Transformer and home appliance

Abstract

The utility model discloses a transformer and home electrical equipment relates to transformer technical field. Transformer includes core, primary winding, secondary winding and at least one magnetic leakage sheet, and the core includes the upper yoke of head connection in proper order, first side yoke, lower yoke and second side yoke, and the center column is connected in the upper yoke and lower yoke. Since primary winding is set on the center column, and the high voltage winding of secondary winding is set on the outside of primary winding, so that the primary winding and high voltage winding can have higher height as a whole, and the thickness is reduced. Therefore, the average circumference required by each circle of primary winding and high voltage winding when winding is reduced, and the material usage required under the condition of the same number of turns is reduced, which can reduce the manufacturing cost. Since the high voltage winding is located on the outside of the primary winding, the high voltage winding is the main heat source, and the heat dissipation area is larger under the condition of increased height and reduced thickness, which can improve the heat dissipation performance and reduce the operating temperature rise of the transformer.

Description

Technical Field

[0001] This utility model relates to the field of transformer technology, and in particular to a transformer and a household appliance. Background Technology

[0002] Microwave oven EI-type leakage inductance high-voltage transformers typically employ a vertically stacked winding structure, where the primary winding, filament winding, and high-voltage winding are wound sequentially in segments along the axial direction of the core's central column. This layout results in each winding occupying a limited winding height, leading to a shorter and thicker cross-section, increased average turn length, and a larger number of windings, thus increasing costs. Furthermore, the concentrated stacking of all heat sources, tightly encased on three sides of the core, makes it difficult for the heat generated by the windings to be effectively conducted and dissipated via convection, resulting in a higher overall transformer temperature rise and impacting the transformer's reliability and lifespan. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a transformer that can reduce the amount of material used in the windings, lower costs, and improve heat dissipation performance, thereby reducing the operating temperature rise of the transformer.

[0004] This utility model also proposes a household appliance having the above-mentioned transformer.

[0005] A transformer according to a first aspect of the present invention includes: an iron core, comprising an upper yoke, a first side yoke, a lower yoke, and a second side yoke connected end to end; the iron core further includes a center post, the center post being located between the first side yoke and the second side yoke, and the center post being connected to the upper yoke and the lower yoke respectively. A primary winding is fitted onto the central post; The secondary winding includes a high-voltage winding and a filament winding. The high-voltage winding is sleeved on the outside of the primary winding and spaced apart from the primary winding. The filament winding is located at the end of the primary winding facing the upper yoke or the lower yoke and is sleeved on the central post. At least one magnetic leakage element is disposed between the high-voltage winding and the primary winding, with at least a portion of the structure of the magnetic leakage element located between the central post and the first side yoke, and / or at least a portion of the structure of the magnetic leakage element located between the central post and the second side yoke.

[0006] The transformer according to the embodiments of the present invention has at least the following beneficial effects: By placing a leakage flux sheet between the high-voltage winding and the primary winding, a portion of the main magnetic flux generated by the primary winding bypasses the high-voltage winding and returns directly through the leakage flux sheet, thus creating leakage inductance and limiting current. The filament winding is located at the end of the primary winding facing the upper or lower yoke, which facilitates insulation between it and both the primary and high-voltage windings. Since the primary winding is mounted on the center post, and the high-voltage winding of the secondary winding is mounted outside the primary winding, the overall height and thickness of the primary and high-voltage windings can be increased. Therefore, the average circumference required per turn of the primary and high-voltage windings is reduced, resulting in less material usage for the same number of turns and lower manufacturing costs. Because the high-voltage winding is located outside the primary winding, and is the primary heat source, its increased height and reduced thickness result in a larger heat dissipation area, improving heat dissipation performance and reducing the transformer's operating temperature rise.

[0007] According to some embodiments of the present invention, two magnetic leakage plates are provided, one of which is located between the first side yoke and the central column, and the other is located between the second side yoke and the central column.

[0008] According to some embodiments of the present invention, a first through hole is formed between the central column and the first side yoke, the upper yoke, and the lower yoke, and a second through hole is formed between the central column and the second side yoke, the upper yoke, and the lower yoke, wherein one of the magnetic leakage sheets is entirely located in the first through hole, and the other magnetic leakage sheet is entirely located in the second through hole.

