A vibration monitoring device for a wind turbine blade
By designing a vibration monitoring device on the wind turbine blade that includes a disc spring, electromagnetic induction, and airflow damping, the problem of accelerometer being affected by foundation vibration was solved, and accurate monitoring and long-term stable operation under strong vibration conditions were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 葫芦岛全方新能源风电有限公司
- Filing Date
- 2026-02-02
- Publication Date
- 2026-06-09
AI Technical Summary
In existing wind turbine blade vibration monitoring devices, accelerometers are directly fixed to the blade surface, making them susceptible to foundation vibration. This results in interference signals being mixed into the monitoring data, making it difficult to accurately distinguish between normal and abnormal vibrations and affecting the accuracy of fault diagnosis.
A vibration monitoring device comprising a frame, housing, accelerometer, vibration damping mechanism and heat dissipation mechanism is adopted. It utilizes disc spring buffer, electromagnetic induction and damping adjustment mechanism, combined with airflow damping force, to reduce monitoring data error and improve accuracy.
This effectively reduces vibration interference from the accelerometer, ensuring accurate blade vibration data is collected under strong vibration conditions, extending the service life of the device, and improving the stability and accuracy of monitoring.
Smart Images
Figure CN121654572B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of blade vibration monitoring technology, and in particular to a vibration monitoring device for wind turbine blades. Background Technology
[0002] In the field of wind power generation, wind turbine blades, as the core component for energy capture, directly determine the overall power generation efficiency and safety stability of the turbine. As the capacity of individual wind turbines continues to increase, blade sizes are becoming larger and lighter. Under complex field conditions (such as strong winds, turbulence, and gust impacts), blades are prone to multi-mode vibration. Prolonged high-frequency or excessive vibration can not only lead to fatigue damage to the blade structure but may also cause collisions between the blade and the nacelle or tower, or even cause the entire turbine to shut down. Therefore, real-time and accurate vibration monitoring of wind turbine blades is a key technical means to achieve early warning of blade failures, extend blade lifespan, and ensure the safe and efficient operation of wind turbines.
[0003] In existing devices, accelerometers are usually fixed directly to the blade surface by a rigid bracket or simple clip. The basic vibration generated by the blade during normal rotation is directly transmitted to the accelerometer. The accelerometer itself is prone to additional nonlinear displacement with the basic vibration of the blade, resulting in a large number of interference signals mixed in the collected vibration data. It is difficult to accurately distinguish between normal and abnormal vibration of the blade, which in turn increases the linear error of the monitoring data and affects the accuracy of fault diagnosis.
[0004] In view of this, we have studied and improved the existing problems to provide a vibration monitoring device for wind turbine blades. The aim of this technology is to solve the problems and improve its practical value. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and to propose a vibration monitoring device for wind turbine blades.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: a vibration monitoring device for wind turbine blades, comprising a frame and a blade body mounted on the surface of the frame. A clamp is installed on the outer wall of the blade body, and a housing is welded to the outer wall of the clamp. An accelerometer is provided inside the housing, and a vibration damping mechanism is provided on the outer side of the accelerometer. The vibration damping mechanism includes a fixing ring sleeved on the outer wall of the accelerometer. Two sets of symmetrical rings are fixed inside the housing, and a disc spring is installed between the fixing ring and the rings. A fixing ring is provided inside the housing, and an excitation coil is spirally wound on the outer wall of the fixing ring. Magnetic blocks are installed at both ends of the accelerometer. A power board is installed inside the housing, and conductive plates are installed at both ends of the power board. A conductive copper plate slides on the inner wall of the conductive plate, and a connecting rod is fixed between the accelerometer and the conductive copper plate.
[0007] The inner wall of the housing is equipped with two sets of symmetrical damping cylinders. A damping plate slides inside each set of damping cylinders. A damping rod is installed between the two sets of damping plates. A connecting plate is fixed between the fixing ring and the damping rod. A conductive rod is inserted into the inside of the damping cylinder.
[0008] The excitation coil is provided with a heat dissipation mechanism on its outer side. The heat dissipation mechanism includes a flow guide shroud installed on the outer wall of the fixed coil. A spiral blade is fixed on the inner wall of the flow guide shroud. An air jet hole is opened on the side wall of the spiral blade along its spiral direction. An air extraction component for inflating the inner cavity is provided on the outer side of the flow guide shroud.
