A bushless transformer
By using a sleeveless electrostatic shielding layer and adhesive fixing, the problems of high production difficulty and electromagnetic compatibility of transformers were solved, achieving automated production and high electromagnetic compatibility.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHONGSHAN HONGHUA ELECTRONICS CO LTD
- Filing Date
- 2025-05-28
- Publication Date
- 2026-07-21
AI Technical Summary
Adding insulating bushings to the secondary winding side of existing transformers makes production difficult and complex, hinders automated production, and poses electromagnetic compatibility issues.
The design adopts a sleeveless design. By providing a lead wire at the starting end of the shielding layer winding to the bottom of the magnetic core body, an electrostatic shielding layer is formed, which reduces the interference signal transmission between the primary and secondary windings. The magnetic core is fixed by dispensing, which simplifies the winding process and eliminates the need for the secondary winding insulation sleeve.
It effectively reduces electromagnetic interference, improves production efficiency, stabilizes the magnetic core contact surface, prevents magnetic core loosening, simplifies the production process, and improves the electromagnetic compatibility and production efficiency of transformers.
Smart Images
Figure CN224536852U_ABST
Abstract
Description
[Technical Field] This utility model relates to the field of transformer technology, and in particular to a bushing-less transformer. [Background Technology] A transformer is a device that uses the principle of electromagnetic induction to change alternating current voltage. A transformer typically consists of a primary winding and a secondary winding, which are coupled together via a magnetic core to achieve voltage transformation. However, in practical applications, due to the capacitive effect between the primary and secondary windings (i.e., interlayer capacitance), common-mode interference signals can easily propagate from the primary winding to the secondary winding. This not only affects the transformer's operating performance but may also lead to electromagnetic compatibility issues.
[0001] To suppress common-mode interference, the traditional method is to add insulating bushings to the secondary winding side to improve the insulation strength between windings. However, adding insulating bushings to the secondary winding side increases the difficulty of transformer production and complicates the transformer manufacturing process, which is not conducive to automated production and leads to low transformer production efficiency. [Utility Model Content] To address the technical problem that the insulating bushings on the secondary winding side of current transformers make transformer production difficult and complex, thus hindering automated production, this utility model provides a bushing-free transformer.
[0002] To achieve the above objectives, this utility model is implemented by the following technical solution: A bushingless transformer includes a frame and a core body fixed on the frame. The core body has a primary winding, a shielding layer winding, a secondary winding, a compensation winding, and an auxiliary winding wound sequentially. The starting end of the shielding layer winding is provided with a lead wire connected to the bottom of the core body.
[0003] By adopting the above technical solution, a lead wire is provided at the starting end of the shielding layer winding to connect to the bottom of the magnetic core body, forming an electrostatic shielding layer. This can isolate interference signals between the primary and secondary windings, and return the common-mode interference signal of the primary winding to the interference source through the electrostatic shielding layer. This reduces the transmission of common-mode interference signals to the secondary winding through the interlayer capacitance between the primary and secondary windings, effectively reducing electromagnetic interference. As a result, the secondary winding does not need to be equipped with an additional insulating sleeve, making it easier to achieve automated production and improve the production efficiency of the transformer.
[0004] As described above, in a sleeveless transformer, the core body includes a first core and a second core corresponding to the first core, and a dispensing position for dispensing adhesive to fix it to the frame is provided at the core column of the first core and the second core.
[0005] As described above, in the case of a sleeveless 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 bushing-less transformer, the primary winding starts at the opposite end of the primary winding and ends at the same end of the primary winding, and the primary winding is made by tightly winding a single conductor multiple times.
[0008] By adopting the above technical solution, since the primary winding often carries a large current, winding the primary winding first can bring it closer to the core body. The core body is usually an iron core, which has good heat dissipation capacity, which helps to conduct and dissipate heat and improve the heat dissipation capacity of the transformer.
[0009] As described above, in a type of bushingless 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, and the shielding layer winding is made of two wires wound in parallel for multiple turns.
[0010] By adopting the above technical solution, placing the shielding layer winding between the primary and secondary windings can effectively reduce 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.
[0011] As described above, in a bushingless 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, and the secondary winding is made of two wires wound in parallel for multiple turns.
[0012] By adopting the above technical solutions, the secondary winding can reduce the distributed capacitance between windings and reduce losses at high frequencies, which helps to improve the working efficiency of the transformer at high frequencies. Secondly, the secondary winding eliminates the insulating bushing, which simplifies the winding process, makes it easier to achieve automated production, and improves the production efficiency of the transformer.
