A testing method for angular stiffness and radial stiffness of a diaphragm coupling

Abstract

The present invention provides a test method for the angular stiffness and radial stiffness of a diaphragm coupling. First, both ends of the diaphragm coupling are respectively connected to a first adapter and a second adapter. The first adapter is firmly installed on the experimental bench, and the second adapter is in a cantilever state. Determine the pressure application position on the second adapter and adjust the position of the laser displacement sensor. Gradually apply pressure to the second adapter through a pressure loading rod, record the values of the pressure sensor and the laser displacement sensor, and obtain the first set of measurement data. Change the pressure application position on the second adapter and adjust the position of the laser displacement sensor. Apply pressure to the second adapter step by step again, record the values of the pressure sensor and the laser displacement sensor, and obtain the second set of measurement data. Based on the first set of measurement data and the second set of measurement data, solve the stiffness value according to the stiffness calculation model of the angular and radial directions of the diaphragm coupling.

Description

Technical Field

[0001] The present invention relates to the field of coupling mechanics, and particularly to a method for testing the angular stiffness and radial stiffness of a diaphragm coupling. Background Art

[0002] Diaphragm couplings are widely used in shafting transmissions such as steam turbines, compressors, marine and aviation equipment. They are flexible elements that compensate for various offsets between drive shafts through the deformation of metal diaphragm groups, and have the advantages of compact structure, reliable connection, no need for lubrication, strong ability to withstand bias pressure, and good environmental adaptability. Diaphragm couplings play an important role in mechanical power transmission, and their mechanical properties are directly related to the safety and stability of shafting transmission; in addition, the stiffness characteristics of diaphragm couplings reflect their ability to compensate for misalignment between shafts, which is a basic index that must be considered when evaluating coupling characteristics and selecting coupling models.

[0003] Studying the mechanical properties of diaphragm couplings through stiffness test experiments is of great significance for shafting transmission, coupling selection, etc. At present, the test experiments for the angular stiffness and radial stiffness of diaphragm couplings usually design two independent fixture structures to separately test the angular stiffness and radial stiffness of the diaphragm coupling. The radial stiffness is directly solved from the radial displacement value and radial force through the corresponding stiffness calculation method, and the angular stiffness is solved from the angular displacement value and angular torque. The existing test methods for the angular stiffness and radial stiffness of diaphragm couplings require designing two fixture structures and conducting stiffness tests on different test benches, consuming more economic and time costs; moreover, directly solving the angular stiffness and radial stiffness of the diaphragm coupling from the test data of displacement value / rotation angle value and force / torque results in the coupled results of the two stiffnesses, and there will be a large error between the actual angular stiffness and radial stiffness of the diaphragm coupling and the test results.

[0004] Therefore, a new technical solution is needed to solve the above problems. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a method for testing the angular stiffness and radial stiffness of a diaphragm coupling. Only one fixture structure needs to be designed and the test is conducted on the same test bench to obtain the measurement data for calculating the angular stiffness and radial stiffness of the coupling. The test method for the angular stiffness and radial stiffness of the diaphragm coupling is reasonable, the stiffness calculation model is reliable, it can achieve the decoupling of the angular stiffness and radial stiffness of the coupling, improve the accuracy of the coupling stiffness test results, and is of great significance for evaluating the mechanical properties of the coupling.

[0006] The method for testing the angular stiffness and radial stiffness of the diaphragm coupling provided by the present invention can adopt the following technical solutions:

[0007] A test method for the angular stiffness and radial stiffness of a diaphragm coupling, comprising the following steps:

[0008] Step 1: Connect the two ends of the diaphragm coupling to the first adapter and the second adapter respectively. Fasten the first adapter to the test bench, and the second adapter is in a cantilever state;

[0009] Step 2: Determine the pressure application position on the second adapter and adjust the position of the laser displacement sensor. The laser measurement point of the laser displacement sensor is located below the second adapter and coincides with the line of action of the pressure;

[0010] Step 3: Gradually apply pressure to the second adapter through the pressure loading rod, record the values of the pressure sensor and the laser displacement sensor, and obtain the first set of measurement data; the pressure sensor is used to measure the pressure value applied to the second adapter; the laser displacement sensor is used to measure the displacement value of the corresponding measurement point on the second adapter;

