Blower with noise reduction structure

Abstract

The utility model relates to a blower with noise reduction structure belongs to new energy automobile air conditioning technical field. Through setting up the flow guide plate and the support rib at the blower air inlet, the air inlet is divided into the inside air inlet channel and the outside air inlet channel through the flow guide plate pre -shunt to the air inlet, the airflow is split and inhibits the backflow gas, and the flow field of volute air inlet area is straightened, airflow uniformity and stability are effectively improved, airflow separation and vortex generation are reduced from the source, and source noise reduction is realized. The flow guide plate extends into the impeller area, and the backflow gas in the volute hits the air inlet from the physical level, and the main path of noise aggravation is cut off. The support rib of prime number quantity is obliquely arranged between the volute and the flow guide plate, the flow guide plate is fixed at the air inlet, and resonance noise possibly caused by impeller rotation order matching is effectively avoided.

Description

Technical Field

[0001] This utility model belongs to the field of new energy vehicle air conditioning technology, and relates to a blower with a noise reduction structure. Background Technology

[0002] As the automotive industry accelerates its trend towards miniaturization and lightweighting, the design of automotive air conditioning systems faces unprecedented challenges. Particularly in compact front and rear air conditioning systems, the widespread use of PTC (Positive Temperature Coefficient) thermistors has become essential for precise heater control. However, due to space constraints, the layout of the vehicle's ductwork is limited, forcing a narrowing of the airflow channels within the air conditioning unit and causing a sharp increase in the drag coefficient of the connecting pipe sections. This deterioration of the working environment directly causes the blower to deviate from its normal operating range. The high drag easily generates severe airflow separation and turbulence near the air inlet, resulting in significant aerodynamic noise such as a "popping" sound.

[0003] The root cause lies in the fact that, under such high wind resistance conditions, the traditional design of the volute and impeller in air conditioning unit blowers cannot cover the extreme operating range. When airflow impacts the inlet at high speed, due to the traditional design of the volute, some of the airflow accelerated by the impeller cannot be smoothly guided and converted, instead forming a significant backflow zone at the tail of the volute. This reverse-flowing air mass collides violently with the forward-incident airflow, further exacerbating flow field turbulence and aerodynamic noise.

[0004] Traditional noise reduction solutions have limitations. Current industry-wide passive noise reduction methods, such as wrapping with sound-absorbing cotton, essentially reduce noise transmission by absorbing and blocking sound waves. However, this passive approach only addresses the symptoms, not the root cause. Its main drawbacks are: first, sound-absorbing materials increase system weight, contradicting the trend towards lightweight vehicles; second, the assembly process of multi-layered composite materials is complex, significantly increasing manufacturing costs; and third, passive noise reduction has limited effectiveness against low- and mid-frequency noise. More importantly, passive solutions cannot eliminate the root cause of noise generation.

[0005] The existing design of the volute and impeller connection has revealed significant flaws. Therefore, developing new technologies capable of actively adjusting flow field characteristics has become crucial for solving the noise problem in compact air conditioning systems. Utility Model Content

[0006] In view of this, the purpose of this utility model is to provide a blower with a noise reduction structure, which straightens the flow field from the source and blocks and suppresses backflow gas through physical barriers, thereby achieving efficient noise reduction.

[0007] To achieve the above objectives, this utility model provides the following technical solution: A blower with a noise reduction structure is disclosed. The blower has a hollow impeller and an annular guide plate inside the air inlet. The guide plate is fixed to the blower's volute by multiple support ribs and is coaxial with the air inlet. The guide plate is trumpet-shaped, with its small end located at the air inlet end of the air inlet and its large end extending from the air inlet into the volute along the airflow direction. The large end extends into the hollow area inside the impeller, dividing the air inlet into an inner air inlet channel and an outer air inlet channel to separate the airflow and suppress backflow.

[0008] Optionally, the generatrix constituting the horn shape of the deflector can be a curve, a straight line, or a combination of both.

[0009] Optionally, the inner air intake channel is provided with an annular radial air intake grille fixed to the small end of the guide plate.

[0010] Optionally, the projected area of ​​the small end of the guide plate on the air inlet is 1 / 2 to 3 / 4 of the area of ​​the air inlet.

[0011] Optionally, the support ribs are arranged at a set angle to the radial direction of the air inlet, and are distributed obliquely in the outer air inlet channel in a vortex shape, with one end connected to the guide plate and the other end connected to the volute.

[0012] Optionally, all the support ribs are set at the same tilt angle, and the rotation direction of the support ribs is the same as the rotation direction of the impeller.

[0013] Optionally, the number of the supporting ribs is a prime number greater than 1.

