Disc spring design method

Abstract

The invention belongs to the technical field of disc spring design, and particularly relates to a disc spring design method. The disc spring design method comprises the steps that the inner cone height of a disc spring is h, the thickness of the disc spring is t, the working stroke interval of the disc spring is Y, and the deformation quantity of a sealing gasket corresponding to the critical value of leakage of the sealing gasket is X; the h value and the t value are selected according to the following conditions: the condition 1: (h-KX) < = Y < = h, 0lt; klt; according to the condition 1, F1'is the load corresponding to the stroke (h-KX) of the disc spring, F2 'is the load corresponding to the stroke h of the disc spring, and according to the condition 2, in the interval section of F1'-F2 ', the deformation X1 of the sealing gasket, the deformation X2 of the disc spring, the K1 of the compression sealing section of the sealing gasket and the K2 of the effective compensation section of the disc spring, K1 = (F1'-F2 ') / X1, K2 = (F1'-F2 ') / X2, and K2 is larger than 0 and smaller than K1, so that the disc spring obtained through design can play a compensation role on the sealing gasket.

Description

Technical Field

[0001] The present application belongs to the technical field of disc spring design, and in particular relates to a disc spring design method. Background Art

[0002] The disc spring's anti-loosening mechanism is that when the thread loosens, its wedge angle design increases the preload, which in turn reduces the thread slip area and reduces loosening, creating a negative feedback regulation effect. Although the disc spring has a good effect on thread loosening, this effect is due to the combination of friction and mechanical anti-loosening. The disc spring's upper and lower surfaces form a radial tooth structure, which can damage the nut and the surface of the equipment body. Moreover, when used in sealing structures, it cannot compensate for the plastic deformation, creep, and stress redistribution of the bolts and gaskets. During torque tightening, if the nut rotates, torque compensation occurs, resulting in false torque. How to enable disc springs to provide sealing force compensation when used in sealing structure tightening is an important research topic.

[0003] The above statements are only used to provide background information related to the present application and do not necessarily constitute prior art. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a disc spring design method, wherein the designed disc spring has a sealing force compensation function.

[0005] The technical solution adopted in the embodiment of the present application is: a disc spring design method, the disc spring is used to cooperate with the sealing gasket and the bolt; the disc spring design method includes:

[0006] The load F of a single bolt corresponding to the minimum sealing stress of the selected gasket L1 ;

[0007] The load F of a single bolt corresponding to the maximum sealing stress of the selected gasket L2 , the deformation of the sealing gasket corresponding to the critical value of leakage is X;

[0008] The preset load range of the gasket corresponds to the load of a single bolt of F1 to F2;

[0009] According to F L1 <F1'<F2'<F1<F2<F L2 , we can get, F1'=b*F L1 , F1=b*F2', b>1;

[0010] Select the b value and get the values ​​of F1' and F2';

[0011] The inner cone height of the disc spring is h, the thickness of the disc spring is t, the working stroke range of the disc spring is Y, and the deformation of the gasket corresponding to the critical value of leakage is X;

[0012] Select the values of h and t according to the following conditions,

[0013] Condition 1: (h - KX) ≤ Y ≤ h, 0 < K < 1, and F1’ is the load corresponding to the disc spring at the stroke (h - KX), and F2’ is the load corresponding to the disc spring at the stroke h;

[0014] Condition 2: In the range of F1’ to F2’, the deformation of the gasket is X1, the deformation of the disc spring is X2, the K1 of the compression sealing section of the gasket, and the K2 of the effective compensation section of the disc spring. Among them, K1 = (F1’ - F2’) / X1, K2 = (F1’ - F2’) / X2; 0 < K2 < K1.

[0015] Optionally, 0 < K2 ≤ 0.1.

[0016] Optionally, obtain F according to the unloading sealing curve of the gasket L1 and F L2 .

[0017] Optionally, the elastic modulus of the disc spring is greater than the elastic modulus of the bolt.

[0018] Optionally, before selecting the values of h and t, determine the inner diameter d and outer diameter D of the disc spring according to the mounting hole of the bolt and the length of the bolt. The inner diameter d of the disc spring is greater than the diameter of the mounting hole and the rod diameter of the bolt, and the disc spring does not protrude from the outer peripheral surface of the equipment to be sealed when the stroke is h.

