Hollow transmission shaft of a locomotive bogie coupling device, coupling device and method for manufacturing a hollow transmission shaft

Abstract

The present invention provides a transmission hollow shaft, a bogie coupler, and a manufacturing method for a transmission hollow shaft. The transmission hollow shaft comprises a shaft body, a flange structure, and an end surface tooth structure; the shaft body is of a hollow conical tubular structure and is provided with a large end and a small end; the flange structure is provided at the large end of the shaft body; the end surface tooth structure is provided at the small end of the shaft body; the shaft body, the flange structure, and the end surface tooth structure are made of particulate reinforced metal matrix composites; a metal matrix of the particulate reinforced metal matrix composites is 6-series aluminum alloy or 7-series aluminum alloy; a reinforcement material is a nanoscale inorganic nonmetal compound particle; and the content of the reinforcement materials is 5%-20%.

Description

Transmission hollow shaft, bogie coupling and method for preparing transmission hollow shaft

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority based on the Chinese application “Transmission hollow shaft, bogie coupling and method for preparing transmission hollow shaft” with application number 202111061098.8 filed on September 10, 2021, and all its contents are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the technical field of locomotive bogies, and in particular to a transmission hollow shaft, a bogie coupling, and a method for preparing the transmission hollow shaft. Background Art

[0004] The hollow shaft is an important force transmission component of the coupling and bears large torsional forces. Currently, the hollow shaft is usually made of steel metal. Traditional metal transmission hollow shafts have the following disadvantages:

[0005] Traditional metal hollow transmission shafts are heavy, with low specific modulus and specific stiffness. These shafts also have low resonant frequencies and critical speeds, significantly impacting the coupling's vibration resistance and increasing wheel-rail impact. They also generate significant noise during operation, increasing energy losses in the transmission system. Traditional metal hollow transmission shafts also have poor corrosion resistance and require protective paint treatment. During locomotive operation, there is a risk of splashing debris colliding with the shaft, causing paint to peel. Exposed metal parts are susceptible to corrosion and rust, leading to microcracks and other defects, thus reducing the shaft's fatigue life. Traditional metal hollow transmission shafts are highly crack-susceptible. Once microcracks develop during operation, they propagate rapidly, seriously impacting locomotive safety. Traditional production processes for hollow transmission shafts typically utilize open-die forging and mandrel drawing, resulting in low material utilization, low product qualification rates, labor-intensive and time-consuming processes, and extensive subsequent machining, resulting in high production costs.

[0006] Furthermore, existing metal materials cannot simultaneously meet the performance requirements of light weight, high specific strength, high specific stiffness, corrosion resistance, vibration resistance, fatigue resistance, and good wear resistance. The application of composite materials in transmission hollow shafts in this field has the following problems:

[0007] Currently, composite materials are primarily used in the rail transit industry for non-load-bearing structural components, such as vehicle interiors and interior decoration materials. Their application in load-bearing components lacks fundamental design theory and solutions, and lacks supporting specifications and standards. Composite materials often use fiber as reinforcement, but these materials are expensive. While the manufacturing process is simple, it requires extensive manual labor, resulting in inconsistent quality and high costs. Traditional secondary processing methods are unsuitable, hindering mass production. Composite materials are also often anisotropic, making them inadequate for use in bogie load-bearing components.

[0008] Summary of the Invention

[0009] A main purpose of the present disclosure is to overcome at least one of the defects of the above-mentioned prior art and provide a transmission hollow shaft that can withstand high rotation speeds and reduce vibration and effectively reduce wheel-rail impact.

[0010] To achieve the above objectives, the present disclosure adopts the following technical solutions:

[0011] According to one aspect of the present disclosure, a transmission hollow shaft is provided for a bogie coupling, wherein the transmission hollow shaft comprises an axle body, a flange structure and an end face tooth structure; the axle body is a hollow conical tubular structure and has a large end and a small end; the flange structure is arranged at the large end of the axle body, and the end face tooth structure is arranged at the small end of the axle body; the material of the axle body, the flange structure and the end face tooth structure is a particle-reinforced metal matrix composite material, the metal matrix of the particle-reinforced metal matrix composite material is a 6 series aluminum alloy or a 7 series aluminum alloy, and the reinforcement material is nano-scale inorganic non-metallic compound particles, and the content of the reinforcement material is 5% to 20%.

[0012] According to one embodiment of the present disclosure, the metal matrix of the particle-reinforced metal matrix composite material is 7075 aluminum alloy; and / or the particle diameter of the reinforcement material is 95nm to 105nm; and / or the reinforcement material is silicon carbide particles.

[0013] According to one embodiment of the present disclosure, the taper of the shaft body is 1°~1.5°; and / or, the wall thickness of the shaft body is 20mm~25mm; and / or, the thickness of the flange structure is 20mm~30mm; and / or, a plurality of first mounting holes are provided at the periphery of the flange structure; and / or, the thickness of the end face tooth structure is 30mm~40mm; and / or, the annular end face of the end face tooth structure is provided with multiple rows of end face teeth, and the extension directions of the multiple rows of end face teeth are not exactly the same; and / or, a plurality of second mounting holes are provided at the periphery of the end face tooth structure, and the second mounting holes are threaded holes and are embedded with threaded sleeves.

