An impeller

Abstract

The application relates to the field of ventilation and cooling technology of rail transit vehicles, in particular to a kind of impeller, including impeller front disc, impeller rear disc, blade and shaft sleeve, blade is connected between impeller front disc and impeller rear disc, impeller rear disc is coaxial with the driving end of motor by shaft sleeve Connection, impeller front disc is formed by arc segment rotation, one side is equipped with small-bore port compatible with air inlet, the port is smoothly tapered flared design along the direction of airflow inflow, the ratio of front disc inlet diameter and front disc outer diameter is 0.75-0.82, the ratio of the height of the inlet end of the impeller front disc and the height of the impeller is 0.1-0.3;Impeller rear disc is flat disc, the ratio of rear disc diameter and front disc outer diameter is 0.9-1.The application optimizes the structure parameters, not only widens the internal effective flow section, but also guarantees the continuity and symmetry of flow channel, reduces the peripheral airflow and vortex of shaft sleeve, has the advantages of small flow field interference and strong flow capacity.

Description

Technical Field

[0001] This application relates to the field of ventilation and cooling technology for rail transit vehicles, specifically to an optimized design technology for the impeller in a multi-bladed forward centrifugal fan applied to the ventilation and cooling system of a traction motor in rail transit vehicles. Background Technology

[0002] As rail transit vehicles continue to develop towards high speed and heavy load, the traction motor, as the core power equipment of the vehicle, is experiencing an increasing heat load during operation. The ventilation and cooling system is a key component in ensuring the insulation life and operational reliability of the traction motor, and its performance directly affects the overall efficiency and operational safety of the motor. In existing technologies, multi-blade forward centrifugal fans are widely used due to their advantages such as compact structure, high pressure coefficient, and suitability for installation in small spaces. However, for scenarios with limited axial installation space (such as integrated equipment and ventilation in confined cavities), the overall axial dimensions of the fan must be strictly controlled to meet installation requirements. However, existing fans of this type, when adapting to limited axial space, often have an excessively long shaft extending into the impeller to ensure transmission stability between the shaft and impeller. This structural design has significant drawbacks: firstly, the excessively long shaft significantly encroaches on the effective flow area inside the impeller, reducing the medium flow cross-section and directly limiting the fan's flow capacity, making it difficult to meet high-flow-rate requirements; secondly, the shaft sleeve extending into the impeller disrupts the continuity of the internal flow field, causing phenomena such as airflow around the impeller, eddies, and flow separation, which not only exacerbates energy loss and reduces fan operating efficiency but may also generate airflow pulsation and noise, affecting equipment operational stability. Currently, existing technologies have not proposed a targeted impeller structure optimization scheme to address the combined problem of "limited axial dimensions + insufficient flow capacity and flow field interference caused by excessive shaft extension".

[0003] Therefore, there is an urgent need to design an impeller structure that can reduce the interference of the bushing on the flow field and widen the effective flow channel without shortening the axial dimension, so as to solve the core technical pain points of existing fans and improve their adaptability and operating performance in confined space scenarios. Utility Model Content

[0004] The purpose of this application is to provide an impeller to solve the problems of limited effective flow channels, general flow capacity and flow field stability, and low operating efficiency in the prior art.

[0005] The embodiments of this application can be implemented through the following technical solutions: An impeller includes a front impeller plate, a rear impeller plate, blades, and a bushing. The blades are connected between the front impeller plate and the rear impeller plate, and the rear impeller plate is coaxially connected to the drive end of a motor via the bushing. The impeller front disc is formed by rotating an arc segment, and one side of it is provided with a small-diameter port adapted to the air inlet. This port has a smooth, gradually widening design along the airflow direction. The inlet diameter of the front disc is... With the outer diameter of the front disc The ratio ranges from 0.75 to 0.82, and the inlet height of the impeller front disc... With impeller height The ratio ranges from 0.1 to 0.3; The impeller rear plate is a flat plate with a diameter of [missing information]. With the outer diameter of the front disc The ratio is 0.9 to 1.

[0006] Furthermore, impeller height With the outer diameter of the front disc The ratio ranges from 0.45 to 0.55.

[0007] Furthermore, the inlet angle of the blade The exit angle of the blade is 45°-70°. The range is 152° to 168°.

[0008] Furthermore, the inlet diameter of the blade With the outer diameter of the front disc The ratio ranges from 0.35 to 0.42, and the outlet diameter of the blade is... With the outer diameter of the front disc The ratio ranges from 0.48 to 0.49.