[0019] Optionally, before installing the disc spring, the length of the bolt protruding from the nut is L. Selecting the values of h and t includes: selecting multiple values of h, and h = 0.5N, where N is a positive integer; from the selected multiple values of h, select the values of h that satisfy h + t ≤ L to form a preliminary combination of h values; according to F2’, d and D, substitute each value of h in the preliminary combination of h values into the disc spring load calculator to calculate the corresponding value of t, and form a combination of h values and t values. From the combination of h values and t values, select the values of h and t that satisfy the condition of h + t ≤ L, and form a preliminary combination of h values and t values.

[0020] Optionally, according to F1’, d and D, substitute each pair of h values and t values in the preliminary combination of h values and t values into the disc spring load calculator, and select the values of h and t that satisfy the condition of​​Optionally, among the useful combinations of h values and t values, select the h values and t values that meet the stress preset conditions, and form valid combinations of h values and t values. According to the valid combinations of h values and t values, obtain multiple load curves. According to the multiple load curves, screen out the intervals within F1' to F2' where 0 < K2 < K1, so as to obtain the final combination of h values and t values.

[0022] Optionally, select some combinations of h values and t values from the combinations of h values and t values that do not meet the stress preset conditions. By adjusting the h values and t values, calculate the adjusted h values and t values, and select the h values and t values that meet the stress preset conditions, h + t ≤ L, b > 1, 0 < K < 1, and 0 < K2 < K1, and add the selected h values and t values to the final combination of h values and t values;

[0023] And / or, select from the combinations of h values and t values that do not meet the stress preset conditions by adjusting the b value, and select the h values and t values that meet the stress preset conditions, h + t ≤ L, b > 1, 0 < K < 1, and 0 < K2 < K1, and add the selected h values and t values to the final combination of h values and t values.

[0024] Optionally, fabricate a prototype disc spring according to the final combination of h and t values, conduct a fatigue test on the prototype disc spring, and screen out the prototype disc springs that meet the reciprocating compression test range from (h - KX) to h, with the requirement that the fatigue test life ≥ G million times, where G > 1.

[0025] One or more of the above technical solutions in the disc spring design method provided by the embodiments of the present application at least have the following technical effects: In the disc spring design method of the embodiments of the present application, through Condition 1: (h - KX) ≤ Y ≤ h, 0 < K < 1, where F1' is the load corresponding to the disc spring at the stroke (h - KX), and F2' is the load corresponding to the disc spring at the stroke h; and Condition 2: within the interval of F1' to F2', the deformation amount X1 of the gasket, the deformation amount X2 of the disc spring, the K1 of the compression sealing section of the gasket, and the K2 of the effective compensation section of the disc spring, where K1 = (F1' - F2') / X1, K2 = (F1' - F2') / X2; 0 < K2 < K1, the h values and t values of the disc spring are selected, so that the obtained disc spring can play a compensation role for the gasket. Especially through the design of 0 < K2 < K1, X2 > X1 (because K = ΔF / ΔX, the smaller K is, the larger the deformation amount ΔX is). When the equipment causes the gasket to undergo a small deformation (X1) due to factors such as vibration and temperature change, the disc spring will absorb the load fluctuation through a larger deformation amount (X2), and utilize the elastic deformation characteristics of the disc spring to compensate for the gasket relaxation in real time, improving the reliability of the gasket under working conditions such as vibration and temperature change.

[0026] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0028] Figure 1 Schematic diagram of the installation of disc springs and sealing gaskets provided in some embodiments of the present application.

[0029] Figure 2 A cross-sectional view of a disc spring provided for some embodiments of the present application.

[0030] Figure 3 Loading and unloading curves of the sealing gasket provided in some embodiments of the present application.

[0031] Figure 4 Load curves of different disc springs provided for some embodiments of the present application.

[0032] Among them, the reference numerals in the figures are:

[0033] 10. Flange; 20. Bolt; 30. Nut; 40. Disc spring; 50. Gasket. DETAILED DESCRIPTION

[0034] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0035] In the description of the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one of such features.

