Detection device of variable-pitch bearing, variable-pitch system and wind turbine generator

Abstract

The utility model discloses a variable pitch bearing detection device, a variable pitch system and a wind turbine generator, and belongs to the field of wind power. The detection device comprises a shell, the shell is provided with a containing cavity, the shell is provided with a detection face in the first direction, and the detection face is close to the variable pitch bearing in the detection process; the magnetic part, the elastic part and the sensing unit are located in the containing cavity; wherein the magnetic part is close to the detection surface, the elastic part is arranged on one side, deviating from the detection surface, of the magnetic part, the telescopic direction of the elastic part is a first direction, one end of the elastic part is connected with the magnetic part, and the other end of the elastic part is connected with the sensing unit; when the detection device is in the first state, the tensile force of the magnetic part on the elastic part is larger than that of the magnetic part on the elastic part when the detection device is in the second state, the induction unit is configured to send out a crack detection signal in the second state, and the crack detection signal represents that cracks exist in the position, close to the detection face, of the variable-pitch bearing. According to the embodiment of the invention, the crack detection of the variable pitch bearing can be realized.

Description

Technical Field

[0001] This application pertains to the field of wind power, and particularly relates to a testing device for pitch bearings, a pitch system, and a wind turbine. Background Technology

[0002] The pitch system is a crucial component of a wind turbine, and one of its primary functions is to act as the turbine's main braking system. In the event of a turbine malfunction, the pitch system drives the blades to a safe pitch position and applies the brakes to prevent the blades from slipping out of their limit positions under gravity. The turbine blades are mounted on pitch bearings, which are in turn mounted on the hub. The pitch bearings are connected to the output shaft of the pitch motor via a transmission structure. Therefore, they are subjected to significant overturning moments, and being partially exposed, they are susceptible to damage from dust, water mist, and ice, potentially leading to breakage and posing a safety risk. Utility Model Content

[0003] This application provides a pitch bearing detection device, a pitch system, and a wind turbine, which can detect cracks in pitch bearings.

[0004] In a first aspect, embodiments of this application provide a detection device for a pitch bearing, which is applied to a pitch system, the pitch system including a pitch bearing;

[0005] The detection device includes: a housing having a receiving cavity and a detection surface in a first direction, wherein the detection surface is close to the pitch bearing during detection; a magnetic component, an elastic component, and a sensing unit located within the receiving cavity; wherein the magnetic component is close to the detection surface, the elastic component is disposed on the side of the magnetic component away from the detection surface, the extension and contraction direction of the elastic component is the first direction, one end of the elastic component is connected to the magnetic component, and the other end of the elastic component is connected to the sensing unit; when the detection device is in the first state, the elastic component is subjected to a greater pulling force from the magnetic component than when the detection device is in the second state, and the sensing unit is configured to emit a crack detection signal in the second state, the crack detection signal indicating that a crack exists at a location close to the detection surface of the pitch bearing.

[0006] In some possible embodiments, the crack detection signal includes a tensile signal, and the sensing unit includes a tensile sensor and a signal line; the tensile sensor is connected to the other end of the elastic element and is configured to acquire the tensile signal of the tensile force applied to the elastic element; the signal line is connected to the tensile sensor for transmitting the tensile signal.

[0007] In some possible embodiments, the sensing unit includes a first contact structure and a second contact structure disposed opposite to the first contact structure; the first contact structure is connected to the other end of the elastic member so that the first contact structure has a degree of freedom of movement along a first direction within the receiving cavity with the elastic member; one of the first contact structure and the second contact structure is connected to the positive terminal of the power supply, and the other is connected to the negative terminal of the power supply; in a first state, the first contact structure and the second contact structure are separated; in a second state, the first contact structure and the second contact structure are in contact, and the circuit including the first contact structure, the second contact structure and the power supply is turned on, and a crack detection signal is output.

[0008] In some possible embodiments, the detection device further includes an alarm unit connected in series in a circuit including a first contact structure, a second contact structure, and a power supply. The alarm unit is configured to issue an alarm signal in response to a crack detection signal. The detection device also includes a power supply.