[0009] Furthermore, the inlet diameter of the blade With the outer diameter of the front disc The ratio ranges from 0.35 to 0.42.

[0010] Furthermore, the outlet diameter of the blade With the outer diameter of the front disc The ratio ranges from 0.48 to 0.49.

[0011] Furthermore, the blade tilt angle of the blade The value range is 82°-88°.

[0012] Furthermore, the exit edge of the blade is provided with large waves and small waves. The large waves are distributed with 1 to 2 wavelengths in the width direction of the blade, and the ratio of their amplitude to wavelength is 0.05 to 0.07. The small waves are distributed with 10 to 15 wavelengths in the width direction of the blade, and the ratio of their amplitude to wavelength is 0.9 to 1.1.

[0013] Furthermore, the blade is formed by casting, and the toothed part at the tail of the blade is of uniform thickness, while the concave toothed part is thinned, forming a fishtail-like structure.

[0014] Furthermore, the number of blades is 24 to 36.

[0015] The impeller provided in the embodiments of this application has at least the following beneficial effects: The impeller front disc adopts a flared design formed by arc segment rotation. Through parameter optimization design, the effective flow cross section inside the impeller is effectively widened without increasing the axial dimension, offsetting the encroachment of excessive shaft extension on the flow space. The impeller rear disc adopts a flat disc structure and matches the outer edge dimension of the front disc. Through parameter optimization design, the continuity and symmetry of the flow channel are ensured, reducing the flow around and eddies of the airflow around the bushing, significantly reducing the interference of the bushing on the flow field. Ultimately, it improves the flow capacity and optimizes the flow field stability within the limited axial space, with advantages such as low flow field interference, strong flow capacity, and high practicality. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of an impeller according to this application; Figure 2 This is a partial side sectional view of an impeller according to this application; Figure 3 This is a schematic diagram of the forming line of the blade in this application; Figure 4 This is a schematic diagram of the blade tilt angle and blade exit edge adjustment in this application; Figure 5 This is a schematic diagram of the airfoil blade manufactured by casting in this application; Figure 6 This is a schematic diagram of the intersection lines between the blade and different cross sections in this application.

[0017] Numbers in the diagram 301 - Impeller front plate; 302 - Impeller rear plate; 303 - Blade; 4 - Shaft sleeve. Detailed Implementation

[0018] The present application will now be further described based on preferred embodiments and with reference to the accompanying drawings.

[0019] Furthermore, for ease of understanding, various components on the drawings have been enlarged or reduced, but this is not intended to limit the scope of protection of this application.

[0020] Singular forms of words also include plural meanings, and vice versa.

[0021] In the description of the embodiments of this application, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use, 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, and therefore should not be construed as a limitation on this application. In addition, in the description of this application, in order to distinguish different units, the terms "first," "second," etc. are used in this specification, but these are not limited by the manufacturing order, nor should they be construed as indicating or implying relative importance. Their names may differ in the detailed description and claims of this application.

[0022] The vocabulary used in this specification is for illustrative purposes and is not intended to limit the scope of this application. It should also be noted that, unless otherwise expressly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection via an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of these terms in this application.

[0023] like Figure 1 , Figure 2 As shown, an impeller includes an impeller front plate 301, an impeller rear plate 302, blades 303, and a bushing 4. The blades 303 are connected between the impeller front plate 301 and the impeller rear plate 302. The impeller rear plate 302 is coaxially connected to the drive end of the motor through the bushing 4 to ensure that the motor can drive the impeller to rotate synchronously and smoothly after starting.

[0024] In some preferred embodiments, the impeller front disc 301 is formed by rotating an arc segment, and one side of it is provided with a small-diameter port adapted to the air inlet. This port has a smooth, gradually widening design along the airflow direction, and its overall outline conforms to the airflow guide trajectory, forming a trumpet-shaped structure of "small-end air inlet, gradually widening guide". The small-diameter port of the impeller front disc 301 is the inlet, and the outwardly widening large-diameter port is the guide port. The diameter of the inlet is defined as the front disc inlet diameter. The diameter of the flow guide port is defined as the diameter of the outer edge of the front disc. The front disc inlet diameter With the outer diameter of the front disc The ratio ranges from 0.75 to 0.82 and is used to optimize the airflow introduction path and reduce inlet impact loss.

