Impeller and manufacturing process thereof

Abstract

The invention relates to an impeller and belongs to the technical field of impeller production, the impeller comprises a front disc and a rear disc, a plurality of grooves are formed in the face, facing the rear disc, of the front disc, a plurality of blades are arranged on the side, facing the front disc, of the rear disc, the blades correspond to the grooves in a one-to-one mode, and the sides, away from the rear disc, of the blades are inserted into the corresponding grooves; the blades are made of materials capable of absorbing laser energy strongly, the front disc, the rear disc and the blades are made of plastics, and the surfaces, making contact with the grooves, of the blades are welded to the front disc through laser. The impeller has the effects that the production efficiency of the impeller is improved, the coaxiality and the connection strength of the front disc and the rear disc are improved, and the production quality of the impeller is improved.

Description

Technical Field

[0001] The present application relates to the technical field of impeller production, and in particular to an impeller and a manufacturing process thereof. Background Art

[0002] In view of the technical difficulties in manufacturing the complete impeller mold, the impeller is split into the front disc and the rear disc and molded separately. This mold opening technology is simple, and the front disc and the rear disc only need to be combined together by laser welding technology to form an integral impeller. This bonding technology used to be combined by ultrasound or glue. There will be a harsh noise during ultrasonic welding, and the operator's long-term operation will damage the hearing. In addition, ultrasonic welding combines two plastic workpieces by high-frequency vibration friction and heat generation. This vibration frequency will make the plastic workpieces very easy to crack during welding, affecting the quality and not conducive to later mass production. The bonding process of glue is not ideal. First of all, glue is a consumable material, which will increase the cost. Secondly, glue will increase the weight of the product. In addition, glue needs curing time. Seriously affect production efficiency. In addition, during the docking process of the existing front disc and rear disc, the coaxiality of the front disc and the rear disc must be ensured first. This not only requires the production equipment to have precise positioning and fixing devices, but also the high-frequency vibration of the front disc and the rear disc during the ultrasonic welding process will lead to inaccurate coaxiality, affecting product quality. Summary of the invention

[0003] In order to improve the production efficiency of the impeller, improve the coaxiality and connection strength of the front disk and the rear disk, and improve the production quality of the impeller, the present application provides an impeller and a manufacturing process thereof.

[0004] The impeller provided in this application adopts the following technical solution: An impeller comprises a front disk and a rear disk, wherein a plurality of grooves are formed on a surface of the front disk facing the rear disk, and a plurality of blades are provided on a side of the rear disk facing the front disk, wherein the blades correspond to the grooves one by one, and the blades are inserted into the corresponding grooves on the side away from the rear disk. The front disk is made of a light-transmitting material, and the blades are made of a material that can absorb laser energy strongly. The materials used for the front disk, the rear disk and the blades are all plastic, and the surfaces of the blades in contact with the grooves are laser welded to the front disk.

[0005] By adopting the above technical solution, the blades are inserted into the corresponding grooves to ensure the coaxiality of the front disc and the rear disc. There is no need to install precise positioning devices and fixing devices on the production equipment, which has low requirements on the production equipment and is convenient for processing. The groove provides a concave surface, which can effectively increase the welding area, thereby improving the strength and stability of the welding. This design also avoids the stress concentration problem of welding only on the surface of the blade facing the front disk, reduces the stress concentration of the welding point, and ensures the uniformity and strength of the welding point; In addition, welding is concentrated in the groove, and the laser energy will not be excessively dispersed, which is conducive to concentrated melting of specific areas, thereby reducing the overall thermal deformation of the impeller and ensuring the accuracy and quality of the structure; Laser welding is characterized by precision and concentration. Since the contact surface between the blade and the groove is relatively small, laser welding can complete high-strength welding in a very localized area, which reduces the heating time of the entire impeller and avoids material deformation or damage caused by overheating; The blades are tightly combined with the front disc through the grooves, and the structure remains consistent after welding, which reduces the disturbance of the airflow when the impeller rotates and improves the aerodynamic performance. In this way, the impeller can promote air flow more effectively and improve the overall work efficiency; At the same time, the use of laser welding can improve the connection strength between the impeller and the front disc, and the tensile force can be greater than 200N.