[0009] According to some embodiments of the present invention, the filament winding is connected to the primary winding and the high-voltage winding on the side facing the upper yoke, a first insulating layer is provided on the outer side of the filament winding, and the filament winding is connected to the primary winding and the high-voltage winding through the first insulating layer.

[0010] According to some embodiments of the present invention, a first through hole is formed between the central column and the first side yoke, the upper yoke, and the lower yoke. The first through hole penetrates both sides of the iron core along a first direction. A second insulating layer is provided between the primary winding and the high-voltage winding along the first direction. The area enclosed by the second insulating layer, the primary winding, and the high-voltage winding is provided with the magnetic leakage sheet.

[0011] According to some embodiments of the present invention, a third insulating layer is provided around the outer circumferential wall of the high-voltage winding.

[0012] According to some embodiments of the present invention, a first through hole is formed between the central column and the first side yoke, the upper yoke, and the lower yoke. The first through hole penetrates both sides of the iron core along a first direction. The direction of the first side yoke toward the second side yoke is a second direction, and the second direction is perpendicular to the first direction. Along the first direction, the maximum gap between the primary winding and the high-voltage winding located outside the first through hole is H1, and along the second direction, the maximum gap between the primary winding and the high-voltage winding located inside the first through hole is H2, satisfying: H2 > H1.

[0013] According to some embodiments of the present invention, a fourth insulating layer is provided between the primary winding and the center post, the fourth insulating layer being connected to the primary winding and sleeved on the center post.

[0014] According to some embodiments of the present invention, the outer wall of the primary winding has four first corner portions, which are constructed as arc surfaces.

[0015] According to some embodiments of the present invention, the outer sidewall of the high-voltage winding has four second corner portions, the second corner portions being constructed as arc surfaces; and / or, the inner sidewall of the high-voltage winding has four third corner portions, the third corner portions being constructed as arc surfaces, the four third corner portions and the four first corner portions being arranged opposite to each other.

[0016] The household appliance according to a second aspect of the present invention includes the transformer described in the above embodiment.

[0017] The household appliances according to the embodiments of this utility model have at least the following beneficial effects: By employing the transformer of the first aspect embodiment, the transformer, through the placement of a leakage flux sheet between the high-voltage winding and the primary winding, allows a portion of the main magnetic flux generated by the primary winding to return directly through the leakage flux sheet instead of passing through the high-voltage winding, thereby creating leakage inductance and achieving current limiting. The filament winding is located at the end of the primary winding facing the upper or lower yoke, which facilitates insulation between it and both the primary and high-voltage windings. Since the primary winding is mounted on the center post, and the high-voltage winding of the secondary winding is mounted outside the primary winding, the overall height and thickness of the primary and high-voltage windings can be increased. Therefore, the average circumference required per turn of the primary and high-voltage windings is reduced, resulting in less material usage for the same number of turns and lower manufacturing costs. Because the high-voltage winding is located outside the primary winding, and is the primary heat source, its increased height and reduced thickness result in a larger heat dissipation area, improving heat dissipation performance and reducing the transformer's operating temperature rise.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of the structure of a transformer according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the iron core structure of one embodiment of the present invention; Figure 3 This is a front view of a transformer according to an embodiment of the present invention; Figure 4 yes Figure 3 Sectional view at point AA; Figure 5 This is a top view of a transformer according to an embodiment of the present invention; Figure 6 yes Figure 5 Sectional view at point BB.

[0020] Figure label: Transformer 1000; Core 100; Upper yoke 110; First side yoke 120; Lower yoke 130; Second side yoke 140; Central post 150; First through hole 160; Second through hole 170; Primary winding 200; Second insulation layer 210; Fourth insulation layer 220; First corner portion 230; Secondary winding 300; high voltage winding 310; third insulation layer 311; second corner section 312; third corner section 313; filament winding 320; 400mm magnetic leakage sheet. Detailed Implementation

[0021] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0022] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0023] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0024] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0025] In related technologies, EI-type leakage inductance high-voltage transformers for microwave ovens typically employ a vertically stacked winding structure, where the primary winding, filament winding, and high-voltage winding are wound sequentially in segments along the axial direction of the core's central column. This layout results in each winding encroaching on the limited winding height, leading to a shorter and thicker cross-section, increased average turn length, larger winding quantity, and higher costs. Simultaneously, the concentrated heat sources of all windings, tightly encased on three sides of the core, hinder effective heat conduction and convection dissipation, resulting in a higher overall transformer temperature rise and impacting operational reliability and lifespan.

