JPH04251903A - Rectifier transformer - Google Patents

Abstract

PURPOSE:To make a middle yoke free in the shaft direction of a main leg for a rectifier transformer provided with the middle yoke. CONSTITUTION:A middle yoke 17 is connected with a main leg 16 by being aligned with the leg, and the middle yoke 17 is held in a middle ring through a cushion layer filled in the through hole of the middle ring. The middle yoke 17 is formed by a magnetic steel plate laminated in a direction 90 deg. from the laminating direction of the magnetic steel plate of the main leg 16. The middle yoke 17 and the main leg 16 are simultaneously sandwiched and bound by binding plates composed of plates longer than the whole length of the middle yoke 17 in the shaft direction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rectifier transformer for rectifying a secondary output to obtain a DC output.

0002

[Prior Art] A rectifier transformer is equipped with a triangular connected winding and a star connected winding as secondary windings in one transformer, and these are double bridge connected to obtain a rectified output. It is designed to provide an output closer to direct current as a phase rectifier. In the double three-phase bridge connection, it is necessary to match the output voltage of the triangular connection winding and the output voltage of the star connection winding as much as possible, but since the secondary winding is a high current winding, the number of turns is limited. Usually it's only about 3 to 20 turns. Therefore, if the primary winding is shared, a difference will occur in the output voltage between the triangular connected winding and the star connected winding. For example, in a combination of 12 turns of the triangular connected secondary winding and 7 turns of the star connected secondary winding, a voltage difference of 7×30.5 −12=0.12 turns occurs. In order to eliminate this drawback, the iron core is constructed using three yokes: an upper yoke, an intermediate yoke, and a lower end yoke, which magnetically connect the upper, middle, and lower ends of the main legs of the three-phase core. Configure. A triangular-connected secondary winding and its corresponding primary winding are wound around the main leg at the top of the intermediate yoke, and a star-shaped secondary winding and its corresponding primary winding are wound around the main leg at the bottom of the intermediate yoke. Wind the wire. This allows the intermediate yokes to be shared but each to function as a separate transformer, with the turns ratio of each being adjusted by the primary winding to match the secondary output voltages of the triangular and star connected windings. What is possible is shown in Japanese Patent Publication No. 1-29046.

FIG. 8 is a front view showing an example of the configuration of a conventional rectifier transformer core. This iron core has three main legs 1 formed by laminating silicon steel plates, an upper end yoke 2A and a lower end yoke 2C, which connect both ends of the main legs 1.
It is composed of an intermediate yoke 2B that connects the intermediate part of the main leg 1. The connection portions between the main landing gear 1 and each of the yokes 2A, 2B, and 2C are lap joints in which silicon steel plate ends are cut diagonally and joined so that each layer partially overlaps.

FIG. 9 is a sectional view showing an example of the main part configuration of a conventional rectifier transformer. A primary winding 3A and a secondary winding 3B winding the main leg 1 around the upper part of the intermediate yoke 2B shown in FIG.
Another winding group 4 consisting of a primary winding 4A and a secondary winding 4B around which the main leg 1 is wound is arranged below the intermediate yoke 2B. Insulating intermediate rings 5A and 5B are interposed between the primary windings 3A and 4A and between the secondary windings 3B and 4B, respectively. Press rings 6A and 6B are provided on the upper end surfaces of the primary winding 3A and the secondary winding 3B to press the windings in the F direction.
A winding receiver 7 that commonly receives the windings is arranged on the lower end surface of the primary winding 4A and the secondary winding 4B. The press rings 6A, 6B are configured to obtain a pressing force in the F direction based on an upper frame (not shown) formed on the upper part of the press rings, and the winding receiver 7 is formed on the upper frame (not shown) formed on the lower part of the press rings 6A, 6B. Not fixed to the bottom frame.

FIG. 10 is a sectional view taken along the line Q--Q in FIG. An intermediate ring 5A interposed between the primary windings 3A and 4A is composed of insulating rings 8A, 8B and an insulating spacer 9, and a through hole 10 through which the intermediate yoke 2B passes is formed in the intermediate ring 5A. ing. Furthermore, intermediate yoke 2B
is held between clamping plates 11, and bolt holes 12 are drilled through the silicon steel plates including the clamping plates 11 in the stacking direction, and bolts 13 are inserted into the bolt holes 12.
is inserted and the silicon steel plate is tightened with a nut 14.

