Oven

Abstract

The application provides an oven, in which a fan double air inlet can simultaneously undertake pressure relief and heat dissipation functions, a first air inlet inhales hot air in an interval space, and high-pressure gas inhaled by a second air inlet is discharged through an exhaust air duct after being combined with the hot air. A through channel is provided in an axial direction of an impeller assembly, the through channel communicates a space where a first impeller is located with a space where a second impeller is located, and because the air pressure generated by the first impeller is greater than that of the second impeller, a pressure difference from the first impeller to the second impeller is formed in the through channel. The pressure difference can inhibit air flow from entering the fan from the second air inlet, reduce the suction force of the second impeller on the pressure relief hole, and thus avoid excessive air flow carrying heat and being discharged due to the excessive suction force, so that heat loss can be effectively relieved under the condition of ensuring heat dissipation, and the energy efficiency of the oven is improved.

Description

Technical Field

[0001] This application belongs to the field of baking equipment, and more specifically, relates to an oven. Background Technology

[0002] An oven is a kitchen appliance that uses internal heating elements to generate high temperatures to bake, roast, or heat food. It is widely used in everyday home cooking and professional baking settings.

[0003] During use, ovens need to dissipate heat and release internal pressure. This process releases some of the oven's heat, affecting its energy efficiency and resulting in lower energy efficiency. Summary of the Invention

[0004] The purpose of this application is to provide an oven that solves the technical problem of low energy efficiency caused by oven depressurization in the prior art.

[0005] To achieve the above objectives, the technical solution adopted in this application is: to provide an oven, the oven comprising:

[0006] The outer casing; a heat dissipation duct is provided inside the outer casing;

[0007] Inner cavity; the inner cavity is located within the outer shell, and there is a space between the outer shell and the inner cavity for mounting devices. The inner cavity is provided with a pressure relief hole.

[0008] The fan includes a first air inlet, a second air inlet, and an air outlet. The first air inlet is connected to the partition space, and the second air inlet is connected to the pressure relief hole.

[0009] Exhaust duct; the exhaust duct is connected to the air outlet;

[0010] The fan also includes an impeller assembly, which includes a first impeller and a second impeller, which are coaxially arranged.

[0011] The first air inlet and the second air inlet are respectively located at both ends of the fan axis. The first air inlet is opposite to the first impeller so that the airflow is driven by the first impeller to enter the fan from the first air inlet. The second air inlet is opposite to the second impeller so that the airflow is driven by the second impeller to enter the fan from the second air inlet. The air outlet is located on the radial side of the fan so that the airflow can be discharged from the fan.

[0012] The impeller assembly has an axially arranged through channel that connects the space where the first impeller is located and the space where the second impeller is located. The wind pressure generated by the first impeller is greater than the wind pressure generated by the second impeller, so as to form a pressure difference from the first impeller to the second impeller in the through channel.

[0013] Optionally, the first impeller includes a plurality of first blades spaced apart along the circumferential direction, and the second impeller includes a plurality of second blades spaced apart along the circumferential direction; the number of first blades and second blades is equal, and each first blade is connected to a corresponding second blade to form an integral blade, so that the first blade and the second impeller form an integral blade, and the interval between adjacent integral blades forms a through channel.

[0014] Optionally, the impeller assembly also includes a support, to which multiple integral blades are connected.

[0015] Optionally, the support includes a support ring, and the support ring and an integral blade are coaxially connected. The integral blade extends from the radially inner side of the support ring to the radially outer side of the support ring. Through channels are formed between adjacent integral blades on the radially inner side and the radially outer side of the support ring, respectively.

[0016] Alternatively, the support includes a support disk, the support disk and an integral blade are coaxially connected, the integral blade extends to the radially outer side of the support disk; on the radially outer side of the support disk, a through channel is formed between adjacent integral blades.

[0017] Optionally, the cross-section of the support ring in the axial direction is elliptical, and the major axis of the cross-section is perpendicular to the axial direction.

[0018] Optionally, the inner and outer diameters of the support ring satisfy: (Q1-Q2) / 10 < Q3-Q4, and / or, Q3-Q4 < (Q1-Q2) / 2; where Q1 represents the outer diameter of the integral blade, Q2 represents the inner diameter of the integral blade, Q3 represents the outer diameter of the support ring, and Q4 represents the inner diameter of the support ring.

[0019] Optionally, the axial height of the first impeller is greater than the axial height of the second impeller.

[0020] Optionally, the axial height H1 of the first impeller and the axial height H2 of the second impeller satisfy: 1 / 10≤H2 / H1≤1 / 4.

[0021] Optionally, the oven further includes a first partition and a second partition disposed between the outer shell and the inner cavity, with the first partition located on the side of the second partition closer to the outer shell;

[0022] A fan cavity and an exhaust duct are formed between the first and second partitions. An air outlet is formed on the side of the fan cavity and is connected to the exhaust duct through the air outlet.

[0023] The impeller assembly is disposed within the fan cavity, with the first impeller facing the first partition and the first air inlet disposed on the first partition at a position opposite to the first impeller; the second impeller faces the second partition and the second air inlet is disposed on the second partition at a position opposite to the second impeller.

[0024] Optionally, a connecting channel is provided between the second air inlet and the pressure relief hole, and the cross-sectional dimensions of the connecting channel gradually increase from the pressure relief hole to the second air inlet.

[0025] The beneficial effects of the oven provided in this application are as follows: Compared with the prior art, the oven in this application embodiment has dual air inlets for the fan, which can simultaneously perform pressure relief and heat dissipation functions. The first air inlet draws in hot airflow from the space, which merges with the high-pressure gas drawn in from the second air inlet and is then discharged through the exhaust duct. The impeller assembly has a through channel along the axial direction, which connects the spaces where the first impeller and the second impeller are located. Because the wind pressure generated by the first impeller is greater than that of the second impeller, a pressure difference is formed in the through channel from the first impeller to the second impeller. This pressure difference can inhibit airflow from entering the fan from the second air inlet, reducing the suction force of the second impeller on the pressure relief hole. This avoids excessive suction force causing excessive gas to carry heat out, thus effectively dissipating the heat from pressure relief while ensuring heat dissipation, thereby improving the energy efficiency of the oven. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the appearance of the oven in the embodiments of this application;

[0028] Figure 2 This is a schematic diagram of the interior of the oven in an embodiment of this application;

