Oil level monitoring device and transformer

Abstract

The utility model provides an oil level monitoring device and transformer, oil level monitoring device installs inside the oil tank casing, including guide rod, floater subassembly, waveguide pole and cleaning component, guide rod extends along the height direction of oil tank casing, floater subassembly includes floater body and permanent magnet, the floater body sleeve joint is in the outer periphery of guide rod, and can slide along the length direction of guide rod relative to guide rod, permanent magnet is fixed in the inside of floater body and surrounds the outer periphery of guide rod, waveguide pole includes the pole core made of magnetostrictive material, extends along the height direction of oil tank casing and is set apart with guide rod with the distance of prearranged, cleaning component includes eccentric weight and vibration motor, fixedly arranged in the bottom of the inside of floater body, respectively located the opposite sides of guide rod. Not only can realize the measurement of oil level, and vibration motor power on work, can drive floater body vibration, through vibration to clean the impurity that deposits on floater body surface, guarantees the precision of oil level measurement.

Description

Technical Field

[0001] This utility model belongs to the field of oil level monitoring technology, and specifically relates to an oil level monitoring device and a transformer. Background Technology

[0002] As a key piece of equipment in the power system, the operating status of transformers directly affects the stability and security of the power grid. Oil-immersed transformers achieve heat dissipation and insulation through insulating oil, and the oil level is an important parameter reflecting the transformer's operating status.

[0003] Traditional oil level monitoring technology typically uses pointer-type oil level gauges. These gauges work by moving a lever through the up-and-down movement of a float or diaphragm, which in turn converts linear motion into rotational motion via a gear transmission mechanism. This drives the pointer to display the oil level. However, the gear transmission mechanism needs to be immersed in transformer oil. Over long-term operation, transformer oil produces impurities such as carbides and metal debris, which accumulate on the gear transmission mechanism and the float or diaphragm of the oil level gauge. This causes wear and jamming of the mechanical parts of the gauge and increases the weight of the float or diaphragm, affecting the accuracy of the oil level output. Furthermore, each maintenance requires draining the oil and replacing the seals, resulting in high maintenance costs and a risk of oil leakage.

[0004] To address the aforementioned issues, the existing patent CN205642557U discloses a magnetostrictive liquid level measuring device. This device eliminates the gear transmission mechanism and uses a magnetic float of the oil surface attached to a waveguide rod. Utilizing the magnetostrictive principle, it achieves oil level measurement, solving the problem of impurities depositing on the gear transmission mechanism of the oil level gauge, thus affecting the accuracy of the oil level output. However, impurities still accumulate on the float, increasing its weight and resulting in low oil level output accuracy, requiring regular cleaning and maintenance. Utility Model Content

[0005] The purpose of this invention is to solve the problem in existing measuring devices where impurities such as carbides and metal debris accumulate on the float during long-term operation of transformer oil, increasing the float's weight, affecting the accuracy of oil level output, and requiring regular cleaning and maintenance.

[0006] To solve the above-mentioned technical problems, this utility model discloses an oil level monitoring device for installation inside an oil tank shell, comprising: a guide rod extending along the height direction of the oil tank shell, with its two ends fixedly connected to the top and bottom walls of the oil tank shell respectively; a float assembly including a float body and a permanent magnet, the float body being sleeved on the outer periphery of the guide rod and slidable relative to the guide rod along its length direction, the permanent magnet being fixed inside the float body and surrounding the outer periphery of the guide rod; a waveguide rod fixedly disposed inside the oil tank shell and extending along the height direction of the oil tank shell, with the waveguide rod and the guide rod spaced apart at a preset distance, the waveguide rod including a rod core made of magnetostrictive material; and a cleaning assembly including an eccentric counterweight and a vibration motor, the eccentric counterweight and the vibration motor being fixedly disposed at the bottom inside the float body and located on opposite sides of the guide rod, the vibration motor being used to drive the float assembly to vibrate.

