Serpentine spring, transmission assembly and coupler

Abstract

According to the serpentine spring, the transmission assembly and the coupler, when the serpentine spring is in the stressed state, the section shape of the surface of the deformation arm of the serpentine spring is in the variable-curvature curve shape, buffering on impact stress is enhanced, stress concentration is reduced, the durability of the serpentine spring is improved, and the service life of the serpentine spring is prolonged. And the reliability of the transmission assembly and the coupling is improved.

Description

Technical Field

[0001] The present application relates to the field of serpentine springs, and more specifically, to a serpentine spring, a transmission assembly and a coupling. Background Art

[0002] The serpentine spring coupling is a commonly used shaft connection transmission component. It mainly transmits torque through serpentine spring sheets. It is suitable for connecting two coaxial transmission shaft systems and has certain compensation for the relative offset of the two shafts and vibration reduction and buffering performance. The serpentine spring sheet is embedded in the tooth grooves of the two half couplings to achieve the connection between the active shaft and the driven shaft. During operation, the axial force of the active end tooth surface on the serpentine spring drives the driven end to transmit torque and avoid resonance. The elastic variable generated by the spring sheet when transmitting torque enables the mechanical system to obtain a better vibration reduction effect.

[0003] The service life of the serpentine spring is very important. When working under the impact conditions of frequent forward and reverse starting, if the serpentine spring is of poor quality, fatigue cracks will appear on the serpentine spring quickly. Under the repeated impact load, the cracks will expand and break quickly. The tooth surface design of the active end and the driven end affects the matching of the active shaft, the transmission shaft and the serpentine spring, which in turn affects the service life of the serpentine spring.

[0004] The tooth surface of the serpentine spring coupling is usually a linear tooth surface. Under normal load, the distance between the serpentine spring and the tooth contact point does not change with the change of the spring deformation, so the stiffness remains unchanged. This design allows the relative rotation angle of the two half couplings to maintain a linear relationship with the transmitted torque, which is a constant stiffness serpentine spring coupling. The straight tooth shape is easy to process and has low cost, but it is only suitable for working conditions with small changes in the transmitted torque. When the serpentine spring deforms along the straight tooth surface, the stress on the serpentine spring is more concentrated, and the local impact force is large, which affects the service life of the serpentine spring. During long-term operation, the tooth surface may wear, especially under high load or frequent start-up conditions, which may cause tooth surface fatigue, thereby affecting the reliability of the coupling.

[0005] The tooth surface wear problem of the coupling is usually solved by increasing the hardness of the tooth surface, but this will increase the brittleness of the tooth surface and make it easy to break under impact load. In addition, some couplings use simple lubrication methods, such as oil bath lubrication. Although it can reduce tooth surface friction, the lubrication effect is limited and cannot effectively reduce tooth surface wear. Some couplings use traditional materials, such as ordinary carbon steel or low alloy steel. These materials have poor wear resistance and fatigue resistance, resulting in a shorter coupling life. In terms of gear design, the gear parameter selection of traditional couplings is not reasonable enough. For example, the selection of module and number of teeth does not fully consider the actual working conditions, resulting in insufficient gear load capacity and easy wear and damage. Summary of the invention

[0006] One advantage of the present application is that it provides a serpentine spring, a transmission assembly and a coupling. After the serpentine spring is deformed, the cross-sectional shape of its deformation arm conforms to the variable curvature curve characteristics, which can reduce stress concentration, reduce stress impact and increase service life.

[0007] Another advantage of the present application is that it provides a serpentine spring, a transmission assembly and a coupling, wherein the cross-sectional shape of the deformation arm of the serpentine spring conforms to the logarithmic curve characteristics, and the logarithmic curve provides a gradually changing slope, so that the force can be smoothly and gradually distributed along the length of the serpentine spring, further reducing stress concentration, reducing impact, and increasing the service life of the serpentine spring.

[0008] Another advantage of the present application is that it provides a serpentine spring, a transmission assembly and a coupling, wherein the tooth surface of the transmission element of the transmission assembly is a curved surface, so as to cause the serpentine spring to deform along the curved surface, increase the contact area between the serpentine spring and the transmission assembly, reduce stress concentration, and improve transmission efficiency.

[0009] Another advantage of the present application is that it provides a serpentine spring, a transmission assembly and a coupling. By optimizing the shape of the tooth surface of the transmission assembly, the performance of the serpentine spring can be optimized and the working efficiency of the coupling can be improved. The cost is low and the applicability is high.

