A three-dimensional flow impeller

Abstract

The utility model belongs to the technical field of magnetic suspension equipment, disclose a kind of three-dimensional flow impeller, including impeller main part, the outer surface annular array of impeller main part has multiple spaced long blade and short blade, long blade and short blade are staggered arrangement, long blade is close to the position of outer edge of impeller main part and is provided with long blade tail edge, and the end of long blade tail edge is provided with first tail edge fillet, short blade is close to the position of outer edge of impeller main part and is provided with short blade tail edge, and the end of short blade tail edge is provided with second tail edge fillet;The utility model whole simple structure can reduce the mutation of section area, to reduce wake loss in turn, improve impeller efficiency, and for different forms, application scene impeller are all effective.

Description

Technical Field

[0001] This utility model belongs to the field of magnetic levitation equipment technology, specifically, it relates to a three-dimensional flow impeller. Background Technology

[0002] Currently, high-performance centrifugal compressors generally employ three-dimensional flow impellers. During the process of gas medium being drawn into the impeller and accelerated outwards, the velocity direction changes from axial to radial. The key to impeller efficiency lies in controlling the flow loss of the medium. A common structure for three-dimensional flow impellers is a rounded leading edge design for the blades, while the trailing edge is cut to a straight edge with the same diameter as the impeller's outer diameter. At the moment the airflow exits the impeller, a sudden change in cross-sectional area can be observed along the impeller span, resulting in wake loss. Due to limitations in impeller strength and deformation requirements, the thickness at the blade root is typically 3-5 mm, reflecting an efficiency loss of over 0.5% in terms of adiabatic efficiency.

[0003] like Figure 1-2 The image shows a commonly used three-dimensional flow impeller structure in the prior art. It can be seen that the impeller body 1 has multiple long blades 2 arranged in a ring on its surface. The trailing edge 22 of the long blades of this commonly used three-dimensional flow impeller is set as a straight edge 3. This makes it easy for the airflow to have a sudden change in cross-sectional area from the impeller span at the moment it flows out of the impeller, resulting in a loss of wake, which is limited by the requirements of impeller strength and deformation.

[0004] A Chinese patent application (CN2021104095142) discloses a combined three-dimensional flow impeller for use in a magnetic levitation vacuum pump. The impeller includes a front impeller, a rear impeller, and a locking mechanism. The bottom surface of the front impeller is an inner conical surface, and the top surface of the rear impeller is an outer conical surface, with the outer conical surface and the inner conical surface interlocked. The front and rear impellers are fixed by the locking mechanism, and the blades of the front and rear impellers extend in a one-to-one correspondence. The front impeller is made of titanium alloy, and the rear impeller is made of aluminum alloy. This combined three-dimensional flow impeller employs a combined structure, integrating two impellers of different materials into one unit. The front impeller is made of high-strength titanium alloy, and the rear impeller is made of high-strength aluminum alloy, thus ensuring the impeller's impact resistance and reliability while reducing its weight and manufacturing cost. However, the trailing edge in this application is designed with a straight edge, which leads to trail loss and low impeller efficiency. Utility Model Content

[0005] The main technical problem to be solved by this utility model is to provide a three-dimensional flow impeller with a simple overall structure, which can reduce the abrupt change in cross-sectional area, thereby reducing wake loss and improving impeller efficiency. At the same time, it is effective for impellers of different forms and application scenarios and has a wide range of applications.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution: A three-dimensional flow impeller includes an impeller body. The outer surface of the impeller body has a ring array of multiple long blades and short blades arranged at intervals. The long blades and short blades are arranged alternately. The long blades are provided with a trailing edge near the outer edge of the impeller body, and the end of the trailing edge of the long blade is provided with a first trailing edge rounded corner. The short blades are provided with a trailing edge near the outer edge of the impeller body, and the end of the trailing edge of the short blade is provided with a second trailing edge rounded corner.

[0007] The following are further optimizations of the above technical solution by this utility model: The longer blade is longer than the shorter blade.