The intermediate ring 5A is formed to go around the main leg 1, and its through hole 10 is provided at a location where it intersects with the intermediate yoke 2B. The intermediate yoke 2B is formed to have a gap with the intermediate ring 5A and not to come into contact with the intermediate ring 5A. The reason for this is that when this rectifier transformer is manufactured in Fig. 9, the primary windings 3A and 4A are tightened by pressing the press ring 6A in the F direction, but the primary windings 3A and 4A and the intermediate ring This is to prevent the insulating rings 8A and 8B shown in FIG. 10 from hitting the intermediate yoke 2B since the insulating material composing the yoke 5A contracts due to the pressing force. Insulation ring 8A, 8
When B hits the intermediate yoke 2B, it becomes impossible to tighten the primary winding 4A after that, and the mechanical strength of the primary winding 4A decreases. A similar through hole is also provided in the intermediate ring 5B, and its configuration is exactly the same as that in FIG. 10. The primary windings 3A, 4A and the secondary windings 3B, 4B are configured to be pressed separately by press rings 6A, 6B, respectively. This is because the compressed dimensions of the primary windings 3A, 4A and the secondary windings 3B, 4B are different even though the pressing force is the same.

[0007]

However, the conventional device as described above has the drawback that the intermediate ring must be made of a thick insulating material, which increases the axial dimension of the winding.

[0008] The role of the intermediate ring is to press each winding group with uniform surface pressure, and if the ring itself bends, it will no longer be able to transmit uniform pressure to the winding groups. However, since the intermediate ring has a through hole for passing the intermediate yoke through, conventional devices require a material that is thick in the axial direction for the intermediate ring in order to eliminate deflection at the through hole portion. In FIG. 10, if a thin material is used as the insulating ring 8A of the intermediate ring 5A, the through hole 1
Since the width of 0 is several 100 mm, the insulation ring 8A,
8B bends as shown by dotted lines 15A and 15B. Therefore, the tightening pressure is insufficient and the mechanical strength of the primary windings 3A and 4A is reduced. If the primary windings 3A, 4A have high rigidity, they will not bend as much as the dotted lines 15A, 15B, but since the conductors of the windings are made of copper or aluminum, they are easily deformed, and the insulating rings 8A, 8B
It was necessary to increase the axial thickness of the The same applies to the intermediate ring 5B.

An object of the present invention is to make the intermediate ring thinner than conventional devices by configuring the intermediate yoke to be free in the axial direction of the main landing gear, thereby reducing the axial dimension of the entire winding. be.

0010

[Means for Solving the Problems] In order to achieve the above object, the present invention provides three main legs laminated with magnetic steel plates, and a separate main leg at both ends of the main legs in the axial direction. a plurality of winding groups arranged at shifted positions in the axial direction of each main leg, each consisting of an end yoke that magnetically connects the main legs, and a primary winding and a secondary winding that wind the main legs; , an intermediate ring made of an insulator interposed between each of these winding groups, and a through hole provided in this intermediate ring, and a magnetic and an intermediate yoke connected to the intermediate yoke, the intermediate yoke is sandwiched between the intermediate ring via a cushion layer loaded in a through hole of the intermediate ring, and both axial ends of the intermediate yoke are Each of the surfaces is butt-jointed to the main leg, and in this configuration, the intermediate yoke is formed of magnetic steel plates laminated in a direction 90 degrees different from the lamination direction of the magnetic steel plates forming the main leg. shall be taken as a thing. Furthermore, in the above, the intermediate yoke and the main leg are simultaneously held and tightened from the stacking direction of the main leg magnetic steel plates by a pair of clamping plates made of plates longer than the entire axial length of the intermediate yoke.