[0026] To solve the above problems, refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, this embodiment proposes a transformer 1000, including a core 100, windings, and a leakage magnetic sheet 400. The core 100 is composed of an upper yoke 110, a first side yoke 120, a lower yoke 130, and a second side yoke 140 connected end-to-end. The core 100 also includes a center post 150, which is located between the first side yoke 120 and the second side yoke 140 and connects the upper yoke 110 and the lower yoke 130. The windings include a primary winding 200 and a secondary winding 300. The primary winding 200 is sleeved on the center post 150, and the secondary winding 300 includes a high-voltage winding 310 sleeved outside the primary winding 200 and a filament winding 320 located at the end of the primary winding 200. The leakage magnetic sheet 400 is disposed between the high-voltage winding 310 and the primary winding 200, with part of its structure located between the center post 150 and the side yoke.

[0027] The core 100 refers to a closed magnetic circuit frame made of magnetically conductive material, which can be formed by stacking silicon steel sheets to guide magnetic flux and form a circuit. The primary winding 200 refers to the main coil that inputs electrical energy, which can be wound with copper or aluminum wire and sleeved on the center post 150 to realize the transfer of electromagnetic induction energy. The high-voltage winding 310 refers to the secondary coil that outputs high voltage, which can be arranged around the outside of the primary winding 200, and formed concentrically by spacing to reduce the average turn length. The filament winding 320 refers to the auxiliary coil that provides low-voltage current to the load, which can be independently sleeved on the end of the center post 150 to avoid overlapping with the heat source of the main winding.

[0028] For example, the transformer 1000 in this embodiment is a leakage inductance high-voltage transformer used in a microwave oven. The transformer 1000 has two core functions: first, to boost the voltage, raising the household 220V AC power to approximately 2000V, the high voltage required for the magnetron (the core heating element of the microwave oven) to operate; second, to achieve current limiting and voltage regulation, providing a stable and limited operating current to the magnetron through its special "leakage inductance" design. The primary winding 200 serves as the input terminal of the transformer 1000 and is connected to the household 220V AC power supply. After being energized, the primary winding 200 generates an alternating magnetic field in the iron core 100, which is the energy source for the transformer 1000's operation. The secondary winding 300 includes a high-voltage winding 310 and a filament winding 320. The high-voltage winding 310 has a large number of turns; according to the principle of electromagnetic induction, the high-voltage winding 310 can induce approximately 2000V of high-voltage AC power, supplying the anode of the magnetron and providing energy for microwave generation. The filament winding 320 is a secondary winding with very few turns. The filament winding 320 induces a low voltage of 3-4V, which is used to heat the cathode of the magnetron. The filament can only emit electrons after it is heated, which is a prerequisite for the magnetron to work.

[0029] The leakage magnetic strip 400, which can be a leakage magnetic lamination, is the core component for achieving the "leakage inductance" function. The leakage magnetic strip 400 can be formed by stacking silicon steel sheets and is placed between the primary winding 200 and the secondary winding 300. The function of the leakage magnetic strip 400 is to provide a "shortcut" or "bypass" for the magnetic flux generated by the primary winding 200. When the primary winding 200 generates a magnetic field, most of the magnetic field will pass through the secondary winding 300 along the central column 150 loop – this part is the "main magnetic flux." However, due to the presence of the leakage magnetic strip 400, a portion of the magnetic field will "take a shortcut," returning directly through the leakage magnetic strip 400 without passing through the secondary winding 300. This "leaked" magnetic field is the leakage magnetic flux. It is this leakage magnetic flux that constitutes the high leakage inductance of the transformer 1000, achieving the aforementioned current limiting and voltage stabilization functions.

