JP7514995B1 - Transformers - Google Patents

Abstract

[Problem] To reduce resistance loss and iron loss. [Solution] An aspect of the present invention is a transformer that receives AC power from a power supply circuit, transforms the voltage and current by electromagnetic induction, and supplies AC power of the same frequency to a load circuit. The transformer has a primary winding connected to the power supply circuit. The transformer has a secondary winding connected to the load circuit. The transformer has a plurality of cylindrical iron cores that are linked to the primary winding and the secondary winding. The primary winding has a first winding wound around an annular bobbin. The secondary winding has a second winding provided inside the first winding, a third winding provided inside the second winding, a fourth winding provided outside the first winding, and a fifth winding provided outside the fourth winding. The second winding and the third winding are formed from different electric wires. The fourth winding and the fifth winding are formed from different electric wires. The width of the third winding is narrower than the width of the second winding. The width of the fifth winding is narrower than the width of the fourth winding. [Selected Figure] Figure 3

Description

The present invention relates to a transformer.

Transformers are used for the purpose of voltage transformation or current transformation.

The transformer described in Patent Document 1 includes a first coil. The transformer also includes a second coil arranged coaxially inside the first coil. The transformer also includes a third coil arranged coaxially outside the first coil. The transformer also includes a single bobbin that is arranged between the first coil and the second coil and between the first coil and the third coil and holds the first coil.

JP 2021-27104 A

It is preferable for resistive loss and iron loss, which reduce the efficiency of a transformer, to be as small as possible. Resistive loss is the power loss that occurs when current flows through a conductor. Iron loss is the loss that occurs when the magnetic flux passing through the iron core fluctuates periodically, and is the sum of hysteresis loss and eddy current loss.

In the transformer described in Patent Document 1, the first coil, second coil, third coil, and bobbin have rectangular cross-sectional shapes, and the iron core has a circular cross-sectional shape, so there is a large gap between the iron core and the coil, resulting in large resistance losses and iron losses.

An aspect of the present invention is a transformer that receives AC power from a power supply circuit, transforms the voltage and current by electromagnetic induction, and supplies AC power of the same frequency to a load circuit. The transformer includes a primary winding connected to the power supply circuit. The transformer includes a secondary winding connected to the load circuit. The transformer includes a plurality of cylindrical iron cores that are interlinked with the primary winding and the secondary winding. The primary winding has a first winding wound around an annular bobbin. The secondary winding has a second winding provided inside the first winding, a third winding provided inside the second winding, a fourth winding provided outside the first winding, and a fifth winding provided outside the fourth winding. The second winding and the third winding are formed from different electric wires. The fourth winding and the fifth winding are formed from different electric wires. The width of the third winding is narrower than the width of the second winding. The width of the fifth winding is narrower than the width of the fourth winding. A first end of the second winding is connected to a first end of the fifth winding. A first end of the third winding is connected to a first end of the fourth winding. A second end of the third winding is connected to a first voltage line of the load side circuit. A second end of the fifth winding is connected to a second voltage line of the load side circuit. A second end of the second winding and a second end of the fourth winding are connected to a neutral line of the load side circuit.

FIG. 1 is a perspective view showing an example of a transformer 100. FIG. 2 is a front view showing an example of a transformer 100 with a core 130 and a cover 140 removed. FIG. 3 is a diagram showing an example of a cross section taken along line A-A' in FIG. 2. 1 is a perspective view showing an example of one end portion of a second winding 122, a third winding 123, a fourth winding 124, and a fifth winding 125. FIG. 12 is a perspective view showing an example of the other ends of the second winding 122, the third winding 123, the fourth winding 124, and the fifth winding 125. FIG. FIG. 2 is a perspective view showing an example of a bobbin 150. 2 is a side view showing an example of a bobbin 150. FIG. FIG. 2 is a perspective view showing an example of a bobbin 150 with a first winding 111 wound thereon. 1 is a side view showing an example of a bobbin 150 with a first winding 111 wound thereon. FIG. FIG. 2 is a front view showing an example of a bobbin 150. 13 is a diagram showing an example of a protruding length of a support portion 152B. FIG. 13 is a front view showing an example of a guide portion 152C. FIG. 1 is a perspective view showing an example of a cover 140 enclosing a first winding 111, a second winding 122, a third winding 123, a fourth winding 124, a fifth winding 125 and a bobbin 150. FIG. FIG. 2 is a perspective view showing an example of a cover 140. 1 is a side view showing an example of a cover 140 when an end portion 141 is viewed from the front. 1 is a side view showing an example of a cover 140 when a hinge portion 142 is viewed from the front. FIG. 4 is a plan view showing an example of a cover 140. 1 is a perspective view showing an example of a cover 140 in a state where a pair of end portions 141 are closed. FIG. 1 is a plan view showing an example of a cover 140 in a state in which a pair of end portions 141 are closed. FIG. 1 is a front view showing an example of a cover 140 enclosing the first winding 111, the second winding 122, the third winding 123, the fourth winding 124, the fifth winding 125 and the bobbin 150. FIG. 21 is a diagram showing an example of a cross section taken along line B-B' in FIG. 20.

