Damping coefficient evaluation method of damping and transmission free switching device

Abstract

The invention belongs to the technical field of mechanical transmission, and provides a damping coefficient evaluation method of a damping and transmission free switching device. Through electromagnetic interaction, a non-contact design is adopted in a transmission mode, and electromagnetic force between the permanent magnet and the high-conductivity damping disc is utilized, so that efficient transmission is realized, and mechanical friction and energy loss are reduced; in the damping mode, the pin shaft is inserted to fix the damping disc, an induced magnetic field is generated to provide a damping function, load change is adapted, and stable control is achieved. And the system has the characteristics of high adaptability, low maintenance and low energy consumption. In addition, according to the damping coefficient evaluation method, calculation is carried out by considering power consumption and angular velocity, the traditional finite element analysis process is simplified, the system efficiency and precision are improved, and complex modeling and high calculation load are avoided. The method has good practical application performance in the aspect of practical engineering application, operation is easy, and the calculated amount is small.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical transmission, and in particular relates to a damping coefficient evaluation method of a damping and transmission free switching device. Background Art

[0002] In the automotive and modern industrial fields, transmission and damping devices are widely used. The transmission device is responsible for efficiently transmitting the energy generated by the power device to the actuator and the load to ensure the normal operation of the mechanical equipment, while the damping device plays an important role in situations where deceleration or smooth stopping is required, such as controlling vibration and avoiding impact. Traditional transmission devices mainly realize power transmission through mechanical connections such as couplings and gears. However, due to friction, vibration and other reasons, the wear between mechanical parts is large, and it is difficult to adapt to the needs under different working conditions. The damping system usually relies on hydraulic, pneumatic or friction braking. Although these systems can effectively provide damping, their control methods are limited, and the damping effect cannot be flexibly adjusted according to real-time needs. In the prior art, the transmission and damping functions are usually implemented separately. When faced with complex and changeable working conditions, they often cannot be flexibly converted to cope with different transmission and damping requirements, resulting in the efficiency and reliability of the system being difficult to guarantee. Therefore, the present invention provides a device that realizes free switching between transmission and damping through a damping automatic pin shaft, which can realize the conversion of efficient transmission and damping function through simple mechanical operation under different working conditions, and at the same time proposes a simple damping coefficient evaluation method, which provides a more flexible solution for mechanical transmission systems. In addition, in the study of damping coefficient evaluation, the finite element analysis method is usually used. However, in the actual modeling process, factors such as material properties, boundary conditions, and external loads need to be considered, which makes the calculation time long, the hardware performance requirements are high, the calculation process is complicated, and the efficiency is extremely low. This seriously restricts the structural design and performance optimization of the damping device. Therefore, the invention of a damping coefficient evaluation method that can take into account both calculation accuracy and efficiency has irreplaceable value and significance for improving the performance of the damping device and realizing the diversification of the damping device used in the field of industrial machinery.

[0003] Regarding the torque transmission device, Lin Sanying proposed in the patent "A transmission shaft damping device" (CN202321427030.1) that the external force received by the power output end is connected to the linkage shaft by an attached damping device on the linkage shaft, so as to greatly reduce the force transmitted to the linkage shaft by the external force received by the power output end. Although the buffering function can be realized, effective braking cannot be achieved when facing a large impact load. Regarding the damping coefficient evaluation calculation method, Yang Deyou, in the article "Generator Inertia and Damping Coefficient Evaluation Method Based on Dynamic Mode Decomposition", constructed a linear equation about electromechanical parameters (inertia and damping coefficient) and system characteristics (eigenvalues ​​and eigenvectors) based on dynamic mode decomposition, and then realized the evaluation of the damping coefficient by solving the linear equation. However, this method involves too many parameters and they are mutually coupled, which makes the analytical calculation of the linear equation difficult and the decoupling process complicated. Therefore, proposing a damping and transmission free switching device and a damping coefficient evaluation method is of great significance for the design and characteristic research of high-flexibility basic parts for switching transmission damping functions in the automotive and modern industrial fields. Summary of the invention

