A wind turbine main shaft anti-loosening structure
Patent Information
- Application Number
- CN202522450634.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-19
- Publication Date
- 2026-08-21
- Estimated Expiration
- 2035-11-19
AI Technical Summary
[0003]然而，在风电机组严苛的运行环境下，胀紧套上的螺栓长期承受剧烈的振动和冲击载荷
[0014]本实用新型通过设置防脱件，利用一个螺栓上的螺母来固定防脱件，同时该防脱件的限位卡座又能限制相邻螺栓上的螺母。这种“连环”锁紧方式结构简单、安装方便。即使在强振动工况下，万一某个螺母有松动趋势，也会被限位卡座的限位板阻挡，无法沿轴向脱出，从而提高胀紧套连接的安全性，防止因螺母脱落导致的风机重大事故。
Smart Images
Figure CN224665086U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of wind power generation technology, specifically to a wind turbine main shaft anti-loosening structure. Background Technology
[0002] Wind turbines are among the mainstream clean energy devices today. They operate under harsh conditions, enduring alternating loads, strong vibrations, and enormous torques over extended periods. The main shaft (shaft body) of a wind turbine is responsible for transmitting the wind energy torque from the blade hub to the gearbox. The connection between the main shaft and the low-speed shaft of the gearbox is a crucial link in the entire transmission chain. The main shaft structure of direct-drive wind turbines varies significantly, with some using dual bearings and others single bearings. In a cantilever beam structure supported by a single bearing, the front end of the main shaft is supported by a main shaft bearing. The rear end of the main shaft connects to the gearbox, typically using a shrink-fit sleeve (also known as a "friction lock"). Tightening a ring of high-strength bolts on the shrink-fit sleeve causes radial deformation of the inner and outer rings, generating significant friction between the mating surfaces of the main shaft and the low-speed shaft of the gearbox to transmit torque and axial force.
[0003] However, in the harsh operating environment of wind turbines, the bolts on the expansion sleeve are subjected to severe vibration and impact loads over a long period. This can easily lead to the bolts loosening or even falling off. Once the bolts loosen, the clamping force of the expansion sleeve will decrease (the inner and outer rings will separate), causing relative slippage between the main shaft and the low-speed shaft of the gearbox. This can cause minor issues such as abnormal noise and wear, or even transmission failure and serious safety accidents such as blade runaway. In addition, the connection structure between the main shaft and the gearbox needs to have high reliability, precise axial positioning, good shock absorption and buffering capabilities, and overload protection under extreme operating conditions to protect the expensive gearbox and main shaft.
[0004] Therefore, how to provide a structure that can effectively prevent the expansion sleeve nut from loosening and falling off, while ensuring reliable spindle connection and providing shock absorption and overload protection functions, is a technical problem that urgently needs to be solved in this field. Utility Model Content
[0005] The purpose of this utility model is to overcome the defects in the above-mentioned background technology and provide a wind turbine main shaft anti-loosening structure. This structure is simple and can not only effectively prevent the nuts of the expansion sleeve bolts from loosening, but also improve the reliability, shock absorption and overload protection of the main shaft connection.
[0006] The technical solution adopted by this utility model to solve the above problems is: a wind turbine main shaft anti-loosening structure, including a shaft body, a hub connecting flange at one end of the shaft body, and a gearbox low-speed shaft connected to the other end of the shaft body through an expansion sleeve. The expansion sleeve includes an outer ring, an inner ring, and several sets of bolts for connecting the outer ring and the inner ring. The ends of the bolts are provided with nuts and anti-loosening components. The number of anti-loosening components corresponds to the number of nuts and is arranged circumferentially at the end of the outer ring. The anti-loosening components can rotate around the bolt axis and are locked and fixed to the end of the outer ring by the nuts. When the anti-loosening components rotate to a preset position, they can prevent the nuts on adjacent bolts from coming off axially.
[0007] Preferably, the anti-detachment component includes a connecting arm, with connecting rings and limiting seats respectively provided at both ends of the connecting arm and fixed to two adjacent sets of bolts by screwing on nuts; the connecting ring is sleeved on one set of bolts, and the limiting seat is provided with a base plate and a limiting plate. The connecting ring and the base plate are staggered back and forth along the axial direction, so that when two adjacent sets of anti-detachment components are fixed by nuts, the base plate is in contact with the end face of the outer ring, and the connecting ring is located outside the base plate; the limiting seat has a through groove, so that after the connecting ring of the anti-detachment component rotates around one set of bolts, the other adjacent set of bolts is inserted through the through groove, and the nut on the bolt is placed between the base plate and the limiting plate.