[0029] Figure 3 This is a schematic diagram of the fan arrangement in the oven in this embodiment of the application;

[0030] Figure 4 A cross-sectional schematic diagram showing the location of the fan in the oven in this embodiment of the application;

[0031] Figure 5 This is a schematic diagram of an impeller assembly in one embodiment of this application;

[0032] Figure 6 for Figure 5 A top-view schematic diagram of the impeller assembly in the illustrated embodiment;

[0033] Figure 7 This is a schematic diagram of an impeller assembly in another embodiment of this application;

[0034] Figure 8 for Figure 7 A top-view schematic diagram of the impeller assembly in the illustrated embodiment;

[0035] Figure 9 for Figure 5 A partial cross-sectional schematic diagram of the impeller assembly in the illustrated embodiment;

[0036] Figure 10 This is a schematic diagram of an impeller assembly in another embodiment of this application;

[0037] Figure 11 for Figure 10 A side view of the impeller assembly in the illustrated embodiment;

[0038] Figure 12 This is an exploded view of the partition structure in an embodiment of this application;

[0039] Figure 13 This is a schematic diagram of the pressure relief hole and the pressure relief channel of the second air duct in the embodiments of this application;

[0040] Figure 14 This is an independent schematic diagram of the pressure relief channel in the embodiments of this application.

[0041] The following are the labeling elements in the figure:

[0042] Oven 100; outer shell 1; inner cavity 2; partition space; pressure relief hole 21; fan 3; first air inlet 31; second air inlet 32; air outlet 33; impeller assembly 34; integrated blade 340; first impeller 341; first blade 3411; second impeller 342; second blade 3421; support ring 344; support plate 345; through channel 346; drive component 35; fan cavity 36; exhaust duct 4; first partition 51; second partition 52; pressure relief channel 53; connecting buckle 531. Detailed Implementation

[0043] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0044] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0045] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and 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. Therefore, they should not be construed as limitations on this application.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0047] As a common household appliance, ovens typically consist of several main components, including the outer shell, heating element, inner cavity, temperature control system, door and sealing structure, and control panel. The outer shell serves as the oven's external support structure, usually made of cold-rolled steel or stainless steel, with a powder-coated or brushed finish. This protects internal components from impact damage and insulates against the high temperatures transmitted through the cavity, preventing accidental burns. The heating element is the core heating component, commonly consisting of heating tubes and heating wires. Heating tubes can be quartz or stainless steel, and are usually arranged in two sets, one at the top and one at the bottom. Some ovens also have a rear heating element responsible for generating the high temperatures required for baking. The inner cavity is a sealed space made of high-temperature resistant metal, where food is placed for baking. The inner walls are often treated with non-stick or easy-to-clean materials for convenient daily cleaning. The temperature control system includes a temperature sensor and a thermostat. The temperature sensor detects the cavity temperature, while the thermostat adjusts the heating element's operation based on the set temperature to maintain a stable cavity temperature. The door is often made of double-layered high-temperature resistant glass for easy observation of the baking process, and sealing strips around the door edges reduce heat and gas leakage. The control panel is the main part of the human-computer interaction, where parameters such as temperature, time, and baking mode can be set via knobs, buttons, or touch screen.

[0048] When the oven is working, the user sets the target temperature and baking time via the control panel. Upon receiving the command, the temperature control system activates the heating element. The heating element generates heat, which is transferred to the interior cavity through thermal radiation and convection, gradually raising the cavity temperature. A temperature sensor monitors the cavity temperature in real time. When the set temperature is reached, the thermostat sends a signal to cut off the power to the heating element, stopping heating. When the cavity temperature drops below the set value, the thermostat restarts the heating element, and this cycle repeats to ensure the temperature remains within the set range throughout the baking process. During baking, the moisture in the food vaporizes, causing changes in the cavity pressure. Structures such as pressure relief vents help maintain pressure balance. Once the set baking time is complete, the heating element automatically shuts off.

[0049] Currently, most ovens employ a passive pressure relief design, typically relying on a tiny gap between the oven door and the cavity, or a simple pressure relief vent on the top of the oven. Gas is naturally guided out by the pressure difference between the inside and outside. The dimensions of these gaps and vents are usually fixed, preset for typical usage scenarios at the factory, and cannot be adjusted according to actual baking needs. Gaps that are too wide will cause heat loss and affect temperature control accuracy, while gaps that are too narrow will limit exhaust capacity. Top pressure relief vents are often single-diameter round holes or grid structures, relying solely on natural airflow for exhaust. This design may handle slow-accumulating, slight pressure in normal baking scenarios, but it will immediately cause problems when faced with a sudden increase in pressure.

[0050] For example, when baking ingredients rich in moisture, such as a whole roasted chicken, potatoes with skin, or fresh fruit and vegetable tarts, the high temperature causes a large amount of moisture in the ingredients to vaporize in a short period of time, forming a steam flow. This sudden steam burst can often increase the pressure inside the oven several times over in a short time. Passive pressure relief methods lack an active pressure sensing mechanism, and relying solely on natural permeation for exhaust is extremely inefficient, unable to quickly balance the pressure difference between the inside and outside of the oven. This delay in pressure release can not only affect the rising effect and texture of baked goods, but also pose safety hazards due to the continuous accumulation of pressure. At best, the oven door may be forced open by the pressure, causing hot gas and liquid to splash and burn the user. At worst, it may cause deformation of the oven's sealing structure, affecting the oven's lifespan, and in extreme cases, there is even a risk of the cavity bursting.

[0051] Furthermore, passive depressurization has significant limitations in controllability, failing to proactively control the depressurization state based on ingredient characteristics and baking stage. In the early stages of baking, when maintaining a certain level of humidity is crucial, such as during the rising phase of a cake, the fixed depressurization structure continuously releases moisture, leading to insufficient humidity and affecting the cake's fluffiness. Conversely, in the final stages, when rapid dehumidification is needed, such as during the crisping and shaping of cookies, the limited degassing efficiency cannot remove excess moisture in time, resulting in softer cookies that are less durable. This indiscriminate passive degassing mode cannot achieve precise depressurization tailored to the baking curves of different ingredients, limiting the potential for home users to improve baking quality.