The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the invention described in the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention.

Figure 1 is a perspective view showing an example of a transformer 100.

The transformer 100 is a device that receives AC power from a power supply circuit, transforms the voltage and current through electromagnetic induction, and supplies AC power of the same frequency to a load circuit. The transformer 100 has a primary winding 110, a secondary winding 120, and two iron cores 130. For example, the transformer 100 is an oil-immersed transformer in which the primary winding 110, the secondary winding 120, and the iron cores 130 are immersed in transformer insulating oil, and the transformer 100 utilizes the electrical insulating and cooling effects of the transformer insulating oil.

The primary winding 110 is a winding that is connected to the power supply circuit.

The secondary winding 120 is the winding that is connected to the load side circuit.

The iron core 130 is cylindrical and is a component that is linked to the primary winding 110 and the secondary winding 120. In other words, the transformer 100 is a shell-type transformer in which multiple independent magnetic circuits are linked to one electric circuit. The iron core 130 is provided with the primary winding 110 and the secondary winding 120 sandwiched between the cover 140. The cover 140 is a cylindrical component that surrounds the primary winding 110 and the secondary winding 120.

Figure 2 is a front view showing an example of a transformer 100 with the core 130 and cover 140 removed.

The primary winding 110 has a first winding 111.

The first winding 111 is a winding wound around an annular bobbin 150. The bobbin 150 is a winding frame for winding an electric wire.

The secondary winding 120 has a second winding 122, a third winding 123, a fourth winding 124, and a fifth winding 125.

The second winding 122 is a winding provided inside the first winding 111. The second winding 122 is formed by winding a flat electric wire in the same direction as the width direction of the first winding 111 so that the surface of the electric wire is parallel to the height direction of the first winding 111. The second winding 122 is formed from an electric wire separate from the third winding 123.

The third winding 123 is a winding provided inside the second winding 122. The third winding 123 is formed by winding a flat electric wire in the same direction as the width direction of the first winding 111 so that the surface of the electric wire is parallel to the height direction of the first winding 111. The third winding 123 is formed from an electric wire separate from the second winding 122.

The fourth winding 124 is a winding provided on the outside of the first winding 111. The fourth winding 124 is formed by winding a flat electric wire in the same direction as the width direction of the first winding 111 so that the surface of the electric wire is parallel to the height direction of the first winding 111. The fourth winding 124 is formed from an electric wire different from that of the fifth winding 125.

The fifth winding 125 is a winding provided on the outside of the fourth winding 124. The fifth winding 125 is formed by winding a flat electric wire in the same direction as the width direction of the first winding 111 so that the surface of the electric wire is parallel to the height direction of the first winding 111. The fifth winding 125 is formed from an electric wire separate from the fourth winding 124.

Figure 3 is a diagram showing an example of a cross section taken along line A-A' in Figure 2. The width BW of the bobbin 150, the width WW2 of the second winding 122, the width WW3 of the third winding 123, the width WW4 of the fourth winding 124, and the width WW5 of the fifth winding 125 shown in Figure 3 are examples. The number of turns of the second winding 122, the number of turns of the third winding 123, the number of turns of the fourth winding 124, and the number of turns of the fifth winding 125 shown in Figure 3 are examples.

The width BW of the bobbin 150 is wider than the width WW2 of the second winding 122. The width BW of the bobbin 150 is also wider than the width WW3 of the third winding 123. The width BW of the bobbin 150 is also wider than the width WW4 of the fourth winding 124. The width BW of the bobbin 150 is also wider than the width WW5 of the fifth winding 125.

The width WW2 of the second winding 122 is narrower than the width BW of the bobbin 150. The width WW2 of the second winding 122 is wider than the width WW3 of the third winding 123. The width WW2 of the second winding 122 is the same as the width WW4 of the fourth winding 124. The width WW2 of the second winding 122 is wider than the width WW5 of the fifth winding 125.

The width WW3 of the third winding 123 is narrower than the width BW of the bobbin 150. The width WW3 of the third winding 123 is also narrower than the width WW2 of the second winding 122. The width WW3 of the third winding 123 is also narrower than the width WW4 of the fourth winding 124. The width WW3 of the third winding 123 is the same width as the width WW5 of the fifth winding 125.

