Torque limiter for wind turbines

Abstract

The present application relates to a kind of torque limiters for wind-driven generators.The technical problems of existing torque limiters for wind-driven generators are solved, such as easy eccentric wear of friction plate, short service life, and difficulty in assembly and disassembly.The technical solution adopted by the present application is as follows: the torque limiter includes a double-tapered expansion sleeve, an adjusting assembly, a first friction disc, a second friction disc, a friction disc housing, a slip torque adjusting bolt, a brake disc, a diaphragm group, and a coupling flange.The double-tapered expansion sleeve is coupled with a transmission main shaft, the friction disc housing is sleeved on the double-tapered expansion sleeve, and the first and second friction discs are symmetrically mounted on both sides of the friction disc housing.The adjusting assembly is mounted in the adjusting hole provided in the first friction disc, the slip torque adjusting bolt couples the first and second friction discs and the double-tapered inner sleeve together, the brake disc is coupled with one end of the friction disc housing, the other end of the friction disc housing is coupled with the coupling flange, and the diaphragm group is arranged between the friction disc housing and the coupling flange.

Description

Technical Field

[0001] This invention belongs to the technical field of mechanical transmission overload protection devices, specifically relating to a torque limiter for wind turbine generators. Background Technology

[0002] In wind turbines, torque limiters are commonly used between the gearbox and the generator. They transmit torque and provide overload protection, making them one of the most critical transmission components. Their performance directly impacts the turbine's power generation efficiency. Currently, wind power is expanding into complex environments such as offshore, leading to increasingly higher maintenance costs for its main transmission systems. Therefore, designing a torque limiter that is simple in structure, has high torque regulation accuracy, is wear-resistant, highly reliable, has a long service life, and is easy to assemble and disassemble is crucial for better protecting the wind turbine's transmission system. However, most torque limiters for wind power currently use disc springs for pressure setting, which are prone to uneven wear of the friction plates, resulting in relatively low adjustment accuracy. The friction plates commonly used in torque limiters are copper-based or iron-based. When overload slippage occurs, the friction plate surface wears down, reducing the slippage torque. After repeated slippage, the limiter eventually fails completely, severely reducing its service life. Generally, the torque limiter for wind turbines is flush with the inner and outer mating surfaces of the drive shaft. When a large preload is applied to the expansion sleeve, the strong interference can cause the main shaft to break, increasing the difficulty of maintenance and disassembly. In severe cases, it may be necessary to cut off the drive shaft that it is mating with. Summary of the Invention

[0003] The purpose of this invention is to solve the technical problems of existing torque limiters for wind power, such as easy wear of friction plates, low adjustment accuracy, short service life, and difficulty in assembly and disassembly, and to provide a torque limiter for wind turbine generators.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A torque limiter for a wind turbine includes a double-cone expansion sleeve, an adjusting assembly, a first friction disc, a second friction disc, a friction disc housing, a slippage torque adjusting bolt, a brake disc, a diaphragm assembly, and a connecting flange. The double-cone expansion sleeve is connected to a drive shaft. The friction disc housing is fitted onto the double-cone expansion sleeve. The first and second friction discs are symmetrically mounted on opposite sides of the friction disc housing and located between the double-cone expansion sleeve and the friction disc housing. The adjusting assembly is installed in an adjusting hole in the first friction disc. The threaded end of the slippage torque adjusting bolt passes through the adjusting assembly and a pin hole in the double-cone inner sleeve of the double-cone expansion sleeve and connects to the second friction disc, connecting the first friction disc, the double-cone inner sleeve, and the second friction disc together. The brake disc is connected to one end of the friction disc housing via a first connecting bolt, and the other end of the friction disc housing is connected to the connecting flange via a second connecting bolt. The diaphragm assembly is located between the other end of the friction disc housing and the connecting flange.

