An improved bolt loosening monitoring device

Abstract

This invention discloses an improved bolt loosening monitoring device, comprising: a bolt cap fitted onto the end of the bolt's threaded portion; a magnet disposed within the top surface of the bolt cap; a nut sleeve fitted onto the outer circumferential surface of a nut mounted on the threaded portion; a nut rotating sleeve fitted onto the end of the nut sleeve and located on the outer circumferential side of the bolt cap; a rotating ring disposed within the end of the nut rotating sleeve and above the nut sleeve; and a PCB board disposed within the rotating ring and above the magnet, the PCB board integrating a magnetic induction chip for collecting changes in the magnetic field of the magnet. This invention achieves an ultra-thin design, adapting to confined spaces and solving the installation problem of inconsistent bolt protrusion heights from the nut.

Description

Technical Field

[0001] This invention relates to the field of bolt loosening monitoring technology, and in particular to an improved bolt loosening monitoring device. Background Technology

[0002] Bolt loosening is a common failure mode in the blade root connection of wind turbine generators, especially under long-term alternating loads and vibration environments, where a decrease in preload will directly threaten the safety of the entire unit. Therefore, real-time monitoring of blade root bolt loosening is of great significance.

[0003] Currently, various bolt loosening detection technologies have been proposed, such as monitoring preload changes using strain or piezoelectric sensors, identifying loosening based on the nonlinear vibration characteristics of the connection system, and capturing elastic wave release during the loosening process using acoustic emission signals. These methods can identify loosening under specific conditions, but they generally suffer from the following shortcomings: 1. The detection system is complex, cumbersome to operate, and inefficient, making it difficult to meet the needs of rapid on-site deployment and continuous monitoring; 2. The sensor is too large to fit into the extremely narrow installation space of the wind turbine blade root bolts; 3. Due to manufacturing and assembly tolerances, the height of the screw ends protruding from the nut surface is inconsistent. Existing sensors often require fixed installation height or contact conditions and lack height adjustment capability, which leads to installation difficulties or even inability to use them. 4. Most methods can only perform single or intermittent detection and cannot output continuous numerical changes in bolt loosening in real time.

[0004] Therefore, through beneficial exploration and research, the applicant has found a solution to the above problems, and the technical solution to be introduced below is the result of this research. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an improved bolt loosening monitoring device that is compact in structure, adaptable to narrow spaces, adjustable in installation height to match different bolt protrusion lengths, and can provide real-time feedback of loosening values, in order to address the shortcomings of the prior art.

[0006] The technical problem to be solved by this invention can be achieved by the following technical solution: An improved bolt loosening monitoring device includes: A bolt cap fitted onto the end of the bolt's threaded portion; A magnet is disposed within the top surface of the bolt cap; A nut sleeve fitted onto the outer circumferential surface of a nut mounted on a screw section; A nut rotating sleeve that is fitted onto the end of the nut sleeve and located on the outer periphery of the bolt cap; A rotating ring, wherein the rotating ring is disposed within the end of the nut rotating sleeve and located above the nut sleeve; and A PCB board is disposed inside the rotating ring and above the magnet, and a magnetic induction chip for collecting changes in the magnetic field of the magnet is integrated inside the PCB board.

[0007] In a preferred embodiment of the present invention, a magnet mounting groove is provided on the top surface of the bolt cap, the magnet is installed in the magnet mounting groove of the bolt cap, and the upper end surface of the magnet is flush with the top surface of the bolt cap.

[0008] In a preferred embodiment of the present invention, an outer annular flange is formed on the top surface of the bolt cap, and an inner annular flange located on the inner periphery of the outer annular flange is formed on the end face of the rotating ring facing the bolt cap. A bearing is provided on the top surface of the bolt cap between the outer annular flange and the inner annular flange.

[0009] In a preferred embodiment of the present invention, a PCB board mounting cavity is formed inside the rotating ring, and the PCB board is mounted inside the PCB board mounting cavity.

[0010] In a preferred embodiment of the present invention, a plurality of pot magnet mounting grooves are provided circumferentially spaced on the outer peripheral surface of the nut sleeve, and a pot magnet is embedded in each pot magnet mounting groove.

[0011] In a preferred embodiment of the present invention, at least one adapter sleeve for adjusting the height is provided between the nut sleeve and the nut rotating sleeve.

[0012] In a preferred embodiment of the present invention, the bolt cap and the bolt shank, the nut sleeve and the adapter sleeve, and the adapter sleeve and the nut rotating sleeve are detachably connected by threads.

[0013] In a preferred embodiment of the present invention, a cable connector and a data connection cable are further included, one end of the data connection cable being connected to the cable connector, and the other end passing through the rotating ring and being connected to the PCB board.

[0014] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: 1. Achieved an ultra-thin design, adaptable to confined spaces. Addressing the extremely limited space at the head of the wind turbine blade root bolts, this invention controls the height of the protruding screw of the sensing and monitoring device to only 8 millimeters, far lower than existing products, successfully solving the bottleneck of traditional sensors being too large to install.