[0025] In some preferred embodiments, the axial length from the guide port to the inlet is equal to the inlet height. The axial length from the inlet end of the impeller front plate 301 to the impeller rear plate 302 is equal to the impeller height. The height of the inlet end of the impeller front disc 301 With impeller height The ratio ranges from 0.1 to 0.3, and is used to widen the effective flow cross section inside the impeller within a limited axial space, reduce the interference of the bushing on the flow field, and improve the impeller's flow capacity and flow field stability.

[0026] Through the above structural design, the arc-shaped impeller front disc 301 possesses multiple technical advantages: First, it can guide airflow along the arc surface to achieve smooth speed changes and turns, avoiding abrupt changes in airflow state, significantly reducing intake impact loss and eddy current loss, and improving airflow efficiency; Second, the arc profile can effectively buffer the direct impact between the airflow and the front disc surface, weakening the intensity of airflow disturbance, thereby suppressing the generation of turbulent noise. This advantage is more prominent under high-speed conditions, helping the fan achieve low-noise operation; Third, it can optimize the airflow angle of attack distribution at the blade inlet, allowing the airflow to adhere and flow evenly along the blade inlet, avoiding local airflow separation, which not only broadens the stable operating range of the fan but also greatly enhances its anti-surge capability, ensuring reliable operation of the fan under different operating conditions.

[0027] In some preferred embodiments, the impeller height With the outer diameter of the front disc The ratio ranges from 0.45 to 0.55, which allows for wider flow channels and matching of fan pressure characteristics within a limited axial space, while avoiding airflow stagnation or insufficient flow.

[0028] In some preferred embodiments, the impeller rear plate 302 is a flat plate, and the diameter of the impeller rear plate 302 is defined as the rear plate diameter. The diameter of the rear disc With the outer diameter of the front disc The ratio is 0.9 to 1, which is used to maximize the flow cross section, ensure the blade is under balanced stress and avoid airflow deviation, and improve the flow field stability and pressure transmission efficiency.

[0029] In some preferred embodiments, such as Figure 3 As shown, the blade 303 is formed by stretching a circular arc. The angle between the tangent at the inlet end of the blade 303 and the tangent in the impeller rotation direction is defined as the blade inlet angle. The inlet angle of the blade 303 The angle between the tangent at the exit end of the blade 303 and the tangent in the impeller rotation direction is defined as the blade exit angle, which is 45°-70°. The exit angle of the blade 303 The inlet diameter is defined as the radius of the arc along the axis perpendicular to the impeller's rotation axis at the inlet end of blade 303, which is 152° to 168°. The inlet diameter of the blade 303 With the outer diameter of the front disc The ratio ranges from 0.35 to 0.42. The radius of the arc along the axis perpendicular to the impeller rotation axis at the outlet end of the blade 303 is defined as the blade outlet diameter. The outlet diameter of blade 303 With the outer diameter of the front disc The ratio ranges from 0.48 to 0.49, and it is used to achieve smooth airflow introduction, full work and efficient output in structures with limited axial dimensions, while taking into account the flow capacity, pressure performance and operational stability of the fan.

[0030] In some preferred embodiments, the blades 303 are arranged in an inclined manner, keeping the maximum diameter at the impeller front disc 301 unchanged. Figure 4 As shown, the angle between the generatrix of the blade 303 and the impeller axis is defined as the blade tilt angle. The blade tilt angle of the blade 303 The value range is 82°-88°. The exit edge of the blade 303 adopts a composite cutting edge design of "large wave edge + small wave tooth": the large wave is distributed with 1 to 2 wavelengths in the width direction of the blade, and the ratio of its amplitude to wavelength is 0.05 to 0.07; the small wave is distributed with 10 to 15 wavelengths in the width direction of the blade, and the ratio of its amplitude to wavelength is 0.9 to 1.1.

[0031] Large wavy teeth are used to adjust the blade exit edge, minimizing the velocity difference between the same volute cross-section segments based on the internal flow field diagram. Small wavy teeth break up large-scale vortices detached from the trailing edge, suppressing airflow separation and weakening the generation and propagation of vortex noise, achieving the dual goals of "noise reduction + efficiency improvement". Sawtooths cut large vortices into multiple smaller vortices, reducing vortex intensity, lowering flow resistance, and improving fan efficiency; vortex shedding is one of the main sources of aerodynamic noise in fans, and smaller vortices have higher frequencies and more dispersed energy, avoiding frequencies sensitive to the human ear. At the same time, the sawtooth structure can disrupt the coherence of noise, achieving a noise reduction effect; the guiding effect of the sawtooth tips can improve the airflow adhesion state on the blade surface, reduce the separation zone area, and improve the fan's stable operating range and anti-surge capability.

