A transformer breather

Abstract

The present invention provides a transformer breather, belonging to the technical field of transformers. This transformer breather includes a mounting base, a silica gel cover, a valve seat, and desiccant filled in the silica gel cover. The valve seat and the mounting base are respectively connected to both ends of the silica gel cover. The mounting base is provided with a connecting pipe connecting to the inner cavity of the transformer oil shell. The valve seat is provided with a valve hole, and the valve hole connects to the inner cavity of the silica gel cover. The valve seat is provided with a plurality of breathing holes communicating the valve hole with the outside. A two-way pressure limiting valve is arranged in the valve hole. The present invention has the advantages of being able to extend the service life of the breather, etc.

Description

Technical Field

[0001] The present invention belongs to the technical field of transformers and relates to a transformer breather. Background Art

[0002] A transformer breather is an essential component of an oil-immersed transformer device. Its main function is to filter and absorb moisture and impurities in the air entering the transformer interior, thereby ensuring the quality of the transformer oil. Since the silica gel desiccant used for filtering moisture and impurities gets damp during use due to continuously absorbing the moisture inhaled into the transformer oil tank, it is necessary to regularly replace the breather or the desiccant, which increases the maintenance cost and is prone to safety hazards.

[0003] In fact, the moisture that makes the silica gel desiccant in the breather damp does not only come from the air inhaled into the transformer oil tank. Since the breathing port connecting the breather to the outside world is in an open state all the time, the outside air and the interior of the breather conduct relatively slow convection, causing a large amount of "useless moisture" to enter the silica gel desiccant in the breather when the breather is not "breathing". Assuming there is no influence of this part of moisture on the silica gel desiccant, the replacement cycle of the breather can be greatly extended.

[0004] When the breather needs to "breathe", it is when the internal pressure of the transformer oil tank changes due to factors such as temperature, causing the transformer oil to expand or contract. As is well known, the change of the external environment is relatively slow. Even the heat generated by the operation of the transformer winding will make the temperature in the transformer oil tank in a state where there are multiple gentle periods and multiple sudden change points due to the heat dissipation system. In fact, when the temperature fluctuation range in the transformer oil tank is small, the function of the breather is very small, the air pressure difference between the inside and outside of the oil tank is small, and it has no impact on the normal operation and safety of the transformer. Only when the pressure difference inside the oil tank is large, the breather can have a substantial impact on the safety and normal operation of the transformer. Based on this, if the opening and closing of the breather are determined by the magnitude of the pressure difference between the inside and outside of the oil tank, not only can the "breathing frequency" of the breather be greatly reduced, but also the long-term contact between the outside air and the desiccant in the breather can be effectively avoided, eliminating the entry of "useless moisture" into the desiccant, thereby extending the service life and maintenance cycle of the breather. Summary of the Invention

[0005] The object of the present invention is to provide a transformer breather in view of the above problems existing in the prior art. The technical problem to be solved by the present invention is how to prevent the desiccant from getting damp when the breather is not working.

[0006] The object of the present invention can be achieved by the following technical solutions: A transformer breather, characterized in that the transformer breather includes a mounting seat, a silica gel cover, a valve seat, and desiccant filled in the silica gel cover. The valve seat and the mounting seat are respectively connected to both ends of the silica gel cover. The mounting seat is provided with a connecting pipe connecting to the inner cavity of the transformer oil shell. The valve seat is provided with a valve hole, and the valve hole is connected to the inner cavity of the silica gel cover. The valve seat is provided with a plurality of breathing holes communicating the valve hole with the outside, and a two-way pressure limiting valve is arranged in the valve hole.

[0007] In the above-mentioned transformer breather, the two-way pressure limiting valve includes a mounting sleeve fixed on the inner wall of the valve hole, a valve rod slidably connected to the valve seat, and a sealing disc arranged on the valve rod. The sealing disc includes a body, a first rubber sleeve, and a plurality of permanent magnet bars. The body is provided with sliding holes corresponding to each permanent magnet bar one by one. The sliding holes are circumferentially and uniformly distributed on the body. Each permanent magnet bar is slidably connected to the corresponding sliding hole along the radial line of the body. The first rubber sleeve is wrapped outside the body, and the body is fixed on the valve rod. The mounting sleeve is made of iron material, and a second rubber sleeve wrapping the mounting sleeve is fixedly arranged on the mounting sleeve. A return spring for driving the sealing disc to be located in the mounting sleeve is sleeved on the valve rod.