The width WW4 of the fourth winding 124 is narrower than the width BW of the bobbin 150. The width WW4 of the fourth winding 124 is the same as the width WW2 of the second winding 122. The width WW4 of the fourth winding 124 is wider than the width WW3 of the third winding 123. The width WW4 of the fourth winding 124 is wider than the width WW5 of the fifth winding 125.

The width WW5 of the fifth winding 125 is narrower than the width BW of the bobbin 150. The width WW5 of the fifth winding 125 is also narrower than the width WW2 of the second winding 122. The width WW5 of the fifth winding 125 is the same as the width WW3 of the third winding. The width WW5 of the fifth winding 125 is also narrower than the width WW4 of the fourth winding 124.

In the width direction, the number of turns of the third winding 123 is less than the number of turns of the second winding 122. In the example shown in FIG. 3, the number of turns of the second winding 122 is "26". In the example shown in FIG. 3, the number of turns of the third winding 123 is "10".

In the width direction, the number of turns of the fifth winding 125 is less than the number of turns of the fourth winding 124. In the example shown in FIG. 3, the number of turns of the fourth winding 124 is "26". In the example shown in FIG. 3, the number of turns of the fifth winding 125 is "10".

In the width direction, the number of turns of the second winding 122 is the same as the number of turns of the fourth winding 124. In the example shown in FIG. 3, the number of turns of the second winding 122 and the number of turns of the fourth winding 124 are both 26.

In the width direction, the number of turns of the third winding 123 is the same as the number of turns of the fifth winding 125. In the example shown in FIG. 3, the number of turns of the third winding 123 and the number of turns of the fifth winding 125 are both "10."

The number of turns of the second winding 122 needs to be greater than the number of turns of the third winding 123 and the same as the number of turns of the fourth winding 124, and may be greater or less than 26.

The number of turns of the third winding 123 needs to be less than the number of turns of the second winding 122 and the same as the number of turns of the fifth winding 125, and may be less or more than "10".

The number of turns of the fourth winding 124 needs to be greater than the number of turns of the fifth winding 125 and the same as the number of turns of the second winding 122, and may be greater or less than 26.

The number of turns of the fifth winding 125 may be less than the number of turns of the fourth winding 124 and the same as the number of turns of the third winding 123, and may be more or less than "10".

Figure 4 is a perspective view showing an example of one end of the second winding 122, the third winding 123, the fourth winding 124, and the fifth winding 125. In order to clearly show one end of the second winding 122, the third winding 123, the fourth winding 124, and the fifth winding 125, Figure 4 does not show the first winding 111 and the bobbin 150.

The electric wire EW2A extending from the first end 122A of the second winding 122 is bent toward the front at the first end 122A. Similarly, the electric wire EW3A extending from the first end 123A of the third winding 123 is bent toward the front at the first end 123A. Similarly, the electric wire EW4A extending from the first end 124A of the fourth winding 124 is bent toward the front at the first end 124A. Similarly, the electric wire EW5A extending from the first end 125A of the fifth winding 125 is bent toward the front at the first end 125A.

The electric wires EW2A and EW5A are connected by the connecting member JE1. Similarly, the electric wires EW3A and EW4A are connected by the connecting member JE2.

Figure 5 is a perspective view showing an example of the other ends of the second winding 122, the third winding 123, the fourth winding 124, and the fifth winding 125. In order to clearly show the other ends of the second winding 122, the third winding 123, the fourth winding 124, and the fifth winding 125, Figure 5 does not show the first winding 111 and the bobbin 150.

The electric wire EW2B extending from the second end 122B of the second winding 122 is bent toward the rear side at the second end 122B. Similarly, the electric wire EW3B extending from the second end 123B of the third winding 123 is bent toward the rear side at the second end 123B. Similarly, the electric wire EW4B extending from the second end 124B of the fourth winding 124 is bent toward the rear side at the second end 124B. Similarly, the electric wire EW5B extending from the second end 125B of the fifth winding 125 is bent toward the rear side at the second end 125B.

The electric wire EW3B is connected to the connection terminal CT1. The connection terminal CT1 is connected to the first voltage line of the load side circuit.

The electric wire EW5B is connected to the connection terminal CT2. The connection terminal CT2 is connected to the second voltage line of the load side circuit.

Electric wire EW2B and electric wire EW4B are connected to connection terminal CT3. Connection terminal CT3 is connected to the neutral wire of the load side circuit.

