Method and equipment for monitoring looseness of double nuts in narrow space

Abstract

The invention discloses a narrow space double-nut looseness monitoring method and device, and relates to the technical field of fans, the narrow space double-nut looseness monitoring device comprises a mounting base, an adjusting frame, a sensor module, bolts, nuts and a flange plate upper end face, the mounting base is fixedly mounted on the flange plate upper end face, and the adjusting frame is fixedly connected with the mounting base through screws; the sensor is high in measurement precision, easy to install, convenient and fast to maintain, capable of effectively reducing cost and suitable for narrow space monitoring, the sensor is provided with the two complementary connectors, the looseness detection requirement of a high-strength connecting bolt set of a wind turbine generator tower drum or a hub distributed annularly is met, the wiring length is reduced, the sensor is divided into two assemblies, and the cost is reduced. For the maintenance of the loosened high-strength connecting bolt, when the situation that the bolt is loosened is found through the monitoring of the sensor, the operation space can be cleared by only shifting the adjusting frame, and after the bolt is screwed, the bolt loosening situation can be continuously monitored by releasing the adjusting frame.

Description

Technical Field

[0001] This invention relates to the field of wind turbine technology, specifically a method and device for monitoring the loosening of double nuts in a confined space. Background Technology

[0002] The space at the flange connection of the wind turbine blade is very narrow. Sometimes the minimum space between the upper surface of the bolt and the obstruction is less than one centimeter (defined as narrow space: the distance between the upper surface of the bolt and the obstruction is less than 1 centimeter). Traditional bolt loosening monitoring methods require installing sensors on the upper surface of the bolt. Once the blade is hoisted, it is not practical to install sensors on the bolt to monitor bolt loosening. For this special working condition, there is no particularly effective method other than manual inspection.

[0003] Wind turbines contain tower flange bolts and blade flange bolts. Blade flange bolts are more likely to become loose or break than tower flange bolts. Therefore, monitoring for loose blade flange bolts is essential. If bolts break or flanges become misaligned, the replacement cost is extremely high. Therefore, there is an urgent need for a monitoring method that is easy to operate, highly accurate, and inexpensive for this application scenario.

[0004] 1. Most products on the market that use magnetic encoders to monitor bolt loosening work by using two modules. Module 1 is a radially magnetized magnet fixed to the bolt, and Module 2 is an accessory containing a magnetic encoder, which is fixed to the nut. When the nut loosens, it causes the magnetic encoder chip to generate a change in angle relative to the original magnetic field. The change in angle reflects the loosening of the bolt, thus realizing the monitoring of bolt loosening. The disadvantage is that the fixing of Module 1 and Module 2 requires a certain amount of space, at least 2 cm. Even if the required space is compressed, it is not convenient to install in a small space. Moreover, when the nut loosens to a certain angle, if the distance between the magnetic encoder and the magnet is greater than 3 mm, the measurement will deviate as the distance increases.

[0005] 2. Some products on the market use proximity switches to detect bolt loosening. These also consist of two modules: module 1 is a metal rod fixed to the side of the nut, and module 2 is a proximity switch. When the metal rod rotates with the nut to the vicinity of the proximity switch, the proximity switch issues an alarm. The disadvantages are that the metal rod needs to rotate a certain distance to reach the proximity switch, and the bolt will not generate an alarm if it is loose within a certain angle. In addition, the proximity switch can only provide one alarm signal and cannot provide information about the actual situation of the bolt loosening. The metal rod needs to be fixed to the nut, and it needs to be removed later when tightening the bolt, requiring secondary construction.

[0006] 3. Most monitoring solutions on the market are one-to-one tests, meaning one device can only monitor one bolt, making it impossible for a single sensor to monitor multiple bolts simultaneously over a long period. Summary of the Invention

[0007] The purpose of this invention is to provide a method and device for monitoring the loosening of two nuts in a confined space. The sensor directly monitors the rotation angle of the nut relative to the flange. One sensor can monitor the loosening of two nuts simultaneously. As the loosening angle of the nuts changes, the sensor supports self-correction of the measurement angle to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A monitoring device for double-nut loosening in confined spaces includes a mounting base, an adjusting frame, a sensor module, bolts and nuts, and an upper flange face. The mounting base is fixedly mounted on the upper flange face. The adjusting frame is fixedly connected to the mounting base by screws. The adjusting frame includes a pin, a left adjusting frame, a right adjusting frame, an adjusting torsion spring, a magnetic gear, a connecting rod, a magnetic gear mounting plate, a first rack, and a second rack. One end of the left adjusting frame and one end of the right adjusting frame are connected by a pin, and an adjusting torsion spring is sleeved on the pin. One end of the connecting rod is fixedly connected to the pin, and the other end of the connecting rod is mounted with a magnetic gear mounting plate. Two magnetic gears are mounted on the lower surface of the magnetic gear mounting plate. The first rack and the second rack are respectively fixed on the left and right adjusting frames and mesh with the two magnetic gears. The sensor module is fixedly connected to the adjusting frame and is mounted on the upper part of the adjusting frame. The sensor module includes a sensor body and a sensor housing. The sensor housing is mounted on the upper part of the magnetic gear mounting plate, and two sensor bodies are mounted on the sensor housing.

