A base tray for online replacement of cooling fans in dry-type transformers

Abstract

This invention provides a base tray for online replacement of cooling fans in dry-type transformers. Under power, a motor system drives an electric push rod to move a fan mounting platform located under the dry-type transformer, sliding it along guide rails. A push-out limit switch and a pull-in limit switch are fixedly connected to both ends of one of the guide rails. The power supply, motor system, push-out limit switch, and pull-in limit switch together constitute a control circuit. The movement position of the fan mounting platform is controlled by controlling whether it touches the push-out or pull-in limit switch during movement. This invention solves the problems of cumbersome operation, poor equipment stability, and high risk associated with traditional transformer fan trays that rely on manual pushing and pulling. The tray provided by this invention features a high degree of automation, precise displacement control, and good safety, reliably ensuring the safety of operators and equipment while improving efficiency.

Description

Technical Field

[0001] This utility model relates to the field of power equipment technology, specifically to a base tray for online replacement of cooling fans in dry-type transformers. Background Technology

[0002] In the field of power equipment technology, the base tray of a dry-type transformer cooling fan is a key device for ensuring the heat dissipation effect and safe and stable operation of the dry-type transformer, and is crucial for ensuring the performance and lifespan of the dry-type transformer during long-term operation. However, traditional base trays for dry-type transformer cooling fans have some shortcomings in use. Specifically: First, traditional base trays for dry-type transformer cooling fans are mostly operated manually by pushing and pulling, which is cumbersome, increases labor costs, and leads to long replacement times and low work efficiency. Second, because the base trays for traditional dry-type transformer cooling fans are manually pushed and pulled, the fan fixing platform may deviate in position during the pushing or pulling process, failing to stop accurately at the predetermined position, thus affecting the normal operation and stability of the equipment. Finally, traditional base trays for dry-type transformer cooling fans lack effective interlocking contacts and other safety protection devices. During the pushing or pulling process of the cooling fan base tray, the motor system may be simultaneously activated in both forward and reverse directions, leading to phase-to-phase short circuits and threatening the safety of equipment and personnel. Based on this, this utility model provides a base tray for dry-type transformer cooling fans that can be replaced online. Utility Model Content

[0003] The purpose of this utility model is to address the technical problems existing in the background art by providing a base tray for online replacement of the cooling fan of a dry transformer.

[0004] To achieve the above objectives, this utility model employs the following technical solution: A base tray for online replaceable cooling fans of dry-type transformers includes a fan mounting platform and pulleys connected to its four corners. The four pulleys are symmetrically arranged in pairs and fall onto two guide rails fixed to the ground outside the dry-type transformer. An electric push rod is connected to one side of the fan mounting platform. Under the action of a power source, the motor system can drive the electric push rod to move the fan mounting platform located under the dry-type transformer and slide it on the guide rails. A push-out limit switch and a pull-in limit switch are fixedly connected to the two ends of one of the guide rails, respectively. The power source, the motor system, the push-out limit switch, and the pull-in limit switch together constitute a control circuit. The movement position of the fan mounting platform is controlled by controlling the fan mounting platform to touch the push-out limit switch or the pull-in limit switch during movement.

[0005] Preferably, the control circuit further includes an emergency stop switch one, a start switch two, a start switch three, a contactor self-locking contact one, a coil engaging one, a contactor self-locking contact two, and a coil engaging two. The power supply and motor system and the emergency stop switch one are connected to the main circuit. The start switch two, the contactor self-locking contact one, the coil engaging one, and the push-out limit switch are connected to branch circuit one. The start switch three, the contactor self-locking contact two, the coil engaging two, and the pull-in limit switch are connected to branch circuit two. Branch circuit one and branch circuit two are connected in parallel.