[0011] Step 4: Change the pressure application position on the second adapter and adjust the position of the laser displacement sensor. The laser measurement point of the laser displacement sensor is located below the second adapter and coincides with the line of action of the pressure;

[0012] Step 5: Apply pressure to the second adapter step by step again, record the values of the pressure sensor and the laser displacement sensor, and obtain the second set of measurement data; the pressure sensor is used to measure the pressure value applied to the second adapter; the laser displacement sensor is used to measure the displacement value of the corresponding measurement point on the second adapter;

[0013] Step 6: Based on the first set of measurement data and the second set of measurement data, solve the stiffness value according to the stiffness calculation models for the angular and radial directions of the diaphragm coupling.

[0014] Further, in Step 1, the diaphragm coupling is connected to the first adapter and the second adapter through a standard bolt group and tightened according to the torque range required by the coupling technical requirements.

[0015] Further, for the diaphragm coupling for which the angular stiffness and radial stiffness are tested, the thickness of the diaphragm group of the diaphragm coupling is d, and the thickness H of the first adapter and the second adapter is in the range of 4 - 5d; the length dimension of the first adapter is in the range of 6 - 7H, and it is only necessary to ensure the reliable connection between the first adapter and the test bench and the diaphragm coupling; the length dimension of the second adapter is in the range of 7 - 8H. By setting the length and thickness dimensions of the first adapter and the second adapter, it is ensured that the first adapter and the second adapter have greater structural stiffness compared to the diaphragm coupling; and the thickness of the first adapter and the second adapter is limited to be less than 5d, simplifying the size of the test device, reducing the mass, and facilitating installation.

[0016] Further, in Step 2 and Step 4, the pressure is applied in the radial direction of the second adapter, and the lengths L1 and L2 from the first and second pressure application positions to the center of the diaphragm coupling are recorded; the first pressure application position should be close to the center position of the diaphragm coupling, and the length L1 should be less than 2.5H to ensure the smooth application of the pressure loading rod; the second pressure application position should be far from the center position of the diaphragm coupling, and the length L2 is in the range of 6.5 - 7.5H.

[0017] Further, in Step 3 and Step 5, the magnitudes of the gradually applied pressures should be the same, and the pressure magnitude and the laser displacement sensor values at equal pressure magnitudes are recorded.

[0018] Further, in Step 6, for the stiffness calculation models of the angular and radial directions of the diaphragm coupling, based on the first set of measurement data and the second set of measurement data, the angular stiffness of the coupling is solved first, and on this basis, the radial stiffness of the coupling is solved.

[0019] Further, the stiffness calculation model for the angular direction of the diaphragm coupling is:

[0020]

[0021] Further, the stiffness calculation model for the radial direction of the diaphragm coupling is:

[0022] Or

[0023] Wherein, K r is the radial stiffness, K a is the angular stiffness, F is the equal magnitude of the two pressure applications, L1 and x1 are respectively the length from the pressure application position to the center of the diaphragm coupling and the value of the laser displacement sensor in Step 3, and L2 and x2 are the length from the pressure application position to the center of the diaphragm coupling and the value of the laser displacement sensor in Step 5.

[0024] The test method for the angular stiffness and radial stiffness of a diaphragm coupling provided by the present invention has the following beneficial effects:

[0025] 1) Compared with the existing technology, the present invention can simultaneously conduct the test experiments for the angular stiffness and radial stiffness of the diaphragm coupling, and the calculation data of the angular stiffness and radial stiffness of the coupling can be obtained through one experiment, avoiding multiple relatively independent angular stiffness test experiments and radial stiffness test experiments, effectively reducing the experimental time cost and experimental tooling cost, and improving the utilization rate of experimental data.

[0026] 2) By setting the lengths and thicknesses of the first adapter and the second adapter, they have sufficient structural stiffness relative to the diaphragm coupling. When pressure is applied, the deformations of the first adapter and the second adapter relative to the diaphragm coupling are small enough to be regarded as rigid bodies. At this time, the values measured by the laser displacement sensor can be considered as the result of the superposition of only the deformation of the diaphragm coupling and the rigid body displacement of the second adapter, reducing the influence of the deformations of the first adapter and the second adapter on the coupling stiffness test and further ensuring the reliability of the stiffness test principle.

