A new type of power transformer oil level gauge

Abstract

This invention relates to the field of transformer oil level gauge technology, specifically a novel power transformer oil level gauge, comprising an instrument body, a measuring rod, and an annular float. The measuring rod is mounted on the instrument body, and the annular float is sleeved on the measuring rod. At least three radial centering blocks are evenly arranged in a ring on the annular float. Springs connect the radial centering blocks to the annular float, and the radial centering blocks are slidably mounted on the annular float in a horizontal direction. This invention, by elastically connecting at least three radial centering blocks to the annular float, allows the annular float to be centered using these blocks. This increases the clearance between the annular float and the measuring rod, preventing oil buildup on the measuring rod from hindering the annular float's movement. Furthermore, the constant clearance between the elastically connected radial centering blocks and the measuring rod ensures that the annular float does not sway violently due to fluid flow, thus preventing any impact on the stability of the annular float's magnetic field and guaranteeing the accuracy of the oil level gauge.

Description

Technical Field

[0001] This invention relates to the field of transformer oil level gauge technology, specifically a novel power transformer oil level gauge. Background Technology

[0002] Liquid level measurement is a crucial step in monitoring the internal insulating oil capacity of large power transformers. Accurate liquid level data is not only fundamental for assessing the transformer's thermal expansion and contraction compensation status, but also an important physical parameter for ensuring its safe operation.

[0003] Among existing liquid level measurement technologies, magnetostrictive oil level gauges are widely used in the measurement of oil conservator tanks in ultra-high voltage transformers due to their advantages such as non-contact sensing, high measurement accuracy, and ease of digital transmission. As shown in the invention patent application CN202010185831.6, entitled "A Magnetostrictive Guided Wave Liquid Level Gauge for High-Temperature Liquids," a ring-shaped float sliding along a measuring rod senses the liquid level height. When a current pulse is passed through the waveguide wire inside the measuring rod, the current magnetic field interacts with the permanent magnetic field of the float, generating a torsional wave signal based on the magnetostrictive effect. High-precision measurement of the liquid level is achieved by calculating the echo time difference. However, during operation, factors such as changes in insulating oil temperature, oil aging, and impurity deposition cause oil scale to gradually form on the surface of the measuring rod. As operating time accumulates, the oil scale layer thickens, hindering the sliding of the ring-shaped float. When oil accumulates to a certain extent, the annular float may become stuck at a certain position on the measuring rod and cannot move freely with changes in oil level, which may lead to the failure of the measurement signal or the output of a false liquid level signal. In severe cases, it may even cause false alarms or malfunctions of the protection device. Summary of the Invention

[0004] The purpose of this invention is to provide a novel power transformer oil level gauge. By elastically connecting at least three radial centering blocks to an annular float, the annular float can maintain a proper fit between itself and the measuring rod through the radial centering blocks. When oil sludge is generated, the spring can contract to increase the fit between the radial centering blocks and the measuring rod, thereby avoiding the problem of the annular float getting stuck and unable to move, which would affect the accuracy of the oil level gauge measurement.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A novel power transformer oil level gauge includes an instrument body, a measuring rod, and an annular float. The measuring rod is mounted on the instrument body, and the annular float is sleeved on the measuring rod. At least three radial centering blocks are evenly arranged in a ring on the annular float. A spring connects the radial centering blocks to the annular float, and the radial centering blocks are slidably mounted on the annular float in a horizontal direction. The annular float is provided with a dynamic locking component, which has a release block. The dynamic locking component is used to lock the radial centering blocks and releases the locking of the radial centering blocks when the buoyancy force on the annular float is greater than the gravity or less than the gravity.

[0006] By elastically connecting at least three radial centering blocks to the annular float, and with these blocks evenly arranged in a ring, the annular float can maintain its centering position by ensuring a proper fit between the centering blocks and the measuring rod. This increases the fit between the annular float and the measuring rod, preventing the float from becoming immobile due to oil buildup on the measuring rod. The constant gap between the elastically connected radial centering blocks and the measuring rod ensures that the annular float will not shake violently due to fluid flow, affecting its stability and thus guaranteeing the accuracy of the oil level gauge. Furthermore, locking the radial centering blocks with a dynamic locking mechanism maintains their position when they are not jammed by oil buildup, preventing spring deformation that could increase the gap between the radial centering blocks and the measuring rod. This further improves the stability of the annular float's magnetic field and enhances the measurement accuracy of the oil level gauge.