[0036] In the description of the present application, “a plurality of” means at least two, for example, two, three, etc., unless otherwise clearly defined.

[0037] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; they can refer to direct connection or indirect connection through an intermediate medium; they can refer to internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0038] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0039] In the description of the present application, it should be understood that the terms "inside", "outside", "side", "top", "bottom", "front", "back", etc., indicating directions or positional relationships, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0040] In the description of this application, it should be noted that the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0041] It should also be noted that, in the embodiments of the present application, the same figure mark represents the same component or the same part. For the same parts in the embodiments of the present application, the figure may only mark one of the parts or components as an example. It should be understood that the figure mark also applies to other identical parts or components.

[0042] The anti-loosening mechanism of the disc spring is that when the thread is loose, its wedge angle design increases the preload force, which in turn reduces the thread slip area and reduces the loosening, which is a negative feedback regulation effect. Although the disc spring anti-loosening has a good effect on preventing thread loosening, the reason for this effect is the coordination of friction and mechanical anti-loosening. The upper and lower surfaces of the disc spring form a radial tooth structure, which can cause damage to the nut and the surface of the equipment body. Moreover, when used in a sealing structure, it has no compensation effect on the plastic deformation, creep, and stress redistribution of the bolts and gaskets. During torque tightening, if the nut rotates and torque compensation occurs, false torque will occur.

[0043] Especially in nuclear power plants, the flanges of two devices are connected by bolts, with a gasket located between the two flanges. The gasket is used to achieve a sealed connection between the two devices. However, the leakage risk of the flange connection system stems from the insufficient elastic deformation of the gasket. When the bolt load decreases due to factors such as temperature fluctuations and vibration, the compression of the gasket decreases, and the sealing interface stress falls below the critical value, resulting in medium leakage. In some designs, high preload is relied upon, but this will aggravate the creep relaxation of the gasket. Therefore, when the gasket compression decreases, how the disc spring can compensate for this deformation to achieve a stable seal between the two devices is an important research topic.

[0044] Based on this, an embodiment of the present application proposes a disc spring design method. The disc spring obtained by applying this method can compensate for the sealing force of the sealing structure and prevent loosening, and also considers the sealing margin design when the disc spring creeps or cracks.

[0045] The following combination Figures 1 to 4 The disc spring design method of the embodiment of the present application is described.

[0046] In some embodiments, a disc spring design method is provided, wherein the disc spring 40 is used to cooperate with the sealing gasket 50 and the bolt 20. The disc spring design method includes:

[0047] The load F of a single bolt 20 corresponding to the minimum sealing stress of the selected sealing gasket 50 is L1 ;

[0048] The load F of a single bolt 20 corresponding to the maximum sealing stress of the selected sealing gasket 50 L2 , when the sealing gasket 50 reaches the critical value of leakage, the corresponding deformation amount of the sealing gasket 50 is X;

[0049] The preset load range of the sealing gasket 50 corresponds to the load range of the single bolt 20 being F1 to F2;

[0050] According to F L1 <F1'<F2'<F1<F2<F L2 , we can get, F1'=b*FL1 , F1 = b * F2’, b > 1;

[0051] Select the value of b to obtain the values of F1’ and F2’;

[0052] The inner conical height of the disc spring 40 is h, the thickness of the disc spring 40 is t, the working stroke interval of the disc spring 40 is Y, and the deformation amount of the gasket 50 corresponding to the critical value of leakage is X;

[0053] Select the values of h and t according to the following conditions,

[0054] Condition 1: (h - KX) ≤ Y ≤ h, 0 < K < 1, and F1’ is the load corresponding to the disc spring 40 at the stroke (h - KX), and F2’ is the load corresponding to the disc spring 40 at the stroke h;

[0055] Condition 2: In the interval of F1’ to F, the deformation amount of the gasket 50 is X1, the deformation amount of the disc spring 40 is X2, the K1 of the compression sealing section of the gasket 50, and the K2 of the effective compensation section of the disc spring 40, where K1 = (F1’ - F2’) / X1, K2 = (F1’ - F2’) / X2; 0 < K < K1.

