Low-stress flexible connection structure of flywheel rotor and rotating shaft

Abstract

The invention provides a flywheel rotor and rotating shaft low-stress flexible connection structure, and relates to the technical field of flywheels, the flywheel rotor and rotating shaft low-stress flexible connection structure comprises an arc tenon, an elastic buffer gasket, an arc mortise, a flywheel rotor, an axial positioning ring, a rotating shaft, a gradient material transition ring, a flexible mortise and tenon connection assembly and an elastic buffer gasket; the elastic buffer gasket is embedded between the arc-shaped tenon and the elastic buffer gasket; the elastic buffer gasket is attached to the surface of the rotating shaft; the gradient material transition ring is connected with the rotating shaft through a flexible mortise and tenon joint; the gradient material transition ring is arranged between the inner hole of the flywheel rotor and the rotating shaft; the arc-shaped tenons are evenly distributed on the outer circle surface of the rotating shaft in the circumferential direction. The arc-shaped mortises are uniformly distributed on the surface of an inner hole of the gradient material transition ring along the circumferential direction and correspond to the arc-shaped tenons; the transition ring, the flywheel rotor, the axial positioning ring and the rotating shaft are coaxial; the flexible mortise and tenon joint assembly is used for connecting the gradient material transition ring and the rotating shaft; and the elastic buffer gasket is embedded between the matching surfaces of the flexible mortise and tenon joint components.

Description

Technical Field

[0001] This invention relates to the field of flywheel technology, and in particular to a low-stress flexible connection structure between a flywheel rotor and a shaft. Background Technology

[0002] The core performance of flywheel energy storage systems highly depends on the connection structure between the rotor and the shaft. As a key interface for kinetic energy transfer and high-speed rotation support, this structure must simultaneously meet three core requirements: high coaxiality, low stress concentration, and long fatigue life. However, current connection solutions in the industry have unresolved key technical defects, which have become a major bottleneck restricting the upgrading of flywheel energy storage devices to higher speeds and longer lifespans. Therefore, it is urgent to optimize the design of this connection structure.

[0003] Currently, the mainstream connection solutions between flywheel rotors and shafts fall into two main categories: one is a rigid interference fit connection, achieved through hot or cold fitting methods, to meet the coaxiality and torque transmission stiffness requirements of high-speed rotation scenarios; the other is a key or spline connection, combined with a transition fit, suitable for medium- and low-speed or low-power scenarios. Furthermore, existing industry improvements largely focus on material upgrades, parameter optimization, and active compensation solutions relying on sensors and processors.

[0004] However, the interference fit of existing technologies can lead to uneven preload stress in the assembly, which can easily cause fatigue failure; keyed connections can generate stress singularities due to the sharp transition of the keyway, and the fit clearance will increase with wear, resulting in sudden changes in the properties of heterogeneous materials, and fatigue damage is likely to occur at the connection. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a low-stress flexible connection structure between a flywheel rotor and a shaft, which can solve the problem that interference fits in the prior art can lead to uneven preload stress, easily causing fatigue failure. Furthermore, keyed connections suffer from stress singularities due to sharp keyway transitions, and the fit clearance widens with wear, leading to abrupt changes in the properties of dissimilar materials and making the connection prone to fatigue damage.

[0006] In a first aspect, a low-stress flexible connection structure between a flywheel rotor and a shaft is proposed, comprising: an arc-shaped tenon, an elastic buffer pad, an arc-shaped tenon groove, a flywheel rotor, an axial positioning ring, a shaft, a gradient material transition ring, a flexible tenon-and-mortise connection assembly, and an elastic buffer pad. The elastic buffer pad is embedded between the arc-shaped tenon and the elastic buffer pad; The elastic buffer pad is in contact with the surface of the rotating shaft; The gradient material transition ring and the rotating shaft are connected by a flexible tenon and mortise joint; The gradient material transition ring is disposed between the inner hole of the flywheel rotor and the shaft; The arc-shaped tenons are evenly distributed circumferentially on the outer circular surface of the rotating shaft; The arc-shaped tenons are evenly distributed circumferentially on the inner surface of the gradient material transition ring, and the arc-shaped tenons correspond to the arc-shaped tenons. The transition ring, the flywheel rotor, the axial positioning ring, and the rotating shaft are coaxial; The flexible tenon-and-mortise connection assembly is used to connect the gradient material transition ring and the rotating shaft; The elastic buffer pad is embedded between the mating surfaces of the flexible tenon and mortise connection assembly; The passive design of the gradient material transition ring, the flexible tenon and mortise connection assembly, and the elastic buffer pad achieves a low-stress connection between the flywheel rotor and the shaft.