As described above, the transformer 100 is a device that receives AC power from a power supply circuit, transforms the voltage and current by electromagnetic induction, and supplies AC power of the same frequency to a load circuit. The transformer 100 has a primary winding 110 connected to the power supply circuit. The transformer 100 also has a secondary winding 120 connected to the load circuit. The transformer 100 also has two cylindrical iron cores 130 that are interlinked with the primary winding 110 and the secondary winding 120. The primary winding 110 has a first winding 111 wound around an annular bobbin 150. The secondary winding 120 has a second winding 122 provided inside the first winding 111 and a third winding 123 provided inside the second winding 122. In addition, the secondary winding 120 has a fourth winding 124 provided outside the first winding 111 and a fifth winding 125 provided outside the fourth winding 124. The second winding 122 and the third winding 123 are formed of different electric wires. The fourth winding 124 and the fifth winding 125 are formed of different electric wires. The width WW3 of the third winding 123 is narrower than the width WW2 of the second winding 122. The width WW5 of the fifth winding 125 is narrower than the width WW4 of the fourth winding 124. With this configuration, the cross-sectional shape of each winding and the bobbin 150 of the transformer 100 follows the circular cross-sectional shape of the iron core 130, so that the gap between the iron core 130 and each winding is small, and resistance loss and iron loss can be suppressed.

In addition, the width WW3 of the third winding 123 and the width WW5 of the fifth winding 125 are narrower than the width BW of the bobbin 150. With this configuration, the cross-sectional shapes of the windings and bobbin 150 of the transformer 100 are more likely to conform to the circular cross-sectional shape of the iron core 130, making it possible to reduce the gap between the iron core 130 and each winding, and more efficiently suppressing resistance loss and iron loss.

In addition, the width WW2 of the second winding 122 and the width WW4 of the fourth winding 124 are narrower than the width BW of the bobbin 150. With this configuration, the cross-sectional shapes of the windings and bobbin 150 of the transformer 100 are more likely to conform to the circular cross-sectional shape of the iron core 130, making it possible to reduce the gap between the iron core 130 and each winding, and more efficiently suppressing resistance loss and iron loss.

The width WW2 of the second winding 122 is the same as the width WW4 of the fourth winding 124. The width WW3 of the third winding 123 is the same as the width WW5 of the fifth winding 125. With this configuration, the cross-sectional shapes of the windings and bobbin 150 of the transformer 100 are more likely to conform to the circular cross-sectional shape of the iron core 130, making it possible to reduce the gap between the iron core 130 and each winding, and more efficiently suppressing resistance loss and iron loss.

In addition, in the width direction, the number of turns of the third winding 123 is smaller than the number of turns of the second winding 122. In the width direction, the number of turns of the fifth winding 125 is smaller than the number of turns of the fourth winding 124. With this configuration, the cross-sectional shape of each winding and bobbin 150 of the transformer 100 is more likely to conform to the circular cross-sectional shape of the iron core 130, making it possible to reduce the gap between the iron core 130 and each winding, and more efficiently suppressing resistance loss and iron loss.

In addition, in the width direction, the number of turns of the second winding 122 is the same as the number of turns of the fourth winding 124. In the width direction, the number of turns of the third winding 123 is the same as the number of turns of the fifth winding 125. With this configuration, the cross-sectional shape of each winding and bobbin 150 of the transformer 100 is more likely to conform to the circular cross-sectional shape of the iron core 130, the gap between the iron core 130 and each winding can be made smaller, and resistance loss and iron loss can be suppressed more efficiently.

Furthermore, the first end 122A of the second winding 122 is connected to the first end 125A of the fifth winding 125. The first end 123A of the third winding 123 is connected to the first end 124A of the fourth winding 124. With this configuration, the secondary winding 120 of the transformer 100 is formed by two sets of windings that combine a wide winding and a narrow winding.

The second end 123B of the third winding 123 is connected to a first voltage line of the load side circuit. The second end 125B of the fifth winding 125 is connected to a second voltage line of the load side circuit. The second end 122B of the second winding 122 and the second end 124B of the fourth winding 124 are connected to the neutral line of the load side circuit. With this configuration, the transformer 100 can supply AC power to a single-phase three-wire load side circuit.

The second winding 122, the third winding 123, the fourth winding 124, and the fifth winding 125 are formed from flat electric wire. With this configuration, the transformer 100 can form the secondary coil without using a winding form for the secondary coil.

The primary winding 110, secondary winding 120, and iron core 130 are immersed in transformer insulating oil. With this configuration, the transformer 100 can utilize the insulating and cooling effects of the oil.

Figure 6 is a perspective view showing an example of the bobbin 150. Figure 7 is a side view showing an example of the bobbin 150. Figure 8 is a perspective view showing an example of the bobbin 150 with the first winding 111 wound thereon. Figure 9 is a side view showing an example of the bobbin 150 with the first winding 111 wound thereon.

The bobbin 150 has two flanges 151 and multiple partitions 152. In the example shown in Figs. 6 and 7, the bobbin 150 has five partitions 152. The number of partitions 152 shown in Figs. 6 and 7 is an example. There may be one or more partitions 152, and there may be more or less than five.