[0009] In some possible embodiments, the sensing unit further includes a contact support member; the contact support member is fixedly disposed in the receiving cavity, and the contact support member is provided with a moving channel extending along a first direction, the first contact structure and the second contact structure extend into the moving channel, and the first contact structure has a degree of freedom of movement within the moving channel.

[0010] Secondly, embodiments of this application provide a pitch system, including: a hub; a pitch bearing connected to the hub; and a detection device for the pitch bearing disposed within the hub, the detection surface of the detection device being close to the pitch bearing.

[0011] In some possible embodiments, the pitch system further includes: a connecting plate that connects the pitch bearing to the hub; and a bracket disposed on the connecting plate and detachably connected to the detection device so that the detection surface of the detection device is close to the pitch bearing.

[0012] In some possible embodiments, the number of detection devices is four or more, and the detection devices are distributed at circumferential intervals along the pitch bearing.

[0013] In some possible embodiments, the pitch system further includes a pitch control cabinet connected to the sensing unit and configured to power the sensing unit and / or receive crack detection signals.

[0014] Thirdly, embodiments of this application provide a wind turbine generator, including the pitch system of the second aspect.

[0015] This application provides a pitch bearing detection device, a pitch system, and a wind turbine. The pitch bearing detection device includes a housing, and a magnetic component, an elastic component, and a sensing unit within the housing. The magnetic component is positioned near the detection surface of the pitch bearing near the housing for detection. The elastic component is positioned on the side of the magnetic component away from the detection surface, with one end connected to the magnetic component and the other end connected to the sensing unit. The magnetic force between the magnetic component and the measured part of the pitch bearing near the detection surface is inversely proportional to the distance between the magnetic component and the measured part. The greater the magnetic force, the greater the pulling force exerted on the elastic component, and correspondingly, the greater the force exerted on the sensing unit by the elastic component. In the first state where the detection device is in the detection surface near the pitch bearing without cracks, the tension on the elastic element is greater than in the second state where the detection device is in the detection surface near the pitch bearing with cracks. When the detection surface is near the pitch bearing with cracks, the sensing unit will send a crack detection signal to remind the user that there is a crack in the detected part of the pitch bearing, thereby realizing the detection of cracks in the pitch bearing. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the structure of a pitch bearing detection device provided in an embodiment of this application;

[0018] Figure 2 A schematic diagram of the structure of a pitch bearing detection device provided in another embodiment of this application;

[0019] Figure 3 A schematic diagram of the structure of a pitch bearing detection device provided in another embodiment of this application;

[0020] Figure 4 A schematic diagram of the structure of a pitch bearing detection device provided in another embodiment of this application;

[0021] Figure 5 A schematic diagram of the structure of a pitch bearing detection device provided in another embodiment of this application;

[0022] Figure 6 This is a schematic diagram of the structure of a pitch system provided in an embodiment of this application;

[0023] Figure 7 This is a schematic diagram of the structure of a pitch system provided in another embodiment of this application. Detailed Implementation

[0024] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0025] The pitch system is a crucial component of a wind turbine, serving as its primary braking system. In the event of a turbine malfunction, the pitch system drives the blades to a safe pitch position and applies the brakes to prevent slippage under gravity and out of their designated positions. The turbine blades are mounted on pitch bearings, which are in turn mounted on the hub. Connected to the output shaft of the pitch motor via a transmission structure, the pitch bearings are subjected to significant overturning moments. Being partially exposed, they are susceptible to damage from dust, water mist, and freezing temperatures, increasing the risk of breakage. Since the blades are mounted on the moving coil of the pitch bearing, this can even lead to blade detachment, posing a serious safety hazard. Therefore, inspecting the pitch bearings is of paramount importance. Currently, methods such as current pulse testing, ultrasonic testing, and wiring harness loop testing are used to inspect pitch bearings. However, these methods can only detect abnormalities in the pitch bearing and cannot pinpoint the location or extent of a breakage. During operation and maintenance, the location of the fracture may be missed, resulting in the pitch bearing operating with damage, which increases the safety risk.