[0011]

[Operation] According to the structure of the present invention, the intermediate yoke is held between the intermediate rings via the cushion layer loaded into the through hole of the intermediate ring, and both end surfaces of the intermediate yoke and the main leg are butted and joined. Ta. Therefore, the intermediate yoke becomes free in the axial direction of the main landing gear at the joint with the main landing gear. Therefore, even if the insulators constituting the winding group contract when the winding group is pressed by the press ring, the intermediate yoke and the intermediate ring move together, so that even surface pressure is applied to the winding group. It takes. Further, since the cushion layer is loaded in the through hole, the intermediate yoke receives surface pressure from the cushion layer, so that the intermediate ring does not bend. Therefore, there is no need to increase the axial thickness of the intermediate ring so much, and the axial dimension of the entire winding becomes smaller.

Further, in the above structure, the intermediate yoke is formed of magnetic steel plates laminated in a direction 90 degrees different from the lamination direction of the magnetic steel plates forming the main leg. With this configuration,
An intermediate yoke is held between the windings. Therefore, the bolt hole for tightening the magnetic steel plate and the bolt passing through the bolt hole, which were necessary in the conventional device, are no longer necessary. Therefore, the axial dimension of the winding of the intermediate yoke can be reduced, thereby further reducing the axial dimension of the entire winding.

Further, in the above structure, the intermediate yoke and the main leg are simultaneously clamped and tightened from the direction in which the main leg magnetic steel plates are laminated by a pair of clamping plates made of plates longer than the entire length of the intermediate yoke in the axial direction. With this configuration, the end of the clamping plate hangs over the main landing gear, so the intermediate yoke is free against the movement of the main landing gear in the axial direction, but it is supported so that it does not move in the stacking direction of the main landing gear magnetic steel plates. be done.

[0014]

EXAMPLES The present invention will be explained below based on examples. FIG. 1 is a front view showing the configuration of a rectifier transformer core according to an embodiment of the present invention. It is composed of three main legs 16, an upper end yoke 2A, an intermediate yoke 17, and a lower end yoke 2C. The difference from the conventional device in Fig. 8 is the intermediate yoke 1.
7 and the main landing gear 16. The end surface of the intermediate yoke 17 is formed into a plane perpendicular to its axial direction, and by making the end surface of the intermediate yoke 17 and the surface of the main leg 16 face each other, the intermediate yoke 17 and the main leg 16 are butted. It is joined. Therefore, the movement of the intermediate yoke 17 is the same as that of the main landing gear 16.
The main landing gear 16 is free in the axial direction at the joint with the main landing gear 16.

FIG. 2 is a cross-sectional view showing the main structure of a rectifier transformer according to an embodiment of the present invention. The only difference from the conventional device shown in FIG. 9 is that the iron core is constructed from the same as shown in FIG. Detailed explanation will be omitted by using the same reference numerals for the same parts as in the conventional device. FIG. 3 is a sectional view taken along line PP in FIG. 2. An intermediate ring 18A interposed between the primary windings 3A and 4A is composed of insulating rings 20A and 20B, and a through hole 21 through which the intermediate yoke 17 passes is formed in the intermediate ring 18A. The intermediate yoke 17 has a bolt 13 inserted into a bolt hole 12 passing through the clamping plate 11 in the same way as in the conventional device shown in FIG.
The silicon steel plate is tightened by a nut 14. Further, the intermediate yoke 17 is sandwiched between insulating rings 20A and 20B with a cushion layer 19 in between. Note that the intermediate ring 18B sandwiched between the secondary windings 3B and 4B in FIG. 2 also has a configuration exactly the same as that in FIG. 3.

By being configured as shown in FIGS. 2 and 3, when the winding groups 3 and 4 are pressed by the press rings 6A and 6B, the winding groups 3 and 4 and the intermediate ring 18A
, even if the insulator constituting 18B contracts, the intermediate yoke 17
Since the intermediate rings 18A and 18B move together, an equal surface pressure is applied to the winding groups 3 and 4. Further, since the cushion layer 19 is loaded in the through hole 21 and the intermediate yoke 17 receives the surface pressure thereof, the intermediate yoke 17 does not bend toward the through hole 21 side as in the conventional device. Therefore, there is no need to increase the thickness of the through holes 21 of the insulating rings 20A, 20B so much. The cushion layer 19 is made of, for example, a rubber material. When the intermediate rings 18A, 18B are pressed through the winding groups 3, 4, the intermediate yoke 17 does not contract, but the insulating rings 20A, 20B around it contract. The cushion layer 19 has the role of absorbing the shrinkage of the insulating rings 20A, 20B and also absorbing the unbalance of the shrinkage between the primary windings 3A, 4A and the secondary windings 3B, 4B.