[0009] Preferably, the magnetic pole direction of the magnetic block is perpendicular to the axis of the accelerometer, and the opposite surfaces of the two sets of magnetic blocks have the same polarity.
[0010] Preferably, the damping cylinder is filled with magnetorheological fluid, and the connecting rod is made of insulating material.
[0011] Preferably, the excitation coil is electrically connected to the power board by a wire, the conductive sheet is electrically connected to the conductive copper plate, and the conductive copper plate is electrically connected to the conductive rod.
[0012] Preferably, the interior of the flow guide is hollow, the top of the flow guide is conical, the interior of the flow guide is connected to the jet hole, and the fixing ring is installed at the bottom of the interior of the flow guide.
[0013] Preferably, the air extraction assembly includes a sleeve installed inside the housing, a piston rod sliding inside the sleeve, a threaded sleeve fitted at the end of the piston rod away from the guide shroud, a gear fitted on the outer wall of the threaded sleeve, a rack meshing with the gear fixed on the outer wall of the fixing ring, an air supply pipe connecting the guide shroud and the sleeve, and an air extraction pipe connected at one end of the sleeve.
[0014] Preferably, one end of the piston rod is threaded, and the piston rod is threadedly connected to the threaded sleeve.
[0015] Preferably, a one-way exhaust valve is installed at the connection between the gas supply pipe and the piston rod, and a one-way intake valve is installed at the connection between the gas extraction pipe and the piston rod.
[0016] Preferably, the length of the rack is greater than the maximum displacement of the accelerometer within the elastic range of the disc spring.
[0017] Compared with the prior art, the beneficial effects of the present invention are:
[0018] 1. This invention utilizes the vibration of the wind turbine blade itself. In the initial state, the disc spring plays an elastic buffering role, absorbing part of the vibration energy through its own elastic deformation. This initially reduces the vibration amplitude of the accelerometer, reduces the linear error of the monitoring data caused by the accelerometer's own vibration, avoids the influence of initial vibration interference on the monitoring data, and ensures that the subsequently collected blade vibration data is more consistent with the actual situation.
[0019] 2. This invention utilizes the principle of electromagnetic induction. When the blade body is subjected to strong impact or vibration, the accelerometer displaces axially, causing the magnetic blocks at both ends to cut magnetic field lines within the excitation coil. The periodic change in the coil's magnetic flux generates an induced current, which is stored in the power supply board via a wire. Simultaneously, the accelerometer, through a connecting rod, drives a conductive copper plate to slide along a conductive sheet. When its connector aligns with the conductive rod of the damping cylinder, the circuit is completed, and current from the power supply board is transmitted to the damping cylinder. The viscosity of the magnetorheological fluid increases with the vibration amplitude, and the damping force increases synchronously, thus forming an adaptive damping adjustment mechanism. This further counteracts the energy generated by the blade body vibration, reduces the accelerometer's vibration response, and ensures that even under strong vibration conditions, the accelerometer can still collect accurate blade vibration data, providing precise data support for blade fault early warning. This improves the accuracy of the accelerometer monitoring data and reduces damage to other internal components of the accelerometer, extending the service life of the entire vibration monitoring device and enhancing its stability during long-term wind turbine operation.
[0020] 3. In this invention, the fixed ring moves synchronously with the accelerometer, thereby driving the rack fixed on its outer wall to move axially. The movement of the rack drives the gear to rotate, and the gear drives the threaded sleeve to rotate synchronously. The rotation of the threaded sleeve is converted into the reciprocating sliding of the piston rod inside the sleeve, realizing the suction of air inside the sleeve. The cold air inside the sleeve is forced into the hollow inner cavity of the guide shroud through the air supply pipe. The cold air entering the inner cavity of the guide shroud is ejected along the air jet holes on the surface of the spiral blade and directly acts on the surface of the excitation coil wound on the outer wall of the fixed ring, forming a spiral airflow. The spirally ejected cold air can directly cover the surface of the excitation coil, quickly removing the heat generated during its operation, effectively avoiding the electromagnetic performance decay of the excitation coil due to high temperature, ensuring that the excitation coil can stably generate a magnetic field that matches the vibration amplitude, thereby ensuring the vibration reduction effect and the monitoring accuracy of the accelerometer. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention;
[0022] Figure 2 This is a partial structural schematic diagram of the present invention;
[0023] Figure 3 This is a schematic cross-sectional view of the housing structure of the present invention;
[0024] Figure 4 This is a schematic diagram of the vibration reduction mechanism of the present invention;
[0025] Figure 5 For the present invention Figure 4 Enlarged structural diagram of section A;
[0026] Figure 6 This is a schematic diagram of the heat dissipation mechanism of the present invention;
[0027] Figure 7 For the present invention Figure 6 Enlarged structural diagram of section B.
