Centrifugal fan and range hood applying same

Abstract

The centrifugal fan comprises a volute, an impeller arranged in the volute and a motor used for driving the impeller to rotate, the volute comprises a first cover plate and a second cover plate which are arranged in a spaced mode, a first air inlet is formed in the first cover plate, and a second air inlet is formed in the second cover plate. A second air inlet is formed in the second cover plate; the impeller comprises a first end ring, a second end ring and blades arranged between the two end rings; an annular guide groove is formed in the side, facing the corresponding cover plate, of each end ring of the impeller, the motor is located on the outer side of the impeller, and the projection of the motor on the plane perpendicular to the axis of the centrifugal fan is located outside the projection of the two air inlets of the impeller and the volute on the plane perpendicular to the axis of the centrifugal fan. The centrifugal fan further comprises a first driving wheel and a second driving wheel, and each driving wheel is clamped in the corresponding guide groove and can drive the impeller to rotate when the motor drives the impeller to rotate.

Description

Technical Field

[0001] The utility model relates to a power device, in particular to a centrifugal fan and a range hood using the centrifugal fan. Background Art

[0002] Range hoods have become one of the indispensable kitchen appliances in modern families. Usually, range hoods include ceiling-suction type and side-suction type. The ceiling-suction range hood is increasingly widely used due to its advantages such as being neat, light and small in space.

[0003] For example, a Chinese patent application numbered 201310742965.3 discloses a centrifugal fan for a range hood with a double air inlet structure. This type of fan usually has a middle disk in the middle of the impeller, and a motor on the middle and rear side of the impeller. The output shaft of the motor is connected to the axis of the middle disk to drive the impeller to rotate. Due to the existence of the middle disk structure, the fluid will hit the middle disk during the process of being sucked into the impeller, causing air volume loss, and at the same time, vortices will be generated, resulting in increased aerodynamic noise. In addition, due to the existence of the middle disk, the airflow at the blade outlet is unevenly distributed along the axial direction, usually from small to large and then decreasing from the front circle to the middle disk, and from small to large and then decreasing from the middle disk to the rear circle. The uneven airflow will cause the impeller to vibrate more and increase aerodynamic noise. In addition, the unevenly distributed airflow has a strong impact on the volute tongue, making the gas flow near the volute tongue more complicated, which has a greater impact on the performance of the fan.

[0004] At the same time, the motor is usually set at the rear air inlet, and the output shaft of the motor is connected to the middle disk to drive the impeller to rotate. Due to the presence of the motor, the wind resistance of the rear air inlet becomes larger, and the air volume sucked from the rear air inlet is reduced. The air volume of the front air inlet is large and the air volume of the rear air inlet is small, which further causes the impeller airflow to be unevenly distributed, which in turn causes the impeller to further shake, resulting in increased noise. Utility Model Content

[0005] The first technical problem to be solved by the utility model is to provide a centrifugal fan for the above-mentioned deficiencies in the prior art, which can ensure that the impeller reduces vibration during high-speed rotation, thereby reducing air volume loss and aerodynamic noise.

[0006] The second technical problem to be solved by the utility model is to provide a centrifugal fan for the above-mentioned deficiencies in the prior art, which accelerates the airflow from the fan volute tongue to the outlet and reduces the backflow at the volute tongue.

[0007] The third technical problem to be solved by the present invention is to provide a range hood using the centrifugal fan.

[0008] The utility model solves the above-mentioned first technical problem by adopting the following technical solution: a centrifugal fan, comprising a volute, an impeller arranged in the volute, and a motor for driving the impeller to rotate, the volute comprising a first cover plate and a second cover plate arranged at intervals, the first cover plate being provided with a first air inlet, the second cover plate being provided with a second air inlet, the impeller comprising a first end ring, a second end ring, and blades arranged between the two end rings; the characteristics are:

[0009] Each end ring of the impeller is formed with an annular guide groove on one side facing the corresponding cover plate, the motor is located outside the impeller, and the projection of the motor on a plane perpendicular to the axis of the centrifugal fan is outside the projection of the two air inlets of the impeller and the volute on a plane perpendicular to the axis of the centrifugal fan;

[0010] The centrifugal fan further comprises a first driving wheel and a second driving wheel, each driving wheel is clamped in a guide groove and can drive the impeller to rotate when the motor drives the impeller to rotate.