[0010] According to one aspect of the present application, the present application provides a serpentine spring, comprising:

[0011] A plurality of first bending arms, a plurality of deformable arms and a plurality of second bending arms, each of the first bending arms, each of the deformable arms and each of the second bending arms are connected in sequence, wherein when the serpentine spring is in a stressed state, the cross-sectional shape of the surface of the deformable arm presents a variable curvature curve.

[0012] According to one embodiment of the present application, the serpentine spring includes a plurality of first deformation units and a plurality of second deformation units, each of the first deformation units and each of the second deformation units are connected in sequence and arranged in a centrally symmetrical manner, and one of the first deformation unit and the second deformation unit is suitable for being mounted on a main transmission element of the coupling, and the other is suitable for being mounted on a slave transmission element of the coupling.

[0013] According to one embodiment of the present application, the first deformation unit includes the first bending arm and two first deformation arms, and the first deformation arm, the first bending arm and another first deformation arm are connected in sequence to form a U-shape, and the second deformation unit includes the second bending arm and two second deformation arms, and the second deformation arm, the second bending arm and another second deformation arm are connected in sequence to form a U-shape.

[0014] According to one embodiment of the present application, the first deformable arm and the second deformable arm are connected to form the deformable arm, wherein when the serpentine spring is in a stressed state, the cross-sectional shape of the first deformable arm and the second deformable arm presents a variable curvature curve form such as a logarithmic curve.

[0015] According to an embodiment of the present application, the first deformation unit and the second deformation unit are centrally symmetric.

[0016] According to one aspect of the present application, the present application provides a transmission assembly suitable for a coupling, comprising:

[0017] At least two transmission elements, the transmission elements are coaxially connected, wherein the transmission element comprises a plurality of teeth distributed at intervals, and the cross-sectional shape of the tooth surface conforms to the variable curvature curve characteristic; and

[0018] A serpentine spring, wherein the serpentine spring is sleeved on the transmission element to transmit between the transmission elements, wherein the serpentine spring includes a deformable arm, a portion of which is embedded between the teeth and deformed along the tooth surface so that the cross-sectional shape of the deformable arm presents a variable curvature curve characteristic such as a logarithmic curve characteristic.

[0019] According to one embodiment of the present application, the transmission element includes a main transmission element and a slave transmission element, the main transmission element and the slave transmission element are coaxially connected, and the serpentine spring is sleeved between the main transmission element and the slave transmission element to transmit torque.

[0020] According to one embodiment of the present application, the main transmission element includes a plurality of active teeth distributed around the circumference, an active tooth groove is formed between the active teeth, and each active tooth has two active tooth surfaces facing opposite directions along the circumferential direction, wherein the cross-sectional shape of the active tooth surface conforms to a variable curvature curve characteristic such as a logarithmic curve characteristic.

[0021] According to one embodiment of the present application, the driven transmission element includes a plurality of driven teeth distributed around a circle along the circumferential direction, a driven tooth groove is formed between each of the driven teeth, and each of the driven teeth has two driven tooth surfaces facing opposite directions along the circumferential direction, wherein the cross-sectional shape of the driven tooth surface conforms to a variable curvature curve characteristic such as a logarithmic curve characteristic.

[0022] According to one aspect of the present application, the present application provides a coupling, comprising the aforementioned transmission assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present application, rather than limiting the present application.

[0024] Figure 1 It is a schematic diagram of a serpentine spring in an unstressed state according to an embodiment of the present application.

[0025] Figure 2 It is a schematic diagram of a serpentine spring in a stressed state according to an embodiment of the present application.

[0026] Figure 3 is a schematic diagram of a transmission assembly according to an embodiment of the present application.

[0027] Figure 4 It is a schematic diagram and a partially enlarged diagram of a transmission component when not working according to an embodiment of the present application.

[0028] Figure 5 is a schematic diagram of a transmission element of a transmission assembly according to an embodiment of the present application.

[0029] Figure 6 It is a schematic diagram of a transmission component in operation according to an embodiment of the present application.

[0030] Figure 7 It is a schematic diagram and a partially enlarged diagram of a transmission component in operation according to an embodiment of the present application.

[0031] Figure 8 It is a schematic diagram of the design of a variable curvature curve of a serpentine spring according to an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings showing multiple embodiments of the present application. It should be understood that the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments described in the present application, all other embodiments obtained by ordinary technicians in this field without spending creative work will fall within the scope of protection of the present application.