[0006] In summary, the welding surface design of the blade and the groove provides the dual advantages of precise positioning and enhanced strength. It not only improves the manufacturing accuracy of the impeller, but also effectively reduces the thermal deformation and stress concentration that may occur during the welding process. The groove design ensures the stability of the blade during welding, and during the laser welding process, the laser energy can be concentrated on a specific part to form a strong weld, thereby improving the overall durability and performance of the impeller. At the same time, this combination of blade and groove design not only optimizes the mechanical properties of the structure, but also adapts to the special requirements of the laser welding process, making the manufacturing process more efficient and stable.

[0007] Optionally, the material of the front plate is polycarbonate / polypropylene / polymethyl methacrylate.

[0008] By adopting the above technical solutions, these materials are usually transparent or translucent, and the laser can pass through these materials to complete welding. Moreover, these materials have good strength and toughness and can withstand certain mechanical stresses and environmental changes. At the same time, these materials are also heat-resistant and remain stable within a certain temperature range to adapt to the temperature rise generated when the impeller is working.

[0009] Optionally, the material used for the rear disc is glass fiber reinforced nylon / polyamide / polyphenylene sulfide.

[0010] By adopting the above technical solutions, these materials can effectively absorb laser energy and promote the effect of laser welding due to their dark color. In addition, these materials have excellent strength, heat resistance and chemical resistance, and are suitable for long-term work in high stress and high temperature environments. At the same time, these engineering plastic materials are relatively cost-effective and suitable for mass production applications.

[0011] Optionally, the side of the front disc facing the rear disc gradually sinks inward toward the center axis of the two discs, the depth of each part of the groove remains the same, and the height of the blade at one end close to the center axis of the rear disc is greater than the height of the blade at one end away from the center axis of the rear disc.

[0012] By adopting the above technical solution, the concave design of the front and rear discs helps to optimize the airflow guidance effect. When the impeller rotates, the concave disc surface can effectively guide the airflow to flow in a specific direction and reduce the turbulence and eddy current of the airflow on the disc surface. Such a design can reduce aerodynamic resistance and improve the working efficiency of the impeller; The concave design helps to improve the overall strength of the impeller. The concave front and rear discs not only make the disc surface more structural, but also better disperse the stress during rotation and reduce the deformation or distortion of the impeller. Especially at high speeds, the concave disc design can effectively counteract the influence of centrifugal force and other external forces, extending the service life of the impeller; Compared with the flat design, the concave disk design can improve the structural rigidity without increasing the thickness or additional materials, and can even reduce the material usage while maintaining the structural strength, thus reducing the overall weight of the impeller. This plays an important role in the energy saving and efficient operation of the equipment; The concave design of the front and rear discs can balance the force on the impeller during rotation. Due to the certain shape differences of the disc surface, the concave design can reduce the unbalanced aerodynamic load generated during rotation, further reduce the vibration of the impeller, and improve the dynamic balance performance. This can ensure that the equipment runs more smoothly and efficiently, and reduce mechanical wear; The concave design of the front and rear discs increases the surface area of ​​the discs, which is beneficial for heat dissipation when the impeller is working at high temperature or high load. By increasing the surface area, the concave part can help dissipate heat and improve the durability and performance stability of the equipment in high temperature working environment.

[0013] Taller blades are subject to greater bending forces near the center axis. By increasing the height, the stress can be dispersed, reducing mechanical fatigue caused by rotation, thereby extending the service life of the blades. The lower end away from the center axis means less material is used, thus reducing the overall weight of the impeller. This design not only reduces material costs, but also improves the system's response speed and energy efficiency, especially in high-speed rotation applications.

[0014] Optionally, a surface of the blade facing the front disk is a curved surface and fits against an inner bottom wall of the groove.

[0015] Optionally, a distance is left between one end of the blade away from the central axis of the rear disk and the outer circumferential surface of the disk.

[0016] By adopting the above technical solution, this design can help to evenly distribute the airflow. When the fluid passes through the blades, the airflow near the outer side of the disc will naturally diffuse, avoiding fluid blockage or poor flow caused by direct connection between the blades and the outer surface. Leaving a gap can reduce the impact of the boundary layer effect on the fluid movement and reduce the energy loss caused by the wall effect; In some impeller designs, if the blades are completely closed to the outer surface, turbulence and pressure accumulation may occur at the edge, affecting the efficiency and stability of the impeller. The spacing design allows the airflow to expand naturally from the tip of the blade, preventing turbulence from accumulating on the outer wall of the impeller, reducing vibration and noise; When the impeller is running at high speed, the rigid connection between the blade and the outer surface may cause greater stress concentration, resulting in wear or fatigue of the blade or outer surface. Retaining the spacing can reduce the stress concentration problem on the structure and extend the service life of the blade and disc.

