Volute assembly of centrifugal fan, centrifugal fan and range hood

Abstract

The utility model discloses a volute assembly of centrifugal fan, centrifugal fan and range hood, the volute assembly of centrifugal fan comprises two cover plates that are arranged at interval, an annular wall is arranged between the two cover plates, the annular wall comprises a volute tongue; the annular wall further comprises a molded line adjusting assembly, the molded line adjusting assembly comprises a rotating shaft and a deformable annular wall body, the rotating shaft is parallel to the axis of the centrifugal fan and is adjacent to the volute tongue in the circumferential direction, the two ends of the rotating shaft are rotationally connected with the cover plates at the corresponding positions respectively, and the annular wall body is partially wound around the rotating shaft. The end part of the ring wall main body is fixedly connected with the rotating shaft; the volute assembly further comprises a movement mechanism used for driving the rotating shaft to rotate and enabling the annular wall body to move inwards in the radial direction so as to shorten the molded line of the annular wall. The ring wall body maintains a trend that makes the ring wall profile longest.

Description

Technical Field

[0001] This utility model relates to power devices, and more particularly to a volute assembly of a centrifugal fan, a centrifugal fan using the volute assembly, and a range hood using the centrifugal fan. Background Technology

[0002] According to GB / T 17713-2022 "Range Hoods and Other Cooking Smoke Extraction Devices", the main noise evaluation indicators for range hoods include semi-anechoic chamber noise and operating noise. These parameters, as nominal indicators, are important bases for users to intuitively compare product performance, and noise also directly affects the user experience. Therefore, reducing the semi-anechoic chamber noise and operating noise of range hoods is crucial.

[0003] The fan system is the main structure affecting the noise of a range hood. Among the many methods to reduce the noise of a range hood, designing a reasonable volute profile is a common approach. Optimizing the volute profile can improve airflow and thus reduce eddy noise, as illustrated by the improved volute profiles disclosed in Chinese patents with application numbers 201110118687.5 and 201710798758.8.

[0004] However, the current volute profile design with the lowest noise level under semi-anechoic chamber conditions is not consistent with the profile design with the lowest noise level under full-duration noise conditions. That is, some volute profiles have low noise under semi-anechoic chamber conditions, but high noise under full-duration noise conditions, and vice versa.

[0005] Therefore, the volute profiles currently used in products typically require a trade-off between the semi-anechoic chamber noise and operating noise levels, and cannot simultaneously meet both requirements. Further improvements are needed. Utility Model Content

[0006] The first technical problem to be solved by this utility model is to address the shortcomings of the existing technology by providing a centrifugal fan volute assembly that can be adjusted in real time to meet the requirements of lower semi-anechoic chamber noise and operating noise.

[0007] The second technical problem to be solved by this utility model is to provide a centrifugal fan that uses the above-mentioned volute assembly.

[0008] The third technical problem to be solved by this utility model is to provide a range hood that uses the above-mentioned centrifugal fan.

[0009] The technical solution adopted by this utility model to solve the first technical problem mentioned above is as follows: a centrifugal fan volute assembly, comprising two cover plates arranged at intervals, and an annular wall provided between the two cover plates, wherein the annular wall includes a volute tongue; characterized in that:

[0010] The ring wall also includes a profile adjustment assembly, which includes a rotating shaft and a deformable ring wall body. The rotating shaft is parallel to the axis of the centrifugal fan and is adjacent to the volute tongue in the circumferential direction. Both ends of the rotating shaft are rotatably connected to the cover plates at corresponding positions. A portion of the ring wall body is wound around the rotating shaft, and the end of the ring wall body is connected and fixed to the rotating shaft.

[0011] The volute assembly also includes a motion mechanism for driving the rotating shaft to rotate, which enables the ring wall body to move radially inward to shorten the ring wall profile.

[0012] The main body of the ring wall maintains the tendency to maximize the ring wall profile.