[0007] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: In this embodiment of the invention, the flywheel rotor with flexible connection solves the problem of uneven preload stress at the connection point under rated speed, thus extending the fatigue life of the device. Furthermore, the gradient material transition ring eliminates abrupt changes in the properties of dissimilar materials, and the arc transition and elastic gasket buffer of the flexible tenon-and-mortise connection assembly significantly reduce the stress concentration factor, thereby minimizing fatigue damage at the connection point. Attached Figure Description

[0008] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0009] Figure 1 This is a schematic diagram of a low-stress flexible connection structure between a flywheel rotor and a shaft provided in an embodiment of the present invention.

[0010] Figure 2 This is a partial structural schematic diagram of a flexible tenon-and-mortise connection assembly for a low-stress flexible connection structure between a flywheel rotor and a shaft, provided in an embodiment of the present invention.

[0011] Explanation of reference numerals in the attached drawings: 1-arc tenon; 2-elastic buffer pad; 3-arc tenon groove; 4-flywheel rotor; 5-axial positioning ring; 6-rotor shaft; 7-gradient material transition ring; 8-flexible tenon and mortise connection assembly; 9-elastic buffer pad. Detailed Implementation

[0012] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0013] Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts disclosed in this invention.

[0014] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention.

[0015] Reference manual attached Figures 1 to 2 The present invention provides a low-stress flexible connection structure for a flywheel rotor and a rotating shaft, comprising: an arc-shaped tenon 1, an elastic buffer pad 2, an arc-shaped tenon groove 3, a flywheel rotor 4, an axial positioning ring 5, a rotating shaft 6, a gradient material transition ring 7, a flexible tenon-and-mortise connection assembly 8, and an elastic buffer pad 9.

[0016] The elastic buffer pad 2 is embedded between the arc-shaped tenon 1 and the elastic buffer pad 2.

[0017] The elastic buffer pad 2 is attached to the surface of the rotating shaft 6.

[0018] The gradient material transition ring 7 and the rotating shaft 6 are connected by a flexible tenon and mortise joint.

[0019] A gradient material transition ring 7 is disposed between the inner hole of the flywheel rotor 4 and the shaft 6.

[0020] The arc-shaped tenons 1 are evenly distributed circumferentially on the outer circular surface of the rotating shaft 6.

[0021] The arc-shaped tenon grooves 3 are evenly distributed circumferentially on the inner surface of the gradient material transition ring 7, and the arc-shaped tenon grooves 3 correspond to the arc-shaped tenons 1.

[0022] The transition ring 7, flywheel rotor 4, axial positioning ring 5, and rotating shaft 6 are coaxial.

[0023] The flexible tenon and mortise connection component 8 is used to connect the gradient material transition ring 7 and the pivot 6.

[0024] The elastic buffer pad 9 is embedded between the mating surfaces of the flexible tenon and mortise connection component 8.

[0025] The flywheel rotor 4 and the shaft 6 are connected with low stress through the passive design of gradient material transition ring 7, flexible tenon and mortise connection component 8 and elastic buffer pad 9.

[0026] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: In this embodiment of the invention, the flywheel rotor 4 with flexible connection solves the problem of uneven preload stress at the connection point at the rated speed, thus extending the fatigue life of the device. Furthermore, the gradient material transition ring 7 eliminates abrupt changes in the properties of dissimilar materials, and the arc-shaped transition of the flexible tenon-and-mortise connection assembly 8, combined with the elastic gasket buffer 2, significantly reduces the stress concentration factor and minimizes fatigue damage at the connection point.