[0004] In order to make up for the defects of the prior art, the present invention invents a free switching device for damping and transmission. Its purpose is to achieve free switching through a damping brake pin shaft. When the pin shaft is pulled out, the electromagnetic interaction between the magnetic force of the permanent magnet in the transmission switching disk and the high-conductivity damping disk is used to achieve contactless transmission, effectively reducing mechanical friction and energy loss; when the pin shaft is inserted, the damping disk is fixed, and an induced magnetic field is generated by cutting the magnetic flux lines to provide a damping effect. The device has the advantages of flexible switching of transmission and damping, mechanical contact-free transmission, and low energy loss. It is particularly suitable for industrial automation, automobile speed change, wind power generation and other occasions with large load changes. In addition, the innovative design of contactless transmission and damping of induced magnetic field achieved by magnetic force improves the adaptability and operating efficiency of the system, simplifies the structure and reduces maintenance costs, and has broad application prospects.

[0005] The technical solution of the present invention:

[0006] A damping coefficient evaluation method for a damping and transmission free switching device, the steps are as follows:

[0007] The first step is to build a damping and transmission free switching device;

[0008] First, the permanent magnet is embedded in the transmission switching disc slot, and one end of the transmission switching disc is connected to the power device through an extended shaft; secondly, the high-conductivity damping disc and the damping bearing disc are fixed together by bolts, and one end of the damping bearing disc is connected to the roller bearing through an extended shaft; then, the high-conductivity damping disc is inserted into the transmission switching disc, and the two ends are aligned; a through hole is opened on the roller bearing to cooperate with the damping brake pin shaft, and the switching of the transmission and damping functions is realized in turn. When the device is operating normally, the driving device drives the transmission switching disc to rotate. When the pin shaft is pulled out, the device realizes contactless transmission through the electromagnetic interaction between the permanent magnet and the high-conductivity damping disc in the transmission switching disc, effectively reducing mechanical friction and energy loss; when the pin shaft is inserted, the high-conductivity damping disc is fixed together with the damping bearing disc and the roller bearing. At this time, the transmission switching disc rotates, and the high-conductivity damping disc cuts the magnetic flux lines to generate an induced magnetic field, providing a damping effect. The present invention has a compact structure, can provide mechanical contact-free transmission and highly adaptable damping effect, and has high practicality and engineering application promotion value.

[0009] The damping and transmission free switching device comprises a damping brake pin shaft 1, a roller bearing 2, a damping bearing plate 3, a connecting bolt 4, a high conductivity damping plate 5, a permanent magnet 6, a transmission switching plate 7, a base 8 and a gantry 9;

[0010] The permanent magnet 6 is embedded in the groove of the transmission switching disk 7, one end of the transmission switching disk 7 is connected to the power device through an extended shaft and installed on the base 8; the high-conductivity damping disk 5 and the damping bearing disk 3 are fixed together by connecting bolts 4, one end of the damping bearing disk 3 is connected to the roller bearing 2 through an extended shaft, and a damping brake pin shaft 1 is installed between the two; the roller bearing 2 is fixed on the gantry 9; the high-conductivity damping disk 5 is inserted into the transmission switching disk 7, and the damping disk 5 and the two sides of the transmission switching disk 7 are aligned to complete the installation;

[0011] Step 2: Determine the key parameters of the device;

[0012] The angular velocity of the power device when in operation is ω, the transmission switching disk 7 is connected to the power device, and the angular velocity of the damping and transmission free switching device when working is provided by the power device and gradually decreases to 0. Therefore, the working angular velocity of the damping and transmission free switching device takes the root mean square value of the angular velocity of the power device, that is, The magnetic field strength B between the high conductivity damping disk 5 and the permanent magnet 6 is determined by the material of the permanent magnet and is affected by the magnetic resistance of the device structure; the radius of the high conductivity damping disk 5 is r, and the thickness is h; r3 and r2 are the outer diameter and inner diameter of the transmission switching disk 7 respectively; L is the air gap length between the high conductivity damping disk 5 and the permanent magnet 6; a, b, c are the length, width, and height of the permanent magnet 6 respectively;

[0013] Step 2: Calculate the operating frequency and the volume of the high conductivity damping disk 5

[0014] The working frequency f of the damping and transmission free switching device is determined by its working angular velocity ω m To determine, that is:

[0015]