The flanges 151 are provided at both ends of the bobbin 150 in the width direction and are used to prevent the first winding 111 from slipping off the bobbin 150.

The partitions 152 are members that divide the outer periphery of the bobbin 150 into multiple winding regions WR. The outer periphery of the bobbin 150 is divided by the partitions 152 into winding regions WR, the number of which is one more than the number of partitions 152. In the example shown in FIG. 7, the outer periphery of the bobbin 150 is divided into six winding regions WR by five partitions 152. The first winding 111 is wound in the winding region WR on the outer periphery of the bobbin 150. That is, the partitions 152 divide the first winding 111 on the outer periphery of the bobbin 150.

The flange 151 has a plurality of protrusions 151A and a support portion 151B. In the example shown in Figs. 6 and 8, the flange 151 has 12 protrusions 151A. The number of protrusions 151A shown in Figs. 6 and 8 is an example. The flange 151 only needs to have a plurality of protrusions 151A, and may have fewer than 12 protrusions 151A or more than 12 protrusions 151A.

The partition 152 has multiple protrusions 152A and support parts 152B. In the example shown in Figures 6 and 8, the partition 152 is illustrated at an angle where some of the protrusions 152A are not visible, but has 12 protrusions 152A. The number of protrusions 152A shown in Figures 6 and 8 is an example. The partition 152 only needs to have multiple protrusions 152A, and may have fewer than 12 protrusions 152A or more than 12 protrusions 152A.

The protrusion 151A is a rod-shaped portion that protrudes outward from the flange portion 151. The multiple protrusions 151A are spaced apart from one another in the winding direction of the first winding 111. Similarly, the protrusion 152A is a rod-shaped portion that protrudes outward from the partition portion 152. The multiple protrusions 152A are spaced apart from one another in the winding direction of the first winding 111. The protrusions 152A shown in Figures 6 to 9 are located at a position that overlaps with the protrusion 151A in a front view. The tips of the protrusions 151A and 152A are located outside the outer circumferential end of the first winding 111.

Support portion 151B is a portion of flange portion 151 that supports protruding portion 151A. Support portion 151B extends in the winding direction of first winding 111 and protrudes from the outer periphery of bobbin 150. Similarly, support portion 152B is a portion of partition portion 152 that supports protruding portion 152A. Support portion 152B extends in the winding direction of first winding 111 and protrudes from the outer periphery of bobbin 150.

The first winding 111, which is separated by the partition 152, is formed from a single electric wire. The end of the winding of the first winding 111 wound in the winding region WR straddles the outside of the partition 152 and becomes the beginning of the winding of the first winding 111 wound in the adjacent winding region WR.

The flange portion 151 has two protective portions 151C. The protective portions 151C are portions that protect the beginning and end of the first winding 111. The two protective portions 151C are spaced apart from each other in the winding direction of the first winding 111.

The partition 152 includes a guide portion 152C. The guide portion 152C is a portion that guides the first winding 111 that straddles the outside of the partition 152. The guide portion 152C is fan-shaped when viewed from the front.

Figure 10 is a front view showing an example of a bobbin 150.

When viewed from the front, the bobbin 150 is a rectangular ring with rounded corners 150A.

In the example shown in FIG. 10, the protrusions 151A are provided at the corners 150A and the sides 150B in the front view of the bobbin 150. When the protrusions 151A are provided at the corners 150A and the sides 150B as in the example shown in FIG. 10, the number of the protrusions 151A provided at one corner 150A may be greater than the number of the protrusions 151A provided at one side 150B. In the example shown in FIG. 10, the number of the protrusions 151A provided at one corner 150A is two or three. In the example shown in FIG. 10, the number of the protrusions 151A provided at one side 150B is one. The number of the protrusions 151A provided at one corner 150A may be greater than the number of the protrusions 151A provided at one side 150B, and may be less than two or more than three. Furthermore, the number of protrusions 151A provided on one side 150B may be less than the number of protrusions 151A provided on one corner 150A, and may be two or more.

Similarly, the protrusions 152A are provided at the corners 150A and the sides 150B when viewed from the front of the bobbin 150. The number of protrusions 152A provided at one corner 150A is greater than the number of protrusions 152A provided at one side 150B. Although the protrusions 152A are shown at an angle where they are hidden by the protrusions 151A and cannot be seen, the number of protrusions 152A provided at one corner 150A shown in FIG. 10 is two or three. Although the protrusions 152A are shown at an angle where they are hidden by the protrusions 151A and cannot be seen, the number of protrusions 152A provided at one side 150B shown in FIG. 10 is one.

