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 leakage magnetic sheet, and the core includes the upper yoke of head -to -tail connection, first side yoke, lower yoke and second side yoke, and the core still includes center column. Through the design of the both sides lateral wall of center column is respectively to the direction of first side yoke and second side yoke convex, and sets recessed structure in the lateral wall of first side yoke and second side yoke correspondingly, make the cross section shape of center column be approximately close to oval, and the oval profile perimeter is reduced compared to traditional rectangular cross section, thereby when satisfying same number of turns requirement, reduce the total amount of copper wire required for winding, directly reduce raw material cost. The reduction of winding total length also reduced its own resistance, effectively reduce the copper loss of transformer in the operation process, improve energy conversion efficiency and reduce the working temperature rise.

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] In related technologies, EI-type transformers used in microwave ovens typically have a core composed of a central post and side posts with rectangular cross-sections, with the windings wound on the central post. While the central post is usually rectangular in cross-section, its longer perimeter for the same cross-sectional area necessitates the use of more copper or aluminum wire for winding. This not only increases raw material costs but also leads to higher losses due to increased wire resistance, thereby reducing transformer operating efficiency and exacerbating temperature rise issues. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a transformer that can reduce the number of windings used and reduce manufacturing costs.

[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. A primary winding is fitted onto the central post; The secondary winding is sleeved on the central post and is spaced apart from the primary winding in the direction from the upper yoke toward the lower yoke; A magnetic leakage sheet is disposed between the primary winding and the secondary winding, and is spaced apart from the primary winding and the secondary winding; Wherein, the sidewall of the central column facing the first yoke protrudes towards the first yoke, the sidewall of the first yoke facing the central column is recessed in a direction away from the central column, the sidewall of the central column facing the second yoke protrudes towards the second yoke, and the sidewall of the second yoke facing the central column is recessed in a direction away from the central column.

[0006] The transformer according to the embodiments of the present invention has at least the following beneficial effects: By designing the two sidewalls of the center column to protrude towards the first and second yokes respectively, and correspondingly providing recessed structures on the sidewalls of the first and second yokes, the cross-sectional shape of the center column is made approximately elliptical. Since the winding is fitted onto the center column, its shape is also approximately elliptical, thus reducing the average length of each turn. This reduces the total amount of winding required to meet the same number of turns requirement, directly lowering raw material costs. The reduced total winding length also lowers its resistance, effectively reducing transformer losses during operation, thereby improving energy conversion efficiency and reducing operating temperature rise, thus improving the overall heat dissipation performance of the transformer.

[0007] According to some embodiments of the present invention, the first side yoke and the second side yoke are spaced apart along a first direction, and the upper yoke, the first side yoke, the central column and the lower yoke form a through hole, and the through hole penetrates both sides of the core along a second direction, the second direction being perpendicular to the first direction; The central column includes a first central step block and multiple first side step blocks. The multiple first side step blocks are connected sequentially along the second direction to form a first step group. There are two first step groups, which are respectively connected to the two sides of the first central step block along the second direction. Along the direction away from the first central step block, the length of the multiple first side step blocks along the first direction decreases sequentially.

[0008] According to some embodiments of the present invention, the minimum thickness of each of the first side step blocks along the second direction is equal, or At least some of the first side step blocks have unequal minimum thicknesses along the second direction.

[0009] According to some embodiments of the present invention, the first side yoke includes a second central step block and a plurality of second side step blocks. The plurality of second side step blocks are sequentially connected along the second direction to form a second step group. There are two second step groups, which are respectively connected to the two sides of the second central step block along the second direction. Along the direction away from the second central step block, the length of the plurality of second side step blocks increases sequentially along the first direction. The second central step block and the first central step block are arranged opposite to each other along the first direction. The second step group and the first step group are arranged opposite to each other along the first direction.