[0006] Preferably, contactor interlock contact 1 and contactor interlock contact 2, which are normally closed contacts, are connected to branch circuit 1 and branch circuit 2 respectively. When branch circuit 1 is unobstructed and the motor system rotates in the forward direction, contactor interlock contact 2 opens to ensure that branch circuit 2 is disconnected. When branch circuit 2 is unobstructed and the motor system rotates in the reverse direction, contactor interlock contact 1 opens to ensure that branch circuit 1 is disconnected.

[0007] Preferably, a fuse and a thermal overload protection device are connected in series on the main circuit. The fuse melts when a short circuit or overcurrent occurs in the circuit to protect the safety of the entire circuit. The thermal overload protection device automatically cuts off the motor system circuit when the motor system experiences excessive current due to overload or fault, preventing damage to the motor system.

[0008] Preferably, the guide rail adopts a thick-walled steel rail structure with a hardened surface to enhance load-bearing capacity and resistance to deformation, ensuring the stability of the fan mounting platform during movement and extending the service life of the guide rail.

[0009] Preferably, the surface of the fan mounting platform is provided with several rows of equally spaced wavy raised anti-slip textures and several rows of equally spaced circular hollow heat dissipation holes. The anti-slip textures can prevent the cooling fan from sliding on the fan mounting platform, and the heat dissipation holes help dissipate heat and improve the heat dissipation efficiency of the dry-type transformer.

[0010] Preferably, the two guide rails are equipped with buffer devices near the push-out limit switch and the pull-in limit switch to provide buffer when the fan fixing platform is pushed out or pulled in, reduce collision impact, and extend the service life of the equipment.

[0011] Compared with the prior art, this utility model has the following advantages: 1. High degree of automation: No manual operation is required. The movement of the cooling fan fixing platform is driven by an electric push rod controlled by the circuit, realizing the automatic extension and retraction of the cooling fan fixing platform. The operation is convenient and greatly improves work efficiency.

[0012] 2. Precise displacement control: It can accurately control the movement position of the fan fixing platform, ensuring that it can accurately stop at the predetermined position when it is pushed out or pulled in, thereby ensuring the stability and reliability of the equipment operation.

[0013] 3. Significantly improved safety: The interlocking contact design in the control circuit ensures that the motor system can only run in one direction, avoiding simultaneous forward and reverse rotation, effectively preventing short circuits and ensuring the safety of equipment and operators. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a front view of the base tray of the dry-type transformer cooling fan of this utility model.

[0016] Figure 2 This is the control circuit diagram of the basic tray of the dry-type transformer cooling fan of this utility model.

[0017] 1. Fan mounting platform; 2. Power supply unit; 3. Motor system; 4. Pulley; 5. Guide rail; 6. Electric push rod; 7. Push-out limit switch; 8. Pull-in limit switch; 9. Emergency stop switch one; 10. Start switch two; 11. Start switch three; 12. Contactor self-locking contact one; 13. Engaging coil one; 14. Contactor interlock contact one; 15. Contactor self-locking contact two; 16. Engaging coil two; 17. Contactor interlock contact two; 18. Fuse; 19. Thermal overload protection device; 20. Anti-slip texture; 21. Heat dissipation holes; 22. Buffer device. Detailed Implementation

[0018] The following is in conjunction with the appendix Figure 1-2 The embodiments of this utility model will be described in further detail below.

[0019] like Figure 1 As shown, an electric push rod 6 is connected to one side of the fan mounting platform 1. Each of the four corners of the fan mounting platform 1 is connected to a pulley 4. The four pulleys 4 are symmetrical in pairs and fall into two guide rails 5 fixed on the ground outside the dry-type transformer. The guide rails 5 are made of thick-walled steel rails with hardened surfaces to enhance load-bearing capacity and resistance to deformation, ensuring the stability of the fan mounting platform 1 during movement and extending the service life of the guide rails 5. The surface of the fan mounting platform 1 is provided with several rows of equidistant wavy raised anti-slip textures 20 and several rows of equidistant circular hollow heat dissipation holes 21. The anti-slip textures 20 can prevent the cooling fan from sliding on the fan mounting platform 1, and the heat dissipation holes 21 help dissipate heat and improve the heat dissipation efficiency of the dry-type transformer.

