High-impedance negative pressure fan capable of reducing wind loss

Abstract

The utility model provides a high-impedance negative pressure fan capable of reducing wind loss, which comprises a fan shell, and a motor support for fixing a motor is fixedly arranged on the inner wall of the fan shell. A rotating shaft of the motor is fixedly connected with the impeller through a fixing flange, an air volume loss stopping disc is coaxially arranged at the axis of the impeller, and the maximum radius of the air volume loss stopping disc is larger than the radius of the blade root of the impeller. According to the negative pressure fan, the air volume loss stopping disc is arranged at the blade root of the impeller on one side of the air outlet, so that the proportion of airflow flowing back to the other side of the impeller from the blade root can be reduced, air loss is reduced, and the air supply efficiency is improved. And the flexible sealing rings arranged between the blade tips of the blades and the shell can achieve the dynamic sealing effect with the blades, airflow backflow is reduced, and the air supply efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of negative pressure fan technology, specifically a negative pressure fan with high impedance to reduce wind loss. Background Technology

[0002] Fans are widely used in production and daily life, providing the necessary wind power quickly to meet the wind power needs of production and daily life. During the rotation of a fan, airflow enters from one end and is blown out at a higher speed from the other end, achieving the effect of air delivery.

[0003] When a fan rotates, the air pressure at the inlet is generally negative, while the air pressure at the outlet is generally positive. During the impeller's rotation, the speed is highest at the blade tip and lowest at the blade root. Therefore, the airflow velocity and pressure at the blade root are relatively low. This causes the airflow at the outlet to easily flow backward through the blade root back to the inlet, resulting in a loss of airflow and failing to meet operational requirements.

[0004] In addition, during the production process, the impeller of the fan is usually a one-piece structure, which often has a certain amount of imbalance. This imbalance causes the impeller to vibrate when rotating. The vibration is transmitted to the fan casing through the connection, which further amplifies the vibration and noise, greatly affecting the user experience of the fan.

[0005] Therefore, there is an urgent need for a negative pressure fan with low wind loss, high air delivery efficiency, low vibration and low noise. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a negative pressure fan with high impedance to reduce wind loss, so as to solve the problems of airflow backflow, large wind loss, low air delivery efficiency, large vibration and noise in the prior art.

[0007] This utility model provides a negative pressure fan with high impedance to reduce wind loss. The negative pressure fan includes: a fan housing, and a motor bracket for fixing a motor is fixedly installed on the inner wall of the fan housing; the motor shaft is fixedly connected to an impeller through a fixed flange, and an airflow loss prevention disc is coaxially installed at the shaft center of the impeller, the maximum radius of the airflow loss prevention disc being larger than the radius at the blade root of the impeller.

[0008] Furthermore, the axial cross-section of the airflow stop plate is trapezoidal, and the airflow stop plate extends outward along the axial and radial directions from the connection point with the impeller.

[0009] Furthermore, the impeller includes multiple independent blades, which are evenly fixed around the circumference of the fixed flange; a hub is provided at the root of each blade, and the hubs of the multiple blades are connected and fixed to the fixed flange.

[0010] In one embodiment, the air volume loss prevention plate is integrally connected to the fan blade.

[0011] In one embodiment, the air volume loss prevention disc is fixedly connected to the hub of the fan blade or the fixed flange by a fastener.

[0012] In one embodiment, a dynamic sealing structure is provided between the fan blade and the inner wall of the fan housing; the dynamic sealing structure consists of a blade sealing ring disposed at the tip of the fan blade and a flexible sealing ring disposed on the inner wall of the fan housing, wherein the blade sealing ring is capable of moving contact with the flexible sealing ring.

[0013] In one embodiment, a dynamic sealing structure is provided between the fan blade and the inner wall of the fan housing; the dynamic sealing structure consists of the blade tip of the fan blade and a flexible sealing ring disposed on the inner wall of the fan housing, and the blade tip of the fan blade can move and contact the flexible sealing ring.

[0014] This utility model provides a negative pressure fan with high impedance to reduce wind loss. The negative pressure fan includes: a fan housing, a motor bracket for fixing a motor is fixedly installed on the inner wall of the fan housing; the motor shaft is fixedly connected to an impeller through a fixed flange; a bracket is fixedly connected to the inner wall of the fan housing at the air outlet, and an airflow loss prevention disc is fixedly installed on the bracket. The airflow loss prevention disc is coaxially arranged with the impeller but does not contact the impeller, and the maximum radius of the airflow loss prevention disc is greater than the radius at the blade root of the impeller.