[0006] Furthermore, the first friction disc is composed of a first friction disc body, a first screw, a first circular friction plate, and a first annular friction plate. The first friction disc body is a circular annular stepped columnar body. The first friction disc body is provided with an axial cylindrical pin hole. An adjustment hole is provided on the large end face of the first friction disc body, and the adjustment hole communicates with the axial cylindrical pin hole. The first circular friction plate is fixed to the end face of the large step of the first friction disc body by the first screw, and the first annular friction plate is adhered to the outer side of the small step of the first friction disc body.

[0007] The second friction disc is composed of a second friction disc body, a second screw, a second circular friction plate, and a second annular friction plate. The second friction disc body is a circular stepped columnar body with an axial threaded hole. The second circular friction plate is fixed to the end face of the large step of the second friction disc body by the second screw, and the second annular friction plate is attached to the outer side of the small step of the second friction disc body.

[0008] Furthermore, the first and second annular friction plates are equally divided into n segments, where n is 4 to 12.

[0009] Furthermore, a boss is provided in the middle of the inner surface of the friction disc housing, and annular friction plates of the housing are symmetrically provided on both sides of the boss.

[0010] Furthermore, the first and second annular friction plates, the first and second ring friction plates, and the housing annular friction plate are made of an alloy material with self-healing and self-repairing properties.

[0011] Furthermore, the adjustment assembly consists of a trapezoidal spring pad, a baffle, a cylindrical spring, and a hollow elastic cylindrical pin. The hollow elastic cylindrical pin is installed in the axial cylindrical pin hole provided in the first friction disc body, and one end of it is inserted into the pin hole provided in the double conical inner sleeve. The cylindrical spring, the baffle, and the trapezoidal spring pad are sequentially installed in the adjustment hole provided in the first friction disc body.

[0012] Furthermore, the double-cone expansion sleeve is composed of a double-cone inner sleeve, two locking rings, and an internal hexagon bolt; the thicknesses h1 and h2 of the left and right conical end faces of the double-cone inner sleeve are different, with a difference of 0 to 2.5 mm; the inner surface of the double-cone inner sleeve that contacts the transmission main shaft is micro-stepped, and the radii D1 and D2 of the inner surfaces of the left and right conical ends differ by 0 to 3.0 mm.

[0013] The beneficial effects of this invention are:

[0014] The torque transmission system of the present invention mainly includes a first friction disc, a second friction disc, a friction disc housing and an adjustment component. The friction disc material is made of an alloy material with self-healing and self-repairing properties (taking Babbitt alloy as an example). When the torque limiter slips, the Babbitt alloy begins to soften when the friction disc temperature rises to a certain value. After slippage stops, the friction plates, in a sealed environment, gradually cool and return to their original structure. The wear on the friction plates before and after slippage is low, and the friction coefficient of the friction pair is relatively stable. Compared to traditional copper-based and iron-based friction materials, which, after repeated slippage, experience severe wear leading to a decrease in contact pressure and a sharp drop in slippage torque, ultimately losing their torque limiting function, this invention provides more overload protection cycles, more stable torque, and a longer service life. The adjustment component consists of a trapezoidal spring pad, a baffle, a cylindrical spring, and a hollow elastic cylindrical pin. Adjusting the torque limiter via the slippage torque adjustment bolt to reach the predetermined slippage torque achieves bolt self-locking, stabilizing the Z-shaped friction plate sealing cavity composed of the first friction disc, the second friction disc, the friction disc housing, and the O-ring. This prevents the slippage torque adjustment bolt from loosening due to equipment vibration, which could lead to insufficient contact pressure of the friction pair and sealing cavity failure, thus improving torque adjustment accuracy. Furthermore, compared to the friction plate uneven wear caused by the traditional disc spring and bolt combination, this invention provides more uniform force on the friction plates, almost eliminating uneven wear.

