Axial load shunting system of 2MW wind turbine generator
By installing a load shunt system of cylinders and solenoid valves on the rear side of the spindle of the wind turbine, the problem of overheaval axial load and impact load on the back of the spindle of the wind turbine is solved, and the bearing service life is extended and the stability of the wind turbine operation is improved.
Patent Information
- Application Number
- CN202411610301.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-12
- Publication Date
- 2025-03-07
AI Technical Summary
The rear bearing of the wind turbine spindle bears overheaval axial load and impact load, resulting in increased wear and short service life. The existing unloading device fails to effectively solve the problem of front bearing clearance and insufficient impact load protection.
A 2MW wind turbine axial load shunt system is designed. By installing a cylinder and solenoid valve on the rear side of the front bearing of the spindle, the initial pressure in the cylinder is accurately controlled, the initial axial preload effect is achieved, the position and load state of the unloading device are monitored and adjusted in real time, and the cylinder pressure is dynamically adjusted to compensate for gap changes and wear.
Effectively reduce the axial and impact loads of rear bearings, reduce the risk of failure, extend the service life of the bearing, improve the operating efficiency and stability of the wind turbine, and reduce maintenance costs.
Smart Images
Figure CN119572573A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of wind turbine generators, in particular to an axial load shunting system for a 2MW wind turbine generator set. Background Art
[0002] The main shaft system of a wind turbine adopts a dual-bearing four-point support structure, in which the front bearing has a floating function and mainly bears the radial load of the unit, while the rear bearing has a thrust function. In addition to bearing a large radial load, it also has to bear all axial loads. Therefore, the rear bearing not only needs to bear a large radial load from the wind wheel and the generator, but also all axial loads, which makes the load on the rear bearing more concentrated in long-term operation. Therefore, the wear of the rear bearing of the wind turbine main shaft is usually relatively large, and its life is also relatively short compared to the front bearing. In addition, due to factors such as wind speed fluctuations, unstable rotation of the wind wheel or sudden external forces, the main shaft bearings will be subjected to large axial forces and impact loads. These sudden loads will not only have an adverse effect on the main shaft, main shaft bearings and related transmission systems, but may also cause equipment fatigue, damage, and even system failure.
[0003] Based on the uneven load on the front and rear bearings of the wind turbine and the service life of the rear bearing of the wind turbine, an unloading device for the main shaft bearing of the wind turbine was invented. The application of the unloading device can reduce the axial load on the rear bearing, reduce the wear of the bearing, and increase the service life of the bearing. Its basic working principle is to use the unloading device to make the front bearing also bear part of the axial load, so as to alleviate the working load of the rear bearing, thereby increasing the service life of the bearing, improving system reliability and reducing maintenance costs.
[0004] Most of the existing unloading devices for the main shaft bearings of wind turbines usually act on the front bearing of the main shaft, and are applied to the rear end face of the front bearing through compression springs, disc springs and other components. When the main shaft system of the wind turbine is subjected to axial load, the main shaft moves slightly backward, and the unloading device will press against the rear end face of the front bearing, so that the front bearing shares part of the axial load, reducing the load on the rear bearing, reducing the wear of the rear bearing, and extending its service life. However, the applicant has found that the existing unloading devices fail to fully consider the problem of front bearing clearance.
[0005] In the existing wind turbine main shaft unloading device, although the main goal of the unloading device is to reduce the axial load of the main shaft rear bearing, when the wind turbine main shaft is loaded, the main shaft system may move slightly backward, causing the rear bearing to begin to bear the axial load. As the axial load increases, the clearance of the front bearing gradually decreases until it is completely eliminated, and at this time the unloading device begins to work. The effect of this device is often greatly reduced. The clearance of the front bearing of the wind turbine main shaft means that under the action of the axial load, the main shaft will first move backward, and the main shaft front bearing cannot immediately provide sufficient support or constraint until the backward displacement of the main shaft reaches the clearance range of the front bearing. Therefore, in this process, the rear bearing of the main shaft needs to bear all the axial loads, especially when the backward displacement of the main shaft does not reach the clearance limit of the front bearing, the load borne by the rear bearing is far beyond expectations. This phenomenon not only increases the workload of the spindle rear bearing, but also aggravates the wear of the bearing, affecting the long-term stability and operational reliability of the spindle system. The previous unloading device could only transfer the axial load to the front bearing, but failed to effectively solve the negative impact of the front bearing clearance, resulting in the unloading device being unable to achieve its intended function of reducing the rear bearing load.