[0014] Optionally, the number of supporting ribs is 3, 5, 7 or 11.

[0015] Optionally, the outer edge of the volute near the guide plate is curved in an S-shape and bends inward toward the inside of the blower. The curvature of the generatrix forming the trumpet shape of the guide plate matches the curvature of the outer edge of the volute to form an outer air intake channel.

[0016] The beneficial effects of this utility model are as follows: This utility model relates to a noise reduction design for improving aerodynamic noise in automotive air conditioning units. By installing a guide vane and support ribs at the blower inlet of the air conditioning unit, the guide vane pre-divides the intake air, actively optimizing the airflow field and effectively improving the uniformity of airflow entering the impeller. This reduces airflow separation and turbulence at the source, achieving noise reduction from the outset. The guide vane extends radially into the impeller area, physically blocking the backflow of gas from the volute from rushing towards the air inlet, cutting off the main path for noise amplification. When the guide vane is arc-shaped, it matches the curvature of the S-shaped outer edge of the volute, smoothing the flow field in the air intake area of ​​the volute, making the airflow more stable and significantly eliminating aerodynamic noise such as "puffing" sounds. This utility model also specifies the use of a prime number of support ribs to fix the guide vane at the air inlet, effectively avoiding resonance noise that may be caused by matching the impeller's rotation order, demonstrating the comprehensiveness of the design.

[0017] This invention achieves comprehensive noise reduction from three levels: the source of airflow turbulence, the path of noise amplification, and the potential risk of structural resonance. It fundamentally solves the problem of aerodynamic noise and can reduce or eliminate traditional passive noise reduction methods, such as external sound insulation materials, thereby reducing material costs and assembly complexity.

[0018] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the blower structure of an air conditioning unit; Figure 2 for Figure 1 Enlarged schematic diagram of part A; Figure 3 This is a cross-sectional view of the volute. Figure 4 This is an enlarged schematic diagram of the air inlet of the volute. Figure 5 This is a cross-sectional view of the air inlet guide vane.

[0020] Figure label: 1. Guide vane, 2. Support rib, 3. Impeller shaft, 4. Inlet grille, 5. Volute, 6. Impeller. Detailed Implementation

[0021] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0022] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0023] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model 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, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0024] Example 1 Please see Figures 1-5 This is a blower with a noise reduction structure. The blower's impeller 6 is hollow inside, and an annular guide plate 1 is installed inside the blower's air inlet. The guide plate 1 is fixed to the blower's volute 5 by multiple support ribs 2 and is coaxial with the air inlet. The guide plate 1 is trumpet-shaped, with the small end located at the air inlet end of the air inlet, and the large end extending from the air inlet into the volute 5 in accordance with the airflow direction. The large end extends into the hollow area inside the impeller 6, dividing the air inlet into an inner air inlet channel and an outer air inlet channel to separate the airflow and suppress backflow gas. This effectively improves the uniformity of the airflow entering the impeller 6, reduces airflow separation and vortex generation, and achieves noise reduction at the source. The extension into the impeller 6 rotates around the impeller shaft 3, pumping external air into the blower from one side of the guide plate 1. The guide plate 1 physically blocks the backflow gas thrown out by the impeller 6 from rushing towards the air inlet, cutting off the main path of noise amplification.

[0025] Furthermore, the generatrix constituting the trumpet shape of the deflector 1 is a curve, a straight line, or a combination of both.

[0026] Furthermore, an annular radial air intake grille 4 is fixed to the small end of the guide plate 1 on the inner air intake channel. The projected area of ​​the small end of the guide plate 1 on the air intake is 1 / 2 to 3 / 4 of the air intake area. In some embodiments of this invention, the projected area of ​​the small end of the guide plate 1 on the air intake is 2 / 3 of the air intake area. That is, through the guide plate 1 and the air intake grille 4, the air entering the volute 5 is divided in a ratio of approximately 2:1. For every 2 portions of air entering through the air intake grille 4, 1 portion of air enters through the small end of the guide plate 1. The structure of this invention allows airflow to enter from different paths, further dispersing the incoming flow and preventing excessive concentration of airflow in a single channel, thus helping to improve airflow uniformity. By optimizing the projected area of ​​the guide plate 1, sufficient guiding area is provided to improve the flow field, while avoiding excessive obstruction of the air intake, which would significantly affect the airflow and fan efficiency.

[0027] In practical applications, the height of the guide vane 1 and its depth into the impeller 6 are key parameters affecting the noise reduction effect, and need to be optimized according to the specific model.