[0010] As a further aspect of the present invention: two radially magnetized magnets are embedded inside the magnetic gear, and the magnets are placed horizontally.

[0011] As a further embodiment of the present invention: the two sensor bodies are located directly above the coaxial center of two radially magnetized magnets.

[0012] As a further embodiment of the present invention: the two sensor bodies are connected in series via a 485 bus.

[0013] As a further embodiment of the present invention: the mounting base and the adjusting bracket are both disposed between two adjacent bolts and nuts.

[0014] As a further aspect of the present invention: the sensor body inside the sensor housing is a magnetic field sensor.

[0015] As a further aspect of the present invention: a DIP switch is installed on the mounting base, and the DIP switch is electrically connected to the sensor module.

[0016] A method for monitoring the loosening of double nuts in a confined space, the steps of which are as follows;

[0017] S1. When the bolts and nuts become loose, the adjusting bracket will rotate and reciprocate due to the loosening of the adjusting torsion spring installed at the pin.

[0018] S2. The rack on the adjusting frame will drive the magnetic gear and the embedded magnet to rotate, converting the linear motion of the precision rack into the rotational motion of the precision gear.

[0019] S3. The two sensor bodies on the PCB board inside the sensor module are located directly above the coaxial center of the two magnets, which can measure the direction of the magnetic field. The change in the direction of the magnetic field is converted into the change in the rotation angle of the nut through calculation. By measuring the change in the direction of the magnetic field, the loosening angle of the nut can be monitored.

[0020] The present invention enables the sensor to self-correct the measurement angle as the nut loosening angle changes. The nut loosening sensor supports self-correction of the measurement angle, and the method steps are as follows;

[0021] S1. Due to the mechanical structure characteristics of the sensor, the nut loosening angle and the angle monitored by the sensor change periodically.

[0022] S2. Whenever the nut loosens by 1 / 6 turn, the rotation angle of the magnet detected by the sensor will undergo a cycle change.

[0023] S3. Based on this characteristic, whenever the sensor analyzes and obtains information about the magnet returning to its original position, it can be used as a calibration signal with a 60° change.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. Existing products on the market generally require a large space on the top of the bolt and are composed of multiple parts; at least one component is installed on the bolt. Tightening the bolt later requires disassembling the equipment, resulting in secondary construction issues. In actual field situations, the gap at the top of the bolt is often narrow, leaving no installation space or operating space. This invention does not occupy the space on the upper surface of the bolt, nor does it require any operations that damage the existing structure, such as pasting or drilling into the nut. Instead, it integrates the entire monitoring system into a single, independent structure, installed between two nuts. The sensor structure is softly connected to the nuts via an adjustable torsion spring. When tightening the nuts, simply moving one side of the adjustment bracket creates operating space without disassembling the sensor.

[0026] 2. Existing products on the market require one set of equipment to monitor one group of bolts. Two groups of bolts require two sets of equipment, and the detection equipment consists of both mechanical and hardware components. The difference between this invention and existing products is that one set of mechanical and hardware components can simultaneously monitor two bolts, using a single monitoring device. The PCB board of this invention only requires a CPU, power supply, communication module, and two sensing chips; while existing products require two CPUs, two power supplies, two communication modules, and two sensing chips to monitor two bolts. Therefore, this invention significantly reduces monitoring costs compared to existing products on the market.

[0027] 3. When encountering special circumstances that require disassembly of the sensor, this invention is easier to disassemble than other products; simply remove the adjustment bracket from the mounting base.

[0028] 4. The sensor of this invention can self-correct the measurement angle as the nut loosens, so there is no need to worry about measurement errors after the nut has loosened to a certain angle.

[0029] 5. This invention can reduce the cost of bolt monitoring, facilitate installation, reduce the workload of sensor installation and disassembly, and has greater adaptability. Attached Figure Description

[0030] Figure 1 This is an installation effect diagram of the present invention.

[0031] Figure 2 The structural composition of the present invention Figure 1 .

[0032] Figure 3 The structural composition of the present invention Figure 2 .

[0033] Figure 4 This is a schematic diagram of the overall structure of the adjustment frame of the present invention.

[0034] Figure 5 This is a schematic diagram of the overall structure of the sensor module of the present invention.