[0011] The motor is arranged outside the impeller, and through the setting of the motor position, the impeller does not need a center disk to realize double air inlet, and the motor and the driving wheel will not block the two air inlets on the volute and the air inlet channel of the impeller. Therefore, the two air inlets intake air evenly, and the impeller airflow is evenly distributed, which can ensure that the impeller reduces jitter during high-speed rotation, thereby reducing air volume loss and reducing aerodynamic noise.

[0012] To facilitate the motor to drive the two driving wheels to rotate, the centrifugal fan also includes a gear set, which includes a first gear, a second gear, a third gear, a fourth gear and a fifth gear. The first gear is driven to rotate by the motor, the second gear is meshed with the first gear, the third gear is meshed with the second gear, the fourth gear is meshed with the fifth gear, the third gear and the fourth gear are coaxially arranged and linked, the first driving wheel is coaxially arranged with the second gear and rotates synchronously, the second driving wheel is coaxially arranged with the fifth gear and rotates synchronously, and the rotation axis of the first driving wheel and the second driving wheel is perpendicular to the axis of the centrifugal fan.

[0013] Preferably, each gear of the gear set is a bevel gear, the rotation axis of the motor is parallel to the axis of the centrifugal fan, the rotation axes of the first gear, the third gear and the fourth gear are parallel to the axis of the centrifugal fan, and the rotation axes of the second gear and the fifth gear are perpendicular to the axis of the centrifugal fan.

[0014] In order to facilitate the coaxial linkage of the third gear and the fourth gear, the third gear and the fourth gear are connected via a column.

[0015] To facilitate defining the position of each gear, a first fixed seat and a second fixed seat are respectively provided at both ends of the column, the first fixed seat is fixed to the inner side of the first cover plate, the second fixed seat is fixed to the inner side of the second cover plate, the first gear, the second gear and the third gear are rotatably arranged in the first fixed seat, and the fourth gear and the fifth gear are rotatably arranged in the second fixed seat.

[0016] Preferably, the first driving wheel and the second gear are connected via a first connecting rod, and the second driving wheel and the fifth gear are connected via a second connecting rod.

[0017] In order to further reduce the vibration of the impeller, the first end ring is rotatably supported on the inner side of the first cover plate, and the second end ring is rotatably supported on the inner side of the second cover plate.

[0018] Furthermore, support wheels are respectively arranged on the inner sides of the first cover plate and the second cover plate of the volute, and the support wheels are movably matched with the guide grooves so that the impeller can only rotate relative to the volute. The support wheels are used to limit the axial positions of the front and rear end circles of the impeller, further ensuring that the impeller has less vibration during high-speed rotation, thereby reducing air volume loss and aerodynamic noise.

[0019] Preferably, at least three supporting wheels are provided on each cover plate, and the supporting wheels on each cover plate are arranged at intervals along the circumference of the guide groove.

[0020] The technical solution adopted by the utility model to solve the above-mentioned second technical problem is: the volute also includes a volute tongue and an air outlet, and the centrifugal fan also includes a cylindrical column, which can rotate around its own axis and the rotation axis is parallel to the axis of the centrifugal fan, and the column is arranged at a position close to the air outlet in the gap between the volute tongue and the impeller.

[0021] In order to solve the problems of complex fluid flow at the volute tongue and gas impact on the volute tongue affecting the fan performance, a column is set at the front side of the gap between the volute tongue and the impeller (that is, the side of the gap close to the air outlet). The column is composed of a vortex ring guide column. The vortex ring guide column rotates at high speed in the airflow, and the surrounding air will also rotate due to friction and the viscosity of the gas, thus generating a rotating vortex ring radiating outward, which increases the fluid velocity on one side of the cylinder and reduces the fluid velocity on the other side, so that the fluid can be directed to the air outlet to reduce backflow.