[0010] According to some embodiments of the present invention, the number of the first side step blocks and the number of the second side step blocks are the same and are arranged opposite to each other along the first direction, and the shortest distance between each oppositely arranged first side step block and second side step block along the first direction is the same.

[0011] According to some embodiments of the present invention, the second side yoke includes a third central step block and a plurality of third side step blocks. The plurality of third side step blocks are sequentially connected along the second direction to form a third step group. There are two third step groups, which are respectively connected to the two sides of the third central step block along the second direction. Along the direction away from the third central step block, the length of the plurality of third side step blocks increases sequentially along the first direction. The third central step block and the first central step block are arranged opposite to each other along the first direction. The third step group and the first step group are arranged opposite to each other along the first direction.

[0012] According to some embodiments of the present invention, the number of the first side step blocks and the number of the third side step blocks are the same and are arranged opposite to each other along the first direction, and the shortest distance between each oppositely arranged first side step block and third side step block along the first direction is the same.

[0013] According to some embodiments of the present invention, the first side yoke and the second side yoke are spaced apart along a first direction, and the iron core is symmetrically arranged along the first direction.

[0014] According to some embodiments of the present invention, the primary winding is constructed as an elliptical ring in cross-section along the axis perpendicular to the primary winding, and / or the secondary winding is constructed as an elliptical ring in cross-section along the axis perpendicular to the secondary winding.

[0015] According to some embodiments of the present invention, the primary winding is constructed as a polygonal ring structure in cross-section along the axial direction perpendicular to the primary winding, and / or the secondary winding is constructed as a polygonal ring structure in cross-section along the axial direction perpendicular to the secondary winding.

[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 designs the two sidewalls of the center column to protrude towards the first and second yokes respectively, and provides corresponding recessed structures on the sidewalls of the first and second yokes, making the cross-sectional shape of the center column approximately elliptical, thus reducing its perimeter compared to a traditional rectangular cross-section. Since the windings are fitted onto the center column, the shortened perimeter of the center column reduces the average length of each winding turn, thereby reducing the total amount of copper wire required for the windings while meeting the same number of turns requirement, directly lowering raw material costs. The reduced total winding length also lowers its own resistance, effectively reducing copper losses during transformer operation, thereby improving energy conversion efficiency and reducing operating temperature rise, thus improving the overall heat dissipation performance of the transformer.

[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 the transformer according to the first embodiment of this utility model; Figure 2 This is a front view of the transformer according to the first embodiment of this utility model; Figure 3 This is a schematic diagram of the hidden portion structure of the transformer according to the first embodiment of this utility model; Figure 4 This is a schematic diagram of the hidden core structure according to one embodiment of the present invention; Figure 5 This is a top view of the hidden core structure according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the transformer structure according to the second embodiment of this utility model; Figure 7 This is a schematic diagram of the hidden portion of the transformer structure according to the second embodiment of this utility model.

[0020] Figure label: Transformer 1000; Core 100; Upper yoke 110; First side yoke 120; Second central stepped block 121; Second side stepped block 122; Second stepped group 123; Lower yoke 130; Second side yoke 140; Third central stepped block 141; Third side stepped block 142; Third stepped group 143; Central column 150; First central stepped block 151; First side stepped block 152; First stepped group 153; Through hole 160; 200 for one winding; Secondary winding 300; High voltage winding 310; 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] Reference Figure 1 , Figure 2 and Figure 3As shown, the transformer 1000 of one embodiment of this utility model can be used in household appliances such as microwave ovens, household disinfection cabinets, dish sterilizers, air purifiers, and water purifiers. The transformer 1000 of this utility model embodiment includes an iron core 100, a primary winding 200, a secondary winding 300, and a magnetic leakage sheet 400. The core 100 includes 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 the two ends of the center post 150 are connected to the upper yoke 110 and the lower yoke 130, respectively. The primary winding 200 is sleeved on the center post 150. The secondary winding 300 is sleeved on the center post 150 and is spaced apart from the primary winding 200 in the direction from the upper yoke 110 toward the lower yoke 130. The leakage magnetic sheet 400 is located between the primary winding 200 and the secondary winding 300 and is spaced apart from the primary winding 200 and the secondary winding 300.