FIG. 4 is a cross-sectional view showing the main structure of a rectifier transformer according to another embodiment of the present invention. The intermediate yoke 22 is formed of silicon steel plates laminated in a direction 90 degrees different from the lamination direction of the silicon steel plates forming the main leg. The position of the cross section in FIG. 4 corresponds to the PP position in FIG. Intermediate ring 18 interposed between primary windings 3A and 4A
A is composed of insulating rings 20A and 20B,
A through hole 21 through which an intermediate yoke 22 passes is formed in the intermediate ring 18A, and the intermediate yoke 22 is sandwiched between insulating rings 20A and 20B with a cushion layer 19 in between.

By configuring as shown in FIG.
Bolt 1 for tightening the silicon steel plate required in the configuration of
3 becomes unnecessary. In the conventional device shown in FIG.
It is possible to reduce the dimension of the intermediate yoke in the winding axial direction, which was necessary to some extent in order to ensure the following. Therefore, it is possible to keep the cross-sectional area of the intermediate yoke 22 within a value required in the original magnetic circuit. This configuration further reduces the axial dimension of the entire winding and also reduces the weight of the entire device since no clamping plate is required. In addition, in the configuration of FIG. 4, the intermediate yoke 22 is arranged in the width direction (
It is also possible to have a structure in which the core is divided into two parts (left and right in the figure) and a cooling duct is interposed in the middle, which facilitates cooling of the core.

FIG. 5 is a perspective view showing the structure of an intermediate yoke of a rectifier transformer according to still another embodiment of the present invention. The intermediate yoke 26 is held between clamping plates 27 and 28 which are longer than the entire axial length of the intermediate yoke 26 via bolts 29.

FIG. 6 is a sectional view showing a structure in which the intermediate yoke of FIG. 5 is assembled to the main leg. The direction perpendicular to the plane of the paper is the axial direction of the main landing gear 30. Both ends of the tightening plates 27 and 28 are sandwiched between the main legs 30 and tightened.

[0021] Since the ends of the clamping plates 27 and 28 hang on the main leg 30, the intermediate yoke 26 is attached in the axial direction of the main leg 30.
Although it moves freely in the direction perpendicular to the plane of the paper in Figure 6, it does not shift in the direction in which the main landing gear silicon steel plates are laminated (in the vertical direction of the plane of the paper in Figure 6). In the configuration shown in FIG. 3 or 4, there was a possibility that the intermediate yoke would shift due to acceleration during transportation of the transformer, but with the configuration shown in FIG. 6, this shift can be prevented.

FIG. 7 is a front view showing the configuration of a rectifier transformer core according to still another embodiment of the present invention. 3
Main leg 23, upper end yoke 2A, intermediate yoke 24,
25 and a lower end yoke 2C. The end faces of the intermediate yokes 24 and 25 are formed into planes perpendicular to the axial direction, and the end faces of the intermediate yokes 24 and 25 and the main leg 2
3 are butt-jointed.

While the core in FIG. 1 constitutes a two-story winding group, the core in FIG. 7 constitutes a three-story winding group, and is generally an n-story winding group. An iron core that constitutes a winding group can be formed. By forming the winding group into n stories, it is possible to output n approximately the same secondary voltages from the same primary voltage through the n winding groups having different connection structures. In the case of an n-story building, the intermediate yoke and the main leg are butt-jointed as shown in Figure 7, and the intermediate ring and intermediate yoke are sandwiched as shown in Figure 3 or 4. The axial dimension of the entire line can be reduced, and this dimension reduction effect increases as n increases. Furthermore, the structure in which the intermediate yoke 26 is held between the clamping plates 27 and 28 as shown in FIG. 6 can be applied even to an n-story building.