[0022] Preferably, the centrifugal fan further comprises a gear set, the gear set comprises a first gear, a second gear, a third gear, a fourth gear and a fifth gear, the first gear is driven to rotate by a motor, the second gear is meshed with the first gear, the third gear is meshed with the second gear, the fourth gear is meshed with the fifth gear, the third gear and the fourth gear are respectively arranged at two axial ends of the column, the first driving wheel is coaxially arranged with the second gear and rotates synchronously, the second driving wheel is coaxially arranged with the fifth gear and rotates synchronously, and the rotation axes of the first driving wheel and the second driving wheel are perpendicular to the axis of the centrifugal fan. Thus, the impeller and the column share a common motor drive, which simplifies the structure.

[0023] The technical solution adopted by the utility model to solve the third technical problem is: a range hood, characterized in that: the centrifugal fan as described above is applied.

[0024] Compared with the prior art, the advantages of the utility model are: by arranging the motor outside the impeller and by setting the position of the motor, the impeller does not need a central disk to achieve double air intake, and the motor and the driving wheel will not block the two air inlets on the volute and the air inlet channel of the impeller, so that the two air inlets intake air evenly, and the impeller airflow is evenly distributed, which can ensure that the impeller reduces jitter during high-speed rotation, thereby reducing wind volume loss and reducing aerodynamic noise; in order to address the problems of complex fluid flow at the volute tongue and gas impact on the volute tongue causing the fan performance to be affected, a column is arranged on the front side of the gap between the volute tongue and the impeller (that is, the side of the gap close to the air outlet), and the column is constructed as a vortex ring guide column. The vortex ring guide column rotates at high speed in the airflow, and the surrounding air will also rotate due to friction and the viscosity of the gas, that is, a rotating vortex ring radiating outward is generated, which increases the fluid velocity on one side of the cylinder and reduces the fluid velocity on the other side, that is, the fluid can be guided to the air outlet to reduce backflow. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a centrifugal fan according to an embodiment of the present utility model;

[0026] Figure 2 This is a schematic diagram of the exploded structure of a centrifugal fan according to an embodiment of the utility model;

[0027] Figure 3 A schematic diagram of a hidden volute of a centrifugal fan according to an embodiment of the utility model;

[0028] Figure 4 A schematic diagram of a vortex ring guide assembly of a centrifugal fan according to an embodiment of the utility model;

[0029] Figure 5 This is a cross-sectional view (axial cross-section) of a centrifugal fan according to an embodiment of the present utility model;

[0030] Figure 6It is a cross-sectional view (radial cross-section) of the centrifugal fan according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0031] Embodiments of the present utility model are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions.

[0032] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Since the embodiments disclosed in the present utility model can be set in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features.

[0033] See also Figure 1 to Figure 6 The invention discloses a centrifugal fan, which can be mainly used for range hoods, especially top suction range hoods, and can also be used in other occasions requiring such a power device.

[0034] The centrifugal fan is a double-inlet fan, including a volute 1, an impeller 2 arranged in the volute 1, and a motor 3 for driving the impeller 2 to rotate, wherein a first air inlet 11 and a second air inlet 12 are opened on the volute 1, and the volute 1 includes a first cover plate 13 and a second cover plate 14 arranged at intervals, and an annular wall 15 is arranged between the first cover plate 13 and the second cover plate 14, and the above-mentioned first air inlet 11 is formed on the first cover plate 13, and the second air inlet 12 is formed on the second cover plate 14.