[0026] For example, the transformer 1000 in this embodiment is a leakage inductance high-voltage transformer 1000 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.

[0027] The leakage magnetic strip 400 can be a stack of silicon steel sheets, and it is the core component for achieving the "leakage inductance" function. The leakage magnetic strip 400 consists of a stack of 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.

[0028] Because magnetrons are easily affected by current magnitude, 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 characteristics 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, thereby limiting the current to a safe range, thus serving as a current limiter. Simultaneously, when the mains voltage fluctuates, because the iron 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.

[0029] In related technologies, the core of an EI-type transformer used in microwave ovens typically consists of a central post and side posts with a rectangular cross-section, with the winding wound on the central post. The rectangular cross-section results in a longer perimeter for the same cross-sectional area, requiring more copper wire for the winding, increasing raw material costs. Increased wire resistance also leads to higher copper losses, reducing operating efficiency and exacerbating temperature rise issues. In microwave oven applications requiring high energy efficiency, traditional structures struggle to balance the trade-off between material costs and energy loss.

[0030] To reduce the amount of windings used and lower production costs, refer to Figure 3 As shown in the embodiment of this utility model, the sidewall of the central column 150 facing the first yoke 120 protrudes towards the first yoke 120, the sidewall of the first yoke 120 facing the central column 150 is recessed in a direction away from the central column 150, the sidewall of the central column 150 facing the second yoke 140 protrudes towards the second yoke 140, and the sidewall of the second yoke 140 facing the central column 150 is recessed in a direction away from the central column 150.

[0031] The central column 150 of the core 100 and the corresponding first yoke 120 and second yoke adopt a complementary convex-concave fit. Therefore, the sidewall of the central column 150 expands outward to form a protrusion, and the sidewall of the yoke contracts inward to form a depression. A stepped edge or an elliptical edge can be achieved by a layered lamination process.

[0032] For example, the central column 150 cross-section simulates an approximately circular contour through a multi-level stepped structure. The area protruding corresponds to the area recessed in other parts, thus effectively shortening the circumference of the winding wrapping path while maintaining a constant total cross-sectional area. The side yoke recess design provides fitting space for the stepped cross-section, ensuring minimal magnetic reluctance when the magnetic circuit is closed. The leakage magnetic sheet 400 forms a magnetic shunt between the two windings, maintaining the necessary leakage inductance value while preventing stray magnetic fields from interfering with winding operation. The winding spacing and the leakage magnetic sheet 400 work together to optimize electromagnetic coupling efficiency.

[0033] The above technical solutions effectively reduce the amount of winding conductors used, minimizing resistance loss while ensuring magnetic flux transmission capacity. The feasibility of fabricating a stepped cross-section is superior to that of an ideal circle, balancing manufacturing costs and performance optimization. The improved magnetic circuit structure achieves dual control over energy loss and material consumption, making it suitable for electrical equipment with stringent energy efficiency requirements.

[0034] Reference Figure 4 and Figure 5 As shown in the embodiment of this utility model, the first side yoke 120 and the second side yoke 140 are spaced apart along the first direction. The upper yoke 110, the first side yoke 120, the central post 150, and the lower yoke 130 enclose a through hole 160. The through hole 160 penetrates both sides of the core 100 along the second direction, which is perpendicular to the first direction. The central post 150 includes a first central step block 151 and multiple first side step blocks 152. The multiple first side step blocks 152 are sequentially connected along the second direction to form a first step group 153. The first step group 153 has two members and is respectively connected to both sides of the first central step block 151 along the second direction. Along the direction away from the first central step block 151, the length of the multiple first side step blocks 152 along the first direction decreases sequentially, for example... Figure 5 As shown, the lengths of two adjacent first side steps are d1 and d2, respectively, where d2 is less than d1. It should be noted that, for ease of distinction between the first central step block 151 and the first side step block 152, Figure 5 The text uses dashed lines to divide the text.

