A fan and a range hood

Abstract

The utility model relates to a fan, including volute and the impeller of setting in volute, the impeller includes the front disc of setting in the air inlet of volute, sets up the back disc at the back side of front disc and along the circumferential connection between front disc and back disc multiple blades, the cross section of front disc is the curve of inclining to volute, the inner wall on volute front end face has the baffle extending to the both sides of front disc front part along the circumference, and the baffle forms the labyrinth path with front disc between. The fan can effectively inhibit the backflow, reduce the noise. The utility model relates to a range hood including aforementioned fan.

Description

Technical Field

[0001] This utility model relates to a fan, and also to a range hood that uses the fan. Background Technology

[0002] Range hoods have become an indispensable kitchen appliance in modern homes. They operate on the principles of fluid dynamics, using a centrifugal fan installed inside to draw in and exhaust cooking fumes. The centrifugal fan consists of a casing, an impeller housed within the casing, and a motor that drives the impeller. As the impeller rotates, a negative pressure is generated at the center of the fan, drawing in the cooking fumes from below. After being accelerated by the fan, the fumes are collected by the casing and guided outwards.

[0003] To reduce the risk of users bumping their heads and to improve the aesthetics of a slim design, existing range hoods are beginning to use slim fans. For example, Chinese invention patent CN113310085B (application number 202110586605.3) and Chinese utility model patent CN215863629U (application number 202122053725.5) both disclose range hoods that use slim fans.

[0004] Due to the reduced thickness, the air inlet space of thin-type fans is relatively narrow. The presence of the air inlet panel increases turbulence, and the close distance between the fan inlet and the panel partially obstructs the air inlet collector, weakening the overall guiding effect of the air inlet ring and resulting in more vortices in the impeller area. Especially at low flow rates, the impeller load and flow rate are uneven, and instabilities in the impeller flow develop and increase at the boundary positions, leading to more dead zones.

[0005] Furthermore, in fans, there is a gap between the impeller and the inner surface of the volute. In ultra-thin fans, where space is limited, some air forced into the volute's flow channel flows back through this gap into the radially inner region of the impeller blades, creating backflow. This backflow interferes with the airflow drawn in at the inlet, thus generating noise. Even if the impeller's front plate extends into the impeller, it cannot effectively prevent backflow. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a fan that can effectively suppress backflow and reduce noise, in contrast to the above-mentioned prior art.

[0007] The second technical problem to be solved by this utility model is to provide a range hood that uses the aforementioned fan, in contrast to the prior art.

[0008] The technical solution adopted by this utility model to solve the first technical problem mentioned above is as follows: a fan, including a volute and an impeller disposed inside the volute, characterized in that: the impeller includes a front plate disposed at the air inlet of the volute, a rear plate disposed behind the front plate, and a plurality of blades circumferentially connected between the front plate and the rear plate, the cross section of the front plate is a curve inclined inward into the volute, and baffles extend circumferentially on both sides of the front part of the front plate on the inner wall of the front end face of the volute, forming a maze path between the baffles and the front plate.

[0009] Preferably, the cross-section of the front disc is arc-shaped, and the cross-section of the front disc gradually expands radially outward from front to back.

[0010] As an improvement, the baffle located on the radially inner side extends axially, and the front part of the front disc protrudes radially inward to form a flared opening that gradually narrows in the air intake direction between it and the baffle located on the radially inner side.

[0011] As an improvement, the baffle located on the radially outer side is configured to bend and extend in the bending direction of the front disc.

[0012] As an improvement, the blade is attached to the front disc at a position behind the baffle.

[0013] As an improvement, the tip of the blade has a curved surface that is opposite to the bending direction of the front disc cross section in the radially inward direction from the connection point with the front disc.

[0014] To enhance the backflow prevention effect, the front end face of the volute is recessed along the air intake direction and has a groove. The groove is located near the front plate and on the radially outer side of the front plate. The radially inner side wall of the groove forms a baffle, and the radially outer side wall of the groove forms a barrier plate.

[0015] As an improvement, the thickness of the blades gradually decreases in the opposite direction of the air intake axis and in the radial extension direction of the impeller.

[0016] As an improvement, based on the change in blade thickness, a sharp edge is formed at the radially outer position of the front part of the blade.

[0017] The technical solution adopted by this utility model to solve the second technical problem mentioned above is: a range hood, including the aforementioned fan.

[0018] Compared with existing technologies, the advantages of this invention are as follows: The fan in this invention, through the setting of the baffle and the front plate forming a labyrinth path, effectively prevents backflow from the gap between the volute and the impeller, solving the problem of uneven airflow velocity distribution at the inlet. Even the backflow noise problem, which is more prominent in thin fans, can be effectively solved. In addition, the small amount of airflow that flows back through the labyrinth path can also be straightened and aligned with the inlet airflow direction by the guiding effect of the baffle, reducing airflow disturbance and thus reducing noise.