[0013] As described above, in a bushingless transformer, the compensation winding starts at the same end of the compensation winding and ends at the same end of the shielding layer winding. The compensation winding is made of two wires wound in parallel for multiple turns.
[0014] By adopting the above technical solution, the compensation winding can compensate the output voltage of the high-frequency transformer to offset the voltage deviation caused by load changes or input voltage fluctuations, thereby improving the stability and accuracy of the output voltage.
[0015] As described above, in a bushingless transformer, the auxiliary winding starts at the same end as the primary winding and ends at the same end as the auxiliary winding. The auxiliary winding is made by tightly winding a single conductor multiple times.
[0016] By adopting the above technical solution, the auxiliary winding can provide the required power supply voltage for the control circuit, protection circuit, etc., to ensure the normal operation of these circuits. When the secondary winding output is overloaded, the output voltage of the auxiliary winding will drop, protecting the switching transistor and other components from burning out due to output overload.
[0017] As described above, in a bushing-less transformer, an insulating layer is provided between the primary winding and the shielding layer winding, between the shielding layer winding and the secondary winding, between the secondary winding and the compensation winding, and between the compensation winding and the auxiliary winding. The insulating layer is made of two layers of insulating tape.
[0018] 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.
[0019] As described above, in a bushingless transformer, the conductors used for winding the primary winding, shielding layer winding, secondary winding, compensation winding, and auxiliary winding are all enameled copper wires.
[0020] Compared with the prior art, the bushing-less transformer proposed in this utility model has the following beneficial effects: 1. The transformer proposed in this utility model has a lead wire at the starting end of the shielding layer winding connected to the bottom of the magnetic core body, forming an electrostatic shielding layer. This layer can isolate interference signals between the primary and secondary windings, and return the common-mode interference signal of the primary winding to the interference source through the electrostatic shielding layer. It also reduces the transmission of common-mode interference signals to the secondary winding through the interlayer capacitance between the primary and secondary windings, effectively reducing electromagnetic interference. As a result, the secondary winding does not need to be equipped with an additional insulating sleeve, making it easier to achieve automated production and improve the production efficiency of the transformer.
[0021] 2. The transformer proposed in this utility model is provided with a dotted epoxy resin area, which allows the first and second magnetic cores to be better fixed by dotting epoxy resin when fixing them to the frame, 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 dotted 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.
[0022] 3. The transformer proposed in this utility model is also equipped with a compensation winding, which can compensate for the output voltage of the high-frequency transformer to offset the voltage deviation caused by load changes or input voltage fluctuations, thereby improving the stability and accuracy of the output voltage. [Attached Image 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.
[0023] 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 planar 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 Methods
[0024] Specific embodiments, combined with Figures 1 to 6 As shown, the technical solution of this utility model is further explained. A sleeveless transformer includes a frame 10 and a magnetic core body 20 fixed on the frame 10. The magnetic core body 20 is wound with a primary winding N1, a shielding layer winding N2, a secondary winding N3, a compensation winding N4 and an auxiliary winding N5 in sequence. The starting end of the shielding layer winding N2 is provided with a lead wire 30 connected to the bottom of the magnetic core body 20.
[0025] In this embodiment, a lead wire 30 is provided at the starting end of the shielding layer winding N2, which is connected to the bottom of the magnetic core body 20 to form an electrostatic shielding layer. This layer can isolate interference signals between the primary and secondary windings, and return the common-mode interference signal of the primary winding N1 to the interference source through the electrostatic shielding layer. This reduces the transmission of common-mode interference signals to the secondary winding N3 through the interlayer capacitance between the primary and secondary windings, effectively reducing electromagnetic interference. As a result, the secondary winding N3 does not need to be equipped with an additional insulating sleeve, making it easier to achieve automated production and improve the production efficiency of the transformer.
[0026] 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.
[0027] 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.
[0028] Alternatively, the adhesive may include, but is not limited to, epoxy resin, silicone, and polyurethane adhesive; preferably, the adhesive 24 is epoxy resin.
[0029] 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.
[0030] Furthermore, as a preferred embodiment of this solution and not a limitation, the primary winding N1 starts at the opposite end of the primary winding N1 (i.e., the second pin in this embodiment) and ends at the same end of the primary winding N1 (i.e., the third pin in this embodiment). The primary winding N1 is made by tightly winding a single wire multiple times.
[0031] In a preferred embodiment, the primary winding N1 is made by tightly winding a single wire 56 times. The diameter of the wire used to wind the primary winding N1 is 0.25mm. In specific implementations, the wire gauge and the number of turns of the wire used to wind the primary winding N1 can be adjusted according to the actual product specifications and design requirements.