[0017] Optionally, the blades are equidistantly distributed around the central axis of the rear disc, and the side surfaces of the blades are configured as outer arc surfaces and inner arc surfaces, and the extended arc lines of the outer arc surfaces of the blades gradually converge toward the center of the rear disc.

[0018] By adopting the above technical solution, the blades are designed around the central axis so that the fluid can be evenly guided in the direction of rotation, which helps to convert kinetic energy into efficient axial or centrifugal flow. By guiding the fluid along the central axis, the blades can accelerate the flow of the fluid. This axial flow design reduces the generation of lateral airflow, thereby improving the overall flow efficiency of the impeller.

[0019] Optionally, the curvature of the inner curved surface of the blade is smaller than the curvature of the outer curved surface of the blade.

[0020] By adopting the above technical solution, the difference in curvature helps to control the flow rate of the fluid. The side with a larger curvature helps to accelerate the fluid, while the side with a smaller curvature controls the fluid so that it does not generate excessive pressure gradients when flowing through. This shape makes the flow of fluid in the impeller smoother and reduces unstable airflow. In addition, the fluid can flow smoothly from one end of the impeller to the other, while reducing energy loss. This design with uneven curvature usually enables the impeller to maintain a higher fluid kinetic energy transfer efficiency at high speeds. At the same time, the asymmetric blade design can reduce the turbulence of the fluid when it flows through the blade surface, reduce noise generation, and improve the stability of the impeller.

[0021] Optionally, the ventilation opening of the front disk is provided with a first circular protrusion, and the ventilation opening of the rear disk is provided with a second circular protrusion, the diameter of the protruding end of the first circular protrusion is smaller than the diameter of the recessed end of the first circular protrusion, and the diameter of the protruding end of the second circular protrusion is the same as the diameter of the recessed end of the second circular protrusion.

[0022] By adopting the above technical solution, the shape of the first circular protrusion is similar to a nozzle, which will play a role in accelerating the airflow. When the gas passes through a narrow area, the airflow speed will increase, thereby forming a higher dynamic pressure during the impeller intake and exhaust process. This design can effectively increase the speed of the airflow, making the impeller's air intake efficiency or air outlet efficiency higher, thereby improving the overall performance of the equipment. The second circular protrusion facilitates the connection between the rear disc and the components.

[0023] The present application also provides an impeller manufacturing process using the following technical solution: An impeller manufacturing process, used to manufacture the above-mentioned impeller, comprises the following steps: The front plate and the rear plate are molded separately, and the front plate and the rear plate are cast separately; Insert the blades into the corresponding grooves; Press the front and rear discs tightly; A laser with a fixed wavelength is selected and the laser is directed onto the contact surface between the blade and the groove to weld the blade to the front disk.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: 1. By using laser welding, high-strength welding can be completed in a very local area, which reduces the heating time of the entire impeller, avoids material deformation or damage caused by excessive heating, improves the connection strength between the impeller and the front disc, and the pull-out force can be greater than 200N; 2. The welding surface design of the blade and groove provides the dual advantages of precise positioning and enhanced strength. It not only improves the manufacturing accuracy of the impeller, but also effectively reduces the thermal deformation and stress concentration that may occur during the welding process. The groove design ensures the stability of the blade during welding, and during the laser welding process, it can concentrate the laser energy on a specific part to form a strong weld, thereby improving the overall durability and performance of the impeller. At the same time, this combination of blade and groove design not only optimizes the mechanical properties of the structure, but also adapts to the special requirements of the laser welding process, making the manufacturing process more efficient and stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application.

[0026] Figure 2It is a schematic diagram of the structure of the first outer surface and the first annular protrusion according to an embodiment of the present application.

[0027] Figure 3 It is a schematic structural diagram of an embodiment of the present application for reflecting the second inner surface, the second annular protrusion and the impeller.

[0028] Explanation of the reference numerals: 1. front disc; 11. first inner surface; 12. first outer surface; 13. first annular protrusion; 14. groove; 2. rear disc; 21. second inner surface; 22. second outer surface; 23. second annular protrusion; 3. blade. DETAILED DESCRIPTION

[0029] The following is combined with Figure 1-3 This application is described in further detail.

[0030] An embodiment of the present application discloses an impeller.

