A transformer without ground wire

Abstract

The application discloses a transformer without ground wire, which comprises a framework and a magnetic core body fixed on the framework, an auxiliary winding, a secondary winding, a shielding layer winding and a primary winding are sequentially wound on the magnetic core body, and an insulating sleeve for providing insulation protection is arranged at a starting wire end of the primary winding to replace a ground wire of the shielding layer winding. The insulating sleeve arranged at the starting wire end of the primary winding can effectively isolate the primary winding from other windings or the magnetic core, and prevent high-voltage breakdown and other conditions from occurring. Meanwhile, the isolation effect of the insulating sleeve can reduce the parasitic capacitance and leakage inductance between the primary winding and other windings, optimize the electromagnetic compatibility of the transformer, and thus realize the function of replacing the ground wire of the shielding layer winding, avoid the short circuit phenomenon between the pins of the transformer caused by the ground wire of the shielding layer winding, and the winding mode is relatively simple, easy to realize automatic production, and improves the production efficiency of the transformer.

Description

Technical Field This utility model relates to the field of transformer technology, and in particular to a transformer without a ground wire. Background Technology With the continuous development of electronic devices, the demand for miniaturized and high-efficiency power conversion equipment is increasing. High-frequency transformers are key components in power conversion equipment, playing a crucial role in improving power conversion efficiency and reducing size.

[0001] To prevent electromagnetic interference (EMI) between transformer windings and between windings and the magnetic core in high-frequency operating environments, existing high-frequency transformers typically suppress EMI by grounding the shielding winding in the winding structure. However, the grounding wire of the shielding winding can easily cause short circuits between transformer pins, increasing safety hazards and failure rates during production. Secondly, the grounding wire complicates the winding structure, hindering automated production and thus reducing production efficiency. Utility Model Content To address the technical problems of structural complexity and susceptibility to short circuits caused by the grounding wire of the shielding winding in current high-frequency transformer winding structures, this utility model provides a transformer without a grounding wire.

[0002] To achieve the above objectives, this utility model is implemented by the following technical solution: A groundless transformer includes a frame and a magnetic core body fixed on the frame. An auxiliary winding, a secondary winding, a shielding layer winding, and a primary winding are wound sequentially on the magnetic core body. The starting end of the primary winding is provided with an insulating sleeve for providing insulation protection, which replaces the grounding wire of the shielding layer winding.

[0003] By adopting the above technical solution, the insulating bushing installed at the starting end of the primary winding can effectively isolate the primary winding from other windings or magnetic cores, preventing high-voltage breakdown and other situations. At the same time, the insulating bushing's isolation function can reduce parasitic capacitance and leakage inductance between the primary winding and other windings, optimize the electromagnetic compatibility of the transformer, and thus replace the grounding wire of the shielding winding. This avoids the short circuit phenomenon between transformer pins that is easily caused by the grounding wire of the shielding winding. Moreover, this winding method is relatively simple, easy to automate, and improves the production efficiency of the transformer.

[0004] As described above, a groundless transformer has a core body comprising a first core and a second core corresponding to the first core, with adhesive dispensing positions provided at the core columns of the first and second cores for fixing to the frame.

[0005] In the above-described groundless transformer, when applying adhesive, the adhesive at the application point should cover 2 / 3 of the area of ​​the magnetic core column, and the adhesive is epoxy resin.

[0006] By adopting the above technical solution and setting the dispensing position, when fixing the first and second magnetic cores to the frame, the first and second magnetic cores can be better fixed by dispensing epoxy resin, stabilizing the magnetic core contact surface between the two magnetic cores and preventing the magnetic cores from misaligning or loosening; at the same time, the dispensing epoxy resin can fill the air gap between the first and second magnetic cores, thereby preventing the magnetic core body from vibrating under the action of the magnetic field and reducing the noise of the transformer.

[0007] As described above, in a groundless transformer, the auxiliary winding starts at the same end of the auxiliary winding and ends at the same end of the shielding layer winding. The auxiliary winding is made by tightly winding a single conductor multiple times.

[0008] By adopting the above technical solution, the auxiliary winding is wound first as the first layer of winding, which can provide a basic insulation layer for the subsequently wound primary and secondary windings, reducing electromagnetic interference between the subsequently wound primary and secondary windings; at the same time, it can also allow the subsequently wound primary and secondary windings to be wound more tightly, increasing the effective coupling area between the windings, thereby reducing leakage inductance and improving the efficiency of the transformer.