[0015] Furthermore, the impeller includes multiple independent blades, which are evenly fixed around the circumference of the fixed flange; a hub is provided at the root of each blade, and the hubs of the multiple blades are connected and fixed to the fixed flange.

[0016] Furthermore, a dynamic sealing structure is provided between the fan blade and the inner wall of the fan housing; the dynamic sealing structure consists of the blade tip of the fan blade and a flexible sealing ring disposed on the inner wall of the fan housing, and the blade tip of the fan blade can move and contact the flexible sealing ring.

[0017] As can be seen from the above embodiments, the high-impedance negative pressure fan with reduced wind loss provided by this utility model has at least the following advantages: The negative pressure fan, by setting an airflow loss-prevention disc at the blade root of the impeller on one side of the air outlet, can reduce the proportion of airflow returning from the blade root to the other side of the impeller, thereby reducing wind loss and improving air delivery efficiency. Furthermore, the flexible sealing ring set between the blade tip and the housing can achieve a dynamic sealing effect with the blade, reducing airflow backflow and improving air delivery efficiency.

[0018] In addition, the negative pressure fan uses split blades. Split blades can reduce the weight difference between blades by using the same set of molds during the production of the blades. After the impeller is assembled, the vibration caused by the center of gravity deviation is smaller when it rotates.

[0019] It should be understood that the above general description and the following specific embodiments are merely exemplary and illustrative, and do not limit the scope of the present invention. Attached Figure Description

[0020] The accompanying drawings are part of the specification of this utility model and illustrate exemplary embodiments of the utility model. The drawings, together with the description in the specification, are used to illustrate the principles of this utility model.

[0021] Figure 1 This is a cross-sectional view of Embodiment 1 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0022] Figure 2 This is a front view of Embodiment 1 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0023] Figure 3 A perspective view of Embodiment 1 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0024] Figure 4 The impeller structure diagram is shown in Embodiment 1 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0025] Figure 5 The impeller of the negative pressure fan with high impedance and reduced wind loss provided by this utility model is shown in the second embodiment.

[0026] Figure 6 This is a front view of the fan blade of a negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0027] Figure 7 A partial cross-sectional view of the blade tip of a negative pressure fan blade embodiment 1 for reducing wind loss with high impedance provided by this utility model.

[0028] Figure 8The front view of the fan blade of the negative pressure fan with high impedance and reduced wind loss provided by this utility model is shown in Embodiment 2.

[0029] Figure 9 A partial sectional view of the blade tip of the fan blade of the negative pressure fan with high impedance and reduced wind loss provided by this utility model, according to Embodiment 2.

[0030] Figure 10 The front view of the fan blade of the negative pressure fan with high impedance and reduced wind loss provided by this utility model is shown in Embodiment 3.

[0031] Figure 11 A partial cross-sectional view of the blade tip of the negative pressure fan blade of Embodiment 3, which provides a high impedance and reduces wind loss according to this utility model.

[0032] Figure 12 The front view of the fan blade of the negative pressure fan with high impedance and reduced wind loss provided by this utility model is shown in Embodiment 4.

[0033] Figure 13 A partial sectional view of the blade tip of the fan blade of Embodiment 4 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0034] Figure 14 The front view of the fan blade of the negative pressure fan with high impedance and reduced wind loss provided by this utility model is shown in Embodiment 5.

[0035] Figure 15 A partial sectional view of the blade tip of the fan blade of Embodiment 5 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0036] Figure 16 The front view of the fan blade of the negative pressure fan with high impedance and reduced wind loss provided by this utility model is shown in Embodiment Six.

[0037] Figure 17 A partial cross-sectional view of the blade tip of a negative pressure fan with high impedance and reduced wind loss provided by this utility model, in embodiment six.

[0038] Figure 18 The front view of the fan blade of the negative pressure fan with high impedance and reduced wind loss provided by this utility model is shown in Embodiment Seven.

[0039] Figure 19 A partial sectional view of the blade tip of the fan blade of Embodiment 7 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0040] Figure 20 A cross-sectional view of Embodiment 2 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0041] Figure 21 The front view of Embodiment 2 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0042] Figure 22 This is a cross-sectional view of Embodiment 3 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0043] Figure 23 The front view of Embodiment 3 of the high-impedance negative pressure fan for reducing wind loss provided by this utility model.