[0019] Due to its structure, this fan is particularly well-suited for slim design. Consequently, range hoods using this fan can meet the requirements of a slim design and effectively reduce operating noise. Attached Figure Description

[0020] Figure 1 This is a perspective view of the fan in an embodiment of this utility model.

[0021] Figure 2 This is a cross-sectional view of the fan in an embodiment of this utility model.

[0022] Figure 3 This is a partial structural diagram of the impeller in an embodiment of the present invention. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0024] like Figures 1 to 3 As shown, the fan in this embodiment includes a volute 1 and an impeller 2 disposed within the volute 1. The impeller 2 includes a front plate 21 disposed at the air inlet of the volute 1, a rear plate 22 disposed behind the front plate 21, and multiple blades 23 circumferentially connected between the front plate 21 and the rear plate 22. Typically, the diameter of the front plate 21 matches the air inlet. To ensure the impeller 2 can rotate without additional mechanical resistance, there is a gap between the front plate 21 and the front end face of the volute 1. As described in the background art, the airflow entering the volute 1 through the impeller 2 inevitably experiences backflow, especially in the gap between the front plate 21 and the volute 1, where the backflow is more pronounced. To avoid this backflow interfering with the noise generated by the new airflow entering the volute 1, this embodiment makes the following structural improvements to the fan to solve the backflow noise problem.

[0025] To reduce air intake resistance and guide the air intake, allowing it to be more smoothly guided into the flow space of the volute 1 under the guidance of the front disc 21, the front disc 21 in this embodiment has a cross-section that is a curve inclined inward towards the volute 1. Specifically, the cross-section of the front disc 21 is arc-shaped and gradually expands radially outward from front to back. Based on the curvature of the cross-section curve of the front disc 21, it guides the air intake towards the inner wall of the volute 1, which is more conducive to the airflow being discharged outward through the volute 1.

[0026] Baffles 11 extend circumferentially from the inner wall of the front face of the volute 1 to both sides of the front of the front plate 21. A winding maze path 100 is formed between the baffles 11 and the front plate 21. Based on the setting of the maze path 100, the difficulty of the airflow in the volute 1 flowing back through the maze path 100 is increased, which will reduce the backflow situation, weaken the interference of the backflow on the new airflow at the air inlet, and reduce the backflow noise.

[0027] The baffle 11 located on the radially outer side is bent and extended in the bending direction of the front disc 21. The baffle 11 located on the radially outer side is located on the inlet side of the return airflow and can be smoothly introduced in accordance with the return flow direction, so that the airflow is smoothly guided along the front disc 21, avoiding interference with the airflow within the labyrinth path 100 and reducing noise.

[0028] Furthermore, the baffle 11 located on the radially inner side extends axially, and the front part of the front disc 21 protrudes radially inward, forming a flared opening 3 that gradually narrows along the air intake direction between it and the baffle 11 located on the radially inner side. Based on this structural configuration, the backflow within the labyrinth path 100 can be output through the flared opening 3. During output, the airflow within the flared opening 3 is contracted, increasing the backflow velocity. Simultaneously, under the guidance of the baffle 11 on the radially inner side, it converges into the newly entering airflow of the fan, avoiding interference with the newly entering airflow and reducing noise problems caused by backflow interfering with the newly entering airflow.

[0029] To enhance the backflow prevention effect, a groove 12 is recessed on the front end face of the volute 1 along the air intake direction. The groove 12 is located near the front plate 21 and on the radial outer side of the front plate 21. A baffle 11 is formed on the radial inner side wall of the groove 12, and a barrier plate 13 is formed on the radial outer side wall of the groove 12.

[0030] Furthermore, the blade 23 is connected to the front disc 21 and located behind the baffle 11. After the airflow is guided by the front disc 21, it enters the airflow space of the volute 1 through the action of the blade 23. In this embodiment, the front end of the blade 23 has a curved surface 231 in the radially inward direction from the connection point with the front disc 21, which is opposite to the curvature direction of the cross section of the front disc 21. That is, from the connection point between the front end of the blade 23 and the front disc 21, the curve of the curved surface 231 is mirror-symmetrical to the cross section curve of the front disc 21.

[0031] The aforementioned baffle 11 can block most of the backflow airflow, effectively suppressing the airflow entering the volute 1 from flowing back into the impeller 2 through the labyrinth path 100, thereby reducing backflow interference noise. Even if a small amount of airflow flows back from the volute 1 into the labyrinth path 100, it is contracted and straightened when it passes through the outlet end of the labyrinth path 100, thus reducing the disturbance in the airflow. The airflow is released to the leading edge of the blade 23 in a state where the disturbance has been reduced, and the curved surface 231 at the leading edge of the blade 23 can also reduce noise.