[0007] The above technical solution involves setting a waveguide rod and a guide rod, both with a core made of magnetostrictive material, at a predetermined distance, extending along the height of the oil tank housing. The float body is fitted around the outer periphery of the guide rod, and a permanent magnet is fixed inside the float body and surrounds the outer periphery of the guide rod. A cleaning assembly including a vibration motor is also provided. The vibration motor is located at the bottom inside the float body, enabling not only oil level measurement but also, when energized, causing the float body to vibrate, thus cleaning impurities deposited on its surface and ensuring accurate oil level measurement. Furthermore, eccentric counterweights and the vibration motor are positioned on opposite sides of the guide rod to balance the weight of the vibration motor, ensuring the float assembly remains unaffected by its movement with the oil. Moreover, the float body is fitted around the outer periphery of the guide rod, rather than the waveguide rod, preventing changes in the magnetostrictive material of the waveguide rod caused by the vibration motor's operation, which could affect measurement accuracy.

[0008] According to another specific embodiment of the present invention, the oil level monitoring device disclosed in this embodiment has an oleophobic layer coated on the outer surface of the float body, and a plurality of grooves spaced apart are provided on the outer surface of the oleophobic layer.

[0009] By employing the above technical solution, an oleophobic layer is coated on the outer surface of the float body, enabling the outer surface of the float body to resist oil stains and preventing oil from penetrating into the interior of the float body. Multiple grooves spaced apart are then formed on the outer surface of the oleophobic layer, further utilizing biomimetic principles to achieve the oil-resistant effect on the outer surface of the float body.

[0010] According to another specific embodiment of the present invention, the oil level monitoring device disclosed in this embodiment of the present invention further includes a limiting part, which is fixed to one end of the guide rod near the top wall of the oil tank shell.

[0011] By adopting the above technical solution, a limiting part is set at one end of the guide rod near the top wall of the oil tank shell, which can prevent the float body from colliding with the top wall of the oil tank shell when there is a lot of oil inside the oil tank shell, thereby affecting the service life of both.

[0012] According to another specific embodiment of the present invention, the oil level monitoring device disclosed in this embodiment further includes an insulating layer and a protective layer on the waveguide rod. The insulating layer covers the outer periphery of the rod core, and the protective layer covers the outer periphery of the insulating layer.

[0013] By adopting the above technical solution, an insulating layer and a protective layer are set. The insulating layer covers the outer periphery of the rod core, and the protective layer covers the outer periphery of the insulating layer. This can protect the rod core made of magnetostrictive material and prevent it from being contaminated by oil, thereby affecting the accuracy of the measurement.

[0014] According to another specific embodiment of the present invention, the oil level monitoring device disclosed in this embodiment has a preset distance of 3mm to 8mm.

[0015] Using the above technical solution, the waveguide rod and the guide rod are set at a preset distance of 3mm to 8mm, which can ensure that the axial magnetic field generated by the permanent magnet and the circumferential magnetic field generated after the waveguide rod is energized can be superimposed to form a helical magnetic field, thereby generating a torsional wave (i.e., a reflected wave), which can further enable the measurement of oil level.

[0016] According to another specific embodiment of the present invention, the oil level monitoring device disclosed in this embodiment further includes a pulse generator, an echo receiver, and a controller. The controller is communicatively connected to the pulse generator and the echo receiver, respectively. The pulse generator and the echo receiver are fixed to the top of the waveguide rod. The oil level monitoring device also includes a protective housing, which is fixed to the inner wall of the oil tank housing and includes a lower housing and an upper cover. The upper cover is sealed and fixedly connected to the lower housing to form a receiving cavity together. The controller is fixed in the receiving cavity of the protective housing.

[0017] Using the above technical solution, the pulse generator and echo receiver are fixed to the top of the waveguide rod, and the controller is communicatively connected to both the pulse generator and the echo receiver. The controller can control the pulse generator to send pulse current to the waveguide rod, and control the echo receiver to receive the torsional wave generated by the superposition of the circumferential magnetic field generated by the waveguide rod and the axial magnetic field of the permanent magnet. The controller calculates the corresponding oil level by calculating the time difference between sending the pulse current and receiving the torsional wave. The controller is fixed in a sealed cavity within a protective housing, which avoids the influence of the oil on the controller and ensures normal oil level measurement.