[0035] The first central stepped block 151 refers to the core structure located in the middle of the second direction in the central column 150, which can be implemented by a combination of rectangular or approximately rectangular laminates. The first side stepped block 152 refers to the stepped laminates distributed on both sides of the first central stepped block 151 along the second direction, which can be implemented by stacking laminates with progressively narrower layers, thereby reducing the circumference of the winding by the stepped distribution.

[0036] For example, the core 100, through the spaced arrangement of the first side yoke 120 and the second side yoke 140 in the first direction, forms a closed magnetic circuit around the central column 150. The through-hole 160 formed by the upper yoke 110, the first side yoke 120, the central column 150, and the lower yoke 130 extends through both sides of the core 100 in the second direction, giving the core 100 an open structure in the second direction. This facilitates winding. The central column 150 consists of a first central stepped block 151 and two first stepped groups 153 on both sides. Multiple first side stepped blocks 152 in the first stepped group 153 are connected sequentially in the second direction, and the length of each first side stepped block 152 decreases progressively in the first direction away from the first central stepped block 151. Thus, the overall cross-section of the central column 150 approximates a circle or ellipse through a stepped structure, reducing the required circumference of the winding while maintaining the effective cross-sectional area.

[0037] This embodiment uses a stepped lamination distribution to make the cross-sectional shape of the central column 150 closer to an ellipse or circle, which significantly shortens the circumference of the winding under the same cross-sectional area, thereby reducing the amount of copper wire used and resistance loss.

[0038] Reference Figure 5 As shown in the embodiments of this utility model, the minimum thickness of each first side step block 152 along the second direction is equal. For example, the thicknesses of two adjacent first side step blocks 152 are b1 and b2, respectively, where b1 equals b2. Alternatively, at least some of the first side step blocks 152 have unequal minimum thicknesses along the second direction. For example, the thicknesses of two adjacent first side step blocks 152 are b1 and b2, respectively, where b1 and b2 are not equal.

[0039] The minimum thickness of the first side step block 152 refers to the minimum dimension of the component in the second direction. Equal minimum thickness means that the minimum dimension of all first side step blocks 152 in the second direction is consistent, for example, by using silicon steel sheets of uniform specifications to be stacked. At least partially unequal minimum thickness means that the minimum dimensions of some first side step blocks 152 are different, for example, by combining silicon steel sheets of different thicknesses to achieve the step transition.

[0040] For example, the central column 150 consists of a first central stepped block 151 and first side stepped blocks 152 on both sides. When the minimum thickness of all the first side stepped blocks 152 is equal, the magnetic circuit forms a uniform stepped transition in the second direction, which helps to reduce local magnetic reluctance differences. When the minimum thickness of some stepped blocks is different, the magnetic flux density distribution can be adjusted in specific areas. For example, a thicker stepped block can be used near the connection between the central column 150 and the yoke to enhance structural strength. By selecting the uniformity or difference in the thickness of the stepped blocks, the uniformity of the magnetic circuit and the structural stability can be flexibly balanced while keeping the total cross-sectional area constant.

[0041] Through the above technical solution, this embodiment can flexibly select the stepped block thickness configuration according to actual working conditions, reducing winding copper loss and improving the structural reliability of the core 100 while maintaining the total magnetic flux. When using uniform thickness, the processing flow can be simplified and the types of material specifications can be reduced; when using differential thickness, the magnetic circuit performance in high magnetic flux density areas can be specifically improved, avoiding local overheating or magnetic saturation.