[0044] Figure 24 A cross-sectional view of Embodiment 4 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0045] Figure 25 The front view of Embodiment 4 of the high-impedance negative pressure fan that reduces wind loss provided by this utility model.

[0046] Figure 26 A cross-sectional view of Embodiment 5 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0047] Figure 27 The front view of Embodiment 5 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0048] Figure 28 The front view of Embodiment Six of the High Impedance Negative Pressure Fan for Reducing Wind Loss provided by this utility model.

[0049] Figure 29 A partial cross-sectional view of the air volume loss prevention disc connection structure of Embodiment 6 of the negative pressure fan for reducing wind loss with high impedance provided by this utility model.

[0050] Figure 30 A perspective view of the airflow loss prevention disc in Embodiment Six of the high-impedance negative pressure fan for reducing wind loss provided by this utility model.

[0051] Figure 31 The front view of Embodiment 7 of the high-impedance negative pressure fan for reducing wind loss provided by this utility model.

[0052] Figure 32 A partial cross-sectional view of the air volume loss prevention disc connection structure of Embodiment 7 of the high impedance negative pressure fan for reducing wind loss provided by this utility model.

[0053] Figure 33 A perspective view of the air volume loss prevention disc in Embodiment 7 of the high-impedance negative pressure fan for reducing wind loss provided by this utility model.

[0054] Figure 34 The front view of Embodiment 8 of the high-impedance negative pressure fan for reducing wind loss provided by this utility model.

[0055] Figure 35 A partial cross-sectional view of the air volume loss prevention disc connection structure of Embodiment 8 of the negative pressure fan for reducing wind loss with high impedance provided by this utility model.

[0056] Figure 36 A perspective view of the air volume loss prevention disc in Embodiment 8 of the high-impedance negative pressure fan for reducing wind loss provided by this utility model.

[0057] Figure 37 A cross-sectional view of Embodiment Nine of the High Impedance Negative Pressure Fan for Reducing Wind Loss Provided by this Utility Model.

[0058] Figure 38 The front view of Embodiment Nine of the High Impedance Negative Pressure Fan for Reducing Wind Loss provided by this utility model.

[0059] Figure 39 A perspective view of Embodiment Nine of the High-Impedance Negative Pressure Fan for Reducing Wind Loss Provided by this Utility Model.

[0060] Figure 40 This is a cross-sectional view of Embodiment 10 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0061] Figure 41 The front view of Embodiment 10 of the high-impedance negative pressure fan that reduces wind loss provided by this utility model.

[0062] Figure 42 A perspective view of Embodiment 10 of the negative pressure fan with high impedance and reduced wind loss provided by this utility model.

[0063] Explanation of reference numerals in the attached figures:

[0064] 1-Fan housing, 2-Motor bracket, 3-Motor, 4-Fixed flange, 5-Impeller, 6-Air volume loss prevention disc, 7-Dynamic sealing structure, 8-Bracket, 9-Dust cover;

[0065] 31-Shaft;

[0066] 51 - Fan blade, 52 - Wheel hub;

[0067] 71-Blade sealing ring, 72-Flexible sealing ring. Detailed Implementation

[0068] Various exemplary embodiments of the present invention are now described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features and implementations of the present invention.

[0069] Various improvements and variations can be made to the specific embodiments described in this utility model without departing from the scope or spirit of this utility model, which will be obvious to those skilled in the art. Other embodiments derived from this utility model description will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0070] This invention provides a negative pressure fan with high impedance to reduce wind loss, such as... Figure 1-4 The diagram shows the structure of the negative pressure fan. In a specific embodiment, the negative pressure fan includes: a fan housing 1, and a motor bracket 2 for fixing a motor 3 is fixedly installed on the inner wall of the fan housing 1.

[0071] The motor 3's rotating shaft 31 is fixedly connected to the impeller 5 via a fixing flange 4. An airflow loss prevention disc 6 is coaxially mounted at the shaft center of the impeller 5, and the maximum radius of the airflow loss prevention disc 6 is greater than the radius at the blade root of the impeller 5. In this embodiment, the airflow loss prevention disc 6 is integrally formed with the impeller 5. Furthermore, the axial cross-section of the airflow loss prevention disc 6 is trapezoidal, and the airflow loss prevention disc 6 extends outwards axially and radially from its connection point with the impeller 5. That is, the end of the airflow loss prevention disc 6 with a smaller diameter is integrally connected to the impeller 5, while the end with a larger diameter faces the air outlet side.

