A combined torque limiter and a wind turbine coupling having the same.

Abstract

This invention relates to a combined torque limiter and a wind turbine coupling having the same, in the field of wind turbine coupling technology. The torque limiter includes a torque limiter flange, at least two pressure plates, at least two friction plates, and multiple friction pads. The pressure plates are connected to the torque limiter flange via the same set of bolts. The friction plates are respectively disposed between the torque limiter flange and adjacent pressure plates, and between adjacent pressure plates. The friction pads are disposed between the flange and the friction plates, and between the pressure plates and the friction plates, forming multiple friction pairs connected in series. Adjacent friction plates are connected by end face splines to transmit torque and provide axial adjustment clearance. The bolts ensure that all friction pairs generate equal positive pressure. This invention uses the same set of bolts to uniformly tighten all friction pairs, ensuring equal force on each friction pad and eliminating pressure superposition. Within the bearing capacity limit of the friction pads, it effectively increases the slippage torque. Furthermore, it has a compact structure, is easy to debug, and operates stably and reliably, making it suitable for high-power wind turbine couplings.

Description

Technical Field

[0001] This invention relates to the field of wind turbine coupling technology, and more particularly to a combined torque limiter and a wind turbine coupling having the same. Background Technology

[0002] In wind turbine generator sets, the torque limiter built into the wind turbine coupling is a critical overload protection device. When the system torque increases abnormally, the torque limiter relieves the overload torque through the relative sliding of the friction pair, preventing the gearbox from failing due to excessive load. As wind turbine generator sets develop towards higher power, higher requirements are placed on the torque transmission capacity and space adaptability of the coupling: it is necessary to improve the slippage torque to meet the protection requirements of high-power units, and at the same time control the radial dimensions of the coupling to adapt to the limited nacelle space.

[0003] To address the aforementioned contradictions, a series torque limiter wind turbine coupling (patent number: CN219673136U) is disclosed in the prior art. This technology employs a multi-friction pair series structure, mainly comprising a fiberglass cylinder, flange, friction flange, pressure plate, and friction disc. Its core structure involves setting stepped rings on the flange and pressure plate to form an annular channel to accommodate the left side disc of the friction flange. Multiple sets of friction plates are placed between the stepped surface and the friction flange, and between the pressure plate and the friction disc, achieving a series arrangement of multiple friction pairs. This technology controls the slippage torque through two independent adjustment mechanisms (the first set uses friction plates C and A between the friction flange and the flange / pressure plate, adjusting the slippage torque of this set of friction pairs via adjusting bolt B; the second set uses friction plate B between the friction disc and the pressure plate, adjusting the slippage torque of this set of friction pairs via adjusting bolt A). When the transmitted torque is less than the sum of the friction torques of each friction pair, the coupling does not slip; when the transmitted torque exceeds a threshold, the friction pairs slide relative to each other, providing slippage protection. This technical solution improves the slippage torque without significantly increasing the radial dimension of the coupling by connecting multiple friction pairs in series, providing an important solution for the miniaturization and high torque of wind power couplings.

[0004] However, in subsequent research and practical applications, the applicant further discovered that although the aforementioned series torque limiter can theoretically increase slippage torque, it has a structural technical problem in practical engineering applications:

[0005] 1. The phased tightening of the two bolts causes the intermediate friction plate to bear superimposed pressure, which can easily exceed the bearing capacity of the friction material. The tightening process and stress state of this technology are as follows:

[0006] 1.1 First, tighten the inner ring bolt (adjusting bolt A) to generate pressure F1. At this time, pressure F1 acts on friction plate B and friction plate C, and the pressure on friction plate A is 0.

[0007] 1.2 After tightening the inner ring bolt, tighten the outer ring bolt (adjusting bolt B) to generate pressure F2. At this time, the pressure on friction plate B remains unchanged at F1, and the pressure on friction plate C increases to F2, making the total pressure on friction plate C F1+F2, and the pressure on friction plate A F2.