[0027] In one possible implementation, the inner side of the gradient material transition ring 7 and the rotating shaft 6 are both made of titanium alloy.

[0028] In this embodiment of the invention, the inner side of the gradient material transition ring 7 and the rotating shaft 6 are both made of titanium alloy, which can achieve complete material compatibility between the two materials, avoid the performance abrupt interface caused by the connection of heterogeneous materials, reduce stress concentration caused by the difference in elastic modulus, and adapt to the strong centrifugal force working conditions of high-speed rotation, improve the assembly fit and long-term operational reliability of the connection structure, and extend the fatigue life of the overall connection parts.

[0029] In one possible implementation, both the outer side of the gradient material transition ring 7 and the flywheel rotor 4 are made of carbon fiber reinforced resin matrix composite material.

[0030] In this embodiment of the invention, both the outer side of the gradient material transition ring 7 and the flywheel rotor 4 are made of carbon fiber reinforced resin matrix composite material, which can achieve precise matching of the two materials, eliminate the performance abrupt problem of heterogeneous material connection, reduce stress concentration caused by the difference in elastic modulus, and at the same time rely on the lightweight and high strength characteristics of the composite material to adapt to the strong centrifugal force working condition of high speed rotation of the flywheel, improve the fit of the connection interface and torque transmission stability, and further extend the fatigue life of the connection structure.

[0031] In one possible implementation, the intermediate layer of the gradient material transition ring 7 is made of titanium alloy-carbon fiber composite material.

[0032] Specifically, by using a composite process of powder metallurgy and fiber weaving, the titanium alloy content is linearly reduced from 100% on the inside to 0% on the outside, while the carbon fiber content is linearly increased from 0% on the inside to 100% on the outside. This eliminates the abrupt performance interface of traditional heterogeneous material connections and avoids stress concentration caused by differences in the elastic modulus of the materials.

[0033] In this embodiment of the invention, the intermediate layer of the gradient material transition ring 7 is made of titanium alloy-carbon fiber composite material. The composition is linearly transitioned through powder metallurgy and fiber weaving composite process, which completely eliminates the performance abrupt interface of traditional heterogeneous material connection, effectively avoids stress concentration caused by the difference in elastic modulus, greatly improves the mechanical adaptability and high-speed operation stability of the connection structure, and significantly extends the fatigue life of the connection part.

[0034] In one possible implementation, the inclination angles of the two sides of the arc-shaped tenon 3 are consistent with the inclination angles of the arc-shaped tenon 1.

[0035] In this embodiment of the invention, the two sides of the arc-shaped tenon 3 are at the same angle as the arc-shaped tenon 1, which can ensure that the mating surfaces of the two are completely in contact and the force is evenly distributed, avoid local stress singularities, improve the smoothness and stability of torque transmission, reduce impact friction and wear during high-speed rotation, further reduce the risk of stress concentration, and extend the fatigue life of the connection structure.

[0036] In one possible implementation, the bottom of the arc-shaped tenon 3 is designed with an arc transition.

[0037] In this embodiment of the invention, the bottom of the arc-shaped tenon groove 3 is designed with an arc transition, which eliminates the defects of traditional right angles or small-radius arcs that are prone to stress singularities, making the transmission of centrifugal force and torque during high-speed rotation more uniform, effectively reducing local stress concentration, reducing impact damage and wear on mating surfaces, and significantly improving the operational stability and long-term fatigue life of the connection structure.

[0038] In one possible implementation, the elastic buffer pad 2 is made of beryllium copper alloy.

[0039] Specifically, an elastic buffer pad 2 is embedded between the mating surfaces of each set of tenons 1 and mortises 3.