[0007] Preferably, the annular float has a groove, the radial centering block has a rotating support shaft, the rotating support shaft is located inside the groove, and springs are connected to both the upper and lower sides of the radial centering block, the springs being arranged in the vertical direction.

[0008] By setting a rotating support shaft, the radial centering block can rotate. The spring is arranged vertically, allowing the radial centering block to overcome both spring force and rotation. This ensures that even if the radial centering block slips or gets stuck, its rotation can still allow it to avoid oil residue, preventing the annular float from becoming stuck. The spring is vertically positioned, and by rotating the power arm, the gravity and buoyancy of the annular float can both reset the radial centering block after rotation and reset it after horizontal movement. This ensures that the clearance between the radial centering block and the measuring rod remains consistent. The radial centering block is elastically connected and can swing. When the radial centering block swings due to fluctuations in transformer oil, it scrapes against the oil residue, effectively reducing oil residue on the measuring rod and further preventing the annular float from becoming stuck.

[0009] Preferably, the dynamic locking component includes a limiting base plate and a locking mating surface. The radial centering block has a locking mating surface on the side away from the center of the annular float. The release block is slidably mounted on the annular float. The release block has a limiting base plate, and the limiting base plate has a stop plate. The stop plate mates with the locking mating surface.

[0010] When the oil level gauge is operating normally, the stop plate and the locking mating surface are on the same horizontal plane. At this time, the axial movement and rotation of the rotating support shaft will interfere with the stop plate, thereby restricting the horizontal movement and rotation of the radial centering block. When the liquid level drops and the annular float is stuck, the buoyancy of the annular float is less than its weight. At this time, the release block moves downward under the action of gravity, thereby driving the limiting plate to move downward, so that the stop plate moves below the locking mating surface. At this time, the radial centering block is released. When the liquid level rises and the annular float is stuck, the weight of the annular float is less than the buoyancy of the annular float. The release block moves upward under the action of buoyancy, so that the stop plate moves above the unlocking surface. At this time, the radial centering block is released again. Thus, the radial centering block cannot move when the oil level gauge is operating normally, and the locking of the radial centering block can be released when the annular float of the oil level gauge is stuck.

[0011] Preferably, the release block includes a buoyancy part and a positioning part. The two ends of the limiting plate are respectively connected to the buoyancy part and the positioning part. The positioning part is located above the buoyancy part. There is a compensation gap between the buoyancy part and the annular float. The positioning part is slidably connected to the annular float. The limiting plate is movably connected to the buoyancy part, and there is a movable allowance gap at the connection between the limiting plate and the buoyancy part.

[0012] The release block is divided into a buoyancy part and a positioning part. There is a compensation gap between the buoyancy part and the annular float, which can prevent the buoyancy part from getting stuck due to the generation of oil. Since the positioning part is located on the top, it cannot be submerged by transformer oil, which can avoid the interference of oil and prevent the release block from getting stuck due to the generation of oil, thus ensuring the feasibility of the dynamic locking device.

[0013] Preferably, the annular float is provided with a guide surface, the positioning part is in contact with the guide surface, the guide surface is inclined, and the stop plate is inclined in the opposite direction to the guide surface.

[0014] After prolonged use, wear and tear can cause gaps in the positioning section, and the accumulation of grease on the limiting plate and locking mating surface can lead to interference between the stop plate and the radial centering block during movement, preventing them from properly engaging with the locking mating surface. Therefore, the guide surface is tilted, so that the distance between the stop plate and the locking mating surface gradually decreases as the positioning section moves along the guide surface. At the point of maximum distance, the stop plate can be moved to a position horizontal with the locking mating surface. Since the stop plate and guide surface are tilted in opposite directions, the radial centering block can compress the stop plate during movement or rotation, causing the stop plate to push the limiting rod along the guide surface. During movement, the radial centering block pushes the stop plate along the tilt direction of the guide surface, thus reducing the clearance between the stop plate and the locking mating surface. This prevents excessive clearance between the stop plate and the locking mating surface, which could cause excessive movement of the radial centering block, reducing the swaying of the annular float and ensuring the stability of liquid level detection, thereby preventing false alarms.