[0056] A plurality of bolts 20 are provided circumferentially on the flange 10, and the minimum sealing stress of the gasket 50 can be decomposed onto the plurality of bolts 20, so as to obtain the load F of a single bolt 20 L1 , Similarly, the maximum sealing stress of the gasket 50 can also be decomposed onto the plurality of bolts 20, so as to obtain the load F of a single bolt 20 L2 .

[0057] F L1 can refer to the load of the minimum sealing stress of the gasket 50 decomposed onto a single bolt 20, that is, the lowest pre-tightening force of a single bolt 20 to maintain sealing. If the actual load is lower than F L1 , the gasket 50 cannot be sealed and leakage occurs.

[0058] F L2 can refer to the load of the maximum sealing stress of the gasket 50 decomposed onto a single bolt 20, that is, the pressing force provided by a single bolt 20 converted from the maximum safe pre-tightening force that the gasket 50 material can withstand. If the actual load exceeds F L2 it will cause damage to the gasket 50.

[0059] When the stress of the gasket 50 is F L2 , the deformation amount of the gasket 50 is X, and at this time the sealing performance of the gasket 50 drops to the critical value.

[0060] The preset load range of the gasket 50 can refer to the actual working load range of the gasket 50. By decomposing this load range onto a single bolt 20, F1 to F2 can be obtained.

[0061] Inner cone height h: The initial height of the disc spring 40 when it is not under load, which determines its maximum compressible stroke (the stroke is h when it is fully compressed).

[0062] Thickness t: The thickness of the disc spring 40 when it is fully compressed.

[0063] Working stroke interval Y: The deformation range in which the disc spring 40 actually works, and it needs to satisfy: (h - KX) ≤ Y ≤ h (0 < K < 1), and 0 < K < 1, so that the compensation deformation amount given by the disc spring 40 to the gasket 50 does not exceed the critical value X of the leakage deformation of the gasket 50, and the gasket 50 can achieve a good sealing effect. When the disc spring 40 bursts, it will not cause leakage of the gasket 50.

[0064] h - KX: The minimum working stroke of the disc spring 40.

[0065] h: The maximum stroke of the disc spring 40 (fully compressed state, without compensation ability).

[0066] Load parameters:

[0067] F1': The load of the disc spring 40 at the stroke h - KX.

[0068] F2': The load of the disc spring 40 at the stroke h (the maximum load when fully compressed).

[0069] F L1 <F1’<F2’<F1<F2<F L2 , it can be understood that F L1 <F1’: Ensure that the minimum working load F1’ of the disc spring 40 is higher than the minimum sealing stress load F of the gasket 50 L1 , to avoid initial leakage of the gasket 50 due to insufficient load.

[0070] F2’<F1: The maximum working load F2’ of the disc spring 40 needs to be less than the load F1 decomposed from the preset minimum working load of the gasket 50 onto a single bolt 20, so that the disc spring 40 provides "buffer compensation" for the gasket 50 within the elastic deformation range, rather than directly bearing the main load.

[0071] F2<F L2 : The load F2 decomposed from the preset maximum load of the gasket 50 onto a single bolt 20 needs to be lower than the leakage critical load F L2 , to prevent the gasket 50 from failing due to excessive compression.

[0072] F1’ = b * F L1, considering that the disc spring 50 may have creep, fatigue, and a reduced elastic modulus at high temperatures, which may cause F1' to be higher than the minimum sealing requirement of the gasket 50. A safety margin is reserved.

[0073] F1 = b * F2', where F1 is higher than the maximum compensation force F2' of the disc spring 40, so that the disc spring 40 can be fully compressed after being installed in place, and also so that when the axial force of the bolt 20 decays, the compensation load range of the disc spring 40 is greater than F L1 , and there is sufficient compensation margin.

[0074] The selection of b can be determined by considering the elastic modulus of the material of the gasket 50, the stiffness of the disc spring 40, and the vibration / shock conditions of the sealing equipment. Usually, it is optimized through experiments or simulations so that the disc spring 40 can compensate for the deformation of the gasket 50 within the working stroke without exceeding its elastic limit.