[0033] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those generally understood by technicians in the technical field of this application; the terms used in the specification of the application are only for the purpose of describing specific implementation methods, and are not intended to limit this application; the terms "including", "comprising", "having", "having", "containing", "including", etc. in the specification and claims of this application and the above-mentioned figure description are open-ended words. Therefore, "including", "comprising", "having" is a method or device with one or more steps or elements, for example, which has one or more steps or elements, but is not limited to having only these one or more elements. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned figures are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, the meaning of "multiple" is two or more.

[0034] In the description of the present application, it should be understood that the terms "center", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0035] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0037] As mentioned above, it should be emphasized that when the term "includes / comprising" is used in this specification, it is used to clearly indicate the presence of the features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps, components or groups of features, integers, steps, components. As used in this application, the singular forms "a", "an" and "the" also include plural forms, unless the context clearly indicates otherwise.

[0038] The words "a" and "an" in this specification may mean one, but may also be consistent with the meaning of "at least one" or "one or more". The term "about" generally means plus or minus 10% of the mentioned value, or more specifically plus or minus 5%. The term "or" used in the claims means "and / or" unless it is clearly stated that it refers to only alternative solutions.

[0039] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0040] Combined with the accompanying drawings Figures 1 to 7 As shown in the figure, the present application provides a serpentine spring 100, a transmission assembly 200 and a coupling 300, wherein the serpentine spring 100 is suitable for being embedded in the transmission assembly 200 of the coupling 300 for transmission. The serpentine spring 100 transmits power through elastic deformation, and the serpentine spring 100 is formed around a circle.

[0041] The serpentine spring 100 includes a plurality of first deformation units 101 and a plurality of second deformation units 102, wherein the plurality of first deformation units 101 and the plurality of second deformation units 102 are arranged alternately in sequence, and the adjacent first deformation units 101 and the second deformation units 102 are arranged symmetrically with the connection between the first deformation unit 101 and the second deformation unit 102 as the central symmetry point. Further, the plurality of first deformation units 101 and the plurality of second deformation units 102 are integrally formed, that is, the serpentine spring 100 is integrally formed.

[0042] The first deformation unit 101 and the second deformation unit 102 are both U-shaped, and the U-shaped openings of the first deformation unit 101 and the second deformation unit 102 face opposite directions. The first deformation unit 101 has two first deformation arms 1011 and one first bending arm 1012, and the first deformation arm 1011, the first bending arm 1012 and another first deformation arm 1011 are connected in sequence to form a U shape. The second deformation unit 102 has two second deformation arms 1021 and one second bending arm 1022, and the second deformation arm 1021, the second bending arm 1022 and another second deformation arm 1021 are connected in sequence to form a U shape.

[0043] A first deformable arm 1011 of the first deformable unit 101 is connected to a second deformable arm 1021 of the adjacent second deformable unit 102 to form a deformable arm 11. Adjacent deformable arms 11 are connected via the first bending arm 1012 or the second bending arm 1022. That is, the serpentine spring 100 includes the deformable arm 11, the first bending arm 1012 and the second bending arm 1022, and the first bending arm 1012, the deformable arm 11 and the second bending arm 1022 are connected in sequence.

[0044] The serpentine spring 100 has a force-bearing surface 110, and the force-bearing surface 110 is defined as the surface where the serpentine spring 100 contacts the transmission assembly 200 of the coupling 300. The first deformable arm 1011 and the second deformable arm 1021 have an inner surface and an outer surface, respectively. The force-bearing surfaces 110 of the first deformable arm 1011 and the second deformable arm 1021 connected to each other face oppositely. The outer surface of the first deformable arm 1011 and the inner surface of the second deformable arm 1021 of a part of the deformable arm 11 are the force-bearing surface 110, and the inner surface of the first deformable arm 1011 and the outer surface of the second deformable arm 1021 of a part of the deformable arm 11 are the force-bearing surface 110.

[0045] When the serpentine spring 100 is in a stressed state, the first deformable arm 1011 and the second deformable arm 1021 of the deformable arm 11 are deformed in opposite directions, so that the force-bearing surface 110 of the first deformable arm 1011 and the force-bearing surface 110 of the second deformable arm 1021 are curved surfaces. That is to say, when the serpentine spring 100 is in a stressed state, the cross-sectional shape of its deformable arm 11 presents a curved characteristic.