[0016] The high conductivity damping disk 5 is in the shape of a cylinder with a radius of r and a thickness of h, so its volume V is:

[0017] V=πr 2 h (2)

[0018] Step 3: Calculate the magnetic field strength;

[0019] The magnetic field strength B is determined by the material of the permanent magnet 6; the magnetic permeability of the back iron material is much greater than that of air, so in the actual calculation, it is necessary to consider the influence of the magnetic resistance of the back iron material on the magnetic flux of the magnetic circuit, so as to make the calculation result closer to the actual value;

[0020] The magnetic resistance calculation of the damping and transmission free switching device follows the regular magnet calculation formula, namely:

[0021]

[0022] In the formula, l m is the length in the magnetization direction, μ is the magnetic permeability, A m is the cross-sectional area of ​​the surface through which the magnetic lines of force pass;

[0023] Therefore, the back ferromagnetic resistance expression of the transmission switching disk 7 is:

[0024]

[0025] In the formula, μ1 is the relative magnetic permeability of the back iron material; μ0 is the vacuum magnetic permeability; n is the angle between the center lines of a pair of adjacent magnetic poles, that is, n = 360 / k; k is the number of magnetic pole pairs;

[0026] The internal resistance expression of permanent magnet 6 is:

[0027]

[0028] In the formula, μ pm is the relative magnetic permeability of the permanent magnet;

[0029] The expression of air gap reluctance is:

[0030]

[0031] In the formula, μ a is the relative magnetic permeability of air;

[0032] In addition, the permanent magnet 6 is regarded as a constant and reliable magnetic source, providing a continuous and effective magnetic field, and its magnetomotive force F0 is:

[0033] F0=H pm c (7)

[0034] In the formula, H pm represents the coercive force of the permanent magnet 6;

[0035] The magnetic flux Φ1 of the magnetic circuit after the magnetic resistance correction is:

[0036]

[0037] The corrected expression of magnetic field intensity B is:

[0038] B=B0·λ (9)

[0039] In the formula, λ is the correction coefficient, and its expression is:

[0040]

[0041] Where, B0 is the initial magnetic field strength determined by the material properties of the permanent magnet 6; Φ a is the magnetic flux of the original magnetic circuit, which is determined by the material of the permanent magnet 6. The values ​​of the above two parameters are fixed values;

[0042] Step 4: Calculate the eddy current loss power of the smallest element;

[0043] The power loss of the damping and transmission free switching device is mainly due to the eddy current effect caused by the high conductivity damping disk 5 cutting the magnetic flux lines in the magnetic field. The power of this eddy current loss is mainly dissipated in the form of heat. The power of eddy current loss dP m Calculated by the following formula:

[0044] dP m = k·B 2 ·f 2 ·dV (11)

[0045] Where: k is related to the material conductivity and geometric shape, and is taken as 12; B is the magnetic field intensity; f is the operating frequency of the damping and transmission free switching device; dV is the volume element;

[0046] Step 5: Calculate the total eddy current loss power of the high conductivity damping disk 5;

[0047] In order to obtain the total eddy current loss, it is necessary to integrate the high conductivity damping disk 5, usually in the form of:

[0048] P m =∫ V k·B 2 ·f 2 ·dV=k·B 2 ·f 2 ∫V dV (12)

[0049] Where: k is related to the material conductivity and geometric shape, and is taken as 12; B is the magnetic field intensity; f is the operating frequency of the damping and transmission free switching device; V is the volume of the high conductivity damping disk 5;

[0050] Step 6: Solve the damping coefficient;

[0051] The damping coefficient describes the magnitude of the damping force in the damping and transmission free switching device. The calculation formula is as follows:

[0052]

[0053] Where: P m is the eddy current loss power; ω m is the working angular velocity of the damping and transmission free switching device;

[0054] At this point, a damping and transmission free switching device and a damping coefficient calculation are completed.