[0052] To address the above problems, this application provides an oven 100, please refer to [link / reference needed]. Figure 1 , Figure 2 , Figure 3 and Figure 4 The oven 100 in the embodiments of this application includes:

[0053] Casing 1; a heat dissipation duct 20 is provided inside the casing 1;

[0054] Inner cavity 2; the inner cavity 2 is disposed inside the outer shell 1, and the inner cavity 2 is provided with a pressure relief hole 21;

[0055] Fan 3; Fan 3 includes a first air inlet 31, a second air inlet 32 ​​and an air outlet 33, the first air inlet 31 is connected to the partition space, and the second air inlet 32 ​​is connected to the pressure relief hole 21;

[0056] Exhaust duct 4; Exhaust duct 4 is connected to air outlet 33.

[0057] In this embodiment, the outer shell 1 serves as the outer structure of the oven 100, providing installation support and safety protection for the internal components. The inner cavity 2 is located inside the outer shell 1, forming a closed space for baking food. A partition space is created between the two, used to install power supply systems, temperature control systems, and other devices. The side of the inner cavity 2 facing the outer shell 1 is typically lined with heat-insulating material to reduce heat entering the closed space. A pressure relief hole 21 is specifically provided on the inner cavity 2 to balance the pressure inside. The fan 3 is the power component for airflow control, equipped with a first air inlet 31, a second air inlet 32, and an air outlet 33; that is, the fan 3 is a dual-inlet fan 3. The second air inlet 32 ​​directly connects to the pressure relief hole 21 of the inner cavity 2, the first air inlet 31 connects to the partition space between the outer shell 1 and the inner cavity 2, and the air outlet 33 points solely to the exhaust duct 4. The fan 3 can be located at the top, side, or bottom of the oven 100, such as... Figure 3In the illustrated embodiment, the fan 3 is located at the top of the oven 100, facilitating connection to the pressure relief hole 21 at the top of the inner cavity 2. The heat dissipation duct 20 is a channel for airflow to dissipate heat inside the outer casing. The heat dissipation duct 20 typically passes through the main heat-generating components. For example, in some embodiments, there is a space between the outer casing 1 and the inner cavity 2 for mounting devices, and this space forms the heat dissipation duct 20.

[0058] When the oven 100 starts baking, the food in the inner cavity 2 is heated, and the moisture quickly vaporizes, generating a large amount of steam, causing the internal pressure to gradually increase. At this time, the fan 3, connected to the pressure relief hole 21 of the inner cavity 2, starts operating, and its second air inlet 32 ​​forms a negative pressure environment under the power of the fan 3. This negative pressure actively draws the high-pressure gas accumulated in the inner cavity 2 into the fan 3 through the pressure relief hole 21. Subsequently, the gas enters the exhaust duct 4 through the air outlet 33 of the fan 3 and is finally directionally discharged outside the oven 100. Throughout the process, the pressure relief hole 21 serves as the outlet for pressure discharge, the fan 3 provides the power for active extraction, and the exhaust duct 4 serves as the channel for airflow guidance; the three form a complete linkage mechanism. Instead of relying on the natural pressure difference between the inside and outside, the pressure is discharged through the active drive of the fan 3, achieving active regulation of the pressure in the inner cavity 2.

[0059] Traditional ovens 100 rely solely on fixed door gaps or pressure relief vents 21 for exhaust, with the exhaust speed entirely determined by pressure differences. In cases of sudden steam surges, pressure release is often delayed. This new structure, consisting of pressure relief vents 21, dual-inlet fans 3, and exhaust ducts 4, can respond to pressure changes in real time via the power of the fans 3. Even with a large amount of steam generated in a short period, it can quickly extract the gas, preventing excessive pressure. Active pressure extraction effectively prevents excessive pressure in the cavity 2 from forcing open the oven door, thus preventing hot gas and liquid from splashing and scalding the user. It also reduces the impact of pressure on the cavity's sealing structure, lowering the risk of equipment deformation. Furthermore, stable pressure in the cavity 2 creates a balanced cooking environment for the food, reducing interference from pressure fluctuations on the expansion, shaping, and moisture distribution of the food. This allows the food to maintain a stable state during baking, significantly improving the quality of the finished product.

[0060] When the oven 100 is running, the components installed in the partition space will generate redundant heat, and some heat will also escape from the inner cavity into the partition space. If this heat is not dissipated in time, it can easily affect the performance of the components. In this embodiment, the first air inlet 31 of the fan 3 is connected to the partition space. When the fan 3 starts to draw high-pressure gas from the inner cavity 2, the first air inlet 31 will also generate suction, drawing the hot airflow from the partition space into the fan 3. Subsequently, the hot airflow in the partition space and the high-pressure gas in the inner cavity 2 will merge in the fan 3 and be discharged together through the air outlet 33 into the exhaust duct 4. At the same time, ambient temperature air from outside will naturally replenish the partition space through the gaps in the outer shell 1 or the specially designed air inlet, forming a continuous cycle of hot airflow extraction and ambient temperature air replenishment, achieving efficient heat dissipation of the partition space.

[0061] In this embodiment, the fan 3 simultaneously performs pressure relief and heat dissipation functions through dual air inlets, eliminating the need for an additional cooling fan and independent air duct, thus reducing the number of components. The sharing of an exhaust duct for both types of airflow also allows for a more compact internal layout, reducing manufacturing costs and enabling the miniaturization design of the oven 100. For example... Figure 1 The oven 100 in the text is actually a built-in oven 100, which has high requirements for its size. The compact internal layout can ensure the baking space inside the oven 100 while keeping the external dimensions of the oven 100 controllable.

[0062] Please see Figure 5 and Figure 6 In one embodiment of this application, the fan 3 further includes an impeller assembly 34, which includes a first impeller 341 and a second impeller 342, which are coaxially arranged. A first air inlet 31 and a second air inlet 32 ​​are respectively located at both ends of the fan 3's axial direction. The first air inlet 31 is opposite to the first impeller 341, so that airflow is driven by the first impeller 341 to enter the fan 3 from the first air inlet 31. The second air inlet 32 ​​is opposite to the second impeller 342, so that airflow is driven by the first impeller 341 to enter the fan 3. Airflow is driven by the second impeller 342 to enter the fan 3 through the second air inlet 32; the air outlet 33 is located on the radial side of the fan 3 to allow airflow to exit the fan 3; the impeller assembly 34 has an axially arranged through channel 346 connecting the space where the first impeller 341 is located and the space where the second impeller 342 is located. The air pressure generated by the first impeller 341 is greater than the air pressure generated by the second impeller 342, so as to form a pressure difference from the first impeller 341 to the second impeller 342 within the through channel 346. The first impeller 341 and the second impeller 342 are coaxially mounted on a drive shaft, which is driven by a motor or other drive components 35. Figure 4 In the embodiment shown, the drive component 35 is mounted on the upper part of the first air inlet 31 by a bracket. Without obstructing the air intake of the first air inlet 31, the airflow of the first air inlet 31 can be used to dissipate heat from the drive component 35.

