Special reducing shaft for bearing large mechanical wheel

Abstract

The invention discloses a variable-diameter shaft special for bearing a large mechanical wheel. High-strength steel is forged into a variable-diameter shaft blank; the variable-diameter shaft blank is subjected to lathe machining and variable diameter to form a variable-diameter shaft comprising a middle shaft section, a hub shaft fixed connection section, a hub shaft fixed connection section and bearing box isolation section, a bearing box section and an energy transmission shaft section; the middle shaft section of the variable-diameter shaft bears large torque and bending moment, and the torque and the bending moment are gradually reduced from the middle shaft section to the two ends. The hub fixedly-connecting section is fixedly connected with a polygonal hub, and the polygonal hub forms a mechanical wheel supporting frame fulcrum; bearing box sections at two ends of the reducing shaft are respectively provided with two groups of bearings; and the energy transmission shaft section is connected with a gearbox mechanical device.

Description

Technical Field

[0001] This invention relates to the field of large mechanical transmission components, specifically to a special variable diameter shaft for supporting large mechanical wheels, suitable for 6 MW-50 MW high-power mechanical wheel power generation systems, undertaking the functions of supporting, rotating and transmitting energy of large mechanical wheels. Background Technology

[0002] The country advocates a dual-carbon economy, aiming to reach peak carbon emissions by 2030 and achieve carbon neutrality by 2060. From a macro perspective, with the development of a dual-carbon economy, coal-fired power generation will gradually decrease, while clean energy power generation will increase exponentially. However, traditional power generation models are affected by policies, resources, and the environment. Current power generation models mainly include nuclear power, hydropower, thermal power, wind power, solar power, and small-scale mechanical power generation, utilizing these energy sources as power sources for generators. However, each of these methods has its drawbacks. For example, nuclear power and hydropower are subject to policy, technology, conditions, and environmental controls, hindering their expansion. Thermal power generation consumes large amounts of materials and pollutes the environment. Wind power generation is subject to changes in wind strength due to natural climate changes, resulting in poor power generation stability. Solar power generation has short effective sunshine hours and cannot generate electricity around the clock. The voltage and frequency of wind and solar power generation do not meet grid connection standards, requiring huge investments in energy storage and inverter conversion devices. Despite decades of effort, small-scale mechanical power generation has only maintained a power generation capacity between 0.05 MW and 0.8 MW due to imperfect mechanical equipment and scientific and technological means. Therefore, it is urgent to develop a special variable-diameter shaft to support large mechanical wheels and withstand the enormous bending forces generated by the mass and rotation of the wheels, so as to provide a power source for the generator to support the rotation of large mechanical wheels.

[0003] To overcome the technical bottlenecks in mechanical energy power generation, the inventors have applied for invention patents for "A Complete Set of Mechanical Wheel Power Generation Device" (application number: 2025102407114) and "A Method for Power Generation Using a Mechanical Wheel System Device" (application number: 2025102371396), establishing a core technology system for large-scale mechanical wheel power generation. However, in large-scale mechanical wheel power generation systems, the mechanical wheels typically have a diameter greater than 20m, weigh over 100 tons, and rotate at speeds of 20r / min-60r / min. The core component for load-bearing and transmission—the variable-diameter shaft—faces severe challenges: existing general-purpose variable-diameter shafts are mostly suitable for small and medium-sized equipment (load ≤ 50 tons, speed ≥ 100r / min). When applied to large mechanical wheels, they suffer from insufficient bending strength, easy loosening of hub connections, poor bearing compatibility, and low energy transfer efficiency, failing to meet the requirements for long-term stable operation under high loads and low speeds. Therefore, developing a dedicated variable-diameter shaft to solve the load-bearing and transmission problems of large mechanical wheels is crucial for supporting the implementation of high-power mechanical wheel power generation systems. Summary of the Invention

[0004] The purpose of this invention is to provide a special variable diameter shaft for supporting large mechanical wheels. By optimizing the structural design, material selection and connection method, it meets the load-bearing requirements of large mechanical wheels (weight ≥ 100 tons, speed 20r / min-60r / min), ensures the structural safety and long-term stability of the shaft under large bending force and centrifugal force, and provides a reliable power transmission channel for 6 MW-50 MW generator sets.

