On-line monitoring device and system for variable pitch bearing fixing bolt

Abstract

The utility model relates to the field of wind power generation, and discloses a variable pitch bearing fixing bolt on-line monitoring device and system, a variable pitch bearing is installed on a wind driven generator blade through a plurality of fixing bolts and nuts which are uniformly arranged in a circle, and the on-line monitoring device comprises a loop nut with a through hole, a connecting rope and a sensing device. One end of the connecting rope is fixed on the loop nut, and the other end of the connecting rope sequentially penetrates through all the through holes and then is connected with the sensing device. When the fixing bolts are broken, the connecting rope is pulled, the control sensing device feeds back a breakage signal, sensors do not need to be arranged at the positions of all the bolts, and the overall device is low in cost. The on-line monitoring system comprises the on-line monitoring device, a signal receiver, a variable-pitch PLC and a booster station remote monitoring system, the on-line monitoring device on each blade feeds a fracture signal back to the signal receiver, the signal receiver transmits the signal to the variable-pitch PLC, the booster station remote monitoring system gathers the signal of each variable-pitch PLC, and the signal of each variable-pitch PLC is transmitted to the signal receiver. And the real-time monitoring of the bolt fracture condition is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of wind power generation, and more specifically, to an online monitoring device and system for fixing bolts of a variable pitch bearing. Background Art

[0002] With the development of wind power generation equipment, the equipment is developing towards a larger single-unit capacity. The variable-pitch type unit has become the current mainstream due to its irreplaceable performance advantages. The blades of the variable-pitch type unit can be changed in real time according to the wind speed to change the wind energy capture situation. When the wind speed is less than the rated wind speed of the unit, as much wind energy as possible is captured. When the wind speed is greater than the rated wind speed of the unit, the excess wind energy is discarded to protect the equipment from overloading. In the variable-pitch type wind turbine generator set, the variable pitch function is realized by the variable pitch bearing, and the outer ring of the variable pitch bearing is fixed to the blade by a fixing bolt. When the wind turbine is operating normally, the blade rotates with the wind rotor. Under the action of the blade gravity, the rotational centrifugal force and the wind energy load, the fixing bolts not only bear the tensile preload of the blade, but also bear the alternating shear force caused by the rotation of the blade. The blade fixing bolts are prone to breakage under the action of the alternating shear force. After the blade fixing bolt breaks, if the fracture cannot be detected in time, the broken bolt will damage other equipment in the hub and increase the risk of blade falling as the wind rotor rotates.

[0003] At present, the monitoring technology for the fracture of blade fixing bolts generally adopts phased array online monitoring and other means for monitoring, that is, a sensor is installed on each bolt, and the pressure data is transmitted to the server for analysis. In the prior art, for example, Chinese patent CN118030403A discloses a method for monitoring the fracture of high-strength bolts in the variable pitch system of a wind turbine: before the blade is connected to the bearing, a force-sensitive resistor is placed in the gasket slot of the high-strength bolt, a wire slot is arranged next to the flange between the two bolts at the root of the wind turbine blade, and the wiring is installed in the wire slot and connected to the force-sensitive resistor; the force-sensitive resistors on all bolts are connected in series, one end of the series node is connected to the high level +24V, and the other end is connected to the open spare contact of the control system, and connected to the PLC controller; when the high-strength bolt is broken, the potential of the force-sensitive resistor changes, and the blade controller transmits it back to the main control through the variable pitch communication, and the main control controls the wind turbine to stop according to the command. However, such a bolt fracture detection method requires the installation of a force-sensitive resistor on each bolt, resulting in a high installation cost of the monitoring system, which is not suitable for large-scale production. Utility Model Content

[0004] In order to solve the problem that the monitoring system for the fracture of fixing bolts is costly and not suitable for large-scale production, the utility model provides an online monitoring device and system for the fixing bolts of variable pitch bearings, which realizes the monitoring of the fracture of the fixing bolts of variable pitch bearings by adopting a simple and inexpensive combination of engineering parts, thereby reducing the overall cost of the monitoring device.

[0005] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0006] A variable pitch bearing fixing bolt online monitoring device, the variable pitch bearing is installed on the wind turbine blade by fixing bolts and nuts, characterized in that the nut is a ring nut with a through hole, the online monitoring device includes a connecting rope and a sensor device, the sensor device is arranged on the variable pitch bearing, one end of the connecting rope is fixed on the ring nut, and the other end is connected to the sensor device after passing through all the through holes in sequence.