[0009] As described above, in a groundless transformer, the secondary winding starts at the same-name end of the secondary winding and ends at the opposite-name end of the secondary winding. The secondary winding is made by tightly winding a single conductor multiple times.

[0010] By adopting the above technical solution, the secondary winding is wound before the primary winding. The purpose is that the copper loss of the secondary winding is more sensitive to the length of the conductor. By winding the secondary winding inside, the winding length can be effectively reduced, thereby reducing copper loss and heat generation. Although the winding length of the outer primary winding is longer, it is located on the outer layer of the transformer and has an insulating sleeve at the starting end, which provides better heat dissipation conditions. This can effectively reduce the temperature rise caused by copper loss and thus improve the heat dissipation capacity of the transformer.

[0011] As described above, in a groundless transformer, the shielding layer winding starts at the same-name end of the shielding layer winding and ends at the opposite-name end of the shielding layer winding. The shielding layer winding is made by tightly winding a single conductor multiple turns.

[0012] By adopting the above technical solution, the shielding layer winding is set between the primary winding and the secondary winding, which can effectively reduce the electromagnetic field coupling between the primary and secondary windings, reduce common-mode interference and differential-mode interference, and improve the electromagnetic compatibility of the transformer; at the same time, it also helps to reduce the leakage inductance and parasitic capacitance between the primary and secondary windings, and improve the safety and stability of the transformer.

[0013] As described above, in a groundless transformer, the primary winding starts at the same-name end of the primary winding and ends at the opposite-name end of the primary winding. The primary winding is made by tightly winding a single conductor multiple times.

[0014] By adopting the above technical solution, the primary winding, as the last layer of winding, can be as close as possible to the secondary winding, increasing the effective coupling area and reducing leakage inductance and parasitic capacitance between the primary and secondary windings. Secondly, the primary winding is located on the outer layer of the transformer, with better heat dissipation conditions, which can effectively reduce the temperature rise caused by copper loss and improve the heat dissipation capacity of the transformer.

[0015] In the above-described groundless transformer, an insulating layer is provided between the auxiliary winding and the secondary winding, between the auxiliary winding and the shielding layer winding, and between the shielding layer winding and the primary winding.

[0016] By adopting the above technical solutions, the insulation layer can reduce electromagnetic interference between windings, improve the electromagnetic compatibility of the transformer, reduce heat conduction between windings, reduce the risk of local overheating, improve the thermal stability of the transformer, and extend its service life.

[0017] As described above, in a groundless transformer, the insulating bushing is a Teflon bushing, and the insulating layer is made of two layers of insulating tape.

[0018] In the above-described groundless transformer, the conductors used for winding the auxiliary winding, secondary winding, shielding layer winding, and primary winding are all enameled copper wires.

[0019] Compared with the prior art, the groundless transformer proposed in this utility model has the following advantages: 1. The transformer proposed in this utility model, by setting an insulating bushing at the starting end of the primary winding, can effectively isolate the primary winding from other windings or magnetic cores, preventing high-voltage breakdown and other situations. At the same time, the insulating bushing's isolation function can reduce parasitic capacitance and leakage inductance between the primary winding and other windings, optimize the transformer's electromagnetic compatibility, and thus replace the grounding wire of the shielding winding. This avoids the short circuit phenomenon between transformer pins that is easily caused by the grounding wire of the shielding winding. Moreover, this winding method is relatively simple, easy to automate production, and improves the production efficiency of the transformer.

[0020] 2. The transformer proposed in this utility model, by winding the auxiliary winding, secondary winding, shielding layer winding and primary winding in sequence, can have the secondary winding wound inside, effectively reducing the winding length, thereby reducing copper loss and heat generation. Although the winding length of the outermost primary winding is relatively long, the heat dissipation conditions are better due to the insulating sleeve at the starting end of the primary winding, which can effectively reduce the temperature rise caused by copper loss, thereby improving the heat dissipation capacity of the transformer. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0021] Figure 1 This is a schematic diagram of the winding structure of this utility model; Figure 2 This is a schematic diagram of the electrical polarity of this utility model; Figure 3 This is a front view of the product structure of this utility model; Figure 4 This is a schematic diagram of the first magnetic core structure of this utility model; Figure 5 This is a side view of the product structure of this utility model; Figure 6 This is a bottom view of the product structure of this utility model. Detailed Implementation To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0022] Specific embodiments, combined with Figures 1 to 6 As shown, the technical solution of this utility model is further explained. A groundless transformer includes a frame 10 and a magnetic core body 20 fixed on the frame 10. An auxiliary winding N1, a secondary winding N2, a shielding layer winding N3 and a primary winding N4 are wound sequentially on the magnetic core body 20. The starting end of the primary winding N4 is provided with an insulating sleeve 30 for providing insulation protection, so as to eliminate the grounding wire of the shielding layer winding N3.