[0008] According to the friction formula Fm=F×μ (Fm is the friction force, F is the pressure, and μ is the coefficient of friction), the total friction force is theoretically Fm=F1×μ×2+F2×μ×2, and the torque increase is as expected.

[0009] However, friction materials possess a crucial physical characteristic—the pressure limit. When the pressure exceeds the friction plate's bearing capacity, the friction material will crush and fail, causing system instability and ultimately leading to the complete failure of the torque limiter. In ordinary torque limiters, the working pressure of the friction plate is already close to its pressure limit. In the aforementioned structure, friction plate C simultaneously bears the combined pressures of F1 and F2. When F1 and F2 reach their respective normal working pressures, the total pressure F1 + F2 on friction plate C may exceed its pressure limit. To protect friction plate C from crushing, the sum of F1 + F2 must be limited, meaning that both F1 and F2 must be below their normal working pressures. This severely restricts the overall frictional force increase of the torque limiter, failing to achieve the expected multiplication effect. In other words, the theoretical calculations of this technology neglect this critical engineering constraint of the friction material's pressure limit, resulting in an actual feasible slippage torque far lower than the theoretical value.

[0010] 2. The phased adjustment mechanism of the two bolt rings complicates the debugging process, and the pressures affect each other. Because both bolt rings need to be tightened in two stages, operators must repeatedly adjust them to achieve the designed pressure value, resulting in low assembly efficiency. More seriously, the clamping forces generated by the two bolt rings influence each other—adjusting the outer bolt ring changes the pressure state of the intermediate friction plate, thus affecting the balance already established by the inner bolt ring. This coupled pressure adjustment mechanism makes precise control of the pressure of each friction pair extremely difficult.

[0011] 3. High risk of pressure imbalance during long-term operation. Even if properly adjusted during assembly, the preload decay rate of the two bolts is difficult to guarantee synchronously during long-term operation. In addition, the different wear levels of the friction plates will gradually cause the pressure of each friction pair to become unbalanced, further exacerbating the pressure risk of friction plate C and seriously affecting the long-term reliability of the torque limiter.

[0012] Therefore, how to provide a wind turbine coupling that can effectively increase the slippage torque within the bearing limit of the friction plates, while simplifying the debugging process and ensuring long-term stable operation, has become a pressing technical problem to be solved in this field. Specifically, a new structural solution is needed that ensures equal force on each friction plate and eliminates pressure superposition. Under the premise that each friction plate operates within its bearing limit, the total friction force can be effectively increased by reasonably increasing the number of friction pairs. Summary of the Invention

[0013] To overcome the shortcomings of the prior art, the present invention discloses a combined torque limiter and a wind power coupling having the same.

[0014] To achieve the above objectives, the present invention adopts the following technical solution:

[0015] A combined torque limiter includes:

[0016] Torque limiter flange;

[0017] At least two pressure plates are connected to the torque limiter flange via the same set of bolts;

[0018] At least two friction discs are respectively disposed between the torque limiter flange and the adjacent pressure disc, and between two adjacent pressure discs;

[0019] Multiple friction plates are respectively arranged between the torque limiter flange and its adjacent friction disc, and between each pressure plate and its adjacent friction disc, forming multiple friction pairs in series;

[0020] The two adjacent friction discs are connected by end face splines, which are used to transmit torque and provide axial adjustment clearance.

[0021] The bolts are used to generate a predetermined positive pressure on all friction pairs.

[0022] Furthermore, the tooth profile of the end face spline is straight, and the working surfaces on both sides of the tooth are radial planes passing through its axis.

[0023] Furthermore, an elastic washer is fitted onto the bolt, which is used to compensate for the axial clearance caused by wear of the friction pair.

[0024] Furthermore, the torque limiter flange is positioned with respect to the adjacent pressure plate and between two adjacent pressure plates by elastic cylindrical pins, and a gap is provided between two adjacent elastic cylindrical pins along the axial direction.

[0025] Furthermore, the bolts pass through the central holes of each of the elastic cylindrical pins to connect each pressure plate to the torque limiter flange as a whole.