[0018] According to another specific embodiment of the present invention, the oil level monitoring device disclosed in this embodiment has an upper cover and a lower housing sealed together by a sealing assembly. The sealing assembly includes a fluororubber O-ring, a copper powder sintered ring, and an organosilicon sealant arranged sequentially from the outside to the inside and surrounding the outer periphery of the receiving cavity. A first annular sealing groove is provided on the side of the lower housing facing the upper cover or the side of the upper cover facing the lower housing, and the fluororubber O-ring is fixed in the first annular sealing groove. A second annular sealing groove is provided on the side of the lower housing facing the upper cover or the side of the upper cover facing the lower housing. The second annular sealing groove is located on the side of the first annular sealing groove closer to the receiving cavity. The copper powder sintered ring is fixed in the second annular sealing groove, and the fluororubber O-ring is closer to the oil in the oil tank housing than the copper powder sintered ring. The organosilicon sealant is provided on the side of the lower housing facing the upper cover or the side of the upper cover facing the lower housing.

[0019] By adopting the above technical solution, the fluororubber O-ring can intercept liquid oil, the copper powder sintered ring can block gaseous oil molecules, and the silicone sealant can further seal the surface. By setting the above triple seal, the sealing performance between the upper cover and the lower shell can be guaranteed.

[0020] According to another specific embodiment of the present invention, the oil level monitoring device disclosed in this embodiment of the present invention further includes a wireless transmission module, which is fixed in the receiving cavity and electrically connected to the controller.

[0021] By adopting the above technical solution, the measured oil level data can be wirelessly transmitted to a remote terminal by setting up a wireless transmission module, thereby realizing remote monitoring and reducing the frequency of manual inspections.

[0022] According to another specific embodiment of the present invention, the oil level monitoring device disclosed in this embodiment of the present invention further includes a temperature sensor, which is fixed on the inner wall of the oil tank housing and is communicatively connected to the controller.

[0023] By adopting the above technical solution, a temperature sensor can be installed inside the oil tank housing to obtain the oil temperature information of the oil tank housing. The temperature sensor is connected to the controller, and the controller can further analyze the influence of temperature on oil level based on the oil temperature information and the measured oil level.

[0024] The present invention also discloses a transformer, comprising: an oil tank housing and an oil level monitoring device as described above, wherein the oil level monitoring device is installed inside the oil tank housing.

[0025] The beneficial effects of this utility model are as follows:

[0026] This invention provides an oil level monitoring device and a transformer incorporating the device. The oil level monitoring device is installed inside an oil tank casing and includes a guide rod, a float assembly, a waveguide rod, and a cleaning assembly. The waveguide rod, with a core made of magnetostrictive material, is spaced at a predetermined distance from the guide rod, and both extend along the height of the oil tank casing. The float assembly includes a float body and a permanent magnet. The float body is fitted around the outer periphery of the guide rod, and the permanent magnet is fixed inside the float body and surrounds the outer periphery of the guide rod. A cleaning assembly including a vibration motor is also provided. The vibration motor is located at the bottom inside the float body. It not only measures the oil level but also, when energized, drives the float body to vibrate, cleaning impurities deposited on the surface of the float body and ensuring the accuracy of the oil level measurement. Furthermore, an eccentric counterweight and the vibration motor are located on opposite sides of the guide rod to balance the weight of the vibration motor, ensuring that the float assembly is not affected by the vibration motor when moving up and down with the oil. Furthermore, the float body is fitted around the outer periphery of the guide rod rather than the outer periphery of the waveguide rod, which can prevent changes in the magnetostrictive material of the waveguide rod from affecting the measurement accuracy when the vibration motor is powered on. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the oil level monitoring device provided in an embodiment of the present invention;

[0028] Figure 2 A top view of the oil level monitoring device provided in this embodiment of the utility model;

[0029] Figure 3 for Figure 2 Sectional view of AA;

[0030] Figure 4 for Figure 3 A magnified view of position C in the middle;

[0031] Figure 5 for Figure 2 BB section view;

[0032] Figure 6 for Figure 5 A magnified view of position D in the middle;

[0033] Figure 7 A connection block diagram of the controller-related components in the oil level monitoring device provided in this embodiment of the utility model.