[0075] K1 = (F1' - F2') / X1, where K1 reflects the ability of the gasket 50 to resist compressive deformation, and X1 is the deformation of the gasket 50 within the load range (F1'~F2').

[0076] K2 = (F1' - F2') / X2, where K2 reflects the ability of the disc spring 40 to compensate for load fluctuations through elastic deformation, and X2 is the deformation of the disc spring 40 within the load range (F1'~F2').

[0077] The disc spring design method of the embodiment of the present application, through condition 1: (h - KX) ≤ Y ≤ h, 0 < K < 1, where F1' is the load corresponding to the disc spring 40 at the stroke (h - KX), and F2' is the load corresponding to the disc spring 40 at the stroke h; and condition 2: within the F1'~F2' interval, the deformation X1 of the gasket 50, the deformation X2 of the disc spring 40, K1 of the compression sealing section of the gasket 50, and K2 of the effective compensation section of the disc spring 40, where K1 = (F1' - F2') / X1, K2 = (F1' - F2') / X2; 0 < K2 < K1, select the h value and t value of the disc spring 40 so that the obtained disc spring 40 can compensate for the gasket 50. Especially through the design of 0 < K2 < K1, X2 > X1 (because K = ΔF / ΔX, the smaller K is, the larger the deformation ΔX is). When the equipment causes the gasket 50 to have a small deformation (X1) due to factors such as vibration and temperature change, the disc spring 40 will absorb the load fluctuation through a larger deformation (X2), utilize the elastic deformation characteristics of the disc spring 40, and compensate for the relaxation of the gasket 50 in real time, improving the reliability of the gasket 50 under conditions such as vibration and temperature change.

[0078] In some embodiments, 0 < K2 ≤ 0.1.

[0079] The value of K2 may be 0.1 or any value between 0 and 0.1; for example, the value of K2 may be, but is not limited to, 0.01, 0.02, 0.03, 0.05, 0.07, or 0.1.

[0080] By adopting the technical solution of this embodiment, when the sealing gasket 50 undergoes a small deformation, the disc spring 40 can undergo a large deformation absorption displacement, so that the sealing gasket 50 is always in an effective sealing state.

[0081] In some embodiments, the F is obtained based on the unloading sealing curve of the sealing gasket 50. L1 and F L2 .

[0082] The unloading sealing curve of the sealing gasket 50 may refer to a relationship curve between the stress (or load) and the deformation amount of the sealing gasket 50 when the load gradually decreases after the sealing gasket 50 bears a load.

[0083] For example, the unloading sealing curve of the sealing gasket 50 can be found in Figure 3 The curve on the right side, F L1 and F L2 The load of the single bolt 20 corresponding to point P and the vertex of the right curve can be taken respectively.

[0084] In some embodiments, the elastic modulus of the disc spring 40 is greater than the elastic modulus of the bolt 20, so that the deformation effect of the disc spring 40 is reduced when the sealing system is pressurized (i.e., when the two flanges 10 are relatively far apart), thereby minimizing the negative impact of the disc spring 40 on the seal when the sealing system is pressurized.

[0085] In some embodiments, see Figure 2 As shown, before selecting the h value and t value, the inner diameter d and outer diameter D of the disc spring 40 are determined according to the mounting hole of the bolt 20 and the length of the bolt 20. The inner diameter d of the disc spring 40 is larger than the hole diameter of the mounting hole and the rod diameter of the bolt 20. The disc spring 40 does not protrude from the outer peripheral surface of the device to be sealed when the stroke is h.

[0086] The mounting hole may refer to a hole on the flange 10 for the bolt 20 to pass through.

[0087] The shank diameter of the bolt 20 may refer to the diameter of the threaded section of the bolt 20 .

[0088] The height of the disc spring 40 is H.

[0089] The inner diameter d of the disc spring 40 is greater than the diameter of the mounting hole, which can reduce the risk of interference between the disc spring 40 and the wall of the mounting hole; the inner diameter d of the disc spring 40 is greater than the rod diameter of the bolt 20, so as to ensure that the bolt 20 passes through the inner hole of the disc spring 40 without getting stuck. The inner diameter d of the disc spring 40 needs to be greater than the maximum value of the two to facilitate assembly.