[0055] The beneficial effect of the present invention is that a damping and transmission free switching device is proposed, which is based on a unique electromagnetic interaction principle, combines the dual functions of transmission and damping, and realizes flexible switching of transmission and damping modes through simple mechanical operation. In the transmission mode, there is no direct contact between mechanical parts, which greatly reduces friction and wear, prolongs the service life of the equipment, and significantly reduces energy loss. This contactless transmission mode avoids the noise and vibration caused by friction in conventional gear transmission or chain transmission, so the system is quieter and smoother during operation. In addition, the damping function of the device can play a role when the load fluctuates or needs to be decelerated smoothly. The damping effect formed by the reverse induced magnetic field generated by electromagnetic induction can quickly respond to load changes, avoid the hysteresis problem of traditional damping devices when switching, and improve the sensitivity and response speed of the system. This damping mode is based on electromagnetic induction, avoids the dependence of hydraulic or friction damping devices on the external environment (such as temperature, humidity, etc.), and enables the device to operate stably under harsh working conditions. The present invention proposes a damping coefficient evaluation calculation method taking into account eddy current loss and angular velocity. Compared with the finite element analysis method, the calculation process of this method is significantly simplified. When the finite element method is used to evaluate the damping coefficient, it is usually necessary to finely model the system and perform a large amount of meshing on the model, which involves solving complex partial differential equations. Although finite element analysis can provide highly accurate local analysis results, its calculation complexity is high, the calculation time is long, and the requirements for hardware equipment are high, making it difficult to adapt to occasions that require real-time adjustment or rapid response. In contrast, the calculation method based on power and angular velocity does not require complex modeling and meshing. It only needs to calculate the power consumption and angular velocity of the system to quickly obtain the damping coefficient, which can accurately reflect the damping effect of the system under different loads and working conditions. It is particularly suitable for real-time monitoring and adjustment in industrial production. In summary, the damping and transmission free switching device and damping coefficient evaluation method proposed in the present invention provide a simple and accurate calculation method for the design optimization and performance improvement of similar devices, which is suitable for a wide range of engineering applications and effectively improves the flexibility and stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a schematic diagram of a damping and transmission free switching device;

[0057] Figure 2 It is a flow chart of a damping and transmission free switching device and a damping coefficient evaluation method;

[0058] Figure 1 Middle: 1-damping brake pin, 2-roller bearing, 3-damping bearing plate, 4-connecting bolt, 5-high conductivity damping plate, 6-permanent magnet, 7-transmission switching plate, 8-base, 9-gantry. DETAILED DESCRIPTION

[0059] The embodiments of the present invention are further described below in conjunction with the accompanying drawings and technical solutions.

[0060] This embodiment selects a damping and transmission free switching device with 6 pairs of magnetic poles and evaluates and calculates its damping coefficient.

[0061] Among them, the length of the damping brake pin shaft 1 is 20mm, the diameter is 1.5mm, the roller bearing 2 uses the GB283-94 roller bearing with a shaft diameter of 15mm, the damping bearing plate 3 has a diameter of 48mm and a thickness of 8mm, the connecting bolt 4 uses 4 M5×10 hexagon socket bolts, the high conductivity damping plate 5 has a diameter of 48mm and a thickness of 24mm, the permanent magnet 6 has a thickness of 5mm and a height of 5mm, and the transmission switching plate 7 has a diameter of 70mm and a thickness of 30mm

[0062] The installation steps of the damping and transmission free switching device are as follows:

[0063] The permanent magnet 6 is embedded in the groove of the transmission switching disk 7, and one end of the transmission switching disk 7 is connected to the power device through an extended shaft and installed on the base 8; secondly, the high-conductivity damping disk 5 and the damping bearing disk 3 are fixed together by 4 M5×10 hexagon socket bolts, and one end of the damping bearing disk 3 is connected to the roller bearing 2 through an extended shaft; a damping brake pin shaft 1 is installed between the two; the roller bearing 2 is fixed on the gantry 9; then, the high-conductivity damping disk 5 is inserted into the transmission switching disk 7, and the two sides of the damping disk 5 and the transmission switching disk 7 are aligned to complete the installation.

[0064] At this point, a damping and transmission free switching device is installed.