[0034] Explanation of reference numerals in the attached figures:

[0035] 10. Tank housing; 100. Guide rod; 110. Limiting part; 200. Float assembly; 210. Float body; 220. Permanent magnet; 230. Oleophobic layer; 300. Waveguide rod; 400. Cleaning component; 410. Eccentric counterweight; 420. Vibration motor; 500. Pulse generator; 600. Echo receiver; 700. Controller; 800. Protective housing; 810. Lower housing; 820. Top cover; 830. Receiving cavity; 840. Fluororubber O-ring; 850. Copper powder sintered ring; 860. Silicone sealant; 910. Wireless transmission module; 920. Temperature sensor. Detailed Implementation

[0036] As a key piece of equipment in the power system, the operating status of transformers directly affects the stability and security of the power grid. Oil-immersed transformers achieve heat dissipation and insulation through insulating oil, and the oil level is an important parameter reflecting the transformer's operating status.

[0037] Traditional oil level monitoring technology typically uses pointer-type oil level gauges. These gauges work by moving a lever through the up-and-down movement of a float or diaphragm, which in turn converts linear motion into rotational motion via a gear transmission mechanism. This drives the pointer to display the oil level. However, the gear transmission mechanism needs to be immersed in transformer oil. Over long-term operation, transformer oil produces impurities such as carbides and metal debris, which accumulate on the gear transmission mechanism and the float or diaphragm of the oil level gauge. This causes wear and jamming of the mechanical parts of the gauge and increases the weight of the float or diaphragm, affecting the accuracy of the oil level output. Furthermore, each maintenance requires draining the oil and replacing the seals, resulting in high maintenance costs and a risk of oil leakage.

[0038] The existing patent with publication number CN205642557U discloses a magnetostrictive liquid level measuring device, which eliminates the gear transmission mechanism and uses a magnetic float of the oil surface sleeved on the waveguide rod. It uses the magnetostrictive principle to realize the measurement of oil level and solves the problem of impurities depositing on the gear transmission mechanism of the oil level gauge, thus affecting the accuracy of oil level output. However, impurities still deposit on the float, which increases the weight of the float and results in low oil level output accuracy, requiring regular cleaning and maintenance.

[0039] To address the aforementioned problems in the prior art, this utility model provides an oil level monitoring device and a transformer equipped with the oil level monitoring device. The oil level monitoring device includes a cleaning component comprising a vibration motor, which is located at the bottom of the float body. This component not only measures the oil level but also, when powered on, drives the float body to vibrate, thereby cleaning impurities deposited on the surface of the float body and ensuring the accuracy of the oil level measurement.

[0040] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0041] Example 1

[0042] This utility model provides an oil level monitoring device, such as... Figures 1-6 As shown, for installation inside the fuel tank housing 10, it includes: a guide rod 100, a float assembly 200, a waveguide rod 300, and a cleaning assembly 400.

[0043] Among them, such as Figure 1 and Figure 3 As shown, the guide rod 100 is along the height direction of the oil tank housing 10 ( Figure 1 and Figure 3 It extends in the Y direction and its two ends are fixedly connected to the top and bottom walls of the tank housing 10, respectively.

[0044] It should be noted that, in order to facilitate observation of the specific structure of the oil level monitoring device inside the oil tank housing 10, Figure 1 and Figure 2 The top wall of the fuel tank housing 10 is concealed.

[0045] like Figure 4 As shown, the float assembly 200 includes a float body 210 and a permanent magnet 220. The float body 210 is sleeved on the outer periphery of the guide rod 100 and can move along the length direction of the guide rod 100. Figure 4 The permanent magnet 220 slides relative to the guide rod 100 in the Y direction, and is fixed inside the float body 210 and surrounds the outer periphery of the guide rod 100.

