31 is adjusted along the adjusting slot 112, to block the leakage of the airflow in the volute towards the outside of the end cover 11 through the adjusting slot 112, improving the accuracy of the test results; but if the adjusting slot 112 extends straight along the radial direction of the air inlet 111 to form a strip-shaped sliding groove, and the outer edge of the strip-shaped sliding groove is spaced apart from the edge of the end cover 11 by a distance t, then limited by the width M of the fan frame 2, the actual profile of the profile-adjustable fan volute 1 is limited within the area of M-2t.

[0054] Furthermore, since the fixed cover plate 32 needs to cover the adjusting groove 112 under both inner and outer extreme exposure conditions, and the edge of the end cover 11 is essentially determined by the extreme outer edge of the fixed cover plate 32, the size of the aforementioned spacing t mainly depends on the length a of the strip groove, i.e., spacing t ≥ ad, where d is the diameter of the adjusting rod 31. Obviously, the larger the length a of the adjusting groove 112, the greater the inward adjustable range of the profile of the adjustable fan casing 1, but the smaller the actual usable space of the adjustable fan casing 1 within the fan frame 2. Therefore, in order to balance the adjustable range and usable space, such as... Figure 3 and Figure 4 As shown, the adjustment groove 112 of this application is implemented as a curved groove 1120 extending radially along the air inlet 111; the fixed cover plate 32 is implemented as a curved fixing piece 320 matching the curved groove 1120, so that while ensuring that the adjustment distance / range remains unchanged, the outermost adjustable profile of the profile adjustable fan volute 1 is shortened relative to the edge distance of the end cover 11, thereby improving the space utilization rate of the profile adjustable fan volute 1 on the fan frame 2.

[0055] Exemplarily, in the first example of this application, such as Figures 3 to 10 As shown, the curved groove 1120 can extend gradually away from the center of the air inlet 111 along the circumferential direction of the air inlet 111, so that the distance between the adjusting rod 31 and the center of the air inlet 111 gradually changes when sliding along the curved groove 1120, which facilitates the adjustment of the volute profile. It is worth noting that in this example of the present application, the radius of curvature of the curved groove 1120 can remain constant to form an arc-shaped groove with a central angle of less than 90°; of course, in other examples of the present application, the radius of curvature of the curved groove 1120 can also change, which will not be elaborated here.

[0056] Optionally, the curved groove 1120 is implemented as an outwardly convex arcuate groove to shorten the dimension of the curved fixing piece 320 protruding outward from the volute annular wall 20, which is beneficial to shortening the distance v between the outer side of the curved fixing piece 320 and the edge of the end cap 11. It is understood that the central angle of the arcuate groove mentioned in this application is generally less than 90°.

[0057] Optionally, such as Figure 4 , Figure 9 as well as Figure 10 As shown, the curved fixing piece 320 is implemented as an arc-shaped piece that matches the arc-shaped groove, so as to minimize the material used of the curved fixing piece 320 while always covering the arc-shaped groove, which helps to further improve the space utilization of the fan frame 2.

[0058] It is worth noting that although the curved groove 1120 can shorten the protruding size of the curved fixing piece 320 to the outside of the volute ring wall 20, it will increase the occupying size of the curved fixing piece 320 to the inside of the volute ring wall 20, causing the curved fixing piece 320 to partially block the air inlet 111, seriously affecting the test of the fan. Therefore, the present application hopes to set a reasonable curved groove 1120 to shorten the distance v between the outside of the curved fixing piece 320 and the edge of the end cover 11, while avoiding the blocking of the air inlet 111 when the curved fixing piece 320 adjusts inward.

[0059] Through analysis, it is found that in the case of the same length of the adjusting groove 112, the radial width of the end cover 11 is narrower near the volute tongue 22, and the radial width of the end cover 11 is wider away from the volute tongue 22; therefore, the curved fixing piece 320 near the volute tongue 22 is more likely to block the air inlet 111, and the curved fixing piece 320 away from the volute tongue 22 is less likely to block the air inlet 111.

[0060] At the same time, since the profile-adjustable fan volute 1 usually has a smaller adjusting range of the ring wall profile near the volute tongue 22 and a larger adjusting range of the ring wall profile away from the volute tongue 22 during the actual adjustment of the ring wall profile, the profile-adjustable fan volute 1 of the present application can be provided with different adjusting lengths b at different parts of the end cover 11, that is, the profile-adjustable fan volute 1 can be provided with adjusting grooves 112 of different lengths at different parts of the end cover 11. It can be understood that the adjusting length b mentioned in the present application refers to the radial distance of the adjusting rod 31 sliding along the adjusting groove 112.