[0023] The insulating sleeve 30 includes, but is not limited to, Teflon sleeves and insulating fiber sleeves. Preferably, the insulating sleeve 30 is a Teflon sleeve.

[0024] In this embodiment, the insulating sleeve 30 installed at the starting end of the primary winding N4 can effectively isolate the primary winding N4 from other windings or magnetic cores, preventing high-voltage breakdown and other situations. At the same time, the insulating sleeve 30 can reduce the parasitic capacitance and leakage inductance between the primary winding N4 and other windings, optimize the electromagnetic compatibility of the transformer, and thus replace the grounding wire of the shielding winding N3. This avoids the short circuit phenomenon between transformer pins that is easily caused by the grounding wire of the shielding winding. Moreover, this winding method is relatively simple, easy to automate, and improves the production efficiency of the transformer.

[0025] Furthermore, as a preferred embodiment of this solution and not a limitation, the magnetic core body 20 includes a first magnetic core 21 and a second magnetic core 22 corresponding to the first magnetic core 21. An adhesive dispensing position 23 is provided at the core column of the first magnetic core 21 and the second magnetic core 22 for dispensing adhesive to fix it onto the skeleton 10.

[0026] As a preferred implementation method, such as Figure 4 As shown, the adhesive dispensing position 23 is set on the core column of the first magnetic core 21. Of course, the adhesive dispensing position 23 can also be set on the core column of the second magnetic core 22. The specific setting position can be adjusted according to the actual situation. This embodiment uses setting the adhesive dispensing position 23 on the first magnetic core 21 as an example for illustration. When applying the adhesive, the adhesive should cover 2 / 3 of the area of ​​the central column of the first magnetic core 21, so that when it is fixed to the skeleton 10, it can fill the air gap between the first magnetic core 21 and the second magnetic core 22.

[0027] Alternatively, the adhesive may include, but is not limited to, epoxy resin, silicone, and polyurethane adhesive; preferably, the adhesive 24 is epoxy resin.

[0028] In this embodiment, the setting of the adhesive dispensing position allows for better fixation of the first magnetic core 21 and the second magnetic core 22 when they are fixed to the frame 10. This stabilizes the magnetic core contact surface between the two magnetic cores and prevents misalignment and loosening of the magnetic cores. At the same time, the adhesive dispensing can fill the air gap between the first magnetic core 21 and the second magnetic core 22, thereby preventing the magnetic core body from vibrating under the action of the magnetic field and reducing the noise of the transformer.

[0029] Furthermore, as a preferred embodiment of this solution and not a limitation, the auxiliary winding N1 starts at the same end of the auxiliary winding N1 (i.e., the first pin in this embodiment) and ends at the same end of the shielding layer winding N3 (i.e., the second pin in this embodiment). The auxiliary winding N1 is made by tightly winding a single wire multiple times.

[0030] In a preferred embodiment, the auxiliary winding N1 is made by tightly winding a single wire 30 times. The diameter of the wire used to wind the auxiliary winding N1 is 0.21mm. In specific implementation, the wire gauge and the number of turns used to wind the primary winding N1 can be adjusted according to the actual product specifications and design requirements.

[0031] In this embodiment, the auxiliary winding N1 is wound first as the first layer of winding, which can provide a basic insulation layer for the subsequently wound primary winding N4 and secondary winding N2, reducing electromagnetic interference between the subsequently wound primary winding N4 and secondary winding N2; at the same time, it can also allow the subsequently wound primary winding N4 and secondary winding N2 to be wound more tightly, increasing the effective coupling area between the windings, thereby reducing leakage inductance and improving the efficiency of the transformer.

[0032] Furthermore, as a preferred embodiment of this solution and not a limitation, the secondary winding N2 starts at the same-name end of the secondary winding N2 (i.e., pin 7 in this embodiment) and ends at the opposite-name end of the secondary winding N2 (i.e., pin 8 in this embodiment), and the secondary winding N2 is made by tightly winding a single wire multiple times.