[0026] Furthermore, a sealing ring is fitted on the outer circle of the end face spline, and the two ends of the sealing ring are sealed with sealant.

[0027] Furthermore, there are multiple bolts, which are evenly distributed along the circumference of the pressure plate and the torque limiter flange.

[0028] Furthermore, the friction plates are mounted on the torque limiter flange and the pressure plate respectively using countersunk screws.

[0029] The present invention also provides a wind power coupling, including the above-mentioned combined torque limiter, and further including a coupling flange and a fiberglass tube, wherein the coupling flange and the fiberglass tube are fixedly connected to the torque limiter flange of the combined torque limiter.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] 1. This invention uses the same set of bolts to simultaneously tighten all friction pairs, ensuring that each friction pair bears equal normal pressure. This completely avoids the problem of pressure superposition on intermediate friction plates caused by the partial tightening of two rings of bolts in existing technologies. Each friction plate operates within its bearing capacity limit, eliminating the risk of local overload. Thus, under the same friction plate size and bolt tightening torque, increasing the number of friction pairs can multiply the slippage torque.

[0032] 2. Adjacent friction discs are connected by end-face splines with straight tooth profiles and radial planes on both sides of each tooth passing through the axis. This structure can transmit torque while allowing for minute relative displacement between the friction discs along the axial direction, thus achieving axial adaptive adjustment when the clamping force changes and automatically balancing the normal pressure of each friction pair. Even with manufacturing tolerances or assembly errors, the axial floating capability of the end-face splines ensures uniform pressure distribution across the friction pairs, avoiding localized overload and uneven wear.

[0033] 3. The elastic washers fitted on the bolts can automatically extend to compensate for the axial clearance when the friction plates wear due to long-term use, keeping the bolt preload essentially constant. This mechanism ensures that the normal pressure of each friction pair does not decrease with the wear of the friction plates, and the slippage torque remains stable and reliable over a long period, significantly extending the maintenance cycle and service life of the torque limiter.

[0034] 4. The pressure setting of all friction pairs can be completed by tightening the same set of bolts only once, eliminating the need for two tightenings and repeated adjustments as required by existing technologies. This not only significantly improves assembly efficiency but also avoids the debugging difficulties caused by the mutual coupling of pressure from multiple sets of bolts, making the pressure control of the torque limiter more precise and reliable.

[0035] 5. Each elastic cylindrical pin radially positions the adjacent pressure plates and the pressure plate and torque limiter flange, and a gap is provided between two adjacent elastic cylindrical pins along the axial direction. This structure ensures accurate alignment between each pressure plate and the flange, while allowing slight axial movement, avoiding poor pressure transmission or jamming due to over-positioning, and ensuring smooth transmission of clamping force to each friction pair.

[0036] 6. The sealing ring sleeved on the outer circle of the spline end face and the sealant coated at both ends can effectively prevent external dust and moisture from entering the spline and friction pair area, avoid changes in the friction coefficient or corrosion of components due to environmental factors, and ensure that the torque limiter can work stably and reliably under various harsh working conditions. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the combined torque limiter in this invention;

[0038] Figure 2 for Figure 1 Enlarged view of part I in the image;

[0039] Figure 3 This is a schematic diagram of the mating structure of two adjacent friction discs in this invention;

[0040] Figure 4 This is a front view of the friction disk in this invention;

[0041] Figure 5 This is a schematic diagram of the wind turbine coupling in this invention;

[0042] Figure 6 This is a schematic diagram of a common torque limiter.