[0015] Preferably, the annular float has guide surfaces on both the upper and lower sides of the guide surface. The lower guide surface is inclined upwards in the direction of the guide surface inclination, and the upper guide surface is inclined in the opposite direction to the lower guide surface. The upper and lower sides of the positioning part cooperate with the two guide surfaces respectively, and the center of gravity of the positioning part and the buoyancy part is biased towards the side of the guide surface inclination direction.

[0016] The guide surface allows the positioning part to move along the guide surface when the stop plate moves upward or downward. At this time, the gap between the stop plate and the locking mating surface is the largest. Thus, when the stop plate moves upward, it can move to the horizontal plane with the locking mating surface. When the buoyancy part rises under the action of buoyancy, since the center of gravity of the positioning part is located on the side of the inclined direction of the guide surface, the positioning part drives the limiting plate to gradually move in the inclined direction of the guide surface, thereby reducing the mating gap between the stop plate and the locking mating surface and avoiding large-amplitude shaking of the radial centering block.

[0017] Preferably, the rotating support shaft has a conical block on the side away from the center of the annular float, the conical block has a conical surface, the conical surface is inclined towards the radial centering block along the end of the rotating support shaft, and the diameter of the conical surface gradually decreases, a chip removal gap is provided between the radial centering block and the annular float, and the rotating support shaft has a chamfered surface on the side of the slide groove.

[0018] Although the radial centering block is positioned above the oil surface, an oil film will still form on its surface due to oil evaporation. The conical surface reduces the resistance of the oil film when the radial centering block moves away from the center of the annular float, preventing the radial centering block from getting stuck. It can also send the scraped oil film along the conical surface to the chip removal gap, thereby further preventing the radial centering block from getting stuck. The inclined surface reduces the contact area between the radial centering block and the side wall of the slide, reducing the movement resistance of the radial centering block.

[0019] Preferably, the radial centering block has an arc surface that mates with the measuring rod on the side near the center of the annular float, and both the upper and lower sides of the arc surface are chamfered.

[0020] The arc surface design improves the fit between the radial centering block and the measuring rod, ensuring a constant gap between them. The chamfer design, when the radial centering block rotates to the chamfer position, reduces its horizontal length relative to the rotating shaft. This allows the rotating shaft to rotate over the oil stains without horizontal movement, reducing spring deformation. The radial centering block can then move over the oil stains with a smaller swing angle. At this point, the difference between buoyancy and gravity is smaller, meaning the height difference between when the annular float is stuck and when it is not, effectively improving the accuracy of the oil level gauge measurement.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By elastically connecting at least three radial centering blocks to the annular float, and with the multiple radial centering blocks evenly arranged in a ring, the annular float can be centered by maintaining a fit clearance between the radial centering blocks and the measuring rod. This increases the fit clearance between the annular float and the measuring rod, preventing the annular float from becoming immobile due to oil buildup on the measuring rod. The constant clearance between the elastically connected radial centering blocks and the measuring rod ensures that the annular float will not shake violently due to fluid flow, thus affecting its stability and guaranteeing the accuracy of the oil level gauge.

[0022] 2. By setting a rotating support shaft, the radial centering block can rotate, while the spring is arranged vertically. This allows the radial centering block to overcome both the spring force and the spring force, thus preventing the annular float from being stuck and unable to move when the radial centering block slides or gets stuck. The radial centering block is elastically connected and can swing. When the radial centering block swings due to the fluctuation of transformer oil, it scrapes against the oil, effectively reducing the oil on the measuring rod and further preventing the annular float from getting stuck and unable to move.