[0042] Reference Figure 5 As shown in the embodiment of this utility model, the first side yoke 120 includes a second central step block 121 and a plurality of second side step blocks 122. The plurality of second side step blocks 122 are connected sequentially along the second direction to form a second step group 123. There are two second step groups 123, which are respectively connected to the two sides of the second central step block 121 along the second direction. Along the direction away from the second central step block 121, the length of the plurality of second side step blocks 122 increases sequentially along the first direction. The second central step block 121 and the first central step block 151 are arranged opposite each other along the first direction, and the second step group 123 and the first step group 153 are arranged opposite each other along the first direction.

[0043] The second central step block 121 refers to the main structure located in the middle of the first side yoke 120. The second side step block 122 refers to the stacked structure distributed on both sides of the second central step block 121, which can be achieved by arranging silicon steel sheets with decreasing thickness in a stepped manner. The design of its length increasing away from the center can form a magnetic circuit interface complementary to the stepped structure of the central column 150. The second step group 123 refers to the combined structure formed by stacking multiple second side step blocks 122 along the second direction. It can be achieved by symmetrically distributing stepped stacked sheets on both sides of the second central step block 121, and the gradual magnetic flux distribution area is formed by the change of step width.

[0044] For example, the second central step block 121 of the first side yoke 120 and the first central step block 151 of the central column 150 are arranged opposite each other along a first direction, and their step groups form complementary stepped contact surfaces. The width of the second side step block 122 increases in the direction away from the second central step block 121, forming an alternating fit with the decreasing width trend of the side step blocks of the central column 150. This structure optimizes the magnetic circuit contact area between the first side yoke 120 and the central column 150, resulting in a more uniform distribution of magnetic lines of force, thereby reducing magnetic resistance and leakage flux. The relative arrangement between the step groups further ensures a smooth transition when the magnetic flux forms a closed loop inside the core 100, avoiding local magnetic saturation.

[0045] This embodiment employs a stepped structure design to create a multi-level transition at the contact surface between the side yoke and the central column 150, effectively dispersing areas of concentrated magnetic flux density. Simultaneously, the increasing width of the stepped blocks on the side of the side yoke complements the decreasing width of the stepped blocks on the side of the central column 150. This design further shortens the required copper wire length for the winding, reducing wire resistance while maintaining a constant magnetic flux, thereby reducing copper losses during transformer 1000 operation and improving energy conversion efficiency. Furthermore, the symmetrical arrangement of the stepped structure simplifies the manufacturing process of the core 100, facilitating precision control during mass production.

[0046] Reference Figure 5 As shown in the embodiment of this utility model, the number of first side step blocks 152 and the number of second side step blocks 122 are the same and are arranged opposite to each other along the first direction. The shortest distance along the first direction between each oppositely arranged first side step block 152 and second side step block 122 is the same.

[0047] The arrangement of the two sets of stepped blocks in a mirror-symmetrical manner along the first direction can be achieved by using a die positioning device to ensure precise alignment during lamination assembly. The requirement of identical shortest distances means maintaining a constant gap between adjacent stepped blocks, which can be achieved by controlling the chamfer angle of the stepped block edges and the thickness of the laminated sheets.

[0048] For example, when the first side stepped block 152 and the second side stepped block 122 are arranged symmetrically, the magnetic flux path between the central column 150 and the side yoke is optimized to a uniform distribution. The corresponding positions of each stepped block maintain the same spacing, allowing the magnetic lines of force to smoothly transition in the stepped transition area. This symmetrical layout maintains a constant cross-sectional area of ​​the core 100 and reduces local magnetic reluctance through geometric matching of the stepped edges. During winding assembly, the equidistant gaps between the stepped blocks provide standardized installation space for the insulation material, facilitating automated production.

[0049] Through the above technical solutions, this embodiment effectively reduces hysteresis loss at the core 100 joint and reduces eddy current loss in the winding conductors under non-uniform magnetic fields. The symmetrical arrangement of the stepped structure makes the leakage flux distribution more uniform in the winding region, thereby improving energy transmission efficiency. The equidistant gap design provides a basis for standardized installation of the insulation system, which is beneficial to improving product consistency and production yield.