[0014] Another main purpose of the present disclosure is to overcome at least one of the above-mentioned defects of the prior art and provide a bogie coupling having the above-mentioned hollow transmission shaft.

[0015] To achieve the above objectives, the present disclosure adopts the following technical solutions:

[0016] According to another aspect of the present disclosure, a bogie coupling is provided, comprising a torque input force transmission plate, a torque output force transmission plate, and a transmission hollow shaft proposed in the present disclosure and described in the above-mentioned embodiment, wherein the transmission hollow shaft is connected to the torque input force transmission plate with the flange structure, and is connected to the torque output force transmission plate with the end face tooth structure.

[0017] As can be seen from the above technical solution, the transmission hollow shaft proposed in this disclosure utilizes a particle-reinforced metal matrix composite material with low density, high specific strength and modulus, and excellent wear resistance. Compared to traditional steel transmission hollow shafts, it can withstand higher speeds. The lightweight unsprung mass effectively reduces the impact between the wheel and rail, further alleviating vibration and noise. Because the particle-reinforced metal matrix composite material exhibits excellent mechanical and physical properties, such as crack insensitivity, high temperature resistance, wear resistance, a low thermal expansion coefficient, and good dimensional stability, it can improve the overall performance of the transmission hollow shaft.

[0018] Another main purpose of the present disclosure is to overcome at least one defect of the above-mentioned prior art and provide a method for preparing a transmission hollow shaft with simple process, low manufacturing cost, effective elimination of internal defects of the tube blank during the forming process, no cutting, and high raw material utilization rate.

[0019] To achieve the above objectives, the present disclosure adopts the following technical solutions:

[0020] According to another aspect of the present disclosure, a method for preparing a hollow transmission shaft is provided, comprising: preparing a tube blank by utilizing a particle-reinforced metal-based composite material, wherein the metal matrix of the particle-reinforced metal-based composite material is a 6-series aluminum alloy or a 7-series aluminum alloy, and the reinforcement material is nano-scale inorganic non-metallic compound particles, and the content of the reinforcement material is 5% to 20%; forming a flange structure by expanding and flanging one end of the tube blank; forming a shaft body of a tapered tubular structure by necking and spinning the remaining portion of the tube blank; and forming an end face tooth structure by multi-step upsetting processing on the other end of the tube blank.

[0021] According to one embodiment of the present disclosure, the step of preparing a tube blank using a particle-reinforced metal-based composite material includes: cleaning the inorganic non-metallic compound particles with a cleaning liquid to remove surface impurities; sintering the inorganic non-metallic compound particles at a high temperature to form an oxide film on their surface; adding the inorganic non-metallic compound particles to a semi-solid aluminum liquid and stirring it, and then pouring it into a mold to cool it to obtain the tube blank.

[0022] According to one embodiment of the present disclosure, the cleaning liquid is a hydrofluoric acid solution with a concentration of 2% to 5%; and / or, the cleaning time for cleaning the inorganic non-metallic compound particles is 10 min to 20 min; and / or, the sintering temperature of the high-temperature sintering of the inorganic non-metallic compound particles is 1200°C to 1400°C; and / or, the sintering time of the high-temperature sintering of the inorganic non-metallic compound particles is 4.5h to 5.5h; and / or, the stirring temperature of the inorganic non-metallic compound particles added to the semi-solid aluminum liquid is 570°C to 600°C; and / or, the stirring speed of the inorganic non-metallic compound particles added to the semi-solid aluminum liquid is 200r / min to 300r / min; and / or, the stirring time of the inorganic non-metallic compound particles added to the semi-solid aluminum liquid is 1.5h to 2.5h.

[0023] According to one embodiment of the present disclosure, the step of forming a flange structure by expanding and flanging one end of the tube blank includes: machining one end of the tube blank to form multiple petals; expanding one end of the tube blank to form an inverted cone surface; and pressing the inverted cone surface into a flat flange structure.

[0024] According to one embodiment of the present disclosure, the step of forming a shaft body with a tapered tubular structure by necking and spinning the remaining part of the tube blank includes: mounting the tube blank on a spinning machine core mold, and starting hot spinning after preheating; performing a temperature supplement after each hot spinning at least once, and preparing the shaft body on the tube blank after multiple hot spinning passes.

[0025] According to one embodiment of the present disclosure, in the step of forming the end face tooth structure by multi-step upsetting processing on the other end of the tube blank, the upsetting method is closed upsetting, and the upsetting processing technology includes a combination of flaring, upsetting and extrusion deformation. The upsetting process adopts local heating by induction coil, supports deformation by cold zone, constrains the upsetting of the outer diameter of the tube blank, and finally performs final forging.