[0023] 3. By setting a dynamic locking component with a release block for the locking radial centering block, the radial centering block can be kept in position when it is not stuck by oil stains. This avoids the spring deformation from increasing the gap between the radial centering block and the measuring rod, thereby further improving the stability of the annular float's magnetic field and improving the measurement accuracy of the oil level gauge. When the buoyancy force on the release block is greater than the gravity or less than the gravity, the locking of the radial centering block is released, allowing the radial centering block to move, thus preventing the annular float from getting stuck. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram showing the installation of the measuring rod of the present invention located inside the instrument body; Figure 3 This is a schematic diagram of the overall structure of the annular float of the present invention; Figure 4 for Figure 3 A sectional view; Figure 5 This is a partial structural cross-sectional view of the annular float of the present invention; Figure 6 for Figure 4 Sectional view of section AA in the middle; Figure 7 This is a schematic diagram of the radial centering block structure of the present invention; Figure 8 for Figure 7 Enlarged view of a section at point B in the middle; Figure 9 This is a partial structural schematic diagram of the release block of the present invention.

[0025] In the diagram: 1. Instrument body; 2. Measuring rod; 3. Annular float; 4. Radial centering block; 5. Spring; 6. Dynamic locking element; 61. Release block; 611. Buoyancy part; 612. Positioning part; 62. Limiting base plate; 63. Locking mating surface; 64. Stop plate; 7. Slide groove; 8. Rotary support shaft; 9. Compensation clearance; 10. Movable allowance clearance; 11. Guide surface; 12. Guide surface; 13. Conical block; 14. Chip removal clearance; 15. Inclined surface; 16. Arc surface; 17. Chamfer; 18. Display; 19. Connecting flange. Detailed Implementation

[0026] Please see Figures 1 to 9 This invention provides a novel oil level gauge for power transformers, the technical solution of which is as follows: A new type of oil level gauge for power transformers, please refer to [link / reference]. Figures 1 to 5 as well as Figure 7 , Figure 8The instrument includes a main body 1, on which a measuring rod 2, a display 18, and a connecting flange 19 are mounted. An annular float 3 is fitted onto the measuring rod 2. The waveguide wire inside the measuring rod 2 is electrically connected to the display 18. The annular float 3 has four sliding grooves 7. Four radial centering blocks 4 are arranged in a ring on the annular float 3. A rotating support shaft 8 is mounted on each radial centering block 4. The rotating support shaft 8 is slidably installed inside the sliding grooves 7. The radial centering blocks 4 are slidably installed on the sliding grooves 7 through the cooperation of the rotating support shaft 8 and the sliding grooves 7. The length of the rotating support shaft 8 is greater than the depth of the sliding groove 7, so that the radial centering blocks 4 and the annular float 3 are aligned. A chip removal gap 14 is formed between the rotating support shaft 8 and the annular float 3. A conical block 13 is provided on the side of the rotating support shaft 8 away from the center of the annular float 3. The conical block 13 has a conical surface, which is inclined towards the radial centering block 4 along the end of the rotating support shaft 8, and the diameter of the conical surface gradually decreases. A chamfered surface 15 is provided on the side of the rotating support shaft 8 located in the slide groove 7. An arc surface 16 that cooperates with the measuring rod 2 is provided on the side of the radial centering block 4 near the center of the annular float 3. Both the upper and lower sides of the arc surface 16 have chamfers 17. A dynamic locking element 6 is provided on the annular float 3. Springs 5 ​​are connected between the radial centering block 4 and the annular float 3 on both sides. 5. Vertical setting; During operation, the springs 5 ​​on both sides have the same elastic force, keeping the radial centering block 4 in a horizontal position. When the annular float 3 moves up and down under the action of buoyancy or gravity and gets stuck due to the action of oil, the spring 5 deforms, causing the radial centering block 4 to rotate and push the radial centering block 4 to move horizontally. This allows the radial centering block 4 to move over the oil, thus avoiding jamming. The setting of the elastic radial centering block 4 can increase the gap between other parts of the annular float 3 and the measuring rod 2, thus preventing the annular float 3 from being stuck by oil and ensuring that the annular float 3 can move. The stability of the magnetic field; the vibration generated by the transformer operation and the oil replenishment operation of the oil tank will cause the transformer oil inside the oil tank to flow, thereby causing the radial centering block 4 to vibrate due to the elastic connection, thus cleaning the oil stains on the measuring rod 2. After cleaning, the radial centering block 4 returns to the horizontal state under the action of the spring force 5. In order to ensure the stability of the magnetic field when the annular float 3 is operating, the radial centering block 4 is locked by the dynamic locking part 6. In order to ensure that the annular float 3 can make the radial centering block 4 swing against the elastic force of the spring 5, the elastic force range of the spring 5 is set to 1N-1.The 5N arc surface 16 improves the fit between the radial centering block 4 and the measuring rod 2, ensuring a constant gap between them. The chamfer 17, when the radial centering block 4 rotates to chamfer 17, causes its horizontal length from the rotating support shaft 8 to decrease. This allows the rotating support shaft 8 to rotate over the oil stains without horizontal movement, reducing the deformation of the spring 5. This allows the radial centering block 4 to move over the oil stains with a smaller swing angle, resulting in a smaller difference between buoyancy and gravity. This means that the height difference between when the annular float 3 is stuck and when it is not stuck is small, thus effectively improving the accuracy of the oil level gauge measurement. The conical surface reduces the resistance of the oil film when the radial centering block 4 moves away from the center of the annular float 3, preventing the radial centering block 4 from getting stuck. It also allows the scraped oil film to be conveyed along the conical surface to the chip removal gap 14, further preventing the radial centering block 4 from getting stuck. The inclined surface 15 reduces the contact area between the radial centering block 4 and the sidewall of the groove 7, reducing the moving resistance of the radial centering block 4.