[0013] By setting a deformable annular wall body, which is fixed to the rotating shaft and partially wound around it, the annular wall body can be moved inward by the rotation of the rotating shaft under the action of the motion mechanism, thereby shortening the annular wall profile until the base circle radius of the spiral line of the profile reaches its minimum. At this point, the annular wall profile reaches its shortest length, while still tending to maximize the profile (the base circle radius of the spiral line of the profile reaches its maximum length). This allows the profile to be changed according to actual working conditions, resulting in lower noise and operating noise in the semi-anechoic chamber. Only one motion mechanism is needed to drive the rotating shaft, making the electrical control simple, requiring fewer components, and reducing costs. By winding the annular wall body partially around the rotating shaft, the circumference can be changed accordingly when the profile changes, avoiding changes in the position of the starting end, which could lead to increased gap and pressure loss at the adjacent volute tongue, or misalignment between the volute outlet and the cover plate, thus ensuring the normal operation of the centrifugal fan.

[0014] Furthermore, to facilitate maintaining the longest possible annular wall profile, the profile adjustment assembly also includes an annular wall airbag. The annular wall airbag is adhered to the outer side of the annular wall body, ensuring the annular wall body maintains the longest possible annular wall profile. Because the annular wall airbag is tightly attached to the annular wall body, the force applied to the annular wall body is more uniform, which helps improve the smoothness of the annular wall. Moreover, the annular wall airbag is lightweight, enabling a lightweight design for the volute assembly.

[0015] Preferably, to facilitate the rotation of the drive shaft, the motion mechanism includes a drive mechanism and a transmission mechanism for transmitting the output of the drive mechanism to the drive shaft. The drive mechanism is a motor, and the transmission mechanism is a gear set.

[0016] Furthermore, to facilitate the fixing of the relative positions of the two cover plates, the volute assembly also includes a fastening plate disposed on the outer side of the ring wall body. The fastening plate is parallel to the extension direction of the rotating shaft, and the two ends of the fastening plate are bent and welded to the cover plates at the corresponding positions.

[0017] Furthermore, to facilitate the fixing of the fastening plate and the cover plate, the two ends of the fastening plate are bent and welded to the cover plate at the corresponding positions.

[0018] Furthermore, to facilitate defining the relative positions of the annular wall body and the cover plate in the height direction of the volute and to avoid pressure leakage due to unevenness, a flange is formed at the end of the annular wall body away from the fixed axis. The flange is formed on opposite sides of the annular wall body. A limiting groove is formed on the side of each cover plate facing the inside of the volute assembly. The limiting groove extends along the width direction of the volute assembly. The flange is engaged in the limiting groove and can move linearly along the limiting groove.

[0019] To facilitate control of the inner steady-state position of the ring wall profile, each cover plate also has a limiting protrusion on the side facing the inside of the volute assembly, and the limiting protrusion is located on the radial inner side of the ring wall body.

[0020] To facilitate control of the steady-state position of the outer side of the ring wall profile, a limiting flange is also formed on the outer edge of each cover plate. Each limiting flange is formed by bending the edge of the cover plate toward another cover plate.

[0021] The technical solution adopted by this utility model to solve the second technical problem mentioned above is: a centrifugal fan, characterized in that: it uses the volute assembly as described above.

[0022] The technical solution adopted by this utility model to solve the third technical problem mentioned above is: a range hood, characterized in that: it uses a centrifugal fan as described above.