Figure 11 shows an example of the protruding length of the support portion 152B.

The protruding length of the support portion 152B is set to a length that satisfies the insulation distance when the creepage distance CD between the windings of the first winding 111 separated by the partition portion 152 is the shortest distance along the surface of the bobbin 150 between the first winding 111 on both sides of the partition portion 152 separated by the partition portion 152. The creepage distance CD of the bobbin 150 is a path along the surface of the winding region WR and the surface of the support portion 152B. The insulation distance is a distance that prevents the first winding 111 on both sides of the partition portion 152 separated by the partition portion 152 from shorting each other.

Figure 12 is a front view showing an example of guide section 152C.

The guide portion 152C has a notch portion N1 and an inclined portion S1.

The notch N1 is the portion where the wire of the first winding 111 that straddles the outside of the partition portion 152 in the guide portion 152C is placed.

The inclined portion S1 is a portion that guides the electric wire that is hung in the notch portion N1 in the guide portion 152C to the surface of the winding region WR at the outer periphery.

As described above, the primary winding 110 is wound around the outer periphery of the annular bobbin 150. The bobbin 150 has partitions 152 that divide the primary winding 110 in the width direction of the outer periphery. The partitions 152 have multiple protrusions 152A that protrude outward. The multiple protrusions 152A are spaced apart from each other in the winding direction of the primary winding 110. With this configuration, when the transformer 100 is used as an oil-filled transformer, air is less likely to remain between the primary winding 110 and the partitions 152 when a vacuum is drawn.

In addition, the tips of the protrusion 152A and the guide portion 152C are located outside the outer peripheral end of the primary winding 110. With this configuration, the transformer 100 can prevent the first winding 111 and the fourth winding 124 from coming into contact.

The bobbin 150 is a rectangular ring shape with rounded corners 150A. The protrusions 152A are provided at the corners 150A of the bobbin 150. With this configuration, the transformer 100 can prevent the first winding 111 from becoming unwound at the corners 150A of the bobbin 150.

The protrusion 152A is provided on the side portion 150B of the bobbin 150. With this configuration, the transformer 100 can prevent the first winding 111 from becoming unwound at the side portion 150B of the bobbin 150.

The number of protrusions 152A provided at one corner 150A is greater than the number of protrusions 152A provided at one side 150B. With this configuration, the transformer 100 can prevent the first winding 111 from becoming unwound, while also preventing air from remaining between the primary winding 110 and the partition 152 when used as an oil-filled transformer.

The partition 152 also includes a support 152B that supports the protruding portion 152A. The support 152B extends in the winding direction of the primary winding 110 and protrudes from the outer periphery. The protruding length of the support 152B is set to a length that satisfies the insulation distance when the creepage distance CD between the turns of the primary winding 110 separated by the partition 152. With this configuration, the transformer 100 can effectively prevent air from remaining between the primary winding 110 and the partition 152 by setting the protruding length of the support 152B to a length that satisfies the insulation distance when the creepage distance CD is set to a length that satisfies the insulation distance.

The primary winding 110 separated by the partition 152 is formed from a single electric wire. The partition 152 is provided with a guide portion 152C that guides the electric wire of the primary winding 110 that straddles the outside of the partition 152. With this configuration, the worker assembling the transformer 100 can guide the electric wire at the end of the winding of the primary winding 110 wound in the winding region WR as the electric wire that starts winding the primary winding 110 wound in the adjacent winding region WR.

The guide portion 152C also has a notch N1 for hanging the wire of the primary winding 110 that straddles the outside of the partition portion 152. With this configuration, the worker assembling the transformer 100 can apply tension to the primary winding 110 that straddles the outside of the partition portion 152.

The guide portion 152C also has an inclined portion S1 that guides the wire hung in the notch portion N1 to the surface of the outer periphery. With this configuration, the worker assembling the transformer 100 can start winding the primary winding 110, which is separated by the partition portion 152, from the surface of the outer periphery of the bobbin 150.

Figure 13 is a perspective view showing an example of the cover 140 enclosing the first winding 111, the second winding 122, the third winding 123, the fourth winding 124, the fifth winding 125, and the bobbin 150. Figure 14 is a perspective view showing an example of the cover 140. Figure 15 is a side view showing an example of the cover 140 when the end portion 141 is viewed from the front. Figure 16 is a side view showing an example of the cover 140 when the hinge portion 142 is viewed from the front.

The cover 140 is made of synthetic resin. The cover 140 has a pair of end portions 141 and a hinge portion 142.