[0027] Please see Figures 1 to 6 as well as Figure 9The dynamic locking component 6 includes a release block 61, a limiting base plate 62, and a locking mating surface 63. The release block 61 is located inside the annular float 3 and includes a buoyancy part 611 and a positioning part 612. The two ends of the limiting base plate 62 are connected to the buoyancy part 611 and the positioning part 612, respectively. A stop plate 64 is provided on the limiting base plate 62, and the stop plate 64 cooperates with the locking mating surface 63. The buoyancy part 611 is located below, and the positioning part 612 is located above, with the positioning part 612 above the oil surface. When the annular float 3 is not stuck, the buoyancy part 611 is subjected to buoyancy, pushing the stop plate 64 to a horizontal position with the locking mating surface 63. When 63 is a plane, the radial centering block 4 is restricted from moving away from the center of the annular float 3. Because the oil level change is small due to vibration, the radial centering block 4 cannot produce a large angle of oscillation and cannot overcome the thrust of the spring 5 to produce a large amplitude of oscillation. At this time, the stop plate 64 keeps the radial centering block 4 stable, thus preventing it from moving axially a large distance due to liquid level fluctuations, which would cause the annular float 3 to shake violently and affect the stability of the magnetic field of the annular float 3. This ensures the accuracy of the oil level gauge measurement. When the liquid level drops and the annular float 3 is stuck, the release block 61 moves downward under gravity, thereby driving the limiting base... Plate 62 moves downward, causing stop plate 64 to move below locking mating surface 63. At this time, the radial centering block 4 is released from locking. When the liquid level rises and the annular float 3 is stuck, release block 61 moves upward under the action of buoyancy, causing stop plate 64 to move above unlocking surface. At this time, the radial centering block 4 is released from locking again. This ensures that the radial centering block 4 cannot move in an angular amplitude during normal operation of the oil level gauge, thus preventing the annular float 3 from swinging too much. When the annular float 3 of the oil level gauge is stuck, the locking of the radial centering block 4 can be released, allowing the radial centering block 4 to overcome the elastic force of spring 5 and increase the gap between the radial centering block 4 and the annular float 3. To prevent the annular float 3 from moving and getting stuck due to oil stains, thus ensuring the accuracy of the oil level gauge measurement; the annular float 3 is provided with a guide surface 11, the positioning part 612 is attached to the guide surface 11, the guide surface 11 is inclined, the stop plate 64 is inclined in the opposite direction to the guide surface 11, the annular float 3 is provided with guide surfaces 12 on both the upper and lower sides of the guide surface 11, the lower guide surface 12 is inclined upwards in the direction of the guide surface 11, and the upper guide surface 12 is inclined in the opposite direction to the lower guide surface 12. The upper and lower sides of the positioning part 612 are respectively engaged with the two guide surfaces 12, and the center of gravity of the positioning part 612 and the buoyancy part 611 is biased towards the side of the inclination direction of the guide surface 11;The guide surface 11 is inclined. When the positioning part 612 moves along the guide surface 11, the distance between the stop plate 64 and the locking mating surface 63 gradually decreases, ensuring that the stop plate 64 can move to a position horizontal with the locking mating surface 63. The stop plate 64 is inclined in the opposite direction to the guide surface 11, so that the radial centering block 4 can squeeze the limiting plate 62 when it moves or rotates, causing the limiting plate 62 to move along the guide surface 11. This reduces the width between the guide surface 11 and the locking mating surface 63, thereby pushing the stop plate 64 towards the guide surface 11 during the movement of the radial centering block 4. The inclined surface 11 moves, thereby reducing the clearance between the stop plate 64 and the locking mating surface 63. This prevents the clearance from being too large, which could cause the radial centering block 4 to move significantly, thus reducing the swaying of the annular float 3 and ensuring the stability of the liquid level detection, thereby preventing false alarms. The guide surface 12 allows the positioning part 612 to move along it when the stop plate 64 moves upward or downward. At this time, the clearance between the stop plate 64 and the locking mating surface 63 is at its maximum, thus ensuring the stability of the liquid level detection. When moving upwards, it can move to the horizontal plane of the locking mating surface 63. When the buoyancy part 611 rises under the action of buoyancy, since the center of gravity of the positioning part 612 is located on the side of the inclined direction of the guide surface 11, the positioning part 612 drives the limiting plate 62 to gradually move in the inclined direction of the guide surface 11, thereby reducing the mating gap between the stop plate 64 and the locking mating surface 63 and preventing the radial centering block 4 from swaying too much. There is a compensation gap 9 between the buoyancy part 611 and the annular float 3. The positioning part 612 is slidably connected to the annular float 3, and the limiting plate 62 is movably connected. The buoyancy part 611 has a movable clearance 10 at the connection between the limiting plate 62 and the buoyancy part 611, and a compensation clearance 9 between the buoyancy part 611 and the annular float 3. This prevents the buoyancy part 611 from jamming due to oil buildup. The positioning part 612, being located above, cannot be submerged by transformer oil, thus preventing interference from oil buildup and avoiding jamming of the release block 61 due to oil buildup. This ensures the feasibility of the dynamic locking member 6. The movable clearance 10 prevents the positioning plate from frequently shaking when the buoyancy part 611 is subjected to fluid agitation.