[0050] Reference Figure 5 As shown in the embodiment of this utility model, the second side yoke 140 includes a third central step block 141 and a plurality of third side step blocks 142. The plurality of third side step blocks 142 are connected sequentially along the second direction to form a third step group 143. There are two third step groups 143, which are respectively connected to the two sides of the third central step block 141 along the second direction. Along the direction away from the third central step block 141, the length of the plurality of third side step blocks 142 increases sequentially along the first direction. The third central step block 141 and the first central step block 151 are arranged opposite to each other along the first direction, and the third step group 143 and the first step group 153 are arranged opposite to each other along the first direction.

[0051] The third central step block 141 refers to the main structure extending along the second direction in the second side yoke 140, which can be formed by splicing stacked silicon steel sheets and is symmetrically arranged with the first central step block 151 along the first direction. The third side step block 142 refers to the step-like structure distributed on both sides of the third central step block 141, which can be composed of silicon steel sheet groups with progressively decreasing widths. By changing the width in a step-like manner, a magnetic circuit branch symmetrical to the first step group 153 is formed, thereby optimizing the magnetic flux distribution.

[0052] For example, the third central step block 141 of the second side yoke 140 and the first central step block 151 of the central column 150 are arranged symmetrically along a first direction. The third side step blocks 142 on both sides gradually expand their width with reference to a second direction, forming a stepped structure that is mirror-symmetrical to the first step group 153. The width of the third side step block 142 gradually increases outward from the third central step block 141, so that the gap between the second side yoke 140 and the central column 150 forms a stepped transition region. This structure makes the magnetic circuit distribution of the second side yoke 140 match the stepped cross-section of the central column 150. While maintaining the total cross-sectional area unchanged, the perimeter of the winding-enclosed area is shortened by the stepped edges, while maintaining the uniformity of magnetic flux density.

[0053] Through the above technical solution, this embodiment enables a symmetrical, stepped coupling of the magnetic circuit between the second yoke 140 and the central column 150. While ensuring magnetic flux transmission efficiency, it significantly reduces the wire length required for the primary winding 200 and the secondary winding 300, thereby reducing material costs and energy loss during operation. This structure is particularly suitable for transformer 1000 applications where strict control of winding volume and temperature rise is required.

[0054] Reference Figure 5 As shown in the embodiment of this utility model, the number of first side step blocks 152 and the number of third side step blocks 142 are the same and they are arranged opposite each other along the first direction. The shortest distance along the first direction between each oppositely arranged first side step block 152 and third side step block 142 is the same. The same shortest distance means that the gap between the oppositely arranged step blocks along the first direction is kept uniform, which can be achieved by adjusting the width and position of the step blocks, so as to ensure that the magnetic flux is uniformly distributed inside the iron core 100 and reduce magnetic leakage.

[0055] For example, the first side stepped blocks 152 on both sides of the central column 150 and the third side stepped blocks 142 on both sides of the second yoke 140 are arranged in equal numbers and symmetrically to form corresponding stepped groups. The gap between each stepped block remains the same along the first direction, so that the transmission path of magnetic flux between the central column 150 and the yoke is symmetrical and uniform. As a result, the overall magnetic reluctance of the core 100 is reduced, and the stepped structure shortens the winding circumference of the primary winding 200 and the secondary winding 300, thereby reducing the amount of copper wire used and resistance loss.

[0056] Reference Figure 5 As shown in the embodiment of this utility model, the first yoke 120 and the second yoke 140 are spaced apart along a first direction, and the core 100 is symmetrically arranged along the first direction. The first yoke 120 and the second yoke 140 of the core 100 are arranged on both sides of the central column 150, maintaining an equidistant distance along the horizontal direction. Simultaneously, the spatial arrangement of the entire core 100 and windings is symmetrically distributed with reference to the horizontal axis passing through the central column 150. Thus, the magnetic flux forms a symmetrical loop inside the core 100, and the stepped contact surfaces between the yokes and the central column 150 exhibit a mirror-image correspondence on both sides of the axis of symmetry. This symmetrical structure ensures that the winding paths of the primary winding 200 and the secondary winding 300 maintain the same length on both sides of the axis, thereby achieving uniform magnetic field distribution.

