Shaft voltage monitoring device and wind power gear box

Abstract

The invention belongs to the technical field of wind power gear boxes, and discloses a shaft voltage monitoring device and a wind power gear box. The shaft voltage monitoring device comprises an excitation circuit and at least two monitoring modules, each monitoring module comprises a conductive probe, a mounting seat and an elastic piece, the conductive probes penetrate through the mounting seats, and the elastic pieces apply elastic force close to a rotating body to the conductive probes so that the ends of the conductive probes can abut against the rotating body to be monitored; the excitation circuit is used for connecting the two monitoring modules, one end of the excitation circuit is electrically connected with one conductive probe, and the other end of the excitation circuit is electrically connected with the other conductive probe. The shaft voltage monitoring device can perform real-time voltage monitoring on the rotating body, and by arranging the monitoring module and the elastic piece, the reliability of contact between the conductive probe and the rotating body is ensured, and the failure rate of the wind power gear box is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power gearboxes, and in particular to a shaft voltage monitoring device and a wind power gearbox. Background Art

[0002] In wind power generation systems, the gearbox is a key component. Its shaft connects to the generator's shaft, transferring torque from the blade assembly to the generator for power generation. During operation, the gearbox generates shaft voltage, caused by the potential difference between the shaft and bearings. This is an electromagnetic phenomenon resulting from various factors. When the shaft voltage exceeds a certain threshold, the lubricating oil film in the shaft bearings breaks down, generating shaft currents that can damage the bearings through electrical corrosion, leading to gearbox failure.

[0003] During the long-term operation of the gearbox, the existing shaft voltage elimination device often has poor contact between the conductive probe and the rotating shaft due to wear or contamination, resulting in the shaft voltage elimination device being unable to play its original role and thus unable to eliminate the voltage on the rotating shaft in time. Summary of the Invention

[0004] The object of the present invention is to provide a shaft voltage monitoring device and a wind turbine gearbox, which can monitor the shaft voltage of a rotating body in real time and effectively avoid poor contact between a conductive probe and the rotating body.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A shaft voltage monitoring device comprising:

[0007] At least two monitoring modules, each comprising a conductive probe, an elastic member, and a mounting seat, wherein the conductive probe is inserted into the mounting seat, and the elastic member applies an elastic force to the conductive probe so that an end of the conductive probe can abut against a rotating body to be monitored;

[0008] An excitation circuit is used to connect the two monitoring modules, one end of the excitation circuit is electrically connected to one of the conductive probes, and the other end of the excitation circuit is electrically connected to the other conductive probe.

[0009] Preferably, a mounting hole is provided on the mounting seat, the conductive probe is passed through the mounting hole, and the elastic member is arranged in the mounting hole.

[0010] Preferably, the monitoring module further comprises an insulating tube, which is fixedly sleeved on the conductive probe and passed through the mounting hole.

[0011] Preferably, a sealing ring is provided between the inner wall surface of the mounting hole and the insulating cylinder.

[0012] Preferably, the mounting hole is a stepped hole, one end of the elastic member abuts against the stepped surface of the mounting hole, and the other end of the elastic member abuts against the limiting portion of the insulating cylinder.

[0013] Preferably, a stopper is provided on the insulating cylinder, and the stopper is located outside the mounting hole and can abut against the mounting seat along the moving direction of the insulating cylinder.

[0014] Preferably, the monitoring module further comprises a temperature sensor, and a probe of the temperature sensor is arranged on the conductive probe;

[0015] And / or, the monitoring module further includes a vibration sensor, and a probe of the vibration sensor is arranged on the conductive probe.

[0016] The wind turbine gearbox includes a mounting box, a rotating body and the above-mentioned shaft voltage monitoring device. At least part of the rotating body is arranged inside the mounting box. A monitoring port is opened on the mounting box, and the conductive probe is inserted into the monitoring port.

[0017] Preferably, two monitoring ports and two monitoring modules are provided, the two monitoring ports are spaced apart along the circumference of the rotating body, and one monitoring module is provided at each monitoring port.

[0018] Preferably, the mounting seat is threadedly connected to the monitoring port.

