Method for manufacturing an impeller of a propeller and impeller

Abstract

The present disclosure provides a manufacturing method of an impeller of a propeller and the impeller, and belongs to the field of ship propellers. The manufacturing method comprises the following steps: providing an integral structure, wherein the integral structure comprises a hub and a plurality of blades, the plurality of blades are uniformly and spacedly arranged along the outer periphery of the hub, and one end of each of the plurality of blades is connected with the outer periphery of the hub; sleeving an outer ring frame outside the plurality of blades, and coaxially arranging the outer ring frame with the hub; and welding the inner wall of the outer ring frame with the other end of each of the plurality of blades, thereby obtaining the impeller. The present disclosure can improve the machining precision of the impeller.

Description

Technical Field

[0001] This disclosure pertains to the field of marine propulsion, and particularly relates to a method for manufacturing a propulsion impeller and the impeller itself. Background Technology

[0002] The impeller is a crucial structure in a propulsion system. An impeller typically comprises an outer ring frame, multiple blades, and a hub. The outer ring frame is located outside the hub, and the multiple blades are situated between the outer ring frame and the hub, respectively connected to both the outer ring frame and the hub.

[0003] In related technologies, impellers are typically manufactured using a combination of casting and grinding. After casting and demolding to obtain the impeller blank, the impeller blank is then machined, such as by grinding, to ensure that all dimensions of the impeller meet the design requirements.

[0004] However, for larger impellers, casting is more difficult and the casting process is harder to control. Casting defects such as porosity and looseness are prone to occur at the connection between the blades and the outer ring frame, as well as between the blades and the hub, which affect the quality of the impeller and result in poor precision of the machined impeller. Summary of the Invention

[0005] This disclosure provides a method for manufacturing a propeller impeller and the impeller itself, which can improve the machining accuracy of the impeller and further enhance the propulsion efficiency of the propeller. The technical solution is as follows:

[0006] This disclosure provides a method for manufacturing an impeller, the method comprising: providing an integral structural component, the integral structural component including a hub and a plurality of blades, the plurality of blades being evenly spaced along the outer periphery of the hub, and one end of each plurality of blades being connected to the outer periphery of the hub; fitting an outer ring frame over the plurality of blades, and making the outer ring frame coaxial with the hub; and welding the inner wall of the outer ring frame to the other end of each plurality of blades to obtain the impeller.

[0007] In another implementation of this disclosure, the provision of the integral structural component includes: integrally forming a blank of the integral structural component, wherein the blank has a machining allowance of not less than 3 mm and a slag discharge area is provided at one end of the blank along the radial outward direction; machining the outer surface of the blank and removing the slag discharge area of ​​the blank to obtain the integral structural component.

[0008] In another implementation of this disclosure, the length of the slag discharge zone along the radial direction of the blade is not less than 15 mm.

[0009] In another implementation of this disclosure, the method further includes: rolling a metal plate into a ring structure and welding the butt joints of the metal plates together; machining the inner hole of the ring structure so that the inner hole matches the integral structural component.

[0010] In another implementation of this disclosure, after the outer ring frame is fitted over the plurality of blades, the manufacturing method further includes:

[0011] Adjust the axial position of the outer ring frame relative to the blades so that each of the plurality of blades is at the same distance from both ends of the outer ring frame.

[0012] In another implementation of this disclosure, the step of welding the inner wall of the outer ring frame to the plurality of blades to obtain the impeller includes: welding the middle part of the blade tip of each blade to the inner wall of the outer ring frame by laser welding process; and welding all the blade tips of the blades to the inner wall of the outer ring frame by argon arc welding.

[0013] In another implementation of this disclosure, after welding the inner wall of the outer ring frame to the plurality of blades, the manufacturing method further includes: performing precision machining on the outer surface of the blades, the inner wall of the outer ring frame, and the outer surface of the blades.