[0031] like Figure 1 , Figure 2 and Figure 3 , the impeller includes a front disc 1 and a rear disc 2; The side of the front disc 1 facing the rear disc 2 is defined as a first inner surface 11, the side of the front disc 1 away from the rear disc 2 is defined as a first outer surface 12, the side of the rear disc 2 facing the front disc 1 is defined as a second inner surface 21, and the side of the rear disc 2 away from the front disc 1 is defined as a second outer surface 22.

[0032] The first inner surface 11 is an annular arc surface that is concave toward the central axis and away from the rear disc 2, and the first outer surface 12 is an annular arc surface that is convex toward the central axis and away from the rear disc 2. The slopes of the first outer surface 12 and the first inner surface 11 gradually decrease toward the central axis, that is, the curvature of the first outer surface 12 and the first inner surface 11 in the direction close to the central axis gradually becomes gentle.

[0033] The front disc 1 is integrally formed with a first annular protrusion 13, and the front disc 1 of the first annular protrusion 13 is coaxially arranged, the outer circumferential surface of the first annular protrusion 13 is connected with the first outer surface 12, and the inner circumferential surface of the first annular protrusion 13 is connected with the first inner surface 11. The arc surface of the outer circumferential surface of the first annular protrusion 13, and the slopes of the outer circumferential surface and the inner circumferential surface of the first annular protrusion 13 gradually increase in the direction away from the rear disc 2, thereby forming a diameter of the protruding end of the first annular protrusion 13 smaller than the diameter of the concave end of the first annular protrusion 13.

[0034] The first inner surface 11 and the inner surface of the first annular protrusion 13 are jointly provided with a plurality of grooves 14, the depth of the grooves 14 is 3 mm, the depth of each part of the grooves 14 remains the same, the plurality of grooves 14 are equidistantly arranged along the circumference of the front disc 1, the inner side walls on both sides of the grooves 14 are both arc-shaped side surfaces, the two inner side walls of the grooves 14 have the same bending direction, and the curvature of the inner side wall of one groove 14 is smaller than the curvature of the other inner side wall of the groove 14.

[0035] The width of the groove 14 at one end close to the outer circumference of the front disk 1 is smaller than the width of the groove 14 at one end away from the outer circumference of the front disk 1. The end of the groove 14 close to the outer circumference of the front disk 1 is spaced apart from the outer circumference of the front disk 1, and the extended arc line of the large-arc arc-shaped side surface of the groove 14 gradually converges toward the center of the front disk 1.

[0036] The second inner surface 21 is an annular arc surface that protrudes toward the central axis and toward the front disc 1, and the second outer surface 22 is an annular arc surface that is recessed toward the central axis and toward the front disc 1. The slopes of the second outer surface 22 and the second inner surface 21 gradually decrease toward the central axis, that is, the curvature of the second outer surface 22 and the second inner surface 21 in the direction close to the central axis gradually becomes gentler.

[0037] The rear disc 2 is integrally formed with a second annular protrusion 23, and the rear disc 2 is coaxially arranged with the second annular protrusion 23. The outer circumferential surface of the second annular protrusion 23 is connected with the second inner surface 21, and the inner circumferential surface of the second annular protrusion 23 is connected with the second outer surface 22. The arc surface of the outer circumferential surface of the second annular protrusion 23, the slope of the outer circumferential surface of the second annular protrusion 23 and the slope of the inner circumferential surface of the second annular protrusion 23 gradually decrease toward the direction approaching the central axis of the rear disc 2, and the diameter of the protruding end of the second annular protrusion 23 is equal to the diameter of the recessed end of the second annular protrusion 23.

[0038] The second outer surface 22 is integrally formed with a plurality of blades 3, and the blades 3 correspond to the grooves 14 one by one and fit into the grooves 14. The height of the end of the blade 3 close to the central axis of the rear disk 2 is greater than the height of the end of the blade 3 away from the central axis of the rear disk 2. The side of the blade 3 facing the front disk 1 is an arc surface and fits with the inner bottom wall of the groove 14. There is a gap between the end of the blade 3 away from the central axis of the rear disk 2 and the outer peripheral surface of the rear disk 2. The blades 3 are equidistantly distributed around the central axis of the rear disk 2, and the side surfaces of the blade 3 are set as outer arc surfaces and inner arc surfaces. The extended arc of the outer arc surface of the blade 3 gradually converges toward the center of the rear disk 2, and the curvature of the inner arc surface of the blade 3 is smaller than the curvature of the outer arc surface of the blade 3.