[0046] It should be noted that in this embodiment, the float body 210 is filled with polyurethane foam, allowing the float assembly 200 to move up and down with changes in oil level. The permanent magnet 220 is annular, surrounding the outer periphery of the guide rod 100, and its fixed connection with the float body 210 includes, but is not limited to, snap-fitting and bonding. Specifically, the permanent magnet 220 is an axially magnetized neodymium iron boron magnetic ring, capable of generating an axial magnetic field with a surface magnetic field strength ≥0.3T.

[0047] like Figure 1 As shown, the waveguide rod 300 is fixedly installed inside the oil tank housing 10, and along the height direction of the oil tank housing 10. Figure 1 Extending in the Y direction, and as shown Figure 2 The waveguide rod 300 and the guide rod 100 shown are spaced apart by a preset distance h. The waveguide rod 300 includes a rod core made of magnetostrictive material.

[0048] It should be noted that the waveguide rod 300 extends along the height direction of the tank housing 10, and its axis is parallel to the magnetization direction of the permanent magnet 220. The waveguide rod 300 and the guide rod 100 are spaced apart by a preset distance h. It is necessary to ensure that the axial magnetic field generated by the permanent magnet 220 and the circumferential magnetic field generated by the waveguide rod 300 after being energized can be superimposed to form a helical magnetic field. Since the waveguide rod 300 includes a rod core made of magnetostrictive material, the waveguide rod 300 will undergo magnetostrictive deformation, generating torsional waves (i.e., reflected waves, for example...). Figure 1 The location E in the diagram allows for further measurement of the oil level. In one specific embodiment, the preset distance h ranges from 3mm to 8mm. The magnetostrictive material is specifically an iron-nickel alloy.

[0049] In one embodiment of the present invention, the waveguide rod 300 further includes an insulating layer and a protective layer, the insulating layer covering the outer periphery of the rod core, and the protective layer covering the outer periphery of the insulating layer.

[0050] Specifically, an insulating layer and a protective layer are provided. The insulating layer covers the outer periphery of the rod core, and the protective layer covers the outer periphery of the insulating layer. This protects the rod core, which is made of magnetostrictive material, from oil contamination, thus preventing it from affecting the measurement accuracy. It should be noted that the insulating layer can be made of polytetrafluoroethylene (PTFE), and the protective layer can be made of stainless steel.

[0051] like Figure 4 As shown, the cleaning assembly 400 includes an eccentric counterweight 410 and a vibration motor 420. The eccentric counterweight 410 and the vibration motor 420 are fixedly installed at the bottom inside the float body 210 and are located on opposite sides of the guide rod 100. The vibration motor 420 is used to drive the float assembly 200 to vibrate.

[0052] Specifically, the eccentric counterweight 410 and the vibration motor 420 are located on opposite sides of the guide rod 100, and their weights are similar. This balances the weight of the vibration motor 420, ensuring that the float assembly 200 is not affected by the vibration motor 420 when moving up and down with the oil. Furthermore, when the vibration motor 420 is powered on, it drives the float body 210 to vibrate, cleaning impurities deposited on the surface of the float body 210 and ensuring the accuracy of oil level measurement.

[0053] It should be noted that the float body 210 is sleeved on the outer periphery of the guide rod 100 rather than the outer periphery of the waveguide rod 300. This avoids changes in the magnetostrictive material of the waveguide rod 300 when the vibration motor 420 is energized, which would affect the measurement accuracy. A connecting through-hole is also provided on the float body 210. The wires of the vibration motor 420 pass through the connecting through-hole to connect to the external power supply, and the wires are sealed to the connecting through-hole.