[0005] The technical solution of this invention is derived from simulation experiments of the energy and dynamic performance of a mechanical wheel: Based on the mechanical energy formula E = kinetic energy (1 / 2mv²) + gravitational potential energy (mgh), the moment of inertia formula J = mr², and the centrifugal force formula F = mω²r, through wind tunnel tests and multi-scenario simulations, the matching relationships of factors such as mass m, height h, speed v, mechanical wheel radius r, and angular velocity ω are optimized to determine the core basic parameters: mechanical wheel weight 100 tons, diameter 20m, counterweight block 17.5 tons / block, rotational speed 20r / min-60r / min, and angular velocity ω = 2 / 3π-2π rad / s. Based on the above parameters, through material mechanics calculations (σ = M / Wz, where σ is stress, M is bending moment, and Wz is section modulus), combined with a safety factor n = 2.5, the dimensions, materials, and structural design of the variable diameter shaft are determined to ensure that the shaft can withstand a maximum bending moment of 1.63 × 10⁻⁶. 5 When the stress is kN·m, the allowable value [σs] is less than or equal to the allowable value [σs] (σs is the yield strength of high-strength steel).

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a special variable diameter shaft for bearing large mechanical wheels, characterized in that it uses a yield strength ≥690MPa. High-strength steel is forged into a variable-diameter shaft blank. After passing flaw detection, the variable-diameter shaft blank is machined into a series of interconnected intermediate shaft sections, hub-fixed sections, isolation sections, bearing housing sections, and energy transmission shaft sections. The intermediate shaft section, which bears the greatest bending force, has the thickest diameter, gradually decreasing in diameter towards both ends, with the smallest diameter at both ends and the energy transmission shaft section. The hub-fixed section uses keyways and flat keys to fix polygonal hubs, which form the fulcrum of the mechanical wheel support frame. Two sets of bearings are installed in the bearing housings at both ends of the variable-diameter shaft. The energy transmission shaft section is divided into an energy input transmission shaft section for maintaining the uniform rotation of the mechanical wheel and an energy output transmission shaft section for the mechanical wheel. A large gear disk or a shrink sleeve is installed in the rotational energy input transmission shaft section. The large gear disk is driven by gear meshing of an energy input reduction gearbox. The mechanical wheel energy output transmission shaft section is connected to a speed-increasing gearbox through a shrink sleeve or a large spline.

[0007] Furthermore, according to claim 1, the variable diameter shaft for bearing large mechanical wheels is characterized in that the total length of the variable diameter shaft is 6000mm to 8000mm, the diameter of the intermediate shaft section is 600mm to 800mm, and the diameter of the energy transmission shaft section is 500mm to 600mm.

[0008] Furthermore, the variable diameter shaft can withstand a load of over 100 tons and has a rotation speed of 20 r / min to 60 r / min.

[0009] Furthermore, the middle section of the hubs on both sides of the variable diameter shaft is the center of a large mechanical wheel, with a length and width greater than 2500mm.

[0010] Furthermore, the inner diameter of the hub is located at the hub shaft connection section; the outer edge is formed by eighteen equilateral polygons; each equilateral polygon constitutes a support node for the large mechanical wheel; the polygonal hubs are symmetrically distributed on both sides of the intermediate shaft section; the variable diameter shaft hub connection section is secured by a combination of keyways and flat keys or by planing the shaft section into a polygonal hub; the hub rotates together with the variable diameter shaft.

[0011] Furthermore, the bearing housing is formed by casting or welding; two sets of bearings are installed at the bearing housings at both ends of the variable diameter shaft, and the inner and outer diameters of the two sets of bearings are different, with the bearings on the inner side of the bearing housing being larger than those on the outer side.

[0012] Furthermore, the variable diameter shaft input energy transmission section is fitted with a shrink sleeve connected to a reduction planetary gearbox; the reduction planetary gearbox reduces the input high-speed power (3000r / min~5000r / min) to 20r / min~60r / min before transmitting it to the variable diameter shaft.

[0013] Furthermore, the bearing housing is provided with a lubricating oil circulation channel for bearing lubrication and bearing cooling; the lubricating oil circulation channel is connected to a lubricating oil pump station device.