[0030] Because magnetrons are easily affected by current, their equivalent resistance changes drastically during startup and operation. Without current limiting, a huge current would instantly burn out the magnetron. Due to the presence of the leakage flux 400, the transformer 1000 can utilize its high leakage inductance to act as an inductor in series in the circuit. When the magnetron attempts to draw excessive current, this "equivalent inductance" generates a reverse voltage, thus limiting the current to a safe range and serving as a current limiter. Simultaneously, when the mains voltage fluctuates, because the core 100 operates in a deep magnetic saturation state, combined with the leakage inductance, the power output to the magnetron remains relatively stable, thus serving as a voltage regulator.

[0031] Through the above technical solution, since the primary winding 200 is mounted on the center column 150 and the high-voltage winding 310 of the secondary winding 300 is mounted outside the primary winding 200, the primary winding 200 and the high-voltage winding 310 can have a higher overall height and a reduced thickness. Therefore, the average circumference required per turn of the primary winding 200 and the high-voltage winding 310 is reduced, resulting in less material usage for the same number of turns, thus lowering manufacturing costs. Since the high-voltage winding 310 is located outside the primary winding 200 and is the main heat source, its increased height and reduced thickness result in a larger heat dissipation area, improving heat dissipation performance and reducing the operating temperature rise of the transformer 1000.

[0032] Reference Figure 4 and Figure 6 As shown in the embodiment of this utility model, there are two magnetic leakage sheets 400, one of which is located between the first side yoke 120 and the central column 150, and the other is located between the second side yoke 140 and the central column 150.

[0033] For example, two leakage magnetic plates 400 are respectively embedded in the space between the first side yoke 120, the second side yoke 140, and the center post 150, forming a symmetrical flux adjustment zone in the annular region between the high-voltage winding 310 and the primary winding 200. Due to the symmetrical arrangement of the laminations, the leakage magnetic impedance on both sides of the winding axis tends to be consistent, and the Lorentz force acting on the winding forms a symmetrical component in space, thereby reducing the force imbalance of the winding structure.

[0034] In this embodiment, by symmetrically arranging the leakage magnetic sheets 400 on both sides, the leakage magnetic flux forms a symmetrical loop on both sides of the central column 150, which effectively eliminates the magnetic field bias phenomenon, reduces the winding vibration amplitude, and suppresses the generation of high-frequency noise. At the same time, the balanced magnetic field distribution makes the eddy current loss in each region of the winding tend to be uniform, avoids the formation of local hot spots, and improves the operating stability of the transformer 1000.

[0035] Reference Figure 2 and Figure 4As shown in the embodiment of this utility model, a first through hole 160 is formed between the central column 150 and the first side yoke 120, upper yoke 110, and lower yoke 130, and a second through hole 170 is formed between the central column 150 and the second side yoke 140, upper yoke 110, and lower yoke 130. One magnetic leakage sheet 400 is entirely located in the first through hole 160, and the other magnetic leakage sheet 400 is entirely located in the second through hole 170.

[0036] For example, the two magnetic leakage plates 400 are completely embedded in the internal spaces of the first through hole 160 and the second through hole 170, respectively. The two sides of the magnetic leakage plates 400 along the first direction are flush with the end walls of the first through hole 160 and the second through hole 170, which effectively suppresses the vibration amplitude of the magnetic leakage plates 400 in the alternating magnetic field, reduces the mechanical noise of the transformer 1000 during operation, and avoids the wear of the insulation material caused by vibration, thereby improving the long-term reliability of the equipment.

[0037] Reference Figure 1 and Figure 6 As shown in the embodiment of this utility model, the filament winding 320 is connected to the primary winding 200 and the high voltage winding 310 on the side facing the upper yoke 110. The outer side of the filament winding 320 is provided with a first insulating layer, and the filament winding 320 is connected to the primary winding 200 and the high voltage winding 310 through the first insulating layer.

[0038] The first insulation layer refers to the insulating medium wrapped around the outer surface of the filament winding 320. It can be made of polyester film, polyimide tape or epoxy resin composite material laminated together, or it can be Nomex insulating paper. Its function is to establish an electrical isolation barrier between the filament winding 320 and the adjacent windings and the core 100.