[0032] Furthermore, the rear plate 22 of impeller 2 is relatively enclosed due to the drive structure. During operation, after the airflow enters impeller 2, it is radially discharged outward under the action of blades 23. Especially for thin-walled fans, the airflow path changes with a large curvature, making secondary vortices prone to occur at the rear plate 22 of impeller 2. Based on the airflow direction, the airflow is relatively small at the front of the impeller 2 inlet and relatively large at the rear of the impeller 2 inlet.

[0033] like Figure 3 As shown, in this embodiment, the thickness of the blade 23 gradually decreases along the opposite direction of the inlet air axis and along the radial outward extension direction of the impeller 2. Based on the change in blade 23 thickness, a sharp edge 232 is formed at the radially outer position of the front part of the blade 23. Since the edge 232 is a very thin and sharp part, the resistance to the incoming airflow is very small, increasing static pressure while reducing noise, that is, increasing the airflow rate entering the impeller 2 with low noise. At the same time, the change in blade 23 thickness matches the distribution of airflow rate in the impeller 2 along the inlet air axis, meeting the different airflow discharge requirements at different positions along the inlet air axis, minimizing the power consumption of the fan, reducing secondary eddies, and reducing operating noise.

[0034] The fan in this invention, through the arrangement of the baffle 11 and the front plate 21, forms a labyrinth path 100, effectively preventing backflow from the gap between the volute 1 and the impeller 2, and solving the problem of uneven airflow velocity distribution at the inlet. Even the backflow noise problem, which is more prominent in thin fans, can be effectively resolved. Furthermore, the small amount of airflow that returns through the labyrinth path 100 can be straightened and aligned with the inlet flow direction by the guiding effect of the baffle 11, reducing airflow turbulence and thus reducing noise.

[0035] This fan is better suited to the working conditions of thin fans, which is beneficial for the design of thin fans.

[0036] This utility model also relates to a range hood, including a housing and the aforementioned fan disposed within the housing. This range hood has low noise, a larger smoke extraction capacity per unit power consumption, and solves the problem of applying thin fans within it, making it highly advantageous for thin fan design.

[0037] In the specification and claims of this utility model, terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," are used to describe various exemplary structural parts and elements of the invention. However, the use of these terms is merely for illustrative purposes and is based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this invention can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be considered as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

Claims

1. A fan, comprising a volute (1) and an impeller (2) disposed within the volute (1), characterized in that: The impeller (2) includes a front plate (21) disposed at the air inlet of the volute (1), a rear plate (22) disposed behind the front plate (21), and a plurality of blades (23) circumferentially connected between the front plate (21) and the rear plate (22). The cross section of the front plate (21) is a curve inclined inward into the volute (1). Baffles (11) extend circumferentially on both sides of the front part of the front end face of the volute (1) to the front of the front plate (21). A maze path (100) is formed between the baffles (11) and the front plate (21).

2. The fan according to claim 1, characterized in that: The front disc (21) has an arc-shaped cross section, and the cross section of the front disc (21) gradually expands radially outward from front to back.

3. The fan according to claim 2, characterized in that: The baffle (11) located on the radial inner side extends axially, and the front part of the front disc (21) is radially protruding inward to form a flared mouth (3) that gradually narrows in the air intake direction between it and the baffle (11) located on the radial inner side.

4. The fan according to claim 2, characterized in that: The baffle (11) located on the radially outer side is configured to bend and extend in the bending direction of the front disc (21).

5. The fan according to any one of claims 2 to 4, characterized in that: The blade (23) is connected to the front disc (21) at a position behind the baffle (11).

6. The fan according to claim 5, characterized in that: The front end of the blade (23) has a curved surface (231) that is opposite to the bending direction of the cross section of the front disc (21) in the radially inward direction from the connection point with the front disc (21).

7. The fan according to any one of claims 1 to 4, characterized in that: The front end face of the volute (1) is recessed along the air intake direction and has a groove (12). The groove (12) is located near the front plate (21) and is located on the radial outer side of the front plate (21). The side wall located on the radial inner side of the groove (12) forms a baffle (11), and the side wall located on the radial outer side of the groove (12) forms a barrier plate (13).

8. The fan according to any one of claims 1 to 4, characterized in that: The thickness of the blade (23) gradually decreases in the opposite direction of the air intake axis and in the radial extension direction of the impeller (2).

9. The fan according to claim 8, characterized in that: Based on the thickness variation of the blade (23), a sharp edge (232) is formed at the radially outer position of the front part of the blade (23).

10. A range hood, characterized in that: Includes the wind turbine as described in any one of claims 1 to 9.

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