[0090] When the stroke of the disc spring 40 is h, it does not protrude from the outer peripheral surface of the equipment to be sealed (for example, the outer peripheral surface of the flange 10, etc.), reducing the interference between the disc spring 40 and other components, improving the appearance flatness of the equipment sealing connection, enabling the disc spring 40 to be stressed over the entire surface, reducing the stress uniformity of the disc spring 40, and improving the service reliability of the disc spring 40.

[0091] In some embodiments, D and d can also be appropriately adjusted according to the compensation performance of the disc spring 40.

[0092] In some embodiments, before the disc spring 40 is installed, the length that the bolt 20 protrudes from the nut 30 is L. Selecting the h value and the t value includes: selecting multiple h values, and h = 0.5N, where N is a positive integer; from the selected multiple h values, selecting the h values that satisfy h + t ≤ L to form a preliminary combination of h values; according to F2', d, and D, substituting each h value in the preliminary combination of h values into the disc spring 40 load calculator to calculate the corresponding t value, and forming a combination of h values and t values, and from the combination of h values and t values, selecting the h values and t values that satisfy the condition of h + t ≤ L, and forming a preliminary combination of h values and t values.

[0093] L represents the length that the bolt 20 extends beyond the end face of the nut 30 after passing through the connected parts (such as flanges, equipment bodies, etc.) when the disc spring 40 is not installed. This length reflects the installation space reserved for the disc spring 40 by the bolt 20.

[0094] h can take integer multiples of 0.5 to obtain multiple h values. The selected h values need to satisfy the condition of h + t ≤ L, so that a limited number of h values can be selected; at the same time, then substituting each h value into the formula recorded in C.3.1 of GB / T1972 - 2005, the corresponding t value can be obtained, and a combination of multiple pairs of h values and t values is formed, and then selecting the combination of h values and t values that satisfy h + t ≤ L from the combination of multiple pairs of h values and t values, thereby forming a preliminary combination of h values and t values.

[0095] Through the design of h + t ≤ L, after the disc spring 40 is sleeved on the screw of the bolt 20, the screw of the bolt 20 can be smoothly helically engaged in the nut 30, reducing the risk that the disc spring 40 cannot be fully installed due to the too short screw of the bolt 20.

[0096] In some embodiments, according to F1', d, and D, substituting each pair of h values and t values in the preliminary combination of h values and t values into the disc spring 40 load calculator, selecting the h values and t values that satisfy the condition of 0 < K < 1, and forming a useful combination of h values and t values.

[0097] Substitute the h - value and t - value of each pair in the preliminary h - value and t - value combinations into the formula described in C.3.1 of GB / T 1972 - 2005 to calculate 0 < K < 1; if the calculation shows that the condition 0 < K < 1 is not satisfied, then remove this pair of h - value and t - value; if the calculation shows that the condition 0 < K < 1 is satisfied, retain this pair of h - value and t - value. The multiple pairs of h - value and t - value that satisfy the condition 0 < K < 1 form a useful h - value and t - value combination.

[0098] In some embodiments, from the useful h - value and t - value combination, select the h - value and t - value that satisfy the stress preset condition, and form an effective h - value and t - value combination. According to the effective h - value and t - value combination, obtain multiple load curves (refer to Figure 4 as shown), and according to the multiple load curves, screen out those that satisfy 0 < K2 < K1 in the interval of F1’ - F2’, so as to obtain the final h - value and t - value combination.

[0099] Substitute the h - value and t - value of each pair in the useful h - value and t - value combination into C.3.2 of GB / T 1972 - 2005 to calculate the stress, screen out the multiple pairs of h - value and t - value with smaller stress, and form an effective h - value and t - value combination. Then, according to the h - value and t - value of each pair in the effective h - value and t - value combination, make multiple load curves. According to the multiple load curves, screen out those that satisfy 0 < K2 < K1 in the interval of F1’ - F2’, so as to obtain the final h - value and t - value combination, making the designed disc spring 40 able to play a role in compensating the sealing force of the gasket 50. At the same time, the stress of the disc spring 40 is small, improving the service reliability of the disc spring 40.