[0014] In another implementation of this disclosure, an impeller is also provided, which is manufactured by the manufacturing method described above. The impeller includes an integral structural component and an outer ring frame. The integral structural component includes multiple blades and a hub. The multiple blades are evenly connected to the outer body of the hub at intervals along the outer periphery. The outer ring frame is located outside the multiple blades and is coaxially arranged with the hub. The inner wall of the outer ring frame is welded to the multiple blades respectively.

[0015] In another implementation of this disclosure, the integral structural component is a copper alloy cast structural component.

[0016] In another implementation of this disclosure, the outer ring frame is a ring-shaped copper alloy structural component.

[0017] The beneficial effects of the technical solutions provided in this disclosure are:

[0018] Since the impeller's multiple blades and hub are machined as a single structural component, the connection strength between the blades and hub can be improved by using a single structural component. At the same time, it avoids machining the outer ring frame as a single piece, thus reducing the machining difficulty. It also avoids the impact on casting quality caused by abrupt changes in cross-section at the connection points between the outer ring frame and multiple blades during the single casting process, thereby improving the quality of the impeller.

[0019] Furthermore, machining the outer ring frame separately can effectively improve its internal quality. Moreover, connecting the integral structural component to the outer ring frame via welding fully preserves the advantages of each component and avoids the quality risks associated with integral casting. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the impeller structure provided in an embodiment of the present disclosure;

[0022] Figure 2 yes Figure 1 A schematic diagram of the axial section structure;

[0023] Figure 3 This is a flowchart illustrating a method for manufacturing a propeller impeller according to an embodiment of this disclosure;

[0024] Figure 4 This is a flowchart illustrating another method for manufacturing the impeller of a propeller provided in this embodiment of the present disclosure;

[0025] Figure 5 A schematic diagram of the blank of the integral structural component provided in the embodiments of this disclosure;

[0026] Figure 6 A schematic diagram of the integrated structural component provided in the embodiments of this disclosure;

[0027] Figure 7 for Figure 6 Axial section view;

[0028] Figure 8 This is a schematic diagram of the processing of the outer ring frame provided in an embodiment of this disclosure;

[0029] Figure 9 This is a schematic diagram of the assembly of the outer ring frame and the integrated structural component provided in an embodiment of this disclosure.

[0030] The symbols in the diagram represent the following meanings:

[0031] 100. Integrated structural components;

[0032] 101. Hub body;

[0033] 102. Blades; 1021. Slag discharge area;

[0034] 200. Outer ring frame;

[0035] 201. Butt joint. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0037] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” “top,” and “bottom,” etc., are used only to indicate relative positional relationships; when the absolute position of the described objects changes, the relative positional relationship may also change accordingly.

[0038] Figure 1 This is a schematic diagram of the impeller structure provided in an embodiment of the present disclosure, combined with... Figure 1 The impeller includes a hub 101, multiple blades 102, and an outer ring frame 200. The outer ring frame 200 is coaxially sleeved on the outside of the hub 101, and the multiple blades 102 are arranged at intervals along the circumference of the hub 101, and are all located between the hub 101 and the outer ring frame 200. Each blade 102 is connected to both the hub 101 and the outer ring frame 200.

[0039] The hub 101 mainly bears the weight of the impeller and supports the entire impeller structure, while also transmitting the thrust generated by the blades 102.

[0040] The blade 102 mainly generates thrust by rotating under the drive of the outer ring frame 200, and connects the hub 101 to the outer ring frame 200. The outer ring frame 200 is the part that integrates the drive motor rotor. The motor rotor and the outer ring frame 200 are assembled together to form a whole. The rotation of the rotor and the outer ring frame 200 drives the entire impeller to rotate.

[0041] The outer ring frame 200 is a circular frame structure.