[0072] In a specific embodiment of this utility model, the impeller 5 includes multiple independent fan blades 51, which are uniformly fixed around the circumference of the fixed flange 4. In this embodiment, the multiple fan blades 51 can be manufactured using a single mold. The manufacturing precision and offset angle between the fan blades are similar, and when combined into a complete impeller, its center of gravity can approach the axis, resulting in less vibration caused by the offset. Furthermore, the individual fan blades have lower internal stress, resulting in less deformation compared to the overall fan blades during rotation, leading to higher air delivery efficiency at high speeds. In addition, the molds for the individual fan blades are smaller, resulting in lower manufacturing costs, and the fan blades can be replaced and maintained individually later, resulting in low usage and maintenance costs.

[0073] A hub 52 is provided at the root of the fan blade 51. The hubs 52 of multiple fan blades 51 are connected and fixed on the fixed flange 4, and the multiple hubs 52 can be connected to form a circular hub.

[0074] In this embodiment, the airflow loss prevention disc 6 is integrally connected to the fan blade 51. For example... Figure 1 As shown, the connection end of the air volume loss stop plate 6 is integrated with the blade root of the fan blade 551.

[0075] In a specific embodiment of this utility model, an annular dust cover is fixedly provided on the inner wall of the air volume stop plate 6 to reduce the wind resistance of the fixed structure on the inner wall of the air volume stop plate 6 and prevent dust accumulation.

[0076] In this embodiment of the invention, a dynamic sealing structure 7 is provided between the fan blade 51 and the inner wall of the fan housing 1. For example... Figure 1 and 4 As shown, the dynamic sealing structure 7 consists of a blade sealing ring 71 disposed at the tip of the fan blade 51 and a flexible sealing ring 72 disposed on the inner wall of the fan housing 1. The blade sealing ring 71 can move and contact with the flexible sealing ring 72.

[0077] like Figure 6 and 7 As shown, the blade sealing ring 71 has a consistent front and rear height. In this embodiment, the outer side of the flexible sealing ring 72 has a felt structure. When the impeller rotates, the blade sealing ring 71 can extend into the felt of the flexible sealing ring 72, achieving a dynamic sealing effect while reducing friction caused by contact. Furthermore, the blade sealing ring 71 can be horizontally embedded in the felt of the sealing ring, remaining parallel to the felt, further reducing friction. Compared to an inclined blade sealing ring 71 contacting the felt, this reduces friction, resistance, and the contact area.

[0078] like Figure 5 The diagram shown is a structural diagram of the impeller of the high-impedance negative pressure fan with reduced wind loss provided by this utility model, in embodiment two. This embodiment is similar to... Figure 4 The difference in the illustrated embodiment is that the blade width is narrower in this embodiment.

[0079] like Figure 8 and 9 This is a structural diagram of the fan blades in Embodiment 2 of the high-impedance, low-wind-loss negative pressure fan provided by this utility model. This embodiment is similar to... Figure 6 The difference in the illustrated embodiment is that, in this embodiment, the blade sealing ring 71 extends upward to a certain height to form an extended sealing ring, and an annular sealing portion extends outward along the radial direction of the impeller from the top of the extended sealing ring. The upward extension height of the blade sealing ring 71 is greater than... Figure 6 The height to which the blade sealing ring 71 extends upward in the embodiment shown.

[0080] like Figure 10 and 11 This is a structural diagram of the fan blade of a negative pressure fan with high impedance and reduced wind loss provided by this utility model, in embodiment three. This embodiment is similar to... Figure 8 The difference in the illustrated embodiment is that, in this embodiment, the blade sealing ring 71 extends downwards, and... Figure 8 In the illustrated embodiment, the blade sealing ring 71 extends in opposite directions.

[0081] like Figure 12 and 13 This is a structural diagram of the fan blade of the high-impedance negative pressure fan with reduced wind loss provided by this utility model, in embodiment four. This embodiment is similar to... Figure 8 The difference in the illustrated embodiment is that, in this embodiment, the blade sealing ring 71 extends upward to a certain height to form an extended sealing ring, and an annular sealing portion extends outward along the radial direction of the impeller in the middle of the extended sealing ring.

[0082] like Figure 14 and 15This is a structural diagram of the fan blade of the high-impedance, low-wind-loss negative pressure fan provided by this utility model, in embodiment five. This embodiment is similar to... Figure 10 The difference in the illustrated embodiment is that, in this embodiment, the blade sealing ring 71 extends downward a shorter distance.