[0100] In some embodiments, select some h - value and t - value combinations from the h - value and t - value combinations that do not satisfy the stress preset condition, adjust the h - value and t - value, calculate the adjusted h - value and t - value, and select the h - value and t - value that satisfy the stress preset condition, h + t ≤ L, b > 1, 0 < K < 1, and 0 < K2 < K1, and add the selected h - value and t - value to the final h - value and t - value combination.

[0101] For some h - value and t - value combinations with large stress, that is, those that do not satisfy the stress preset condition, the h - value and t - value can be adjusted, and the adjusted h - value and t - value combination can be calculated. If the calculated h - value and t - value satisfy the above conditions, the adjusted h - value and t - value can also be added to the final h - value and t - value combination. In this way, more disc springs 40 that meet the deformation compensation requirements of the gasket 50 can be obtained.

[0102] In some embodiments, select the h - value and t - value that satisfy the stress preset condition, h + t ≤ L, b > 1, 0 < K < 1, and 0 < K2 < K1 by adjusting the b - value from the h - value and t - value combinations that do not satisfy the stress preset condition, and add the selected h - value and t - value to the final h - value and t - value combination.

[0103] By adjusting the value of b, from the combinations of h values and t values that do not meet the stress preset conditions, select some combinations of h values and t values, calculate the selected combinations of h values and t values, and select the combinations of h values and t values that meet the stress preset conditions, h + t ≤ L, b > 1, 0 < K < 1, and 0 < K2 < K1, and add the selected combinations of h values and t values to the final combinations of h values and t values. In this way, more disc springs 40 that meet the deformation compensation requirements of the gasket 50 can be obtained.

[0104] In some embodiments, from the combinations of h values and t values that do not meet the stress preset conditions, select some combinations of h values and t values. By adjusting the h values and t values, calculate the adjusted h values and t values, and select the h values and t values that meet the stress preset conditions, h + t ≤ L, b > 1, 0 < K < 1, and 0 < K2 < K1, and add the selected h values and t values to the final combinations of h values and t values; from the combinations of h values and t values that do not meet the stress preset conditions, by adjusting the value of b, select the h values and t values that meet the stress preset conditions, h + t ≤ L, b > 1, 0 < K < 1, and 0 < K2 < K1, and add the selected h values and t values to the final combinations of h values and t values. From the combinations of h values and t values that do not meet the stress preset conditions, by simultaneously adjusting the h values, t values, and b values, more disc springs 40 that meet the deformation compensation requirements of the gasket 50 can be obtained.

[0105] In some embodiments, a prototype disc spring is manufactured according to the final combination of h and t values, and a fatigue test is performed on the prototype disc spring to screen out the prototype disc spring that meets the reciprocating compression in the test range from (h - KX) to h, and the fatigue test life is required to be ≥ G million times, where G > 1.

[0106] During the replacement cycle of the gasket 50 under the static load condition, the number of axial cyclic compressions of the gasket 50 is less than 10,000 times. The designed prototype disc spring can reciprocate and compress in the test range from (h - KX) to h, and the number of compressions can reach more than 10,000 times, which can fully meet the usage requirements of the gasket 50.

[0107] The disc spring 40 provided by the embodiment of the present application can compensate for the deformation, creep, and stress redistribution of the bolt 20 and the gasket 50, improving the equipment sealing reliability. In some cases, nuclear power plants use double-ear stop gaskets, which are difficult to replace and time-consuming. The disc spring 40 provided by the present application is installed quickly and has high efficiency; the sealing loop integrity of the equipment applied with the disc spring 40 and the gasket 50 is good, improving the safety level of the nuclear power plant operation system, greatly reducing the equipment leakage defects, and reducing the gasket 50 spare part replacement cost and equipment maintenance cost.