[0026] This application provides a detection device for pitch bearings, a pitch system, and a wind turbine. The detection device may be equipped with magnetic and elastic components. By utilizing the difference between the distance between the detection device and the non-cracked part of the pitch bearing and the distance between the detection device and the cracked part of the pitch bearing, as well as the relationship between distance and magnetic force, a crack detection signal is emitted to determine whether a crack exists at the detected location of the pitch bearing. This enables the detection of cracks in the pitch bearing, avoids the operation of the pitch bearing with damage, improves the safety of the pitch bearing, and thus improves the safety of the wind turbine.

[0027] The following describes the testing device for the pitch bearing, the pitch system, and the wind turbine provided in this application.

[0028] The first aspect of this application provides a detection device for a pitch bearing, which can be applied to a pitch system, the pitch system including the pitch bearing. Figure 1 This is a schematic diagram of the structure of a pitch bearing detection device provided in one embodiment of this application. Figure 2This is a schematic diagram of the structure of a pitch bearing detection device provided in another embodiment of this application, as shown below. Figure 1 and Figure 2 As shown, the detection device for the pitch bearing includes a housing 11, and a magnetic element 12, an elastic element 13, and a sensing unit 14 located inside the housing.

[0029] The housing 11 has a receiving cavity 15, within which the magnetic element 12, the elastic element 13, and the sensing unit 14 are located. The housing 11 has a detection surface 111 in a first direction. The detection surface 111 can be brought close to the pitch bearing being tested to detect whether the pitch bearing has cracks. That is, during the testing process, the detection surface 111 is close to the pitch bearing. The first direction can be the length direction of the testing device. The detection surface 111 forms a certain angle with the first direction, and the angle α between the detection surface 111 and the first direction can be set according to the usage. For example, an operator can hold the testing device and bring the detection surface 111 close to the pitch bearing. To facilitate the operator holding the testing device, it can be arranged as follows: Figure 1 As shown, the angle α between the detection surface 111 and the first direction is less than 90 degrees, and the detection surface 111 is an inclined plane. For example, the detection device can be fixed inside the hub of the pitch system. To reduce the influence of gravity, such as... Figure 2 As shown, the angle α between the detection surface 111 and the first direction can be equal to 90 degrees, that is, the detection surface 111 can be perpendicular to the first direction, and the detection surface 111 is a vertical surface. In some examples, in order to better locate the crack in the pitch bearing, the size of the detection surface 111 can be slightly larger than the crack size, that is, the difference between the size of the detection surface 111 and the crack size can be within a preset range, and the crack size can be determined based on experiments, experience, etc.

[0030] The magnetic component 12 is magnetic and may include, but is not limited to, permanent magnets, electromagnets, etc. The magnetic component 12 is positioned close to the detection surface 111, with a certain distance between them. The magnetic component 12 can move freely within the housing 11 along a first direction. In some examples, the side of the magnetic component 12 closest to the detection surface 111 may be parallel to the detection surface 111.

[0031] An elastic element 13 is disposed on the side of the magnetic element 12 facing away from the detection surface 111. The elastic element 13 is elastic and can extend and retract in a first direction, that is, the direction of extension and retraction of the elastic element is the first direction. The extension and retraction distance of the elastic element 13 varies depending on the force applied. One end of the elastic element 13 is connected to the magnetic element 12, and the other end is connected to the sensing unit 14. The elastic element 13 may include, but is not limited to, a spring.

[0032] The sensing unit 14 can generate a crack detection signal based on the force exerted on the sensing unit 14 by the tension of the elastic element by the magnetic element. The crack detection signal indicates that a crack exists at a location close to the detection surface 111 of the pitch bearing.

[0033] The magnetic force between the magnetic element 12 and the measured part of the pitch bearing is related to the distance between the magnetic element 12 and the measured part of the pitch bearing. Specifically, the magnetic force between the magnetic element 12 and the pitch bearing is negatively correlated with the distance between the magnetic element 12 and the pitch bearing. For example, the relationship between the magnetic force and the distance can be shown in the following equation (1):

[0034]

[0035] Where F(d) is the magnetic force between the magnetic component 12 and the measured part of the pitch bearing; K is a constant coefficient; m1 is the magnetic moment of the magnetic component 12; m2 is the magnetic moment of the measured pitch bearing; and d is the distance between the magnetic component 12 and the measured part of the pitch bearing. From the above equation (1), it can be seen that the closer the distance, the greater the magnetic force; the farther the distance, the smaller the magnetic force; for example, when the distance is reduced by half, the magnetic force increases by four times; when the distance is doubled, the magnetic force decreases by four times. That is, the magnetic force and the distance have an inverse proportional relationship.