[0042] The impeller is a major load-bearing component in an electric propulsion unit. During operation, its outer cylindrical chamber is subjected to alternating water pressure. Furthermore, when the impeller is running, the connection between the blades 102 and the outer ring frame 200 is also subjected to the thrust generated by the impeller. Therefore, the connections between the blades 102 and the hub 101, and between the blades 102 and the outer ring frame 200, are critical load-bearing areas in the impeller. The manufacturing of the blades 102 requires extremely high quality, and internal defects exceeding acceptable limits are not permitted. However, using the casting method described in related technologies to integrally machine the impeller is highly likely to introduce casting defects such as porosity and looseness at the connections between the blades and the outer ring frame, as well as between the blades and the hub, affecting the quality of the impeller and resulting in poor precision.

[0043] The impeller in this embodiment is a copper alloy structural component.

[0044] Figure 2 yes Figure 1 A schematic diagram of the axial section structure, combined with Figure 2 This disclosure provides a schematic diagram of the structure of an impeller for a propeller. The impeller includes an integral structural component 100 and an outer ring frame 200.

[0045] The integral structural component 100 includes multiple blades 102 and a hub 101. The multiple blades 102 are evenly arranged at intervals along the outer periphery of the hub 101, and one end of each blade 102 is connected to the outer periphery of the hub 101.

[0046] The outer ring frame 200 is fitted around the multiple blades 102 and is arranged coaxially with the hub 101. The inner wall of the outer ring frame 200 is welded to the multiple blades 102 respectively.

[0047] Since the multiple blades 102 and hub 101 of the impeller are machined as a single structural component, the connection strength between the blades 102 and hub 101 can be improved by using the single structural component 100. At the same time, it can avoid machining the outer ring frame 200 as a single component, thus reducing the machining difficulty. It can also avoid the impact on the casting quality caused by the abrupt change in cross-section at the connection between the outer ring frame 200 and the multiple blades 102 during the single casting process, thereby improving the quality of the impeller.

[0048] In addition, machining the outer ring frame 200 separately can effectively improve its internal quality. Furthermore, by welding the integral structural component 100 to the outer ring frame 200, the advantages of each component are fully preserved, and the quality risks associated with integral casting are avoided.

[0049] Optionally, the outer ring frame 200 is a copper alloy ring structure.

[0050] Setting the outer ring frame 200 as a copper alloy annular structure not only facilitates welding it together with multiple blades 102, but also, due to the high strength of the copper alloy structure, can greatly improve the structural strength of the impeller.

[0051] Optionally, the integral structural component 100 is a copper alloy cast structural component.

[0052] The integral structural component 100 is set as a copper alloy casting structural component, so that the integral structural component 100 can be formed in one piece by casting, simplifying the processing procedure, while ensuring that the integral structural component 100 has a large structural strength.

[0053] Optionally, the hub 101 is a hollow cylindrical structural component, and the length of the hub 101 in the axial direction is greater than the length of the outer ring frame 200 in the axial direction.

[0054] This allows the two ends of the hub 101 to protrude beyond the outer ring frame 200, so that the hub 101 can be connected to other components, thereby facilitating the installation of the impeller, etc.

[0055] On the other hand, this disclosure also provides a method for manufacturing an impeller, which can be used to manufacture... Figure 1 The impeller shown.

[0056] Figure 3 This is a flowchart illustrating a method for manufacturing a propeller impeller according to an embodiment of this disclosure, in conjunction with... Figure 3 The production method includes:

[0057] S301: Provides integrated structural components.

[0058] The structure of the integral structural component 100 is as described above, and will not be repeated here.

[0059] S302: The outer ring frame is fitted over multiple blades, and the outer ring frame is coaxial with the hub.

[0060] The structure of the outer ring frame 200 is as described above, and will not be repeated here.

[0061] S303: The inner wall of the outer ring frame is welded to the other end of multiple blades to obtain an impeller.