[0028] Example 2 Based on Embodiment 1 above, this embodiment specifies that the generatrix constituting the trumpet shape of the guide plate 1 is a curve or a combination of curves and straight lines. The outer edge of the volute 5 near the guide plate 1 is curved in an S-shape and bends inward toward the inside of the blower. The curvature of the generatrix constituting the trumpet shape of the guide plate 1 matches the curvature of the outer edge of the volute 5 to form an outer air intake channel. The outer air intake channel smooths the flow field at the air inlet of the volute 5, making the incoming airflow more stable.

[0029] Example 3 In this embodiment, the support ribs 2 are further defined to form a set angle with the radial direction of the air inlet, and are distributed obliquely in a vortex shape within the outer air inlet channel. One end of each rib is connected to the guide plate 1, and the other end is connected to the volute 5, thus fixing the guide plate 1 to the volute 5. Furthermore, all support ribs 2 are uniformly arranged at the same inclination angle, and the rotation direction of the support ribs 2 is the same as the rotation direction of the impeller 6, which helps to streamline the airflow field at the air inlet.

[0030] All support ribs 2 are inclined in the same direction of rotation on the guide plate 1, and the number of support ribs 2 is a prime number greater than 1. This avoids resonance with the airflow pulsations generated when the impeller 6 rotates, reduces new order noise, and demonstrates the comprehensiveness of the design. Specifically, resonance occurs when the frequencies of "guide plate 1 + support ribs 2" match those of the impeller 6. If the number of support ribs 2 is a composite number, the excitation generated by the rotation of the impeller 6 (especially its harmonic frequencies) can easily coincide with certain structural modal frequencies determined by the number of support ribs 2. For example, the natural frequencies of a symmetrical structure with 8 support ribs 2 may match the 4th, 2nd, or even 8th order harmonic excitation of the impeller 6, thus triggering multi-order resonance. In this invention, the number of support ribs 2 is set to a prime number, which disrupts the symmetry between the structure and the rotational excitation of the impeller 6. Since a prime number can only be divided by 1 and itself, it is difficult for the harmonic frequency of the periodic aerodynamic excitation generated by the impeller 6 to achieve an "integer multiple" precise match with the main modal frequency of the prime number support rib 2 structure, thereby avoiding the generation of resonance noise between the "guide plate 1 + support rib 2" and the impeller 6.

[0031] In some embodiments of this utility model, the number of support ribs 2 is preferably 3, 5, 7 or 11.

[0032] This invention achieves comprehensive noise reduction from three levels: the source of airflow turbulence, the path of noise amplification, and the potential risk of structural resonance. It fundamentally solves the problem of aerodynamic noise and can reduce or eliminate traditional passive noise reduction methods, such as external sound insulation materials, thereby reducing material costs and assembly complexity.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A blower with a noise reduction structure, wherein the impeller (6) of the blower is hollow inside, characterized in that: The blower has an annular guide plate (1) inside the air inlet. The guide plate (1) is fixed to the volute (5) of the blower by multiple support ribs (2) and is coaxial with the air inlet. The guide plate (1) is trumpet-shaped, with the small end located at the air inlet end of the air inlet and the large end extending from the air inlet into the volute (5) in accordance with the air inlet flow direction. The large end extends into the inner hollow area of ​​the impeller (6), dividing the air inlet into an inner air inlet channel and an outer air inlet channel to separate the airflow and suppress backflow gas.

2. The blower with noise reduction structure according to claim 1, characterized in that: The generatrix constituting the horn shape of the guide plate (1) is a curve, a straight line, or a combination of both.

3. The blower with a noise reduction structure according to claim 1, characterized in that: The inner air intake channel is provided with an annular radial air intake grille (4) fixed to the small end of the guide plate (1).

4. The blower with a noise reduction structure according to claim 1, characterized in that: The projected area of ​​the small end of the guide plate (1) on the air inlet is 1 / 2 to 3 / 4 of the area of ​​the air inlet.

5. The blower with a noise reduction structure according to claim 1, characterized in that: The supporting rib (2) forms a set angle with the radial direction of the air inlet and is distributed in a vortex-like inclined manner in the outer air inlet channel. One end is connected to the guide plate (1) and the other end is connected to the volute (5).

6. The blower with a noise reduction structure according to claim 5, characterized in that: All the support ribs (2) are set at the same tilt angle, and the rotation direction of the support ribs (2) is the same as the rotation direction of the impeller (6).

7. The blower with a noise reduction structure according to claim 1, characterized in that: The number of the supporting ribs (2) is a prime number greater than 1.

8. The blower with a noise reduction structure according to claim 7, characterized in that: The number of the supporting ribs (2) is 3, 5, 7 or 11.

Images