[0008] In the above-mentioned transformer breather, a closed hydraulic cavity is arranged in the valve seat. A valve block slidably connected to the hydraulic cavity along the axial direction of the valve rod is fixedly arranged on the valve rod. The valve block divides the hydraulic cavity into a first liquid storage cavity and a second liquid storage cavity. The valve block is provided with a plurality of through-flow holes. A baffle located on the side of the valve block close to the silica gel cover is slidably connected to the valve rod. The baffle can block each through-flow hole. There are two return springs, and both return springs are in a compressed state. One end of one return spring respectively abuts between the baffle and the bottom wall surface of the hydraulic cavity, and the two ends of the other return spring respectively abut between the valve block and the top wall surface of the liquid storage cavity. An overflow hole is arranged on the baffle, and the overflow hole is opposite to one of the through-flow holes. The overflow hole can communicate the first liquid storage cavity and the second liquid storage cavity. A liquid exchange hole for communicating the first liquid storage cavity and the second liquid storage cavity is arranged on the valve rod. An insertion rod fixedly arranged in the hydraulic cavity can be inserted into the liquid exchange hole and block the liquid exchange hole during the upward movement of the valve rod. The hydraulic cavity is filled with hydraulic oil.

[0009] In the above-mentioned transformer breather, an annular heating strip is arranged on the side surface of the mounting seat facing the inner cavity of the silica gel cover. A position switch that can be triggered by the insertion rod is arranged on the inner wall of the liquid exchange hole. When the position switch is triggered, the heating strip is powered on.

[0010] In the above-mentioned transformer breather, a dust-proof cover wrapping outside each breathing hole is arranged on the valve seat.

[0011] The dust cover can detour the gas flow path entering the breathing hole, and make the inlet face downward to prevent dust and large impurities from entering.

[0012] In the above-mentioned transformer breather, a number of connection holes are provided on the valve seat.

[0013] The connection holes are used for bolt connection between the valve seat and the transformer housing.

[0014] In the above-mentioned transformer breather, chamfers are provided on both the upper and lower sides of the inner edge of the mounting sleeve.

[0015] When the pressure difference between the inside and outside of the oil shell of the oil-immersed transformer is small, under the action of the adsorption force between the permanent magnet strip and the iron mounting sleeve, the valve hole is blocked, and the breathing hole cannot communicate with the inner cavity of the silica gel cover. The breather is in the "active sleep state" to prevent the moisture in the outside air from being absorbed by the desiccant;

[0016] When the pressure inside the oil shell of the oil-immersed transformer is greater than the outside pressure and a large pressure difference is formed, the pressure inside the oil shell overcomes the adsorption force between the permanent magnet strip and the iron mounting sleeve, causing the sealing disc to move upward. And due to the sudden decrease in the adsorption force between the permanent magnet strip and the iron mounting sleeve, the sealing disc instantaneously moves upward a large distance together with the valve rod under the action of the large pressure. The liquid storage cavity I above the valve block and the liquid storage cavity II below the valve block quickly reach oil pressure balance. During this process, the restoring force of the return spring below the valve block gradually decreases, and the restoring force of the return spring below the valve block gradually increases. The valve block moves downward under the action of the return spring with a larger restoring force. At this time, the only channel connecting the liquid storage cavity I and the liquid storage cavity II is the overflow hole with a smaller flow cross-section, and the difference in the restoring forces of the two return springs gradually decreases, making the downward movement speed of the valve block slower and the time for the sealing disc to be in the open state longer. During this process, the insertion rod is inserted into the liquid change cavity and triggers the position switch, making the heating strip energized to heat the inside of the silica gel cover, forming hot air to be discharged. Under the action of the outward air flow during the "exhalation" process of the breather, the hot air discharge efficiency is improved; when the sealing disc approaches the mounting sleeve, under the action of the adsorption force between the permanent magnet strip and the iron mounting sleeve, the sealing disc quickly returns to the central position that can maintain the maximum adsorption force with the mounting sleeve, and the permanent magnet strip moves outward under the radial magnetic force, causing the rubber sleeve I and the rubber sleeve II to approach and press against each other to achieve good sealing to prevent pressure relief due to poor sealing;

[0017] When the pressure in the oil shell of the oil-immersed transformer is lower than the external pressure and a large pressure difference is formed, the sealing disc moves downward due to the negative pressure in the oil shell, overcoming the magnetic force to open the valve hole, and the external air enters the silicone cover through the breathing hole, and enters the oil shell after being dried and filtered. During the downward movement of the valve stem and the sealing disc, the plug rod is separated from the blockage of the liquid exchange hole, and the liquid exchange hole forms a channel for the liquid storage chamber 1 and the liquid storage chamber 2 to communicate with each other. After the pressure inside and outside the oil shell is balanced, the sealing disc is quickly reset by the reset spring until the sealing disc is in the installation sleeve. At this time, the plug rod is inserted into the liquid exchange hole to block the liquid exchange hole.