[0036] When the magnetic force of the magnetic element 12 changes, the force exerted by the magnetic element 12 on the elastic element 13 will change accordingly, thereby pulling the elastic element 13 to extend or retract. Correspondingly, the force exerted by the elastic element 13 on the sensing unit 14 will also change. The sensing unit 14 may generate or not generate a signal depending on the force it receives, or the sensing unit 14 may generate different signals depending on the force it receives.

[0037] When the detection surface 111 of the detection device is close to a crack-free area of ​​the pitch bearing, the magnetic element 12 is stretched due to the magnetic force between the magnetic element 12 and the metal surface of the pitch bearing. The elastic element 13 is also subjected to a pulling force from the magnetic element 12, which is F1. At this time, the detection device is in the first state. When the detection surface 111 of the detection device is close to a cracked area of ​​the pitch bearing, the distance between the magnetic element 12 and the metal increases due to the presence of the crack, causing a sudden decrease in magnetic force. This change in magnetic force is reflected in the change in the pulling force of the elastic element 13 from the magnetic element 12, i.e., the pulling force of the elastic element 13 from the magnetic element 12 decreases from F1 to F2. Correspondingly, the force exerted on the sensing unit 14 by the elastic element 13 also decreases. At this time, the detection device is in the second state. The sensing unit 14 senses the decrease in force, reacts, and outputs a crack detection signal. In other words, when the detection device is in its first state, the tension exerted by the magnetic element on the elastic element is greater than that when the detection device is in its second state. The sensing unit is configured to emit a crack detection signal in the second state. This crack detection signal indicates the presence of a crack near the detection surface of the pitch bearing. The first state includes the portion of the pitch bearing near the detection surface 111 of the detection device that does not have a crack; or, more specifically, the first state includes the state where the tension exerted by the magnetic element 12 on the elastic element 13 is greater than or equal to a preset tension. The second state includes the state where the portion of the pitch bearing near the detection surface 111 of the detection device has a crack; or, more specifically, the second state includes the state where the tension exerted by the magnetic element 12 on the elastic element 13 is less than the preset tension.

[0038] In this embodiment, the pitch bearing detection device includes a housing 11, and a magnetic element 12, an elastic element 13, and a sensing unit 14 disposed within the housing 11. The magnetic element 12 is positioned near the detection surface 111 of the housing 11 for approaching and detecting the pitch bearing. The elastic element 13 is disposed on the side of the magnetic element 12 away from the detection surface 111. One end of the elastic element 13 is connected to the magnetic element 12, and the other end is connected to the sensing unit 14. The magnetic force between the magnetic element 12 and the measured part of the pitch bearing near the detection surface 111 is inversely proportional to the distance between the magnetic element 12 and the measured part. The greater the magnetic force, the greater the pulling force exerted on the elastic element 13, and correspondingly, the greater the force exerted on the sensing unit 14 by the elastic element. In the first state, where the detection device is positioned near the crack-free area of ​​the pitch bearing on the detection surface 111, the tension on the elastic element is greater than in the second state, where the detection device is positioned near the cracked area of ​​the pitch bearing on the detection surface 111. When the detection surface 111 is near the cracked area of ​​the pitch bearing, the sensing unit 14 emits a crack detection signal, alerting the user to the presence of a crack in the detected area of ​​the pitch bearing. This enables the detection of cracks in the pitch bearing and allows for location of the crack for maintenance, improving the safety of the pitch system and the wind turbine. The magnetic element 12 in the detection device actively generates magnetism, making it less susceptible to interference from the surrounding environment. The detection is less affected by orientation and does not require the detection surface 111 to be strictly perpendicular to the pitch bearing surface. The detection device has a simple structure and uses a non-contact detection method, preventing the ingress of foreign objects or dust into the pitch bearing crack.