[0024]

[Effects of the Invention] As described above, the present invention has a structure in which the intermediate yoke and the main leg are butt-jointed, and the intermediate yoke is sandwiched between the intermediate ring via a cushion layer loaded into the through hole of the intermediate ring. And so. As a result, the axial thickness of the intermediate ring can be made smaller than in conventional devices, so the axial dimension of the entire winding can be reduced, making it possible to provide an overall compact device. Furthermore, the present invention can be applied to a device with an n-story winding group, and has the advantage that the larger the value of n, the greater the effect of reducing the size of the entire winding in the axial direction.

Further, in the above structure, the intermediate yoke is formed of magnetic steel plates laminated in a direction 90 degrees different from the lamination direction of the main leg magnetic steel plates. This makes it possible to reduce the axial dimension of the winding of the intermediate yoke, making it possible to further reduce the axial dimension of the entire winding, and eliminating the need for a tightening plate, resulting in an overall weight reduction compared to conventional equipment. It is possible to provide a device with moreover,
Since the intermediate yoke can be divided and arranged via the cooling duct, the intermediate yoke can also be cooled.

Furthermore, in addition to the above configuration, the intermediate yoke and the main leg are simultaneously clamped and tightened by a tightening plate made of a plate longer than the entire length of the intermediate yoke in the axial direction. This makes it possible to configure a three-phase core that does not shift in the lamination direction of the main landing gear magnetic steel plates. Therefore, even if the transformer is subjected to acceleration during transportation, it will not be deformed, and a highly reliable device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the configuration of a rectifier transformer core according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the configuration of main parts of a rectifier transformer according to an embodiment of the present invention.

[Figure 3] Cross-sectional view taken along line P-P in Figure 2

FIG. 4 is a sectional view showing the configuration of main parts of a rectifier transformer according to a different embodiment of the present invention.

FIG. 5 is a perspective view showing the configuration of an intermediate yoke of a rectifier transformer according to still another embodiment of the present invention.

[Figure 6] A sectional view showing a configuration in which the intermediate yoke in Figure 5 is assembled to the main leg.

FIG. 7 is a front view showing the configuration of a rectifier transformer core according to still another embodiment of the present invention.

[Figure 8] Front view showing an example of the configuration of a conventional rectifier transformer core

[Fig. 9] A cross-sectional view showing an example of the main part configuration of a conventional rectifier transformer.

[Figure 10] Cross-sectional view taken along the Q-Q line in Figure 9

[Explanation of symbols]

16 Main landing gear 23 Main landing gear 30 Main landing gear 2A Upper end yoke 2C Lower end yoke 17 Intermediate yoke 22 Intermediate yoke 24 Intermediate yoke 25 Intermediate yoke 26 Intermediate yoke 3 Winding group 4 Winding group 3A primary winding 4A primary winding 3B Secondary winding 4B Secondary winding 18A intermediate ring 18B Intermediate ring 6A Press ring 6B Press ring 7 Winding receiver 20A Insulation ring 20B Insulation ring 21 Through hole 11 Tightening plate 27 Tightening plate 28 Tightening plate 12 Bolt hole 13 bolt 29 bolts 14 Nut 19 Cushion layer

Claims (3)

[Claims] Claim 1: Three main legs laminated with magnetic steel plates, an end yoke that magnetically connects the main legs at both ends of the main legs in the axial direction, and a winding around the main legs. It consists of a plurality of winding groups arranged at shifted positions in the axial direction of each main landing gear, and an insulator interposed between each of the winding groups. An intermediate ring, and an intermediate yoke that passes through a through hole provided in the intermediate ring and magnetically connects the main legs in the middle in the axial direction of the main legs, wherein the intermediate yoke is The intermediate yoke is sandwiched by the intermediate ring via a cushion layer loaded into a through hole of the intermediate ring, and both end surfaces of the intermediate yoke in the axial direction are butt-jointed to the main leg, respectively. Rectifier transformer. 2. A rectifier according to claim 1, wherein the intermediate yoke is formed of magnetic steel plates laminated in a direction 90 degrees different from the lamination direction of the magnetic steel plates forming the main leg. transformer. 3. The device according to claim 1 or 2, wherein the intermediate yoke and the main leg are simultaneously held between the intermediate yoke and the main leg from the laminating direction of the main leg magnetic steel plates by a pair of clamping plates made of a plate longer than the entire axial length of the intermediate yoke. A transformer for a rectifier, which is characterized by being tightened.