[0006] In addition, existing unloading devices fail to provide adequate protection when wind turbines are subjected to strong impact loads or rapidly changing load conditions. During operation, wind turbines may experience strong impact loads or high-frequency vibrations, especially in extreme wind conditions or sudden equipment failures. These impact loads are very damaging to the bearing system, especially the rear bearing of the main shaft. Traditional unloading devices usually lack sufficient energy absorption or buffering capacity and cannot effectively resist such impacts, further exacerbating the loss and failure risk of the bearing system. Summary of the invention
[0007] In view of the deficiencies in the prior art, the present invention reduces the axial load and impact load borne by the rear bearing of the main shaft system of the wind turbine set, thereby effectively reducing the risk of failure caused by excessive load, and reduces the axial force of the main shaft bearing, thereby reducing bearing wear and extending the service life. At the same time, the unloading device improves the operating efficiency of the wind turbine set, ensures the stable operation of the main shaft bearing and other core components in various operating environments, and maintains the smooth operation of the unit, especially when the wind speed is unstable or varies greatly. In addition, the device also effectively reduces the impact force of the gearbox, reduces the risk of gear damage and fatigue fracture, and further improves the reliability and durability of the system.
[0008] To achieve the above object, the technical solution adopted by the present invention is: an axial load diversion system for a 2MW wind turbine, comprising a cylinder fixed on the rear end cover of the front bearing of the main shaft of the wind turbine, and a front cylinder cover and a rear cylinder cover are provided on both axial sides of the cylinder;
[0009] A piston rod is provided at one end of the cylinder, one end of the piston rod is installed in the cylinder and connected to the working piston; the working piston divides the cylinder into two cavities, each cavity is connected to the air guide pipe respectively;
[0010] The two air guide pipes are connected to the solenoid valve; the air inlet end of the solenoid valve is connected to the air compressor;
[0011] A displacement sensor is arranged on the piston rod.
[0012] Furthermore, a piston head is installed at the other end of the piston rod.
[0013] Furthermore, the end surface area of the piston head is larger than the end surface area of the piston rod.
[0014] Furthermore, the piston head is bolted to the end of the piston rod.
[0015] Furthermore, the rear cylinder cover is fixedly connected to the end cover by bolts.
[0016] Furthermore, the solenoid valve is fixed on the end cover.
[0017] Furthermore, buffer pistons are sleeved on the piston rods on both sides of the working piston.
[0018] Furthermore, a displacement sensor is provided on the side of the piston rod close to the rear cylinder cover.
[0019] Furthermore, the displacement sensor is arranged on a buffer piston close to a side of the rear cylinder cover.
[0020] Furthermore, two rubber rings are provided on the outer peripheral wall of the working piston.
[0021] Advantages of the present invention:
[0022] This device precisely controls the initial pressure in the cylinder by adjusting the solenoid valve, thereby achieving the initial axial preload effect, effectively eliminating the impact of the change in the clearance of the front bearing of the wind turbine on the performance of the unloading device, and using a high-precision solenoid valve to monitor the position and load state of the unloading device in real time through the displacement sensor on the piston rod, ensuring that when the bearing clearance changes cause problems, the system can respond and adjust the pressure in time to maintain the efficient operation of the unloading device. In addition, by adjusting the cylinder pressure, it is ensured that the air pressure in the cylinder is sufficient to overcome the inertia and friction caused by the gap, ensuring that the unloading device can be started in the shortest time and avoiding slow response caused by clearance problems. The solenoid valve further ensures a stable gas flow rate to avoid the timeliness and stability of the unloading action affected by too fast or too slow airflow. It can also dynamically adjust the cylinder pressure according to the wear of the bearing, and compensate for the gap changes caused by wear in real time, thereby ensuring that the unloading device is always in the best working condition. Through these precise control methods, the device can not only eliminate the problems caused by bearing clearance fluctuations and wear, but also automatically optimize the adjustment of the unloading force under different loads and working conditions, ensuring that the unloading effect is always stable and reliable, and preventing potential mechanical shock and damage to the wind turbine due to excessive or insufficient unloading. The device not only improves the operating stability and safety of the wind turbine, but also significantly extends the service life of the equipment, reduces maintenance costs, and ensures that the wind turbine can operate efficiently for a long time under various complex working conditions. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 A schematic diagram of the structure of the axial load diversion system of a 2MW wind turbine provided by the present invention;
[0024] Figure 2 A cross-sectional view of the axial load diversion system of a 2MW wind turbine provided by the present invention;
[0025] Among them: front cylinder cover 1, solenoid valve 2, piston head 3, piston rod 4, rear cylinder cover 5, air guide pipe 6, bolt 7, buffer piston 8, displacement sensor 9, working piston 10, cylinder 11, rubber sleeve 12, end cover 13. DETAILED DESCRIPTION
[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0027] The device of the present invention is applied to the main shaft system of a wind turbine, aiming to optimize the load distribution of the main shaft bearing and improve the stability and reliability of the system. The core function of the unloading device is to reduce or eliminate the axial force and impact load on the rear bearing of the wind turbine, thereby effectively reducing the wear of the rear bearing and extending its service life. At the same time, the unloading device can also reduce the impact load on the main shaft system during operation, ensure the smooth operation of the unit, improve its stability and reliability, and extend the overall service life.