[0083] like Figure 16 and 17 This is a structural diagram of the fan blade of a negative pressure fan with high impedance and reduced wind loss provided by this utility model, in embodiment six. This embodiment is similar to... Figure 12 The difference in the illustrated embodiment is that, in this embodiment, the blade sealing ring 71 extends upward to a certain height to form an extended sealing ring, and an annular sealing portion extends outward from the top, middle and bottom of the extended sealing ring along the radial direction of the impeller.

[0084] like Figure 18 and 19 This is a structural diagram of the fan blade of the high-impedance, low-wind-loss negative pressure fan provided by this utility model, in embodiment seven. This embodiment is similar to... Figure 12 The difference in the illustrated embodiment is that, in this embodiment, the blade sealing ring 71 extends upward to a certain height to form an extended sealing ring, and an annular sealing portion extends outward from the top and bottom of the extended sealing ring along the radial direction of the impeller.

[0085] like Figure 20 and Figure 21 The diagram shown is a structural schematic of Embodiment 2 of the high-impedance negative pressure fan for reducing wind loss provided by this utility model. This embodiment is similar to... Figure 1 The difference in the embodiment shown is that, in this embodiment, the connection between the airflow loss prevention plate 6 and the blade root of the fan blade 51 does not have an annular groove, and the inner sidewall of the airflow loss prevention plate 6 is not provided with a dust cover 9.

[0086] In addition, a dynamic sealing structure 7 is provided between the fan blade 51 and the inner wall of the fan housing 1. The dynamic sealing structure 7 consists of the tip of the fan blade 51 and a flexible sealing ring 72 disposed on the inner wall of the fan housing 1, and the tip of the fan blade 51 can move and contact the flexible sealing ring 72. In this embodiment, the width of the fan blade 51 is reduced.

[0087] like Figure 22 and Figure 23 The diagram shown is a structural schematic of Embodiment 3 of the high-impedance negative pressure fan for reducing wind loss provided by this utility model. This embodiment is similar to... Figure 20 The difference in the illustrated embodiment is that, in this embodiment, the airflow stop plate 6 is not integrated with the fan blade 51, and the airflow stop plate 6 is fixed to the outer wall of the hub 52 by screws.

[0088] like Figure 24 and Figure 25The diagram shown is a structural schematic of Embodiment 4 of the high-impedance negative pressure fan for reducing wind loss provided by this utility model. This embodiment is similar to... Figure 22 The difference in the illustrated embodiment is that, in this embodiment, the fixed end of the airflow loss prevention disc 6 is located on the side of the hub 52 near the rotating shaft 31, and the airflow loss prevention disc 6 and the fan blade 51 are fixedly mounted together on the fixed flange 4 by bolts. In addition, the fixed end of the airflow loss prevention disc 6 is in close contact with the fixed flange 4 and the side wall of the hub 52.

[0089] like Figure 26 and Figure 27 The diagram shown is a structural schematic of Embodiment 5 of the high-impedance negative pressure fan for reducing wind loss provided by this utility model. This embodiment is similar to... Figure 24 The difference in the illustrated embodiment is that, in this embodiment, the fixed end of the airflow stop plate 6 is located on the side of the hub 52 near the rotating shaft 31, and the airflow stop plate 6 and the fan blade 51 are fixedly mounted together on the fixed flange 4 by bolts. In addition, the fixed end of the airflow stop plate 6 is tightly attached to the fixed flange 4, with a gap between it and the side wall of the hub 52.

[0090] like Figures 28-30 The diagram shown is a structural schematic of Embodiment Six of the High-Impedance, Wind-Loss-Reducing Negative Pressure Fan provided by this utility model. This embodiment is similar to... Figure 26 The difference in the illustrated embodiment is that, in this embodiment, the fan blade 51 is fixed to the fixed flange 4 by a snap-fit ​​method. Multiple fixing plates extend radially inward from the fixing end of the airflow loss prevention disc 6, and these fixing plates are evenly distributed around the circumference of the fixing end. The fixing plates are tightly attached to the surface of the fixed flange 4, and the fixing holes on the fixing plates correspond to the fixing holes on the fixed flange 4. Fixing bolts secure the airflow loss prevention disc 6 to the fixed flange 4 through these fixing holes. In this embodiment, the airflow loss prevention disc 6 is fixedly positioned on the side of the fixed flange 4 facing the air outlet.