[0039] The materials used for the front disk 1, the rear disk 2 and the blades 3 are plastic, and the materials of the rear disk 2 and the blades 3 are the same. The material used for the front disk 1 can be polycarbonate / polypropylene / polymethyl methacrylate, and the material used for the rear disk 2 and the blades 3 can be glass fiber reinforced nylon / polyamide / polyphenylene sulfide.

[0040] Since the materials used for the front disk 1 are usually transparent or translucent, the laser can penetrate these materials to complete welding. Moreover, these materials have good strength and toughness and can withstand certain mechanical stresses and environmental changes. At the same time, these materials are also heat-resistant and remain stable within a certain temperature range to adapt to the temperature rise generated when the impeller is working.

[0041] The material used for the rear plate 2 is dark in color, which can effectively absorb laser energy and promote the effect of laser welding. In addition, these materials have excellent strength, heat resistance and chemical resistance, and are suitable for long-term work in high stress and high temperature environments. At the same time, these engineering plastic materials have a relatively reasonable cost and are suitable for mass production applications.

[0042] Therefore, the surface of the blade 3 in contact with the groove 14 can be laser welded to the front disk 1 .

[0043] When connecting the front disk 1 and the rear disk 2, the blades 3 are inserted into the corresponding grooves 14 to ensure the coaxiality of the front disk 1 and the rear disk 2. There is no need to install precise positioning devices and fixing devices on the production equipment, which has low requirements on the production equipment and is convenient for processing. The groove 14 provides a concave surface, which can effectively increase the welding area, thereby improving the strength and stability of the welding. This design also avoids the stress concentration problem of the blade 3 being welded only on the surface facing the front disk 1, reduces the stress concentration at the welding point, and ensures the uniformity and strength of the welding point; Furthermore, the welding is concentrated in the groove 14, and the laser energy will not be excessively dispersed, which is conducive to concentrated melting of a specific area, thereby reducing the thermal deformation of the impeller as a whole and ensuring the accuracy and quality of the structure; Laser welding is characterized by precision and concentration. Since the contact surface between the blade 3 and the groove 14 is relatively small, laser welding can complete high-strength welding in a very localized area, which reduces the heating time of the entire impeller and avoids deformation or damage of the material due to overheating; The blade 3 is tightly connected to the front disc 1 through the groove 14, and the structure after welding remains consistent, which reduces the disturbance of the airflow when the impeller rotates and improves the aerodynamic performance. In this way, the impeller can more effectively promote the air flow and improve the overall work efficiency; At the same time, the laser welding method can improve the connection strength between the impeller and the front disk 1, and the tensile force can be greater than 200N.

[0044] The concave design of the front disc 1 and the rear disc 2 helps to optimize the airflow guidance effect. When the impeller rotates, the concave disc surface can effectively guide the airflow to flow in a specific direction and reduce the turbulence and eddy current of the airflow on the disc surface. Such a design can reduce aerodynamic resistance and improve the working efficiency of the impeller; The concave design helps to improve the overall strength of the impeller. The concave of the front disc 1 and the rear disc 2 not only makes the disc surface more structural, but also can better disperse the stress during the rotation process and reduce the deformation or distortion of the impeller. Especially under high-speed operation, the concave disc design can effectively counteract the influence of centrifugal force and other external forces, and extend the service life of the impeller.

[0045] The design of leaving a gap between the end of the blade 3 away from the central axis of the rear disc 2 and the outer peripheral surface of the disc can help evenly distribute the airflow. When the fluid passes through the blade 3, the airflow near the outer side of the disc will naturally diffuse, avoiding fluid blockage or poor flow caused by direct connection between the blade 3 and the outer peripheral surface. Leaving a gap can reduce the impact of the boundary layer effect on the fluid movement and reduce the energy loss caused by the wall effect.

[0046] The blades 3 are designed around the central axis so that the fluid can be evenly guided in the direction of rotation, which helps to convert kinetic energy into efficient axial or centrifugal flow. By guiding the fluid along the central axis, the blades 3 can accelerate the flow of the fluid. This axial flow design reduces the generation of lateral airflow, thereby improving the overall flow efficiency of the impeller.

[0047] The first annular protrusion 13 is similar in shape to a nozzle and plays a role in accelerating the airflow. When the gas passes through a narrow area, the airflow velocity increases, thereby forming a higher dynamic pressure during the impeller intake and exhaust process. This design can effectively increase the airflow velocity, making the impeller's air intake efficiency or air outlet efficiency higher, thereby improving the overall performance of the device.