[0039] For example, the filament winding 320 is arranged on top of the primary winding 200 and the high-voltage winding 310. The first insulating layer continuously covers the outer surface of the filament winding 320. The outer surfaces of the primary winding 200 and the high-voltage winding 310 can also be wrapped with insulating paper. The first insulating layer is fixedly connected to the outer insulating layer of the primary winding 200 and the high-voltage winding 310 by interlayer adhesive. This arrangement creates vertical insulation between the filament winding 320 and the high-voltage winding 310, while the dielectric strength of the first insulating layer withstands the potential difference between the filament winding 320 and the high-voltage winding 310.

[0040] Through the above technical solution, this embodiment effectively solves the problem of complex insulation structure between filament winding 320 and high-voltage winding 310. By combining physical isolation with single-layer insulation, the process difficulty is reduced while ensuring insulation reliability. In addition, the filament winding 320 is arranged in the top region of the winding, away from the area wrapped by the core 100, which is beneficial to optimizing the heat dissipation path of the winding.

[0041] Reference Figure 4 As shown in the embodiment of this utility model, a first through hole 160 is formed between the central column 150 and the first side yoke 120, upper yoke 110, and lower yoke 130. The first through hole 160 penetrates both sides of the core 100 along a first direction. Along the first direction, a second insulating layer 210 is provided between the primary winding 200 and the high-voltage winding 310. A magnetic leakage sheet 400 is provided in the area enclosed by the second insulating layer 210, the primary winding 200, and the high-voltage winding 310. The second insulating layer 210 refers to the isolation structure provided between the winding and the magnetic leakage sheet 400. It can be a polyimide film or an epoxy resin coating, or it can be Nomex insulating paper. Its function is to block the charge migration path between the high-voltage winding 310 and the primary winding 200. The second insulating layer 210 can withstand the huge potential difference between the primary winding 200 and the high-voltage winding 310, preventing arc breakdown between the primary winding 200 and the high-voltage winding 310.

[0042] For example, there are two second insulating layers 210, located at both ends of the primary winding 200 along the first direction. The second insulating layer 210 is arranged in the annular gap between the primary winding 200 and the high-voltage winding 310. Under the action of the alternating electric field, a uniform electric field gradient distribution is formed inside the insulating layer, which effectively suppresses the generation of partial discharge phenomenon.

[0043] This embodiment, by setting a second insulation layer 210 at key locations between windings, not only achieves uniform potential distribution but also blocks potential conductive paths between windings. This solves the insulation failure problem caused by excessive potential difference between the high-voltage winding 310 and the primary winding 200, and avoids equipment damage caused by arc breakdown. This insulation structure makes the electric field distribution between windings more gradual, significantly improving the operational stability of the transformer 1000 under long-term high-voltage conditions.

[0044] Reference Figure 1 , Figure 4 and Figure 6 As shown in the embodiment of this utility model, a third insulating layer 311 is provided around the outer circumferential wall of the high-voltage winding 310. The third insulating layer 311 refers to an insulating material layer covering the outer surface of the high-voltage winding 310, which can be a polyimide film or an epoxy resin coating, or Nomex insulating paper, with a thickness of 0.2 mm to 0.5 mm. This insulating layer completely covers the outer surface of the high-voltage winding 310, blocking direct contact between the high-voltage winding 310 and the external environment. The third insulating layer 311 not only provides insulation protection but also protects the high-voltage winding 310 from physical damage, improving the reliability and durability of the transformer 1000.

[0045] Through the above technical solution, this embodiment forms an independent structural layer on the outside of the high-voltage winding 310, which combines insulation and protection functions. This avoids the risk of breakdown caused by insulation failure between windings and reduces direct damage to the windings from external physical factors, thereby extending the service life of the transformer 1000. Meanwhile, since both the primary winding 200 and the secondary winding 300 are wrapped with insulation layers, the leakage magnetic sheet 400 does not need an insulation layer, thus reducing the amount of insulation material used and lowering production costs while ensuring reliability.

[0046] Reference Figure 2 and Figure 4 As shown in the embodiment of this utility model, the direction of the first yoke 120 toward the second yoke 140 is the second direction, and the second direction is perpendicular to the first direction; along the first direction, the maximum gap between the primary winding 200 and the high-voltage winding 310 located outside the first through hole 160 is H1, and along the second direction, the maximum gap between the primary winding 200 and the high-voltage winding 310 located inside the first through hole 160 is H2, satisfying: H2 > H1.