[0032] like Figure 5 As shown, if the casting process is adopted, the blade cross section should preferably adopt a non-uniform thickness airfoil thickening design, in which the toothed part at the tail is kept of uniform thickness, while the concave toothed part is thinned to form a fishtail-like structure, which takes into account both structural strength and airflow adaptability.

[0033] The wind turbine blades of this invention are comparable in manufacturing difficulty to binary blades, yet possess diverse attributes: such as... Figure 6 As shown, any cross-section parallel to the back disk along the blade width direction exhibits differences in its intersection line with the blade in terms of inlet angle, outlet angle, inlet diameter, outlet diameter, intersection line length, and blade thickness. This allows for precise adaptation to complex flow fields, achieving a comprehensive improvement in "wide operating conditions, high efficiency, low noise, and high stability." These multi-faceted characteristics mitigate problems such as inlet airflow impact, mid-section turbulence separation, and outlet vortex shedding, resulting in a more uniform distribution of velocity and pressure fields within the impeller flow channel. This reduces local vortex losses, thereby improving the overall energy conversion efficiency. Simultaneously, it disperses vortex shedding frequencies, preventing the superposition of single-frequency noise and reducing the impact noise between the airflow and the blade.

[0034] In some preferred embodiments, the number of blades 303 is 24 to 36, to avoid insufficient pressure due to too few blades and flow channel blockage due to too many blades.

[0035] Preferably, the number of blades 303 is 32, which takes into account both flow efficiency and pressure performance, and can suppress airflow interference noise between blades, thus adapting to the complex flow field requirements of multi-blade systems.

[0036] The specific embodiments of this application have been described in detail above. For those skilled in the art, several improvements and modifications can be made to this application without departing from the principle of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. An impeller comprising a front impeller disc (301), a rear impeller disc (302), blades (303), and a bushing (4), wherein the blades (303) are connected between the front impeller disc (301) and the rear impeller disc (302), and the rear impeller disc (302) is coaxially connected to the drive end of a motor via the bushing (4), characterized in that: The impeller front disc (301) is formed by rotating an arc segment, and one side of it is provided with a small-diameter port adapted to the air inlet. This port has a smooth, gradually widening design along the airflow direction. The inlet diameter of the front disc is... With the outer diameter of the front disc The ratio ranges from 0.75 to 0.82, and the inlet height of the impeller front disc (301) is... With impeller height The ratio ranges from 0.1 to 0.3; The impeller back plate (302) is a flat plate, and the diameter of the back plate is... With the outer diameter of the front disc The ratio is 0.9 to 1.

2. The impeller according to claim 1, characterized in that: Impeller height With the outer diameter of the front disc The ratio ranges from 0.45 to 0.

55.

3. The impeller according to claim 1, characterized in that: The inlet angle of the blade (303) The exit angle of the blade (303) is 45°-70°. The range is 152° to 168°.

4. The impeller according to claim 1, characterized in that: The inlet diameter of the blade (303) With the outer diameter of the front disc The ratio ranges from 0.35 to 0.42, and the outlet diameter of the blade (303) is... With the outer diameter of the front disc The ratio ranges from 0.48 to 0.

49.

5. The impeller according to claim 1, characterized in that: The inlet diameter of the blade (303) With the outer diameter of the front disc The ratio ranges from 0.35 to 0.

42.

6. The impeller according to claim 1, characterized in that: The outlet diameter of the blade (303) With the outer diameter of the front disc The ratio ranges from 0.48 to 0.

49.

7. The impeller according to claim 1, characterized in that: The blade inclination angle of the blade (303) The value range is 82°-88°.

8. The impeller according to claim 1, characterized in that: The exit edge of the blade (303) is provided with large waves and small waves. The large waves are distributed with 1 to 2 wavelengths in the width direction of the blade, and the ratio of their amplitude to wavelength is 0.05 to 0.

07. The small waves are distributed with 10 to 15 wavelengths in the width direction of the blade, and the ratio of their amplitude to wavelength is 0.9 to 1.

1.

9. The impeller according to claim 1, characterized in that: The blade (303) is formed by casting process. The toothed part of the tail of the blade (303) is of equal thickness, and the concave toothed part is thinned, forming a fish tail structure.

10. The impeller according to claim 1, characterized in that: The number of blades (303) is 24 to 36.

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