[0063] The core actuating component of the fan 3 is the impeller assembly 34, which includes a first impeller 341 and a second impeller 342, both coaxially arranged via the same drive shaft. In the fan 3 layout, the first air inlet 31 and the second air inlet 32 ​​are located at opposite ends of the fan 3's axial direction, each precisely aligned with its corresponding impeller. The first air inlet 31 faces the first impeller 341, through which airflow is driven to enter the fan 3; the second air inlet 32 ​​faces the second impeller 342, through which airflow is drawn in. The fan 3's exhaust structure is a radially side outlet 33, allowing the two airflows to converge and then exit. In addition, the impeller assembly 34 is provided with a through channel 346 along the axial direction. The through channel 346 connects the space where the first impeller 341 and the second impeller 342 are located. Since the wind pressure generated by the first impeller 341 is greater than that of the second impeller 342, a pressure difference is formed in the through channel 346 from the first impeller 341 to the second impeller 342.

[0064] The pressure difference within the passage 346 forms a pressure barrier pointing from the first impeller 341 side to the second impeller 342 side, directly affecting the airflow intake process at the second air inlet 32. The second impeller 342 already drives the pressure relief airflow at low pressure, and the reverse pressure generated by the pressure difference inhibits the airflow from entering the fan 3 through the second air inlet 32, reducing the suction force of the second impeller 342 on the pressure relief hole 21. This inhibition does not block pressure relief, but rather controls the flow rate of the pressure relief airflow entering the fan 3, preventing excessive gas discharge due to excessive suction.

[0065] The first impeller 341 and the second impeller 342 rotate coaxially at the same speed. The first impeller 341, thanks to its high air pressure characteristics, can still efficiently draw in hot air from the interstitial space, fully ensuring the heat dissipation effect. Simultaneously, the pressure difference suppresses air intake through the second air inlet 32, significantly reducing the additional pressure relief flow that might be introduced due to airflow linkage when the first impeller 341 is operating, while maintaining the same impeller speed. This achieves a balance between undiminished heat dissipation capacity and controllable pressure relief flow.

[0066] After the pressure difference suppresses the pressure relief flow, the total amount of high-temperature gas discharged from the inner cavity 2 through the pressure relief hole 21 and the second air inlet 32 ​​is significantly reduced, preventing excessive high-temperature airflow from carrying away the heat from the inner cavity 2. This allows the heat generated by the heating element of the oven 100 to be more concentrated on baking the food, reducing ineffective heat loss due to pressure relief, reducing the extra power consumption required by the heating element to maintain the inner cavity temperature, and directly improving the energy efficiency of the equipment.

[0067] While ensuring effective heat dissipation, the precise control of pressure differential over the pressure relief flow rate allows fan 3 to achieve dynamic adaptation between heat dissipation and pressure relief without needing to reduce its speed or adjust the flow rate using additional components. This reduces energy waste during functional coordination. Simultaneously, the reduced pressure relief flow rate lowers the proportion of high-temperature air in the converging airflow, alleviating the thermal load on the exhaust duct 4 and further optimizing overall energy utilization efficiency.

[0068] Since the impeller assembly 34 does not have a middle plate, its overall strength is relatively low. Therefore, the impeller assembly 34 in this embodiment is mainly suitable for scenarios with relatively low rotational speed.

[0069] Please see Figure 5 and Figure 6 In some embodiments of this application, the first impeller 341 includes a plurality of first blades 3411 spaced apart along the circumferential direction, and the second impeller 342 includes a plurality of second blades 3421 spaced apart along the circumferential direction; the number of first blades 3411 and second blades 3421 is equal, and each first blade 3411 is connected to the corresponding second blade 3421 to form an integral blade 340, so that the first blades 3411 and the second impeller 342 form an integral blade 340, and the interval between adjacent integral blades 340 forms a through channel 346.

[0070] The first blade 3411 and the second blade 3421 are equal in number and connected to form an integral blade 340, making the impeller assembly 34 a rigid, integrated structure. During coaxial rotation, the integral blade 340 avoids deformation or vibration caused by uneven stress on the separate blades, ensuring complete synchronization of the rotational speed and operating posture of the first blade 3411 and the second blade 3421. This structural stability ensures that the high wind pressure output of the first blade 3411 and the low wind pressure output of the second blade 3421 maintain a stable difference, providing structural support for the pressure difference from the first impeller 341 to the second impeller 342 within the through-channel 346, preventing pressure fluctuations caused by blade deformation.

[0071] The spacing between adjacent integrated blades 340 directly forms the through channel 346. The integrated design of the blades ensures that the length of the through channel 346 is perfectly matched with the axial dimension of the impeller, ensuring that the pressure difference can be evenly applied to the entire channel, forming a stable pressure gradient and enhancing the suppression effect on the air intake of the second air inlet 32.

[0072] The integrated blade 340 enables the first impeller 341 and the second impeller 342 to be driven by the same body, which can more accurately and synchronously respond to the drive shaft power compared to separate blades. When the fan 3 is running, the actions of the first blade 3411 drawing in the cooling airflow and the second blade 3421 drawing in the depressurized airflow are completely synchronized, avoiding the power transmission delay that may occur in a separate structure.

[0073] The integrated blade 340 integrates the first impeller 341, the second impeller 342, and the through channel 346 into a single component. This reduces the assembly steps and component gaps in the impeller assembly 34, lowering the risk of airflow leakage at blade gaps or component joints. It also allows the high wind pressure generated by the first blade 3411 to act more concentratedly on the through channel 346, enhancing the pressure differential suppression effect. Simultaneously, the simplified structure allows for smoother airflow within the channel, reducing energy loss and making the pressure differential's control over the pressure relief flow more efficient.

[0074] In some embodiments of this application, the impeller assembly 34 further includes a support member, to which a plurality of integral blades 340 are connected.