[0018] The position switch is a normally open switch, which is connected in series in the loop formed by the power supply and the heating strip. It is triggered only when the rod is inserted and returns to the normally open state when the rod is removed. This circuit is a simple conventional circuit.

[0019] The upper and lower sides of the mounting sleeve are chamfered. When wrapped by the rubber sleeve 1, the permanent magnetic strip is in a state away from the mounting sleeve before it is affected by the magnetic force of the mounting sleeve, that is, it moves to a position close to the valve stem axis in the sliding hole. Before the sealing disk approaches the mounting sleeve, the chamfer setting makes the permanent magnetic strip receive less external pulling force until the sealing disk enters the mounting sleeve. When the distance between the inner wall of the mounting sleeve and the permanent magnetic strip decreases, the adsorption force is greater, so the sealing disk can smoothly enter the mounting sleeve. The main body is made of non-magnetic material, such as copper-aluminum alloy, and the rubber sleeve 1 and the rubber sleeve 2 are respectively snapped on the main body and the mounting seat.

[0020] Compared with the existing technology, this solution has the following advantages:

[0021] By setting up a two-way pressure-limiting valve, the frequency of the silicone cover communicating with the outside world is reduced, which prevents the respirator from corrosion, aging, and moisture to the desiccant when not in operation, thereby extending the service life and inspection cycle of the respirator.

[0022] The one-way resistance structure composed of the valve block, baffle, return spring, overflow hole, plug rod and liquid exchange hole not only realizes the bidirectional movement of the valve stem to cooperate with the action of the bidirectional pressure-limiting valve, but also, through the cooperation with the bidirectional pressure-limiting valve, when the sealing disk moves up and opens, that is, when the respirator is in the "exhalation" state, the sealing disk quickly separates from the installation sleeve and moves slowly to seal the installation sleeve, leaving more exhaust time for the heating strip to dry the desiccant and discharge the hot air, thereby achieving the purpose of actively drying the desiccant during use and further extending the service life of the respirator.

[0023] The two-way pressure-limiting valve with a magnetic structure not only achieves a better sealing effect, but also can accumulate force before the valve stem moves upward, so that the valve stem moves upward a greater distance, thereby achieving the purpose of extending the "exhalation" time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the transformer respirator.

[0025] Figure 2 It is a schematic structural diagram of a two-way pressure limiting valve when the breathing apparatus is in a non-operating state.

[0026] Figure 3 It is a schematic structural diagram of a two-way pressure limiting valve when the breathing apparatus is in an exhalation state.

[0027] Figure 4 It is a schematic structural diagram of a two-way pressure limiting valve when the breathing apparatus is in an inhalation state.

[0028] Figure 5 It is a cross-sectional view of the sealing disc.

[0029] Figure 6 It is Figure 5 A cross-sectional view taken along the A-A direction in

[0030] In the figure, 1 is the mounting seat; 11 is the silica gel cover; 12 is the connecting pipe; 13 is the breathing hole; 14 is the dust-proof cover; 2 is the valve seat; 21 is the valve stem; 22 is the return spring; 23 is the connecting hole; 24 is the valve hole; 31 is the mounting sleeve; 32 is the second rubber sleeve; 4 is the sealing disc; 41 is the body; 42 is the first rubber sleeve; 43 is the permanent magnet strip; 51 is the valve block; 52 is the first liquid storage cavity; 53 is the second liquid storage cavity; 54 is the through-flow hole; 55 is the baffle; 56 is the overflow hole; 57 is the liquid change hole; 58 is the inserting rod; 61 is the heating strip; 62 is the position switch. Specific embodiments

[0031] The following are specific embodiments of the present invention and in combination with the accompanying drawings, the technical solutions of the present invention are further described, but the present invention is not limited to these embodiments.