[0043] In the diagram: 1. Torque limiter flange; 2. Pressure plate; 21. First pressure plate; 22. Second pressure plate; 3. Bolt; 4. Friction disc; 41. First friction disc; 42. Second friction disc; 5. Friction pad; 51. First friction pad; 52. Second friction pad; 53. Third friction pad; 54. Fourth friction pad; 6. Elastic gasket; 7. Elastic cylindrical pin; 71. First elastic cylindrical pin; 72. Second elastic cylindrical pin; 8. Sealing ring; 9. Countersunk screw; 10. Coupling flange; 11. Fiberglass tube. Detailed Implementation

[0044] The present invention will be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. In the description of the present invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," etc., indicating orientation or positional relationships, are only corresponding to the drawings of this application for the convenience of describing the present invention. The terms "end," "side," "end portion," "side part," "lateral," "longitudinal," etc., indicating orientation or positional relationships, are only corresponding to the length and width of the corresponding components. That is, "end portion" indicates the beginning and end areas in the length direction of the corresponding component, and "side part" indicates the beginning and end areas in the width direction of the corresponding component. The term "provided with" should be understood in the art as "provided with" or "assembled with," and does not limit the specific connection method. The term "corresponding" should be understood in the art as being used to describe the relative positional relationship, functional cooperation relationship, or spatial alignment relationship between two components. For the convenience of describing the present invention, it is not intended to indicate or imply that the device or element referred to must have a specific orientation.

[0045] Please refer to the instruction manual appendix. Figure 1-5 The present invention provides the following technical solutions:

[0046] Please see Figures 1 to 5 The present invention provides a combined torque limiter, including a torque limiter flange 1, at least two pressure plates 2, at least two friction plates 4, and a plurality of friction plates 5.

[0047] The torque limiter flange 1 has a disc-shaped structure. One side of the torque limiter flange 1 (e.g.) Figure 1 The right side of the middle section has a mounting surface for mounting the friction plate 5.

[0048] There are at least two pressure plates 2, both of which are disc-shaped and arranged parallel to each other along the axial direction. The pressure plate 2 closest to the torque limiter flange 1 (hereinafter referred to as the "first pressure plate") is adjacent to the torque limiter flange 1, and the remaining pressure plates 2 are arranged in sequence. Each pressure plate 2 has mounting surfaces on both sides for mounting friction plates 5.

[0049] All pressure plates 2 are fixedly connected to the torque limiter flange 1 by the same set of bolts 3. Specifically, there are multiple bolts 3 (e.g., 14, 16, or 18), evenly distributed along the circumference, passing through the through holes on each pressure plate 2 and engaging with the threaded holes on the torque limiter flange 1 (or being tightened with nuts after passing through the torque limiter flange 1). By tightening the bolts 3, an axial clamping force can be applied to all pressure plates 2, which is ultimately transmitted to each friction pair, giving all friction pairs a predetermined positive pressure.

[0050] There are at least two friction discs 4, each disposed between different adjacent components:

[0051] The first friction disc 4 is positioned between the torque limiter flange 1 and the adjacent pressure disc 2 (i.e., the first pressure disc);

[0052] The subsequent friction discs 4 are sequentially arranged between two adjacent pressure discs 2.

[0053] Each friction disc 4 is a ring-shaped structure with a central shaft hole. Both sides of the disc are friction working surfaces, which cooperate with the adjacent friction plates 5 to form a friction pair.

[0054] There are multiple friction plates 5, which are respectively disposed in the following positions:

[0055] Between the torque limiter flange 1 and the adjacent friction disc 4;

[0056] Each pressure plate 2 is connected to its adjacent friction plate 4 (i.e., each friction plate 4 has a corresponding friction pad 5 on each side).

[0057] This results in multiple friction pairs connected in series, with the number of friction pairs being twice the number of friction discs 4.

[0058] The end-face spline is disposed between two adjacent friction discs 4. Specifically, one side of one friction disc 4 has external spline teeth, and the corresponding side of the other friction disc 4 has internal spline teeth, which mesh with each other to form an end-face spline connection. Figure 3 , Figure 4 As shown, the tooth profile of the end face spline is straight, and the working surfaces on both sides of each tooth are radial planes passing through its axis (i.e., the rotation axis of the combined torque limiter). This structure allows the spline to transmit torque while also allowing small relative displacements along the axial direction between adjacent friction discs 4, thereby achieving axial adaptive adjustment when the clamping force changes, ensuring uniform pressure on each friction pair.