[0008] Further optimization: The first and second trailing edge fillets are set to ellipses, and the aspect ratio of the ellipses of the first and second trailing edge fillets is set to 4-6.

[0009] Further optimization: The long blade is provided with a leading edge near the middle of the impeller body, and a first leading edge rounded corner is provided at the end of the leading edge of the long blade.

[0010] Further optimization: The short blade is provided with a leading edge near the middle of the impeller body, and a second leading edge fillet is provided at the end of the leading edge of the short blade.

[0011] Further optimization: The shapes of the first leading edge fillet and the second leading edge fillet are also set to ellipse, and the aspect ratio of the ellipse of the first leading edge fillet and the second leading edge fillet is set to 3-5.

[0012] This utility model adopts the above-mentioned technical solution, which is ingenious and reasonable in structure. The trailing edges of the long blades and the short blades on the three-dimensional flow impeller are respectively provided with a first trailing edge fillet and a second trailing edge fillet, which can reduce the boundary layer separation area of ​​the trailing edges of the long blades and the short blades, greatly reduce the gas medium loss in the trailing edges of the long blades and the short blades, and effectively improve the aerodynamic efficiency or hydraulic efficiency.

[0013] Furthermore, the structure of the first trailing edge fillet and the second trailing edge fillet can be applied to impeller blades of different forms and in different application scenarios, thus expanding the application range.

[0014] The structural design of the first and second trailing edge fillets is simple and easy to implement, requiring no complex processing technology.

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0016] Figure 1 This is an overall schematic diagram of a commonly used three-dimensional flow impeller structure in the embodiments of this utility model; Figure 2 This is an embodiment of the present utility model. Figure 1 Sectional view of AA in the middle; Figure 3 This is a schematic diagram of the overall structure in an embodiment of the present utility model; Figure 4 This is an embodiment of the present utility model. Figure 3 Cross-sectional view of the middle section (BB).

[0017] In the figure: 1. Impeller body; 11. Shaft hole; 2. Long blade; 21. Leading edge of long blade; 22. Trailing edge of long blade; 23. First leading edge fillet; 24. First trailing edge fillet; 3. Straight edge; 4. Short blade; 41. Leading edge of short blade; 42. Trailing edge of short blade; 43. Second leading edge fillet; 44. Second trailing edge fillet. Detailed Implementation

[0018] like Figure 3-4 As shown: A three-dimensional flow impeller includes an impeller body 1. The outer surface of the impeller body 1 has a ring array of multiple long blades 2 and short blades 4 arranged at intervals. The long blades 2 and short blades 4 are arranged alternately. The long blades 2 are provided with a long blade trailing edge 22 near the outer edge of the impeller body 1. The end of the long blade trailing edge 22 is provided with a first trailing edge rounded corner 24. The short blades 4 are provided with a short blade trailing edge 42 near the outer edge of the impeller body 1. The end of the short blade trailing edge 42 is provided with a second trailing edge rounded corner 44.

[0019] In this embodiment, a shaft hole 11 is provided at the middle position of the impeller body 1. The shaft hole 11 is used to connect with the main shaft of the fan. The specific connection method between the shaft hole 11 and the main shaft is known and will not be described in detail here. During the installation process, the coaxiality of the three-dimensional flow impeller and the main shaft should be ensured to avoid vibration and wear during operation.

[0020] The specific structure of the impeller body 1 is already known and will not be described in detail here.

[0021] The long blade 2 is longer than the short blade 4 and is arranged in a staggered ring array, which can effectively guide the airflow through the impeller and reduce the blockage and vortex phenomenon of the airflow at the blade inlet. The long blades 2 play a major role in the three-dimensional flow impeller, while the short blades 4, by sharing part of the load, play a role in suppressing secondary flow in the internal flow channel of the impeller and making its flow velocity distribution more uniform, which can further increase the working capacity of the three-dimensional flow impeller. Especially under high load or high speed conditions, it can significantly improve the output pressure of the three-dimensional flow impeller.