[0008] Preferably, the base plate is provided with a limiting protrusion, and the end face of the outer ring is provided with a limiting slot that matches the limiting protrusion. Tightening the nut moves the base plate closer to the outer ring and causes the limiting protrusion to engage in the limiting slot to fix the position of the base plate.
[0009] Preferably, the end of the shaft body connected to the low-speed shaft of the gearbox is provided with a first diameter section and a second diameter section in sequence. The inner circumference of the low-speed shaft of the gearbox includes an inner fitting section and an outer fitting section that are clearance-fitted with the first diameter section and the second diameter section, respectively. The transition step between the first diameter section and the second diameter section is in contact with and abuts against the transition step between the inner fitting section and the outer fitting section.
[0010] Preferably, the first diameter segment is symmetrically provided with two sets of limiting grooves, and the low-speed shaft of the gearbox is symmetrically provided with two sets of pin holes. Each set of pin holes is connected to a pin, and one end of the pin is inserted into the limiting groove.
[0011] Preferably, the width of the limiting groove is greater than the diameter of the pin, and elastic pads are provided on both sides of the limiting groove.
[0012] Preferably, the length of the pin is equal to the distance from the bottom of the limiting groove to the outer circumferential wall of the low-speed shaft of the gearbox, and a weak part of the annular groove is provided at the gap between the first diameter section and the inner mating section of the pin.
[0013] Compared with the prior art, this utility model has the following advantages and effects:
[0014] This invention utilizes an anti-loosening component, secured by a nut on one bolt, while a limiting bracket on the anti-loosening component also restricts the nuts on adjacent bolts. This "chain" locking method is simple in structure and easy to install. Even under strong vibration conditions, if a nut shows any tendency to loosen, it will be blocked by the limiting plate of the limiting bracket, preventing it from detaching axially. This improves the safety of the expansion sleeve connection and prevents major fan accidents caused by nut detachment. Attached Figure Description
[0015] Figure 1 This is a perspective view of the anti-loosening structure of an embodiment of this utility model.
[0016] Figure 2 This is a cross-sectional view of the anti-loosening structure of an embodiment of this utility model.
[0017] Figure 3 This is a schematic diagram of the anti-detachment component in an embodiment of this utility model.
[0018] Figure 4 This is a schematic diagram illustrating the working principle of the anti-detachment component in this embodiment of the utility model.
[0019] Figure 5 This is a cross-sectional view of the connection structure of the anti-detachment component in an embodiment of this utility model.
[0020] Figure 6 This is a cross-sectional view of the shaft and the low-speed shaft of the gearbox at the pin in an embodiment of this utility model.
[0021] Figure Numbers: Shaft 1, Hub Connecting Flange 11, First Diameter Section 12, Second Diameter Section 13, Limiting Groove 14, Elastic Pad 15, Gearbox Low Speed Shaft 2, Inner Fitting Section 21, Outer Fitting Section 22, Pin Hole 23, Expansion Sleeve 3, Outer Ring 31, End Face 311, Limiting Slot 312, Inner Ring 32, Bolt 33, Nut 34, Anti-Loosening Part 4, Connecting Arm 41, Connecting Ring 42, Limiting Card Seat 43, Base Plate 431, Limiting Plate 432, Through Groove 433, Limiting Protrusion 434, Pin Shaft 5, Ring Groove Weak Part 51. Detailed Implementation
[0022] The present invention will be further described in detail below with reference to the accompanying drawings and through embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.
[0023] Example:
[0024] See Figure 1 - Figure 6This embodiment relates to a wind turbine main shaft anti-loosening structure, specifically used for the anti-loosening connection and fixation between the main shaft of the cantilever beam structure wind turbine supported by the bearing and the low-speed shaft 2 of the gearbox. The structure includes a shaft body 1, one end of which is provided with a hub connecting flange 11 for connecting the blade hub. The other end of the shaft body 1 is used for connecting to the low-speed shaft 2 of the gearbox.