[0019] The beneficial effects of the present invention are:

[0020] The shaft voltage monitoring device provided by the present invention includes at least two monitoring modules of the excitation circuit. Since the conductive probe is inserted into the mounting seat and abuts against the rotating body, the conductive probes of any two monitoring modules can be connected outside the mounting box through the excitation circuit to form a conductive loop, thereby detecting the shaft voltage of the rotating body. When the shaft voltage reaches the set threshold, the conductive probe can be eliminated and discharged through a grounding device or a power resistor; since at least two monitoring modules are provided on the wind turbine gearbox, the conductive probes of any two monitoring modules can be connected into a conductive loop through the excitation circuit and an excitation current can be input, and the contact between the conductive probe and the rotating body can be checked by detecting whether there is current in the conductive loop, thereby ensuring the reliability of the rotating body voltage monitoring; in addition, since the monitoring module also includes an elastic part, the elastic part can apply an elastic force close to the rotating body to the conductive probe, so that the conductive probe is always abutted against the rotating body, thereby avoiding poor contact caused by wear between the conductive probe and the rotating body.

[0021] The wind turbine gearbox provided by the present invention includes an installation box, a rotating body and the above-mentioned shaft voltage monitoring device. It has a simple structure and is easy to operate. The monitoring module can perform real-time voltage monitoring on the rotating body inside the installation box. By providing at least two monitoring modules and elastic parts, the reliability of the contact between the conductive probe and the rotating body and the connectivity of the conductive circuit are guaranteed, thereby reducing the failure rate of the wind turbine gearbox caused by excessive shaft voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a partial cross-sectional view of a wind turbine gearbox provided in a specific embodiment of the present invention;

[0023] Figure 2 is a side view of a wind turbine gearbox provided in a specific embodiment of the present invention;

[0024] Figure 3 is a cross-sectional view of a shaft voltage monitoring device provided in a specific embodiment of the present invention;

[0025] Figure 4 It is a schematic diagram of the installation of the shaft voltage detection device provided in other embodiments of the present invention.

[0026] In the picture:

[0027] 100-Install the cabinet;

[0028] 200-rotating body;

[0029] 300 planetary gears;

[0030] 400-planet carrier;

[0031] 500-sun gear shaft;

[0032] 600-shell;

[0033] 1- monitoring module; 11- conductive probe; 111- convex portion; 12- elastic member; 13- mounting seat; 14- insulating tube; 141- stopper; 142- limiting portion; 15- sealing ring. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0035] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0036] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0037] In the description of this embodiment, terms such as "upper," "lower," "right," and "left" are used to refer to positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0038] like Figure 1 and Figure 3 As shown, the present invention provides a shaft voltage monitoring device, including an excitation circuit and at least two monitoring modules 1, the monitoring module 1 including a conductive probe 11, an elastic member 12 and a mounting seat 13, the conductive probe 11 is inserted into the mounting seat 13, and the elastic member 12 applies an elastic force to the conductive probe 11 so that the end of the conductive probe 11 can abut against the rotating body 200 to be monitored; the excitation circuit is used to connect the two monitoring modules 1, one end of the excitation circuit is electrically connected to one of the conductive probes 11, and the other end of the excitation circuit is electrically connected to the other conductive probe 11.

[0039] In this embodiment, since the conductive probe 11 is passed through the mounting seat 13 and abuts against the rotating body 200, the conductive probes 11 of any two monitoring modules 1 can be connected outside the mounting box 100 through an excitation circuit to form a conductive loop, thereby detecting the shaft voltage of the rotating body 200. When the shaft voltage reaches a set threshold, the conductive probe 11 can be eliminated and discharged through a grounding device or a power resistor. Since at least two monitoring modules 1 are provided on the wind turbine gearbox, the conductive probes 11 of any two monitoring modules 1 can be connected to form a conductive loop through an excitation circuit and an excitation current can be input. The contact between the conductive probe 11 and the rotating body 200 can be checked by detecting whether there is current in the conductive loop, thereby ensuring the reliability of the voltage monitoring of the rotating body 200. In addition, since the monitoring module 1 also includes an elastic member 12, the elastic member 12 can apply an elastic force close to the rotating body 200 to the conductive probe 11, so that the conductive probe 11 always abuts against the rotating body 200, thereby avoiding poor contact caused by wear between the conductive probe 11 and the rotating body 200.