[0035] 1. Mounting base; 2. Adjustment bracket; 201. Pin; 202. Left adjustment bracket; 203. Right adjustment bracket; 204. Adjustment torsion spring; 205. Magnetic gear; 206. Connecting rod; 207. Magnetic gear mounting plate; 208. First rack; 209. Second rack; 3. Sensor module; 301. Sensor body; 302. Sensor housing; 4. Bolts and nuts; 5. Upper end face of flange; 6. DIP switch. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Please see Figure 1-4 In this embodiment of the invention, a monitoring device for double-nut loosening in a confined space includes a mounting base 1, an adjusting frame 2, a sensor module 3, bolts and nuts 4, and an upper end face 5 of a flange. The mounting base 1 is fixedly mounted on the upper end face 5 of the flange. The adjusting frame 2 is fixedly connected to the mounting base 1 by screws. Both the mounting base 1 and the adjusting frame 2 are located between two adjacent bolts and nuts 4. The adjusting frame 2 includes a pin 201, a left adjusting frame 202, a right adjusting frame 203, an adjusting torsion spring 204, a magnetic gear 205, a connecting rod 206, a magnetic gear mounting plate 207, and a first rack 206. 8. The second rack 209, one end of the left adjustment frame 202 and one end of the right adjustment frame 203 are connected by a pin 201. An adjusting torsion spring 204 is sleeved on the pin 201. One end of the connecting rod 206 is fixedly connected to the pin 201. The other end of the connecting rod 206 is equipped with a magnetic gear mounting plate 207. Two magnetic gears 205 are installed on the lower plate of the magnetic gear mounting plate 207. The first rack 208 and the second rack 209 are fixed on the left adjustment frame 202 and the right adjustment frame 203 respectively. The first rack 208 and the second rack 209 mesh with the two magnetic gears 205 respectively.

[0038] Please see Figure 1-3 and Figure 5 The sensor module 3 is fixedly connected to the adjustment frame 2. The sensor module 3 is installed on the upper part of the adjustment frame 2. The sensor module 3 includes a sensor body 301 and a sensor housing 302. The sensor housing 302 is installed on the upper part of the magnet gear mounting plate 207. Two sensor bodies 301 are installed on the sensor housing 302.

[0039] The assembly process of this invention is described as follows: Place the adjusting torsion spring 204 into the middle of the mounting hole of the right adjusting bracket 203, fit the left adjusting bracket 202 onto the right adjusting bracket 203, and screw the pin 201 into the screw mounting through hole provided on the mounting bracket. Then, screw the magnetic gear 205 into the mounting hole to achieve precise meshing between the mounting bracket rack and the gear. Finally, install the sensor module 3 on the adjusting bracket 2, and then install this component on the mounting base 1. After the sensor assembly is completed, loosen the bolts and fix the sensor to a suitable position on the upper end face 5 of the flange, ensuring a secure fixation.

[0040] Please see Figure 2 and Figure 5Two radially magnetized magnets are embedded inside the magnetic gear 205. The magnets are placed horizontally. The two sensor bodies 301 are located directly above the coaxial center of the two radially magnetized magnets, which can measure the direction of the magnetic field. The change in the direction of the magnetic field is converted into the change in the rotation angle of the nut through calculation. By measuring the change in the direction of the magnetic field, the loosening angle of the nut can be monitored. The two sensor bodies 301 are connected in series via a 485 bus. The sensor body 301 inside the sensor housing 302 is a magnetic field sensor.

[0041] Please see Figure 1 A DIP switch 6 is installed on the mounting base 1. The DIP switch 6 is electrically connected to the sensor module 3. To avoid data jumps caused by secondary installation, the sensor is equipped with a DIP switch 6. Before disassembly, the DIP switch 6 is pressed down. After secondary installation, the DIP switch 6 is pressed down again. The DIP switch 6 is a known product. The sensor will match the current angle with the angle before it was pressed down. After reinstallation, it will still transmit the original angle. This design can avoid the impact of multiple initializations on the continuity of long-term observation data.

[0042] The sensor of this invention features high measurement accuracy, simple installation, convenient maintenance, and effective cost reduction. It is suitable for monitoring in confined spaces. The sensor has two complementary connectors to meet the loosening detection needs of high-strength connecting bolt groups in a ring-shaped distribution of wind turbine towers or hubs, reducing wiring length. The sensor consists of two components. For the maintenance of loose high-strength connecting bolts, when the sensor detects a loose bolt, simply adjust the adjustment bracket 2 to create operating space. After tightening, releasing the adjustment bracket 2 allows for continued monitoring of bolt loosening. The sensor can adapt to bolt groups with limited installation space.