[0015] Compared to traditional structures, the double-cone shrink sleeve of this invention has a slightly smaller thickness on the left conical end face than on the right, and the inner surface of the double-cone inner sleeve in contact with the shaft is slightly stepped. This design not only achieves the function of transmitting spindle torque, but also reduces the stress concentration caused by interference fit under bolt preload, which could damage the spindle and increase disassembly difficulty. Furthermore, this invention includes a diaphragm assembly between the friction disc housing and the connecting flange, providing a certain degree of misalignment compensation capability for the transmission system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention;

[0017] Figure 2 This is a schematic diagram of the friction disc of the present invention;

[0018] Figure 3 This is an enlarged view of the contact between the inner surface of the double-cone expansion sleeve of the present invention and the main shaft;

[0019] Figure 4 This is a simplified diagram of the wind turbine transmission system to which this invention applies;

[0020] In the diagram: 1-Transmission main shaft; 2-Double cone expansion sleeve; 21-Double cone inner sleeve; 22-Locking ring; 23-Hex socket head cap screw; 3-Adjusting assembly; 31-Trapezoidal spring pad; 32-Baffle; 33-Cylindrical spring; 34-Hollow elastic cylindrical pin; 4-First friction disc; 41-First friction disc body; 42-First screw; 43-First circular friction plate; 44-First annular friction plate; 5-Second friction disc; 51-Second friction disc body; 52-Second screw; 53-Second circular friction plate; 54-Second annular friction plate; 6-Friction disc housing; 61-Housing annular friction plate; 7-O-ring; 8-Slippage torque adjusting bolt; 9-Friction plate sealing cavity; 10-First connecting bolt; 11-Brake disc; 12-Diaphragm assembly; 13-Second connecting bolt; 14-Connecting flange; 15-Motor shaft; 16-Gearbox; 17-Torque limiter; 18-Generator. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] like Figures 1-2 As shown, a torque limiter for a wind turbine generator in this embodiment includes a double-cone expansion sleeve 2, an adjusting assembly 3, a first friction disc 4, a second friction disc 5, a friction disc housing 6, a slippage torque adjusting bolt 8, a brake disc 11, a diaphragm assembly 12, and a connecting flange 14. The double-cone expansion sleeve 2 is connected to the transmission main shaft 1. The friction disc housing 6 is fitted onto the double-cone expansion sleeve 2. The first friction disc 4 and the second friction disc 5 are symmetrically mounted on both sides inside the friction disc housing 6 and located between the double-cone expansion sleeve 2 and the friction disc housing 6. The adjusting assembly 3 is mounted on... In the adjustment hole provided in the first friction disc 4, the threaded end of the slippage torque adjusting bolt 8 passes through the pin hole provided in the adjusting assembly 3 and the double-cone inner sleeve 21 of the double-cone expansion sleeve 2, and connects to the second friction disc 5, thus connecting the first friction disc 4, the double-cone inner sleeve 21, and the second friction disc 5 together. The brake disc 11 is connected to one end of the friction disc housing 6 by the first connecting bolt 10, and the other end of the friction disc housing 6 is connected to the connecting flange 14 by the second connecting bolt 13. The diaphragm assembly 12 is located between the other end of the friction disc housing 6 and the connecting flange 14. The connecting flange 14 is connected to the motor shaft 15.

[0023] like Figures 1-2As shown, the first friction disc 4 is composed of a first friction disc body 41, a first screw 42, a first circular friction plate 43, and a first annular friction plate 44. The first friction disc body 41 is a circular stepped columnar body with an axial cylindrical pin hole. An adjustment hole is provided on the large end face of the first friction disc body 41, and the adjustment hole communicates with the axial cylindrical pin hole. The first circular friction plate 43 is fixed to the end face of the large step of the first friction disc body 41 by the first screw 42, and the first annular friction plate 44 is bonded to the outer side of the small step of the first friction disc body 41 with a high-temperature resistant adhesive.

[0024] The second friction disc 5 is composed of a second friction disc body 51, a second screw 52, ​​a second annular friction plate 53, and a second ring-shaped friction plate 54. The second friction disc body 51 is an annular stepped columnar body with an axial threaded hole. The second annular friction plate 53 is fixed to the end face of the large step of the second friction disc body 51 by the second screw 52, ​​and the second ring-shaped friction plate 54 is adhered to the outer surface of the small step of the second friction disc body 51 by adhesive. The first and second annular friction plates are equally divided into four segments.