[0023] Compared with the prior art, the advantages of this utility model are as follows: By setting a deformable annular wall body, which is fixed to the rotating shaft and partially wrapped around the rotating shaft, the annular wall body can be moved inward by the rotation of the rotating shaft under the action of the motion mechanism, thereby shortening the annular wall profile until the base circle radius of the spiral line of the profile reaches its minimum. At this time, the annular wall profile reaches its shortest length, while still tending to maximize the profile (the base circle radius of the spiral line of the profile reaches its maximum length). Thus, the profile can be changed according to the actual working conditions, resulting in lower noise and operating noise in the semi-anechoic chamber; only one motion mechanism is needed to drive it. The rotating shaft is simple to operate, requiring few electrical components and low cost. By winding the main body of the ring wall onto the rotating shaft, the circumference can be changed accordingly when the profile changes. This avoids pressure loss due to changes in the position of the starting end, which could lead to increased gaps with the volute tongue or misalignment between the volute outlet and the cover plate. This ensures the normal operation of the centrifugal fan. The ring wall airbags are tightly attached to the main body of the ring wall, resulting in more uniform force applied to the main body, which helps improve the smoothness of the ring wall. Moreover, the ring wall airbags are lightweight, enabling a lightweight design of the volute assembly. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the volute assembly according to an embodiment of the present utility model;

[0025] Figure 2This is a schematic diagram of the volute assembly according to an embodiment of the present utility model (and...). Figure 1 (Different perspectives);

[0026] Figure 3 for Figure 2 A magnified schematic diagram of part I;

[0027] Figure 4 This is an exploded structural diagram of the volute assembly according to an embodiment of the present utility model;

[0028] Figure 5 for Figure 4 A magnified schematic diagram of part II;

[0029] Figure 6 This is a cross-sectional view of the volute assembly according to an embodiment of the present utility model;

[0030] Figure 7 for Figure 6 A magnified schematic diagram of part III;

[0031] Figure 8 This is a cross-sectional view (innermost state of the profile) of the volute assembly according to an embodiment of the present utility model;

[0032] Figure 9 This is a cross-sectional view (outermost state of the profile) of the volute assembly according to an embodiment of the present invention. Detailed Implementation

[0033] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions.

[0034] In the description of this utility model, 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," and "circumferential," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Since the embodiments disclosed in this utility model can be arranged in different directions, these terms indicating direction are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0035] See Figures 1 to 7A volute assembly for a centrifugal fan, which is mainly used in range hoods, but can also be used in other applications requiring such a power unit.

[0036] The volute assembly includes two spaced-apart cover plates 1, with an annular wall between them. The annular wall includes a volute tongue 21 and a profile adjustment assembly. The profile adjustment assembly includes a rotating shaft 221 and an annular wall body 223, which are independent of each other. The rotating shaft 221 is parallel to the axis of the centrifugal fan and is circumferentially adjacent to the volute tongue 21. Both ends of the rotating shaft 221 are rotatably connected to the cover plates 1 at corresponding positions. To facilitate the installation of the rotating shaft 221, a base 14 extends outward from the outer side of each cover plate 1, and the end of the rotating shaft 221 can be rotatably connected to the base 14. A portion of the annular wall body 223 is wound around the rotating shaft 221, and the wound portion is wound into a cylindrical shape. The end of the annular wall body 223 is connected and fixed to the rotating shaft 221. The unwound portions of the volute tongue 21 and the annular wall body 223 constitute a conventional annular wall, and the profile formed by their combination is the profile of the annular wall. By giving the ring wall a coiled shape, the problem of inconsistent circumference when the volute profile changes can be solved. The ring wall body 223 is made of a deformable material, such as a thin metal sheet.

[0037] The volute assembly also includes a fastening plate 3, which is disposed on the outer side of the ring wall. The fastening plate 3 is parallel to the extension direction of the rotating shaft 221. Both ends of the fastening plate 3 are bent and welded to the cover plate 1 at the corresponding positions to fix it, thereby achieving the fixation of the volute assembly.

[0038] At the end of the annular wall body 223 away from the rotating shaft 221, flanges 224 are formed on opposite sides. Each cover plate 1 has a limiting groove 11 on the side facing the inside of the volute assembly. The limiting groove 11 extends along the width direction of the volute assembly, such as... Figure 6 The flange 224 engages within the limiting groove 11, allowing for linear movement along the groove. Through the cooperation of the flange 224 and the limiting groove 11, the mobility of the annular wall body 223 is ensured, while maintaining the relative position (essentially flush) of this end of the annular wall body 223 with the cover plate 1. This prevents displacement of this end of the annular wall body 223 in the height direction of the volute assembly. The height direction refers to... Figure 6 The up and down directions are shown in the diagram.