[0043] A method for monitoring the loosening of double nuts in a confined space, the steps of which are as follows;

[0044] S1. When the bolt and nut 4 loosen, the adjusting bracket 2 will rotate and reciprocate due to the adjustment torsion spring 204 installed at the pin 201 as the bolt and nut 4 loosens.

[0045] S2, the rack on the adjusting frame 2 will drive the magnetic gear 205 and the embedded magnet to rotate, converting the linear motion of the precision rack into the rotational motion of the precision gear;

[0046] S3. The two sensor bodies 301 on the PCB board inside the sensor module 3 are located directly above the coaxial center of the two magnets, which can measure the direction of the magnetic field. The change in the direction of the magnetic field is converted into the change in the rotation angle of the nut through calculation. By measuring the change in the direction of the magnetic field, the loosening angle of the nut can be monitored.

[0047] It should be noted that the adjusting torsion spring 204 of the adjusting frame 2 can be replaced with a spring or a leaf spring, the fixing method of the adjusting frame 2 can be replaced with a snap ring, a buckle, or a metal strap, the contact end between the adjusting frame 2 and the nut can be replaced with a wheel type, and the rack and pinion structure of the adjusting frame 2 can be replaced with a spring or a leaf spring.

[0048] The main structural components of the sensor are made of plastic, which can withstand harsh environmental humidity and salt spray, ensuring that the sensor works stably in various environments and has a long service life.

[0049] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A monitoring device for double-nut loosening in a confined space, comprising a mounting base (1), an adjustment frame (2), a sensor module (3), bolts and nuts (4), and an upper flange face (5), characterized in that: The mounting base (1) is fixedly mounted on the upper end face (5) of the flange. The adjusting bracket (2) is fixedly connected to the mounting base (1) by screws. The adjusting bracket (2) includes a pin (201), a left adjusting bracket (202), a right adjusting bracket (203), an adjusting torsion spring (204), a magnetic gear (205), a connecting rod (206), a magnetic gear mounting plate (207), a first rack (208), and a second rack (209). One end of the left adjusting bracket (202) and one end of the right adjusting bracket (203) are connected by a pin (201). An adjusting torsion spring (204) is sleeved on the pin (201). One end of the connecting rod (206) is fixedly connected to the pin (201). The other end of the connecting rod (206) is equipped with a magnetic gear mounting plate (208). 7) Two magnetic gears (205) are installed on the lower plate surface of the magnetic gear mounting plate (207). The first rack (208) and the second rack (209) are fixed on the left adjustment frame (202) and the right adjustment frame (203) respectively. The first rack (208) and the second rack (209) mesh with the two magnetic gears (205) respectively. The sensor module (3) is fixedly connected to the adjustment frame (2). The sensor module (3) is installed on the upper part of the adjustment frame (2). The sensor module (3) includes a sensor body (301) and a sensor housing (302). The sensor housing (302) is installed on the upper part of the magnetic gear mounting plate (207). Two sensor bodies (301) are installed on the sensor housing (302).

2. The monitoring device for double nut loosening in a confined space according to claim 1, characterized in that: The magnetic gear (205) has two radially magnetized magnets embedded inside, and the magnets are placed horizontally.

3. The monitoring device for double nut loosening in a confined space according to claim 1, characterized in that: The two sensor bodies (301) are located directly above the coaxial center of two radially magnetized magnets.

4. The monitoring device for double nut loosening in a confined space according to claim 1, characterized in that: The two sensor bodies (301) are connected in series via a 485 bus.

5. The monitoring device for double nut loosening in a confined space according to claim 1, characterized in that: The mounting base (1) and the adjusting bracket (2) are both located between two adjacent bolts and nuts (4).

6. The monitoring device for double nut loosening in a confined space according to claim 1, characterized in that: The sensor body (301) inside the sensor housing (302) is a magnetic field sensor.

7. The monitoring device for double nut loosening in a confined space according to claim 1, characterized in that: A DIP switch (6) is installed on the mounting base (1), and the DIP switch (6) is electrically connected to the sensor module (3).

8. A method for monitoring the loosening of double nuts in a confined space, characterized in that: The method and steps are as follows; S1. When the bolt and nut (4) loosen, the adjusting bracket (2) will rotate and reciprocate due to the adjustment torsion spring (204) installed at the pin (201) as the bolt and nut (4) loosen. S2. The rack on the adjusting frame (2) will drive the magnetic gear (205) and the embedded magnet to rotate, converting the linear motion of the precision rack into the rotational motion of the precision gear. S3. The two sensor bodies (301) on the PCB board inside the sensor module (3) are located directly above the coaxial center of the two magnets. They can measure the direction of the magnetic field. The change in the direction of the magnetic field is converted into the change in the rotation angle of the nut by calculation. The loosening angle of the nut can be monitored by measuring the change in the direction of the magnetic field.

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