[0062] Since the multiple blades 102 and hub 101 of the impeller are machined as a single structural component, the connection strength between the blades 102 and hub 101 can be improved by using the single structural component 100. At the same time, it can avoid machining the outer ring frame 200 as a single component, thus reducing the machining difficulty. It can also avoid the impact on the casting quality caused by the abrupt change in cross-section at the connection between the outer ring frame 200 and the multiple blades 102 during the single casting process, thereby improving the quality of the impeller.

[0063] In addition, machining the outer ring frame 200 separately can effectively improve its internal quality. Furthermore, by welding the integral structural component 100 to the outer ring frame 200, the advantages of each component are fully preserved, and the quality risks associated with integral casting are avoided.

[0064] Figure 4 This is a flowchart illustrating another method for manufacturing the impeller of a propeller provided in this disclosure embodiment, as shown below. Figure 4 As shown. This disclosure also provides another method for manufacturing an impeller, which can be used to produce... Figure 1 The impeller shown. The manufacturing method includes:

[0065] S401: A blank part for integral molding of a structural component.

[0066] The blank part has a machining allowance of not less than 3mm.

[0067] The aforementioned allowance of no less than 3mm for the shape of the blank refers to the fact that, based on the three-dimensional model of the impeller, when casting the blank, the outer surface of the integral structural part is extended outward by no less than 3mm according to the dimensions of the theoretical three-dimensional model, so that the actual formed size of the integral structural part is no less than 3mm larger than the theoretical size.

[0068] The dimensions of the blank part are larger than the corresponding dimensions of the integrated structural part in the 3D model, and the difference between the dimensions of the blank part and the corresponding dimensions in the 3D model is not less than 3mm.

[0069] In this embodiment of the disclosure, the blank of the integral structural component can be directly cast in one piece by casting.

[0070] In other words, casting is used to directly process the blank of an integral structural component including multiple blades and a hub. This not only improves the overall structural strength of the integral structural component, but also reduces the processing steps for multiple blades and a hub.

[0071] The blank part has a machining allowance of not less than 3mm, which allows for the subsequent precision machining of the impeller.

[0072] The machining allowance on the outer surface of the blank is not less than 3mm. This allowance is sufficient to ensure that the blades and hub can offset the effects of deformation during subsequent machining.

[0073] Figure 5 This is a schematic diagram of the blank of the integrated structural component provided in the embodiments of this disclosure, combined with... Figure 5 The blank has a slag discharge area 1021 at the radially outward end.

[0074] During the casting process, impurities accumulate along the edges of the blades. After the casting cools, these impurities solidify and remain in the blade's edge region. This solidified impurity inevitably affects the blade's quality, causing internal quality defects at the outermost edge. To address this, a slag removal zone 1021 is established at the radially outward end of the blank. This slag removal zone helps to collect impurities from the casting process, improving the quality of the blade's edge and ultimately enhancing the quality of each blade in the integrally formed part, ensuring that each blade meets processing requirements.

[0075] Optionally, along the radial direction of the blade 102, the length of the slag discharge zone 1021 (i.e., Figure 5 d) in the figure is not less than 15mm.

[0076] In this embodiment, along the radial direction of the blade, the length of the slag discharge zone (i.e., Figure 5 In the figure, d) is 20mm.

[0077] Along the radial direction of the blade, the length of the slag discharge zone 1021 (that is...) Figure 5 The d) in the formula should not be less than 15mm. This ensures that the outermost edge of the blade also meets the processing requirements and that impurities will not be concentrated during the casting process, thereby improving the quality of the blade.

[0078] That is, during the casting process, the blade 102 needs to be extended outward by 20mm in the radial direction as the slag discharge zone 1021.

[0079] S402: The outer surface of the blank is machined and the slag discharge area of ​​the blank is removed to obtain an integral structural part.

[0080] Since the slag discharge zone is designed to remove impurities during molding, it can be removed directly by machining after molding.

[0081] By machining the outer surface of the blank and removing the slag removal area, the actual dimensions of the blank can meet the theoretical requirements in the three-dimensional model.