[0048] The implementation principle of the embodiment of the present application is as follows: the front disk 1 is made of a material with good light transmittance, while the rear disk 2 and the blades 3 are made of a material that absorbs laser energy strongly, and the blades 3 and the grooves 14 are matched to realize the production of the impeller through the laser welding process. The welding surface design of the blades 3 and the grooves 14 provides the dual advantages of precise positioning and enhanced strength. It not only improves the manufacturing accuracy of the impeller, but also effectively reduces the thermal deformation and stress concentration that may occur during the welding process. The groove 14 design ensures the stability of the blade 3 during welding, and during the laser welding process, the laser energy can be concentrated on a specific part to form a strong weld, thereby improving the overall durability and performance of the impeller. At the same time, the combination of the blade 3 and the groove 14 design not only optimizes the mechanical properties of the structure, but also adapts to the special requirements of the laser welding process, making the manufacturing process more efficient and stable.

[0049] The present application also provides an impeller manufacturing process for producing the impeller of the present application, comprising the following steps: The front plate 1 and the rear plate 2 are molded separately, and the front plate 1 and the rear plate 2 are cast separately; Insert the blade 3 into the corresponding groove 14; Press the front disc 1 and the rear disc 2 tightly; A laser with a fixed wavelength is selected and the laser is directed onto the contact surface of the blade 3 and the groove 14 , so that the blade 3 and the front disk 1 are welded.

[0050] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An impeller, characterized in that: The invention comprises a front disc (1) and a rear disc (2), wherein a plurality of grooves (14) are provided on a surface of the front disc (1) facing the rear disc (2), and a plurality of blades (3) are provided on a side of the rear disc (2) facing the front disc (1), wherein the blades (3) correspond to the grooves (14) one by one, and the side of the blades (3) away from the rear disc (2) is inserted into the corresponding grooves (14), wherein the front disc (1) is made of a light-transmitting material, and the blades (3) are made of a material that can absorb laser energy strongly, and the materials used for the front disc (1), the rear disc (2) and the blades (3) are all plastics, and the surfaces of the blades (3) in contact with the grooves (14) are laser welded to the front disc (1).

2. The impeller according to claim 1, characterized in that: The material used for the front plate (1) is polycarbonate / polypropylene / polymethyl methacrylate.

3. The impeller according to claim 1, characterized in that: The material used for the rear disc (2) and the blades (3) is glass fiber reinforced nylon / polyamide / polyphenylene sulfide.

4. The impeller according to claim 1, characterized in that: The front disc (1) is gradually recessed on one side facing the rear disc (2) in a direction close to the central axis of the two discs, the depth of each part of the groove (14) remains the same, and the height of the blade (3) at one end close to the central axis of the rear disc (2) is greater than the height of the blade (3) at one end away from the central axis of the rear disc (2).

5. The impeller according to claim 4, characterized in that: The surface of the blade (3) facing the front disk (1) is a curved surface and fits against the inner bottom wall of the groove (14).

6. The impeller according to claim 5, characterized in that: A distance is left between the end of the blade (3) away from the central axis of the rear disc (2) and the outer peripheral surface of the rear disc (2).

7. The impeller according to claim 1, characterized in that: The blades (3) are equidistantly distributed around the central axis of the rear disc (2), and the side surfaces of the blades (3) are arranged as outer arc surfaces and inner arc surfaces, and the extended arc lines of the outer arc surfaces of the blades (3) gradually converge toward the center of the rear disc (2).

8. The impeller according to claim 7, characterized in that: The curvature of the inner curved surface of the blade (3) is smaller than the curvature of the outer curved surface of the blade (3).

9. The impeller according to claim 7, characterized in that: The ventilation opening of the front disc (1) is provided with a first annular protrusion (13), and the ventilation opening of the rear disc (2) is provided with a second annular protrusion (23); the diameter of the protruding end of the first annular protrusion (13) is smaller than the diameter of the recessed end of the first annular protrusion (13), and the diameter of the protruding end of the second annular protrusion (23) is the same as the diameter of the recessed end of the second annular protrusion (23).

10. A process for manufacturing an impeller, characterized in that: The method for manufacturing the impeller according to any one of claims 1 to 9 comprises the following steps: The front plate (1) and the rear plate (2) are molded separately, and the front plate (1) and the rear plate (2) are cast separately; Inserting the blade (3) into the corresponding groove (14); Press the front plate (1) and the rear plate (2) tightly together; A laser with a fixed wavelength is selected and projected onto the contact surface of the blade (3) and the groove (14), so that the blade (3) and the front disc (1) are welded.

Images