[0033] In a preferred embodiment, the secondary winding N2 is made by tightly winding a single wire 15 turns. The diameter of the wire used to wind the secondary winding N2 is 0.4 mm. In specific implementations, the wire gauge and the number of turns of the wire used to wind the secondary winding N2 can be adjusted according to the actual product specifications and design requirements.

[0034] In this embodiment, the secondary winding N2 is wound before the primary winding N4. The purpose of this is that the copper loss of the secondary winding N2 is more sensitive to the wire length. By winding the secondary winding N2 on the inside, the winding length can be effectively reduced, thereby reducing copper loss and heat generation. Although the winding length of the outer primary winding N4 is longer, it is located on the outer layer of the transformer and has an insulating sleeve 30 at the starting end, which provides better heat dissipation conditions. This can effectively reduce the temperature rise caused by copper loss and thus improve the heat dissipation capacity of the transformer.

[0035] Furthermore, as a preferred embodiment of this solution and not a limitation, the shielding layer winding N3 starts at the same-name end of the shielding layer winding N3 (i.e., the second pin in this embodiment) and ends at the opposite-name end of the shielding layer winding N3 (i.e., the third pin in this embodiment). The shielding layer winding N3 is made by tightly winding a single wire multiple times.

[0036] In a preferred embodiment, the shielding layer winding N3 is made by tightly winding a single wire 12 turns. The diameter of the wire used to wind the shielding layer winding N3 is 0.21 mm. In specific implementations, the wire gauge and the number of turns of the wire used to wind the shielding layer winding N3 can be adjusted accordingly based on the actual product specifications and design requirements.

[0037] In this embodiment, the shielding layer winding N3 is disposed between the primary winding N4 and the secondary winding N2, which can effectively reduce the electromagnetic field coupling between the primary and secondary windings, reduce common-mode interference and differential-mode interference, and improve the electromagnetic compatibility of the transformer; at the same time, it also helps to reduce the leakage inductance and parasitic capacitance between the primary and secondary windings, and improve the safety and stability of the transformer.

[0038] Furthermore, as a preferred embodiment of this solution and not a limitation, the primary winding N4 starts at the same-name end of the primary winding N4 (i.e., pin 4 in this embodiment) and ends at the opposite-name end of the primary winding N4 (i.e., pin 5 in this embodiment), and the primary winding N4 is made by tightly winding a single wire multiple times.

[0039] In a preferred embodiment, the primary winding N4 is made by tightly winding a single wire 6 turns. The diameter of the wire used to wind the primary winding N4 is 0.15mm. In specific implementation, the wire gauge and the number of turns of the wire used to wind the primary winding N4 can be adjusted accordingly based on the actual product specifications and design requirements. When winding the primary winding N4, care should be taken to ensure that it is centered and tightly wound.

[0040] In this embodiment, the primary winding N4 is the last layer of winding, which can be as close as possible to the secondary winding N2, increasing the effective coupling area, improving the coupling coefficient between the primary and secondary windings, and improving the energy transmission efficiency. Secondly, the primary winding N4 is located on the outer layer of the transformer, which has better heat dissipation conditions, effectively reducing the temperature rise caused by copper loss and improving the heat dissipation capacity of the transformer.

[0041] Furthermore, as a preferred embodiment of this solution and not a limitation, an insulating layer 40 is provided between the auxiliary winding N1 and the secondary winding N2, between the auxiliary winding N2 and the shielding layer winding N3, and between the shielding layer winding N3 and the primary winding N1. The insulating layer 40 is made of two layers of insulating tape.

[0042] In this embodiment, the insulation layer can reduce electromagnetic interference between windings, improve the electromagnetic compatibility of the transformer, reduce heat conduction between windings, reduce the risk of local overheating, improve the thermal stability of the transformer and extend its service life. In addition, the insulation layer increases the spacing between windings, thereby reducing the coupling effect between windings and reducing the common-mode current between windings.

[0043] Furthermore, as a preferred embodiment of this solution and not a limitation, the conductors used for winding the auxiliary winding N1, secondary winding N2, shielding layer winding N3, and primary winding N4 are all enameled copper wires. In specific implementations, other wires may also be used.