[0007] The utility model provides an online monitoring device for the fixing bolts of a variable pitch bearing. The ring nut with a through hole replaces the traditional nut. The ring nut cooperates with the fixing bolt to fix the variable pitch bearing on the blade of a wind turbine generator. One end of the connecting rope is fixed on the ring nut, and then passes through the through holes on all the ring nuts in sequence. The other end is connected to the sensor device on the variable pitch bearing. When the fixing bolt breaks, the fixing bolt drives the ring nut to fall off from the original fixed position, hangs on the connecting rope, pulls the connecting rope passing through the ring nut, and the connecting rope action controls the sensor device to send a bolt break warning signal to the outside world. After the wind turbine maintenance personnel see the warning signal, they can repair the wind turbine in time. The utility model realizes real-time monitoring of the fracture of the fixing bolts of the variable pitch bearing. The fixing bolts, connecting ropes, and sensors used are all commonly used cheap engineering parts. The ring nut has a simple structure and a production cost that is lower than that of components such as sensors and force-sensitive resistors. The production cost of the online monitoring device for the fixing bolts of the variable pitch bearing is greatly reduced. When applied to the blades of wind turbines with a large number of bolts, the economic advantage is obvious.

[0008] Furthermore, the ring sleeve nut includes a ring groove nut with a groove at one end and a ring sleeve arranged in the groove, and the through hole is arranged on the ring sleeve. The ring groove nut and the ring sleeve together constitute the ring sleeve nut, and one end of the ring groove nut is provided with a groove for placing the ring sleeve, and the ring sleeve is stuck in the groove, providing a through hole for the connection rope to pass smoothly. When the fixing bolt breaks, the ring sleeve and the ring groove nut can be hung on the connection rope, on the one hand, driving the connection rope so that the sensor at the other end of the connection rope sends a warning signal, and on the other hand, preventing the broken bolt and the ring sleeve nut from falling and damaging other parts or injuring maintenance personnel.

[0009] Furthermore, the ring sleeve is a circlip ring sleeve, and the circlip ring sleeve includes a fastening part with a circlip hole and a connecting part, the fastening part is vertically connected to the connecting part, and the through hole is arranged on the connecting part. The fastening part is partially located in the card slot, and partially protrudes from the card slot. The circlip hole is arranged at the position protruding from the card slot, so that the circlip ring sleeve can be installed easily by using circlip pliers; the connecting part is perpendicular to the fastening part and is provided with a through hole, so that the connecting rope can pass through the circlip ring sleeve smoothly and unimpeded without interfering with other parts.

[0010] Furthermore, the ring groove nut and the ring sleeve adopt a clearance fit. The fixing bolts on the wind turbine blades need to be inspected for torque every year. The ring groove nut and the ring sleeve adopt a clearance fit, and the two can rotate relative to each other without affecting the torque inspection work.

[0011] Furthermore, a gasket is provided between the ring sleeve nut and the pitch bearing. Providing the gasket can increase the friction between the gasket and the pitch bearing, and between the ring sleeve nut and the gasket, to prevent the ring sleeve nut from loosening during operation; at the same time, the vibration impact of the pitch bearing on the fixing bolt and the ring sleeve nut during the rotation of the blade is alleviated, providing a shock absorbing effect, and extending the service life of the fixing bolt and the ring sleeve nut.

[0012] Furthermore, the sensor device includes a micro switch connected to the connecting rope, a sensor transmitter, and a mounting bracket for mounting the micro switch and the sensor transmitter, the mounting bracket is arranged on the pitch bearing, and the micro switch is connected to the sensor transmitter by signal. The micro switch and the sensor transmitter are both mounted on the mounting bracket, and when the bolt breaks, the connecting rope is pulled, driving the micro switch connected to the connecting rope to operate, and sending a signal to the sensor transmitter. After receiving the signal, the sensor transmitter transmits a bolt breakage warning signal to notify the maintenance personnel to replace the fixing bolt.

[0013] Furthermore, the sensor device also includes a power detection module, which is connected to the sensor transmitter signal. The power detection module can detect the remaining power in the sensor device, and when the remaining power is insufficient, it sends a signal to the sensor transmitter. After receiving the signal, the sensor transmitter transmits a low power signal to notify the maintenance personnel to replace the battery.