[0040] Specifically, the mounting seat 13 is installed on the mounting box 100 of the wind turbine gearbox, and the rotating body 200 is passed through the mounting box 100. The conductive probes 11 of the two monitoring modules 1 and the excitation circuit outside the mounting box 100 form a conductive circuit. The excitation circuit is connected to the external control center. A relay is also provided on the excitation circuit. The control center can collect the shaft voltage of the rotating body 200 through the excitation circuit and can control the on and off of the conductive circuit through the relay; before use, the relay turns on the conductive circuit, and the excitation circuit will input the excitation current into the conductive circuit. If the control center can detect that there is current in the excitation circuit, it means that the conductive probes 11 of the two monitoring modules 1 are in contact with the rotating body 200 and the contact is good; if the control center detects that there is no current in the conductive circuit or the resistance is infinite, it means that one or both of the conductive probes 11 are in poor contact with the rotating body 200, and the staff needs to repair or replace the monitoring module 1 for monitoring. A power resistor is also provided on the excitation circuit. During the real-time monitoring of the shaft voltage by the monitoring module 1, if the control center detects that the shaft voltage reaches the set threshold, the control center will turn on the conductive circuit through the relay, and the current generated by the shaft voltage will be consumed and discharged in the form of heat through the power resistor.

[0041] like Figure 3As shown, a mounting hole is provided on the mounting seat 13, the conductive probe 11 is inserted into the mounting hole, and the elastic member 12 is arranged in the mounting hole; specifically, a monitoring port is provided on the mounting box 100, a thread is provided on the outer peripheral surface of the mounting seat 13, and a thread is also provided on the inner wall surface of the monitoring port. The mounting seat 13 is screwed to the monitoring port, and the conductive probe 11 is inserted into the mounting hole of the mounting seat 13, thereby facilitating the disassembly and assembly of the conductive probe 11. The specific structure of the mounting seat 13 can be set according to actual needs, as long as it can achieve a threaded connection with the monitoring port and fix the conductive probe 11; illustratively, the mounting seat 13 includes an integrally formed head and a rod, the rod is a cylindrical structure, and a thread is provided on the outer peripheral surface of the rod to be threadedly connected to the monitoring port. The head is a hexagonal nut commonly used in the art, so as to facilitate screwing; the head of the mounting seat 13 is provided with a through first hole groove, and the rod has a through second hole groove, and the first hole groove and the second hole groove constitute the mounting hole of the mounting seat 13.

[0042] In this embodiment, if Figure 3 As shown, the monitoring module 1 also includes an insulating tube 14, which is fixedly mounted on the conductive probe 11 and inserted into the mounting hole. The insulating tube 14 is made of an insulating material to prevent the conductive probe 11 from connecting to the mounting box 100 through the mounting seat 13 to form a conductive path, thereby affecting the final shaft voltage monitoring results. Specifically, the insulating tube 14 is a cylindrical structure with one end open. The conductive probe 11 is inserted into the insulating tube 14, and the insulating tube 14 is inserted into the mounting hole. The blocked end of the insulating tube 14 extends out of the mounting seat 13 and is located outside the mounting box 100. The insulating tube 14 can slide relative to the mounting seat 13. It is understood that a through hole is opened on the blocked end of the insulating tube 14, and the transmission line of the conductive probe 11 is connected to the excitation circuit through the through hole.

[0043] In order to improve the sealing between the insulating cylinder 14 and the mounting seat 13 and prevent the lubricating oil inside the mounting box 100 from leaking, as shown in FIG. Figure 3 As shown, a sealing ring 15 is provided between the inner wall surface of the mounting hole and the insulating tube 14. The sealing ring 15 is an annular rubber sealing structure commonly used in this field. It is sleeved on the insulating tube 14 and abuts against the inner wall surface of the mounting hole. It can prevent external dust, water vapor, etc. from entering the interior of the mounting box 100 and contaminating the internal structure. At the same time, it can also prevent the lubricating oil inside the mounting box 100 from leaking out.