[0065] A damping and transmission free switching device and a damping coefficient evaluation calculation method as shown in Figure 2 The specific steps for evaluating and calculating the damping coefficient of the damping and transmission free switching device are as follows:

[0066] Step 1: Determine the key parameters of the device

[0067] The angular velocity of the power unit during operation is ω = 150 rad / s, and the working angular velocity of the damping device is ω m =75rad / s; the radius of the high conductivity damping disk is r=24mm, and the thickness is h=24mm; the outer diameter of the conversion disk is r3=35mm and the inner diameter is r2=29mm; the air gap length between the high conductivity damping disk and the permanent magnet is L=5mm; the length, width and height of the permanent magnet are a=20mm, b=10mm, and c=5mm respectively;

[0068] Step 2: Calculate the operating frequency and volume of the damping disk. From formula (1), we can get the operating frequency of the damping device f≈11.9Hz

[0069] From formula (2), we can get the volume of the damping disk V = 0.0000434m 3

[0070] Step 3: Calculate the magnetic field strength. From formula (4), we can get the back iron magnetic resistance of the transmission switching disk R1 = 0.45Ω; from formula (5), we can get the internal resistance of the permanent magnet Rpm = 1.25Ω; from formula (6), we can get the air gap magnetic resistance Ra = 0.75Ω; from formula (7), we can get the magnetomotive force of the permanent magnet F0 = 448AT; from formula (8), we can get the magnetic flux of the magnetic circuit after the magnetic resistance correction Φ1 = 246Wb; the initial magnetic field strength and the original magnetic flux are determined by the permanent magnet material, and their values ​​are: B0 = = 1.67T, Φ a =294Wb; Based on formulas (9) and (10), the corrected magnetic field strength B = 1.579T

[0071] Step 4: Calculate the eddy current loss power of the smallest element

[0072] Substituting the result of the second step into formula (3), the differential form of eddy current loss power can be obtained:

[0073] Step 5: Calculate the total eddy current loss power of the damping disk

[0074] Substituting the result of the third step into formula (4) and integrating it over the volume of the damping disk, we can get p m =1.65

[0075] Step 6: Solve for the damping coefficient

[0076] Substituting the eddy current loss power and the working angular velocity of the device calculated above into formula (5), the damping coefficient D = 0.022

[0077] At this point, the calculation of the damping and transmission free switching device and the damping coefficient has been completed.

[0078] This new type of structural damping and transmission free switching device realizes flexible switching of transmission and damping functions through a unique damping brake pin shaft structure. In the transmission mode, magnetic coupling is used for contactless torque transmission, reducing mechanical wear and energy loss; in the damping mode, an induced magnetic field is generated by cutting magnetic flux lines, providing an efficient damping effect, thereby achieving effective control of the system movement.

[0079] This method proposes a damping coefficient calculation method based on power and angular velocity, which simplifies the traditional finite element analysis method. It is fast and easy to implement, suitable for real-time monitoring and dynamic adjustment, and does not rely on complex physical models and computing resources. The device can evaluate the damping effect under different actual working conditions and has stronger adaptability. At the same time, it overcomes the high computational complexity and long solution process of the finite element method, greatly shortens the evaluation time, and enables the system to be optimized in real time during operation.