[0025] Shaft 1 is connected and fixed to the low-speed shaft 2 of the gearbox via a shrink sleeve 3. The shrink sleeve 3 is the main component for torque transmission.
[0026] See Figure 2 The expansion sleeve 3 is a conventional structure, including an outer ring 31, an inner ring 32, and several sets (e.g., 8, 12, or 16 sets, depending on the actual size of the expansion sleeve 3) of bolts 33 for connecting the outer ring 31 and the inner ring 32. By tightening the nut 34 at the end of the bolt 33, the outer ring 31 and the inner ring 32 undergo relative axial displacement. The interaction of their conical surfaces causes the outer ring 31 to expand and the inner ring 32 to contract, thereby respectively gripping the inner hole of the low-speed shaft 2 of the gearbox and the outer circumference of the shaft body 1, generating friction to transmit torque.
[0027] The core improvement of this utility model lies in the provision of a nut 34 and an anti-loosening component 4 at the end of the bolt 33. The number of anti-loosening components 4 corresponds to the number of nuts 34 (or bolts 33) and they are arranged circumferentially on the end face 311 of the outer ring 31.
[0028] Specifically, the anti-detachment component 4 includes a connecting arm 41. A connecting ring 42 and a limiting seat 43 are respectively provided at both ends of the connecting arm 41. The limiting seat 43 consists of a base plate 431 and a limiting plate 432 that bends and extends from the base plate 431.
[0029] See Figure 3 and Figure 4 The connecting ring 42 of the anti-detachment component 4 and the base plate 431 are staggered back and forth along the axial direction (i.e., the axial direction of the bolt 33). During installation, the base plate 431 of the anti-detachment component 4 is in contact with the end face 311 of the outer ring 31, while the connecting ring 42 is located on the outer side of the base plate 431 (i.e., the side further away from the outer ring 31).
[0030] A space is formed between the base plate 431 and the limiting plate 432 of the limiting bracket 43 (large enough to accommodate tools such as wrenches for tightening nuts 34), and a through groove 433 is provided.
[0031] The installation and operation process of this utility model is as follows:
[0032] Step 1: Component Pre-assembly
[0033] First, assemble the expansion sleeve 3 (including the outer ring 31 and the inner ring 32) with the shaft 1 and the low-speed shaft 2 of the gearbox in the designed positions. Then, pass all the bolts 33 through the inner ring 32 (through hole) and the outer ring 31 (threaded hole) in sequence, and make the ends (threaded ends) of the bolts 33 protrude from the end face 311 of the outer ring 31.
[0034] Step 2: Install the anti-detachment parts 4 in an alternating pattern.
[0035] Place the connecting rings 42 of all anti-detachment components 4 onto the corresponding bolts 33, and screw all the nuts 34 onto the corresponding bolts 33 (no need to tighten). Then, rotate the limiting seats 43 of all anti-detachment components 4 around the corresponding bolts 33 in sequence, so that their through slots 433 are aligned with the second bolt 33, and so that the base plate 431 and the limiting plate 432 of the limiting seat 43 are placed on the bolt 33. Install all anti-detachment components 4 in a staggered manner along the circumference, with the connecting rings 42 pressing the base plates 431 of adjacent components, so that all anti-detachment components 4 form a complete staggered stack around the end face 311 of the outer ring 31.
[0036] Step 3: Tighten nut 34
[0037] All nuts 34 are pre-tightened in stages and crosswise, and finally tightened with torque, so that the bottom of the nut 34 simultaneously presses the connecting ring 42 of a set of anti-loosening components 4 and the bottom plate 431 of the adjacent set of anti-loosening components 4 onto the end face 311 of the outer ring 31.
[0038] See Figure 5 After installation, the axial outer side of any nut 34 is blocked by the limiting plate 432 of the adjacent anti-loosening component 4. Even if the nut 34 loosens under strong vibration, it can only rotate within a limited angle, but cannot be dislodged from the bolt 33 axially, thus achieving a reliable anti-loosening effect. The anti-loosening component 4 itself is firmly pressed and fixed by the nut 34, achieving mutual locking.