[0022] The first trailing edge fillet 24 and the second trailing edge fillet 44 are set to ellipse, and the aspect ratio of the ellipse of the first trailing edge fillet 24 and the second trailing edge fillet 44 is set to 6.

[0023] The long blade 2 is provided with a leading edge 21 near the middle of the impeller body 1, and a first leading edge fillet 23 is provided at the end of the leading edge 21.

[0024] The short blade 4 is provided with a leading edge 41 near the middle of the impeller body 1, and a second leading edge fillet 43 is provided at the end of the leading edge 41.

[0025] The first leading edge fillet 23 and the second leading edge fillet 43 are both set to elliptical shapes, and the aspect ratio of the ellipse of the first leading edge fillet 23 and the second leading edge fillet 43 is set to 5.

[0026] When the gas medium flows through the surfaces of the long blade 2 and the short blade 4, the boundary layer will separate near the trailing edge 22 of the long blade and the trailing edge 42 of the short blade due to the adverse pressure gradient and viscosity. The trailing edge 22 of the long blade and the trailing edge 42 of the short blade, which are designed with a first trailing edge fillet 24 and a second trailing edge fillet 44, reduce flow separation and wake width, thereby reducing wake loss.

[0027] Common measures to reduce wake loss include: 1) blade surface treatment to control roughness; 2) aerodynamic optimization of blade profile to reduce the adverse pressure gradient; and 3) adjusting blade placement angle and consistency to improve wake loss.

[0028] This invention optimizes the structural design of the trailing edge 22 of the long blade and the trailing edge 42 of the short blade, thereby reducing the separation zone at the tail of the long blade 2 and the short blade 4. Numerical simulation calculations show that this structure effectively reduces wake loss and improves aerodynamic efficiency by 0.5% to 1%.

[0029] In addition to this embodiment, the structure of the first trailing edge fillet 24 and the second trailing edge fillet 44 can also be applied to the blade tails of closed impellers, semi-open impellers, and open impellers, and can also be applied to the blade tails of impellers in various application scenarios such as various compressors, expanders, and water pumps, with wide applications.

[0030] For those skilled in the art, any changes, modifications, substitutions, and variations made to the embodiments based on the teachings of this utility model, without departing from the principles and spirit of this utility model, still fall within the protection scope of this utility model.

Claims

1. A three-dimensional flow impeller comprising an impeller body (1), characterized in that: The outer surface of the impeller body (1) has a ring array of multiple long blades (2) and short blades (4) arranged at intervals. The long blades (2) and short blades (4) are arranged in an alternating manner. The long blades (2) are provided with a long blade trailing edge (22) near the outer edge of the impeller body (1). The end of the long blade trailing edge (22) is provided with a first trailing edge rounded corner (24). The short blades (4) are provided with a short blade trailing edge (42) near the outer edge of the impeller body (1). The end of the short blade trailing edge (42) is provided with a second trailing edge rounded corner (44).

2. A three-dimensional flow impeller according to claim 1, characterized in that: The length of the long blade (2) is longer than the length of the short blade (4).

3. A three-dimensional flow impeller according to claim 2, characterized in that: The first trailing edge fillet (24) and the second trailing edge fillet (44) are set to ellipse, and the aspect ratio of the ellipse of the first trailing edge fillet (24) and the second trailing edge fillet (44) is set to 4-6.

4. A three-dimensional flow impeller according to claim 3, wherein: The long blade (2) is provided with a leading edge (21) near the middle of the impeller body (1), and a first leading edge rounded corner (23) is provided at the end of the leading edge (21).

5. A three-dimensional flow impeller according to claim 4, wherein: The short blade (4) has a leading edge (41) near the middle of the impeller body (1), and a second leading edge fillet (43) is provided at the end of the leading edge (41).

6. A three-dimensional flow impeller according to claim 5, characterized in that: The first leading edge fillet (23) and the second leading edge fillet (43) are both set to elliptical shapes, and the aspect ratio of the ellipse of the first leading edge fillet (23) and the second leading edge fillet (43) is set to 3-5.

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