[0020] One guide rail 5 has a push-out limit switch 7 and a pull-in limit switch 8 fixedly connected to its two ends. The electric push rod 6 connected to the fan mounting platform 1 is electrically connected to the push-out limit switch 7 and the pull-in limit switch 8. The electric push rod 6 can be driven to move the fan mounting platform 1 located under the dry-type transformer. During the movement of the fan mounting platform 1, it will touch the push-out limit switch 7 or the pull-in limit switch 8, causing them to disconnect and thus controlling the movement position of the fan mounting platform 1. Both guide rails 5 are equipped with buffer devices 22 near the push-out limit switch 7 and the pull-in limit switch 8 to provide cushioning when the fan mounting platform 1 is pushed out or pulled in, reducing impact and extending the service life of the equipment.

[0021] like Figure 2 As shown, power supply 2, motor system 3, emergency stop switch 19, fuse 18, and thermal overload protection device 19 are all connected to the main circuit. The push-out limit switch 7, start switch 2 10, contactor self-locking contact 12, coil 13, and interlock contact 14 are connected to branch circuit 1. The pull-in limit switch 8, start switch 3 11, contactor self-locking contact 2 15, coil 2 16, and interlock contact 2 17 are connected to branch circuit 2. Branch circuit 1 and branch circuit 2 are connected in parallel.

[0022] The specific working principle is as follows: When the cooling fan on the fan mounting platform 1 is damaged and needs to be replaced, the fan mounting platform 1 needs to be pushed out to find more space to replace the cooling fan. First, close the emergency stop switch 9 on the main line and the start switch 10 on the branch line. The current in the power supply 2 begins to flow through the coil 13. Due to the electromagnetic effect, the coil 13 generates a magnetic field, causing the contactor self-locking contact 12 to close. The normally closed contact interlocking contact 14 closes, and the normally closed contact interlocking contact 17 opens, pushing out the limit switch 7. When closed, the motor system 3 rotates in the forward direction, driving the electric push rod 6 to push the fan mounting platform 1 to slide on the guide rail 5 by relying on the pulleys 4 at the four corners. When the fan mounting platform 1 moves to one of the pulleys 4 and touches the push-out limit switch 7, the push-out limit switch 7 is opened, there is no current in the circuit, the magnetic field generated by the coil 13 disappears, causing the contactor self-locking contact 12 to open, the motor system 3 stops driving the electric push rod 6 to continue pushing the fan mounting platform 1 to slide on the guide rail 5, and the staff can start to replace the broken cooling fan on the fan mounting platform 1.

[0023] When the damaged cooling fan on the fan mounting platform 1 has been replaced, the fan mounting platform 1 needs to be pulled back under the dry-type transformer. First, close the start switch 11. Current flows through the pull-in coil 16. Due to electromagnetic induction, the magnetic field generated by the pull-in coil 16 causes the contactor's self-locking contact 15 to close. The normally closed contact of the contactor interlocking contact 14 opens, and the normally closed contact of the contactor interlocking contact 17 closes. The limit switch 8 closes, and the motor system 3 rotates in the reverse direction, driving the electric push rod 6 to pull the fan mounting platform. The fixed platform 1 slides on the guide rail 5 using the pulleys 4 at its four corners. When the fan fixed platform 1 moves to one of the pulleys 4 and touches the pull-in limit switch 8, the pull-in limit switch 8 is opened, there is no current in the circuit, the magnetic field generated by the second coil 16 disappears, the contactor self-locking contact 15 is opened, the motor system 3 stops driving the electric push rod 6 to continue pulling the fan fixed platform 1 to slide on the guide rail 5. When the fan fixed platform 1 reaches the designated position below the dry transformer, the emergency stop switch 9 is turned off, and the cooling fan replacement process ends.