[0046] That is to say, when the serpentine spring 100 provided by the present application is under stress, the cross-sectional shape of the deformable arm 11 presents a curved shape. With such a design, the contact area between the serpentine spring 100 and the transmission assembly 200 is larger than that of a straight contact, the contact strength and stability are improved, the stress concentration is reduced, the force distribution is more uniform, the buffering of the impact stress is enhanced, and the load is avoided from being too concentrated, so as to prevent the serpentine spring 100 from being damaged, reduce the wear of the serpentine spring 100, and reduce the loss of force transmission, reduce friction, and thus improve the transmission efficiency.

[0047] Furthermore, the curve characteristic of the cross-sectional shape of the deformable arm 11 is a variable curvature curve. Such a design enables the serpentine spring 100 to absorb and disperse stress more effectively when transmitting power. The curvature of the variable curvature curve fluctuates, and this characteristic makes the curvature value of the curve different at different points, thereby affecting the direction and magnitude of the normal force at each point on the curve. The change in curvature can create a smoother force transition, thereby reducing local stress peaks, especially under high load conditions. By adjusting the curvature, the serpentine spring 100 can provide a better response effect to the driving force.

[0048] The present application also provides a transmission assembly 200, the transmission assembly 200 includes at least two transmission elements 21 connected to each other, and the two transmission elements 21 are coaxially connected and can be driven. The transmission element 21 rotates around the rotation axis. The axial direction described in the present application is the direction along the rotation axis, the circumferential direction is the circumferential direction around the rotation axis, and the radial direction is the straight line direction from the rotation axis to the edge of the transmission element 21, which is perpendicular to the axial direction.

[0049] The end of the transmission element 21 is provided with a plurality of teeth 211 distributed at intervals, and the plurality of teeth 211 are distributed around a circle along the circumferential direction. Each of the teeth 211 is formed by extending a distance from the edge of the transmission element 21 along the axial direction of the transmission element 21. The tooth 211 has two tooth surfaces 2111 facing opposite directions along the circumferential direction. The tooth surface 2111 is an arc surface. The two ends of the tooth 211 along the axial direction are narrower, and the middle part is wider, that is, the tooth 211 first extends from the end of the transmission element 21 from narrow to wide for a distance and then extends from wide to narrow for a distance.

[0050] A tooth groove 210 is formed between adjacent teeth 211 and is defined by two opposite tooth surfaces 2111. The deformation arm 11 of the serpentine spring 100 is embedded in the tooth groove 210 and located between two teeth 211. The tooth surfaces 2111 guide the deformation of the serpentine spring 100.

[0051] Further, the transmission element 21 includes a main transmission element 201 and a slave transmission element 202, the main transmission element 201 and the slave transmission element 202 are coaxially connected, and the serpentine spring 100 is embedded between the main transmission element 201 and the slave transmission element 202. The main transmission element 201 rotates, and is transmitted to the slave transmission element 202 through the serpentine spring 100, so as to drive the slave transmission element 202 to rotate, and transmit the torque from the main transmission element 201 to the slave transmission element 202.

[0052] The main transmission element 201 includes a plurality of active teeth 2011, wherein an active tooth groove 2010 is formed between adjacent active teeth 2011, and each active tooth 2011 has two active tooth surfaces 2012 facing in opposite directions. The slave transmission element 202 includes a plurality of driven teeth 2021, wherein a driven tooth groove 2020 is formed between adjacent driven teeth 2021, and each driven tooth 2021 has two driven tooth surfaces 2022 facing in opposite directions.

[0053] For the convenience of description, the first deformation unit 101 is embedded in the main transmission element 201, and the second deformation unit 102 is embedded in the slave transmission element 202. It can be understood that in other examples of the present application, the first deformation unit 101 can also be embedded in the slave transmission element 202, and the second deformation unit 102 can be embedded in the main transmission element 201.

[0054] The first deformation unit 101 is embedded in the active tooth groove 2010 , and the second deformation unit 102 is embedded in the driven tooth groove 2020 . The active tooth groove 2010 provides a deformation space for the first deformation arm 1011 of the first deformation unit 101 , and the driven tooth 2020 provides a deformation space for the second deformation arm 1021 of the second deformation unit 102 .

[0055] When the transmission assembly 200 is not working, the active teeth 2011 of the main transmission element 201 and the driven teeth 2021 of the driven transmission element 202 are aligned one by one, and the deformation arm 11 of the serpentine spring 100 is in a straight line. When the transmission assembly 200 is running, the main transmission element 201 rotates first, and the active teeth 2011 are displaced relative to the driven transmission element 201, so that the active teeth 2011 and the driven teeth 2021 are misaligned, and the active tooth surface 2012 of the main transmission element 201 generates a force on the first deformation unit 101 of the serpentine spring 100, causing the second deformation unit of the serpentine spring 100 to deform, and generates an axial force on the driven tooth surface 2022 of the driven transmission element 202, driving the driven transmission element 202 to move, and realizing torque transmission.