[0075] The support component connects multiple integrated blades 340 into a complete impeller unit, significantly improving the overall rigidity of the blade assembly. When the integrated blades 340 rotate coaxially at high speed, they are subjected to enormous centrifugal forces, especially at the blade tips where deformation is likely to occur. By fixing the support component to each integrated blade 340, a multi-point support and overall force-bearing structure is formed, distributing the centrifugal force borne by a single blade across the entire support component. This prevents the blades from bending or vibrating due to excessive localized stress, ensuring that the blades always maintain their designed geometric shape.

[0076] Normally, such as Figure 6 As shown, if the difference between the outer diameter Q1 and the inner diameter Q2 of the integrated blade 340 is less than 40mm, no support is required; if Q1-Q2≥40mm, a support is required.

[0077] Please see 7 and Figure 8 The support includes a support disk 345, which is coaxially connected with an integral blade 340. The integral blade 340 extends to the radial outer side of the support disk 345. A through channel 346 is formed between adjacent integral blades 340 on the radial outer side of the support disk 345.

[0078] The centrifugal force generated by the high-speed rotation of the integrated blade 340 acts radially outward, with the connection point between the support disk 345 and the blade concentrated in the blade root region. The support disk 345, through its rigid structure, directly transmits the centrifugal force borne by the blade root to the shaft center. This concentrated constraint on the blade root is more precise, effectively resisting shear stress at the blade root and preventing root breakage due to centrifugal force, especially suitable for blade structures that extend only outward. The support disk 345 is coaxially positioned with the blade, ensuring that the centrifugal force of all blades is evenly distributed along the circumference of the support disk 345. The disk-shaped structure of the support disk 345 itself possesses excellent resistance to radial deformation, converting the centrifugal force transmitted by each blade into circumferential stress along the disk's circumference, rather than concentrating it in a localized area.

[0079] The shape of the through-channel 346 on the radially outer side of the support disk 345 is determined by the blade spacing and the edge contour of the support disk 345. The support disk 345, through coaxial positioning, ensures uniform circumferential blade spacing, allowing the through-channel 346 to maintain a regular cross-section along its radially outer side. This results in stable airflow velocity as the airflow passes through the channel, leading to a uniform distribution of aerodynamic impact loads on the blades. The design of the support disk 345 having a channel only on its outer side reduces airflow interference within the support structure, resulting in a more singular aerodynamic load on the blades and less stress fluctuation.

[0080] Please see 5 and Figure 6 In some embodiments of this application, the support member includes a support ring 344, which is coaxially connected with an integral blade 340. The integral blade 340 extends from the radially inner side of the support ring 344 to the radially outer side of the support ring 344. Through channels 346 are formed between adjacent integral blades 340 on the radially inner side and the radially outer side of the support ring 344, respectively.

[0081] The support ring 344 is coaxially connected to the integral blade 340, ensuring a symmetrical distribution of forces on the blade in the circumferential direction. The centrifugal force generated by the high-speed rotation of the integral blade 340 is evenly transmitted to the entire area of ​​the support ring 344 through the connection point, avoiding localized force concentrations that might occur with non-coaxial connections. Simultaneously, the blade extends radially from the inner to the outer side of the support ring 344, with the support ring 344 positioned precisely in the radial center of the blade. This location effectively constrains the radial deformation of the blade, providing stable support to both the inner side near the axis and the outer tip, significantly improving the blade's resistance to bending and vibration.

[0082] The continuous through-channels 346 on both the inner and outer sides of the support ring 344 ensure full connectivity between the spaces containing the first impeller 341 and the second impeller 342, allowing the pressure difference to be uniformly transmitted along the entire length of the channel. Compared to partially connected channels, this fully connected structure avoids local attenuation of the pressure difference during transmission, maintaining a consistent pressure gradient between the inner and outer sides of the support ring 344. Simultaneously, the coaxial support ring 344 ensures that all through-channels 346 have identical flow characteristics, with uniform pressure difference within each channel, preventing local pressure fluctuations due to differences in channel shape and continuously and stably suppressing airflow into the second air inlet 32. The consistent airflow efficiency on the radially inner and outer sides avoids energy consumption caused by local eddies. This allows the first blade 3411 to maintain a stable pressure difference without additional power output, while significantly reducing the transport resistance of the cooling and depressurizing airflows, further lowering the overall energy consumption of the fan 3.

[0083] Please see Figure 9 In some embodiments of this application, the support ring 344 has an elliptical cross-section in the axial direction, and the major axis of the cross-section is perpendicular to the axial direction.

[0084] The axial cross-section of the support ring 344 is elliptical with its major axis perpendicular to the axial direction, creating a wider bearing surface in the radial direction. The centrifugal force generated by the high-speed rotation of the integrated blade 340 mainly acts radially on the support ring 344. The design of the major axis perpendicular to the axial direction allows the support ring 344 to bear the radial load with a larger cross-sectional area, distributing the force transmitted by the integrated blade 340 more evenly throughout the annular structure and avoiding deformation of the support ring 344 due to radial force concentration. Compared to a circular cross-section, the elliptical cross-section significantly improves the radial bending stiffness, further enhancing the constraint effect on the radial deformation of the integrated blade 340.

[0085] The integrated blade 340 extends radially inward and outward from the support ring 344, and its connection point with the support ring 344 primarily bears radial shear force. The major axis of the elliptical cross-section precisely matches the force direction of the integrated blade 340. The cross-sectional thickness and area at the connection point are larger, enabling more stable transmission of the force generated by the blade and reducing stress concentration at the connection point. Simultaneously, the streamlined profile of the elliptical cross-section makes the connection between the support ring 344 and the integrated blade 340 smoother, avoiding localized stress peaks caused by right angles or abrupt structural changes, and improving the overall fatigue resistance of the structure.

[0086] The elliptical cross-section has a naturally streamlined profile, which significantly reduces airflow resistance within the through-channel 346 compared to square or irregular cross-sections. When airflow moves along the through-channel 346 from the first impeller 341 side to the second impeller 342 side, it flows smoothly along the elliptical surface of the support ring 344 without significant airflow impact or turbulence. This streamlined design allows the airflow to maintain a stable velocity within the through-channel 346 on both the inner and outer sides of the support ring 344, avoiding energy loss due to abrupt changes in cross-section and providing a superior airflow environment for uniform pressure differential transmission.