[0026] As can be seen from the above technical solution, the method for manufacturing a hollow transmission shaft proposed in this disclosure utilizes a composite casting method followed by forging and forming, resulting in a simple process and low manufacturing costs. The forging process effectively improves the uniformity of particle distribution within the metal matrix and eliminates internal defects in the tube blank. This forming process also features minimal cutting and high raw material utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a schematic perspective structural diagram of a transmission hollow shaft according to an exemplary embodiment;

[0028] FIG2 is a schematic diagram of the three-dimensional structure of the transmission hollow shaft shown in FIG1 from another angle;

[0029] FIG3 is a schematic structural diagram of the flange structure of the transmission hollow shaft shown in FIG1 ;

[0030] FIG4 is a schematic structural diagram of the end face tooth structure of the transmission hollow shaft shown in FIG1 ;

[0031] FIG5 is a side view of FIG4;

[0032] FIG6 is a schematic plan view of the transmission hollow shaft shown in FIG1 ;

[0033] FIG7 is a schematic flow chart of a method for preparing a hollow transmission shaft according to an exemplary embodiment;

[0034] FIG8 is a process schematic diagram of several steps of the method for preparing the transmission hollow shaft shown in FIG7 or a schematic diagram of the three-dimensional structure of the transmission hollow shaft;

[0035] FIG9 is a schematic diagram of the three-dimensional structure of the tube blank shown in FIG8 . Specific embodiments

[0036] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be embodied in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent like or similar structures, and thus their detailed description will be omitted.

[0037] Referring to Figure 1, a representative perspective view of the hollow transmission shaft proposed in the present disclosure is shown. In this exemplary embodiment, the hollow transmission shaft proposed in the present disclosure is described using a bogie coupling for a locomotive as an example. Those skilled in the art will readily appreciate that various modifications, additions, substitutions, deletions, or other variations may be made to the following specific embodiments to apply the relevant designs of the present disclosure to other types of couplings or other structures. These variations remain within the scope of the principles of the hollow transmission shaft proposed in the present disclosure.

[0038] As shown in Figure 1, in this embodiment, the transmission hollow shaft proposed in the present disclosure includes an axle body 110, a flange structure 120, and an end face tooth structure 130. Referring to Figures 2 to 6, Figure 2 represents a schematic diagram of the three-dimensional structure of the transmission hollow shaft from another angle; Figure 3 represents a schematic diagram of the structure of the flange structure 120 of the transmission hollow shaft; Figure 4 represents a schematic diagram of the structure of the end face tooth structure 130 of the transmission hollow shaft; Figure 5 represents a side view of Figure 4; and Figure 6 represents a schematic plan view of the transmission hollow shaft. The following, in conjunction with the above-mentioned figures, will describe in detail the structure, connection method, and functional relationship of the main components of the transmission hollow shaft proposed in the present disclosure.

[0039] As shown in Figures 1 to 6, in this embodiment, the shaft body 110 is a hollow conical tubular structure, which can ensure the radial clearance compensation between the transmission hollow shaft and the locomotive axle. The shaft body 110 has a large end 111 and a small end 112. The flange structure 120 is provided at the large end 111 of the shaft body 110, and the stress distribution and weight reduction of the components can be fully considered in the structural design. The end face tooth structure 130 is provided at the small end 112 of the shaft body 110. The material of the shaft body 110, the flange structure 120 and the end face tooth structure 130 is a particle reinforced metal matrix composite material, the metal matrix of the particle reinforced metal matrix composite material is 6 series aluminum alloy or 7 series aluminum alloy, and the reinforcement material is nano-scale inorganic non-metallic compound particles, and the content of the reinforcement material is 5% to 20%.

[0040] Through the above-mentioned design, the transmission hollow shaft proposed in the present disclosure adopts a particle-reinforced metal-based composite material with low density, high specific strength, high specific modulus, and good wear resistance. Compared with the traditional steel transmission hollow shaft, it can withstand higher rotation speeds, and the lightweight unsprung mass can effectively reduce the impact between the wheel and rail, further reducing vibration and noise. Since the particle-reinforced metal-based composite material has excellent mechanical and physical properties such as crack insensitivity, high temperature resistance, wear resistance, small thermal expansion coefficient, and good dimensional stability, it can improve the overall performance of the transmission hollow shaft. In addition, taking into account the unfavorable factors such as the high cost of composite materials, various anisotropic properties, poor operability of the forming process, and unsuitability for mass production, the present disclosure starts from the two aspects of raw material cost control and simplification of the forming process, and deeply carries out the design of the particle-reinforced metal-based composite transmission hollow shaft.