[0059] The elastic washer 6 is fitted onto the bolt 3, located between the bolt head and the outermost pressure plate 2 (or between the nut and the torque limiter flange 1, depending on the bolt's insertion direction). The elastic washer 6 is preferably a disc spring washer. When the friction plates wear down due to long-term use, causing an increase in axial clearance, the elastic deformation of the elastic washer 6 can automatically compensate for this clearance, thereby maintaining a basically constant bolt preload and ensuring long-term stability of the positive pressure of each friction pair, preventing the slippage torque from diminishing.

[0060] To ensure accurate alignment between each pressure plate 2 and the torque limiter flange 1, resilient cylindrical pins 7 are provided between the torque limiter flange 1 and its adjacent pressure plate 2, as well as between two adjacent pressure plates 2. Each resilient cylindrical pin 7 is axially positioned for radial positioning between adjacent components. A gap is provided between two axially adjacent resilient cylindrical pins 7 (see...). Figure 3This clearance allows for slight axial movement between the pressure plates 2 and between the pressure plates 2 and the torque limiter flange 1, preventing over-positioning due to manufacturing errors or thermal expansion, while ensuring smooth pressure transmission. Bolts 3 pass through the center holes of each elastic cylindrical pin 7, connecting all pressure plates 2 to the torque limiter flange 1 as a single unit.

[0061] To prevent external dust and moisture from entering the spline and friction pair areas and affecting performance, a sealing ring 8 is fitted on the outer circumference of the end face spline. The sealing ring 8 is an elastic rubber ring, with sealant applied to both ends for enhanced sealing. In addition, sealing rings (not marked) can also be installed between the torque limiter flange 1 and the adjacent pressure plate 2, and between each pressure plate 2, to improve overall sealing performance.

[0062] Working principle

[0063] When bolts 3 are tightened, the clamping force is transmitted sequentially through the outermost pressure plate 2, each friction pair, and each friction disc 4 to the torque limiter flange 1, forming a pressure closed loop. Since all friction pairs are clamped by the same set of bolts 3, and adjacent friction discs 4 are connected by end face splines and are allowed to float axially, the normal pressure borne by each friction pair is basically equal, which is the total preload generated by bolts 3 divided by the number of friction pairs. There is no pressure superposition phenomenon.

[0064] When the torque transmitted by the wind turbine coupling exceeds the set slippage torque, the friction pairs begin to slide relative to each other, generating frictional torque between the friction disc and the friction plates. Since the normal pressure of each friction pair is equal, the frictional torque contributed by each friction pair is also equal, and the total slippage torque is the sum of the frictional torques of all friction pairs. By rationally designing the number of friction pairs and the friction coefficient, the slippage torque can be effectively increased without increasing the pressure on the friction plates.

[0065] During long-term operation, friction plates inevitably wear, leading to an increase in the axial clearance of the friction pair. At this time, the elastic shim 6 automatically extends to compensate for the clearance, keeping the preload of the bolt 3 stable, thereby maintaining a constant positive pressure on each friction pair and preventing the slippage torque from decreasing. The axial self-adaptive capability of the end face spline also ensures that the pressure distribution remains uniform, preventing localized overload due to uneven wear.

[0066] Example 1, please refer to Figures 1 to 4 This embodiment provides a combined torque limiter, including a torque limiter flange 1, two pressure plates 2 (first pressure plate 21 and second pressure plate 22), two friction plates 4 (first friction plate 41 and second friction plate 42) and four friction plates 5 (first friction plate 51, second friction plate 52, third friction plate 53 and fourth friction plate 54).

[0067] The torque limiter flange 1 has a disc-shaped structure with a central shaft hole for connecting to other components of the wind turbine coupling. One side of the torque limiter flange 1 (e.g.) Figure 1 The right side of the middle section has a mounting surface for installing the first friction plate 51.