[0028] In order to reduce the influence of the front bearing clearance on the unloading effect of the unloading device, a dynamically adjusted unloading device design can be considered. By introducing an air pressure regulation system, the clearance of the front bearing can be adjusted in real time according to actual load changes, thereby reducing the amount of rearward displacement of the spindle when it is under force and avoiding excessive load transfer to the rear bearing. This allows the unloading device to play a role at an earlier stage and reduce the workload of the rear bearing.
[0029] like Figure 1-Figure 2 As shown, this embodiment provides an axial load diversion system for a 2MW wind turbine, comprising a cylinder 11 fixed on a rear end cover 13 of a front bearing of a main shaft of the wind turbine, and a front cylinder cover 1 and a rear cylinder cover 5 are provided on both axial sides of the cylinder 11; the rear cylinder cover 5 is fixedly connected to the end cover 13 by bolts 7;
[0030] The end cover 13 is used to install the load distribution system of this embodiment, and fix the position of the front bearing through the anti-impact unloading device, so that the front bearing is subjected to force and the displacement of the front bearing is reduced;
[0031] A piston rod 4 is provided at one end of the cylinder 11, and one end of the piston rod 4 is installed in the cylinder 11 and connected to the working piston 10; the piston rod 4 is connected to the working piston 10 to convert the pressure of the gas into mechanical motion, and drive or control is achieved through it;
[0032] The front cylinder head 1, the rear cylinder head 5, the cylinder 11 and the working piston 10 together form two closed spaces, each of which is connected to the air guide pipe 6 respectively, and the two air guide pipes 6 are connected to the solenoid valve 2; the air inlet end of the solenoid valve 2 is connected to the air compressor; the forward and backward movement of the piston rod 4 is controlled by changing the pressure difference of the cylinder 11 before and after the working piston 10, and the cylinder 11 is used to support the working piston 10, and as a container to fix the working piston 10 and limit its range of movement, ensure that the piston moves along a certain path in the cylinder 11, play a sealing role, prevent gas leakage during the working process, maintain the pressure inside the cylinder 11, and ensure the normal operation of the cylinder 11. There are air inlets and exhaust ports at the top and bottom of the cylinder 11, which are used to increase or decrease the pressure in the cylinder, thereby driving the piston rod 4;
[0033] A displacement sensor 9 is provided on the piston rod 4, which is responsible for real-time monitoring of the position information of the piston rod 4. By adjusting the solenoid valve 2, the piston rod 4 can contact the outer ring of the bearing in real time, thereby unloading and reducing the impact load.
[0034] In another embodiment of the present application, a piston head 3 is installed at the other end of the piston rod 4, and the end surface area of the piston head 3 is larger than the end surface area of the piston rod 4; the load shunt system with the solenoid valve 2 and the cylinder 11 is fixed to the rear end cover 13 of the front bearing of the wind turbine main shaft, so that the piston head 3 can contact the rear end surface of the front bearing, thereby limiting the displacement of the front bearing and resisting axial loads and axial impacts. The piston head 3 is bolted to the top of the piston rod 4, which increases the force area of the piston rod 4 and can better resist the outer ring of the front bearing.
[0035] In another embodiment of the present application, the solenoid valve 2 is fixed on the end cover 13. The solenoid valve 2 is composed of an electromagnetic coil, a valve core, a valve seat and a spring. When the electromagnetic coil is energized, the generated magnetic field will attract the valve core to open or close the valve core, thereby controlling the flow of gas or liquid, controlling the air intake and exhaust of the cylinder 11, and obtaining the position of the piston rod 4 through the displacement sensor 9. The air pressure in the cylinder 11 and the position of the piston rod 4 are adjusted by controlling the solenoid valve 2.
[0036] In another embodiment of the present application, a buffer piston 8 is sleeved on the piston rod 4 on both sides of the working piston 10; there are two buffer pistons 8, which are sleeved on the piston rod 4 to seal the left and right sides of the piston 10. The main function is to buffer and reduce shock, avoid the sudden stop of the movement of the working piston 10 in the cylinder 11, reduce mechanical shock and noise, and help reduce the collision between the working piston 10 and the cylinder body, thereby reducing the mechanical wear of the device.
[0037] In another embodiment of the present application, a displacement sensor 9 is provided on the side of the piston rod 4 close to the rear cylinder cover 5 .
[0038] In another embodiment of the present application, the displacement sensor 9 is disposed on the buffer piston 8 close to a side of the rear cylinder cover 5 .