[0014] The technical solution of this invention is based on the simulation test results of the basic values ​​of various factors affecting the variable diameter shaft of a mechanical wheel. Specific data is used to illustrate the realization of a special variable diameter shaft for bearing large mechanical wheels. This is specifically designed for large mechanical wheels with a diameter greater than 20m; counterweights greater than 17.5 tons; a wheel weight greater than 100 tons; and a wheel rotation speed of 20r / min to 60r / min, generating enormous rotational inertia and kinetic energy. Regarding structural strength and safety, the centrifugal force field distribution at the wheel's rotational speed is determined. The overall ability of the wheel rim, support, hub, bearing housing, and counterweight to resist bending forces on the special variable diameter shaft, as well as the material's yield strength, stiffness, and fatigue life, are assessed to ensure the safety, stability, and mechanical fatigue resistance under the bending forces of a mechanical wheel with a mass exceeding 100 tons at high speeds. By changing the data of the factors affecting the force on the variable diameter shaft, the reliable structure of the special variable diameter shaft is determined. This addresses the power energy problem of generators, optimizes the kinetic energy of existing power generation, and overcomes a series of defects in existing power generation technologies. Attached Figure Description

[0015] To illustrate the technical solution of the present invention in detail, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a distribution diagram of a special variable diameter shaft structure system for supporting large mechanical wheels, as described in Embodiment 1 of the present invention. Figure 2 Embodiment 2 of the present invention is a front view of the variable diameter shaft and the hub; Figure 3 This is a cross-sectional view of the bearing housing in Embodiment 3 of the present invention; Figure 4 The fourth embodiment of the present invention is a cross-sectional view of the variable diameter shaft, hub, bearing housing and input shaft.

[0017] The components in the above diagrams are replaced with their corresponding numbers: 1. Variable diameter shaft, 11. Intermediate shaft section, 12. Hub shaft connection section, 13. Hub connection section and bearing housing isolation section, 14. Bearing housing section, 141. Bearing section, 142. Transmission shaft section, 15. Starting power input section, 16. Maintaining rotating gear disk, 17. Disk teeth, 18. Keyway, 19. Mechanical wheel, 2. Support rod locking piece, 21. Equidistant support rod reinforcing ring, 22. Mechanical wheel outer ring, 9. Hub, 3. Outer edge of hub, 31. Equal interval setting of outer edge of hub, 32. Inner support of hub, 33. Bearing housing, 4. Bearing housing shell, 41. Bearing housing seat, 42. Inner bearing of bearing housing, 43. Outer bearing of bearing housing, 44. Lubricating oil circulation pump station device, 45. Mass point counterweight device, 5. Support rod, 7. Silencing ring, 8. Joint between mechanical wheel variable diameter shaft and gearbox, 10. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0019] The technical solutions provided by the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0020] Figure 1 This is a distribution diagram of a special variable diameter shaft structure system for supporting large mechanical wheels, as described in Embodiment 1 of the present invention. like Figure 1As shown in the figure, this diagram illustrates the distribution of the mechanical wheel structure system supported by a dedicated variable diameter shaft, illustrating the location and interconnections of various major components. Each increase in the diameter of the mechanical wheel leads to changes in the factors between m, h, v, g, r, and ω. Taking the variable diameter shaft 1 bearing a rotational load of hundreds of tons as an example, the intermediate shaft section 11 of the variable diameter shaft reaches a diameter of 700mm, gradually decreasing to 500mm in each section. It uses special steel with a shaft length of 6900mm, and the shaft body weight is greater than 20 tons. The variable diameter shaft 1, bearing a rotational load of hundreds of tons, is divided into the intermediate shaft section 11, the hub shaft connection section 12, the hub connection section and bearing housing isolation section 13, the bearing housing section 14, the bearing section 141, the bearing section 142, the mechanical wheel variable diameter shaft and gearbox energy transmission shaft section 15, or a separate starting power input section 16, or a large rotating gear disk 20 for the mechanical wheel. The shaft diameter is thicker in the middle, gradually decreasing in diameter, with the smallest diameter at the end of the transmission shaft section 15 or the starting power input section 16. The hub shaft connection section 12 uses... Damping components or planing the shaft section into a polygonal shape are used to solidify the hub 3; support rods 7 are set at equal intervals on the outer edge 31 of the hub, forming the hub and the mechanical wheel H-beam support rod or support rod 7 node to form the mechanical wheel 2 frame; three or more mass point counterweights 5 are evenly set between the mechanical wheel equidistant support rod reinforcement ring 22 and the mechanical wheel outer ring 9; the rotational dynamic load and the mechanical wheel body load are applied to the bearing housing 41 and the bearing housing 42 through the variable diameter shaft; in order to stabilize the mechanical wheel body and share the pressure, two sets of bearings of different models are used in the bearing housing 4, with the bearing 43 on the inner side of the bearing housing being larger than the bearing 44 on the outer side of the bearing housing; the bearings in the bearing housing 4 move by friction, and a lubricating oil circulation pump station device 45 is set to dissipate heat. The lubricating oil circulation channel is connected to the lubricating oil pump station device 45, and ISO VG 460 extreme pressure industrial gear oil is used for circulation lubrication, with a flow rate of 50L / min and a working pressure of 0.8MPa. The energy generated by the high-speed rotation of the mechanical wheel is transmitted through the mechanical wheel's variable diameter shaft and the gearbox joint 10, where a shrink-fit sleeve or a large spline connects to the gearbox. This example uses a multi-functional gearbox, which both inputs the mechanical wheel's starting energy into the gearbox to change from high speed to low speed for starting the mechanical wheel, and also changes the mechanical wheel's output energy from a low speed below 60 r / min to a high speed above 3000 r / min. The mechanical wheel's starting energy can also be input at the variable diameter shaft's starting power drive shaft section 16, connected to the output end of a reduction gearbox that changes speeds from above 3000 r / min to below 60 r / min. To reduce the impact of wind load on the bending force of the variable diameter shaft, and to mitigate the air resistance to the support rod and counterweight device during high-speed rotation of the mechanical wheel, as well as to enhance the bending force of the counterweight during rotation, a sound-absorbing ring 8 with a safety sealing function is fabricated. This ring is installed on the mechanical wheel, which has a narrow upper rim and a wide lower rim hub, thus completing the key distribution of the mechanical wheel structure system with dedicated variable diameter shaft support.