[0041] Optionally, in this embodiment, the metal matrix of the particle-reinforced metal matrix composite material can be 7075 aluminum alloy. 7 series aluminum alloys have higher strength and are closer to steel in terms of hardness. Specifically, the chemical composition of 7075 aluminum alloy is shown in the following table:

[0042] MgSiFeCuMnCrZnTiAl2.50.170.271.40.070.235.50.04Other

[0043] Table 1: Chemical composition of 7075 aluminum alloy (wt%)

[0044] In addition, in some embodiments, the metal matrix of the particle-reinforced metal matrix composite material can also be 6061 aluminum alloy. Specifically, the chemical composition of 6061 aluminum alloy is shown in the following table:

[0045] MgSiFeCuMnZnAl0.9750.590.0920.2890.080.031Other

[0046] Table 2: Chemical composition of 6061 aluminum alloy (wt%)

[0047] Optionally, in this embodiment, the reinforcement material may be silicon carbide (SiC) particles. Specifically, the performance parameters of the silicon carbide particles are shown in the following table:

[0048]

[0049] Table 3: Silicon carbide particle performance parameters

[0050] It should be noted that in this embodiment, 7075 aluminum alloy is selected as the metal matrix, and silicon carbide particles are added to the metal matrix as a reinforcement material. This material combination significantly reduces the cost of long fibers in related designs. Furthermore, the silicon carbide particle content is relatively low, for example, 5% to 20%, which significantly reduces the raw material cost of the composite material. Furthermore, the excellent compatibility of silicon carbide particles with the aluminum alloy results in isotropic composite material properties.

[0051] Optionally, in this embodiment, the particle diameter of the reinforcement material can be 95 nm to 105 nm, such as 95 nm, 98 nm, 102 nm, 105 nm, etc., and preferably 100 nm. In some embodiments, the particle diameter of the reinforcement material can also be less than 95 nm, or greater than 105 nm, such as 94 nm, 106 nm, etc., but is not limited thereto.

[0052] Optionally, in this embodiment, the taper of the shaft body 110 can be 1° to 1.5°, such as 1°, 1.1°, 1.3°, 1.5°, etc. In some embodiments, the taper of the shaft body 110 can also be less than 1°, or greater than 1.5°, such as 0.9°, 1.6°, etc., but is not limited thereto.

[0053] Optionally, in this embodiment, the wall thickness of the shaft body 110 can be 20 mm to 25 mm, such as 20 mm, 21 mm, 23 mm, 25 mm, etc. In some embodiments, the wall thickness of the shaft body 110 can also be less than 20 mm, or greater than 25 mm, such as 19 mm, 26 mm, etc., but is not limited thereto.

[0054] Optionally, in this embodiment, taking a typical bogie coupling as an example, the length of the axle body 110 can be 1200 mm. In some embodiments, the length of the axle body 110 can be flexibly adjusted based on the different types of bogie couplings to be used, but is not limited thereto.

[0055] Optionally, in this embodiment, the thickness of the flange structure 120 can be 20 mm to 30 mm, such as 20 mm, 23 mm, 26 mm, 30 mm, etc., and preferably 25 mm. In some embodiments, the thickness of the flange structure 120 can also be less than 20 mm, or greater than 30 mm, such as 19 mm, 31 mm, etc., but is not limited thereto.

[0056] Optionally, as shown in Figures 1 to 3, in this embodiment, a plurality of first mounting holes 121 may be provided on the periphery of the flange structure 120. Accordingly, the flange structure 120 can be connected to the bogie coupling torque input force transmission plate via connectors, such as screws, provided in the first mounting holes 121.

[0057] Furthermore, based on the design of the first mounting hole 121 provided in the flange structure 120, in this embodiment, taking a typical bogie coupling as an example, the diameter of the first mounting hole 121 can be 47 mm. In some embodiments, the diameter of the first mounting hole 121 can be flexibly adjusted based on the desired type of bogie coupling, but is not limited thereto.

[0058] Furthermore, as shown in Figures 1 to 3 , based on the design of the first mounting holes 121 provided on the flange structure 120, in this embodiment, the flange structure 120 may be provided with eight first mounting holes 121. In some embodiments, the number of first mounting holes 121 may be flexibly adjusted based on different types of bogie couplings to be used or based on different flange structures 120, without being limited thereto.

[0059] Optionally, in this embodiment, the thickness of the end face tooth structure 130 can be 30 mm to 40 mm, such as 30 mm, 34 mm, 37 mm, 40 mm, etc., and preferably 36 mm. In some embodiments, the thickness of the end face tooth structure 130 can also be less than 30 mm, or greater than 40 mm, such as 29 mm, 41 mm, etc., but is not limited thereto.

[0060] Alternatively, as shown in Figures 2 and 4 , in this embodiment, the annular end surface of the face tooth structure 130 may be provided with multiple rows of face teeth 131, and the extension directions of the multiple rows of face teeth 131 may not be identical. For example, the annular end surface of the face tooth structure 130 may be provided with four rows of face teeth 131, and the four rows of face teeth 131 may be arranged in a roughly cross shape.

[0061] Optionally, as shown in Figures 1 and 4, in this embodiment, the periphery of the face tooth structure 130 may be provided with a plurality of second mounting holes 132. On this basis, the second mounting holes 132 may be threaded holes and embedded with threaded sleeves, such as, but not limited to, wire threaded sleeves. Accordingly, the face tooth structure 130 can be connected to the torque output transmission disc of the bogie coupling via a connector, such as a screw, provided in the second mounting holes 132. The provision of the threaded sleeves can improve the connection strength, making it loose and capable of repeated assembly and disassembly. As an important transmission structure in the bogie coupling, the face tooth structure 130 can ensure the reliability of its transmission.