[0025] A boss is provided in the middle of the inner surface of the friction disc housing 6, and annular friction plates 61 are symmetrically provided on the left and right sides of the boss. The annular friction plates 61 are bonded to the inner surface of the friction disc housing 6 with a high-temperature resistant adhesive.

[0026] The first and second annular friction plates 43 and 53, the first and second annular friction plates 44 and 54, and the housing annular friction plate 61 are made of Babbitt alloy material with self-healing and self-repairing properties. The friction plate material softens when heated and can restore its original structure in the sealed cavity 9 after cooling. The wear of the friction plates is low before and after slippage, and the friction coefficient of the friction pair is relatively stable.

[0027] The adjustment assembly consists of a trapezoidal spring pad 31, a baffle 32, a cylindrical spring 33, and a hollow elastic cylindrical pin 34. The hollow elastic cylindrical pin 34 is installed in the axial cylindrical pin hole of the first friction disc body 41, and one end of it is inserted into the pin hole of the double conical inner sleeve 21. The cylindrical spring 33, the baffle 32, and the trapezoidal spring pad 31 are sequentially installed in the adjustment hole of the first friction disc body 41.

[0028] The double-cone expansion sleeve 2 consists of a double-cone inner sleeve 21, two locking rings 22, and a hexagon socket head cap screw 23. The thicknesses h1 and h2 of the left and right conical end faces of the double-cone inner sleeve 21 are different, differing by 2.1 mm. The inner surface of the double-cone inner sleeve 21 that contacts the transmission spindle 1 is slightly stepped, with the radii D1 and D2 of the left and right conical end inner surfaces differing by 2.5 mm. A boss is provided in the middle of the outer surface of the double-cone inner sleeve 21, and a pin hole is provided on the boss. This double-cone expansion sleeve 2 not only meets the torque requirements of the transmission spindle 1 but also reduces the stress concentration caused by the interference fit under the preload of the hexagon socket head cap screw 23, thus reducing the difficulty of disassembly. It is worth noting that the end face corresponding to the smaller conical end face thickness h1 (larger inner surface radius D1) of the double-cone inner sleeve 21 is the end where the hexagon socket head cap screw 23 is threaded, and is not limited to this end face. Figure 3 As shown.

[0029] The present invention also includes an O-ring 7, which is installed in a sealing groove provided on the inner surface and the central boss of the friction disc housing 6, so that the first friction disc 4, the second friction disc 5, the friction disc housing 6 and the O-ring 7 form a Z-shaped friction plate sealing cavity 9. While ensuring that the overall structure does not change after the friction plate material softens due to heat, it can also prevent the friction coefficient of the friction pair contact surface from decreasing due to the entry of moisture, dust and other impurities in the air into the sealing cavity 9, which would lead to inaccurate slippage torque setting.

[0030] In the above embodiments, the first and second annular friction plates 43 and 53 can be equally divided into n segments, where n is 4 to 12; the first and second annular friction plates 43 and 53, the first and second annular friction plates 44 and 54, and the shell annular friction plate 61 can also be made of other alloy materials with self-healing and self-repairing functions; the difference between the thickness h1 and h2 of the left and right conical end faces of the double conical inner sleeve 21 in the double conical expansion sleeve 2 can be arbitrarily selected between 0 and 2.5 mm according to the structural dimensions of the torque limiter; the difference between the inner surface radii D1 and D2 of the left and right conical ends of the double conical inner sleeve 21 can also be arbitrarily selected between 0 and 3.0 mm according to the structural dimensions of the torque limiter.

[0031] The working process of this invention is as follows:

[0032] like Figure 1 , 4As shown, when the generator 18 is working normally, the frictional torque generated by the first friction disc 4, the second friction disc 5 and the friction disc housing 6 is greater than the working torque. The torque of the transmission main shaft 1 is transmitted to the generator 18 through the double cone expansion sleeve 2, the first friction disc 4, the second friction disc 5, the friction disc housing 6 and the connecting flange 14, thereby realizing the torque transmission function of the torque limiter 17 during normal operation. When the brake disc 11 is working, the generator 18 suddenly short-circuits or other electrical faults occur, slippage occurs between the first friction disc 4, the second friction disc 5 and the friction disc housing 6, cutting off the transmission between the gearbox 16 and the generator 18, thereby realizing the torque limiting function during overload and protecting the safety of the main drive chain.