[0032] As Figure 1 shown, the transformer breathing apparatus of the present invention includes a mounting seat 1, a silica gel cover 11, a valve seat 2, and a desiccant filled in the silica gel cover 11. The valve seat 2 and the mounting seat 1 are respectively connected to both ends of the silica gel cover 11. The mounting seat 1 is provided with a connecting pipe 12 connecting to the inner cavity of the transformer oil shell. The valve seat 2 is provided with a valve hole 24, and the valve hole 24 is connected to the inner cavity of the silica gel cover 11. The valve seat 2 is provided with a plurality of breathing holes 13 communicating the valve hole 24 with the outside. A two-way pressure limiting valve is arranged in the valve hole 24. The two-way pressure limiting valve can be an ordinary double-spring pressure limiting valve, that is, by respectively arranging a spring at both ends of the valve, opening the valve needs to overcome the restoring force of one of the springs, and the valve is closed by the return of the compressed spring.

[0033] As Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6As shown in the figure, the two-way pressure limiting valve includes a mounting sleeve 31 fixed to the inner wall of the valve hole 24, a valve stem 21 slidably connected to the valve seat 2, and a sealing disc 4 provided on the valve stem 21. The sealing disc 4 includes a body 41, a first rubber sleeve 42, and a number of permanent magnet bars 43. The body 41 has sliding holes corresponding to the permanent magnet bars 43 one by one. The sliding holes are circumferentially and evenly distributed on the body 41. Each permanent magnet bar 43 is slidably connected to the corresponding sliding hole along the radial line of the body 41. The first rubber sleeve 42 is wrapped outside the body 41, and the body 41 is fixed to the valve stem 21. The mounting sleeve 31 is made of iron material, and a second rubber sleeve 32 wrapping the mounting sleeve 31 is fixedly provided on the mounting sleeve 31. A return spring 22 for driving the sealing disc 4 to be located inside the mounting sleeve 31 is sleeved on the valve stem 21.

[0034] There is a sealed hydraulic cavity inside the valve seat 2. A valve block 51 is fixedly provided on the valve stem 21 and is slidably connected to the hydraulic cavity along the axis of the valve stem 21. The valve block 51 divides the hydraulic cavity into a first liquid storage cavity 52 and a second liquid storage cavity 53. A number of flow holes 54 are opened on the valve block 51. A baffle 55 is slidably connected to the valve stem 21 on the side of the valve block 51 close to the silica gel cover 11. The baffle 55 can block each flow hole 54. There are two return springs 22, and both return springs 22 are in a compressed state. One end of one return spring 22 abuts between the baffle 55 and the bottom wall surface of the hydraulic cavity respectively, and the two ends of the other return spring 22 abut between the valve block 51 and the top wall surface of the liquid storage cavity respectively. An overflow hole 56 is opened on the baffle 55, and the overflow hole 56 is aligned with one of the flow holes 54. The overflow hole 56 can communicate the first liquid storage cavity 52 and the second liquid storage cavity 53. A liquid exchange hole 57 for communicating the first liquid storage cavity 52 and the second liquid storage cavity 53 is opened on the valve stem 21. An insertion rod 58 that can be inserted into the liquid exchange hole 57 and block the liquid exchange hole 57 during the upward movement of the valve stem 21 is fixedly provided in the hydraulic cavity. The hydraulic cavity is filled with hydraulic oil.

[0035] On one side of the mounting seat 1 facing the inner cavity of the silica gel cover 11, an annular heating strip 61 is provided. A position switch 62 that can be triggered by the insertion rod 58 is provided on the inner wall of the liquid exchange hole 57. When the position switch 62 is triggered, the heating strip 61 is powered on.

[0036] A dust-proof cover 14 is provided on the valve seat 2 and wraps outside each breathing hole 13. The dust-proof cover 14 can make the gas flow path entering the breathing hole 13 circuitous, and make the inlet face downward, avoiding dust entry and large impurities entry.

[0037] The valve seat 2 has a number of connection holes 23. The connection holes 23 are used for bolt connection between the valve seat 2 and the transformer housing.

[0038] Both the upper and lower sides of the inner edge of the mounting sleeve 31 have chamfers.

[0039] When the pressure difference between the inside and outside of the oil shell of the oil-immersed transformer is small, the valve hole 24 is blocked by the adsorption force between the permanent magnet strip 43 and the iron installation sleeve 31, and the breathing hole 13 cannot communicate with the inner cavity of the silica gel cover 11. The breather is in an "active sleep state" to prevent moisture in the outside air from being absorbed by the desiccant.