[0087] Please see Figure 5 In some embodiments of this application, the inner and outer diameters of the support ring 344 satisfy: (Q1-Q2) / 10 < Q3-Q4, where Q1 represents the outer diameter of the integral blade 340, Q2 represents the inner diameter of the integral blade 340, Q3 represents the outer diameter of the support ring 344, and Q4 represents the inner diameter of the support ring 344. That is, Q1-Q2 represents the radial width of the integral blade 340, and Q3-Q4 represents the radial width of the support ring 344.

[0088] When the integrated blade 340 rotates at high speed, it generates a huge centrifugal force radially outward, and this centrifugal force increases with the blade radius, becoming particularly significant at the blade tip. The radial width of the support ring 344 exceeds 1 / 10 of the radial width of the integrated blade 340, forming a sufficient radial load-bearing range. This allows the connection points between the integrated blade 340 and the support ring 344 to be evenly distributed radially, rather than concentrated in a narrow area. The centrifugal force is transmitted to the support ring 344 through multiple dispersed connection points, significantly reducing the stress on each connection point and effectively preventing cracking at the blade root or connection points due to excessive local stress.

[0089] In some embodiments of this application, the inner and outer diameters of the support ring 344 also satisfy: Q3-Q4 < (Q1-Q2) / 2. A support ring 344 with a radial width exceeding half that of the blade will form excessive support. Such support not only fails to significantly improve the overall load-bearing capacity, but also increases the inertial load when the impeller assembly 34 rotates due to the increased weight of the support ring 344 itself. The drive shaft needs to output additional power to overcome inertia, indirectly exacerbating the stress burden on the shaft and blade. Limiting the upper limit of the width can accurately match the requirements of the core stress area and avoid structural load redundancy caused by ineffective support. Furthermore, the width of the support ring 344 directly affects the radial dimension of the through channel 346 between adjacent blades. If the width exceeds half of the radial width of the integral blade 340, it will significantly compress the radial flow space of the through channel 346.

[0090] Please see Figure 10 and Figure 11 In some embodiments of this application, the axial height of the first impeller 341 is greater than that of the second impeller 342. The greater axial height of the first impeller 341 allows its blades to sweep across a thicker air layer during rotation, thus pushing more air into the fan 3 with each revolution. In contrast, the smaller axial height of the second impeller 342 results in a thinner air layer being swept across, and consequently, less air is driven per unit time. This difference in driving force directly translates into a difference in flow rate, causing the airflow intake of the first air inlet 31 to be greater than that of the second air inlet 32.

[0091] The difference in axial height between the first impeller 341 and the second impeller 342 achieves precise adaptation and simultaneous protection for the two core requirements of heat dissipation and pressure relief. For the continuous and high-capacity heat dissipation needs of heating elements, temperature controllers, and other devices within the partition space, the larger axial height of the first impeller 341 results in high air pressure and a large flow rate, quickly removing accumulated heat from the partition space and drawing in ambient air to form an efficient heat dissipation cycle, preventing performance degradation or damage to devices due to high temperatures. Simultaneously, addressing the intermittent and moderate pressure relief requirements of the inner cavity 2, the smaller axial height of the second impeller 342 creates low air pressure and a small flow rate. In the early stages of baking, it maintains stability within the cavity through a small amount of exhaust, and promptly removes excess gas during periods of rapid steam increase to prevent pressure exceeding limits. It also prevents excessive moisture loss within the cavity, avoiding problems such as food drying out and poor expansion. Through the differentiated design of their axial heights, both impellers achieve a balance between enhanced heat dissipation efficiency and balanced pressure relief control.

[0092] Please see Figure 11 In some embodiments of this application, the axial height H1 of the first impeller 341 and the axial height H2 of the second impeller 342 satisfy: H2 / H1≥1 / 10.

[0093] The axial height determines the airflow capture volume and wind pressure output capacity of the impeller. If H2 / H1 is less than 1 / 10, it means that the axial height of the second impeller 342 is too small. Correspondingly, in terms of wind pressure, the negative pressure suction generated by the second impeller 342 will be significantly weaker. When the steam in the inner cavity 2 of the oven 100 increases sharply due to food vaporization, the weak suction cannot promptly remove the high-pressure gas from the pressure relief hole 21, causing pressure to continuously accumulate inside the cavity. This may not only affect the baking quality of the food but also pose a safety risk of excessive pressure causing the oven 100 door to open and high-temperature gas to splash. In terms of flow rate, the insufficient axial height results in insufficient air drive per unit time for the second impeller 342. Even if negative pressure can be formed, it is difficult to quickly discharge sufficient gas, also causing a lag in pressure relief response.

[0094] In some embodiments of this application, the axial height H1 of the first impeller 341 and the axial height H2 of the second impeller 342 satisfy: H2 / H1≤1 / 4. If H2 / H1 is greater than 1 / 10, the axial height of the second impeller 342 is too large, and its airflow capture volume will approach or even partially encroach on the performance space of the first impeller 341. This will lead to a significant increase in the wind pressure and flow rate of the second impeller 342. On the one hand, this may divert the power output of the fan 3, weakening the suction force of the first impeller 341 used to drive the cooling airflow, making it unable to quickly remove the heat accumulated in the gap space, and causing the risk of high-temperature aging of the device; on the other hand, an excessively large second impeller 342 will increase the overall load of the fan 3, which may lead to a decrease in speed and further weaken the heat dissipation efficiency.

[0095] During baking, excessive negative pressure suction will continuously draw gas out of the inner cavity 2, leading to two problems: First, rapid loss of humidity inside the cavity causes the food surface to dry prematurely due to insufficient moisture, resulting in a hard exterior and raw interior, affecting the uniformity of cooking; second, persistently low pressure will disrupt the expansion and shaping mechanisms of the food, especially significantly affecting foods that rely on the pressure inside the cavity for structural support. By controlling H2 / H1 ≤ 1 / 4, the performance of the second impeller 342 is kept within a sufficient range, allowing it to only expel excess gas exceeding the safety threshold. This avoids the risk of excessive pressure and maintains a dynamic balance between humidity and pressure inside the cavity, creating a suitable baking environment for the food and ensuring the quality of the finished product.

[0096] In summary, the aforementioned restrictions on H2 / H1 ensure that the second impeller 342 has basic pressure relief capabilities, preventing the risk of pressure buildup, while the upper limit H2 / H1 ≤ 1 / 4 ensures the heat dissipation performance advantage of the first impeller 341, preventing excessive pressure relief and insufficient heat dissipation. This range achieves a precise match between heat dissipation and pressure relief functions, while balancing the stress stability and structural compactness of the impeller assembly 34. Ultimately, this optimizes the energy consumption and lifespan of the equipment while ensuring the safe operation and baking quality of the oven 100.