[0091] In addition, the leading and trailing edges of the fan blade 51 extend in a straight line from the root to the tip.

[0092] like Figures 31-33 The diagram shown is a structural schematic of Embodiment 7 of the high-impedance negative pressure fan for reducing wind loss provided by this utility model. This embodiment is similar to... Figure 28 The difference in the illustrated embodiment is that, in this embodiment, the fixed end of the airflow loss prevention disc 6 has multiple fixing plates extending radially inward, and the fixing plates are evenly distributed around the circumference of the fixed end. A fixing ring is connected to the end of each fixing plate. Each fixing plate has a fixing hole corresponding to a fixing hole on the fixing flange 4, and the fixing ring also has multiple fixing holes evenly distributed, corresponding to fixing holes on the fixing flange 4. Fixing bolts secure the airflow loss prevention disc 6 to the fixing flange 4 through these fixing holes.

[0093] like Figures 34-36The diagram shown is a structural schematic of Embodiment 8 of the high-impedance negative pressure fan for reducing wind loss provided by this utility model. This embodiment is similar to... Figure 28 The difference in the illustrated embodiment is that, in this embodiment, the fixed end of the airflow stop plate 6 has multiple fixing plates extending radially inward, and the fixing plates are evenly distributed around the circumference of the fixed end. The fixing plates are not tightly attached to the surface of the fixed flange 4, but have fixing grooves. The fixing grooves are provided with fixing holes corresponding to the fixed flange 4. Bolts pass through the fixing flange and the fixing holes on the fixing plates in sequence, and then the bolts are fixed by two nuts on both sides of the fixing groove.

[0094] This invention provides a negative pressure fan with high impedance to reduce wind loss, such as... Figures 37-39 The diagram shown is a structural schematic of embodiment nine of the negative pressure fan. In a specific embodiment, the negative pressure fan includes: a fan housing 1, and a motor bracket 2 for fixing a motor 3 is fixedly installed on the inner wall of the fan housing 1.

[0095] The impeller 5 is fixedly connected to the rotating shaft 31 of the motor 3 via the fixed flange 4.

[0096] A bracket 8 is fixedly connected to the inner wall of the air outlet of the fan housing 1. An airflow loss prevention disc 6 is fixedly installed on the bracket 8. The airflow loss prevention disc 6 is coaxially arranged with the impeller 5 but does not contact the impeller 5. The maximum radius of the airflow loss prevention disc 6 is larger than the radius at the blade root of the impeller 5. This airflow loss prevention disc 6 can reduce the backflow of airflow from the hub 52 of the impeller 5 or the blade root of the fan blade 51, thereby reducing airflow loss.

[0097] In a specific embodiment of this utility model, the impeller 5 includes multiple independent fan blades 51, which are uniformly fixed around the circumference of the fixed flange 4. In this embodiment, the multiple fan blades 51 can be manufactured using a single mold. The manufacturing precision and offset angle between the fan blades are similar, and when combined into a complete impeller, its center of gravity can approach the axis, resulting in less vibration caused by the offset. Furthermore, the individual fan blades have lower internal stress, resulting in less deformation compared to the overall fan blades during rotation, leading to higher air delivery efficiency at high speeds. In addition, the molds for the individual fan blades are smaller, resulting in lower manufacturing costs, and the fan blades can be replaced and maintained individually later, resulting in low usage and maintenance costs.

[0098] A hub 52 is provided at the root of the fan blade 51. The hubs 52 of multiple fan blades 51 are connected and fixed on the fixed flange 4, and the multiple hubs 52 can be connected to form a circular hub.

[0099] In this embodiment of the invention, the fan blade 51 and the inner wall of the fan housing 1 have a dynamic sealing structure 7.

[0100] The dynamic sealing structure 7 consists of the blade tip of the fan blade 51 and a flexible sealing ring 72 disposed on the inner wall of the fan housing 1. The blade tip of the fan blade 51 can move and contact the flexible sealing ring 72. In this embodiment, the outer side of the flexible sealing ring 72 has a fluffy structure. When the impeller 5 rotates, the blade tip of the fan blade 51 can extend into the fluff of the flexible sealing ring 72, which can achieve a dynamic sealing effect while reducing friction caused by contact.