[0054] In one embodiment of this utility model, such as Figure 4 As shown, the outer surface of the float body 210 is coated with an oleophobic layer 230, and the outer surface of the oleophobic layer 230 has multiple grooves spaced apart. Coating with the oleophobic layer 230 enables the outer surface of the float body 210 to have an oil-resistant effect, preventing oil from penetrating into the interior of the float body 210. Furthermore, the multiple grooves on the outer surface of the oleophobic layer 230 form an oil-resistant core structure through biomimetic principles, and its oil-resistant effect far exceeds that of traditional flat coatings.

[0055] It should be noted that in this embodiment, the oleophobic layer 230 is made of polytetrafluoroethylene and has a thickness of 50±5μm. Multiple grooves can be evenly distributed or unevenly distributed on the outer surface of the oleophobic layer 230. The groove depth ranges from 20μm to 30μm, and the groove length and width range from 50μm to 80μm.

[0056] In one embodiment of this utility model, such as Figure 1 As shown, the oil level monitoring device also includes a limiting part 110, which is fixed to one end of the guide rod 100 near the top wall of the oil tank housing 10.

[0057] It should be noted that the limiting part 110 can be a limiting ring that is sleeved and fixed to the outer periphery of the guide rod 100, or a protrusion that protrudes from the outer periphery of the guide rod 100, or other structures that can limit the contact between the float body 210 and the top wall of the tank housing 10. No specific limitation is made in this embodiment, as long as it can prevent the float body 210 from colliding with the top wall of the tank housing 10 when there is a lot of oil inside the tank housing 10, thereby affecting the service life of both.

[0058] In one embodiment of this utility model, such as Figure 5 , Figure 6 and Figure 7 As shown, the oil level monitoring device also includes a pulse generator 500, an echo receiver 600, and a controller 700. The controller 700 is communicatively connected to both the pulse generator 500 and the echo receiver 600. Figure 5 As shown, the pulse generator 500 and the echo receiver 600 are fixed to the top of the waveguide rod 300.

[0059] Specifically, changes in oil level cause the float assembly 200 to move up and down. The permanent magnet 220 inside the float assembly 200 continuously generates an axial magnetic field. The controller 700 can control the pulse generator 500 to send pulse current to the waveguide rod 300. The current causes the waveguide rod 300 to generate a circumferential magnetic field, which superimposes with the axial magnetic field of the permanent magnet 220 to form a spiral magnetic field, causing the waveguide rod 300 to undergo magnetostrictive deformation and generate a torsional wave (i.e., a reflected wave). The torsional wave propagates to both ends of the waveguide rod 300 at a fixed speed. The echo receiver 600 fixed to the top of the waveguide rod 300 receives the torsional wave. Based on the time interval between the pulse current sent by the pulse generator 500 to the waveguide rod 300 and the torsional wave received by the echo receiver 600, and combined with the fixed propagation speed of the torsional wave on the waveguide rod 300, the controller 700 can determine the vertical height of the permanent magnet 220 (i.e., the float assembly 200), thereby realizing the measurement of oil level. In other words, different oil levels result in different vertical heights of the permanent magnet 220, different positions of the axial magnetic field it generates, different positions of the spiral magnetic field formed by the superposition of the circumferential magnetic field generated by the waveguide rod 300 and the axial magnetic field of the permanent magnet 220, different positions of the torsional wave generated by the magnetostrictive deformation of the waveguide rod 300, and different time intervals between sending pulse current and receiving torsional wave. As a result, the measured oil level is also different, thus achieving the oil level measurement.

[0060] It should be noted that the controller 700 can also communicate with the vibration motor 420. When the transformer is in normal operation, the oil level inside the oil tank housing 10 will not change in a short time. The controller 700 can control the periodic power supply to the vibration motor 420 to clean the impurities deposited on the surface of the float body 210.

[0061] In one embodiment of this utility model, such as Figure 1 and Figure 6 As shown, the oil level monitoring device also includes a protective housing 800, which is fixed to the inner wall of the oil tank housing 10 and includes a lower housing 810 and an upper cover 820. The upper cover 820 is sealed and fixedly connected to the lower housing 810 to form a receiving cavity 830. The controller 700 is fixed in the receiving cavity 830 of the protective housing 800, which can prevent the oil from affecting the controller 700 and ensure that the oil level can be measured normally.