[0056] In one embodiment of the present application, the tooth surface 2111 is a curved surface, which is suitable for guiding the deformation arm 11 of the serpentine spring 100 to deform along the curved surface.

[0057] The tooth surface 2111 (including the active tooth surface 2012 and the driven tooth surface 2022) of the transmission assembly 200 is designed as a curved surface. The curved tooth surface can provide a larger relative curvature radius, which is conducive to increasing the contact area between the transmission element 21 and the serpentine spring 100, thereby improving the contact strength and stability, and also helps to reduce the stress concentration phenomenon in the contact area between the transmission element 21 and the serpentine spring 100, so that the load distribution of the transmission element 21 during the meshing process is more uniform, reducing the damage to the tooth surface caused by load concentration, which is conducive to improving the durability of the transmission element 21 and reducing the fatigue damage of the tooth surface 2111. The more uniform force distribution helps to reduce vibration and noise, and can also reduce friction and sliding during power transmission, thereby reducing energy loss, improving transmission efficiency, and improving the reliability of the transmission assembly 200. In addition, by accurately controlling the curved surface shape of the tooth surface 2111, the contact characteristics of the transmission element 21, including the contact area morphology and transmission error, can be better controlled, thereby improving the transmission accuracy. The tooth surface 2111 with curved surface design can also adapt to different load and speed conditions, providing better adaptability and flexibility.

[0058] When the transmission element 21 is not working, the surface of the deformable arm 11 contacts the tooth surface 2111 at the widest part of the tooth 211. The deformable arm 11 is substantially parallel to the rotation axis. There may be a gap between the surface of the deformable arm 11 and the tooth surface 2111 at the narrower part of the tooth 211. When the transmission element 21 is working, the transmission element 21 rotates around the rotation axis, the tooth 211 moves in the circumferential direction, the serpentine spring 100 follows the movement, and the deformable arm 11 is deformed to fit the tooth surface 2111, that is, deformed along the tooth surface 2111. As the load increases, the deformation of the serpentine spring 100 increases, the contact surface of the deformable arm 11 with the tooth 211 also increases, and the distance between the contact points with the tooth 211 becomes shorter and shorter. The stiffness of the serpentine spring 100 increases, and a nonlinear relationship is presented between the transmitted torque and the relative rotation angle of the two transmission elements 21. It is suitable for working conditions with large torque changes and forward and reverse rotation, and has a good buffering effect.

[0059] Specifically, in the initial state, the serpentine spring 100 keeps in contact with the tooth surface 2111 at the widest part of the tooth 211 of the transmission element 21, the serpentine spring 100 is in an unstressed state, and the deformable arm 11 is in a straight line. When the transmission component 200 starts to transmit torque, the part of the serpentine spring 100 located at the slave transmission element 202 is fixed, and the part located at the main transmission element 201 is subjected to force from the main transmission element 201. This force causes the serpentine spring 100 to deform along the active tooth surface 2012. As the torque increases, the serpentine spring 100 continues to deform along the active tooth surface 2012 and the driven tooth surface 2022, the straight part of the deformable arm 11 gradually bends, and the distance between the contact point with the tooth surface 2111 gradually decreases. Due to the deformation of the serpentine spring 100, its stiffness begins to increase. When the serpentine spring 100 reaches the maximum load, the deformation of the serpentine spring 100 also reaches the maximum. At this time, the distance between the contact point of the serpentine spring 100 and the tooth surface 2111 is the shortest, and the stiffness of the serpentine spring 100 reaches the maximum. When the torque decreases or disappears, the serpentine spring 100 begins to unload from the maximum load state, gradually returns to the original shape, and the distance between the contact point and the tooth surface 2111 gradually increases. After the unloading is completed, the serpentine spring 100 returns to the unstressed state, and the deformable arm 11 returns to the straight line shape.

[0060] Further, the curved cross-sectional shape of the tooth surface 2111 conforms to the characteristics of a variable curvature curve, or in other words, the cross-sectional shape of the tooth surface 2111 of the tooth 211 along the radial direction is a variable curvature curve, and the curvature at each position on the cross-sectional shape of the tooth surface 211 is changing. The tooth surface 2111 provides a contact interface with a variable curvature for the serpentine spring 100, causing the serpentine spring 100 to deform to present a shape of a variable curvature curve, thereby reducing stress impact.