[0040] In this embodiment of the invention, the elastic buffer pad 2 is made of beryllium copper alloy and embedded in the mating surface of the tenon 1 and the mortise 3. It can effectively buffer the instantaneous stress during high-speed rotation, compensate for minor errors in the tenon and mortise machining, reduce friction and wear on the mating surface, and prevent stress from being directly transmitted to the connection interface, thereby greatly improving the adaptability, stability and long-term fatigue life of the connection structure.

[0041] In one possible implementation, the elastic buffer pad 2 and the arc tenon 1 have the same mating surface and are formed by laser cutting.

[0042] Specifically, the elastic buffer pad 2 is slightly compressed during assembly, which can compensate for minor errors in the tenon and mortise machining, and also buffer the instantaneous stress generated by the centrifugal force of the rotor and the torque transmission of the shaft during high-speed rotation, preventing stress from being directly transmitted to the connection interface. The surface of the buffer pad 2 is coated with polytetrafluoroethylene to reduce the coefficient of friction of the tenon and mortise mating surfaces during high-speed operation and reduce wear.

[0043] In this embodiment of the invention, the elastic buffer pad 2 is laser-cut and its mating surface is completely consistent with that of the arc tenon 1, which can achieve a tight fit between the two. The slight compression during assembly can accurately compensate for the small errors in the tenon and mortise machining. The polytetrafluoroethylene coating on the surface effectively reduces the coefficient of friction during high-speed operation, which not only buffers the instantaneous stress generated by the centrifugal force of the rotor and the torque of the shaft, and avoids the stress being directly transmitted to the connection interface, but also reduces the wear of the mating surface, significantly improving the adaptability, stability and fatigue life of the connection structure.

[0044] In one possible implementation, the tenon of the gradient material transition ring 7 is aligned with the tenon of the rotating shaft 6, and an axial thrust is applied to complete the initial assembly, while the elastic buffer pad 2 of the tenon-and-mortise mating surface is in a slightly compressed state.

[0045] Specifically, at room temperature, the elastic buffer pad 2 is attached to the tenon surface of the rotating shaft 6 to ensure no wrinkles. A flexible tenon-and-mortise connection is used between the gradient material transition ring 7 and the rotating shaft 6, replacing the traditional interference fit or key connection. Six sets of arc-shaped tenons 1 are uniformly machined circumferentially on the outer surface of the rotating shaft 6. The axial length of the arc-shaped tenons 1 is consistent with that of the transition ring 7, and the two sides of the arc-shaped tenons 1 are designed with an inclination angle of 15° to 20°, forming a flexible mating surface that is wider on the outside and narrower on the inside. Six sets of arc-shaped tenons 3 are correspondingly machined on the inner surface of the gradient material transition ring 7. The arc-shaped tenons 3 match the tenons 1, ensuring a minimal fit clearance.

[0046] In this embodiment of the invention, by simplifying the process and avoiding material damage caused by extreme temperatures, the flexible mortise and tenon connection is equipped with 6 sets of circumferentially evenly distributed arc-shaped tenons 3 and mortises 1, combined with a flexible mating surface with an inclination angle of 15°-20° and a micro-gap design, plus the slight compression state of the elastic buffer pad. This can not only accurately compensate for processing errors and uniformly transmit torque, but also buffer instantaneous stress and avoid stress concentration, and eliminate the loosening risk of traditional connections, thus greatly improving assembly efficiency and the long-term operational stability of the connection structure.

[0047] In one possible implementation, the shaft 6 of the assembled gradient material transition ring 7 is inserted into the inner hole of the flywheel rotor 4, with the inner hole of the flywheel rotor 4 and the outer side of the gradient material transition ring 7 having a transition fit. The flywheel rotor 4, the gradient material transition ring 7 and the shaft 6 are axially fixed by the axial positioning ring 5 to complete the overall assembly.

[0048] In this embodiment of the invention, a transition fit design is adopted to avoid the additional stress generated by rigid assembly. The axial positioning ring is used to achieve a stable lock of the flywheel rotor 4, the transition ring 7 and the shaft 6, which not only ensures high coaxiality but also prevents loosening and displacement during operation. At the same time, it simplifies the overall assembly process, adapts to the flexible structure design mentioned above, and further improves the operational stability and long-term service life of the connection system.