[0061] Specifically, as shown in Figure 9 and Figure 10 , the length of the adjusting groove 112 near the volute tongue 22 on the end cover 11 is smaller than the length of the adjusting groove 112 away from the volute tongue 22 on the end cover 11; in other words, the end cover 11 is provided with a shorter adjusting groove 112 near the volute tongue 22 along the extension direction of the elastic side wall 21, and the end cover 11 is provided with a longer adjusting groove 112 away from the volute tongue 22 along the extension direction of the elastic side wall 21, so that the adjusting length near the volute tongue 22 on the end cover 11 is smaller than the adjusting length away from the volute tongue 22 on the end cover 11, so as to meet the adjusting demand of the ring wall profile while reducing the risk of the curved fixing piece 320 blocking the air inlet 111 as much as possible.

[0062] In addition, it is found through analysis that the greater the curvature radius r of the curved groove 1120, the less likely the curved fixed piece 320 is to block the air inlet 111; but the greater the curvature radius r of the curved groove 1120, the longer the length of the curved groove 1120 needs to be in order to ensure sufficient radial adjustment length, resulting in a larger circumferential offset of the adjustment rod 31. Therefore, the specific curvature radius r of the adjustment groove 112 needs to be determined based on the size of the air inlet 111, the outermost limit size of the adjustment groove 112, and the adjustment size required for the adjustment of the ring wall profile, so that the curvature radius r is as small as possible.

[0063] More specifically, as shown in the figure, a coordinate system X-Y is constructed with the center O of the curved groove 1120 as the origin, and the limit position coordinates (Xg, Yg) of the curved fixed piece 320 substantially satisfy the following relationships: Xg = r*cos2α; Yg = r*sin2α; where α is the central angle of the curved groove 1120. Figure 9

[0064] It is worth noting that the central angle α of the curved groove 1120 mentioned in the present application should satisfy the following relationship:

[0065]

[0066] The following relationship (1) is obtained:

[0067]

[0068] In the formula, r is the curvature radius of the curved groove 1120; b is the adjustment distance of the adjustment rod 31 in the radial direction. It can be understood that the adjustment distance b mentioned in the present application refers to the adjustment size required for the adjustment of the ring wall profile, which is set based on the test requirements of the volute, and depends on the slotting position and the size of the volute, etc., and is usually between 0.001m and 0.2m, which is considered known in the present application.

[0069] As shown in the figure, the critical position coordinates (Xa, Ya) of the curved fixed piece 320 substantially satisfy the following relationships without blocking the air inlet 111: Xa = r*cos(π-β); Yg = r*sin(π-β); where β is the limit central angle of the curved groove 1120. Obviously, in order to achieve that the curved fixed piece 320 does not block the air inlet 111, the central angle α of the curved groove 1120 should satisfy the relationship: 2α≤π-β; so as to ensure that the limit position coordinates (Xg, Yg) of the curved fixed piece 320 do not exceed the critical position coordinates (Xa, Ya) of the curved fixed piece 320. Figure 10

[0070] ​​It is worth noting that the β mentioned in the present application refers to the included angle between the line connecting the center O of the curved groove 1120 and the center C of the air inlet 111 and the critical position of the curved fixing piece 320. It can be understood that the critical position mentioned in the present application refers to the intersection between the profile of the curved groove 1120 and the circumference of the air inlet 111, and is adjacent to the proximal end of the curved groove 1120.

[0071] Then, the following relationship (2) is easily obtained from the cosine theorem:

[0072]

[0073] In the formula, r is the radius of curvature of the curved groove 1120; L is the outermost limit size of the curved groove 1120; and R is the radius of the air inlet 111. It can be understood that the outermost limit size L mentioned in the present application refers to the distance between the outer end of the curved groove 1120 and the center of the air inlet 111, which is set based on the test requirements of the volute, depends on the slotting position and the size of the volute, etc., and is usually between 0.1 m and 0.5 m, which is considered known by the present application; in addition, the radius R mentioned in the present application is set based on the test requirements, and is usually between 0.05 m and 0.2 m, which is considered known by the present application.