[0061] Further, the tooth surface 2111 of the transmission element 21 is designed to conform to the variable curvature curve characteristics, and the curvature of each contact interface between the tooth surface 2111 and the serpentine spring 100 is changing, which enables the serpentine spring 100 to absorb and disperse stress more effectively when transmitting the power between the main transmission element 201 and the slave transmission element 202. The curvature change of the variable curvature curve can create a smoother force transition, so that the stress is more evenly distributed along the length of the serpentine spring 100, thereby reducing local stress peaks, especially under high load conditions, reducing the risk of fatigue and wear. In addition, by adjusting the curvature, the serpentine spring 100 can provide a more controlled deformation response to the driving force. This flexibility correspondingly reduces the transmission of shock and vibration to the slave transmission element 202, improves the anti-sudden load capacity of the serpentine spring 100, the transmission assembly 200 and the coupling 300 of the present application, and enhances durability.

[0062] Moreover, the variable curvature makes the engagement and separation between the serpentine spring 100 and the teeth of the transmission element 21 smoother, reduces the phenomenon of slippage or jumping between the teeth, and thus makes the power transmission more stable. The buffering effect of the serpentine spring 100 can also reduce the backlash (gap or looseness between gears), and the serpentine spring 100 fills the small gap at the contact point to ensure continuous torque transmission.

[0063] The variable curvature design can further improve the vibration reduction effect. The deformation of the serpentine spring 100 along the tooth surface 2111 is controlled, which improves the vibration absorption effect. The meshing between the active tooth 2011 and the driven tooth 2021 is relatively smooth, avoiding sudden impact, making the transmission assembly 200 quieter during operation.

[0064] Since the serpentine spring 100 can absorb stress and distribute it evenly, the direct metal contact between the teeth 211 of the transmission element 21 is reduced, thereby avoiding wear caused by long-term contact. Since the power transmission is relatively indirect, the material degradation of the teeth 211 of the transmission element 21 itself is reduced, thereby extending the service life of the transmission assembly 200.

[0065] That is, the active tooth surface 2012 and the driven tooth surface 2022 are both curved surfaces. Furthermore, the cross-sectional shape characteristics of the curved surface conform to the characteristics of a variable curvature curve. The force-bearing surface 110 of the serpentine spring 100 contacts the active tooth surface 2012 and the driven tooth surface 2022. When the serpentine spring 100 is deformed by force, the force-bearing surface 110 conforms to the active tooth surface 2012 and / or the driven tooth surface 2022 and deforms, and its cross-sectional shape also conforms to the characteristics of a variable curvature curve.

[0066] That is, the force-bearing surfaces 110 of the first deformable arm 1011 and the second deformable arm 1021 are in contact with the active tooth surface 2012 and the driven tooth surface 2022 respectively, so as to generate deformation that conforms to the cross-sectional shape and the variable curvature curve characteristics.

[0067] When the main transmission element 201 rotates clockwise, the deformable arm 11 is deformed by force, and a side surface of the first deformable arm 1011 of the deformable arm 11 is deformed along the active tooth surface 2012, presenting a variable curvature curve, causing the second deformable arm 1021 to deform, and a side surface of the second deformable arm 1021 is deformed along the driven tooth surface 2022, presenting a variable curvature curve, driving the slave transmission element 202 to rotate. If reverse movement is required, the main transmission element 201 rotates counterclockwise, and the torque is transmitted through the serpentine spring 100, driving the slave transmission element 202 to rotate.

[0068] Further, the cross-sectional shape of the tooth surface 211 of the tooth 211 along the radial direction is a logarithmic curve, so that the tooth surface 211 provides a gradually changing curvature, so that the deformation of the serpentine spring 100 is smoother. More preferably, the variable curvature of the cross-sectional shape of the serpentine spring is designed as a logarithmic curve to provide a smoother stress transition. The logarithmic curve provides a gradually changing slope, so that the force can be smoothly and gradually distributed along the length of the serpentine spring 100. The smooth transition of force minimizes sudden stress points, distributes stress more widely, reduces peak stress, and distributes the load more evenly on the serpentine spring 100, thereby reducing local stress concentration, avoiding excessive stress on certain areas of the serpentine spring 100, reducing the risk of material fatigue or failure of the serpentine spring 100, extending the service life of the serpentine spring 100, and showing stronger tolerance under high loads and repeated stress cycles. It is suitable for industrial or heavy-load applications requiring high durability.