[0015] 2. This invention solves the installation problem of inconsistent screw protrusion heights onto the nut. An adjustable-length adapter sleeve is incorporated into the nut sleeve assembly, allowing for height adjustment via a threaded connection. When different bolts have varying screw protrusion lengths, the adapter sleeve can be added or removed to ensure accurate installation of the nut sleeve onto the nut, significantly improving the device's adaptability to different bolt specifications on-site.

[0016] 3. Real-time angle monitoring and numerical feedback of bolt loosening are achieved. This invention reflects the loosening state by detecting the relative rotation angle between the bolt and nut. Changes in the bolt angle are uploaded to the monitoring system in real time, and users can continuously view the loosening values. When the value reaches a preset critical value, the system automatically alarms, ensuring that pre-tightening maintenance is performed as soon as bolt loosening occurs, effectively preventing the accident from escalating.

[0017] 4. Simple and quick on-site construction. This invention adopts a split-type modular structure. First, the bolt sleeve assembly is installed, and then the nut sleeve assembly is fitted in. With the help of magnetic adsorption and bearing rotation mechanism, installation can be completed without complicated tools, which significantly reduces the difficulty and time cost of on-site construction.

[0018] 5. Reliable structure, combining fixed and rotational detection functions. This invention ensures reliable adhesion and positioning of the device on the nut, while allowing the rotating ring to rotate freely with the relative rotation of the bolt or nut, thereby accurately transmitting angular change signals and improving the stability and accuracy of long-term monitoring.

[0019] 6. Facilitates system integration and intelligent management. This invention features a standard cable connector, allowing for easy connection to wind turbine condition monitoring systems or industrial IoT platforms. This enables multi-bolt network monitoring and centralized data management, promoting the digital upgrade of wind turbine blade root connection health management. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is the front view of the present invention.

[0022] Figure 2 This is a top view of the present invention.

[0023] Figure 3 This is a cross-sectional view of the present invention. Detailed Implementation

[0024] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0025] See Figures 1 to 3 The figure shows an improved bolt loosening monitoring device, including a bolt cap 100, a magnet 200, a nut sleeve 300, a nut rotating sleeve 400, a rotating ring 500, and a PCB board 600.

[0026] The bolt cap 100 is threaded onto the end of the threaded portion 11 of the bolt 10.

[0027] Magnet 200 is disposed in the top surface of bolt cap 100. In this embodiment, a magnet mounting groove 110 is provided on the top surface of bolt cap 100, and magnet 200 is installed in the magnet mounting groove 110 of bolt cap 100 in an embedded manner to prevent magnet 200 from loosening. At the same time, the upper end surface of magnet 200 is flush with the top surface of bolt cap 100 to avoid increasing the height.

[0028] The nut sleeve 300 is fitted onto the outer circumferential surface of the nut 20 mounted on the screw portion 11. In this embodiment, six pot magnet mounting grooves 310 are evenly spaced circumferentially on the outer circumferential surface of the nut sleeve 300, and each pot magnet mounting groove 310 is embedded with a pot magnet 700. The magnetism of the pot magnet 700 securely attracts and fixes the nut sleeve 300 to the outer circumferential surface of the nut 20. Of course, the number of pot magnets 700 is not limited to that in this embodiment, and can be set according to installation requirements.

[0029] The nut swivel sleeve 400 is fitted onto the end of the nut sleeve 300 and located on the outer periphery of the bolt head 100. Furthermore, to facilitate height adjustment, at least one height-adjusting adapter sleeve 800 is provided between the nut sleeve 300 and the nut swivel sleeve 400. The adapter sleeve 800 is detachably connected to the nut sleeve 300 and the nut swivel sleeve 400 via threads. When different bolts have different protruding bolt lengths, the nut sleeve 300 can be accurately installed on the nut 20 by adding or removing the adapter sleeve 800, significantly improving the device's adaptability to different bolt specifications on site.

[0030] The rotating ring 500 is located inside the end of the nut rotating sleeve 400 and above the nut sleeve 300.

[0031] A PCB board 600 is disposed within the rotating ring 500 and above the magnet 200. The PCB board 600 integrates a magnetic induction chip (not shown) for collecting changes in the magnetic field of the magnet 200. In this embodiment, a PCB board mounting cavity 510 is formed within the rotating ring 500. The PCB board 600 is fixedly mounted within the PCB board mounting cavity 510 by means of snap-fit ​​or interference fit to prevent the PCB board 600 from becoming loose.

[0032] An outer annular flange 120 is formed on the top surface of the bolt cap 100. An inner annular flange 510 located on the inner circumference of the outer annular flange 120 is formed on the end face of the rotating ring 500 facing the bolt cap 100. A bearing 900 is provided on the top surface of the bolt cap 100 between the outer annular flange 120 and the inner annular flange 510. The outer circumferential surface of the outer ring of the bearing 900 contacts and connects with the inner annular surface of the outer annular flange 120, and the inner circumferential surface of its inner ring contacts and connects with the outer annular surface of the inner annular flange.