[0074] Thus, since π-β is within the interval (0, π), i.e. π-β < π; therefore, based on the characteristic that the cosine function is monotonically decreasing within the interval (0, π), it can be obtained from 2α ≤ π-β that cos2α ≤ cos(π-β) = -cosβ;

[0075] Further, combining the above formula (1) and formula (2) can obtain:

[0076]

[0077] Finally, after simplification, the relationship (3) satisfied by the radius of curvature r of the curved groove 1120 can be obtained, as follows:

[0078] r 2 *8b+r*(L 2 -R 2 -4b 2 -8bL)+4b 2 L≥0 (3);

[0079] In the formula, r is the radius of curvature of the curved groove 1120; b is the adjustment distance of the adjustment rod 31 in the radial direction; L is the outermost limit size of the curved groove 1120; and R is the radius of the air inlet 111.

[0080] For example, if the adjustment distance b of the adjustment rod 31 in the profile-adjustable fan volute 1 in the radial direction is 10 mm; the outermost limit size L of the curved slot 1120 is 120 mm, and the radius R of the air inlet 111 is 100 mm; then the above relationship (3) can be obtained: 80*r 2 -5600r+48000≥0;

[0081] After sorting, we get: r 2 -70r+600≥0;

[0082] Finally, after solving, we get: r≥60 mm. In other words, the curvature radius of the curved slot 1120 in the profile-adjustable fan volute 1 of the present application is preferably 60 mm, so as to avoid the blocking of the air inlet 111 by the curved fixed sheet 320 while ensuring that the circumferential offset of the adjustment rod 31 is as small as possible.

[0083] It is worth noting that although the fixed cover plate 32 always covers the adjustment slot 112 to reduce gas leakage to some extent, since the other end of the elastic side wall 21 needs to be rolled in the volute tongue 22, in order to ensure the flexibility of the overall assembly of the elastic side wall 21 adjustment position, the actual width of the elastic side wall 21 usually needs to be less than the distance between the two end covers 11, which will cause the leakage of the volute airflow from the gap between the elastic side wall 21 and the end cover 11. In order to solve this problem, as shown in Figures 2 to 8 , the profile-adjustable fan volute 1 of the present application can also include a pair of sealing pads 40 respectively located between the two end covers 11 and the volute ring wall 20; each sealing pad 40 has an adjustment hole 400 corresponding to the adjustment slot 112, so as to fill the gap between the end cover 11 and the volute ring wall 20 while ensuring that the adjustment rod 31 is inserted into the adjustment slot 112 through the adjustment hole 400 to slide along the adjustment slot 112, and block the leakage of volute airflow from the gap between the volute ring wall 20 and the end cover 11.

[0084] Alternatively, as shown in Figure 3 , Figure 5 and Figure 6 , each sealing pad 40 includes a flexible pad body 41 providing the adjustment hole 400, which is convex on the inner wall surface of the end cover 11 and extends along the elastic side wall 21 to fill the gap between the end cover 11 and the elastic side wall 21, so as to reduce airflow leakage while not affecting the movement of the elastic side wall 21, meeting the needs of volute profile adjustment.

[0085] Alternatively, as shown in Figure 3 , Figure 7 and Figure 8As shown, the sealing gasket 40 further comprises a flexible flange 42 extending along the edge of the adjusting hole 400 and protruding from the flexible pad body 41 into the adjusting groove 112, so as to firmly fix the flexible pad body 41 of the sealing gasket 40 to the inner wall surface of the end cover 11 through the flexible flange 42, preventing the flexible pad body 41 from being deviated with the movement of the elastic side wall 21. At the same time, the flexible flange 42 can also fill the gap between the adjusting rod 31 and the side wall of the adjusting groove 112, blocking the leakage of the airflow in the volute around the adjusting groove 112 bypassing the adjusting rod 31 towards the inner side of the end cover 11, i.e. avoiding the occurrence of around-column leakage, further improving the air tightness of the contour-adjustable fan volute 1 and ensuring the normal test.

[0086] Optionally, the diameter of the adjusting rod 31 is greater than the width of the adjusting hole 400 and smaller than the width of the adjusting groove 112, so as to press the flexible flange 42 between the adjusting rod 31 and the side wall of the adjusting groove 112, not only being able to better fill the gap between the adjusting rod 31 and the side wall of the adjusting groove 112 through the flexible flange 42, but also being able to adjustably fix the adjusting rod 31 in the adjusting groove 112 to a certain extent through the elastic deformation of the flexible flange 42.

[0087] Optionally, the adjusting rod 31 is threadedly connected with the fixed cover plate 32. In this way, when it is necessary to adjust the volute contour, only one fixed cover plate 32 needs to be rotated relative to the adjusting rod 31 to be loosened, and then when the adjusting rod 31 is slid along the adjusting groove 112 to the desired position, the fixed cover plate 32 can be reversely rotated to be tightened, so as to detachably position and fix the adjusting rod 31.