[0028] Legend:
[0029] 1. Frame; 2. Blade body; 4. Clamp; 5. Housing; 6. Accelerometer; 7. Vibration damping mechanism; 71. Fixed ring; 72. Circular ring; 73. Disc spring; 74. Fixed ring; 75. Excitation coil; 76. Magnetic block; 77. Power board; 78. Wire; 79. Conductive sheet; 710. Conductive copper plate; 711. Connecting rod; 712. Damping cylinder; 713. Damping rod; 714. Connecting plate; 715. Conductive rod; 716. Damping plate; 8. Heat dissipation mechanism; 81. Radiator; 82. Spiral blade; 83. Jet nozzle; 84. Sleeve; 85. Piston rod; 86. Threaded sleeve; 87. Gear; 88. Rack; 89. Gas delivery pipe; 810. Extraction pipe. Detailed Implementation
[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0031] See Figures 1 to 7As shown, the present invention provides a vibration monitoring device for wind turbine blades, including a frame 1 and a blade body 2 mounted on the surface of the frame 1. A clamp 4 is installed on the outer wall of the blade body 2, and a housing 5 is welded to the outer wall of the clamp 4. An accelerometer 6 is provided inside the housing 5, and a vibration damping mechanism 7 is provided on the outer side of the accelerometer 6. The vibration damping mechanism 7 includes a fixing ring 71 sleeved on the outer wall of the accelerometer 6. Two sets of symmetrical rings 72 are fixed inside the housing 5. A disc spring 73 is installed between the fixing ring 71 and the rings 72. A fixing ring 74 is provided inside the housing 5. An excitation coil 75 is spirally wound on the outer wall of the fixing ring 74. Magnetic blocks 76 are installed at both ends of the accelerometer 6. A power board 77 is installed inside the housing 5. Conductive plates 79 are installed at both ends of the power board 77. A conductive copper plate 710 slides on the inner wall of the conductive plate 79. A connecting rod 711 is fixed between the accelerometer 6 and the conductive copper plate 710.
[0032] Two sets of symmetrical damping cylinders 712 are installed on the inner wall of the housing 5. A damping plate 716 slides inside each set of damping cylinders 712. A damping rod 713 is installed between the two sets of damping plates 716. A connecting plate 714 is fixed between the fixing ring 71 and the damping rod 713. A conductive rod 715 is inserted into the inside of the damping cylinder 712.
[0033] It should be noted that when the wind turbine blade body 2 vibrates due to operation, the vibration is first transmitted to the housing 5 through the clamp 4 installed on the outer wall of the blade body 2, and then acts on the accelerometer 6 installed inside the housing 5. In the initial state, the disc spring 73 plays an elastic buffering role, and absorbs part of the vibration energy by its own elastic deformation, which initially reduces the vibration amplitude of the accelerometer 6, reduces the linear error of the monitoring data caused by the vibration of the accelerometer 6 itself, avoids the influence of the initial vibration interference on the monitoring data, and ensures that the blade vibration data collected later is more in line with the actual situation.
[0034] When the blade body 2 is subjected to a large impact force or vibration, the accelerometer 6 will be displaced along its axial direction. During the displacement, the magnetic blocks 76 installed at both ends of the accelerometer 6 will move synchronously with the accelerometer 6. The movement of the magnetic blocks 76 will cause them to continuously cut magnetic field lines within the excitation coil 75. According to the principle of electromagnetic induction, the reciprocating motion of the magnetic blocks 76 causes the magnetic flux within the excitation coil 75 to change periodically, thereby generating an induced electromotive force and an induced current in the excitation coil 75, realizing the conversion of the kinetic energy generated by vibration into electrical energy. The generated current is transmitted to the power board 77 installed inside the housing 5 for storage through the wire 78 electrically connected to the excitation coil 75 and the power board 77.