[0039] This invention utilizes an anti-loosening component 4, secured by a nut 34 on a bolt 33. Simultaneously, the limiting bracket 43 of the anti-loosening component 4 restricts the nuts 34 on adjacent bolts 33. This "chain" locking method is simple in structure and easy to install. Even under strong vibration conditions, if any nut 34 shows signs of loosening, it will be blocked by the limiting plate 432 of the limiting bracket 43, preventing it from detaching axially. This improves the safety of the expansion sleeve 3 connection and prevents major fan accidents caused by nut 34 falling off.
[0040] To further improve the fixing reliability of the anti-loosening component 4 and prevent the anti-loosening component 4 from rotating around the bolt 33 under vibration (or centrifugal force of the shaft 1 rotation), causing the limiting seat 43 to misalign, in this embodiment, a limiting protrusion 434 is provided on the base plate 431 of the anti-loosening component 4. Correspondingly, a limiting slot 312 adapted to the limiting protrusion 434 is provided on the end face 311 of the outer ring 31. When the nut 34 is tightened to bring the base plate 431 closer to the outer ring 31, the limiting protrusion 434 will engage in the limiting slot 312, thereby fixing the position of the base plate 431 (i.e., the entire anti-loosening component 4), limiting the possibility of the limiting seat 43 of the anti-loosening component 4 coming off radially (outward "thrown out") along the bolt 33 under the centrifugal force of high-speed rotation, further ensuring the overall stability of the anti-loosening structure. This utility model provides a limiting protrusion 434 on the base plate 431 of the anti-loosening component 4 and a limiting slot 312 on the end face 311 of the outer ring 31 of the expansion sleeve 3, so that the anti-loosening component 4 can be accurately positioned radially and circumferentially when it is pressed by the nut 34, preventing the anti-loosening component 4 from rotating or misaligning during vibration, and ensuring the long-term reliability of its limiting function.
[0041] See Figure 2 The end of the shaft 1 connected to the low-speed shaft 2 of the gearbox is provided with a first diameter section 12 and a second diameter section 13 in sequence. Correspondingly, the inner circumference (inner hole) of the low-speed shaft 2 of the gearbox includes an inner fitting section 21 and an outer fitting section 22 that respectively have clearance fit with the first diameter section 12 and the second diameter section 13. On the shaft 1, the transition step between the first diameter section 12 and the second diameter section 13 contacts and abuts against the transition step between the inner fitting section 21 and the outer fitting section 22 on the low-speed shaft 2 of the gearbox, thereby achieving axial positioning between the shaft 1 and the low-speed shaft 2 of the gearbox.
[0042] When the shrinking sleeve 3 is overloaded, i.e., when the frictional force cannot provide sufficient torque, relative (slipping) rotation will occur between the shaft 1 and the low-speed shaft 2 of the gearbox. This causes wear on the friction pair structure between the shaft 1, the low-speed shaft 2, and the shrinking sleeve 3, resulting in a gradual decrease in the torque capacity provided by the shrinking sleeve 3 after each overload. Therefore, in this embodiment, two sets of limiting grooves 14 are symmetrically provided on the first diameter section 12 of the shaft 1. Two sets of pin holes 23 are symmetrically provided at corresponding positions on the low-speed shaft 2 of the gearbox. A pin 5 is inserted into each of the two sets of pin holes 23, with one end of the pin 5 extending out of the inner hole of the low-speed shaft 2 of the gearbox and inserted into the limiting groove 14 of the shaft 1. This structure (similar to a flat key connection) can assist the shrinking sleeve 3 in transmitting torque (when the shrinking sleeve 3 is overloaded), thereby reducing frictional loss during overload.
[0043] In this embodiment, the width (circumferential dimension) of the limiting groove 14 is greater than the diameter of the pin 5, allowing the pin 5 a certain amount of play within the limiting groove 14. This allows the pin 5 to be installed without requiring precise alignment between the pin hole 23 and the limiting groove 14, which is convenient for the installation operation of the pin 5. Furthermore, elastic pads 15 (such as high-strength elastic materials like polyurethane) are provided on both side walls (torque-bearing surfaces) of the limiting groove 14. When torque is transmitted, the pin 5 drives the shaft 1 by compressing the elastic pads 15, effectively buffering the impact load of torque (mainly under overload) in the transmission chain, thus playing a shock-absorbing role and protecting the gearbox.