[0082] Figure 6 This is a schematic diagram of the integrated structural component provided in an embodiment of the present disclosure. Figure 7 for Figure 6 The axial section view, combined with Figure 6 and Figure 7 Through machining, the slag removal area of ​​the blank is first milled off, and then the outer surface of the blank is semi-finished to obtain an integral structural part.

[0083] S403: Roll metal sheets into a ring structure and weld the butt joints of the metal sheets together.

[0084] Figure 8 This is a schematic diagram of the processing of the outer ring frame provided in the embodiments of this disclosure, combined with... Figure 8 In this embodiment of the disclosure, the copper alloy steel plate is rolled into a ring structure according to the outer dimensions of the outer ring frame, and the butt joint 201 is welded by welding process to make it a complete ring structure.

[0085] S404: The inner hole of the ring structure is machined to match the integral structural component.

[0086] After the outer ring is formed, the inner hole of the ring structure is machined to make the inner hole size of the ring structure match the size of the blade tip.

[0087] The so-called mating dimension refers to a hole-shaft relationship set in mechanical design to meet specific functional requirements.

[0088] There are three common types of fit dimensions: clearance fit, interference fit, and transition fit. A clearance fit ensures there is always a gap between the hole and the shaft, requiring the hole to be larger than the shaft, and the minimum clearance must be greater than or equal to zero.

[0089] Interference fit: There is a certain interference between the hole and the shaft, and a certain external force is required to achieve relative movement.

[0090] Transition fit: The fit between the hole and the shaft may have interference or clearance, but the amount is not very large.

[0091] In this embodiment, the outer ring frame and the blade are designed with corresponding fit dimensions according to the clearance fit.

[0092] Combination Figure 8 Through machining, the inner hole of the ring structure is ground to ensure that the size and roughness of the inner hole meet the machining requirements.

[0093] S405: The outer ring frame is fitted over multiple blades, and the outer ring frame is coaxial with the hub.

[0094] Figure 9 This is a schematic diagram of the assembly of the outer ring frame and the integrated structural component provided in the embodiments of this disclosure, combined with... Figure 9 The tip of each blade 102 is fitted with the wall of the inner hole of the outer ring frame 200.

[0095] S406: Adjust the axial position of the outer ring frame relative to the blades so that each blade is at the same distance from both ends of the outer ring frame.

[0096] By adjusting the axial position of the outer ring frame relative to the blades, the distance between each blade and both ends of the outer ring frame can be made the same along the axial direction of the outer ring frame, ensuring that each blade is located at the center of the outer ring frame.

[0097] S407: The inner wall of the outer ring frame is welded together with multiple blades to obtain an impeller.

[0098] Optionally, step S407 can be implemented as follows:

[0099] 4071: The middle part of the blade tip is welded to the inner wall of the outer ring frame using laser welding technology.

[0100] First, laser welding is used to weld and fix the middle part of the blade tip to the inner hole of the outer ring frame. This ensures the accuracy of the blade's positioning with the inner hole of the outer ring frame and reduces the impact of conventional welding deformation on its positional accuracy.

[0101] 4072: Argon arc welding is used to weld the entire blade tip to the inner wall of the outer ring frame.

[0102] Then, argon arc welding is used to completely fix the blade tip to the inner hole of the outer ring frame, making the entire impeller a whole.

[0103] By adopting a laser combined with argon arc welding process, we can ensure the accuracy of the blade position and the outer ring frame, as well as the complete fusion of the blade tip with the outer ring frame, thus guaranteeing the structural strength requirements of the entire part.

[0104] At the same time, this combined process avoids defects inside the weld, which can effectively ensure the final internal quality of the impeller.

[0105] The welding material is stainless steel with a diameter of no more than 3 mm. In this embodiment, the welding material is GFS-316L stainless steel with a diameter of Φ2 mm.

[0106] S408: Stress-relief annealing of the impeller.