Claims

1. A damping coefficient evaluation method for a damping and transmission free switching device, characterized in that: Here are the steps: The first step is to build a damping and transmission free switching device; The damping and transmission free switching device comprises a damping brake pin shaft (1), a roller bearing (2), a damping bearing plate (3), a connecting bolt (4), a high conductivity damping plate (5), a permanent magnet (6), a transmission switching plate (7), a base (8) and a gantry (9); The permanent magnet (6) is embedded in the groove of the transmission switching disk (7); one end of the transmission switching disk (7) is connected to the power device through an extended shaft and installed on the base (8); the high-conductivity damping disk (5) and the damping bearing disk (3) are fixed together through a connecting bolt (4); one end of the damping bearing disk (3) is connected to the roller bearing (2) through an extended shaft, and a damping brake pin shaft (1) is installed between the two; the roller bearing (2) is fixed on the gantry (9); the high-conductivity damping disk (5) is inserted into the transmission switching disk (7), and the two sides of the damping disk (5) and the transmission switching disk (7) are aligned, and the installation is completed; Step 2: Determine the key parameters of the device; The angular velocity of the power device when in operation is ω, the transmission switching disk (7) is connected to the power device, and the angular velocity of the damping and transmission free switching device when in operation is provided by the power device and gradually decreases to 0, so the working angular velocity of the damping and transmission free switching device is the root mean square value of the angular velocity of the power device, that is, The magnetic field intensity B between the high conductivity damping disk (5) and the permanent magnet (6) is determined by the material of the permanent magnet and is affected by the magnetic resistance of the device structure; the radius of the high conductivity damping disk (5) is r and the thickness is h; r3 and r2 are respectively the outer diameter and inner diameter of the transmission switching disk (7); L is the air gap length between the high conductivity damping disk (5) and the permanent magnet (6); a, b, and c are respectively the length, width, and height of the permanent magnet (6); Step 2: Calculate the operating frequency and the volume of the high conductivity damping disk (5) The working frequency f of the damping and transmission free switching device is determined by its working angular velocity ω m To determine, that is: The high conductivity damping disk (5) is in the shape of a cylinder with a radius of r and a thickness of h, so its volume V is: V=πr 2 h (2) Step 3: Calculate the magnetic field strength; The magnetic field strength B is determined by the material of the permanent magnet (6); the magnetic permeability of the back iron material is much greater than that of air, so in the actual calculation, it is necessary to consider the influence of the magnetic resistance of the back iron material on the magnetic flux of the magnetic circuit, so as to make the calculation result closer to the actual value; The magnetic resistance calculation of the damping and transmission free switching device follows the regular magnet calculation formula, namely: In the formula, l m is the length in the magnetization direction, μ is the magnetic permeability, A m is the cross-sectional area of ​​the surface through which the magnetic lines of force pass; Therefore, the expression of the back iron magnetic resistance of the transmission switching disk (7) is: Wherein, μ1 is the relative magnetic permeability of the back iron material; μ0 is the vacuum magnetic permeability; n is the angle between the center lines of a pair of adjacent magnetic poles, that is, n = 360 / k; k is the number of magnetic pole pairs; The internal resistance expression of permanent magnet (6) is: In the formula, μ pm is the relative magnetic permeability of the permanent magnet; The expression of air gap reluctance is: In the formula, μ a is the relative magnetic permeability of air; In addition, the permanent magnet (6) is regarded as a constant and reliable magnetic source, providing a continuous and effective magnetic field, and its magnetomotive force F0 is: F0=H pm c (7) In the formula, H pm represents the coercive force of the permanent magnet (6); The magnetic flux Φ1 of the magnetic circuit after the magnetic resistance correction is: The corrected expression of magnetic field intensity B is: B=B0·λ (9) In the formula, λ is the correction coefficient, and its expression is: Wherein, B0 is the initial magnetic field strength determined by the material properties of the permanent magnet (6); Φ a is the magnetic flux of the original magnetic circuit, which is determined by the material of the permanent magnet (6). The values ​​of the above two parameters are fixed values; Step 4: Calculate the eddy current loss power of the smallest element; The power loss of the damping and transmission free switching device is mainly due to the high conductivity damping disk (5) cutting the magnetic flux lines in the magnetic field, resulting in the eddy current effect and causing energy loss; the power of this eddy current loss is mainly dissipated in the form of heat; the power of eddy current loss dP m Calculated by the following formula: dP m =k·B 2 ·f 2 ·dV (11) Where: k is related to the material conductivity and geometric shape, and is taken as 12; B is the magnetic field intensity; f is the operating frequency of the damping and transmission free switching device; dV is the volume element; Step 5, calculating the total eddy current loss power of the high conductivity damping disk (5); In order to obtain the total eddy current loss, it is necessary to integrate the high conductivity damping disk (5), usually in the form of: P m =∫ V k·B 2 ·f 2 ·dV=k·B 2 ·f 2 ∫ V dV (12) Where: k is related to the material conductivity and geometric shape, and is taken as 12; B is the magnetic field intensity; f is the operating frequency of the damping and transmission free switching device; V is the volume of the high conductivity damping disk (5); Step 6: Solve the damping coefficient; The damping coefficient describes the magnitude of the damping force in the damping and transmission free switching device. The calculation formula is as follows: Where: P m is the eddy current loss power; ω m is the working angular velocity of the damping and transmission free switching device; At this point, a damping and transmission free switching device and a damping coefficient calculation are completed.

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