[0062] Furthermore, based on the design of the second mounting hole 132 provided on the face gear structure 130, in this embodiment, taking a typical bogie coupling as an example, the diameter of the second mounting hole 132 can be 16 mm. In some embodiments, the diameter of the second mounting hole 132 can be flexibly adjusted according to the different types of bogie couplings to be used, but is not limited thereto.

[0063] Furthermore, as shown in FIG4 , based on the design of the face gear structure 130 being provided with second mounting holes 132, in this embodiment, the face gear structure 130 may be provided with eight second mounting holes 132. In some embodiments, the number of second mounting holes 132 may be flexibly adjusted based on different types of truck couplings to be used or based on different face gear structures 130, without being limited thereto.

[0064] Based on the above detailed description of the exemplary embodiment of the transmission hollow shaft proposed in the present disclosure, an exemplary embodiment of the bogie coupling proposed in the present disclosure will be described below.

[0065] In this embodiment, the bogie coupling proposed in this disclosure includes a torque input force transmission plate, a torque output force transmission plate, and a hollow transmission shaft proposed in this disclosure and described in detail in the above embodiments. The hollow transmission shaft is connected to the torque input force transmission plate via a flange structure 120 and to the torque output force transmission plate via a face gear structure 130.

[0066] Based on the above detailed description of the exemplary embodiment of the transmission hollow shaft proposed in the present disclosure, an exemplary embodiment of the method for preparing the transmission hollow shaft proposed in the present disclosure will be described below.

[0067] Referring to Figure 7 , a representative flow chart of the method for manufacturing a hollow transmission shaft according to the present disclosure is shown. In conjunction with Figures 8 and 9 , Figure 8 represents a schematic diagram of the process steps involved in the method for manufacturing a hollow transmission shaft, or a schematic diagram of the three-dimensional structure of the hollow transmission shaft; Figure 9 represents a schematic diagram of the three-dimensional structure of a tube blank 230. The method for manufacturing a hollow transmission shaft according to the present disclosure will be described in detail below, in conjunction with the aforementioned figures.

[0068] As shown in FIG7 and FIG8 , in this embodiment, the method for preparing the hollow transmission shaft proposed in the present disclosure includes:

[0069] Step S1: preparing a tube blank 230 using a particle-reinforced metal matrix composite material, wherein the metal matrix of the particle-reinforced metal matrix composite material is a 6-series aluminum alloy or a 7-series aluminum alloy, and the reinforcement material is nano-scale inorganic non-metallic compound particles 210, with the reinforcement material content being 5% to 20%;

[0070] Step S2: forming a flange structure 120 by flaring and flanging one end of the tube blank 230;

[0071] Step S3: The remaining portion of the tube blank 230 is subjected to necking and spinning to form the shaft body 110 of a tapered tubular structure;

[0072] Step S4: The other end of the tube blank 230 is subjected to a multi-step upsetting process to form an end face gear structure 130 .

[0073] Through the above-described design, the method for preparing a hollow transmission shaft proposed in this disclosure utilizes a composite casting method and a forging secondary forming process, resulting in a simple process and low manufacturing cost. The forging process effectively improves the uniformity of particle distribution within the metal matrix and eliminates internal defects within the tube blank 230. This forming process features minimal cutting and high raw material utilization. The machining process effectively improves the uniformity of particle distribution within the matrix, eliminates defects such as porosity and shrinkage within the tube blank 230, and increases the elastic modulus and shear stiffness of the hollow transmission shaft, significantly enhancing its mechanical properties and meeting the operational requirements of the hollow transmission shaft.

[0074] Optionally, in this embodiment, step S1 may specifically include:

[0075] Cleaning the inorganic non-metallic compound particles 210 with a cleaning solution to remove surface impurities;

[0076] Sintering the inorganic non-metallic compound particles 210 at a high temperature to form an oxide film 211 on the surface thereof;

[0077] The inorganic non-metallic compound particles 210 are added to the semi-solid aluminum liquid 220 and stirred, and then poured into a mold and cooled to obtain a tube blank 230.

[0078] Specifically, in this embodiment, taking silicon carbide as the reinforcement material, after the silicon carbide particles are sintered at a high temperature, the oxide film 211 formed on the surface thereof is made of silicon oxide (SiO 2 ).

[0079] Furthermore, based on the specific design of step S1 above, in this embodiment, the cleaning liquid can be a hydrofluoric acid solution with a concentration of 2% to 5%. The concentration of the hydrofluoric acid solution can be, for example, 2%, 4%, 5%, etc., and can preferably be 3%. In some embodiments, the concentration of the hydrofluoric acid solution can also be less than 2%, or greater than 5%, for example, 1.8%, 5.1%, etc. In addition, other types of solutions can also be used as cleaning liquids, and the present invention is not limited to this.