[0032] In this embodiment, since the primary winding N1 often carries a large current, winding the primary winding N1 first can bring it closer to the core body 20. The core body 20 is usually an iron core, which has good heat dissipation capacity, which helps to conduct and dissipate heat and improve the heat dissipation capacity of the transformer.
[0033] Furthermore, as a preferred embodiment of this solution and not a limitation, the shielding layer winding N2 starts at the same-name end of the shielding layer winding N2 (i.e., pin 5 in this embodiment) and ends at the opposite-name end of the shielding layer winding N2 (i.e., pin NC in this embodiment). The shielding layer winding N2 is made by winding multiple turns of two wires in parallel.
[0034] After the shielding layer winding N2 is wound, its take-up end is wrapped inside the enameled wire as a shielding wire and is not connected to the opposite-name end (i.e., NC pin) of the shielding layer winding N2.
[0035] In a preferred embodiment, the shielding layer winding N2 is made by double-wire parallel winding with 19 turns. The diameter of the wire used to wind the primary winding N1 is 0.15mm. In specific implementation, the wire gauge and the number of turns used to wind the shielding layer winding N2 can be adjusted according to the actual product specifications and design requirements.
[0036] In this embodiment, the shielding layer winding N2 is disposed between the primary winding N1 and the secondary winding N3, 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.
[0037] Furthermore, as a preferred embodiment of this solution and not a limitation, the secondary winding N3 starts at the same-name end of the secondary winding N3 (i.e., pin 7 in this embodiment) and ends at the opposite-name end of the secondary winding N3 (i.e., pin 6 in this embodiment), and the secondary winding N3 is made by winding two wires in parallel multiple times.
[0038] After the secondary winding N3 is wound, its take-up end is attached to the opposite end of the secondary winding (i.e., pin 6).
[0039] In a preferred embodiment, the secondary winding N3 is made by double-wire parallel winding with 5 turns. The diameter of the wire used to wind the secondary winding N3 is 0.55mm. In specific implementation, the wire gauge and the number of turns of the wire used to wind the secondary winding N3 can be adjusted according to the actual product specifications and design requirements.
[0040] In this embodiment, the secondary winding N3 adopts a double-wire parallel winding method, which can reduce the distributed capacitance between windings, reduce losses at high frequencies, and help improve the working efficiency of the transformer when operating at high frequencies. Secondly, the secondary winding N3 eliminates the insulating bushing, which can simplify the winding process, make it easier to achieve automated production, and improve the production efficiency of the transformer.
[0041] Furthermore, as a preferred embodiment of this solution and not a limitation, the compensation winding N4 starts at the same end as the compensation winding N4 (i.e., pin 4 in this embodiment) and ends at the same end as the shielding layer winding N2 (i.e., pin 5 in this embodiment). The compensation winding N4 is made by winding two wires in parallel multiple times.
[0042] In a preferred embodiment, the compensation winding N4 is made by double-wire parallel winding with 12 turns. The diameter of the wire used to wind the compensation winding N4 is 0.15mm. In specific implementation, the wire gauge and the number of turns of the wire used to wind the compensation winding N4 can be adjusted according to the actual product specifications and design requirements.
[0043] In this embodiment, the compensation winding N4 can compensate the output voltage of the high-frequency transformer to offset the voltage deviation caused by load changes or input voltage fluctuations, thereby improving the stability and accuracy of the output voltage. Secondly, the compensation winding N4 can reduce the leakage inductance and distributed capacitance of the high-frequency transformer, which helps to improve the electromagnetic compatibility of the transformer and reduce interference to surrounding equipment.
[0044] Furthermore, as a preferred embodiment of this solution and not a limitation, the auxiliary winding N5 starts at the same end as the primary winding N1 (i.e., the third pin in this embodiment) and ends at the same end as the auxiliary winding N5 (i.e., the first pin in this embodiment). The auxiliary winding N5 is made by tightly winding a single wire multiple times.
[0045] In a preferred embodiment, the auxiliary winding N5 is made by tightly winding a single wire 25 turns. The diameter of the wire used to wind the auxiliary winding N5 is 0.25mm. In specific implementations, the wire gauge and the number of turns of the wire used to wind the auxiliary winding N5 can be adjusted accordingly based on the actual product specifications and design requirements.