Claims

1. A torque limiter for a wind turbine, characterized by: The utility model relates to a brake disc and belongs to the brake disc technical field, and it comprises a double-tapered expansion sleeve, an adjusting assembly, a first friction disc, a second friction disc, a friction disc shell, a slipping torque adjusting bolt, a brake disc, a diaphragm group and a coupling flange, wherein the double-tapered expansion sleeve is connected with a transmission main shaft, the friction disc shell is sleeved on the double-tapered expansion sleeve, the first friction disc and the second friction disc are symmetrically arranged in the two sides of the friction disc shell and located between the double-tapered expansion sleeve and the friction disc shell, the adjusting assembly is arranged in the adjusting hole of the first friction disc, the threaded end of the slipping torque adjusting bolt is connected with the second friction disc through the pin hole of the adjusting assembly and the double-tapered inner sleeve of the double-tapered expansion sleeve, and the first friction disc, the double-tapered inner sleeve and the second friction disc are connected together, the brake disc is connected with one end of the friction disc shell through the first connecting bolt, the other end of the friction disc shell is connected with the coupling flange through the second connecting bolt, and the diaphragm group is arranged between the other end of the friction disc shell and the coupling flange. The first friction disc is composed of a first friction disc body, a first screw, a first circular ring friction sheet and a first annular friction sheet, the first friction disc body is a circular ring stepped columnar body, the first friction disc body is provided with an axial cylindrical pin hole, the first friction disc body is provided with an adjusting hole on the large end face, and the adjusting hole is communicated with the axial cylindrical pin hole; the first circular ring friction sheet is fixed on the end face of the large step of the first friction disc body through the first screw, and the first annular friction sheet is adhered to the outer side face of the small step of the first friction disc body. The second friction disc is composed of a second friction disc body, a second screw, a second circular ring friction sheet and a second annular friction sheet, the second friction disc body is a circular ring stepped columnar body, the second friction disc body is provided with an axial threaded hole, the second circular ring friction sheet is fixed on the end face of the large step of the second friction disc body through the second screw, and the second annular friction sheet is adhered to the outer side face of the small step of the second friction disc body. The middle part of the inner surface of the friction disc shell is provided with a boss, and the boss is symmetrically provided with a shell annular friction sheet on the left and right sides. The adjusting assembly is composed of a trapezoidal elastic pad, a baffle, a cylindrical spring and a hollow elastic cylindrical pin, the hollow elastic cylindrical pin is arranged in the axial cylindrical pin hole of the first friction disc body, one end of the hollow elastic cylindrical pin is inserted into the pin hole of the double-tapered inner sleeve, and the cylindrical spring, the baffle and the trapezoidal elastic pad are sequentially arranged in the adjusting hole of the first friction disc body. The first and second circular ring friction sheets, the first and second annular friction sheets and the shell annular friction sheet are made of alloy materials with self-healing and self-repairing functions, and the first friction disc, the second friction disc, the friction disc shell and the O-shaped ring form a Z-shaped friction sheet sealing cavity.

2. A torque limiter for a wind turbine according to claim 1, characterised in that: The first and second circular ring friction plates are each divided into n segments, n 4-12.

3. A torque limiter for a wind turbine according to claim 1, characterized in that: The double-tapered expansion sleeve is composed of a double-tapered inner sleeve, two locking rings and an inner hexagonal bolt h 1、 h 2The thicknesses of the left and right tapered end faces of the double-tapered inner sleeve are different, with a difference of 0-2.5mm D 1The inner surface of the double-tapered inner sleeve in contact with the transmission main shaft is in a micro-step shape, and the radii of the left and right tapered end inner surfaces are different D 2The difference is 0-3.0mm.

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