[0080] Furthermore, based on the specific design of step S1 above, in this embodiment, the cleaning time for cleaning the inorganic non-metallic compound particles 210 can be 10 minutes to 20 minutes, for example, 10 minutes, 12 minutes, 18 minutes, 20 minutes, etc., and can preferably be 15 minutes. In some embodiments, the cleaning time for cleaning the inorganic non-metallic compound particles 210 can also be less than 10 minutes, or can be greater than 20 minutes, for example, 9 minutes, 22 minutes, etc., but is not limited thereto.

[0081] Furthermore, based on the specific design of step S1 above, in this embodiment, the sintering temperature of the high-temperature sintering of the inorganic non-metallic compound particles 210 can be 1200° C. to 1400° C., for example, 1200° C., 1250° C., 1350° C., 1400° C., etc., and can preferably be 1300° C. In some embodiments, the sintering temperature of the high-temperature sintering of the inorganic non-metallic compound particles 210 can also be lower than 1200° C., or higher than 1400° C., for example, 1190° C., 1420° C., etc., but the present invention is not limited thereto.

[0082] Furthermore, based on the specific design of step S1 above, in this embodiment, the sintering time of the high-temperature sintering of the inorganic non-metallic compound particles 210 can be 4.5 hours to 5.5 hours, for example, 4.5 hours, 5.5 hours, etc., and can preferably be 5 hours. In some embodiments, the sintering time of the high-temperature sintering of the inorganic non-metallic compound particles 210 can also be less than 4.5 hours, or can be greater than 5.5 hours, for example, 4.4 hours, 5.6 hours, etc., but is not limited thereto.

[0083] Furthermore, based on the specific design of step S1 above, in this embodiment, the stirring temperature when the inorganic non-metallic compound particles 210 are added to the semi-solid aluminum liquid 220 can be 570°C to 600°C, for example, 570°C, 580°C, 590°C, 600°C, etc. In some embodiments, the stirring temperature when the inorganic non-metallic compound particles 210 are added to the semi-solid aluminum liquid 220 can also be lower than 570°C, or higher than 600°C, for example, 565°C, 605°C, etc., but the present invention is not limited thereto.

[0084] Furthermore, based on the specific design of step S1 above, in this embodiment, the stirring speed of the inorganic non-metallic compound particles 210 when added to the semi-solid aluminum liquid 220 can be 200 r / min to 300 r / min, for example, 200 r / min, 240 r / min, 270 r / min, 300 r / min, etc., and can preferably be 250 r / min. In some embodiments, the stirring speed of the inorganic non-metallic compound particles 210 when added to the semi-solid aluminum liquid 220 can also be less than 200 r / min, or greater than 300 r / min, for example, 195 r / min, 302 r / min, etc., but is not limited thereto.

[0085] Furthermore, based on the specific design of step S1 above, in this embodiment, the stirring time after the inorganic non-metallic compound particles 210 are added to the semi-solid aluminum liquid 220 can be 1.5 hours to 2.5 hours, for example, 1.5 hours, 1.8 hours, 2.5 hours, etc., and can preferably be 2 hours. In some embodiments, the stirring time after the inorganic non-metallic compound particles 210 are added to the semi-solid aluminum liquid 220 can also be less than 1.5 hours, or can be greater than 2.5 hours, for example, 1.4 hours, 2.6 hours, etc., without limitation thereto.

[0086] Optionally, in this embodiment, step S2 may specifically include:

[0087] One end of the tube blank 230 is machined to form a multi-petal 231;

[0088] Expand one end of the tube blank 230 to form an inverted cone;

[0089] The inverted conical surface is pressed into a flat flange structure 120 .

[0090] Furthermore, based on the specific design of step S2 above, in this embodiment, one end of the tube blank 230 can be machined to form three petals 231. In some embodiments, one end of the tube blank 230 can also be machined to form two petals 231, four petals 231, or more than four petals 231, without limitation.

[0091] Furthermore, based on the specific design of the above step S2, in this embodiment, the islands formed by flaring at one end of the tube blank 230 may be approximately 90°.

[0092] Optionally, in this embodiment, step S3 may specifically include:

[0093] The tube blank 230 is mounted on the core die of the spinning machine and hot spinning is started after preheating;

[0094] The hot spinning is performed at least once, and the temperature is replenished once. After multiple hot spinning passes, the shaft body 110 is prepared from the tube blank 230 .

[0095] Furthermore, based on the specific design of step S3 above, in this embodiment, the preheating temperature of the tube blank 230 after being installed in the core mold of the spinning machine can be 350° C. to 450° C., for example, 350° C., 380° C., 410° C., 450° C., etc., and can preferably be 400° C. In some embodiments, the preheating temperature of the tube blank 230 after being installed in the core mold of the spinning machine can also be lower than 350° C., or higher than 450° C., for example, 345° C., 455° C., etc., but the present invention is not limited thereto.