[0107] The impeller obtained through welding will have accumulated stress inside. This process can largely eliminate most of the thermal stress generated during the welding process, thus providing a basic guarantee for the stability of subsequent machining dimensions.

[0108] The so-called stress-relief annealing process involves placing parts into a heat treatment furnace, slowly heating the furnace to a specified temperature and holding it at that temperature for a period of time, and then slowly cooling it to improve the overall residual stress level of the parts.

[0109] In this embodiment, S408 can be implemented in the following manner:

[0110] (1) Place the impeller in a heat treatment furnace.

[0111] (2) Heat the heat treatment furnace to 500-600℃ within 1.5 hours and keep it at that temperature for at least 2 hours.

[0112] (3) After removing the impeller from the heat treatment furnace, place it in the air to cool naturally.

[0113] This process essentially eliminates most of the thermal stress on the impeller during welding, providing a basic guarantee for dimensional stability in subsequent machining.

[0114] S409: Perform flaw detection on the welds of the impeller after stress-relief annealing.

[0115] After the weld between the blade and the outer ring frame is completed, the machine shop will mill the root weld to expose the copper alloy weld, which will have a metallic luster and be subjected to 100% PT (Penetrant Testing).

[0116] This ensures that all welds are operable and accessible, while also guaranteeing weld quality.

[0117] S410: Finish the outer surface of the impeller.

[0118] The outer surface of the impeller includes the outer surface of the blades, the inner wall of the outer ring frame, and the outer surface of the outer ring frame.

[0119] By precision machining the outer surface of the blades, the inner wall of the outer ring frame, and the outer surface of the outer ring frame, the impeller can be finally shaped and obtained, so that the impeller meets the manufacturing precision requirements.

[0120] Furthermore, during the finishing process, the positioning stops of the impeller and other components are also finished according to the drawing requirements, so that the blades can be assembled into the propeller.

[0121] The above manufacturing method avoids many disadvantages of integral casting by assembling the impeller and simplifies the manufacturing process of the parts. This forming method not only gives full play to the advantages of the casting process, but also avoids the defect risks of integral casting and the cost cycle risks of forging. It controls risks and costs while effectively ensuring the quality characteristics of the impeller.

[0122] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A method for manufacturing an impeller for a propeller, characterized in that, The manufacturing method includes: A blank part for integrally forming an integral structural component is formed. The blank part has a machining allowance of not less than 3mm in its outer shape, and a slag discharge area is provided at one end of the blank part along the radial outward direction. The outer surface of the blank part is machined, and the slag discharge area of ​​the blank part is removed to obtain the integral structural component. The integral structural component includes a hub body and multiple blades. The multiple blades are evenly spaced along the outer periphery of the hub body, and one end of each of the multiple blades is connected to the outer periphery of the hub body. The outer ring frame is fitted over the multiple blades and is made coaxial with the hub body; The blade tips of each blade are welded to the inner wall of the outer ring frame using laser welding, and the blade tips are then welded to the inner wall of the outer ring frame using argon arc welding to obtain the impeller.

2. The manufacturing method according to claim 1, characterized in that, Along the radial direction of the blade, the length of the slag discharge zone is not less than 15 mm.

3. The manufacturing method according to claim 1, characterized in that, The method further includes: The metal plates are rolled into a ring structure, and the butt joints of the metal plates are welded together; The inner hole of the ring structure is machined to match the integral structural component.

4. The manufacturing method according to claim 1, characterized in that, After the outer ring frame is fitted over the plurality of blades, the manufacturing method further includes: Adjust the axial position of the outer ring frame relative to the blades so that each of the plurality of blades is at the same distance from both ends of the outer ring frame.

5. The manufacturing method according to claim 1, characterized in that, After welding the inner wall of the outer ring frame to the plurality of blades, the manufacturing method further includes: The outer surface of the blade, the inner wall of the outer ring frame, and the outer surface are respectively precision machined.

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