[0047] The first direction refers to the direction in which the first through hole 160 passes through both sides of the core 100, which can be the front-back direction of the core 100. The second direction refers to the relative direction between the first yoke 120 and the second yoke 140, which can be the left-right direction of the core 100 and is perpendicular to the first direction.

[0048] By designing H2 to be greater than H1, a larger gap is formed in the longitudinal region between the high-voltage winding 310 and the primary winding 200, effectively reducing the risk of breakdown in the high electric field strength region. At the same time, the spatial layout in the transverse region is optimized to reduce winding length and material consumption, balancing insulation reliability and structural compactness.

[0049] Reference Figure 4 As shown in the embodiment of this utility model, a fourth insulating layer 220 is provided between the primary winding 200 and the center post 150. The fourth insulating layer 220 is connected to the primary winding 200 and sleeved on the center post 150. The fourth insulating layer 220 can be a polyimide film or an epoxy resin coating, or it can be Nomex insulating paper, with a thickness of 0.2mm to 0.5mm. By providing the fourth insulating layer 220 between the primary winding 200 and the center post 150, the fourth insulating layer 220 not only achieves reliable electrical isolation between the primary winding 200 and the ground core 100, ensuring product safety, but also serves as the winding skeleton of the primary winding 200, providing precise forming support for the winding and ensuring the consistency of the product's electrical parameters. In addition, the smooth surface of the fourth insulating layer 220 protects the enameled wire from damage during manufacturing and facilitates automated production, comprehensively improving product reliability and production efficiency.

[0050] Reference Figure 4 As shown in the embodiment of this utility model, the outer wall of the primary winding 200 has four first corner portions 230 arranged circumferentially around the primary winding 200, and the first corner portions 230 are constructed as arc surfaces. The first corner portion 230 refers to the corner area formed by the primary winding 200 in the circumferential direction. By designing the outer wall of the corner area as an arc shape, right angle or sharp corner structures are eliminated, stress concentration of the insulation material at the corner is reduced, and electric field concentration caused by sharp edges can be avoided, thereby reducing the risk of partial discharge or breakdown, improving the operating stability of the transformer 1000 under high voltage conditions, and extending the service life of the insulation material.

[0051] Reference Figure 4 As shown in the embodiment of this utility model, the outer wall of the high-voltage winding 310 has four second corner portions 312 arranged circumferentially around the high-voltage winding 310, and the second corner portions 312 are constructed as arc surfaces. And / or, the inner wall of the high-voltage winding 310 has four third corner portions 313 arranged circumferentially around the high-voltage winding 310, and the third corner portions 313 are constructed as arc surfaces. The four third corner portions 313 and the four first corner portions 230 are arranged opposite to each other. The arc surface refers to the structure in which the corner area adopts a rounded or chamfered transition. The radius of the arc can be adjusted according to the winding size and insulation requirements.

[0052] For example, the four second corner portions 312 and four third corner portions 313 provided in the high-voltage winding 310 can reduce the electric field distortion between it and the primary winding 200, and the rounded outer walls can reduce the electric field concentration between it and the outer insulation layer or the core 100. By constructing the inner and outer walls of the second corner portions 312 as rounded corners, the electric field distribution in the corner area tends to be uniform, avoiding the risk of partial discharge or breakdown caused by sharp corners, thereby improving the operating stability and service life of the transformer 1000 under high-voltage conditions.

[0053] This utility model discloses a household appliance according to one embodiment, including the transformer 1000 described in the above embodiment. The household appliance can be a microwave oven, a household sterilizer, a dish sterilizer, an air purifier, a water purifier, etc. The household appliance of this utility model uses the transformer 1000 described in the above embodiment. By setting a leakage magnetic sheet 400 between the high-voltage winding 310 and the primary winding 200, a portion of the main magnetic flux generated by the primary winding 200 does not pass through the high-voltage winding 310 but returns directly through the leakage magnetic sheet 400, thus forming leakage inductance and achieving current limiting. The filament winding 320 is located at the end of the primary winding 200 facing the upper yoke 110 or lower yoke 130, which facilitates insulation between it and the primary winding 200 and the high-voltage winding 310. Since the primary winding 200 is sleeved on the center post 150, and the high-voltage winding 310 of the secondary winding 300 is sleeved outside the primary winding 200, the primary winding 200 and the high-voltage winding 310 can have a higher overall height and a reduced thickness. Therefore, the average circumference required per turn of the primary winding 200 and the high-voltage winding 310 is reduced, resulting in less material usage for the same number of turns and lower manufacturing costs. Since the high-voltage winding 310 is located outside the primary winding 200 and is the primary heat source, its increased height and reduced thickness result in a larger heat dissipation area, improving heat dissipation performance and reducing the operating temperature rise of the transformer 1000.