[0035] Meanwhile, as the accelerometer 6 vibrates and moves back and forth, it drives the conductive copper plate 710 to move via the connecting rod 711. This causes the conductive copper plate 710 to slide along the inner wall of the conductive plates 79 installed at both ends of the power board 77. When the socket on the surface of the conductive copper plate 710 aligns with the outer wall of the conductive rod 715 inserted inside the damping cylinder 712, a circuit is formed. The current stored in the power board 77 is transmitted sequentially through the conductive plates 79, the conductive copper plate 710, and the conductive rod 715 to the inside of the damping cylinder 712. Since the inside of the damping cylinder 712 is filled with magnetorheological fluid, the current passing through it changes the magnetic field environment inside the damping cylinder 712, causing the magnetorheological fluid to change from a liquid state to a solid state. When the fixed ring 71 vibrates with the accelerometer 6, the fixed ring 71 drives the damping rod 713 and the damping plate 716 to slide inside the damping cylinder 712 via the connecting plate 714. At this time, the viscosity of the magnetorheological fluid inside the damping cylinder 712 changes. The vibration amplitude of the accelerometer 6 directly changes the resistance of the sliding of the damping plate 716. The greater the vibration amplitude of the accelerometer 6, the greater the displacement of the magnetic block 76. The higher the speed and frequency at which the magnetic block 76 cuts the magnetic field lines, the more obvious the change in current generated in the excitation coil 75, the stronger the corresponding magnetic field strength, and the higher the viscosity of the magnetorheological fluid. The greater the damping force experienced by the damping plate 716 when it slides, thus forming an adaptive damping adjustment mechanism. This further counteracts the energy generated by the vibration of the blade body 2, reduces the vibration response of the accelerometer 6, and ensures that even under strong vibration conditions, the accelerometer 6 can still collect accurate blade vibration data, providing accurate data support for blade fault early warning. This improves the accuracy of the monitoring data of the accelerometer 6, while also reducing the damage of vibration to other internal components of the accelerometer 6, extending the service life of the entire vibration monitoring device, and improving the stability of the device during long-term operation of the wind turbine.
[0036] The excitation coil 75 is provided with a heat dissipation mechanism 8 on its outer side. The heat dissipation mechanism 8 includes a flow guide shroud 81 installed on the outer wall of the fixed ring 74. A spiral blade 82 is fixed on the inner wall of the flow guide shroud 81. An air jet hole 83 is opened on the side wall of the spiral blade 82 along its spiral direction. An air extraction assembly for inflating the inner cavity is provided on the outer side of the flow guide shroud 81.
[0037] It should be noted that when the blade body 2 vibrates and causes the accelerometer 6 to move, the fixed ring 71 will move synchronously with the accelerometer 6, thereby causing the rack 88 fixed on its outer wall to move axially. Since the rack 88 meshes with the gear 87, the movement of the rack 88 will drive the gear 87 to rotate. The gear 87 will drive the threaded sleeve 86 to rotate synchronously. Since the piston rod 85 is threadedly connected to the threaded sleeve 86, the rotation of the threaded sleeve 86 will be converted into the reciprocating sliding of the piston rod 85 in the sleeve 84. When the piston rod 85 slides away from the guide shroud 81, a negative pressure is formed inside the sleeve 84. At this time, the one-way intake valve opens and the one-way exhaust valve closes. External cold air is drawn into the sleeve 84 through the suction pipe 810. When the piston rod 85 slides towards the guide shroud 81... During sliding, the internal pressure of the sleeve 84 increases, the one-way exhaust valve opens and the one-way intake valve closes. The cold air inside the sleeve 84 is forced into the hollow inner cavity of the guide shroud 81 through the air supply pipe 89. The cold air entering the inner cavity of the guide shroud 81 will be ejected along the jet holes 83 on the surface of the spiral blade 82 and directly act on the surface of the excitation coil 75 wound on the outer wall of the fixed ring 74, forming a spiral airflow. The spirally ejected cold air can directly cover the surface of the excitation coil 75, quickly remove the heat generated during its operation, effectively avoid the electromagnetic performance decay of the excitation coil 75 due to high temperature, ensure that the excitation coil 75 can stably generate a magnetic field that matches the vibration amplitude, and thus ensure the vibration reduction effect and the monitoring accuracy of the accelerometer 6.