[0014] Furthermore, the mounting bracket is provided with a through hole matched with a fixing bolt. The fixing bolt directly passes through the fixing hole on the mounting bracket to fix the mounting bracket on the pitch bearing, which has a simple structure and does not require other mounting components.

[0015] Furthermore, the mounting bracket is an L-shaped structure including a fixing portion and a mounting portion, the fixing portion is vertically connected to the mounting portion, the mounting portion is in close contact with the pitch bearing, and the fixing hole is arranged on the fixing portion. The L-shaped mounting bracket provides a stable mounting position for the micro switch and the sensor transmitter, and the fixing can be completed by passing the fixing bolt through the fixing hole on the fixing portion, with a simple structure and convenient installation; the mounting portion is in close contact with the pitch bearing, making the mounting structure more stable and taking up less space.

[0016] The utility model also provides an online monitoring system for variable pitch bearing fixing bolts, including the above-mentioned online monitoring device for variable pitch bearing fixing bolts, a signal receiver, a variable pitch PLC and a remote monitoring system for a substation, wherein a plurality of groups of the online monitoring device for variable pitch bearing fixing bolts are arranged on a wind turbine, wherein the plurality of groups of the sensor devices are connected to the signal receivers by signal, the signal receivers are connected to the variable pitch PLCs by signal, and the plurality of groups of the variable pitch PLCs on the wind turbines are connected to the remote monitoring system of the substation by signal.

[0017] The utility model discloses an online monitoring system for fixing bolts of variable pitch bearings, in which a bolt fracture warning signal is sent from a sensor device on a wind turbine blade, and is transmitted to a signal receiver on the wind turbine by wireless communication. The signal receiver aggregates the warning signals on each blade and transmits them to a variable pitch PLC. The variable pitch PLCs on each wind turbine eventually feed back the bolt fracture warning signal to a remote monitoring system of a substation. The staff of the substation arranges maintenance personnel to repair the wind turbine blades with bolt fractures according to the signal content, thereby realizing real-time monitoring, timely detecting bolt fractures, and avoiding major accidents.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] 1. The ring nut has a simple structure and low production cost; other components of the system are common engineering components with low prices. The overall cost of the monitoring system is low and the economy is good.

[0020] 2. The device has high safety. After the fixing bolt breaks, it will be hung on the connecting rope to prevent the broken bolt from damaging other components of the variable pitch system and also prevent the broken bolt from falling from the wind turbine and injuring maintenance personnel.

[0021] 3. Real-time monitoring of blade fixing bolts is realized to detect bolt breakage in time, thus avoiding major accidents such as the spread of breakage and blade falling. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present utility model. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0023] Figure 1 A schematic diagram of an online monitoring device for fixing bolts of a pitch bearing provided by the utility model;

[0024] Figure 2 A schematic diagram of a ring groove nut provided by the utility model;

[0025] Figure 3 A schematic diagram of a circlip type ring sleeve provided by the utility model;

[0026] Figure 4 Assembly diagram of the ring sleeve nut and the fixing bolt provided by the utility model;

[0027] Figure 5 A schematic diagram of a fixing bracket provided by the utility model;

[0028] Figure 6 The electrical schematic diagram of the online monitoring system for the fixed bolts of the variable pitch bearing provided by the utility model;

[0029] Description of reference numerals:

[0030] 1. Wind turbine blade; 2. Pitch bearing; 3. Fixing bolt; 4. Sleeve nut; 41. Groove nut; 411. Slot; 42. Circlip type sleeve; 421. Circlip hole; 422. Fastening part; 423. Through hole; 424. Connecting part; 5. Connecting rope; 6. Sensor device; 61. Micro switch; 62. Sensor transmitter; 63. Mounting bracket; 631. Fixing part; 632. Mounting part; 633. Fixing hole; 7. Gasket. DETAILED DESCRIPTION

[0031] The utility model is further described below in conjunction with specific implementation methods. The drawings are only used for exemplary descriptions, and are only schematic diagrams, not actual pictures, and cannot be understood as limitations on this patent; in order to better illustrate the embodiments of the utility model, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0032] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0033] Embodiment 1

[0034] like Figure 1As shown, the present embodiment provides an online monitoring device for a variable pitch bearing fixing bolt, comprising a ring sleeve nut 4 provided with a through hole 423, a connecting rope 5 and a sensor device 6, a variable pitch bearing 2 and a sensor device 6 are provided on a wind turbine blade 1, a plurality of groups of evenly distributed fixing bolts 3 are provided on the variable pitch bearing 2, the ring sleeve nut 4 is threadedly connected to the fixing bolts 3, one end of the connecting rope 5 is fixed on the ring sleeve nut 4, and the other end sequentially passes through all the through holes 423 and is connected to the sensor device 6.