[0062] It should be noted that the fixed connection method between the upper cover 820 and the lower housing 810 includes, but is not limited to, threaded connection (e.g., Figure 6 As shown, the connection can be bolted, snap-fit, etc., and in order to achieve a sealed connection, sealing components such as sealing rings are also required at the connection point.

[0063] In one embodiment of this utility model, such as Figure 6As shown, the upper cover 820 and the lower housing 810 are sealed together by a sealing assembly. The sealing assembly includes fluororubber O-rings 840, copper powder sintered rings 850, and silicone sealant 860, which are arranged sequentially from the outside to the inside and surround the outer periphery of the receiving cavity 830. A first annular sealing groove is provided on the side of the lower housing 810 facing the upper cover 820 or on the side of the upper cover 820 facing the lower housing 810. The fluororubber O-rings 840 are fixed in the first annular sealing groove. A second annular sealing groove is provided on one side of the 20 or the side of the upper cover 820 facing the lower housing 810. The second annular sealing groove is located on the side of the first annular sealing groove near the receiving cavity 830. The copper powder sintered ring 850 is fixed in the second annular sealing groove, and the fluororubber O-ring 840 is closer to the oil in the oil tank housing 10 than the copper powder sintered ring 850. The silicone sealant 860 is provided on the side of the lower housing 810 facing the upper cover 820 or the side of the upper cover 820 facing the lower housing 810.

[0064] It should be noted that the fluororubber O-ring 840 is the first layer of seal, which can intercept liquid oil. The copper powder sintered ring 850 is the second layer of seal, with a thickness of 2mm, which can block gaseous oil molecules. The silicone sealant 860 is the third layer of seal, which enhances the sealing effect. By setting up three layers of seals, the actual sealing performance of the protective shell 800 at an oil temperature of 85℃ is such that the oil vapor permeation is <0.01g / year.

[0065] In one embodiment of this utility model, such as Figure 6 and Figure 7 As shown, the oil level monitoring device also includes a wireless transmission module 910, which is fixed in the receiving cavity 830 and electrically connected to the controller 700.

[0066] It should be noted that in this embodiment, the wireless transmission module 910 includes a LoRa chip, an NB-IoT module, and an antenna switching circuit, and has two radio frequency switches. By setting up the wireless transmission module 910, the measured oil level data can be wirelessly transmitted to a remote terminal, enabling remote monitoring and reducing the frequency of manual inspections. To better shield against electromagnetic interference and prevent oil and gas infiltration, an electronic compartment partition can also be installed in the containment cavity 830 to separate the wireless transmission module 910 and the controller 700.

[0067] In one embodiment of this utility model, such as Figure 1 and Figure 7 As shown, the oil level monitoring device also includes a temperature sensor 920, which is fixed to the inner wall of the oil tank housing 10 and is communicatively connected to the controller 700.

[0068] Specifically, by installing a temperature sensor 920 inside the oil tank housing 10, the oil temperature information of the oil tank housing 10 can be obtained. The temperature sensor 920 is connected to the controller 700. The controller 700 can further analyze the influence of temperature on oil level based on the oil temperature information and the measured oil level.

[0069] Example 2

[0070] This utility model also provides a transformer, including: an oil tank housing 10 and the oil level monitoring device in Embodiment 1, wherein the oil level monitoring device is installed inside the oil tank housing 10.

[0071] Specifically, a cleaning component 400, including a vibration motor 420, is installed in the oil level monitoring device. The vibration motor 420 is located at the bottom inside the float body 210. When the vibration motor 420 is powered on, it can drive the float body 210 to vibrate. The vibration cleans the impurities deposited on the surface of the float body 210, ensuring the accuracy of oil level measurement.

[0072] It should be noted that, in addition to the specific embodiments described above, those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Although the description of this utility model will be presented in conjunction with preferred embodiments, this does not mean that the features of this utility model are limited to that embodiment. On the contrary, the purpose of describing the utility model in conjunction with the embodiments is to cover other options or modifications that may be derived from the claims of this utility model. To provide a deep understanding of this utility model, many specific details will be included in the following description. This utility model may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this utility model, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0073] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0074] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.