[0096] Furthermore, based on the specific design of the above step S3, in this embodiment, the nominal reduction of the hot spinning pass of the spinning machine on the tube blank 230 can be 1.5.

[0097] Furthermore, based on the specific design of the above step S3, in this embodiment, a temperature supplementation process may be performed after every two passes of hot spinning.

[0098] Optionally, in this embodiment, the upsetting method for step S4 may be closed-type upsetting, and the upsetting process may include a combination of flaring, upsetting, and extrusion deformation. The upsetting process utilizes localized heating by an induction coil, supporting deformation in a cold zone, and constraining the outer diameter of the tube 230 to be upset, followed by final forging.

[0099] Furthermore, based on the specific design of step S4 above, in this embodiment, the ratio of the thickness of the upset flange formed at the small end of the shaft body 110 by the upsetting method to the wall thickness of the tube blank 230 can be 1.5 to 2, for example, 1.5, 1.6, 1.8, 2, etc. In some embodiments, the ratio of the thickness of the upset flange to the wall thickness of the tube blank 230 can also be less than 1.5, or greater than 2, for example, 1.45, 2.1, etc., without limitation thereto.

[0100] Furthermore, based on the specific design of step S4 above, in this embodiment, the heating temperature of the local heating using the induction coil during the upsetting process is 350°C to 450°C, for example, 350°C, 400°C, 420°C, 450°C, etc. In some embodiments, the heating temperature of the local heating using the induction coil during the upsetting process may be lower than 350°C, or higher than 450°C, for example, 345°C, 455°C, etc., but the present invention is not limited thereto.

[0101] In summary, in response to the current market demand for hollow transmission shafts, the present disclosure provides a hollow transmission shaft suitable for bogie couplings. This hollow transmission shaft utilizes a particle-reinforced metal-matrix composite material. Leveraging the inherent properties of this material, the present disclosure addresses the technical challenges of existing components, which struggle to simultaneously address the requirements for vibration resistance, fatigue resistance, corrosion resistance, high strength, light weight, and wear resistance. Consequently, the present disclosure not only effectively addresses issues such as vibration, impact, and noise, but also reduces the overall component weight to less than 50% of its original weight, alleviating wheel-rail impact by reducing unsprung mass.

[0102] Specifically, the transmission hollow shaft proposed in the present disclosure has at least the following advantages:

[0103] The transmission hollow shaft proposed in the present disclosure is light in weight, and has a specific modulus and specific stiffness that are significantly higher than those of steel. It can significantly increase the maximum speed and the unbalanced critical speed by 15% to 25%, while generating less vibration noise and reducing the energy loss of the transmission system.

[0104] The hollow transmission shaft proposed in this disclosure exhibits strong corrosion resistance. The metal-based composite material exhibits a passivation potential (Ecr) close to that of stainless steel and significantly lower than that of ordinary steel. Its passivation current density (Icr) lies between that of white cast iron and stainless steel, closer to that of stainless steel, and exhibits a wide passivation region. The metal-based composite material exhibits strong passivation capabilities, a stable passivation film, and excellent electrochemical corrosion resistance, comparable to that of stainless steel.

[0105] The transmission hollow shaft proposed in the present disclosure has low crack sensitivity. Since the reinforcing particles have many advantages over the matrix material, such as high hardness, high strength, high modulus, and low thermal expansion coefficient, cracks need to bypass the reinforcing particles when extending inside the composite material, which hinders the expansion of the cracks.

[0106] The hollow transmission shaft proposed in this disclosure features a flange structure 120 at one end and an end face gear structure 130 at the other. The end face gear structure 131 has a threaded hole with a wire screw inserted into it. The use of end face gear structure 130 leverages the wear resistance of particle-reinforced metal matrix composites while improving the precision of the transmission system. The wire screw inserted into the threaded hole enhances the connection strength, prevents loosening, and allows for repeated disassembly and reuse, thus improving the connection strength.

[0107] While the present disclosure has been described with reference to several exemplary embodiments, it should be understood that the terms used are illustrative and exemplary rather than restrictive. Since the present disclosure can be embodied in many forms without departing from the spirit or substance of the disclosure, it should be understood that the above-described embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope of the appended claims. Therefore, all changes and modifications that fall within the scope of the claims or their equivalents are intended to be covered by the appended claims.

Claims

1. A transmission hollow shaft, used for a bogie coupling, the transmission hollow shaft comprises an axle body, a flange structure and an end face tooth structure; the axle body is a hollow conical tubular structure, and has a large end and a small end; the flange structure is arranged at the large end of the axle body, and the end face tooth structure is arranged at the small end of the axle body; the material of the axle body, the flange structure and the end face tooth structure is a particle reinforced metal matrix composite material, the metal matrix of the particle reinforced metal matrix composite material is a 6 series aluminum alloy or a 7 series aluminum alloy, and the reinforcement material is nano-scale inorganic non-metallic compound particles, and the content of the reinforcement material is 5% to 20%.