[0039] In some embodiments, the sensing unit includes a tensile sensor and a signal line, and correspondingly, the crack detection signal includes a tensile signal. Figure 3 This is a schematic diagram of the structure of a pitch bearing detection device provided in another embodiment of this application, as shown below. Figure 3 As shown, the tension sensor 141 is connected to the other end of the elastic element 13, and the signal line 142 is connected to the tension sensor 141. The tension sensor 141 is configured to acquire a tension signal from the tension force acting on the elastic element 13. The signal line 142 is used to transmit this tension signal. The tension sensor may have a power supply, which may be located inside the housing 11, or an external power supply outside the housing 11 may be used to power the tension sensor.

[0040] When the detection surface 111 of the detection device is close to a crack-free area of ​​the pitch bearing, the magnetic element 12 is stretched due to the magnetic force between the magnetic element 12 and the metal surface of the pitch bearing. The elastic element 13 is also subjected to the tension of the magnetic element 12. Correspondingly, the tension exerted by the elastic element 13 on the tension sensor 141 is relatively greater. The tension sensor 141 transmits the tension signal through the signal line 142. At this time, the tension signal represents a greater tension, and the detection device is in the first state. When the detection surface 111 of the detection device is close to a cracked area of ​​the pitch bearing, the distance between the magnetic element 12 and the metal increases due to the presence of the crack, causing a sudden decrease in magnetic force. The tension exerted by the magnetic element 12 on the elastic element 13 decreases. Correspondingly, the tension exerted by the elastic element 13 on the tension sensor 141 is relatively smaller. The tension sensor 141 transmits the tension signal through the signal line 142. At this time, the tension signal represents a smaller tension, and the detection device is in the second state. It should be noted that the tensile signal output by the sensing unit 14 in the second state is the crack detection signal, which can characterize the presence of a crack at the location where the pitch bearing is close to the detection surface 111.

[0041] In some examples, the detection device may also include a controller connected to signal line 142. The controller may be configured to determine whether a crack exists near the detection surface 111 of the pitch bearing based on a crack detection signal determined from the tensile signal. The controller can determine whether the tensile signal is a crack signal based on the magnitude of the tensile force represented by the tensile signal, thereby determining whether a crack exists in the pitch bearing and its location. The controller may be housed within the housing 11 or as an external structure outside the housing 11. For example, Figure 4 This is a schematic diagram of the structure of a pitch bearing detection device provided in another embodiment of this application, as shown below. Figure 4 As shown, signal line 142 can extend out of housing 11 and connect to controller 16 located outside housing 11 to transmit the tension signal to controller 16. The controller can be a standalone controller or a controller from the pitch control cabinet in the pitch system; there is no limitation on this.

[0042] In other embodiments, the sensing unit 14 can be implemented using a contact structure. Figure 5 This is a schematic diagram of the structure of a pitch bearing detection device provided in another embodiment of this application, as shown below. Figure 5As shown, the sensing unit 14 may include a first contact structure 143 and a second contact structure 144 disposed opposite to the first contact structure 143. The first contact structure 143 is connected to the other end of the elastic member 13, so that the first contact structure 143 has a degree of freedom of movement along a first direction within the receiving cavity 15 with the elastic member 13. One of the first contact structure 143 and the second contact structure 144 is connected to the positive terminal of the power supply 18, and the other is connected to the negative terminal of the power supply 18. The crack detection signal may include a switching signal, which is an electrical signal. In other words, if an electrical signal is generated, it can be considered that a crack detection signal has been generated.

[0043] In the first state, the first contact structure 143 and the second contact structure 144 are separated. The specific details of the first state can be found in the relevant descriptions in the above embodiments, and will not be repeated here. Because the elastic element 13 experiences a relatively greater pulling force from the magnetic element 12 in the first state, the elastic element 13 will drive the first contact structure 143 to move towards the magnetic element 12, causing the first contact structure 143 to move away from the second contact structure 144, thereby separating the first contact structure 143 and the second contact structure 144. The circuit including the first contact structure 143, the second contact structure 144, and the power supply 18 is in an open-circuit state and will not generate an electrical signal, i.e., no crack detection signal will be generated.