[0027] 3) The stiffness calculation models for the angular and radial directions of the diaphragm coupling of the present invention are based on the displacement data at different loading positions under the action of the same radial pressure, and can obtain the decoupled angular stiffness and radial stiffness, effectively avoiding the mutual influence of the mechanical properties in the angular and radial directions of the coupling; in addition, the first pressure loading position is close to the center of the coupling, and the second pressure loading position is far from the center of the coupling. The two pressure loading positions set not only reduce the length of the second adapter at the non-pressure loading position, but also have a large enough offset to amplify the difference in angular displacement, improving the effectiveness of the stiffness calculation model and ensuring the accuracy of the stiffness test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a flowchart of a method for testing the angular stiffness and radial stiffness of a diaphragm coupling in this embodiment.

[0029] Figure 2 is a schematic diagram of the installation of the diaphragm coupling in this embodiment.

[0030] Figure 3 is a schematic diagram of some dimensional relationships in this embodiment.

[0031] Figure 4 is a schematic diagram of the adjustment of the two pressure application positions and the measurement positions of the laser displacement sensor in this embodiment.

[0032] Figure 5 is a schematic diagram of the process decomposition of the radial displacement and angular displacement in step S3 of this embodiment.

[0033] Figure 6 is a schematic diagram of the process decomposition of the radial displacement and angular displacement in step S5 of this embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To more clearly describe the objectives, technical solutions, and advantages of the specific embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the scope of protection of the present invention.

[0035] This embodiment proposes a test method for the angular stiffness and radial stiffness of a diaphragm coupling. Refer to Figure 2 and Figure 4 As shown, the test device used in this test method includes a first adapter 1, a second adapter 2, and a diaphragm coupling 5 located between the first adapter 1 and the second adapter 2. The first adapter 1 and the second adapter 2 are tightly assembled with the diaphragm coupling 5 through a standard bolt group, and the first adapter 1 is tightly installed on the test bench 8, while the second adapter 2 is in a cantilever state. A pressure loading rod 4 is provided above the second adapter 2, a pressure sensor 6 is installed at the end of the pressure loading rod 4, and a laser displacement sensor 7 is provided below the second adapter 2.

[0036] Combined with Figure 1 As shown, a test method for the angular stiffness and radial stiffness of a diaphragm coupling in this embodiment includes the following steps:

[0037] S1: Connect the two ends of the diaphragm coupling to the first adapter 1 and the second adapter 2 respectively, tightly install the first adapter 1 on the test bench 8, and the second adapter 2 is in a cantilever state.

[0038] Specifically, refer to Figure 2 , which is the installation schematic diagram of the diaphragm coupling in this embodiment. The diaphragm coupling 5 is bolted to the first adapter 1 and the second adapter 2 through a standard bolt group and tightened within the torque range required by the coupling technical requirements to ensure that the diaphragm coupling in the experimental state is consistent with the diaphragm coupling in the working state and avoid the influence of bolts and bolt pre-tightening force on the accuracy of the coupling stiffness experiment.

[0039] Specifically, refer to Figure 3, which is a schematic diagram of partial dimensional relationships in this embodiment. By setting the lengths and thickness dimensions of the first adapter and the second adapter, it is ensured that the first adapter and the second adapter have greater structural stiffness compared to the diaphragm coupling. The thickness of the diaphragm group of the diaphragm coupling is d, and the thickness H dimension of the first adapter and the second adapter is within the range of 4 - 5d; the length dimension of the first adapter is within the range of 6 - 7H, and it is only necessary to ensure a reliable connection between the first adapter and the test bench and the diaphragm coupling. The length dimension of the second adapter is within the range of 7 - 8H. When pressure is applied, the deformation of the first adapter and the second adapter relative to the diaphragm coupling is small enough to be regarded as a rigid body, reducing the influence of the deformation of the first adapter and the second adapter on the coupling stiffness test. In addition, restricting the thickness of the first adapter and the second adapter to be less than 5d simplifies the size of the test device, reduces the mass, and facilitates installation.

[0040] S2: Determine the pressure application position on the second adapter 2 and adjust the position of the laser displacement sensor 7. The laser measurement point of the laser displacement sensor 7 is located below the second adapter 2 and coincides with the line of action of the pressure.