[0039] Each cover plate 1 also has a limiting protrusion 12 formed on the side facing inwards from the volute assembly. The limiting protrusion 12 is located radially inwards from the annular wall body 223. Each cover plate 1 also has a limiting flange 13 formed on its outer edge, each flange being formed by bending the edge of the cover plate 1 towards another cover plate 1. The aforementioned annular wall body 223 is located between the limiting protrusion 12 and the limiting flange 13. The limiting protrusion 12 defines the limit position of the annular wall body 223 in radial inward contraction (inner limit), and the limiting flange 13 defines the limit position of the annular wall body 223 in radial outward expansion (outer limit). The positions of the limiting protrusion 12 and the limiting flange 13 can be obtained based on design testing, designed to achieve the lowest noise profile and the lowest operating noise profile for the semi-anechoic chamber.

[0040] The profile adjustment assembly also includes an annular wall airbag 225, which is adhered to the side of the annular wall body 223 facing outwards from the volute assembly. Its shape is adapted to the annular wall body 223, and a portion of it is wound around the rotating shaft 221. The annular wall airbag 225 is filled with gas at a certain pressure. Without external force, the annular wall body 223 tends to maintain the longest profile posture, meaning it can approach or adhere to the limiting flange 13, at which point the base circle radius of the profile's spiral is at its maximum.

[0041] The volute assembly also includes a motion mechanism 4 for driving the movement of the ring wall body 223. The motion mechanism 4 includes a drive mechanism 41 and a transmission mechanism 42 to drive the rotating shaft 221 to rotate. The drive mechanism 41 is preferably a motor, fixedly mounted on the radially outer side of the ring wall. Its mounting method with the ring wall can be the same as that of the rotating shaft 221. The transmission mechanism 42 is preferably a gear set, which may include a primary gear 421 and a final gear 422. The primary gear 421 is mounted on the output shaft of the motor, and the final gear 422 is mounted on the rotating shaft 221. The drive mechanism 41 can be electrically connected to the electrical box of the range hood to realize power supply and control. It is preferably a motor with a clutch.

[0042] To optimize the flow control of the centrifugal fan and further reduce the noise levels in both operating conditions (semi-anechoic chamber and full noise chamber) of the range hood when applied to it, the drive mechanism 41 is energized and de-energized to switch to the profile with the lowest semi-anechoic chamber noise in the semi-anechoic chamber condition and to the profile with the lowest full noise in the full noise chamber condition.

[0043] The logic for implementing the above-mentioned volute component is as follows:

[0044] 1) The profile with the lowest noise in the semi-anechoic chamber (denoted as profile A) and the profile with the lowest operating noise (denoted as profile B) were obtained through testing;

[0045] 2) Based on the above profile parameters, design a limiting protrusion 12 (assuming it corresponds to profile B) and a limiting flange 13 (assuming it corresponds to profile A) on the cover plate 1 of the volute assembly.

[0046] 3) Gas of appropriate pressure is filled into the annular wall airbag 225. The gas pressure inside the airbag 225 causes the annular wall body 223 to tend towards a longer circumference shape, increasing volume and reducing pressure. Therefore, under no applied power condition, the annular wall of the volute assembly is tightly against the limiting flange 13. At this time, the volute profile is close to profile A. (See [reference]) Figure 9 ;

[0047] 4) Set reasonable driving force for the drive mechanism 41 and dimensions for the transmission mechanism 42 (such as gear diameter and number of teeth) to ensure that, under the condition of power applied by the motion mechanism 4, the ring wall body 223 can overcome the air pressure inside the ring wall airbag 225, thereby increasing the number of turns of the winding portion of the ring wall body 223 and the ring wall airbag 225, making the ring wall tightly adhere to the limiting protrusion 12. At this time, the volute profile is close to profile B, and the air pressure inside the ring wall airbag 225 increases. See [reference needed]. Figure 8 ;