[0035] The impeller 2 includes a first end ring 21, a second end ring 22 and a plurality of blades 23 arranged between the two end rings. The first end ring 21 corresponds to the first cover plate 13 of the volute 1, and the second end ring 22 corresponds to the second cover plate 14 of the volute 1. Air can enter the space enclosed by the first end ring 21 and the second end ring 22 of the impeller 2. An annular guide groove 24 is also arranged on each end ring of the impeller 2 (the side away from the other end ring), and support wheels 16 are respectively arranged on the inner side of the first cover plate 13 and the second cover plate 14 of the volute 1 (the inner side here refers to the side facing the inside of the volute 1) at the position of the guide groove 24. The support wheel 16 is rotatably matched with the guide groove 24, so as to limit the impeller 2 so that the impeller 2 can rotate relative to the volute 1 (the support wheel 16 and the guide groove 24 are rotatably matched) but cannot move along the axis X of the centrifugal fan.

[0036] At least three support wheels are preferably provided on each cover plate, and are arranged at intervals, preferably evenly spaced, along the circumference of the guide groove 24. Under the action of each support wheel, the impeller 2 is rolled and fixed by the support wheel 16, so that the shaking of the impeller 2 is reduced.

[0037] The volute 1 also includes a volute tongue 17 and an air outlet 18. The volute tongue 17 is formed on the annular wall 15. The air outlet 18 is surrounded by the first cover plate 13, the second cover plate 14 and the annular wall 15. The centrifugal fan also includes a column 41, which is preferably arranged at a position close to the air outlet 18 at the gap between the volute tongue 17 and the impeller 2. The column 41 is cylindrical and can rotate around its own axis. Its rotation axis is parallel to the axis X of the centrifugal fan. One of the axial ends of the column 41 is connected to the first cover plate 13 of the volute 1 through the first fixed seat 421, and the other end of the column 41 is connected to the second cover plate 14 of the volute 1 through the second fixed seat 422. Each fixed seat is fixed to the inner side of the corresponding cover plate. The column 41 is located on the outer side of the impeller 2.

[0038] The centrifugal fan further includes a first driving wheel 441, a second driving wheel 442 and a gear set, wherein the gear set includes a first gear 451, a second gear 452, a third gear 453, a fourth gear 454 and a fifth gear 455, wherein the motor 3 may be arranged on one of the cover plates, located radially outside the impeller 2, the axis of the motor 3 is parallel to the axis of the impeller 2 (i.e., the axis X of the centrifugal fan), i.e., the motor 3 will not face the air inlet of the impeller 2, the first gear 451, the second gear 452 and the third gear 453 are rotatably arranged in the first fixed seat 421, and the fourth gear 454 and the fifth gear 455 are rotatably arranged in the second fixed seat 422. The gears of the gear set are preferably bevel gears. The third gear 453 and the fourth gear 454 are respectively arranged at the two axial ends of the column 41. The motor 3 can be arranged adjacent to the first fixed seat 421 to drive the first gear 451 to rotate, the second gear 452 is meshed with the first gear 451, the third gear 453 is meshed with the second gear 452, and the fourth gear 454 is meshed with the fifth gear 455. The motor 3 is arranged on the outside of the first cover plate 13, and the projection of the motor 3 on the plane perpendicular to the axis of the centrifugal fan is located outside the projection of the two air inlets of the impeller 2 and the volute 1 on the plane perpendicular to the axis of the centrifugal fan, thereby not blocking the air inlet and the ventilation channel of the impeller 2. In addition, the impeller 2 and the column 41 are driven by the same motor 3, which also simplifies the structure.

[0039] The first driving wheel 441 is arranged adjacent to the first fixed seat 421, and is coaxially arranged with the second gear 452 to rotate synchronously, and the first driving wheel 441 and the second gear 452 can be connected through the first connecting rod 431. The second driving wheel 442 is arranged adjacent to the second fixed seat 422, and is coaxially arranged with the fifth gear 455 to rotate synchronously, and the second driving wheel 442 and the fifth gear 455 can be connected through the second connecting rod 432. The first driving wheel 441 is clamped in the guide groove 24 of the first end ring 21, and the second driving wheel 442 is clamped in the guide groove 24 of the second end ring 22. When the two driving wheels rotate in the same direction, the impeller 2 can be driven to rotate. Since the first driving wheel 441 and the second driving wheel 442 are both connected to the radial outer side of the impeller 2 from the guide ring 24, the air inlet and the ventilation channel of the impeller 2 will not be blocked.