[0088] It is worth noting that, since the surface of the adjusting rod 31 is generally an outward convex curved surface and the surface of the elastic side wall 21 is an outward convex curved surface, if the elastic side wall 21 directly contacts the adjusting rod 31, the contact mode is implemented as linear contact, which may cause stress concentration and easily cause the part of the elastic side wall 21 contacting the adjusting rod 31 to be deformed inwardly, resulting in the decrease of the smoothness of the volute ring wall contour and further adversely affecting the accuracy of the test result. In order to solve this problem, as shown in Figure 4 and Figure 6 the adjusting assembly 30 of the present application can further comprise a buffer pad 33 fixed to the adjusting rod 31 and abutting against the elastic side wall 21. In this way, the flexible deformation of the buffer pad 33 can increase the contact area of the adjusting assembly 30 and the elastic side wall 21, facilitating the reduction of stress concentration and helping to improve the smoothness of the ring wall contour. It can be understood that the buffer pad 33 mentioned in the present application can be but is not limited to made of flexible materials such as silica gel or rubber.

[0089] In addition, when the ring wall profile of the profile-adjustable fan volute 1 is switched from the small-curvature scheme to the large-curvature scheme, the elastic side wall 21 tends to keep the original curvature; at this time, in the working condition of the lower power gear, the wind pressure in the volute is relatively small and can be insufficient to make the elastic side wall 21 abut against the adjusting assembly 30, resulting in that the ring wall profile adjustment is not in place, affecting the reliability of the test results. In order to solve this problem, as shown in Figure 4 and Figure 6 The adjusting assembly 30 of the present application can further include a magnetic piece 34 between the adjusting rod 31 and the buffer pad 33 and magnetically attracted to the elastic side wall 21, so as to magnetically pull the elastic side wall 21 through the magnetic piece 34, so that the elastic side wall 21 can still abut against the buffer pad 33 of the adjusting assembly 30 in the working condition of the low power gear (i.e. the wind pressure in the volute is relatively small), ensuring that the ring wall profile adjustment is in place. It can be understood that although the elastic side wall 21 can always abut against the adjusting assembly 30 under the magnetic pull of the magnetic piece 34, the elastic side wall 21 can still slide relative to the adjusting assembly 30 and will not hinder the change of the ring wall circumference during the profile adjustment; at the same time, the magnetic piece 34 located outside the elastic side wall 21 will not adversely affect the flow field in the volute, which is beneficial to ensure the reliability of the test results.

[0090] Exemplarily, the elastic side wall 21 can be implemented as a magnetic piece, i.e. the elastic side wall 21 can be but not limited to made of a magnetic material such as iron or alloy; the magnetic piece 34 can be correspondingly implemented as a magnet, so that the magnetic piece 34 and the elastic side wall 21 generate a magnetic attraction force to magnetically pull the elastic side wall 21.

[0091] Optionally, as shown in Figure 4 and Figure 6 The buffer pad 33 and the magnetic piece 34 both have a sheet structure to be attached to the mounting surface of the adjusting rod 31, so that when the adjusting rod 31 slides along the curved groove 1120, the elastic side wall 21 can always abut against the buffer pad 33 under the magnetic pull of the magnetic piece 34.

[0092] Optionally, the lengths of the buffer pad 33 and the magnetic piece 34 are equal to the width of the elastic side wall 21.

[0093] It is worth mentioning that, Figures 11 to 15 a second example of the profile-adjustable fan volute 1 in the test fan of the above-mentioned embodiments of the present application is shown. Compared with the above-mentioned first example according to the present application, the difference between the second example of the profile-adjustable fan volute 1 according to the present application is that, as shown in Figure 11 and Figure 13As shown, the adjusting groove 112 can also be implemented as a semicircular groove 1121; correspondingly, the fixed cover plate 32 is implemented as an annular fixed sheet 321 arranged concentrically with the semicircular groove 1121. In this way, when the adjusting rod 31 moves along the semicircular groove 1121 to adjust the torus wall profile, the annular fixed sheet 321 can always cover the semicircular groove 1121 to achieve a sealing effect; at the same time, since the inward and outward movement range of the adjusting rod 31 and the shielding range of the annular fixed sheet 321 are visually visible, the curvature radius of the semicircular groove 1121 can be determined without complicated calculation. In addition, compared with the first example described above, in the case of equal radial adjustment range of the adjusting rod 31, the circumferential offset of the adjusting rod 31 in the second example of the present application is greatly reduced.