[0044] In the second state, the first contact structure 143 is in contact with the second contact structure 144. The specific details of the second state can be found in the relevant descriptions in the above embodiments, and will not be repeated here. Because the elastic element 13 experiences less tension from the magnetic element 12 in the second state, the elastic element 13 rebounds, thereby pushing the first contact structure 143 towards the second contact structure 144, bringing the first contact structure 143 close to the second contact structure 144, thus bringing the first contact structure 143 and the second contact structure 144 into contact. If the first contact structure 143 and the second contact structure 144 are in contact, the circuit including the first contact structure, the second contact structure, and the power supply is turned on, and a crack detection signal is output. The electrical signal generated by this circuit is the crack detection signal.

[0045] In some examples, the detection device may also include an alarm unit 17, such as Figure 5As shown, the alarm unit 17 is connected in series in a circuit including a first contact structure 143, a second contact structure 144, and a power supply 18. The alarm unit 17 is configured to issue an alarm signal in response to a crack detection signal. When the first contact structure 143 and the second contact structure 144 are in contact, the circuit including the first contact structure 143, the second contact structure 144, and the power supply 18 is turned on. The alarm unit 17, connected in series in this circuit, receives an electrical signal, i.e., a crack detection signal, thereby issuing an alarm signal. The alarm unit 17 can be disposed within the housing 11, or embedded in the housing 11 with a portion of the alarm unit 17 exposed outside the housing 11. The alarm unit 17 can also be disposed outside the housing 11; this is not limited here. For example, the alarm unit 17 includes an indicator light, which can be exposed outside the housing 11. In the second state, i.e., when the first contact structure 143 and the second contact structure 144 are in contact, the indicator light is energized and illuminates. The alarm signal can be implemented as a light signal emitted by the indicator light to indicate the detection of a crack in the pitch bearing. For example, the alarm unit 17 includes a buzzer or a speaker, which may be disposed inside the housing 11. In the second state, i.e., when the first contact structure 143 and the second contact structure 144 are in contact, the buzzer is energized to emit a buzzing sound, or the speaker is energized to emit a sound. The alarm signal can be realized as the buzzer of the buzzer or the sound of the speaker to indicate that a crack in the pitch bearing has been detected.

[0046] The power supply 18 that supplies power to the first contact structure 143 and the second contact structure 144 can be located inside or outside the housing 11, and is not limited thereto. For example, if the power supply 18 is located outside the housing 11, the power supply 18 can be implemented as the pitch control cabinet of the pitch system. In some examples, the detection device may also include the power supply 18.

[0047] In some examples, the first contact structure 143 and the second contact structure 144 can be connected to a controller, which can be located inside or outside the housing 11, without limitation. The controller can determine the presence of a crack near the detection surface of the pitch bearing upon receiving a crack detection signal. In some examples, the controller can reuse a controller from the pitch control cabinet, such as a programmable logic controller (PLC).

[0048] In some examples, the sensing unit 14 may also include a contact support 145. For example... Figure 5As shown, the contact support 145 can be fixedly disposed within the receiving cavity 15. The contact support 145 is provided with a movable channel 146 extending along a first direction. The movable channel 146 can be an opening in the contact support 145 to support the first contact structure 143 and the second contact structure 144. The first contact structure 143 and the second contact structure 144 extend into the movable channel 146, and the first contact structure 143 has a degree of freedom of movement within the movable channel 146, that is, the first contact structure 143 can move freely along the first direction within the movable channel 146.

[0049] In the first state, the first contact structure 143 and the second contact structure 144 are separated. Because the elastic element 13 experiences a relatively greater pulling force from the magnetic element 12 in the first state, the elastic element 13 will cause the first contact structure 143 to move towards the magnetic element 12 in the movement channel 146, thus moving the first contact structure 143 away from the second contact structure 144, thereby separating the first contact structure 143 and the second contact structure 144. The circuit including the first contact structure 143, the second contact structure 144, and the power supply 18 is in an open-circuit state, and no crack detection signal is generated.

[0050] In the second state, the first contact structure 143 is in contact with the second contact structure 144. Because the elastic element 13 experiences less tension from the magnetic element 12 in the second state, it rebounds, pushing the first contact structure 143 towards the second contact structure 144 in the movement channel 146, bringing it close to the second contact structure 144, thus bringing them into contact. If the first contact structure 143 and the second contact structure 144 are in contact, the circuit including the first contact structure, the second contact structure, and the power supply is activated, outputting a crack detection signal.