[0040] Thus, when the motor 3 drives the first gear 451 to rotate, the second gear 452 and the first driving wheel 441 can be driven to rotate, and the second gear 452 can drive the third gear 453 to rotate, thereby rotating the column 41, thereby rotating the fourth gear 454, and then driving the fifth gear 455 and the second driving wheel 442. The rotation axis (output shaft) of the motor 3 is parallel to the axis X of the centrifugal fan, and the rotation axes of the first gear 451, the third gear 453, the column 41, and the fourth gear 454 are all parallel to the axis X of the centrifugal fan, and the rotation axes of the second gear 452, the fifth gear 455, the first driving wheel 441, and the second driving wheel 442 are perpendicular to the axis X of the centrifugal fan.

[0041] Driven by the first driving wheel 441 and the second driving wheel 442, the impeller 2 starts to rotate, generating fluid flow. Figure 5 , the arrows indicate the oil smoke flow path, and the oil smoke enters from two air inlets. Figure 6 , the arrow inside the cylinder 41 indicates the direction of rotation of the cylinder 41, and the arrow outside the cylinder 41 indicates the flow path of the oil fume airflow. With the cooperation of the gear set, when the impeller 2 rotates clockwise, the cylinder 41 also rotates clockwise, and as the speed of the impeller 2 increases and the fluid increases, the speed of the cylinder 41 will also increase, and the cylinder 41 constitutes a vortex ring guide column. Assume that the wind speed generated by the impeller 2 is V, the radius of the cylinder 41 is r, and the angular velocity of rotation is ω. At this time, the air in contact with the surface of the cylinder 41 moves around the cylindrical surface. It is approximately assumed that the air at the surface of the cylinder is relatively stationary with the surface of the cylinder and rotates around the axis at an angular velocity ω. It can be concluded that the wind speed above the cylinder 41 is V1=V+rω, and the wind speed below the cylinder 41 is V2=V-rω, that is, the wind speed above the cylinder 41 increases, while the wind speed below decreases accordingly. That is to say, the fluid is deflected to flow toward the air outlet 18 of the volute 1 to improve the fluid flow at the volute tongue 17, which has a rectifying effect, can effectively reduce flow loss and increase air volume.

[0042] From the above, it can be seen that the centrifugal fan of the utility model is a double-inlet fan, and the motor 3 and the transmission mechanism will not block the two air inlets and the air inlet channels of the impeller 2. The two air inlets intake air evenly, and the impeller airflow is evenly distributed, which can reduce impeller vibration and reduce noise.

Claims

1. A centrifugal fan, comprising a volute (1), an impeller (2) arranged in the volute (1), and a motor (3) for driving the impeller (2) to rotate, the volute (1) comprising a first cover plate (13) and a second cover plate (14) arranged at an interval, the first cover plate (13) being provided with a first air inlet (11), the second cover plate (14) being provided with a second air inlet (12), the impeller (2) comprising a first end ring (21), a second end ring (22), and blades (23) arranged between the two end rings; characterized in that: Each end ring of the impeller (2) is formed with an annular guide groove (24) on one side facing the corresponding cover plate, the motor (3) is located outside the impeller (2), and the projection of the motor (3) on a plane perpendicular to the axis (X) of the centrifugal fan is located outside the projection of the impeller (2) and the two air inlets of the volute (1) on a plane perpendicular to the axis (X) of the centrifugal fan; The centrifugal fan further comprises a first driving wheel (441) and a second driving wheel (442), each driving wheel being clamped in a guide groove (24) and capable of driving the impeller (2) to rotate when the motor (3) drives the impeller (2) to rotate.