[0044] like Figure 3As shown, the mounting hole is a stepped hole, one end of the elastic member 12 abuts against the stepped surface of the mounting hole, and the other end of the elastic member 12 abuts against the limiting portion 142 of the insulating cylinder 14. The insulating cylinder 14 can drive the conductive probe 11 to move, so that under the elastic force of the elastic member 12, the insulating cylinder 14 and the conductive probe 11 can move synchronously in a direction close to the rotating body 200, ensuring that the conductive probe 11 always abuts against the rotating body 200.

[0045] Specifically, the cooperation mode between the insulating tube 14 and the conductive probe 11 can be set according to actual conditions, as long as the two can achieve synchronous movement under the elastic force of the elastic member 12; for example, Figure 3 As shown, a protrusion 111 is provided near the center of the conductive probe 11. The opening of the insulating tube 14 is folded outward to form a stopper 142. The end of the conductive probe 11 is inserted into the insulating tube 14 through the opening, and the stopper 142 of the insulating tube 14 abuts against the protrusion 111 in the direction close to the rotating body 200. The elastic member 12 is a spring and is sandwiched between the mounting seat 13 and the stopper 142 in a compressed state. When the conductive probe 11 or the rotating body 200 wears, the insulating tube 14, under the elastic force of the elastic member 12, pushes the conductive probe 11 to move through the stopper 142, so that the conductive probe 11 always abuts against the rotating body 200, ensuring the conductive connection between the conductive probe 11 and the rotating body 200. The inner diameter of the first hole in the head of the mounting seat 13 is smaller than the inner diameter of the second hole in the rod. Therefore, the first and second holes form a stepped mounting hole along the axial direction, which facilitates the installation of the elastic member 12.

[0046] like Figure 3 As shown, a stopper 141 is provided on the insulating cylinder 14. The stopper 141 is located on the outside of the mounting hole and can abut against the mounting seat 13 along the moving direction of the insulating cylinder 14. The stopper 141 can prevent the insulating cylinder 14 from completely entering the mounting hole under the elastic force of the elastic member 12, thereby avoiding the mounting hole from being penetrated and causing poor sealing; specifically, the end of the insulating cylinder 14 away from the rotating body 200 extends out of the mounting seat 13 and is located outside the mounting box 100, and the stopper 141 is fixedly provided on the end of the insulating cylinder 14 extending out of the mounting seat 13; the specific structure and shape of the stopper 141 are not limited, as long as it can abut against the mounting seat 13.