[0038] Meanwhile, guided by the spiral blades 82, the cold air flows directly upward along the interior of the shroud 81. Due to the conical structure at the top of the shroud 81, the internal space of the shroud 81 gradually narrows from bottom to top. As the airflow rises, the rotation speed is further accelerated due to the compression of the space, and it blows upward toward the bottom of the accelerometer 6. This provides additional airflow damping force for the vibration of the accelerometer 6. When the accelerometer 6 is displaced downward due to the vibration of the blades, the bottom will directly collide with the upward-flowing spiral wind. The airflow will generate an upward reaction force on its downward movement, slowing down the speed and amplitude of the downward displacement, further weakening the vibration amplitude of the accelerometer 6, allowing the accelerometer 6 to reach a stable state more quickly, avoiding fluctuations in monitoring data caused by severe vibration, and further improving the monitoring accuracy of the accelerometer 6.
[0039] See Figure 4 As shown, the magnetic pole direction of the magnetic block 76 is perpendicular to the axis of the accelerometer 6, and the opposite surfaces of the two sets of magnetic blocks 76 have the same polarity.
[0040] See Figures 4 to 5 As shown, the damping cylinder 712 is filled with magnetorheological fluid, and the connecting rod 711 is made of insulating material. The insulating material can prevent the current of the conductive parts from being conducted to the accelerometer 6, thus preventing the current from interfering with the monitoring function of the accelerometer 6.
[0041] See Figure 4 As shown, the excitation coil 75 is electrically connected to the power board 77 by a wire 78, the conductive sheet 79 is electrically connected to the conductive copper plate 710, and the conductive copper plate 710 is electrically connected to the conductive rod 715.
[0042] See Figure 6 As shown, the interior of the deflector 81 is hollow, the top of the deflector 81 is conical, the interior of the deflector 81 is connected to the jet hole 83, and the fixing ring 74 is installed at the bottom of the interior of the deflector 81.
[0043] See Figures 6 to 7 As shown, the air extraction assembly includes a sleeve 84 installed inside the housing 5. A piston rod 85 slides inside the sleeve 84. A threaded sleeve 86 is fitted on the end of the piston rod 85 away from the guide shroud 81. A gear 87 is fitted on the outer wall of the threaded sleeve 86. A rack 88 that meshes with the gear 87 is fixed on the outer wall of the fixing ring 71. An air supply pipe 89 connects the guide shroud 81 and the sleeve 84. An air extraction pipe 810 is connected to one end of the sleeve 84.
[0044] See Figure 7 As shown, one end of the piston rod 85 is threaded, and the piston rod 85 is threadedly connected to the threaded sleeve 86. When the rack 88 drives the gear 87 to rotate, the threaded sleeve 86 rotates synchronously with the gear 87. Through the threaded engagement, the rotational motion is converted into the reciprocating linear motion of the piston rod 85 in the sleeve 84, thereby realizing the intake and exhaust of cold air in the sleeve 84.
[0045] See Figure 7 As shown, a one-way exhaust valve is installed at the connection between the gas supply pipe 89 and the piston rod 85, and a one-way intake valve is installed at the connection between the exhaust pipe 810 and the piston rod 85. The one-way exhaust valve and the one-way intake valve can ensure the normal flow of gas.
[0046] See Figure 6 As shown, the length of rack 88 is greater than the maximum displacement of accelerometer 6 within the elastic range of disc spring 73, which ensures that rack 88 always meshes with gear 87 within the maximum vibration displacement range of accelerometer 6, avoiding transmission interruption due to rack 88 being too short, and maintaining the reciprocating sliding of piston rod 85.