[0097] For impeller assemblies with through channels 346, since they are suitable for slower speeds, the corresponding integrated blades 340 typically have an exit angle between 30° and 90°.

[0098] Please see Figure 4 and Figure 12 In some embodiments of this application, the oven 100 further includes a first partition 51 and a second partition 52 disposed between the outer shell 1 and the inner cavity 2, with the first partition 51 located on the side of the second partition 52 closer to the outer shell 1; a fan cavity 36 and an exhaust duct 4 are formed between the first partition 51 and the second partition 52, and an air outlet 33 is formed on the side of the fan cavity 36, which is connected to the exhaust duct 4; an impeller assembly 34 is disposed in the fan cavity 36, with the first impeller 341 facing the first partition 51, and the first air inlet 31 disposed on the first partition 51 at a position opposite to the first impeller 341; the second impeller 342 faces the second partition 52, and the second air inlet 32 ​​is disposed on the second partition 52 at a position opposite to the second impeller 342.

[0099] The first partition 51 and the second partition 52 are arranged in a layered layout. The first partition 51 is close to the outer shell 1, and the second partition 52 is close to the inner cavity 2. The space between them is divided into a fan cavity 36 and an exhaust duct 4, forming a double-layered isolation and zoned airflow structure. The first impeller 341 faces the first partition 51 and is directly opposite the first air inlet 31, while the second impeller 342 faces the second partition 52 and is directly opposite the second air inlet 32. This allows the cooling airflow and the pressure relief airflow to be drawn in from their respective air inlets and to be completely independent before entering the fan cavity 36. After entering through the first air inlet 31, the cooling airflow is driven to the fan cavity 36 by the first impeller 341, and then enters the exhaust duct 4 through the side air outlet 33. After being drawn in through the second air inlet 32, the pressure relief airflow first completes pressure balance in the fan cavity 36, and then is discharged together through the flow path of the exhaust duct 4.

[0100] The cooling airflow enters directionally from the first air inlet 31, flowing through the fan cavity 36 and exhaust duct 4 without backflowing into the inner cavity 2 and affecting the baking environment. The pressure relief airflow is independently drawn in from the second air inlet 32, only merging with the cooling airflow in the fan cavity 36, avoiding mixing with the cooling airflow and thus preventing a decrease in heat exchange efficiency. The paths of the two types of airflow are clearly defined, and the cooling and pressure relief functions do not interfere with each other, significantly improving their respective operating efficiency.

[0101] The fan cavity 36, exhaust duct 4, and impeller assembly 34 are integrated between the first partition 51 and the second partition 52, significantly improving space utilization and adapting to the limited installation environment inside the oven 100. At the same time, the airflow path is greatly shortened, the process of heat dissipation airflow from intake to exhaust is simpler, and the depressurized airflow can be discharged without an additional channel, reducing energy loss during airflow transportation, reducing the operating energy consumption of the fan 3, and improving the overall energy efficiency of the equipment.

[0102] Please see Figure 12 , Figure 13 and Figure 14 In some embodiments of this application, a pressure relief channel 53 is provided between the second air inlet 32 ​​and the pressure relief hole 21, and the cross-sectional size of the pressure relief channel 53 gradually increases from the pressure relief hole 21 to the second air inlet 32.

[0103] The pressure relief channel 53 has a gradually expanding cross-sectional structure, similar to a trumpet shape. When the high-pressure gas in the inner cavity 2 enters the channel through the pressure relief hole 21 with a smaller cross-section, the airflow space expands as the channel cross-section gradually increases, the gas density per unit volume decreases, the flow velocity slows down, and the gas pressure is initially released. This channel shape, which first contracts and then expands, allows the high-pressure airflow to complete smooth pressure reduction before reaching the second air inlet 32, preventing the airflow from impacting the second impeller 342 at high speed. At the same time, the gradually changing cross-sectional shape reduces abrupt changes in airflow within the channel, significantly reducing vortex resistance caused by path changes, laying the foundation for wind resistance control.

[0104] The second impeller 342 can depressurize without strong negative pressure. If the airflow directly enters the second inlet 32 ​​at high pressure and high speed, it may cause a sudden increase in impeller load or even cause airflow turbulence. The gradually increasing cross-section allows the airflow to complete pressure buffering within the channel. The pressure and velocity when it reaches the second inlet 32 ​​are perfectly matched with the driving capacity of the second impeller 342, forming an orderly connection between channel pressure reduction and impeller exhaust. This smooth connection avoids violent impact between the airflow and the impeller blades, reducing vibration and noise caused by airflow impact at the source, while also reducing airflow resistance when the impeller rotates.

[0105] The gradually changing cross-section allows for smoother airflow, avoiding eddy current and impact resistance caused by abrupt changes in cross-section. This significantly reduces energy loss as the airflow passes through the channel, lowering the additional load on the fan 3 driving the depressurized airflow. Furthermore, the stable airflow reduces frictional noise from the channel walls and avoids vibration noise caused by high-speed airflow impacting the impeller, resulting in a significant reduction in the overall noise level of the oven 100 during operation and improving the user experience.

[0106] In some embodiments, both the pressure relief hole 21 and the second air inlet 32 ​​include multiple small holes. When the high-pressure gas in the inner cavity 2 reaches the pressure relief hole 21, it is divided into multiple independent fine airflows by the multiple small holes, breaking the concentrated airflow stream formed by a single hole. After these dispersed fine airflows enter the pressure relief channel 53, they can fill the channel space more evenly, avoiding uneven flow velocity caused by excessively high local airflow density. When the airflow reaches the second air inlet 32, which also has a porous structure, it is again diverted and sorted by the small holes, further weakening the concentrated impact force of the airflow, allowing the airflow to enter the fan cavity 36 in a smoother state. For example Figure 12 and Figure 13 In the embodiment shown, both the pressure relief hole 21 and the second air inlet 32 ​​contain five small holes.

[0107] Please see Figure 13 and Figure 14 The pressure relief channel 53 has a trumpet-shaped structure with a smaller opening at the bottom and a larger opening at the top. The top of the components of the pressure relief channel 53 is also provided with a connecting buckle 531. The second partition 52 is provided with a connecting hole at the corresponding position. The connecting buckle 531 can be inserted and rotated to lock into the connecting hole, thereby fixing the pressure relief channel 53.