[0051] A second aspect of this application provides a pitch system. Figure 6 This is a schematic diagram of the structure of a pitch system provided in an embodiment of this application, as shown below. Figure 6 As shown, the pitch system may include a hub 21, a pitch bearing 22, and the detection device 10 in the above embodiments. For details regarding the detection device 10, please refer to the relevant descriptions of the detection device in the above embodiments; they will not be repeated here.

[0052] The hub 21 serves as the mechanical support structure for the wind turbine rotor. The pitch bearing 22 is connected to the hub 21 and connects to the blades. The pitch bearing 22 drives the blades to rotate, thus achieving pitch control. A detection device 10 is located inside the hub 21, with its detection surface 111 close to and opposite the pitch bearing 22. The pitch bearing 22 has a certain thickness, such as approximately 20 centimeters. The detection device 10 can move relative to the pitch bearing 22. When the detection surface 111 of the detection device 10 moves to the location of a crack in the pitch bearing 22, the detection device 10 can issue a crack detection signal.

[0053] The pitch system may further include a pitch control cabinet 23, which is disposed inside the hub 21. The pitch control cabinet 23 can control the pitch system and drive the pitch motor to operate, thereby controlling the pitch. The detection device 10 can be connected to the pitch control cabinet 23 via a connecting cable 24. In this embodiment, the pitch control cabinet 23 can be configured to supply power to the sensing unit 14 in the detection device 10 and / or receive crack detection signals. The crack detection signals generated by the detection device 10 can be transmitted to the pitch control cabinet 23 via the connecting cable 24, and / or the pitch control cabinet 23 can supply power to the sensing unit 14 in the detection device 10 via the connecting cable 24.

[0054] In some examples, a user can hold the inspection device 10 and slowly move it along the inner side of the pitch bearing 22 to inspect for cracks at each location of the pitch bearing 22.

[0055] In other examples, embodiments of this application can also achieve automatic detection by the detection device 10. Figure 7 This is a schematic diagram of the structure of a pitch system provided in another embodiment of this application, as shown below. Figure 7 As shown, the pitch system may also include a connecting plate 25 and a bracket 26.

[0056] A connecting plate 25 connects the pitch bearing 22 to the hub 21. Specifically, the connecting plate 25 connects the stationary ring of the pitch bearing 22 and the hub 21. A bracket 26 can be mounted on the connecting plate 25 and is detachably connected to the detection device 10 so that the detection surface 111 of the detection device 10 is close to the pitch bearing 22. The distance between the detection surface 111 of the detection device 10 and the pitch bearing is the detection distance. When the pitch bearing 22 rotates, the pitch bearing 22 rotates relative to the connecting plate 25, while the bracket 26 and the detection device 10 mounted on the bracket 26 remain stationary relative to the connecting plate 25 and do not rotate with the pitch bearing 22. The rotation of the pitch bearing 22 relative to the bracket 26 and the detection device 10 mounted on the bracket 26 enables automatic non-contact detection of the pitch bearing 22.

[0057] When the pitch bearing 22 rotates, i.e., pitch is adjusted, the detection device 10 and the inner surface of the pitch bearing 22 will undergo relative displacement, allowing for crack detection of the pitch bearing 22 during the pitch adjustment process. Since the pitch range is typically 0 to 90 degrees during wind turbine operation, a quarter of the circumference of the pitch bearing 22 can be detected. To enable comprehensive inspection of the pitch bearing 22, four or more detection devices 10 can be installed; that is, the number of detection devices 10 is four or more. These four or more detection devices 10 are spaced apart circumferentially along the pitch bearing 22. Furthermore, the four or more detection devices 10 can be evenly distributed circumferentially along the pitch bearing 22, enabling inspection of the pitch bearing 22's circumference from 0 to 360 degrees.

[0058] The third aspect of this application provides a wind turbine generator, which includes the pitch system in the above embodiments. For details of the pitch system, please refer to the relevant descriptions in the above embodiments, which will not be repeated here.

[0059] It should be noted that the specific details of the pitch system embodiment and the wind turbine embodiment can be found in the relevant descriptions of the above-mentioned detection device embodiment, which can achieve the same technical effect, and will not be repeated here.