2. The transmission hollow shaft according to claim 1, in, The metal matrix of the particle-reinforced metal matrix composite material is 7075 aluminum alloy.

3. The transmission hollow shaft according to claim 1, in, The particle diameter of the reinforcement material is 95nm-105nm.

4. The transmission hollow shaft according to claim 1, in, The reinforcement material is silicon carbide particles.

5. The transmission hollow shaft according to claim 1, in, The taper of the shaft body is 1° to 1.5°.

6. The transmission hollow shaft according to claim 1, in, The wall thickness of the shaft body is 20 mm to 25 mm.

7. The transmission hollow shaft according to claim 1, in, The thickness of the flange structure is 20 mm to 30 mm.

8. The transmission hollow shaft according to claim 1, in, A plurality of first mounting holes are arranged on the periphery of the flange structure.

9. The transmission hollow shaft according to claim 1, in, The thickness of the end face tooth structure is 30 mm to 40 mm.

10. The transmission hollow shaft according to claim 1, in, The annular end face of the face gear structure is provided with multiple rows of face gears, and the extension directions of the multiple rows of face gears are not completely the same.

11. The transmission hollow shaft according to claim 1, in, A plurality of second mounting holes are arranged on the periphery of the end face gear structure, and the second mounting holes are threaded holes and are embedded with threaded sleeves.

12. A bogie coupling, comprising: a torque input force transfer plate and a torque output force transfer plate; and The transmission hollow shaft according to any one of claims 1 to 11 is connected to the torque input force transmission disc by the flange structure, and is connected to the torque output force transmission disc by the end face gear structure.

13. A method for preparing a transmission hollow shaft, comprising: A tube blank is prepared by using a particle-reinforced metal matrix composite material, wherein the metal matrix of the particle-reinforced metal matrix composite material is a 6-series aluminum alloy or a 7-series aluminum alloy, and the reinforcement material is nano-scale inorganic non-metallic compound particles, and the content of the reinforcement material is 5% to 20%; Forming a flange structure by expanding and flanging one end of the tube blank; The remaining part of the tube blank is subjected to necking and spinning to form an axle body of a tapered tubular structure; The other end of the tube blank is subjected to multi-step upsetting processing to form an end face tooth structure.

14. The method for preparing the transmission hollow shaft according to claim 13, in, The step of preparing a tube blank by using a particle-reinforced metal matrix composite material comprises: Cleaning the inorganic non-metallic compound particles with a cleaning solution to remove surface impurities; Sintering the inorganic non-metallic compound particles at a high temperature to form an oxide film on the surface of the particles; The inorganic non-metallic compound particles are added into semi-solid aluminum liquid and stirred, and then poured into a mold and cooled to obtain the tube blank.

15. The method for preparing the transmission hollow shaft according to claim 14, in, The cleaning solution is a hydrofluoric acid solution with a concentration of 2% to 5%.

16. The method for preparing the transmission hollow shaft according to claim 14, in, The cleaning time of the inorganic non-metallic compound particles is 10 minutes to 20 minutes.

17. The method for preparing the transmission hollow shaft according to claim 14, in, The sintering temperature of the inorganic non-metallic compound particles is 1200°C to 1400°C.

18. The method for preparing the transmission hollow shaft according to claim 14, in, The high-temperature sintering time of the inorganic non-metallic compound particles is 4.5 hours to 5.5 hours.

19. The method for preparing a transmission hollow shaft according to claim 14, in, The stirring temperature when the inorganic non-metallic compound particles are added into the semi-solid aluminum liquid is 570°C to 600°C.

20. The method for preparing a transmission hollow shaft according to claim 14, in, The inorganic non-metallic compound particles are added into the semi-solid aluminum liquid at a stirring speed of 200 r / min to 300 r / min.

21. The method for preparing a transmission hollow shaft according to claim 14, in, The inorganic non-metallic compound particles are added to the semi-solid aluminum liquid and stirred for 1.5 hours to 2.5 hours.

22. The method for preparing the transmission hollow shaft according to claim 13, in, The step of forming a flange structure by expanding and flanging one end of the tube blank comprises: Machining one end of the tube blank to form multiple petals; Expanding one end of the tube blank to form an inverted cone; The flange structure is formed by pressing the inverted cone surface into a flat surface.

23. The method for preparing the transmission hollow shaft according to claim 13, in, The step of forming the axle body of the tapered tubular structure by necking and spinning the remaining part of the tube blank comprises: The tube blank is mounted on a core die of a spinning machine, and hot spinning is started after preheating; Each time the hot spinning is performed at least once, the temperature is replenished once. After multiple hot spinning passes, the shaft body is prepared from the tube blank.

24. The method for preparing a transmission hollow shaft according to claim 13, in, In the step of forming the end face tooth structure by multi-step upsetting processing on the other end of the tube blank, the upsetting method is closed upsetting, and the upsetting process includes a combination of flaring, upsetting and extrusion deformation. The upsetting process adopts induction coil local heating, supports deformation by cold zone, constrains the outer diameter upsetting of the tube blank, and finally final forging.

Images