[0041] S3: Gradually apply pressure to the second adapter 2 through the pressure loading rod 4, record the values of the pressure sensor 6 and the laser displacement sensor 7, and obtain the first set of measurement data.

[0042] Specifically, the pressure sensor 6 is used to measure the pressure value applied to the second adapter 2, and the laser displacement sensor 7 is used to measure the displacement value of the corresponding measurement point on the second adapter 2.

[0043] S4: Change the pressure application position on the second adapter 2 and adjust the position of the laser displacement sensor 7. The laser measurement point of the laser displacement sensor 7 is located below the second adapter 2 and coincides with the line of action of the pressure.

[0044] Specifically, refer to Figure 4 , which is a schematic diagram of the adjustment of the pressure application positions and the measurement positions of the laser displacement sensor 7 in steps S2 and S4. The pressure is applied in the radial direction of the second adapter 2, and the lengths L1 and L2 of the two pressure positions from the center of the diaphragm coupling need to be recorded.

[0045] Specifically, the first pressure application position should be close to the center position of the diaphragm coupling, and the length L1 should be less than 2.5H, and ensure the smooth loading of the pressure loading rod; the second pressure application position should be far from the center position of the diaphragm coupling, and the length L2 is within the range of 6.5 - 7.5H. The two set pressure application positions have a large offset, amplifying the angular displacement difference between the results of the two pressure applications; at the same time, reducing the length of the second adapter without pressure application position improves the effectiveness of the stiffness calculation model and ensures the accuracy of the stiffness test results.

[0046] S5: Apply pressure to the second adapter 2 step by step again, record the values of the pressure sensor 6 and the laser displacement sensor 7, and obtain the second set of measurement data.

[0047] Specifically, the pressure amplitudes applied step by step in step S3 and step S5 should be the same. Record the values of the laser displacement sensors in step S3 and step S5 under the action of the pressure amplitude F, which are x1 and x2 respectively.

[0048] S6: Based on the first set of measurement data and the second set of measurement data, solve the stiffness value according to the calculation model of the angular and radial stiffness of the diaphragm coupling.

[0049] Specifically, for the calculation model of the angular and radial stiffness of the diaphragm coupling, based on the first set of measurement data and the second set of measurement data, first solve the angular stiffness of the coupling, and then solve the radial stiffness of the coupling on this basis.

[0050] Specifically, refer to Figure 5 、 Figure 6 , which are the schematic diagrams of the process decomposition of the radial displacement and angular displacement in step S3 and step S5 respectively. The thick solid line represents the initial position of the second adapter, the thin solid line represents the position where the second adapter first undergoes radial displacement, and the dotted line represents the position where the second adapter then undergoes angular displacement.

[0051] For different pressure application positions L1 and L2, under the action of the same pressure amplitude F, the radial displacement amounts of the second adapter are equal, both being Δy. On the premise of a small rotation angle, there are the following geometric relationships:

[0052] x1 = Δy + Δx1; ①

[0053] Δx1 = L1 * θ1; ②

[0054] x2 = Δy + Δx2; ③

[0055] Δx2 = L2 * θ2; ④

[0056] Among them, under the action of the pressure amplitude F, the values of the laser displacement sensors for the two loadings are x1 and x2 respectively; from the radial displacement position to the angular displacement position in the displacement process decomposition, the angular displacement amounts are θ1 and θ2 respectively, and the radial displacement amounts generated by this angular displacement on the pressure action line are Δx1 and Δx2 respectively.

[0057] To achieve the decoupling of the calculation of the angular stiffness and the radial stiffness, it is necessary to eliminate the pure radial displacement amount △y generated by the action of the pressure F. Combine equations ①, ②, ③, and ④ to obtain

[0058] x2 - x1 = L2 * θ2 - L1 * θ1; ⑤

[0059] For the angular stiffness Ka , the radial stiffness K r There is the following linear stiffness model:

[0060]

[0061]

[0062] By combining equations ⑤ and ⑥, the angular stiffness calculation model of the diaphragm coupling can be obtained:

[0063]

[0064] On this basis, by combining equations ①, ②, ⑦, and ⑧, the radial stiffness calculation model of the diaphragm coupling can be obtained:

[0065]

[0066] The test method for the angular stiffness and radial stiffness of the diaphragm coupling is reasonable, and the angular stiffness and radial stiffness can be tested simultaneously; the stiffness calculation model is reliable, which can realize the decoupling of the angular stiffness and radial stiffness, and further ensures the effectiveness and accuracy of the calculation model by setting the test device and test method.