[0060] It should be clarified that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. This application is not limited to the specific structures described above and shown in the figures. Those skilled in the art can make various changes, modifications, and additions after understanding the spirit of this application. Furthermore, for the sake of brevity, detailed descriptions of known structural technologies are omitted here.

[0061] Those skilled in the art will understand that the above embodiments are exemplary and not restrictive. Different technical features appearing in different embodiments can be combined to achieve beneficial effects. Based on a study of the drawings, specification, and claims, those skilled in the art should be able to understand and implement other variations of the disclosed embodiments. In the claims, the term "comprising" does not exclude other means or steps; the quantifier "a" does not exclude a plurality; the terms "first" and "second" are used to identify names and not to indicate any particular order. Any reference numerals in the claims should not be construed as limiting the scope of protection. The appearance of certain technical features in different dependent claims does not mean that these technical features cannot be combined to achieve beneficial effects.

Claims

1. A testing device for pitch bearings, characterized in that, Applied to a pitch system, the pitch system including a pitch bearing; The detection device includes: The housing has a receiving cavity and a detection surface in a first direction, which is close to the pitch bearing during the detection process; The magnetic element, elastic element, and sensing unit are located within the receiving cavity; Wherein, the magnetic component is close to the detection surface, the elastic component is disposed on the side of the magnetic component away from the detection surface, the extension and contraction direction of the elastic component is the first direction, one end of the elastic component is connected to the magnetic component, and the other end of the elastic component is connected to the sensing unit; When the detection device is in the first state, the tension of the elastic element on the magnetic element is greater than the tension of the elastic element on the magnetic element when the detection device is in the second state. The sensing unit is configured to emit a crack detection signal in the second state. The crack detection signal indicates that there is a crack at a position close to the detection surface of the pitch bearing.

2. The detection device according to claim 1, characterized in that, The crack detection signal includes a tensile signal, and the sensing unit includes a tensile sensor and a signal line; The tension sensor is connected to the other end of the elastic element and is configured to collect the tension signal of the tension force applied to the elastic element; The signal line is connected to the tension sensor and is used to transmit the tension signal.

3. The detection device according to claim 1, characterized in that, The sensing unit includes a first contact structure and a second contact structure disposed opposite to the first contact structure. The first contact structure is connected to the other end of the elastic member so that the first contact structure has a degree of freedom of movement along the first direction within the receiving cavity along with the elastic member. One of the first contact structure and the second contact structure is connected to the positive terminal of the power supply, and the other is connected to the negative terminal of the power supply. In the first state, the first contact structure is separated from the second contact structure; in the second state, the first contact structure is in contact with the second contact structure, and the circuit including the first contact structure, the second contact structure and the power supply is turned on, and the crack detection signal is output.

4. The detection device according to claim 3, characterized in that, The detection device further includes an alarm unit, which is connected in series in a circuit including the first contact structure, the second contact structure and the power supply. The alarm unit is configured to issue an alarm signal in response to the crack detection signal. The detection device also includes the power supply.

5. The detection device according to claim 3, characterized in that, The sensing unit also includes a contact support component; The contact support is fixedly disposed in the receiving cavity. The contact support is provided with a moving channel extending along a first direction. The first contact structure and the second contact structure extend into the moving channel, and the first contact structure has a degree of freedom of movement within the moving channel.

6. A pitch control system, characterized in that, include: Wheel hub; The pitch bearing connected to the hub; A detection device for a pitch bearing as described in any one of claims 1 to 5, disposed within the hub, wherein the detection surface of the detection device is close to the pitch bearing.

7. The pitch system according to claim 6, characterized in that, Also includes: A connecting plate that connects the pitch bearing to the hub; A bracket, mounted on a connecting plate, is detachably connected to the detection device so that the detection surface of the detection device is close to the pitch bearing.

8. The pitch system according to claim 6 or 7, characterized in that, The number of the detection devices is four or more, and the detection devices are distributed at intervals along the circumference of the pitch bearing.

9. The pitch system according to claim 7, characterized in that, Also includes: A pitch control cabinet, connected to the sensing unit, is configured to power the sensing unit and / or receive the crack detection signal.

10. A wind turbine generator set, characterized in that, Includes the pitch system as described in any one of claims 6 to 9.

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