[0068] The first pressure plate 21 and the second pressure plate 22 are both disc-shaped and arranged in parallel at intervals. The first pressure plate 21 is located between the torque limiter flange 1 and the second pressure plate 22. The first pressure plate 21 has mounting surfaces on both sides for mounting the second friction plate 52 and the third friction plate 53, respectively; the second pressure plate 22 has a mounting surface on one side for mounting the fourth friction plate 54.

[0069] The first pressure plate 21 and the second pressure plate 22 are fixedly connected to the torque limiter flange 1 by the same set of bolts 3. Specifically, there are multiple bolts 3 (e.g., 14, 16, or 18), evenly distributed along the circumference, passing through the through holes on the second pressure plate 22 and the first pressure plate 21, and threadedly engaging with the threaded holes on the torque limiter flange 1. By tightening the bolts 3, an axial clamping force can be applied to the first pressure plate 21 and the second pressure plate 22, which is ultimately transmitted to each friction pair, giving each friction pair a predetermined positive pressure.

[0070] The first friction disc 41 is disposed between the torque limiter flange 1 and the first pressure plate 21. It is annular in shape and has a shaft hole in the center. Both sides of the first friction disc 41 are friction working surfaces, which mate with the first friction plate 51 and the second friction plate 52, respectively.

[0071] The second friction disc 42 is disposed between the first pressure disc 21 and the second pressure disc 22. It is also annular in shape and has a shaft hole in the center. Both sides of the second friction disc 42 are friction working surfaces, which cooperate with the third friction plate 53 and the fourth friction plate 54 respectively.

[0072] All four friction plates 5 are annular and made of wear-resistant friction material.

[0073] The first friction plate 51 is fixedly installed on one side (right side) of the torque limiter flange 1 by countersunk screws 9, and is in contact with the left side of the first friction disc 41 to form the first friction pair.

[0074] The second friction plate 52 is fixedly installed on one side (left side) of the first pressure plate 21 by countersunk screws 9, and is in contact with the right side of the first friction plate 41 to form a second friction pair.

[0075] The third friction plate 53 is fixedly installed on the other side (right side) of the first pressure plate 21 by countersunk screws 9, and is in contact with the left side of the second friction plate 42 to form a third friction pair.

[0076] The fourth friction plate 54 is fixedly installed on one side (left side) of the second pressure plate 22 by countersunk screws 9, and is in contact with the right side of the second friction plate 42 to form the fourth friction pair.

[0077] Since the friction plates 5 are all installed by countersunk screws 9, it can be ensured that the friction plates 5 are in close contact with the corresponding mounting surfaces and that the positioning is reliable.

[0078] An end-face spline is disposed between the first friction disk 41 and the second friction disk 42. Specifically, the right side of the first friction disk 41 has external spline teeth, and the left side of the second friction disk 42 has internal spline teeth, which mesh with each other to form an end-face spline connection. Figure 3 , Figure 4 As shown, the tooth profile of the end face spline is straight, and the working surfaces on both sides of each tooth are radial planes passing through its axis. This structure allows the spline to transmit torque while also allowing for small relative displacements along the axial direction between the first friction disc 41 and the second friction disc 42, thereby achieving axial adaptive adjustment when the clamping force changes and ensuring uniform pressure on each friction pair.

[0079] An elastic washer 6 is fitted between the head of the bolt 3 and the second pressure plate 22 (in this embodiment, the bolt 3 is inserted from one side of the second pressure plate 22). The elastic washer 6 is preferably a disc spring washer. When the friction plate wears due to long-term use, resulting in an increase in axial clearance, the elastic deformation of the elastic washer 6 can automatically compensate for the clearance, thereby maintaining the bolt preload basically constant, ensuring that the normal pressure of each friction pair is stable for a long time, and the slippage torque does not decrease.