The edge portions 141 are portions of the cover 140 that allow a portion of the cover 140 to be opened and closed while remaining integral. The pair of edge portions 141 are fixed to each other by snap-fitting. One edge portion 141 has a protruding portion 141A for the snap-fitting. The other edge portion 141 has a recessed portion 141B for the snap-fitting. The snap-fitting is an assembly method in which the protruding portion 141A is fitted and hooked into the recessed portion 141B using the elasticity of the material, thereby mechanically fixing the cover 140 in place.

The hinge portion 142 is a fulcrum when the pair of end portions 141 of the cover 140 open.

Figure 17 is a plan view showing an example of a cover 140.

The thickness of the hinge portion 142 is thinner than the thickness of other parts of the cover 140. In the example shown in FIG. 17, the hinge portion 142 is formed by reducing the thickness.

Figure 18 is a perspective view showing an example of a cover 140 with a pair of end edges 141 closed. Figure 19 is a plan view showing an example of a cover 140 with a pair of end edges 141 closed.

The hinge portion 142 is provided at a symmetrical position of the end edge portion 141 with respect to the axis AX of the cover 140 when the pair of end edge portions 141 are closed.

Figure 20 is a front view showing an example of the cover 140 enclosing the first winding 111, the second winding 122, the third winding 123, the fourth winding 124, the fifth winding 125, and the bobbin 150.

The bobbin 150 has a first restricting portion 153A and a second restricting portion 153B.

The first regulating portion 153A is a component that regulates the position of one end of the cover 140 in the axial direction. The first regulating portion 153A is provided on the front side and the rear side of the bobbin 150, respectively. The first regulating portion 153A on the front side and the first regulating portion 153A on the rear side are provided in symmetrical positions when viewed from the front. The cover 140 shown in FIG. 20 is regulated from moving upward in the vertical direction of the drawing by the first regulating portion 153A.

The second regulating portion 153B is a component that regulates the position of the other end of the cover 140 in the axial direction. The second regulating portion 153B is provided on the front side and the rear side of the bobbin 150, respectively. The front side second regulating portion 153B and the rear side second regulating portion 153B are provided in symmetrical positions when viewed from the front. The cover 140 shown in FIG. 20 is regulated from moving downward in the up-down direction of the drawing by the second regulating portion 153B.

The first restricting portion 153A and the second restricting portion 153B are provided at positions such that the distance from the first restricting portion 153A to the second restricting portion 153B is the same as or slightly longer than the axial length of the cover 140.

Figure 21 shows an example of a cross section taken along line B-B' in Figure 20.

The radial inner shape of the cover 140 follows the outer shape of the first winding 111, the second winding 122, the third winding 123, the fourth winding 124, the fifth winding 125, and the bobbin 150.

As described above, the iron core 130 is provided with the primary winding 110 and the secondary winding 120 sandwiching the cylindrical cover 140 that surrounds the primary winding 110 and the secondary winding 120. The cover 140 has a pair of end edges 141 that allow a portion of the cover to be opened or closed while remaining integral. With this configuration, the designer of the transformer 100 does not need to make design changes to the cover 140 even if the distance between the two covers 140 changes due to a design change.

The pair of end edges 141 are fixed to each other by a snap fit. This configuration makes it easier for the worker assembling the transformer 100 to attach the cover 140.

The cover 140 also includes a hinge portion 142 that serves as a fulcrum when the end portion 141 opens. With this configuration, the worker assembling the transformer 100 can open the cover 140 without applying excessive load to the cover 140.

The thickness of the hinge portion 142 is thinner than the thickness of other portions of the cover 140. This configuration prevents load from being applied to portions other than the hinge portion 142 when the cover 140 is unfolded.

The hinge portion 142 is formed by reducing the thickness of the cover 140. With this configuration, the cover 140 can form the hinge portion 142 without using metal.

The hinge portion 142 is provided at a symmetrical position of the end portion 141 with respect to the axis AX of the cover 140 when the pair of end portions 141 are closed. With this configuration, the end portions 141 of the cover 140 can be opened and closed smoothly.

The radial inner shape of the cover 140 is shaped to follow the outer shapes of the primary winding 110 and the secondary winding 120. With this configuration, when the cover 140 is attached so as to surround the primary winding 110 and the secondary winding 120, the cover 140 is prevented from rotating in the circumferential direction.

The cover 140 is also made of synthetic resin. With this configuration, the transformer 100 does not have an unintended magnetic circuit caused by the cover 140.

The bobbin 150 also includes a first restricting portion 153A that restricts the position of one end of the cover 140 in the axial direction. The bobbin 150 includes a second restricting portion 153B that restricts the position of the other end of the cover 140 in the axial direction. With this configuration, when the cover 140 is attached to surround the primary winding 110 and the secondary winding 120, the cover 140 is restricted from shifting in the axial direction.