[0048] 5) Record the speed range of the range hood under working noise conditions (denoted as n1), and record the approximate speed range of the range hood in the semi-anechoic chamber noise meter (denoted as n2);

[0049] 6) When the range hood is actually working, if the actual speed n is detected to be within the range of n1, the current of the drive mechanism 41 is cut off, and the volute profile is switched to the profile B with lower working noise; if the actual speed n is detected to be within the range of n2, the current of the drive mechanism 41 is turned on, and the volute profile is switched to the profile A with lower semi-anechoic chamber noise.

Claims

1. A centrifugal fan casing assembly, comprising two spaced-apart cover plates (1), with an annular wall between the two cover plates (1), the annular wall including a volute tongue (21); characterized in that: The ring wall also includes a profile adjustment assembly, which includes a rotating shaft (221) and a deformable ring wall body (223). The rotating shaft (221) is parallel to the axis of the centrifugal fan and is adjacent to the volute tongue (21) in the circumferential direction. The two ends of the rotating shaft (221) are rotatably connected to the cover plate (1) at the corresponding positions. A part of the ring wall body (223) is wound around the rotating shaft (221), and the end of the ring wall body (223) is connected and fixed to the rotating shaft (221). The volute assembly also includes a motion mechanism (4) for driving the rotating shaft (221) to rotate, which enables the annular wall body (223) to move radially inward to shorten the annular wall profile; The main body of the annular wall (223) maintains the tendency to maximize the annular wall profile.

2. The volute assembly of the centrifugal fan according to claim 1, characterized in that: The profile adjustment assembly also includes an annular wall airbag (225), which is adhered to the outside of the annular wall body (223). The annular wall airbag (225) causes the annular wall body (223) to maintain the trend of making the annular wall profile the longest.

3. The volute assembly of the centrifugal fan according to claim 1 or 2, characterized in that: The motion mechanism (4) includes a drive mechanism (41) and a transmission mechanism (42) for transmitting the output of the drive mechanism (41) to the rotating shaft (221). The drive mechanism (41) is a motor, and the transmission mechanism (42) is a gear set.

4. The volute assembly of the centrifugal fan according to claim 1 or 2, characterized in that: The volute assembly also includes a fastening plate (3) disposed on the outside of the main body of the ring wall. The fastening plate (3) is parallel to the extension direction of the rotating shaft (221). The two ends of the fastening plate (3) are bent and welded to the cover plate (1) at the corresponding positions.

5. The volute assembly of the centrifugal fan according to claim 4, characterized in that: The two ends of the fastening piece (3) are bent and welded to the cover plate (1) at the corresponding positions.

6. The volute assembly of the centrifugal fan according to claim 1 or 2, characterized in that: A flange (224) is formed at one end of the annular wall body (223) away from the pivot (221). The flange (224) is formed on opposite sides of the annular wall body (223). Each cover plate (1) has a limiting groove (11) on one side facing the inside of the volute assembly. The limiting groove (11) extends along the width direction of the volute assembly. The flange (224) is engaged in the limiting groove (11) and can move linearly along the limiting groove (11).

7. The volute assembly of the centrifugal fan according to claim 1 or 2, characterized in that: Each cover plate (1) also has a limiting protrusion (12) on the side facing the inside of the volute assembly, the limiting protrusion (12) being located radially inside the annular wall body (223).

8. The volute assembly of the centrifugal fan according to claim 1 or 2, characterized in that: Each cover plate (1) also has a limiting flange (13) formed on its outer edge, and each limiting flange (13) is formed by bending the edge of the cover plate (1) toward another cover plate (1).

9. A centrifugal fan, characterized in that: The application uses the volute assembly as described in any one of claims 1 to 8.

10. A range hood, characterized in that: The application includes the centrifugal fan as described in claim 9.

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