[0047] Working principle: When the wind turbine blade body 2 vibrates due to operation, the vibration will first be transmitted to the housing 5 through the clamp 4 installed on the outer wall of the blade body 2, and then act on the accelerometer 6 installed inside the housing 5. In the initial state, the disc spring 73 plays an elastic buffering role and absorbs part of the vibration energy by its own elastic deformation.
[0048] When the blade body 2 is subjected to a large impact force or vibration, the accelerometer 6 will be displaced along its axial direction. During the displacement, the magnetic blocks 76 installed at both ends of the accelerometer 6 will move synchronously with the accelerometer 6. The movement of the magnetic blocks 76 will cause them to continuously cut magnetic field lines within the excitation coil 75. According to the principle of electromagnetic induction, the reciprocating motion of the magnetic blocks 76 causes the magnetic flux within the excitation coil 75 to change periodically, thereby generating an induced electromotive force and an induced current in the excitation coil 75, realizing the conversion of the kinetic energy generated by vibration into electrical energy. The generated current is transmitted to the power board 77 installed inside the housing 5 for storage through the wire 78 electrically connected to the excitation coil 75 and the power board 77.
[0049] Meanwhile, as the accelerometer 6 moves back and forth under vibration, it drives the conductive copper plate 710 to move via the connecting rod 711. This causes the conductive copper plate 710 to slide along the inner wall of the conductive plates 79 installed at both ends of the power board 77. When the socket on the surface of the conductive copper plate 710 aligns with the outer wall of the conductive rod 715 inserted inside the damping cylinder 712, a circuit is formed. The current stored in the power board 77 is transmitted sequentially through the conductive plates 79, the conductive copper plate 710, and the conductive rod 715 to the inside of the damping cylinder 712. Since the inside of the damping cylinder 712 is filled with magnetorheological fluid, the current passing through it changes the magnetic field environment inside the damping cylinder 712, causing the magnetorheological fluid to change from liquid to liquid. When the fixed ring 71 vibrates with the accelerometer 6, it will drive the damping rod 713 and the damping plate 716 to slide in the damping cylinder 712 through the connecting plate 714. At this time, the viscosity change of the magnetorheological fluid in the damping cylinder 712 will directly change the resistance of the sliding of the damping plate 716. The greater the vibration amplitude of the accelerometer 6, the greater the displacement of the magnetic block 76. The higher the speed and frequency of the magnetic block 76 cutting the magnetic field lines, the more obvious the change of current generated in the excitation coil 75, the stronger the corresponding magnetic field strength, the higher the viscosity of the magnetorheological fluid, and the greater the damping force when the damping plate 716 slides, thus forming an adaptive damping adjustment mechanism.
[0050] When the blade body 2 vibrates and causes the accelerometer 6 to move, the fixed ring 71 moves synchronously with the accelerometer 6, which in turn causes the rack 88 fixed on its outer wall to move axially. Since the rack 88 meshes with the gear 87, the movement of the rack 88 will drive the gear 87 to rotate. The gear 87 will drive the threaded sleeve 86 to rotate synchronously. Because the piston rod 85 is threadedly connected to the threaded sleeve 86, the rotation of the threaded sleeve 86 will be converted into the reciprocating sliding of the piston rod 85 in the sleeve 84. When the piston rod 85 slides away from the guide shroud 81, a reciprocating sliding motion is formed inside the sleeve 84. When the pressure is negative, the one-way intake valve opens and the one-way exhaust valve closes. External cold air is drawn into the sleeve 84 through the suction pipe 810. When the piston rod 85 slides towards the guide shroud 81, the pressure inside the sleeve 84 increases. The one-way exhaust valve opens and the one-way intake valve closes. The cold air inside the sleeve 84 is forced into the hollow cavity of the guide shroud 81 through the air supply pipe 89. The cold air entering the cavity of the guide shroud 81 will be ejected along the jet holes 83 on the surface of the spiral blade 82 and directly act on the surface of the excitation coil 75 wound on the outer wall of the fixed ring 74.
[0051] Meanwhile, under the guidance of the spiral blades 82, the cold air flows directly upward along the inside of the shroud 81. Since the top of the shroud 81 adopts a conical structure, the internal space of the shroud 81 gradually narrows from bottom to top. During the upward process, the airflow is compressed by the space, and the rotation speed is further accelerated and blown upward toward the bottom of the accelerometer 6, thereby providing additional airflow damping force for the vibration of the accelerometer 6.