[0057] Through the above technical solution, this embodiment effectively reduces the amount of copper wire used in the winding, reduces resistance loss caused by excessive wire length, and at the same time, the symmetrical magnetic circuit design suppresses the uneven distribution of leakage flux, thereby improving energy conversion efficiency and reducing operating temperature rise.

[0058] Reference Figure 3As shown, in the embodiment of this utility model, the primary winding 200 of the transformer 1000 has a polygonal ring structure in cross-section along the axis perpendicular to the primary winding 200, and the secondary winding 300 has a polygonal ring structure in cross-section along the axis perpendicular to the secondary winding 300.

[0059] The polygonal ring structure refers to a closed shape formed by connecting at least three straight line segments end to end along the outer contour of the winding cross-section. This can be achieved using hexagonal, octagonal, or non-equilateral polygonal structures. The number of sides of the polygon can be adjusted according to the winding installation space and winding process. For example, it can be formed by stacking stamped metal sheets or by constraining the wire direction using a winding die to form a regular polygon. This structure replaces curved sides with straight sides, shortening the outer perimeter of the winding while maintaining the effective cross-sectional area, thereby reducing the length of wire required for winding.

[0060] For example, when the cross-sections of the primary winding 200 and the secondary winding 300 adopt a polygonal ring structure, the winding space on the center post 150 of the core 100 is divided into multiple planar regions by straight sides. For instance, an octagonal winding can be enclosed by eight straight sides to form an approximately elliptical cross-section with a shorter perimeter. The winding wires are arranged parallel to the polygonal sides, with adjacent sides transitioning through bends. Chamfers or rounded edges can be used at the bends to avoid local stress concentration. Since the perimeter of the polygon is smaller than that of a circle or ellipse of the same area, the amount of copper wire used in the winding is reduced, and the reduced wire resistance leads to lower copper losses.

[0061] Reference Figure 6 and Figure 7 As shown in the embodiment of this utility model, the primary winding 200 of the transformer 1000 has an elliptical ring cross-section along the axis perpendicular to the primary winding 200, and the secondary winding 300 has an elliptical ring cross-section along the axis perpendicular to the secondary winding 300.

[0062] Among them, the elliptical ring refers to a winding whose cross-sectional outline has an elliptical closed shape. It can be formed by continuously bending copper strips or wires to form a closed ring structure. The ratio of its major axis to minor axis can be adapted according to the stepped cross-sectional shape of the center column 150 of the iron core 100. By optimizing the geometry of the winding cross-section, the circumference of the winding can be shortened under the same cross-sectional area, thereby reducing the amount of copper wire used and resistance loss.

[0063] For example, when the cross-section of the primary winding 200 or the secondary winding 300 is elliptical, its perimeter is shorter than that of a traditional rectangular cross-section, reducing the length of copper wire required for winding within the same cross-sectional area. This optimization directly reduces the amount of copper wire used and the winding resistance, thereby reducing copper losses.

[0064] This utility model discloses a household appliance, 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, using the transformer 1000 described in the above embodiment, designs the two sidewalls of the central column 150 to protrude towards the first yoke 120 and the second yoke 140 respectively, and provides corresponding recessed structures on the sidewalls of the first yoke 120 and the second yoke 140. This makes the cross-sectional shape of the central column 150 approximately elliptical, reducing its perimeter compared to a traditional rectangular cross-section. Since the windings are fitted onto the central column 150, the shortened perimeter of the central column 150 reduces the average length of each winding turn, thereby reducing the total amount of copper wire required for the windings while meeting the same number of turns requirement, directly reducing raw material costs. The reduced total winding length also lowers its resistance, effectively reducing copper losses during transformer 1000 operation, thereby improving energy conversion efficiency and reducing operating temperature rise, thus improving the overall heat dissipation performance of transformer 1000.