[0069] In addition, the deformable arm 11 presenting a logarithmic shape provides an efficient path for force transmission from the main transmission element 201 to the slave transmission element 202. Since the logarithmic curve gradually distributes the applied force, the energy loss caused by unnecessary vibration or resistance is reduced, thereby making the power transmission more efficient. The progressive curvature of the logarithmic curve reduces the possibility of the serpentine spring 100 jumping or slipping between the teeth of the transmission element 21, thereby reducing the tooth gap and ensuring that the torque is continuously and accurately transmitted between the transmission elements 21, making the transmission assembly 200 more accurate and efficient. In addition, the logarithmic curvature design can provide controlled deformation when the force increases, so that the serpentine spring 100 absorbs energy more gently, thereby improving its ability to buffer impact and shock absorption, and will not suddenly become stiff or produce obvious deformation. In addition, the logarithmic curve design enables the serpentine spring 100 to naturally absorb shock because it distributes force in a nonlinear manner. This shock absorption effect reduces vibration and reduces noise caused by impact or sudden force, making the transmission assembly 200 quieter and smoother in operation. The logarithmic curve ensures that the engagement and separation of the serpentine spring 100 and the teeth 211 of the transmission element 21 occur gradually, reducing the impact force and avoiding the phenomenon that may cause bouncing or clicking sounds.

[0070] In more specific design, the flexible nature of the logarithmic function allows the curvature to be customized according to specific load conditions by adjusting the parameters of the logarithmic equation. This adaptability allows the serpentine spring 100 to optimize performance under various working conditions, whether light or heavy load, low speed or high speed, and also enables the serpentine spring 100 to dynamically respond to different loads, maintain stability and efficiency, and avoid becoming too stiff under high loads.

[0071] The present application also provides a coupling 300, which includes the above-mentioned transmission assembly 200 and serpentine spring 100, wherein the serpentine spring 100 is embedded in the transmission assembly 200 for transmission, wherein the transmission assembly 200 includes a main transmission element 201 and a slave transmission element 202 connected to each other, and the serpentine spring 100 is embedded in the main transmission element 201 and the slave transmission element 202 for transmission.

[0072] refer to Figure 8 As shown in , it provides a specific design method of the variable curvature curve of the present invention, wherein L is the distance from the end of the transmission shaft tooth to the end of the driven shaft tooth, x is the x coordinate of the calculation point, y is the y coordinate of the calculation point, δ is the circumferential offset of the transmission shaft and the driven shaft under the maximum torque, F is the axial friction force between the snake spring and the tooth under the maximum torque, M is the bending moment of each point when the snake spring is deformed, and MB is the bending moment of point B.

[0073] According to the following formula:

[0074] I=bh3 / 12; A = bh

[0075] I is the moment of inertia of the snake spring, b is the width of the snake spring, h is the thickness of the snake spring, and A is the cross-sectional area of ​​the snake spring. From the figure, the deflection equation of the snake spring is:

[0076]

[0077] E is the elastic modulus of the snake spring, P is the force of the tooth on the snake spring under maximum torque, and the general solution of this equation is:

[0078] y=c1cosh(tx)+c2sinh(tx)+Ax+B (2)

[0079] Among them, C1, C2, t, A, B are unknown coefficients. Substituting formula (2) into formula (1) yields:

[0080] EiC 2 cosh(tx)+EIc2t 2 sinh(tx)=Fc1cosh(tx)+Fc2sinh(tx)+FAx+FB+Px-M B -PL

[0081] Comparing the coefficients on both sides of the equation, we can get:

[0082]

[0083] According to the boundary condition, the rotation angle θ of point B is 0, that is:

[0084]

[0085] The remaining two unknown coefficients c1 and c2 can be obtained:

[0086]

[0087] The only unknown moment MB is left. Using the boundary condition y x＝L =0, that is:

[0088]

[0089] Substituting each coefficient into the equation, we can get the snake spring curve equation:

[0090]

[0091] Since the larger the contact surface between the tooth and the snake spring is at maximum torque, the smaller the stress is, and the more similar the contact surface curves are, the more uniform the stress distribution is. Therefore, the curve equation of the tooth is the same as the curve equation of the snake spring after deformation under maximum torque. The range of x in the equation can be selected according to the length of the tooth.

[0092] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached claims and their equivalents.