[0080] To achieve accurate alignment between the pressure plates and the flanges, this embodiment includes a first elastic cylindrical pin 71 and a second elastic cylindrical pin 72. The first elastic cylindrical pin 71 is axially positioned between the torque limiter flange 1 and the first pressure plate 21 for radial positioning. The second elastic cylindrical pin 72 is axially positioned between the first pressure plate 21 and the second pressure plate 22 for radial positioning. The first elastic cylindrical pin 71 and the second elastic cylindrical pin 72 are spaced apart axially, with a pre-existing gap between them (see [reference]). Figure 2 This clearance allows for slight axial movement between the pressure plates and between the pressure plates and the flange, ensuring smooth pressure transmission. Bolt 3 passes through the center holes of the second elastic cylindrical pin 72 and the first elastic cylindrical pin 71, connecting the second pressure plate 22, the first pressure plate 21, and the torque limiter flange 1 as a whole.

[0081] To prevent external dust and moisture from entering the spline and friction pair areas and affecting performance, a sealing ring 8 is fitted on the outer circumference of the end face spline. The sealing ring 8 is an elastic rubber ring, with sealant applied to both ends for enhanced sealing. In addition, sealing rings (not marked) can also be installed between the torque limiter flange 1 and the first pressure plate 21, and between the first pressure plate 21 and the second pressure plate 22, to improve overall sealing performance.

[0082] Working principle: When bolt 3 is tightened, the clamping force is transmitted sequentially through the second pressure plate 22, the fourth friction pair (fourth friction plate 54 and second friction plate 42), the third friction pair (third friction plate 53 and second friction plate 42), the first pressure plate 21, the second friction pair (second friction plate 52 and first friction plate 41), and the first friction pair (first friction plate 51 and first friction plate 41) to the torque limiter flange 1, forming a pressure closed loop. Since all friction pairs are clamped by the same set of bolts 3, and the first friction plate 41 and the second friction plate 42 are connected by end face splines and are allowed to float axially, the normal pressure borne by each friction pair is basically equal, which is the total preload generated by bolt 3 divided by the number of friction pairs (4 in this case), and there is no pressure superposition phenomenon.

[0083] When the torque transmitted by the wind turbine coupling exceeds the set slippage torque, the friction pairs begin to slide relative to each other, generating frictional torque between the friction discs and friction plates. Since the normal pressure of each friction pair is equal, the frictional torque contributed by each friction pair is also equal, and the total slippage torque is the sum of the frictional torques of all friction pairs. By rationally designing the number of friction pairs and the friction coefficient, the slippage torque can be effectively increased without increasing the pressure on the friction plates, thus meeting the requirements of high-power wind turbine couplings.

[0084] During long-term operation, friction plates inevitably wear, leading to an increase in the axial clearance of the friction pair. At this time, the elastic shim 6 automatically extends to compensate for the clearance, keeping the preload of the bolt 3 stable, thereby maintaining a constant positive pressure on each friction pair and preventing the slippage torque from decreasing. The axial self-adaptive capability of the end face spline also ensures that the pressure distribution remains uniform, preventing localized overload due to uneven wear.

[0085] To verify the technical effect of the present invention, a conventional torque limiter was used as a control group, such as... Figure 6 As shown, the combined torque limiter described in Embodiment 1 was used as the test group, and a comparative test was conducted under the same conditions. In the test, both torque limiters used the same friction material, and the bolt tightening torque was set to 150 Nm. The slippage torque value was then tested. The test results are shown in Table 1.

[0086] Table 1 Comparison of experimental results between the experimental group and the control group

[0087]

[0088] Test results show that, under the same bolt tightening torque conditions, the combined torque limiter of this invention increases the slippage torque by approximately 96% compared to the existing series torque limiter, essentially achieving the expected significant improvement. This verifies that the structural design of this invention, through the unified tightening of the same set of bolts and equal pressure on each friction pair, effectively avoids the problem of pressure superposition, allowing each friction plate to operate near its bearing limit, thereby significantly improving the slippage torque under the same radial dimensions.

[0089] Example 2: A combined torque limiter differs from Example 1 in the installation method of bolt 3. Bolt 3 passes through the through holes on the second pressure plate 22, the first pressure plate 21, and the torque limiter flange 1 simultaneously, and is tightened by a nut. An elastic washer 6 is fitted onto bolt 3, located between the nut and the torque limiter flange 1.