[0035] During installation, the sensor device 6 is in an untriggered state. One end of the connecting rope 5 is fixed on the sensor device 6, and then it is sequentially passed through the through holes 423 on all the ring nuts 4. When it reaches the last ring nut 4, it is slightly tightened so that the connecting rope 5 is not loose. It should not be tightened to the state of triggering the sensor device 6. Finally, the connecting rope 5 is fixed on the through hole 423 of the last ring nut 4. When the fixing bolt 3 is not broken, the slackness of the connecting rope 5 is normal, and the sensor device 6 is in an untriggered state; when a fixing bolt 3 is broken, during the rotation of the blade, the broken fixing bolt 3 and the ring nut 4 fall off from the pitch bearing 2, and the connecting rope 5 passing through the ring nut 4 is pulled, triggering the sensor device 6, and the sensor device 6 feeds back the bolt breakage signal to the outside world. At present, the number of bolts on a wind turbine is usually more than 100. The conventional fixing bolt 3 fracture detection system requires the installation of sensors or force-sensitive resistors on each fixing bolt 3, and the overall cost of the monitoring system remains high. This embodiment achieves real-time monitoring of the fracture of the variable pitch bearing fixing bolts through a combination of commonly used inexpensive engineering parts. The overall cost of the monitoring system is low, and is suitable for use in work environments with a large number of bolts.

[0036] like Figure 2 , Figure 3As shown, the ring sleeve nut 4 of this embodiment includes a ring groove nut 41 with a groove 411 at one end and a ring sleeve arranged in the groove 411, and the through hole 423 is arranged on the ring sleeve. Preferably, the ring sleeve in this embodiment is a circlip ring sleeve 42, and the circlip ring sleeve 42 includes a fastening portion 422 with a circlip hole 421 and a connecting portion 424 with a through hole 423, and the fastening portion 422 is vertically connected to the connecting portion 424. The ring groove nut 41 and the circlip ring sleeve 42 together constitute the ring sleeve nut 4, and the ring groove nut 41 is provided with a groove 411 at one end for placing the circlip ring sleeve 42, and the fastening portion 422 is partially located in the groove 411 and partially protrudes from the groove 411, and the portion protruding from the groove 411 is vertically connected to the connecting portion 424, and is provided with a circlip hole 421. The circlip ring 42 can be installed on the groove 411 of the ring groove nut 41 by using circlip pliers and the circlip hole 421. The installation operation is simple and saves installation time. The through hole 423 is set on the connecting part 424 protruding from the groove 411, which is convenient for the connection rope 5 to pass smoothly and connect all the ring sleeve nuts 4 in series. The ring groove nut 41 and the circlip ring 42 have a simple structure, are easy to process, have low production cost, and reduce the overall cost of the device.

[0037] In this embodiment, the ring groove nut 41 and the circlip ring sleeve 42 are clearance-matched, and the ring groove nut 41 and the circlip ring sleeve 42 can rotate relative to each other. To ensure the reliability of the connection, the fixing bolts 3 on the wind turbine blades 1 need to be inspected for torque by using a hydraulic wrench for more than 10% every year. In order to avoid damaging the sensor, the bolts of the traditional phased array sensor need to be removed for inspection, which is inconvenient to operate. The fixing bolts 3 in this embodiment can be directly inspected for torque on the wind turbine, and the ring groove nut 41 and the circlip ring sleeve 42 can rotate, which will not affect the torque inspection and save working time.