[0044] Furthermore, as a preferred embodiment of this solution and not a limitation, the model of the skeleton 10 includes, but is not limited to, EDR3910 and EDR3910. Preferably, the model of the skeleton 10 is EDR3910.

[0045] The working principle of this utility model is as follows: This utility model proposes a groundless transformer. By setting an insulating bushing 30 at the starting end of the primary winding N4, the primary winding N4 can be effectively isolated from other windings or magnetic cores, preventing high-voltage breakdown and other situations. At the same time, the isolation effect of the insulating bushing 30 can reduce the parasitic capacitance and leakage inductance between the primary winding N4 and other windings, optimize the electromagnetic compatibility of the transformer, and thus replace the grounding wire of the shielding winding N3, avoiding the short circuit phenomenon between transformer pins that is easily caused by the grounding wire of the shielding winding. Secondly, the winding sequence is as follows: first, the auxiliary winding N1 is wound; after the auxiliary winding N1 is wound, the secondary winding N2 is wound; after the secondary winding N2 is wound, the shielding layer winding N3 is wound; and finally, the primary winding N4 is wound. Through this winding method, the secondary winding N2 can be wound on the inside, effectively reducing the winding length, thereby reducing copper loss and heat generation. Although the primary winding N4 on the outermost layer has a longer winding length, the primary winding N4 has a good heat dissipation condition due to the insulating sleeve 30 at the starting end, which can effectively reduce the temperature rise caused by copper loss, thereby improving the heat dissipation capacity of the transformer.

[0046] Those skilled in the art should understand that the above description is one embodiment provided in conjunction with specific content, and does not imply that the specific implementation of this utility model is limited to these descriptions. Furthermore, due to differences in industry naming conventions, it is not limited to the above names or English names. Any methods or structures similar to or identical to those of this utility model, or any technical deductions or substitutions made based on the concept of this utility model, should be considered within the scope of protection of this utility model.

Claims

1. A groundless transformer, characterized in that, It includes a frame (10) and a magnetic core body (20) fixed on the frame (10). The magnetic core body (20) is wound with an auxiliary winding N1, a secondary winding N2, a shielding layer winding N3 and a primary winding N4 in sequence. The starting end of the primary winding N4 is provided with an insulating sleeve (30) for providing insulation protection, in place of the grounding wire of the shielding layer winding N3.

2. A groundless transformer according to claim 1, characterized in that, The magnetic core body (20) includes a first magnetic core (21) and a second magnetic core (22) corresponding to the first magnetic core (21). A dispensing position (23) for dispensing glue to fix the first magnetic core (21) and the second magnetic core (22) to the frame (10) is provided at the magnetic core column.

3. A groundless transformer according to claim 2, characterized in that, When applying the adhesive, the adhesive on the dispensing position (23) should cover 2 / 3 of the area of ​​the magnetic core column, and the adhesive is epoxy resin.

4. A groundless transformer according to claim 1, characterized in that, The auxiliary winding N1 starts at the same end as the shielding layer winding N3 and ends at the same end as the shielding layer winding N3. The auxiliary winding N1 is made by tightly winding a single wire multiple times.

5. A groundless transformer according to claim 1, characterized in that, The secondary winding N2 starts at the same-name end of the secondary winding N2 and ends at the opposite-name end of the secondary winding N2. The secondary winding N2 is made by tightly winding a single wire multiple times.

6. A groundless transformer according to claim 1, characterized in that, The shielding layer winding N3 starts at the same-name end of the shielding layer winding N3 and ends at the opposite-name end of the shielding layer winding N3. The shielding layer winding N3 is made by tightly winding a single wire multiple times.

7. A groundless transformer according to claim 1, characterized in that, The primary winding N4 starts at the same-name end of the primary winding N4 and ends at the opposite-name end of the primary winding N4. The primary winding N4 is made by tightly winding a single wire multiple times.

8. A groundless transformer according to claim 1, characterized in that, An insulating layer (40) is provided between the auxiliary winding N1 and the secondary winding N2, between the auxiliary winding N2 and the shielding layer winding N3, and between the shielding layer winding N3 and the primary winding N1.

9. A groundless transformer according to claim 8, characterized in that, The insulating sleeve (30) is a Teflon sleeve, and the insulating layer (40) is made of two layers of insulating tape.

10. A groundless transformer according to claim 1, characterized in that, The conductors used for winding the auxiliary winding N1, secondary winding N2, shielding layer winding N3 and primary winding N4 are all enameled copper wires.

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