Although the present invention has been described above using an embodiment, the technical scope of the present invention is not limited to the scope described in the embodiment. It will be clear to those skilled in the art that various modifications and improvements can be made to the embodiment. It is clear from the claims that forms incorporating such modifications or improvements can also be included in the technical scope of the present invention.

In the embodiment, the protrusion 152A is provided at a position overlapping the protrusion 151A in a front view. However, the multiple protrusions 152A only need to be spaced apart from one another in the winding direction of the first winding 111, and do not have to be provided at a position overlapping the protrusion 151A in a front view. For example, the multiple protrusions 152A may be provided at a position that does not overlap the protrusion 151A in a front view. Similarly, the protrusion 152A of a partition 152 may be provided at a position that does not overlap the protrusion 152A of another partition 152 in a front view.

In the embodiment, the rod-shaped protrusion 151A and the rod-shaped protrusion 152A are provided at the corner 150A and the side 150B. However, the protrusion 151A and the protrusion 152A provided at the corner 150A do not have to be rod-shaped. For example, the protrusion 151A and the protrusion 152A provided at the corner 150A may be fan-shaped when viewed from the front.

The hinge portion 142 in the embodiment is formed by reducing the thickness. However, the hinge portion 142 is not limited to being formed by reducing the thickness as long as it serves as a fulcrum when the pair of end portions 141 of the cover 140 open. For example, the hinge portion 142 may be a hinge made of resin.

100 transformer, 110 primary winding, 111 first winding, 120 secondary winding, 122 second winding, 123 third winding, 124 fourth winding, 125 fifth winding, 130 core, 140 cover, 141 edge portion, 141A convex portion, 141B concave portion, 142 hinge portion, 150 bobbin, 150A corner portion, 150B edge portion, 151 flange portion, 151A protruding portion, 151B supporting portion, 151C protective portion, 152 partition portion, 152A protruding portion, 152B supporting portion, 152C guide portion, 153A first restricting portion, 153B second restricting portion

Claims (10)

A transformer that receives AC power from a power supply circuit, transforms the voltage and current by electromagnetic induction, and supplies AC power of the same frequency to a load circuit,
A primary winding connected to a power supply circuit;
A secondary winding connected to a load circuit;
a plurality of cylindrical iron cores interlinked with the primary winding and the secondary winding,
The primary winding includes a first winding wound on an annular bobbin,
the secondary winding includes a second winding provided inside the first winding, a third winding provided inside the second winding, a fourth winding provided outside the first winding, and a fifth winding provided outside the fourth winding,
the second winding and the third winding are formed from different electric wires,
the fourth winding and the fifth winding are formed from different electric wires,
The width of the third winding is narrower than the width of the second winding,
The width of the fifth winding is narrower than the width of the fourth winding,
a first end of the second winding is connected to a first end of the fifth winding;
a first end of the third winding is connected to a first end of the fourth winding;
a second end of the third winding is connected to a first voltage line of a load side circuit;
a second end of the fifth winding is connected to a second voltage line of a load side circuit;
A transformer , wherein the second end of the second winding and the second end of the fourth winding are connected to a neutral line of a load side circuit . The transformer of claim 1, wherein the width of the third winding and the width of the fifth winding are narrower than the width of the bobbin. The transformer of claim 1, wherein the width of the second winding and the width of the fourth winding are narrower than the width of the bobbin. The width of the second winding is the same as the width of the fourth winding,
2. The transformer of claim 1, wherein the width of the third winding is the same as the width of the fifth winding. In the width direction, the number of turns of the third winding is smaller than the number of turns of the second winding,
2. The transformer according to claim 1, wherein the number of turns of the fifth winding is less than the number of turns of the fourth winding in the width direction. In the width direction, the number of turns of the second winding is the same as the number of turns of the fourth winding,
2. The transformer according to claim 1, wherein the number of turns of the third winding is the same as the number of turns of the fifth winding in the width direction. The transformer according to claim 1, wherein the second winding, the third winding, the fourth winding, and the fifth winding are formed from flat wires. The transformer of claim 1, wherein the primary winding, the secondary winding, and the iron core are immersed in transformer oil. a first end of the second winding is connected to a first end of the fifth winding on a front side of the bobbin;
a first end of the third winding is connected to a first end of the fourth winding on a front side of the bobbin;
a second end of the third winding connected to a first voltage line of a load side circuit on the back side of the bobbin;
a second end of the fifth winding connected to a second voltage line of a load side circuit on the back side of the bobbin;
2. The transformer according to claim 1, wherein the second end of the second winding and the second end of the fourth winding are connected to a neutral line of a load side circuit on a back side of the bobbin. 2. The transformer according to claim 1, wherein the primary winding and the secondary winding are arranged to be symmetrical about a diameter of the core in a plan view intersecting a cylindrical surface of the core.

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