[0039] In another embodiment of the present application, the working piston 10 is connected to the piston rod 4. There are two sealing rubber rings 12 on the working piston 10, which form a closed chamber with the cylinder 11. Gas is sucked in through the air inlet to push the working piston 10 to move linearly.
[0040] Installation method and working process
[0041] 1. Fix the load splitting system with the solenoid valve 2 and the cylinder 11 to the rear end cover 13 of the front bearing of the wind turbine main shaft, so that the piston head 3 can contact the rear end surface of the front bearing of the wind turbine, which plays a role in limiting the displacement of the front bearing and resisting the axial load and axial impact.
[0042] 2. Initial position adjustment of piston rod 4
[0043] By adjusting the solenoid valve 2, the air pressure in the cylinder 11 is increased, and the piston rod 4 is pushed to move until the piston head 3 contacts the end face of the outer ring of the front bearing. In this process, the air pressure in the cylinder 11 can be accurately adjusted to apply a certain pre-pressure to reduce the clearance of the front bearing of the wind turbine, thereby ensuring that the unloading device can work effectively.
[0044] 3. Solenoid valve adjusts the pressure in the cylinder
[0045] The electromagnetic valve 2 precisely controls the air pressure in the cylinder 11 to push the movement of the piston rod 4 and adjust the initial pressure in the cylinder 11. When the supporting force needs to be increased, the electromagnetic valve 2 will adjust the switch state to allow the gas to flow into the closed space on the right side of the cylinder 11, thereby increasing the air pressure in the cylinder 11. After the air pressure increases, the piston rod 4 will push the piston head 3 to contact the end face of the front bearing, thereby applying a certain pre-pressure, which reduces the gap between the front bearing and the main shaft, effectively suppresses the axial displacement of the main shaft, and ensures the stable operation of the main shaft.
[0046] 4. System detection and adjustment of the operation of the unloading device
[0047] The displacement sensor 9 installed on the piston rod 4 is used to monitor the displacement change of the front bearing in real time. When the displacement of the front bearing increases, the switch state of the solenoid valve 2 can be manually controlled or controlled by the control system. The control gas is transported to the enclosed space on the right side of the cylinder 11 through the air duct 6. The increase in the air pressure in the cylinder 11 will directly increase the unloading force, thereby enhancing the supporting force for the front bearing and sharing the axial load of the main shaft. According to the actual force condition of the front bearing, the unloading force is dynamically adjusted to accurately protect the main shaft of the wind turbine set, ensuring that the anti-impact unloading device is always in the best working state under various working conditions, extending the service life of the unit and reducing bearing wear.
[0048] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A 2MW wind turbine axial load diversion system, characterized by: It comprises a cylinder (11) fixed on a rear end cover (13) of a front bearing of a main shaft of a wind turbine generator set, wherein a front cylinder cover (1) and a rear cylinder cover (5) are provided on both axial sides of the cylinder (11); A piston rod (4) is provided at one end of the cylinder (11), one end of the piston rod (4) is installed in the cylinder (11) and connected to the working piston (10); the working piston (10) divides the cylinder (11) into two cavities, each cavity is connected to the air guide pipe (6) respectively; The two air guide pipes (6) are connected to the electromagnetic valve (2); the air inlet end of the electromagnetic valve (2) is connected to the air compressor; The piston rod (4) is provided with a displacement sensor (9).
2. The 2MW wind turbine axial load diversion system according to claim 1 is characterized in that: The other end of the piston rod (4) is mounted with a piston head (3).
3. The 2MW wind turbine axial load diversion system according to claim 2 is characterized in that: The end surface area of the piston head (3) is larger than the end surface area of the piston rod (4).
4. The 2MW wind turbine axial load diversion system according to claim 2 or 3, characterized in that: The piston head (3) is bolted to the end of the piston rod (4).
5. The 2MW wind turbine axial load diversion system according to claim 1 is characterized in that: The rear cylinder cover (5) is fixedly connected to the end cover (13) via bolts (7).
6. The 2MW wind turbine axial load diversion system according to claim 1 is characterized in that: The solenoid valve (2) is fixed on the end cover (13).
7. The 2MW wind turbine axial load diversion system according to claim 1 is characterized in that: Buffer pistons (8) are sleeved on the piston rods (4) on both sides of the working piston (10).
8. The 2MW wind turbine axial load diversion system according to claim 1 is characterized in that: A displacement sensor (9) is provided on the side of the piston rod (4) close to the rear cylinder cover (5).
9. The 2MW wind turbine axial load diversion system according to claim 7 is characterized in that: The displacement sensor (9) is arranged on the buffer piston (8) on one side close to the rear cylinder cover (5).
10. The 2MW wind turbine axial load diversion system according to claim 1, characterized in that: Two rubber sleeve rings (12) are provided on the outer peripheral wall of the working piston (10).