[0040] When the pressure inside the oil shell of the oil-immersed transformer is greater than the outside pressure and a large pressure difference is formed, the pressure inside the oil shell overcomes the adsorption force between the permanent magnet strip 43 and the iron installation sleeve 31, causing the sealing disk 4 to move upward. And due to the sudden decrease in the adsorption force between the permanent magnet strip 43 and the iron installation sleeve 31, the sealing disk 4 instantaneously moves upward a large distance together with the valve rod 21 under the action of the large pressure. The liquid storage cavity one 52 above the valve block 51 and the liquid storage cavity two 53 below the valve block 51 quickly reach oil pressure balance. Since the restoring force of the return spring 22 below the valve block 51 gradually decreases and the restoring force of the return spring 22 above the valve block 51 gradually increases during this process, the valve block 51 moves downward under the action of the return spring 22 with a larger restoring force. Since the only channel connecting the liquid storage cavity one 52 and the liquid storage cavity two 53 at this time is the overflow hole 56 with a smaller flow cross-section, and the difference in the restoring forces of the two return springs 22 gradually decreases, the downward movement speed of the valve block 51 is slower, and the time for the sealing disk 4 to be in the open state is longer. During this process, the insertion rod 58 is inserted into the liquid exchange cavity and triggers the position switch 62, causing the heating strip 61 to be energized to heat the inside of the silica gel cover 11 to form hot air for discharge. Due to the outward air flow during the "exhalation" process of the breather, the discharge efficiency of the hot air is improved; when the sealing disk 4 approaches the installation sleeve 31, under the adsorption force between the permanent magnet strip 43 and the iron installation sleeve 31, the sealing disk 4 quickly returns to the central position that can maintain the maximum adsorption force with the installation sleeve 31, and the permanent magnet strip 43 moves outward under the radial magnetic force, causing the rubber sleeve one 42 and the rubber sleeve two 32 to approach and press against each other to achieve good sealing to prevent pressure relief due to poor sealing.

[0041] When the pressure inside the oil shell of the oil-immersed transformer is less than the outside pressure and a large pressure difference is formed, the sealing disk 4 moves downward under the action of the negative pressure inside the oil shell, overcoming the magnetic force to open the valve hole 24. The outside air enters the silica gel cover 11 through the breathing hole 13, and after being dried and filtered, it enters the oil shell. During the downward movement of the valve rod 21 and the sealing disk 4, the insertion rod 58 disengages from the blockage of the liquid exchange hole 57, and the liquid exchange hole 57 forms a channel for the liquid storage cavity one 52 and the liquid storage cavity two 53 to communicate. After the pressure inside and outside the oil shell is balanced, the sealing disk 4 quickly returns to its original position under the action of the return spring 22 until the sealing disk 4 is inside the installation sleeve 31. At this time, the insertion rod 58 is inserted into the liquid exchange hole 57 to block the liquid exchange hole 57.

[0042] The position switch 62 is a normally open switch, connected in series in the circuit formed by the power supply and the heating strip 61, and is triggered only when the insertion rod 58 is inserted, and returns to the normally open state when the insertion rod 58 leaves. This circuit is a simple conventional circuit.

[0043] The mounting sleeve 31 has chamfers on both the upper and lower sides. When wrapped by the rubber sleeve 1 42, the permanent magnet strip 43 is in a state of being away from the mounting sleeve 31 before being affected by the magnetic force of the mounting sleeve 31, that is, it moves to a position close to the axis of the valve stem 21 in the sliding hole. Before the sealing disk 4 approaches the mounting sleeve 31, the chamfer setting makes the external pulling force on the permanent magnet strip 43 smaller until the sealing disk 4 enters the mounting sleeve 31. When the distance between the inner wall of the mounting sleeve 31 and the permanent magnet strip 43 is reduced, the adsorption force is larger, so the sealing disk 4 can smoothly enter the mounting sleeve 31, wherein the main body 41 is made of non-magnetic material, such as copper-aluminum alloy, and the rubber sleeve 1 42 and the rubber sleeve 2 32 are respectively snapped on the main body 41 and the mounting seat 1.

[0044] Compared with the existing technology, this solution has the following advantages:

[0045] By setting the two-way pressure limiting valve, the frequency of the silicone cover 11 communicating with the outside world is reduced, corrosion and aging of the respirator and moisture exposure of the desiccant in a non-working state are avoided, and the service life and replacement cycle of the respirator are extended.