[0046] In this embodiment, the auxiliary winding N5 can provide the required power supply voltage for the control circuit, protection circuit, etc., to ensure the normal operation of these circuits. When the secondary winding N3 is overloaded, the output voltage of the auxiliary winding N5 will drop, protecting the switching transistor and other components from burning out due to the overload. Secondly, the auxiliary winding N5 is located on the outermost layer, and its distributed capacitance with the primary winding N1 is relatively small, which can reduce high-frequency interference and improve the electromagnetic compatibility of the transformer.
[0047] Furthermore, as a preferred embodiment of this solution and not a limitation, an insulating layer 40 is provided between the primary winding N1 and the shielding layer winding N2, between the shielding layer winding N2 and the secondary winding N3, between the secondary winding N3 and the compensation winding N4, and between the compensation winding N4 and the auxiliary winding N5. The insulating layer 40 is made of two layers of insulating tape. In addition, the outer layer of the auxiliary winding N5 may also be provided with an insulating layer 40.
[0048] 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.
[0049] Furthermore, as a preferred embodiment of this solution and not a limitation, the conductors used for winding the primary winding N1, the shielding layer winding N2, the secondary winding N3, the compensation winding N4, and the auxiliary winding N5 are all enameled copper wires. In specific implementations, other wires may also be used.
[0050] Furthermore, as a preferred embodiment of this solution and not a limitation, the model of the skeleton 10 includes, but is not limited to, EE16, EE19, and ER25. Preferably, the model of the skeleton 10 is EE16.
[0051] The working principle of this utility model is as follows: This utility model proposes a sleeveless transformer, whose winding sequence is as follows: first, the primary winding N1 is wound; after the primary winding N1 is wound, the shielding layer winding N2 is wound; after the shielding layer winding N2 is wound, the secondary winding N3 is wound; after the secondary winding N3 is wound, the compensation winding N4 is wound; and finally, the auxiliary winding N5 is wound. The starting end of the shielding layer winding N2 is also provided with a lead wire 30 connected to the bottom of the magnetic core body 20. Since the shielding layer winding N2 itself has a shielding effect, it can reduce the electromagnetic field coupling between the primary and secondary windings. In addition, the lead wire 30 at the starting end of the shielding layer winding N2 connected to the bottom of the magnetic core body 20 forms an electrostatic shielding layer, which isolates interference signals between the primary and secondary windings. Therefore, the secondary winding N3 does not require an additional insulating sleeve, making it easier to achieve automated production and improving the production efficiency of the transformer.
[0052] 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 bushingless transformer, characterized in that, The device includes a frame (10) and a core body (20) fixed on the frame (10). The core body (20) is wound with a primary winding N1, a shielding layer winding N2, a secondary winding N3, a compensation winding N4 and an auxiliary winding N5 in sequence. The starting end of the shielding layer winding N2 is provided with a lead wire (30) connected to the bottom of the core body (20).
2. The bushingless 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 bushing-less 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 bushing-less transformer according to claim 1, characterized in that, The primary winding N1 starts at the opposite end of the primary winding N1 and ends at the same end of the primary winding N1. The primary winding N1 is made by tightly winding a single wire multiple times.
5. A bushing-less transformer according to claim 1, characterized in that, The shielding layer winding N2 starts at the same-name end of the shielding layer winding N2 and ends at the opposite-name end of the shielding layer winding N2. The shielding layer winding N2 is made by winding multiple turns of two wires in parallel.
6. A bushingless transformer according to claim 1, characterized in that, The secondary winding N3 starts at the same-name end of the secondary winding N3 and ends at the opposite-name end of the secondary winding N3. The secondary winding N3 is made by winding two wires in parallel for multiple turns.
7. A bushingless transformer according to claim 1, characterized in that, The compensation winding N4 starts at the same end of the compensation winding N4 and ends at the same end of the shielding layer winding N2. The compensation winding N4 is made by winding multiple turns of two wires in parallel.
8. A bushing-less transformer according to claim 1, characterized in that, The auxiliary winding N5 starts at the same end as the primary winding N1 and ends at the same end as the auxiliary winding N5. The auxiliary winding N5 is made by tightly winding a single wire multiple times.
9. A bushingless transformer according to claim 1, characterized in that, An insulating layer (40) is provided between the primary winding N1 and the shielding layer winding N2, between the shielding layer winding N2 and the secondary winding N3, between the secondary winding N3 and the compensation winding N4, and between the compensation winding N4 and the auxiliary winding N5. The insulating layer (40) is made of two layers of insulating tape.
10. A bushing-less transformer according to claim 1, characterized in that, The wires used for winding the primary winding N1, shielding winding N2, secondary winding N3, compensating winding N4 and auxiliary winding N5 are all enameled copper wires.