[0038] like Figure 4 As shown, a gasket 7 is provided between the ring sleeve nut 4 and the pitch bearing 2 in this embodiment, and the surface of the gasket 7 is set to be a frosted surface. The gasket 7 provides a shock-absorbing effect, which can alleviate the impact on the fixing bolt 3 and the ring sleeve nut 4 during the rotation of the wind turbine blade 1, and extend the service life of the parts. The surfaces of both sides of the gasket 7 are frosted, which increases the friction between the gasket 7 and the ring sleeve nut 4 and between the gasket 7 and the pitch bearing 2, prevents the ring sleeve nut 4 from loosening during the working process, and improves the safety of the online monitoring device of the fixing bolt 3 of the pitch bearing 2.

[0039] The connection rope 5 of this embodiment has a smooth surface and a high tensile strength. The connection rope 5 of this embodiment can be made of steel wire or plastic rope, and its surface is controlled to be smooth and its diameter is smaller than the diameter of the through hole 423, so as to facilitate passing through the ring nut 4. When the fixing bolt 3 is broken, the connection rope 5 has a certain strength, and the broken fixing bolt 3 and the replacement nut can be hung on the pitch bearing 2, so as to prevent the broken fixing bolt 3 from damaging other components on the pitch system, and also prevent the fixing bolt 3 from falling from the wind turbine and injuring maintenance personnel, thereby improving the safety of the device.

[0040] Embodiment 2

[0041] like Figure 1 As shown, this embodiment is similar to the second embodiment, except that the sensor device 6 of this embodiment includes a micro switch 61 connected to the connecting rope 5, a sensor transmitter 62, and a mounting bracket 63 for mounting the micro switch 61 and the sensor transmitter 62. The mounting bracket 63 is arranged on the pitch bearing 2, and the micro switch 61 controls the sensor transmitter 62. The micro switch 61 can be a commonly used long-rod micro switch 61. The switch long rod on the micro switch 61 is connected to the connecting rope 5. When the fixing bolt 3 is not broken, the connecting rope 5 does not move; when the fixing bolt 3 is broken, the connecting rope 5 is pulled, the switch long rod is pressed, and the micro switch 61 is driven to move and transmit a signal to the sensor transmitter. After receiving the signal from the micro switch 61, the sensor transmitter 62 transmits the bolt breakage warning signal to the outside by wireless communication.

[0042] The sensor transmitter 62 of this embodiment is provided with a power detection module. The power detection module can detect the remaining power in the sensor device 6. When the remaining power is insufficient, the power detection module transmits a signal to the sensor transmitter 62, and the sensor transmitter 62 transmits the insufficient power signal to the outside by wireless communication to notify the maintenance personnel to replace the battery.

[0043] like Figure 5 As shown, in this embodiment, the mounting bracket 63 is an L-shaped structure including a fixing portion 631 and a mounting portion 632. The mounting bracket 63 is provided with a fixing hole 633 matched with the fixing bolt 3. The fixing portion 631 is vertically connected with the mounting portion 632. The mounting portion 632 is in close contact with the pitch bearing 2. The fixing hole 633 is arranged on the fixing portion 631. The fixing bolt 3 directly passes through the fixing hole 633, and the fixing bracket is fixed to the pitch bearing 2 as a whole through the ring nut 4. No gasket 7 is required to be arranged at the installation position; the mounting portion 7 is in close contact with the pitch bearing 2, and the micro switch 61 and the sensor transmitter 62 are both arranged on the mounting portion 7. Only an L-shaped mounting bracket 63 is required to cooperate with the original fixing bolt 3 and the ring nut 4 to complete the installation of the micro switch 61 and the sensor transmitter 62. No other installation components are required, and the structure is simple and easy to install.

[0044] Embodiment 3

[0045] like Figure 6 As shown, this embodiment is an embodiment of an online monitoring system for variable pitch bearing fixing bolts. This embodiment includes the above-mentioned online monitoring device for variable pitch bearing fixing bolts, a signal receiver, a variable pitch PLC and a remote monitoring system for a booster station. The online monitoring device for variable pitch bearing fixing bolts is provided with multiple groups on the wind turbine. Multiple groups of sensor devices 6 are connected to the signal receiver by signal, and the signal receiver is connected to the variable pitch PLC by signal. The variable pitch PLCs on multiple groups of wind turbines are connected to the remote monitoring system of the booster station by signal. The wind turbine is provided with multiple groups of blades, and each blade is provided with an online monitoring device for variable pitch bearing fixing bolts. When the bolts on the blades are broken, the sensor device 6 in the online detection device transmits a bolt breakage warning signal to the signal receiver provided on the wind turbine. The signal receiver summarizes the bolt breakage on each blade, and then transmits the bolt breakage warning signal to the variable pitch PLC. The variable pitch PLCs on each group of wind turbines transmit the bolt breakage warning signal to the remote monitoring system of the booster station, and promptly notify the maintenance personnel, thereby realizing real-time monitoring of the blade fixing bolts, promptly discovering the bolt breakage, and avoiding major accidents such as the spread of the breakage and the falling of the blades.