[0046] The one-way resistance structure composed of the valve block 51, the baffle 55, the return spring 22, the overflow hole 56, the plug rod 58 and the liquid exchange hole 57 not only realizes the bidirectional movement of the valve stem 21 to cooperate with the action of the bidirectional pressure-limiting valve, but also, through the cooperation with the bidirectional pressure-limiting valve, when the sealing disk 4 moves up and opens, that is, when the respirator is in the "exhalation" state, the sealing disk 4 quickly separates from the mounting sleeve 31 and moves slowly to seal the mounting sleeve 31, leaving more exhaust time for the heating strip 61 to dry the desiccant and discharge the hot air, thereby achieving the purpose of actively drying the desiccant during use, further extending the use cycle of the respirator.

[0047] The two-way pressure-limiting valve with a magnetic structure not only achieves a better sealing effect, but also can accumulate force before the valve stem 21 moves upward, so that the valve stem 21 moves upward a greater distance, thereby achieving the purpose of extending the "exhalation" time.

[0048] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A transformer breather, characterized in that, this transformer breather includes a mounting seat (1), a silica gel cover (11), a valve seat (2), and a desiccant filled in the silica gel cover (11). The valve seat (2) and the mounting seat (1) are respectively connected to both ends of the silica gel cover (11). The mounting seat (1) has a connecting pipe (12) connecting to the inner cavity of the transformer oil shell. The valve seat (2) has a valve hole (24), and the valve hole (24) connects to the inner cavity of the silica gel cover (11). A number of breathing holes (13) communicating the valve hole (24) with the outside are provided on the valve seat (2), and a two-way pressure limiting valve is arranged in the valve hole (24); the two-way pressure limiting valve includes a mounting sleeve (31) fixed on the inner wall of the valve hole (24), a valve rod (21) slidably connected to the valve seat (2), and a sealing disc (4) arranged on the valve rod (21). The sealing disc (4) includes a body (41), a first rubber sleeve (42), and a number of permanent magnet bars (43). The body (41) has sliding holes corresponding to each permanent magnet bar (43) one by one. The sliding holes are circumferentially and evenly distributed on the body (41). Each permanent magnet bar (43) is slidably connected to the corresponding sliding hole along the radial line of the body (41). The first rubber sleeve (42) is wrapped outside the body (41), and the body (41) is fixed on the valve rod (21); the mounting sleeve (31) is made of iron material, and a second rubber sleeve (32) wrapping the mounting sleeve (31) is fixedly arranged on the mounting sleeve (31). A return spring (22) for driving the sealing disc (4) to be located inside the mounting sleeve (31) is sleeved on the valve rod (21); a dust-proof cover (14) wrapping outside each breathing hole (13) is arranged on the valve seat (2); the valve seat (2) has a number of connecting holes (23).

2. The transformer breather according to claim 1, characterized in that, The valve seat (2) has a sealed hydraulic chamber therein. A valve block (51) is fixedly arranged on the valve stem (21) and is slidably connected in the hydraulic chamber along the axis direction of the valve stem (21). The valve block (51) divides the hydraulic chamber into a first liquid storage chamber (52) and a second liquid storage chamber (53). A plurality of flow holes (54) are formed in the valve block (51). A baffle plate (55) is slidably connected to the valve stem (21) and is located on the side of the valve block (51) close to the silica gel cover (11). The baffle plate (55) can block each flow hole (54). There are two return springs (22), and both of the two return springs (22) are in a compressed state. One end of one return spring (22) abuts between the baffle plate (55) and the bottom wall surface of the hydraulic chamber respectively, and the two ends of the other return spring (22) abut between the valve block (51) and the top wall surface of the liquid storage chamber respectively. An overflow hole (56) is formed in the baffle plate (55), and the overflow hole (56) is opposite to one of the flow holes (54). The overflow hole (56) can communicate the first liquid storage chamber (52) and the second liquid storage chamber (53). A liquid exchange hole (57) that can communicate the first liquid storage chamber (52) and the second liquid storage chamber (53) is formed in the valve stem (21). An insertion rod (58) that can be inserted into the liquid exchange hole (57) and block the liquid exchange hole (57) during the upward movement of the valve stem (21) is fixedly arranged in the hydraulic chamber; the hydraulic chamber is filled with hydraulic oil.

3. The transformer breather according to claim 2, characterized in that a ring-shaped heating strip (61) is arranged on the side surface of the mounting seat (1) facing the inner cavity of the silica gel cover (11); a position switch (62) that can be triggered by the insertion rod (58) is provided on the inner wall of the liquid exchange hole (57); when the position switch (62) is triggered, the heating strip (61) is powered on.

4. The transformer breather according to claim 1 or 2 or 3, characterized in that both the upper and lower sides of the inner edge of the mounting sleeve (31) have chamfers.

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