[0021] Figure 2Embodiment 2 of the present invention is a front view of the variable diameter shaft and the hub. like Figure 2 As shown, a hub 3 is installed on the hub shaft connection section of the variable diameter shaft 1. The hub 3 and the variable diameter shaft 1 are connected by a damping component or the section of the shaft is planed into a polygonal hub with a diameter of 2680mm. On the outer edge 31 of the hub ring with a circumference of πR, eighteen node surfaces 32 are set at equal intervals for the connection nodes between the hub and the H-shaped steel spokes of the mechanical wheel. The hub should maintain an isolation distance 13 from the adjacent bearing housing. Two bearings of different specifications are placed in the bearing housing section 14 of the variable diameter shaft 1. The energy starting and maintaining rotation input section 16 of the variable diameter shaft 1 is connected to the output end of the planetary reduction gearbox through a shrink sleeve or a large spline. Alternatively, a maintaining rotation gear disk 17 can be installed in the energy starting and maintaining rotation input section 16. Under the action of the keyway 19 and the flat key, it is fixed to the variable diameter shaft, and the gear disk at the output end of the planetary reduction gearbox meshes with the gear disk teeth 18 on the maintaining rotation gear disk 17 for transmission. Kinetic energy is output from the mechanical wheel variable diameter shaft transmission section 15.

[0022] Figure 3 This is a cross-sectional view of the bearing housing in Embodiment 3 of the present invention. like Figure 3 As shown, the variable diameter shaft 1 is divided into an intermediate shaft section 11, a hub shaft fixed connection section 12, a hub fixed connection section and bearing housing isolation section 13, a bearing housing section 14, a bearing section 141, a bearing section 142, and a mechanical wheel variable diameter shaft and gearbox energy transmission section 15. The load is applied to the bearing housing 4 of the bearing housing 41 and the bearing housing seat 42 through the bearings on the variable diameter shaft. In order to stabilize the mechanical wheel body and share the pressure, two sets of bearings of the same model or two sets of bearings of different models are used. When the models are different, the inner diameter and outer diameter of the two sets of bearings are different, with the bearing 43 on the inner side of the shaft being larger than the bearing 44 on the outer side of the shaft. The bearings in the bearing housing 4 generate heat due to friction, and a lubricating oil circulation pump station device 45 is set to dissipate the heat.