[0046] In the specific contents of the above-mentioned specific implementation methods, the various technical features can be combined in any non-contradictory manner. In order to make the description concise, not all possible combinations of the above-mentioned technical features are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] Obviously, the above embodiments of the utility model are only examples for clearly explaining the utility model, and are not intended to limit the implementation methods of the utility model. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the utility model should be included in the protection scope of the claims of the utility model.

Claims

1. An online monitoring device for a variable pitch bearing fixing bolt, wherein the variable pitch bearing (2) is mounted on a wind turbine blade (1) through a plurality of fixing bolts (3) and nuts arranged evenly in a circular shape, characterized in that: The nut is a ring nut (4) provided with a through hole (423), the online monitoring device comprises a connecting rope (5) and a sensor device (6), the sensor device (6) is arranged on the variable pitch bearing (2), one end of the connecting rope (5) is fixed on the ring nut (4), and the other end is connected to the sensor device (6) after passing through all the through holes (423) in sequence.

2. The online monitoring device for the fixing bolts of a pitch bearing according to claim 1, characterized in that: The ring sleeve nut (4) comprises a ring groove nut (41) having a clamping groove (411) at one end and a ring sleeve arranged in the clamping groove (411), and the through hole (423) is arranged on the ring sleeve.

3. The online monitoring device for the fixing bolts of a pitch bearing according to claim 2 is characterized in that: The ring sleeve is a spring-type ring sleeve (42), and the spring-type ring sleeve (42) comprises a fastening portion (422) provided with a spring hole (421) and a connecting portion (424), the fastening portion (422) and the connecting portion (424) are vertically connected, and the through hole (423) is provided on the connecting portion (424).

4. The online monitoring device for the fixing bolts of a pitch bearing according to claim 2, characterized in that: The annular groove nut (41) and the annular sleeve are clearance-fitted.

5. The online monitoring device for the fixing bolts of a pitch bearing according to claim 2, characterized in that: A gasket (7) is provided between the ring sleeve nut (4) and the pitch bearing (2).

6. An online monitoring device for pitch bearing fixing bolts according to any one of claims 1 to 5, characterized in that: The sensor device (6) comprises a micro switch (61) connected to the connecting rope (5), a sensor transmitter (62), and a mounting bracket (63) for mounting the micro switch (61) and the sensor transmitter (62); the mounting bracket (63) is arranged on the pitch bearing (2); and the micro switch (61) is signal-connected to the sensor transmitter (62).

7. The online monitoring device for the fixing bolts of a pitch bearing according to claim 6, characterized in that: The sensor device (6) also includes a power detection module, and the power detection module is connected to the sensor transmitter (62) by signal.

8. The online monitoring device for the fixing bolts of a pitch bearing according to claim 6, characterized in that: The mounting bracket (63) is provided with a fixing hole (633) that cooperates with the fixing bolt (3).

9. The online monitoring device for the fixing bolts of a pitch bearing according to claim 8, characterized in that: The mounting bracket (63) is an L-shaped structure including a fixing portion (631) and a mounting portion (632), the fixing portion (631) and the mounting portion (632) are vertically connected, the mounting portion (632) is in close contact with the pitch bearing (2), and the fixing hole (633) is arranged on the fixing portion (631).

10. An online monitoring system for pitch bearing fixing bolts, characterized in that: It comprises an online monitoring device for variable pitch bearing fixing bolts, a signal receiver, a variable pitch PLC and a remote monitoring system for a substation as described in any one of claims 1 to 9, wherein a plurality of the online monitoring devices for variable pitch bearing fixing bolts are arranged on a wind turbine, a plurality of the sensor devices (6) are connected to the signal receiver for signal connection, the signal receiver is connected to the variable pitch PLC for signal connection, and a plurality of the variable pitch PLCs on the wind turbine are connected to the remote monitoring system for a substation for signal connection.

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