[0047] It is understood that the shaft voltage monitoring device can monitor the voltage of any rotating body 200 that rotates and generates shaft voltage, such as the output shaft of the wind turbine gearbox, the planetary gears 300 of the planetary mechanism, and the sun gear shaft 500. In this embodiment, when monitoring the output shaft of the wind turbine gearbox, the mounting seat 13 is installed on the mounting box 100 of the wind turbine gearbox, and the conductive probe 11 is in contact with the outer peripheral surface of the output shaft. At this time, the insulating tube 14 is made of normal insulating material. In another embodiment, as Figure 4 As shown, when monitoring the planetary gear 300 inside the wind turbine gearbox, three monitoring modules 1 need to be configured, of which two monitoring modules 1 are installed on the housing 600 of the planetary mechanism, and their conductive probes 11 are in contact with the outer peripheral surface of the planetary frame 400, for forming a loop with the external connection through the excitation circuit; another monitoring module 1 is installed on the planetary frame 400, and its conductive probe 11 is in contact with the end face of the planetary gear 300, for introducing the shaft voltage on the planetary gear 300 to the planetary frame 400, and further exporting it through the two monitoring modules 1 on the housing 600 for measurement; it can be understood that the insulating cylinder 14 of the monitoring module 1 installed on the housing 600 is made of normal insulating material, while the monitoring module 1 on the planetary frame 400 is not provided with the insulating cylinder 14, or the insulating cylinder 14 is made of conductive material to ensure the conduction of current. In another embodiment, as Figure 4As shown, when monitoring the sun gear shaft 500 inside the wind turbine gearbox, three monitoring modules 1 need to be configured, two of which are mounted on the housing 600 of the planetary mechanism, and their conductive probes 11 are in contact with the outer peripheral surface of the planetary carrier 400, for forming a loop with the external connection through the excitation circuit; another monitoring module 1 is mounted on the planetary carrier 400, and its conductive probe 11 is in contact with the outer peripheral surface or end face of the sun gear shaft 500, for introducing the shaft voltage of the sun gear shaft 500 to the planetary carrier 400, and further exporting it through the two monitoring modules 1 on the housing 600 for measurement; it can be understood that the insulating cylinder 14 of the monitoring module 1 mounted on the housing 600 is made of normal insulating material, while the monitoring module 1 mounted on the planetary carrier 400 is not provided with the insulating cylinder 14, or the insulating cylinder 14 is made of conductive material to ensure the conduction of current. Furthermore, the monitoring module 1 also includes a temperature sensor, and the probe of the temperature sensor is arranged on the conductive probe 11; and / or, the monitoring module 1 also includes a vibration sensor, and the probe of the vibration sensor is arranged on the conductive probe 11. The probe of the temperature sensor can monitor the temperature of the rotating body 200 and transmit an electrical signal to the control center, so that the control center can monitor the temperature of the rotating body 200 in real time and promptly detect temperature abnormalities on the rotating body 200. The probe of the vibration sensor can monitor the vibration of the rotating body 200 and transmit an electrical signal to the control center, so that the control center can monitor the vibration of the rotating body 200 in real time; in this embodiment, a temperature sensor and a vibration sensor are simultaneously provided in the monitoring module 1. The temperature sensor and the vibration sensor cooperate with each other, which can facilitate the staff to promptly detect abnormal working conditions of the rotating body 200, thereby reducing the failure rate of the wind turbine gearbox.

[0048] This embodiment also provides a wind turbine gearbox, comprising a mounting housing 100, a rotating body 200, and the aforementioned shaft voltage monitoring device, wherein at least a portion of the rotating body 200 is disposed within the mounting housing 100; a monitoring port is provided on the mounting housing 100, and a monitoring module 1 is disposed at the monitoring port. In this embodiment, the wind turbine gearbox has a simple structure and is easy to operate. It is capable of performing real-time voltage monitoring of the rotating body 200 within the mounting housing 100. By providing at least two monitoring modules 1 and an elastic member 12, the reliability of the contact between the conductive probe 11 and the rotating body 200 and the connectivity of the conductive circuit are ensured, thereby reducing the failure rate of the wind turbine gearbox caused by excessive shaft voltage. Specifically, the monitoring port can be provided on the main body of the mounting housing 100 or on an end cap of the mounting housing 100 corresponding to the position where the rotating body 200 extends. Any suitable method is not limited here, as long as it can ensure that the conductive probe 11 can contact the rotating body 200 within.

[0049] Furthermore, the monitoring module 1 also includes a temperature sensor, a vibration sensor and a displacement sensor. The probes of the temperature sensor, vibration sensor and displacement sensor are all arranged on the conductive probe 11. Therefore, the wind turbine gearbox can simultaneously monitor the temperature, vibration and displacement of the rotating body 200 in real time, thereby obtaining a more comprehensive operating condition of the rotating body 200 and timely discovering operating abnormalities of the wind turbine gearbox, thereby further reducing the failure rate of the wind turbine gearbox.