[0090] Example 3, a combined torque limiter, differs from Example 1 in that: the elastic gasket 6 can be a combination of multiple spring gaskets, as long as it can achieve the wear compensation function. Furthermore, the material of the sealing ring 8 can be selected from oil-resistant, high-temperature-resistant rubber or polyurethane materials depending on the working environment.

[0091] Example 4: This example provides a wind turbine coupling that includes the aforementioned combined torque limiter. For example... Figure 5 As shown, the wind turbine coupling also includes a coupling flange 10 and a fiberglass cylinder 11. The coupling flange 10 is used to connect to the output shaft of the wind turbine generator gearbox. The fiberglass cylinder 11 is an insulating cylinder, with its two ends fixedly connected (e.g., by adhesive bonding) to the coupling flange 10 and the torque limiter flange 1, respectively. The other end of the wind turbine coupling (not shown) is connected to the generator input shaft. When an overload torque occurs between the gearbox and the generator, the combined torque limiter slips internally, protecting the gearbox from damage.

[0092] Structures, components, and connection methods not described in detail in this invention are all prior art known to those skilled in the art unless otherwise specified. It is obvious to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that the invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the invention. Therefore, the above embodiments should be regarded as exemplary and non-limiting in all respects. The scope of this invention is defined by the appended claims rather than the foregoing description, and therefore all changes falling within the meaning and scope of the equivalents of the claims are intended to be included within this invention.

Claims

1. A combined torque limiter, characterized in that, include: Torque limiter flange (1); At least two pressure plates (2) are connected to the torque limiter flange (1) by the same set of bolts (3); At least two friction discs (4) are respectively disposed between the torque limiter flange (1) and the adjacent pressure disc (2), and between two adjacent pressure discs (2); Multiple friction plates (5) are respectively disposed between the torque limiter flange (1) and its adjacent friction disc (4), and between each pressure plate (2) and its adjacent friction disc (4), forming a series friction pair. The number of the series friction pairs is twice the number of the friction discs (4). Among them, two adjacent friction discs (4) are connected by end face splines. The tooth profile of the end face splines is straight, and the working surfaces on both sides of the teeth are radial planes passing through their axis. The end face splines are used to transmit torque and provide axial adjustment clearance. The bolt (3) is used to generate a predetermined positive pressure on all friction pairs.

2. The combined torque limiter according to claim 1, characterized in that: An elastic washer (6) is fitted on the bolt (3), and the elastic washer (6) is used to compensate for the axial clearance caused by wear of the friction pair.

3. The combined torque limiter according to claim 1, characterized in that: The torque limiter flange (1) is positioned with respect to the adjacent pressure plate (2) and between two adjacent pressure plates (2) by elastic cylindrical pins (7), and there is a gap between two adjacent elastic cylindrical pins (7) along the axial direction.

4. The combined torque limiter according to claim 3, characterized in that: The bolts (3) pass through the center holes of each of the elastic cylindrical pins (7) to connect each pressure plate (2) to the torque limiter flange (1) as a whole.

5. The combined torque limiter according to claim 1, characterized in that: A sealing ring (8) is fitted on the outer circle of the end face spline, and the two ends of the sealing ring (8) are sealed with sealant.

6. The combined torque limiter according to claim 1, characterized in that: There are multiple bolts (3), which are evenly distributed along the circumference of the pressure plate (2) and the torque limiter flange (1).

7. The combined torque limiter according to claim 1, characterized in that: The friction plate (5) is installed on the torque limiter flange (1) and the pressure plate (2) respectively by countersunk screws (9).

8. A wind power coupling, characterized in that: The combined torque limiter as described in any one of claims 1 to 7 further includes a coupling flange (10) and a fiberglass tube (11), wherein the coupling flange (10) and the fiberglass tube (11) are fixedly connected to the torque limiter flange (1) of the combined torque limiter.

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