[0067] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present invention is defined by the appended claims rather than the above description.

[0068] The above-described embodiments are some embodiments of the present invention, rather than all embodiments, and the protection scope of the present invention is not limited thereto. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

Claims

1. A test method for the angular stiffness and radial stiffness of a diaphragm coupling, characterized in that It includes the following steps: Step 1: Connect both ends of the diaphragm coupling to the first adapter and the second adapter respectively. Fasten the first adapter to the test bench, and the second adapter is in a cantilever state. For the diaphragm coupling for angular stiffness and radial stiffness testing, the thickness of the diaphragm group of the diaphragm coupling is d, and the thickness H of the first adapter and the second adapter is in the range of 4 - 5d. The length dimension of the first adapter is in the range of 6 - 7H, ensuring a reliable connection between the first adapter, the test bench, and the diaphragm coupling. The length dimension of the second adapter is in the range of 7 - 8H. By setting the length and thickness dimensions of the first adapter and the second adapter, it is ensured that the first adapter and the second adapter have greater structural stiffness compared to the diaphragm coupling. Step 2: Determine the pressure application position on the second adapter and adjust the position of the laser displacement sensor. The laser measurement point of the laser displacement sensor is located below the second adapter and coincides with the line of action of the pressure. Step 3: Gradually apply pressure to the second adapter through the pressure loading rod, and record the values of the pressure sensor and the laser displacement sensor to obtain the first set of measurement data. The pressure sensor is used to measure the pressure value applied to the second adapter. The laser displacement sensor is used to measure the displacement value of the corresponding measurement point on the second adapter. Step 4: Change the pressure application position on the second adapter and adjust the position of the laser displacement sensor. The laser measurement point of the laser displacement sensor is located below the second adapter and coincides with the line of action of the pressure. Step 5: Apply pressure to the second adapter step by step again, and record the values of the pressure sensor and the laser displacement sensor to obtain the second set of measurement data. The pressure sensor is used to measure the pressure value applied to the second adapter. The laser displacement sensor is used to measure the displacement value of the corresponding measurement point on the second adapter. Step 6: Based on the first set of measurement data and the second set of measurement data, solve the stiffness value according to the angular and radial stiffness calculation models of the diaphragm coupling. The angular stiffness calculation model of the diaphragm coupling is: where K a is the angular stiffness, F is the equal amplitude of the two pressure loadings, L1 and x1 are respectively the lengths of the pressure loading positions from the center of the diaphragm coupling and the values of the laser displacement sensors in Step 3, and L2 and x2 are the lengths of the pressure loading positions from the center of the diaphragm coupling and the values of the laser displacement sensors in Step 5; The radial stiffness calculation model of the diaphragm coupling is: Among them, K r is the radial stiffness, and K a is the angular stiffness. F is the equal amplitude of the two pressure loadings. L1 and x1 are respectively the length of the pressure loading position from the center of the diaphragm coupling and the value of the laser displacement sensor in step three; In Step 2 and Step 4, the pressure is applied in the radial direction of the second adapter, and record the lengths L1 and L2 of the first and second pressure application positions from the center of the diaphragm coupling. The first pressure application position should be close to the center position of the diaphragm coupling, and the length L1 should be less than 2.5H to ensure the smooth loading of the pressure loading rod. The second pressure application position should be far from the center position of the diaphragm coupling, and the length L2 is in the range of 6.5 - 7.5H.

2. The test method according to claim 1, characterized in that, In Step 1, the diaphragm coupling is connected to the first adapter and the second adapter through a standard bolt group and tightened according to the torque range required by the coupling technical requirements.

3. The test method according to claim 1, characterized in that, In Step 3 and Step 5, the gradually applied pressure amplitudes should be the same, and record the pressure amplitude and the values of the laser displacement sensor under the equal pressure amplitude.

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