2. The centrifugal fan according to claim 1, characterized in that: The centrifugal fan further comprises a gear set, which comprises a first gear (451), a second gear (452), a third gear (453), a fourth gear (454) and a fifth gear (455); the first gear (451) is driven to rotate by the motor (3); the second gear (452) is meshed with the first gear (451); the third gear (453) is meshed with the second gear (452); the fourth gear (454) is meshed with the fifth gear (455); the third gear (453) and the fourth gear (454) are coaxially arranged and linked; the first driving wheel (441) and the second gear (452) are coaxially arranged and rotate synchronously; the second driving wheel (442) and the fifth gear (455) are coaxially arranged and rotate synchronously; the rotation axes (X) of the first driving wheel (441) and the second driving wheel (442) are perpendicular to the axis (X) of the centrifugal fan.

3. The centrifugal fan according to claim 2, characterized in that: Each gear of the gear set is a bevel gear, the rotation axis of the motor (3) is parallel to the axis (X) of the centrifugal fan, the rotation axes of the first gear (451), the third gear (453) and the fourth gear (454) are all parallel to the axis (X) of the centrifugal fan, and the rotation axes of the second gear (452) and the fifth gear (455) are perpendicular to the axis (X) of the centrifugal fan.

4. The centrifugal fan according to claim 2, characterized in that: The third gear (453) and the fourth gear (454) are connected via a column (41).

5. The centrifugal fan according to claim 4, characterized in that: A first fixed seat (421) and a second fixed seat (422) are respectively provided at both ends of the column (41); the first fixed seat (421) is fixed to the inner side of the first cover plate (13); the second fixed seat (422) is fixed to the inner side of the second cover plate (14); the first gear (451), the second gear (452) and the third gear (453) are rotatably arranged in the first fixed seat (421); and the fourth gear (454) and the fifth gear (455) are rotatably arranged in the second fixed seat (422).

6. The centrifugal fan according to claim 2, characterized in that: The first driving wheel (441) and the second gear (452) are connected via a first connecting rod (431), and the second driving wheel (442) and the fifth gear (455) are connected via a second connecting rod (432).

7. The centrifugal fan according to claim 1, characterized in that: The first end ring (21) is rotatably supported on the inner side of the first cover plate (13), and the second end ring (22) is rotatably supported on the inner side of the second cover plate (14).

8. The centrifugal fan according to claim 7, characterized in that: Support wheels (16) are respectively arranged inside the first cover plate (13) and the second cover plate (14) of the volute (1), and the support wheels (16) are movably matched with the guide groove (24) so ​​that the impeller (2) can only rotate relative to the volute (1).

9. The centrifugal fan according to claim 8, characterized in that: At least three support wheels (16) are arranged on each cover plate, and the support wheels (16) on each cover plate are arranged at intervals along the circumference of the guide groove (24).

10. The centrifugal fan according to claim 1, characterized in that: The volute (1) further comprises a volute tongue (17) and an air outlet (18), and the centrifugal fan further comprises a cylindrical column (41), wherein the column (41) can rotate around its own axis (X) and the rotation axis (X) is parallel to the axis (X) of the centrifugal fan, and the column (41) is arranged at a position close to the air outlet (18) at the gap between the volute tongue (17) and the impeller (2).

11. The centrifugal fan according to claim 10, characterized in that: The centrifugal fan further comprises a gear set, which comprises a first gear (451), a second gear (452), a third gear (453), a fourth gear (454) and a fifth gear (455); the first gear (451) is driven to rotate by the motor (3); the second gear (452) is meshed with the first gear (451); the third gear (453) is meshed with the second gear (452); the fourth gear (454) is meshed with the fifth gear (455); the third gear (453) and the fourth gear (454) are respectively arranged at two axial ends of the column (41); the first driving wheel (441) and the second gear (452) are coaxially arranged to rotate synchronously; the second driving wheel (442) and the fifth gear (455) are coaxially arranged to rotate synchronously; the rotation axes (X) of the first driving wheel (441) and the second driving wheel (442) are perpendicular to the axis (X) of the centrifugal fan.

12. A range hood, characterized in that: The invention relates to a centrifugal fan as claimed in any one of claims 1 to 11.

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