[0052] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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 vibration monitoring device for wind turbine blades, comprising a frame (1) and a blade body (2) mounted on the surface of the frame (1), wherein a clamp (4) is installed on the outer wall of the blade body (2), a housing (5) is welded to the outer wall of the clamp (4), and an accelerometer (6) is provided inside the housing (5), characterized in that: The accelerometer (6) is provided with a vibration damping mechanism (7) on its outer side. The vibration damping mechanism (7) includes a fixing ring (71) sleeved on the outer wall of the accelerometer (6). Two sets of symmetrical rings (72) are fixed inside the housing (5). A disc spring (73) is installed between the fixing ring (71) and the ring (72). A fixing ring (74) is provided inside the housing (5). An excitation coil (75) is spirally wound on the outer wall of the fixing ring (74). Magnetic blocks (76) are installed at both ends of the accelerometer (6). A power board (77) is installed inside the housing (5). Conductive plates (79) are installed at both ends of the power board (77). A conductive copper plate (710) slides on the inner wall of the conductive plate (79). A connecting rod (711) is fixed between the accelerometer (6) and the conductive copper plate (710). The inner wall of the housing (5) is equipped with two sets of symmetrical damping cylinders (712). A damping plate (716) slides inside each set of damping cylinders (712). A damping rod (713) is installed between the two sets of damping plates (716). A connecting plate (714) is fixed between the fixing ring (71) and the damping rod (713). A conductive rod (715) is inserted into the inside of the damping cylinder (712). The excitation coil (75) is provided with a heat dissipation mechanism (8) on the outside. The heat dissipation mechanism (8) includes a flow guide (81) installed on the outer wall of the fixed ring (74). A spiral blade (82) is fixed on the inner wall of the flow guide (81). An air jet hole (83) is opened on the side wall of the spiral blade (82) along its spiral direction. An air extraction assembly for inflating the inner cavity is provided on the outside of the flow guide (81). The air extraction assembly includes a sleeve (84) installed inside the housing (5), a piston rod (85) sliding inside the sleeve (84), a threaded sleeve (86) sleeved at the end of the piston rod (85) away from the flow guide (81), a gear (87) sleeved on the outer wall of the threaded sleeve (86), a rack (88) meshing with the gear (87) fixed on the outer wall of the fixing ring (71), an air supply pipe (89) connecting the flow guide (81) and the sleeve (84), and an air extraction pipe (810) connecting one end of the sleeve (84). One end of the piston rod (85) is threaded, and the piston rod (85) is threadedly connected to the threaded sleeve (86).
2. The vibration monitoring device for wind turbine blades according to claim 1, characterized in that: The magnetic pole direction of the magnetic block (76) is perpendicular to the axis of the accelerometer (6), and the opposite surfaces of the two sets of magnetic blocks (76) have the same polarity.
3. The vibration monitoring device for wind turbine blades according to claim 1, characterized in that: The damping cylinder (712) is filled with magnetorheological fluid, and the connecting rod (711) is made of insulating material.
4. The vibration monitoring device for wind turbine blades according to claim 1, characterized in that: The excitation coil (75) is electrically connected to the power board (77) by a wire (78), the conductive sheet (79) is electrically connected to the conductive copper plate (710), and the conductive copper plate (710) is electrically connected to the conductive rod (715).
5. The vibration monitoring device for wind turbine blades according to claim 1, characterized in that: The interior of the flow guide (81) is hollow, the top of the flow guide (81) is conical, the interior of the flow guide (81) is connected to the jet hole (83), and the fixing ring (74) is installed at the bottom of the interior of the flow guide (81).
6. The vibration monitoring device for wind turbine blades according to claim 1, characterized in that: A one-way exhaust valve is installed at the connection between the gas supply pipe (89) and the piston rod (85), and a one-way suction valve is installed at the connection between the suction pipe (810) and the piston rod (85).
7. The vibration monitoring device for wind turbine blades according to claim 1, characterized in that: The length of the rack (88) is greater than the maximum displacement of the accelerometer (6) within the elastic range of the disc spring (73).