[0023] Figure 4 This is a cross-sectional view of the variable diameter shaft, hub, bearing housing, and input shaft in Embodiment 4 of the present invention. like Figure 4 As shown, the variable diameter shaft 1 is divided into an intermediate shaft section 11, a hub shaft fixing section 12 for fixing the hub, a hub 3 fixing section and a bearing housing reserved isolation section 13, a bearing housing section 14 on which the bearing housing 4 is installed, and a mechanical wheel variable diameter shaft and gearbox energy transmission section 15 for outputting kinetic energy; a mechanical wheel rotation starting and maintaining energy input shaft section 16, the input shaft section is equipped with a large gear disk, the large gear disk is converted from high speed 3000~5000r / min to low speed 20~60r / min required by the variable diameter shaft to the output gear of the reduction gearbox meshing transmission, or is connected by a giant shrink sleeve or a large spline end to the output end of the reduction gearbox, for starting the mechanical wheel and maintaining the rotation of the mechanical wheel.

Claims

1. A variable diameter shaft specifically designed for supporting large mechanical wheels, characterized in that, A variable-diameter shaft blank is forged from high-strength steel with a yield strength ≥690MPa. After passing flaw detection, the variable-diameter shaft blank is machined into a series of interconnected intermediate shaft sections, hub-fixed sections, isolation sections, bearing housing sections, and energy transmission shaft sections. The intermediate shaft section, which bears the greatest bending force, has the largest diameter, gradually decreasing towards both ends, with the smallest diameter at both ends and the energy transmission shaft section. The hub-fixed section uses keyways and flat keys to fix polygonal hubs, which form the fulcrum of the mechanical wheel support frame. Two sets of bearings are installed in the bearing housings at both ends of the variable-diameter shaft. The energy transmission shaft section is divided into an energy input transmission shaft section for maintaining the uniform rotation of the mechanical wheel and an energy output transmission shaft section for the mechanical wheel. A large gear disk or shrink sleeve is installed in the rotational energy input transmission shaft section. The large gear disk is driven by gear meshing of an energy input reduction gearbox. The mechanical wheel energy output transmission shaft section is connected to a speed-increasing gearbox through a shrink sleeve or a large spline.

2. The variable diameter shaft for bearing large mechanical wheels according to claim 1, characterized in that, The total length of the variable diameter shaft is 6000mm to 8000mm, the diameter of the intermediate shaft section is 600mm to 800mm, and the diameter of the energy transmission shaft section is 500mm to 600mm.

3. The variable diameter shaft for bearing large mechanical wheels according to claim 1, characterized in that, The variable diameter shaft can withstand a load of over 100 tons and has a rotation speed of 20 r / min to 60 r / min.

4. The variable diameter shaft for bearing large mechanical wheels according to claim 1, characterized in that, The middle section of the hub on both sides of the variable diameter shaft is the center of a large mechanical wheel, with a length and width greater than 2500mm.

5. A special variable diameter shaft for bearing large mechanical wheels according to claim 1, characterized in that, The inner diameter of the hub is located at the hub shaft connection section; the outer edge is formed by eighteen equilateral polygons; each equilateral polygon constitutes a support node for a large mechanical wheel; the polygonal hubs are symmetrically distributed on both sides of the intermediate shaft section; the variable diameter shaft hub connection section is secured by a combination of keyways and flat keys or by planing the shaft section into a polygonal hub; the hub rotates together with the variable diameter shaft.

6. A special variable diameter shaft for supporting large mechanical wheels according to claim 1, characterized in that, The bearing housing is formed by casting or welding. Two sets of bearings are installed at the bearing housings at both ends of the variable diameter shaft. The inner and outer diameters of the two sets of bearings are different, with the bearings on the inner side of the bearing housing being larger than those on the outer side.

7. A special variable diameter shaft for bearing large mechanical wheels according to claim 1, characterized in that, The variable diameter shaft input energy transmission section is fitted with a shrink sleeve and connected to a reduction planetary gearbox; the reduction planetary gearbox reduces the input high-speed power (3000r / min~5000r / min) to 20r / min~60r / min before transmitting it to the variable diameter shaft.

8. A special variable diameter shaft for bearing large mechanical wheels according to claim 1, characterized in that, The bearing housing is provided with a lubricating oil circulation channel for bearing lubrication and bearing cooling; the lubricating oil circulation channel is connected to a lubricating oil pump station device.

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