[0094] Optionally, as shown in Figure 12 and Figure 14 , the adjusting rod 31 is fixedly connected to the annular fixed sheet 321, and the adjusting rod 31 is arranged eccentrically relative to the annular fixed sheet 321. In this way, when the adjusting rod 31 slides along the semicircular groove 1121, the annular fixed sheet 321 will rotate synchronously to always cover the semicircular groove 1121.

[0095] It is worth noting that in order to make the annular fixed sheet 321 always cover the semicircular groove 1121, the annular fixed sheet 321 needs to make a circular motion around the center of the semicircular groove 1121, so that the adjusting rod 31 fixedly connected to the annular fixed sheet 321 will also rotate synchronously; therefore, as shown in Figure 13 , in order to ensure that the buffer pad 33 on the adjusting rod 31 can always face the elastic side wall 21, the buffer pad 33 of the present application can have an annular structure to be implemented as an annular pad sleeved outside the adjusting rod 31.

[0096] Optionally, as shown in Figure 13 , the magnetic member 34 is implemented as an annular magnet sleeved outside the adjusting rod 31, and the annular pad is located outside the annular magnet, so as to better magnetically attract the elastic side wall 21 to always abut against the annular pad.

[0097] In addition, in order to facilitate the adjustment of the annular fixed sheet 321 to make a circular motion around the center of the semicircular groove 1121, as shown in Figure 11 and Figure 14 , the end cover 11 of the present application further has a convex shaft 113 arranged coaxially with the semicircular groove 1121, and the annular fixed sheet 321 is rotatably sleeved on the convex shaft 113, facilitating the centering rotation with the convex shaft 113 as the rotation axis, so as to ensure that the annular fixed sheet 321 can always cover the semicircular groove 1121.

[0098] It is worth noting that since the annular fixing piece 321 will shield the adjusting rod 31, and the adjusting rod 31 is arranged eccentrically relative to the annular fixing piece 321, the position of the adjusting rod 31 will be difficult to determine when adjusting the ring wall profile. In order to solve this problem, as shown in Figure 14 the profile-adjustable fan volute 1 of the present application can further include a position mark 50 arranged on the annular fixing piece 321 and corresponding to the adjusting rod 31, for indicating the position of the adjusting rod 31 relative to the annular fixing piece 321, so as to intuitively identify the position of the adjusting rod 31 and facilitate the adjustment of the ring wall profile. It can be understood that the position mark 50 mentioned in the present application can be but not limited to a mark groove opened on the outer side of the annular fixing piece 321.

[0099] In addition, in order to further improve the adjustment accuracy of the profile, as shown in Figure 14 the profile-adjustable fan volute 1 of the present application can further include an angle mark 60 arranged on the convex shaft 113 and corresponding to the semicircular arc groove 1121, so as to clearly display the sliding angle of the adjusting rod 31 in the semicircular arc groove 1121 by the cooperation of the position mark 50 on the annular fixing piece 321 and the angle mark 60 on the convex shaft 113, thereby completing the adjustment of the volute ring wall profile with high accuracy. It can be understood that the angle mark 60 mentioned in the present application can be but not limited to an angle scale opened on the end face of the convex shaft 113, and the scale compensation can be specified according to the test requirements, which can usually be between 10° and 60°.

[0100] In particular, the angle mark 60 mentioned in the present application can not only be used as an identifier during fan testing, but also can be used to obtain the coordinates of the actual volute profile control points after determining the volute with good air performance, for drawing design. It can be understood that since the convex shaft 113 on the end cover 11 is coaxially arranged with the semicircular arc groove 1121, the coordinates of the center of the convex shaft 113 relative to the center of the air inlet 111 are known, so as to know the coordinates of the actual control points, only the relative coordinates between the control points and the center of the convex shaft 113 need to be calculated.