[0028] Working principle: Please refer to Figures 1 to 9 In normal operation, the stop plate 64 and the locking mating surface 63 are in the same vertical plane. At this time, the stop plate 64 restricts the rotation and axial movement of the radial centering block 4. The radial centering block 4 will not be violently shaken by fluid fluctuations. When the annular float 3 moves downward and gets stuck in the oil, the weight of the annular float 3 is greater than the buoyancy it receives. However, the buoyancy part 611 will descend, thereby causing the stop plate 64 to move downward, thus releasing the locking of the radial centering block 4. This allows the radial centering block 4 to overcome the spring force of the spring 5 and rotate or move axially, thereby increasing the gap between the radial centering block 4 and the measuring rod 2, allowing the radial centering block 4 to move over the oil. When the buoyancy part 611 descends, the positioning part 612 descends simultaneously. At this time, the positioning part 612 is guided by the guide surface 12 on the lower side, causing the stop plate 64 to move to the side with the largest distance from the locking mating surface 63. After the annular float 3 falls over the oil, the buoyancy part 611 is pushed by the buoyancy to move the stop plate 64 upward inside the annular float 3 and move to a horizontal position with the locking mating surface 63. When the annular float 3 moves upward and gets stuck by the oil, the weight of the annular float 3 is less than the buoyancy it receives. However, the buoyancy part 611 moves upward, thereby driving the stop plate 64 to move upward, thus releasing the locking of the radial centering block 4. This allows the radial centering block 4 to overcome the spring force of the spring 5 and rotate or move axially, allowing the radial centering block 4 to move over the oil. When the buoyancy part 611 rises, the positioning part 612 rises synchronously. At this time, the positioning part 612 is guided by the upper guide surface 12, causing the stop plate 64 to move to the side with the largest distance from the locking mating surface 63. After the annular float 3 moves upward over the oil, the locking mating surface 63 moves to a position horizontal with the stop plate 64.