[0101] like Figures 40-42 The diagram shown is a structural schematic of Embodiment 10 of the high-impedance negative pressure fan for reducing wind loss provided by this utility model. This embodiment is similar to... Figure 26 The difference in the illustrated embodiment is that, in this embodiment, there is no dynamic sealing structure between the fan blade 51 and the inner wall of the fan housing 1. Furthermore, the fan blade 51 is fixed to the fixed flange 4 by a snap-fit ​​connection, and the leading and trailing edges of the fan blade 51 extend in a straight line from the blade root to the blade tip.

[0102] The above description is merely an illustrative embodiment of this utility model. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of this utility model shall fall within the scope of protection of this utility model.

Claims

1. A negative pressure fan with high impedance to reduce wind loss, characterized in that, The negative pressure fan includes: a fan housing (1), and a motor bracket (2) for fixing a motor (3) is fixedly installed on the inner wall of the fan housing (1); The rotating shaft (31) of the motor (3) is fixedly connected to the impeller (5) through the fixed flange (4). A flow rate stop plate (6) is coaxially arranged at the shaft center of the impeller (5). The maximum radius of the flow rate stop plate (6) is greater than the radius at the blade root of the impeller (5).

2. The negative pressure fan with high impedance and reduced wind loss according to claim 1, characterized in that, The air volume stop plate (6) has a trapezoidal axial section, and the air volume stop plate (6) extends outward in both the axial and radial directions from the connection point with the impeller (5).

3. The high-impedance negative pressure fan for reducing wind loss according to claim 1 or 2, characterized in that, The impeller (5) includes multiple independent blades (51), and the multiple blades (51) are evenly fixed around the circumference of the fixed flange (4); A hub (52) is provided at the root of the fan blade (51), and the hubs (52) of multiple fan blades (51) are connected and fixed on the fixed flange (4).

4. The high-impedance negative pressure fan for reducing wind loss according to claim 3, characterized in that, The air volume stop plate (6) is integrated with the fan blade (51).

5. The negative pressure fan with high impedance and reduced wind loss according to claim 3, characterized in that, The air volume stop plate (6) is fixedly connected to the hub (52) of the fan blade (51) or the fixed flange (4) by a fastener.

6. The high-impedance negative pressure fan for reducing wind loss according to claim 3, characterized in that, The fan blade (51) has a dynamic sealing structure (7) between it and the inner wall of the fan housing (1); The dynamic sealing structure (7) consists of a blade sealing ring (71) disposed at the tip of the fan blade (51) and a flexible sealing ring (72) disposed on the inner wall of the fan housing (1). The blade sealing ring (71) can move and contact with the flexible sealing ring (72).

7. The high-impedance negative pressure fan for reducing wind loss according to claim 3, characterized in that, The fan blade (51) has a dynamic sealing structure (7) between it and the inner wall of the fan housing (1); The dynamic sealing structure (7) consists of the tip of the fan blade (51) and a flexible sealing ring (72) disposed on the inner wall of the fan housing (1). The tip of the fan blade (51) can move and contact with the flexible sealing ring (72).

8. A negative pressure fan with high impedance to reduce wind loss, characterized in that, The negative pressure fan includes: a fan housing (1), and a motor bracket (2) for fixing a motor (3) is fixedly installed on the inner wall of the fan housing (1); The motor (3) shaft (31) is fixedly connected to the impeller (5) via a fixed flange (4); A bracket (8) is fixedly connected to the inner wall of the air outlet of the fan housing (1). An air volume stop plate (6) is fixedly installed on the bracket (8). The air volume stop plate (6) is coaxially arranged with the impeller (5) and does not contact the impeller (5). The maximum radius of the air volume stop plate (6) is greater than the radius at the blade root of the impeller (5).

9. The negative pressure fan with high impedance and reduced wind loss according to claim 8, characterized in that, The impeller (5) includes multiple independent blades (51), and the multiple blades (51) are evenly fixed around the circumference of the fixed flange (4); A hub (52) is provided at the root of the fan blade (51), and the hubs (52) of multiple fan blades (51) are connected and fixed on the fixed flange (4).

10. The negative pressure fan with high impedance and reduced wind loss according to claim 9, characterized in that, The fan blade (51) has a dynamic sealing structure (7) between it and the inner wall of the fan housing (1); The dynamic sealing structure (7) consists of the tip of the fan blade (51) and a flexible sealing ring (72) disposed on the inner wall of the fan housing (1). The tip of the fan blade (51) can move and contact with the flexible sealing ring (72).

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