[0108] For a more intuitive presentation, the table below shows the measured data of pressure relief and heat dissipation of the impeller assembly 34 in the embodiments of this application.

[0109] Design parameters Example 1 Example 2 Example 3 First / Second Impeller Height 13.5mm / 13.5mm 13.5mm / 13.5mm 22.3mm / 4.7mm First air inlet flow rate <![CDATA[0.6m 3 / h]]> <![CDATA[0.3m 3 / h]]> <![CDATA[0.2m 3 / h]]> Second air inlet flow rate <![CDATA[29.4m 3 / h]]> <![CDATA[33.4m 3 / h]]> <![CDATA[36.3m 3 / h]]> Traffic flow <![CDATA[30.1m 3 / h]]> <![CDATA[33.7m 3 / h]]> <![CDATA[36.6m 3 / h]]> Energy efficiency value 899W 886W 865W

[0110] In particular, Example 1 adopted Figure 7 The impeller assembly 34 shown in Embodiment 2 employs... Figure 5The impeller assembly 34 shown in Embodiment 3 employs... Figure 10 The impeller assembly 34 is shown. As can be seen from the table above, on the one hand, the oven 100 in each embodiment achieves minimal heat loss from the inner cavity 2, effectively reducing unnecessary energy waste and thus achieving better energy-saving effects; on the other hand, its heat dissipation system can maintain a large airflow, quickly and efficiently dissipating the heat accumulated inside the equipment, thereby achieving better heat dissipation. Furthermore, from Embodiment 1 to Embodiment 3, the airflow at the end of the inner cavity 2 gradually decreases, resulting in a gradual reduction in heat loss and making the oven 100 more energy-efficient; the heat dissipation flow gradually increases, indicating a gradual enhancement in heat dissipation effect; and the energy efficiency value also gradually increases.

[0111] As can be seen from the table above, in this embodiment, on the one hand, it can achieve minimal heat loss from the inner cavity 2, effectively reducing unnecessary energy consumption and thus achieving better energy-saving effect; on the other hand, its heat dissipation system can maintain a large airflow, which can quickly and efficiently dissipate the heat accumulated inside the equipment, thereby achieving better heat dissipation effect.

[0112] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An oven, characterized in that, The oven includes: The outer casing; a heat dissipation duct is provided inside the outer casing; Inner cavity; the inner cavity is disposed within the outer shell, and the inner cavity is provided with a pressure relief hole; The fan includes a first air inlet, a second air inlet, and an air outlet. The first air inlet is connected to the heat dissipation duct, and the second air inlet is connected to the pressure relief hole. Exhaust duct; the exhaust duct is connected to the air outlet; The fan also includes an impeller assembly, which includes a first impeller and a second impeller, and the first impeller and the second impeller are coaxially arranged. The first air inlet and the second air inlet are respectively located at both ends of the fan's axial direction. The first air inlet is opposite to the first impeller so that airflow is driven by the first impeller to enter the fan from the first air inlet. The second air inlet is opposite to the second impeller so that airflow is driven by the second impeller to enter the fan from the second air inlet. The air outlet is located on the radial side of the fan so that airflow can be discharged from the fan. The impeller assembly is provided with a through channel along the axial direction to connect the space where the first impeller is located and the space where the second impeller is located. The wind pressure generated by the first impeller is greater than the wind pressure generated by the second impeller, so as to form a pressure difference from the first impeller to the second impeller in the through channel.

2. The oven as described in claim 1, characterized in that, The first impeller includes a plurality of first blades spaced apart along the circumferential direction, and the second impeller includes a plurality of second blades spaced apart along the circumferential direction; the number of first blades and second blades are equal, and each first blade is connected to a corresponding second blade to form an integral blade, so that the first blade and the second impeller form an integral blade, and the interval between adjacent integral blades forms the through channel.

3. The oven as described in claim 2, characterized in that, The impeller assembly also includes a support member, to which multiple integral blades are connected.

4. The oven as described in claim 3, characterized in that, The support member includes a support ring, which is coaxially connected to the integral blade. The integral blade extends from the radially inner side of the support ring to the radially outer side of the support ring. Through channels are formed between adjacent integral blades on the radially inner side and the radially outer side of the support ring, respectively. Alternatively, the support member includes a support disk, the support disk and the integral blade are coaxially connected, and the integral blade extends to the radially outer side of the support disk; on the radially outer side of the support disk, the through channel is formed between adjacent integral blades.

5. The oven as described in claim 4, characterized in that, The cross-section of the support ring in the axial direction is elliptical, and the major axis of the cross-section is perpendicular to the axial direction.

6. The oven as described in claim 4 or 5, characterized in that, The inner and outer diameters of the support ring satisfy: (Q1-Q2) / 10 < Q3-Q4, and / or, Q3-Q4 < (Q1-Q2) / 2; where Q1 represents the outer diameter of the integrated blade, Q2 represents the inner diameter of the integrated blade, Q3 represents the outer diameter of the support ring, and Q4 represents the inner diameter of the support ring.

7. The oven as described in claim 4 or 5, characterized in that, The axial height of the first impeller is greater than the axial height of the second impeller.

8. The oven as described in claim 4 or 5, characterized in that, The axial height H1 of the first impeller and the axial height H2 of the second impeller satisfy: 1 / 10 ≤ H2 / H1 ≤ 1 / 4.

9. The oven as described in any one of claims 1 to 8, characterized in that, The oven further includes a first partition and a second partition disposed between the outer shell and the inner cavity, wherein the first partition is located on the side of the second partition closer to the outer shell; A fan cavity and an exhaust duct are formed between the first partition and the second partition. The air outlet is formed on the side of the fan cavity and is connected to the exhaust duct through the air outlet. The impeller assembly is disposed within the fan cavity, with the first impeller facing the first partition and the first air inlet disposed on the first partition at a position opposite to the first impeller; the second impeller faces the second partition and the second air inlet is disposed on the second partition at a position opposite to the second impeller.

10. The oven as described in claim 9, characterized in that, A connecting channel is provided between the second air inlet and the pressure relief hole, and the cross-sectional dimensions of the connecting channel gradually increase from the pressure relief hole to the second air inlet.

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