[0044] See Figure 6 The length of the pin 5 is equal to the distance from the bottom of the limiting groove 14 to the outer circumferential wall of the low-speed shaft 2 of the gearbox, making it easy to install and position. During installation, simply tap it in until its end is flush with the outer circumferential wall to indicate that it is in place. More importantly, the pin 5 has an annular groove weak section 51 in the gap between the first diameter section 12 and the inner mating section 21 (i.e., the structural transition zone). This annular groove weak section 51 is the safe shear surface of the pin 5. Under normal torque, it can safely transmit power. When the wind turbine encounters extreme operating conditions (such as a sudden short circuit of the generator caused by a power grid failure or emergency braking, overload, etc.), the torque borne by the transmission chain instantaneously exceeds the design limit, and the pin 5 will first undergo shear fracture at the annular groove weak section 51, which has the effect of overload protection: "sacrificing" the relatively low-cost pin 5 to protect the higher-cost shaft 1 and the gears inside the gearbox from damage.
[0045] The above description in this specification is merely illustrative of the present invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not depart from the content of this specification or exceed the scope defined in the claims, all of which shall fall within the protection scope of this invention.
Claims
1. A wind turbine main shaft anti-loosening structure, comprising a shaft body, a hub connecting flange at one end of the shaft body, and the other end of the shaft body connected to the low-speed shaft of a gearbox via an expansion sleeve, wherein the expansion sleeve comprises an outer ring, an inner ring, and a plurality of sets of bolts for connecting the outer ring and the inner ring, characterized in that: The bolt is provided with a nut and an anti-loosening component at its end. The number of anti-loosening components corresponds to the number of nuts and they are arranged circumferentially at the end of the outer ring. The anti-loosening components can rotate around the bolt axis and are locked and fixed to the end of the outer ring by the nuts. When the anti-loosening components rotate to a preset position, they can prevent the nuts on adjacent bolts from coming off axially.
2. The anti-loosening structure for wind turbine main shaft according to claim 1, characterized in that: The anti-detachment component includes a connecting arm, with a connecting ring and a limiting seat respectively provided at both ends of the connecting arm and fixed to two adjacent sets of bolts by screwing on nuts. The connecting ring is sleeved on one set of bolts, and the limiting seat is provided with a base plate and a limiting plate. The connecting ring and the base plate are staggered along the axial direction, so that when two adjacent sets of anti-detachment components are fixed by nuts, the base plate is in contact with the end face of the outer ring, and the connecting ring is located outside the base plate. The limiting seat has a through groove, so that after the connecting ring of the anti-detachment component rotates around one set of bolts, the other adjacent set of bolts is inserted through the through groove, and the nut on the bolt is placed between the base plate and the limiting plate.
3. The anti-loosening structure for the main shaft of a wind turbine according to claim 2, characterized in that: The base plate is provided with a limiting protrusion, and the end face of the outer ring is provided with a limiting slot that matches the limiting protrusion. Tightening the nut moves the base plate closer to the outer ring and causes the limiting protrusion to engage in the limiting slot to fix the position of the base plate.
4. The anti-loosening structure for the main shaft of a wind turbine according to claim 1, characterized in that: The end of the shaft connected to the low-speed shaft of the gearbox is provided with a first diameter section and a second diameter section in sequence. The inner circumference of the low-speed shaft of the gearbox includes an inner fitting section and an outer fitting section that are clearance-fitted with the first diameter section and the second diameter section, respectively. The transition step between the first diameter section and the second diameter section is in contact with and abuts against the transition step between the inner fitting section and the outer fitting section.
5. The anti-loosening structure for the main shaft of a wind turbine according to claim 4, characterized in that: The first diameter section is symmetrically provided with two sets of limiting grooves, and the low-speed shaft of the gearbox is symmetrically provided with two sets of pin holes. A pin is inserted into each of the two sets of pin holes, and one end of the pin is inserted into the limiting groove.
6. The anti-loosening structure for the main shaft of a wind turbine according to claim 5, characterized in that: The width of the limiting groove is greater than the diameter of the pin, and elastic pads are provided on both sides of the limiting groove.
7. The anti-loosening structure for the main shaft of a wind turbine according to claim 5, characterized in that: The length of the pin is equal to the distance from the bottom of the limiting groove to the outer circumferential wall of the low-speed shaft of the gearbox, and a weak part of the annular groove is provided at the gap between the first diameter section and the inner mating section of the pin.