Claims

1. A serpentine spring, characterized in that: include: A plurality of first bending arms, a plurality of deformable arms and a plurality of second bending arms, each of the first bending arms, each of the deformable arms and each of the second bending arms are connected in sequence, wherein when the serpentine spring is in a stressed state, the cross-sectional shape of the surface of the deformable arm presents a variable curvature curve.

2. The serpentine spring according to claim 1, characterized in that: The serpentine spring includes multiple first deformation units and multiple second deformation units, each of the first deformation units and each of the second deformation units are connected in sequence and arranged in a centrally symmetrical manner, one of the first deformation unit and the second deformation unit is suitable for being mounted on the main transmission element of the coupling, and the other is suitable for being mounted on the slave transmission element of the coupling.

3. The serpentine spring according to claim 1, characterized in that: The first deformation unit includes the first bending arm and two first deformation arms, and the first deformation arm, the first bending arm and another first deformation arm are connected in sequence to form a U shape. The second deformation unit includes the second bending arm and two second deformation arms, and the second deformation arm, the second bending arm and another second deformation arm are connected in sequence to form a U shape.

4. The serpentine spring according to claim 3, characterized in that: The first deformable arm and the second deformable arm are connected to form the deformable arm, wherein when the serpentine spring is in a stressed state, the cross-sectional shapes of the first deformable arm and the second deformable arm present a logarithmic curve shape.

5. The serpentine spring according to claim 1, characterized in that: The variable curvature curve is obtained by the following design method: Where L is the distance from the end of the transmission shaft tooth to the end of the driven shaft tooth, x is the x-coordinate of the calculation point, y is the y-coordinate of the calculation point, δ is the circumferential offset of the transmission shaft and the driven shaft under the maximum torque, F is the axial friction force between the snake spring and the tooth under the maximum torque, M is the bending moment at each point when the snake spring is deformed, and MB is the bending moment at point B. According to the following formula: I=bh 3 / 12;A=bh I is the moment of inertia of the snake spring, b is the width of the snake spring, h is the thickness of the snake spring, and A is the cross-sectional area of ​​the snake spring. From the figure, the deflection equation of the snake spring is: E is the elastic modulus of the snake spring, P is the force of the tooth on the snake spring under maximum torque, and the general solution of this equation is: y=c1cosh(tx)+c2sinh(tx)+Ax+B (2) Among them, C1, C2, t, A, B are unknown coefficients. Substituting formula (2) into formula (1) yields: EIc1t 2 cosh(tx)+EIc2t 2 sinh(tx)=Fc1cosh(tx)+Fc2sinh(tx)+FAx+FB+Px-M B -PL Comparing the coefficients on both sides of the equation, we can get: A=-P / F According to the boundary condition, the rotation angle θ of point B is 0, that is: The remaining two unknown coefficients c1 and c2 can be obtained: The only unknown moment MB is left. Using the boundary condition y x＝L =0, that is: Substituting each coefficient into the equation, we can get the snake spring curve equation:

6. A transmission assembly, suitable for a coupling, characterized in that: include: At least two transmission elements, the transmission elements are coaxially connected, wherein the transmission element comprises a plurality of teeth distributed at intervals, and the cross-sectional shape of the tooth surface conforms to the variable curvature curve characteristic; and A serpentine spring is sleeved on the transmission element to transmit between the transmission elements, wherein the serpentine spring includes a deformable arm, a portion of which is embedded between the teeth and deformed along the tooth surface so that the cross-sectional shape of the deformable arm presents a variable curvature curve characteristic.

7. The transmission assembly according to claim 6, characterized in that: The transmission element comprises a main transmission element and a slave transmission element, the main transmission element and the slave transmission element are coaxially connected, and the serpentine spring is sleeved between the main transmission element and the slave transmission element to transmit torque.

8. The transmission assembly according to claim 7, characterized in that: The main transmission element includes a plurality of active teeth distributed around the circumference, an active tooth groove is formed between the active teeth, and each active tooth has two active tooth surfaces facing opposite directions along the circumference, wherein the cross-sectional shape of the active tooth surface conforms to the logarithmic curve characteristic.

9. The transmission assembly according to claim 8, characterized in that: The driven transmission element includes a plurality of driven teeth distributed around a circle along the circumferential direction, a driven tooth groove is formed between each of the driven teeth, and each of the driven teeth has two driven tooth surfaces facing opposite directions along the circumferential direction, wherein the cross-sectional shape of the driven tooth surface conforms to the logarithmic curve characteristic.

10. A coupling, characterized in that: include: Comprising a transmission assembly as described in any one of claims 6 to 9.

Images