[0101] Exemplarily, as shown in Figure 15 the center O of the convex shaft 113 as the origin, the profile control point coordinates (Xk, Yk) of the volute ring wall 20 satisfy the following relationship:

[0102]

[0103]

[0104] μ = π - α - β - γ;

[0105]

[0106] In the formula, R is the slot inner diameter of the semicircular slot 1121; r is the radius of the adjusting assembly 30; a is the included angle between the center line of the convex shaft 113 and the Y axis and the air inlet; and β is the included angle between the outermost limit scale of the position mark and the angle mark. It can be understood that the slot inner diameter mentioned in the present application depends on the design adjustment range of the semicircular slot 1121, and is usually between 5 mm and 100 mm, which is considered known in the present application; the radius r mentioned in the present application refers to the sum of the radii of each part in the adjusting assembly 30, i.e. r = a + b + c, where a is the radius of the adjusting rod 31; b is the wall thickness of the magnetic part 34; and c is the wall thickness of the buffer pad 33; and the radius r is usually between 3 mm and 20 mm, which is considered known in the present application; the included angle a mentioned in the present application depends on the position of the convex shaft 113; and the included angle β mentioned in the present application is an adjustable parameter of the test volute, and the control point coordinates can be calculated based on the read angle parameter.

[0107] In summary, the coordinates of the control point relative to the center of the convex shaft 113 can be calculated by the above relationship, and the coordinates of the control point relative to the center of the air inlet 111 can be easily obtained; thus, the angle β directly read on the test volute can be converted into the coordinates required for drawing, and the drawing of the volute drawing can be realized.

[0108] The technical features of the above embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present application.

[0109] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, some modifications and improvements can be made, which are all within the protection scope of the present application.

Claims

1. A fan casing with adjustable profile, characterized in that, include: A volute frame includes a pair of end caps spaced apart, each end cap having an air inlet and a plurality of adjustment slots spaced apart around the air inlet, the adjustment slots being curved grooves extending radially along the air inlet. The volute annular wall includes an elastic sidewall movably disposed between the two end caps and a volute tongue fixedly disposed between the two end caps; one end of the elastic sidewall is fixedly connected to the two end caps to form an air outlet with the volute tongue; the other end of the elastic sidewall is rolled up inside the volute tongue to form a roll. as well as Multiple adjustment components, each of the adjustment components including an adjustment rod slidably inserted into the opposing adjustment slots on the two end caps and abutting against the outer wall surface of the elastic sidewall, and a fixed cover plate connected to both ends of the adjustment rod and located on the outside of the two end caps respectively; the fixed cover plate extends outward from the adjustment rod to always cover the adjustment slot when the adjustment rod is adjusted along the adjustment slot.

2. The adjustable profile fan casing according to claim 1, characterized in that, The fixed cover plate is a curved fixing piece that matches the curved groove.

3. The adjustable profile fan casing according to claim 2, characterized in that, The curved groove extends gradually away from the center of the air inlet along the circumferential direction of the air inlet.

4. The adjustable profile fan casing according to claim 3, characterized in that, The curved groove is an outwardly convex arc-shaped groove; the bending fixing piece is an arc-shaped piece that matches the arc-shaped groove.

5. The adjustable profile fan casing according to any one of claims 1 to 4, characterized in that, The radius of curvature of the curved groove satisfies the following relationship: r 2 *8b+r*(L 2 -R 2 -4b 2 -8bL)+4b 2 L≥0; In the formula: r is the radius of curvature of the curved groove; b is the adjustment distance of the adjusting rod in the radial direction; L is the outermost limit dimension of the curved groove; and R is the radius of the air inlet.

6. The adjustable profile fan casing according to any one of claims 1 to 4, characterized in that, The radius of curvature of the curved groove is greater than or equal to 60 mm.

7. The adjustable profile fan casing according to any one of claims 1 to 4, characterized in that, The length of the adjustment groove on the end cap near the volute tongue is less than the length of the adjustment groove on the end cap away from the volute tongue.

8. The adjustable profile fan casing according to any one of claims 1 to 4, characterized in that, It also includes a pair of sealing gaskets located between the two end caps and the volute annular wall, each sealing gasket having an adjustment hole corresponding to the adjustment groove; the sealing gasket includes a flexible pad body protruding from the inner wall surface of the end cap and extending along the elastic sidewall, and a flexible flange extending along the edge of the adjustment hole and extending from the flexible pad body into the adjustment groove.

9. The adjustable profile fan casing according to any one of claims 1 to 4, characterized in that, The adjustment assembly further includes a buffer pad fixed to the adjustment rod and in contact with the elastic sidewall, and a magnetic element located between the adjustment rod and the buffer pad and magnetically attracting the elastic sidewall.

10. A test fan, characterized in that, include: Wind turbine frame; The adjustable profile fan casing as described in any one of claims 1 to 9, wherein the adjustable profile fan casing is disposed within the fan frame; as well as An impeller is rotatably mounted on the volute of the profile-adjustable fan.

Images