[0065] 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.

[0066] 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. A primary winding is fitted onto the central post; The secondary winding is sleeved on the central post and is spaced apart from the primary winding in the direction from the upper yoke toward the lower yoke; A magnetic leakage sheet is disposed between the primary winding and the secondary winding, and is spaced apart from the primary winding and the secondary winding; Wherein, the sidewall of the central column facing the first yoke protrudes towards the first yoke, the sidewall of the first yoke facing the central column is recessed in a direction away from the central column, the sidewall of the central column facing the second yoke protrudes towards the second yoke, and the sidewall of the second yoke facing the central column is recessed in a direction away from the central column.

2. The transformer according to claim 1, characterized in that: The first side yoke and the second side yoke are spaced apart along a first direction, and the upper yoke, the first side yoke, the central column and the lower yoke form a through hole. The through hole extends through both sides of the core along a second direction, which is perpendicular to the first direction. The central column includes a first central step block and multiple first side step blocks. The multiple first side step blocks are connected sequentially along the second direction to form a first step group. There are two first step groups, which are respectively connected to the two sides of the first central step block along the second direction. Along the direction away from the first central step block, the length of the multiple first side step blocks along the first direction decreases sequentially.

3. The transformer according to claim 2, characterized in that: The minimum thickness of each of the first side step blocks along the second direction is equal, or At least some of the first side step blocks have unequal minimum thicknesses along the second direction.

4. The transformer according to claim 2, characterized in that: The first side yoke includes a second central step block and multiple second side step blocks. The multiple second side step blocks are connected sequentially along the second direction to form a second step group. There are two second step groups, which are respectively connected to the two sides of the second central step block along the second direction. Along the direction away from the second central step block, the length of the multiple second side step blocks increases sequentially along the first direction. The second central step block and the first central step block are arranged opposite each other along the first direction. The second step group and the first step group are arranged opposite each other along the first direction.

5. The transformer according to claim 4, characterized in that: The number of the first side step blocks and the number of the second side step blocks are the same and they are arranged opposite each other along the first direction. The shortest distance along the first direction between each of the oppositely arranged first side step blocks and second side step blocks is the same.

6. The transformer according to claim 2, characterized in that: The second side yoke includes a third central step block and multiple third side step blocks. The multiple third side step blocks are connected sequentially along the second direction to form a third step group. There are two third step groups, which are respectively connected to the two sides of the third central step block along the second direction. Along the direction away from the third central step block, the length of the multiple third side step blocks increases sequentially along the first direction. The third central step block and the first central step block are arranged opposite each other along the first direction. The third step group and the first step group are arranged opposite each other along the first direction.

7. The transformer according to claim 6, characterized in that: The number of the first side step blocks and the number of the third side step blocks are the same and they are arranged opposite each other along the first direction. The shortest distance along the first direction between each of the oppositely arranged first side step blocks and third side step blocks is the same.

8. The transformer according to any one of claims 1 to 7, characterized in that: The first side yoke and the second side yoke are spaced apart along the first direction, and the iron core is symmetrically arranged along the first direction.

9. The transformer according to claim 1, characterized in that: The primary winding is constructed as an elliptical ring in cross-section along the axis perpendicular to the primary winding, and / or the secondary winding is constructed as an elliptical ring in cross-section along the axis perpendicular to the secondary winding.

10. The transformer according to claim 1, characterized in that: The primary winding is constructed as a polygonal ring structure in cross-section along the axis perpendicular to the primary winding, and / or the secondary winding is constructed as a polygonal ring structure in cross-section along the axis perpendicular to the secondary winding.

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

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