[0049] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the preferred embodiments, while those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the protection scope of the present invention.

Claims

1. A low-stress flexible connection structure between a flywheel rotor and a shaft, characterized in that, include: Arc-shaped tenon (1), elastic buffer pad (2), arc-shaped mortise (3), flywheel rotor (4), axial positioning ring (5), rotating shaft (6), gradient material transition ring (7), flexible tenon and mortise connection assembly (8), and elastic buffer pad (9); The elastic buffer pad (2) is embedded between the arc-shaped tenon (1) and the elastic buffer pad (2); The elastic buffer pad (2) is in contact with the surface of the rotating shaft (6); The gradient material transition ring (7) and the rotating shaft (6) are connected by a flexible tenon and mortise joint; The gradient material transition ring (7) is disposed between the inner hole of the flywheel rotor (4) and the shaft (6); The arc-shaped tenons (1) are evenly distributed circumferentially on the outer circular surface of the rotating shaft (6); The arc-shaped tenon (3) is evenly distributed circumferentially on the inner hole surface of the gradient material transition ring (7), and the arc-shaped tenon (3) corresponds to the arc-shaped tenon (1); The transition ring (7), the flywheel rotor (4), the axial positioning ring (5), and the rotating shaft (6) are coaxial; The flexible tenon and mortise connection assembly (8) is used to connect the gradient material transition ring (7) and the rotating shaft (6). The elastic buffer pad (9) is embedded between the mating surfaces of the flexible tenon and mortise connection assembly (8); Through the passive design of the gradient material transition ring (7), the flexible tenon connection assembly (8) and the elastic buffer pad (9), the flywheel rotor (4) and the shaft (6) are connected with low stress.

2. The low-stress flexible connection structure between the flywheel rotor and the shaft according to claim 1, characterized in that, The inner side of the gradient material transition ring (7) and the rotating shaft (6) are both made of titanium alloy.

3. The low-stress flexible connection structure between the flywheel rotor and the shaft according to claim 1, characterized in that, The outer side of the gradient material transition ring (7) and the flywheel rotor (4) are both made of carbon fiber reinforced resin matrix composite material.

4. The low-stress flexible connection structure between the flywheel rotor and the shaft according to claim 1, characterized in that, The intermediate layer of the gradient material transition ring (7) is made of titanium alloy-carbon fiber composite material.

5. The low-stress flexible connection structure between the flywheel rotor and the shaft according to claim 1, characterized in that, The inclination angles of the two sides of the arc-shaped tenon (3) are consistent with the inclination angles of the arc-shaped tenon (1).

6. The low-stress flexible connection structure between the flywheel rotor and the shaft according to claim 1, characterized in that, The bottom of the arc-shaped tenon (3) is designed with an arc transition.

7. The low-stress flexible connection structure between the flywheel rotor and the shaft according to claim 1, characterized in that, The elastic buffer pad (2) is made of beryllium copper alloy.

8. The low-stress flexible connection structure between the flywheel rotor and the shaft according to claim 1, characterized in that, The elastic buffer pad (2) and the arc tenon (1) have the same mating surface and are formed by laser cutting.

9. The low-stress flexible connection structure between the flywheel rotor and the shaft according to claim 1, characterized in that, The tenon groove of the gradient material transition ring (7) is aligned with the tenon of the rotating shaft (6), and an axial thrust is applied to complete the initial assembly. The elastic buffer pad (2) of the tenon-mortise mating surface is in a slightly compressed state.

10. The low-stress flexible connection structure between the flywheel rotor and the shaft according to claim 1, characterized in that, The rotating shaft (6) of the assembled gradient material transition ring (7) is inserted into the inner hole of the flywheel rotor (4). The inner hole of the flywheel rotor (4) and the outer side of the gradient material transition ring (7) are in transition fit. The flywheel rotor (4), the gradient material transition ring (7) and the rotating shaft (6) are axially fixed by the axial positioning ring (5) to complete the overall assembly.

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