[0024] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the concept of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A base tray for online replaceable cooling fans of dry-type transformers, comprising a fan fixing platform (1) and pulleys (4) connected at its four corners, wherein the four pulleys (4) are symmetrically arranged in pairs and respectively fall into two guide rails (5) fixed on the ground outside the dry-type transformer, characterized in that: An electric push rod (6) is connected to one side of the fan fixing platform (1). Under the action of the power supply (2), the motor system (3) can drive the electric push rod (6) to move the fan fixing platform (1) located under the dry transformer to slide on the guide rail (5). At the two ends of one of the guide rails (5), a push-out limit switch (7) and a pull-in limit switch (8) are fixedly connected respectively. The power supply (2), the motor system (3), the push-out limit switch (7), and the pull-in limit switch (8) together constitute a control circuit. By controlling the fan fixing platform (1) to touch the push-out limit switch (7) or the pull-in limit switch (8) during the movement, the movement position of the fan fixing platform (1) is controlled.

2. The base tray for an online replaceable dry-type transformer cooling fan according to claim 1, characterized in that: The control circuit also includes an emergency stop switch (9), a start switch (10), a start switch (11), a contactor self-locking contact (12), a coil (13), a contactor self-locking contact (15), and a coil (16). The power supply (2) is connected to the motor system (3) and the emergency stop switch (9) on the main circuit. The start switch (10) is connected to the contactor self-locking contact (12), the coil (13), and the push-out limit switch (7) on the branch circuit. The start switch (11) is connected to the contactor self-locking contact (15), the coil (16), and the pull-in limit switch (8) on the branch circuit. The branch circuit and the branch circuit are connected in parallel.

3. The base tray for an online replaceable dry-type transformer cooling fan according to claim 2, characterized in that: Contactor interlock contact 1 (14) and contactor interlock contact 2 (17), which are normally closed contacts, are connected to branch 1 and branch 2 respectively. When branch 1 is unobstructed and the motor system (3) rotates in the forward direction, contactor interlock contact 2 (17) is opened to ensure that branch 2 is open. When branch 2 is unobstructed and the motor system (3) rotates in the reverse direction, contactor interlock contact 1 (14) is opened to ensure that branch 1 is open.

4. The base tray for an online replaceable dry-type transformer cooling fan according to claim 2, characterized in that: A fuse (18) and a thermal overload protection device (19) are connected in series on the main line. The fuse (18) melts when a short circuit or overcurrent occurs in the circuit to protect the safety of the entire circuit. The thermal overload protection device (19) automatically cuts off the circuit of the motor system (3) when the current is too high due to overload or fault, to prevent damage to the motor system (3).

5. The base tray for an online replaceable dry-type transformer cooling fan according to claim 1, characterized in that: The guide rail (5) adopts a thick-walled steel rail structure and the surface is hardened to enhance the load-bearing capacity and deformation resistance, ensure the stability of the fan fixing platform (1) during movement, and extend the service life of the guide rail (5).

6. The base tray for an online replaceable dry-type transformer cooling fan according to claim 1, characterized in that: The surface of the fan mounting platform (1) is provided with several rows of equally spaced wave-shaped raised anti-slip textures (20) and several rows of equally spaced circular hollow heat dissipation holes (21). The anti-slip textures (20) can prevent the cooling fan from sliding on the fan mounting platform (1), and the heat dissipation holes (21) help dissipate heat and improve the heat dissipation efficiency of the dry-type transformer.

7. The base tray for an online replaceable dry-type transformer cooling fan according to claim 1, characterized in that: Two guide rails (5) are equipped with buffer devices (22) near the push-out limit switch (7) and pull-in limit switch (8) to provide buffer when the fan fixing platform (1) is pushed out or pulled in, reduce collision impact and extend the service life of the equipment.

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