[0054] Since the household appliances adopt all the technical solutions of the transformer 1000 in the above embodiments, they have at least all the beneficial effects brought about by the technical solutions in the above embodiments, which will not be repeated here.

[0055] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A transformer, characterized in that, include: The iron core includes an upper yoke, a first side yoke, a lower yoke, and a second side yoke connected end to end. The iron core also includes a central post located between the first side yoke and the second side yoke, and the central post is connected to the upper yoke and the lower yoke respectively. A primary winding is fitted onto the central post; The secondary winding includes a high-voltage winding and a filament winding. The high-voltage winding is sleeved on the outside of the primary winding and spaced apart from the primary winding. The filament winding is located at the end of the primary winding facing the upper yoke or the lower yoke and is sleeved on the central post. At least one magnetic leakage element is disposed between the high-voltage winding and the primary winding, with at least a portion of the structure of the magnetic leakage element located between the central post and the first side yoke, and / or at least a portion of the structure of the magnetic leakage element located between the central post and the second side yoke.

2. The transformer according to claim 1, characterized in that: The magnetic leakage sheet is provided in two parts, one of which is located between the first side yoke and the central column, and the other is located between the second side yoke and the central column.

3. The transformer according to claim 2, characterized in that: A first through hole is formed between the central column and the first side yoke, the upper yoke, and the lower yoke, and a second through hole is formed between the central column and the second side yoke, the upper yoke, and the lower yoke. One of the magnetic leakage plates is entirely located in the first through hole, and the other magnetic leakage plate is entirely located in the second through hole.

4. The transformer according to claim 1, characterized in that: The filament winding is connected to the primary winding and the high-voltage winding on the side facing the upper yoke. A first insulating layer is provided on the outer side of the filament winding, and the filament winding is connected to the primary winding and the high-voltage winding through the first insulating layer.

5. The transformer according to claim 1, characterized in that: A first through hole is formed between the central column and the first side yoke, the upper yoke, and the lower yoke. The first through hole extends through both sides of the iron core along a first direction. A second insulating layer is provided between the primary winding and the high-voltage winding along the first direction. The area enclosed by the second insulating layer, the primary winding, and the high-voltage winding is provided with the magnetic leakage sheet.

6. The transformer according to claim 1, characterized in that: The outer circumferential wall of the high-voltage winding is surrounded by a third insulating layer.

7. The transformer according to claim 1, characterized in that: A first through hole is formed between the central column and the first side yoke, the upper yoke, and the lower yoke. The first through hole extends through both sides of the iron core along a first direction. The direction of the first side yoke toward the second side yoke is a second direction, and the second direction is perpendicular to the first direction. Along the first direction, the maximum gap between the primary winding and the high-voltage winding located outside the first through hole is H1, and along the second direction, the maximum gap between the primary winding and the high-voltage winding located inside the first through hole is H2, satisfying: H2 > H1.

8. The transformer according to claim 1, characterized in that: A fourth insulating layer is provided between the primary winding and the center post, the fourth insulating layer being connected to the primary winding and sleeved on the center post.

9. The transformer according to claim 1, characterized in that: The outer wall of the primary winding has four first corners, which are constructed as arc surfaces.

10. The transformer according to claim 9, characterized in that: The outer sidewall of the high-voltage winding has four second corner portions, which are constructed as arc surfaces; and / or, the inner sidewall of the high-voltage winding has four third corner portions, which are constructed as arc surfaces, and the four third corner portions and the four first corner portions are arranged opposite to each other.

11. A household appliance, characterized in that: The transformer includes any one of claims 1 to 10.

Images