[0029] The specific embodiment of the present invention has been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the embodiments described above. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and ideas of the present invention should still fall within the protection scope of the present invention.

Claims

1. A novel power transformer oil level gauge characterized in that, The instrument includes an instrument body (1), a measuring rod (2), and an annular float (3). The measuring rod (2) is mounted on the instrument body (1), and the annular float (3) is fitted on the measuring rod (2). At least three radial centering blocks (4) are evenly arranged in a ring on the annular float (3). A spring (5) connects the radial centering blocks (4) to the annular float (3), and the radial centering blocks (4) are slidably mounted on the annular float (3) in the horizontal direction. The annular float (3) is provided with a dynamic locking component (6). The dynamic locking component (6) has a release block (61). The dynamic locking component (6) is used to lock the radial centering blocks (4) and release the locking of the radial centering blocks (4) when the buoyancy force on the annular float (3) is greater than the gravity or the buoyancy force is less than the gravity.

2. A novel power transformer oil level gauge as claimed in claim 1, wherein, The annular float (3) has a groove (7) and the radial centering block (4) has a rotating support shaft (8). The rotating support shaft (8) is located inside the groove (7). The upper and lower sides of the radial centering block (4) are connected to springs (5), and the springs (5) are arranged in the vertical direction.

3. A novel power transformer oil level gauge as claimed in claim 2, wherein, The dynamic locking component (6) includes a limiting base plate (62) and a locking mating surface (63). The radial centering block (4) has a locking mating surface (63) on the side away from the center of the annular float (3). The release block (61) is slidably mounted on the annular float (3). The release block (61) has a limiting base plate (62) on it. The limiting base plate (62) has a stop plate (64) on it. The stop plate (64) is engaged with the locking mating surface (63).

4. A novel power transformer oil level gauge as claimed in claim 3, wherein, The release block (61) includes a buoyancy part (611) and a positioning part (612). The two ends of the limiting plate (62) are respectively connected to the buoyancy part (611) and the positioning part (612). The positioning part (612) is located above the buoyancy part (611). There is a compensation gap (9) between the buoyancy part (611) and the annular float (3). The positioning part (612) is slidably connected to the annular float (3). The limiting plate (62) is movably connected to the buoyancy part (611), and there is a movable allowance gap (10) at the connection between the limiting plate (62) and the buoyancy part (611).

5. A novel power transformer oil level gauge as claimed in claim 4, wherein, The annular float (3) is provided with a guide surface (11), the positioning part (612) is in contact with the guide surface (11), the guide surface (11) is inclined, and the stop plate (64) is inclined in the opposite direction to the guide surface (11).

6. A novel oil level gauge for power transformers according to claim 5, characterized in that, The annular float (3) is provided with a guide surface (12) on the lower side of the guide surface (11). The guide surface (12) is inclined upward in the direction of inclination of the guide surface (11). The lower side of the positioning part (612) cooperates with the guide surface (12). The center of gravity of the positioning part (612) and the buoyancy part (611) is biased towards the side of the inclination direction of the guide surface (11).

7. A novel oil level gauge for power transformers according to claim 2, characterized in that, The rotating support shaft (8) has a conical block (13) on the side away from the center of the annular float (3). The conical block (13) has a conical surface. The conical surface is inclined towards the radial centering block (4) along the end of the rotating support shaft (8), and the diameter of the conical surface gradually decreases. A chip removal gap (14) is provided between the radial centering block (4) and the annular float (3). The rotating support shaft (8) has a chamfered surface (15) on the side of the slide groove (7).

8. A novel oil level gauge for power transformers according to claim 2, characterized in that, The radial centering block (4) has an arc surface (16) that cooperates with the measuring rod (2) on the side near the center of the annular float (3), and the arc surface (16) has chamfers (17) on both the upper and lower sides.

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