[0033] The improved bolt loosening monitoring device of the present invention also includes a cable connector 1000 and a data connection cable 1100. One end of the data connection cable 1100 is connected to the cable connector 1000, and the other end passes through the rotating ring 500 and is connected to the PCB board 600. The cable connector 1000 adopts a standard cable connector, which can be easily connected to the wind turbine condition monitoring system or industrial IoT platform to realize multi-bolt network monitoring and centralized data management, and promote the digital upgrade of wind turbine blade root connection health management.

[0034] The core principle of this invention is to determine whether the bolt is loose by detecting the relative rotation angle between the bolt and the nut. The working process is as follows: During initial installation, the bolt cap 100 is fixed to the end of the screw section 11 via a threaded connection and moves with the bolt. The nut sleeve 300 is attracted and fixed to the nut 20 by the magnet 700, and the nut rotating sleeve 400 is connected to the nut sleeve 300 via the adapter sleeve 800 and moves with the nut 20. The magnet 200 on the top surface of the bolt cap 100 is positioned opposite to the magnetic induction chip on the PCB board 600 inside the rotating ring 500.

[0035] When there is no relative rotation between bolt 10 and nut 20, the relative position of magnet 200 and magnetic induction chip remains unchanged, and the magnetic field signal detected by magnetic induction chip is constant. When bolt 10 loosens due to vibration or load change, a relative angular displacement occurs between bolt 10 and nut 20: bolt 10 drives bolt cap 100 and magnet 200 to rotate, while nut sleeve 300 and nut rotating sleeve 400 remain stationary due to adsorption on nut 20. At this time, PCB board 600 inside rotating ring 500 also remains stationary. The rotation of magnet 200 changes the magnetic field distribution it generates above magnetic induction chip. Magnetic induction chip detects the change in magnetic field direction or intensity in real time and converts this change into a corresponding angular change signal.

[0036] The PCB board 600 transmits the angle signal to the external monitoring system via the data connection cable 1100 and cable connector 1000. The system continuously records and displays the angle value of bolt loosening. When the cumulative rotation angle reaches the preset critical threshold, the system automatically issues an alarm, prompting maintenance personnel to perform timely pre-tightening.

[0037] Furthermore, the bearing 900 in this invention is located between the bolt cap 100 and the rotating ring 500, with its outer ring contacting the outer annular flange 120 and its inner ring contacting the inner annular flange 510. This allows the bolt cap 100 and the rotating ring 500 to achieve low-friction relative rotation, ensuring that angle changes are transmitted sensitively and smoothly, and avoiding signal lag or misjudgment caused by frictional resistance. By adjusting the number or length of the adapter sleeves 800, the installation requirements for different screw protrusion heights can be accommodated, ensuring that the device can establish the aforementioned angle detection relationship normally under various operating conditions.

[0038] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. An improved bolt loosening monitoring device, characterized by, include: A bolt cap fitted onto the end of the bolt's threaded portion; A magnet is disposed within the top surface of the bolt cap; A nut sleeve fitted onto the outer circumferential surface of a nut mounted on a screw section; A nut rotating sleeve that is fitted onto the end of the nut sleeve and located on the outer periphery of the bolt cap; A rotating ring, wherein the rotating ring is disposed inside the end of the nut rotating sleeve and located above the nut sleeve; as well as A PCB board is disposed inside the rotating ring and above the magnet, and a magnetic induction chip for collecting changes in the magnetic field of the magnet is integrated inside the PCB board.

2. The improved bolt loosening monitoring device of claim 1, wherein, The top surface of the bolt cap is provided with a magnet mounting groove, and the magnet is installed in the magnet mounting groove of the bolt cap. The upper end surface of the magnet is flush with the top surface of the bolt cap.

3. The improved bolt loosening monitoring device of claim 1, wherein, An outer annular flange is formed on the top surface of the bolt cap, and an inner annular flange located on the inner circumference of the outer annular flange is formed on the end face of the rotating ring facing the bolt cap. A bearing is provided on the top surface of the bolt cap between the outer annular flange and the inner annular flange.

4. The improved bolt loosening monitoring device of claim 1, wherein A PCB board mounting cavity is formed within the rotating ring, and the PCB board is mounted within the PCB board mounting cavity.

5. The improved bolt loosening monitoring device as claimed in claim 1, wherein, A plurality of pot magnet mounting grooves are provided circumferentially spaced on the outer circumferential surface of the nut sleeve, and a pot magnet is embedded in each pot magnet mounting groove.

6. The improved bolt loosening monitoring device as claimed in claim 1, wherein, At least one adapter sleeve for adjusting the height is provided between the nut sleeve and the nut rotating sleeve.

7. The improved bolt loosening monitoring device of claim 6, wherein, The bolt cap and the bolt shank, the nut sleeve and the adapter sleeve, and the adapter sleeve and the nut rotating sleeve are detachably connected by threads.

8. The improved bolt loosening monitoring device of any one of claims 1 to 7, wherein, It also includes a cable connector and a data connection cable, one end of which is connected to the cable connector, and the other end of which passes through the rotating ring and is connected to the PCB board.

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