[0108] The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced with each other and will not be repeated herein for the sake of brevity.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A method for designing a disc spring, wherein the disc spring is used to cooperate with a sealing gasket and a bolt; characterized in that: The disc spring design method includes: Select the load F of a single bolt corresponding to the minimum sealing stress of the sealing gasket L1 ; Select the load F of a single bolt corresponding to the maximum sealing stress of the sealing gasket L2 , the deformation amount of the sealing gasket corresponding to the critical value of leakage is X; The load range of a single bolt corresponding to the preset load range of the gasket is F1 to F2; According to F L1 <F1'<F2'<F1<F2<F L2 , we can get, F1'=b*F L1 , F1=b*F2', b>1; Select the value of b to obtain the values of F1' and F2'; The inner cone height of the disc spring is h, the thickness of the disc spring is t, the working stroke range of the disc spring is Y, and the deformation of the gasket corresponding to the critical value of leakage of the gasket is X; Select the values of h and t according to the following conditions, Condition 1: (h - KX) ≤ Y ≤ h, 0 < K < 1, and F1' is the load corresponding to the disc spring at the stroke (h - KX), and F2' is the load corresponding to the disc spring at the stroke h; Condition 2: In the interval of F1' to F2', the deformation of the gasket is X1, the deformation of the disc spring is X2, K1 of the compression sealing section of the gasket, and K2 of the effective compensation section of the disc spring, where K1 = (F1' - F2') / X1, K2 = (F1' - F2') / X2; 0 < K2 < K1.

2. The disc spring design method according to claim 1, characterized in that: 0＜K2≤0.1。 3. The disc spring design method according to claim 1, wherein: According to the unloading sealing curve of the sealing gasket, F L1 and F L2 .

4. The disc spring design method according to claim 1, wherein: The elastic modulus of the disc spring is greater than the elastic modulus of the bolt.

5. The disc spring design method according to any one of claims 1 to 4, characterized in that: Before selecting the values of h and t, according to the mounting hole of the bolt and the length of the bolt, determine the inner diameter d and the outer diameter D of the disc spring. The inner diameter d of the disc spring is greater than the diameter of the mounting hole and the rod diameter of the bolt, and the disc spring does not protrude from the outer peripheral surface of the equipment to be sealed when the stroke is h.

6. The disc spring design method according to claim 5, characterized in that: Before installing the disc spring, the length of the bolt protruding from the nut is L. The selection of the values of h and t includes: selecting multiple values of h, and h = 0.5N, where N is a positive integer; from the selected multiple values of h, select the values of h that satisfy h + t ≤ L to form a preliminary combination of h values; according to F2', d, and D, substitute each value of h in the preliminary combination of h values into the disc spring load calculator to calculate the corresponding value of t, and form a combination of h values and t values. From the combination of h values and t values, select the values of h and t that satisfy the condition of h + t ≤ L, and form a preliminary combination of h values and t values.

7. The disc spring design method according to claim 6, characterized in that: According to F1', d, and D, substitute each pair of values of h and t in the preliminary combination of h values and t values into the disc spring load calculator, select the values of h and t that satisfy the condition of 0 < K < 1, and form a useful combination of h values and t values.

8. The disc spring design method according to claim 7, characterized in that: Among the useful combinations of h values and t values, select the values of h and t that satisfy the stress preset condition, and form an effective combination of h values and t values. According to the effective combination of h values and t values, obtain multiple load curves. According to the multiple load curves, screen out those that satisfy 0 < K2 < K1 in the interval of F1' to F2', so as to obtain the final combination of h values and t values.

9. The disc spring design method according to claim 8, characterized in that: From the combinations of h values and t values that do not satisfy the stress preset condition, select some combinations of h values and t values. By adjusting the values of h and t, calculate the adjusted values of h and t, and select the values of h and t that satisfy the stress preset condition, h + t ≤ L, b > 1, 0 < K < 1, and 0 < K2 < K1, and add the selected values of h and t to the final combination of h values and t values; And / or, from the combinations of h values and t values that do not meet the stress preset condition, by adjusting the b value, select the h values and t values that meet the stress preset condition, h + t ≤ L, b > 1, 0 < K < 1, and 0 < K2 < K1, and add the selected h values and t values to the final combination of h values and t values.

10. The disc spring design method according to claim 8, characterized in that: Manufacture a prototype disc spring according to the final combination of h and t values, conduct a fatigue test on the prototype disc spring, and screen out the prototype disc springs that meet the reciprocating compression with the test range from (h - KX) to h and require a fatigue test life ≥ G million times, where G > 1.

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