[0050] In this embodiment, if Figure 1 and Figure 2 As shown, there are two monitoring ports and two monitoring modules 1, and the two monitoring ports are spaced apart along the circumference of the rotating body 200, with a monitoring module 1 being provided at each monitoring port. Specifically, two monitoring ports are provided on the mounting box 100 along the circumference, and both monitoring ports are provided facing the rotating body 200 inside the mounting box 100. The two monitoring modules 1 are provided in a one-to-one correspondence with the two monitoring ports. The mounting seat 13 is installed at the monitoring port, and the two ends of the excitation circuit are electrically connected to the two conductive probes 11, thereby forming a conductive loop between the two conductive probes 11, the rotating body 200, and the excitation circuit. The excitation circuit can input an excitation current into the conductive loop. Furthermore, a relay and a power resistor are provided on the excitation circuit. If the shaft voltage in the conductive loop reaches a set threshold, the control center will turn on the conductive loop through the relay, and the current generated by the shaft voltage will be consumed and discharged in the form of heat through the power resistor, thereby ensuring the safety of the wind turbine gearbox during operation. It can be understood that in most wind turbine gearboxes, a shaft sleeve is provided at the mating portion between the rotating body 200 and the mounting box 100 to reduce the friction between the rotating body 200 and the mounting box 100, so that the rotating body 200 can rotate smoothly relative to the mounting box 100. The end of the conductive probe 11 provided here abuts against the shaft sleeve. Since the shaft sleeve is made of conductive metal, the monitoring of the shaft voltage on the shaft sleeve by the conductive probe 11 is equivalent to monitoring the shaft voltage on the rotating body 200.

[0051] The connection method between the mounting base 13 and the monitoring port can be set according to actual needs, as long as the mounting base 13 is stably connected to the mounting box 100. For example, the inner wall surface of the monitoring port is provided with threads, and the outer peripheral surface of the mounting base 13 is also provided with threads. The mounting base 13 is screwed to the monitoring port, which has a simple structure and is easy to disassemble and assemble, and has strong practicality and convenience.

[0052] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A shaft voltage monitoring device, characterized in that: include: At least two monitoring modules (1), the monitoring modules (1) comprising a conductive probe (11), an elastic member (12) and a mounting seat (13), the conductive probe (11) being inserted into the mounting seat (13), the elastic member (12) applying an elastic force to the conductive probe (11) so that an end of the conductive probe (11) can abut against a rotating body (200) to be monitored; An excitation circuit is used to connect the two monitoring modules (1), one end of the excitation circuit is electrically connected to one of the conductive probes (11), and the other end of the excitation circuit is electrically connected to the other conductive probe (11).

2. The shaft voltage monitoring device according to claim 1, characterized in that: The mounting seat (13) is provided with a mounting hole, the conductive probe (11) is passed through the mounting hole, and the elastic member (12) is arranged in the mounting hole.

3. The shaft voltage monitoring device according to claim 2, characterized in that: The monitoring module (1) further comprises an insulating tube (14), wherein the insulating tube (14) is fixedly sleeved on the conductive probe (11) and penetrates the mounting hole.

4. The shaft voltage monitoring device according to claim 3, characterized in that: A sealing ring (15) is provided between the inner wall surface of the mounting hole and the insulating cylinder (14).

5. The shaft voltage monitoring device according to claim 3, characterized in that: The mounting hole is a stepped hole, one end of the elastic member (12) abuts against the stepped surface of the mounting hole, and the other end of the elastic member (12) abuts against the limiting portion (142) of the insulating tube (14).

6. The shaft voltage monitoring device according to claim 3, characterized in that: A stopper (141) is provided on the insulating cylinder (14), and the stopper (141) is located outside the mounting hole and can abut against the mounting seat (13) along the moving direction of the insulating cylinder (14).

7. The shaft voltage monitoring device according to any one of claims 1 to 6, characterized in that: The monitoring module (1) further comprises a temperature sensor, wherein a probe of the temperature sensor is arranged on the conductive probe (11); And / or, the monitoring module (1) further comprises a vibration sensor, a probe of the vibration sensor being arranged on the conductive probe (11).

8. Wind power gearbox, characterized in that, The invention comprises an installation box (100), a rotating body (200) and the shaft voltage monitoring device according to any one of claims 1 to 7, wherein at least a portion of the rotating body (200) is arranged inside the installation box (100), a monitoring port is opened on the installation box (100), and the monitoring module (1) is arranged at the monitoring port.

9. The wind turbine gearbox according to claim 8, characterized in that: Two monitoring ports and two monitoring modules (1) are provided, the two monitoring ports are spaced apart along the circumference of the rotating body (200), and one monitoring module (1) is provided at each monitoring port.

10. The wind turbine gearbox according to claim 8, characterized in that: The mounting seat (13) is threadedly connected to the monitoring port.

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