[0075] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0076] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0077] Although the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions. Those skilled in the art can make various changes in form and detail, including some simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. An oil level monitoring device for installation inside an oil tank housing, characterized by, include: A guide rod extends along the height direction of the fuel tank housing, and its two ends are fixedly connected to the top wall and bottom wall of the fuel tank housing, respectively. A float assembly, comprising a float body and a permanent magnet, wherein the float body is sleeved on the outer periphery of the guide rod and can slide relative to the guide rod along the length direction of the guide rod, and the permanent magnet is fixed inside the float body and surrounds the outer periphery of the guide rod; A waveguide rod is fixedly disposed inside the fuel tank housing and extends along the height direction of the fuel tank housing. The waveguide rod and the guide rod are spaced apart by a preset distance. The waveguide rod includes a rod core made of magnetostrictive material. The cleaning assembly includes an eccentric counterweight and a vibration motor. The eccentric counterweight and the vibration motor are fixedly disposed at the bottom of the interior of the float body and are respectively located on opposite sides of the guide rod. The vibration motor is used to drive the float assembly to vibrate.

2. The oil level monitoring device of claim 1, wherein, The outer surface of the float body is coated with an oleophobic layer, and the outer surface of the oleophobic layer is provided with a plurality of grooves spaced apart.

3. The oil level monitoring device of claim 1, wherein, The oil level monitoring device also includes a limiting part, which is fixed to one end of the guide rod near the top wall of the oil tank housing.

4. The oil level monitoring device of claim 1, wherein, The waveguide rod also includes an insulating layer and a protective layer. The insulating layer covers the outer periphery of the rod core, and the protective layer covers the outer periphery of the insulating layer.

5. The oil level monitoring device as described in claim 1, characterized in that, The preset distance is 3mm to 8mm.

6. The oil level monitoring device of claim 1, wherein, The oil level monitoring device also includes a pulse generator, an echo receiver, and a controller. The controller is communicatively connected to the pulse generator and the echo receiver, respectively. The pulse generator and the echo receiver are fixed to the top of the waveguide rod. The oil level monitoring device also includes a protective housing, which is fixed to the inner wall of the oil tank housing and includes a lower housing and an upper cover. The upper cover is sealed and fixedly connected to the lower housing to form a receiving cavity together, and the controller is fixed in the receiving cavity of the protective housing.

7. An oil level monitoring device as claimed in claim 6, wherein The upper cover and the lower housing are sealed together by a sealing assembly, which includes fluororubber O-rings, copper powder sintered rings and silicone sealant arranged sequentially from the outside to the inside and surrounding the outer periphery of the receiving cavity. The lower housing is provided with a first annular sealing groove on the side facing the upper cover or the upper cover on the side facing the lower housing. The fluororubber O-ring is fixed in the first annular sealing groove. The lower housing is provided with a second annular sealing groove on the side facing the upper cover or the upper cover on the side facing the lower housing. The second annular sealing groove is located on the side of the first annular sealing groove closer to the receiving cavity. The copper powder sintered ring is fixed in the second annular sealing groove, and the fluororubber O-ring is closer to the oil in the oil tank housing than the copper powder sintered ring. The silicone sealant is applied to either the side of the lower housing facing the upper cover or the side of the upper cover facing the lower housing.

8. The oil level monitoring device as described in claim 6, characterized in that, The oil level monitoring device also includes a wireless transmission module, which is fixed in the receiving cavity and electrically connected to the controller.

9. An oil level monitoring device as claimed in any one of claims 1 to 8, wherein, The oil level monitoring device also includes a temperature sensor, which is fixed to the inner wall of the oil tank housing and is communicatively connected to the controller.

10. A transformer, characterized by include: The fuel tank housing and the fuel level monitoring device as described in any one of claims 1-9, wherein the fuel level monitoring device is installed inside the fuel tank housing.

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