JPS6125224Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an iron core used in reactors and the like.

Conventionally, reactors have generally been constructed by winding a wound iron core as shown in FIG. 1 and attaching a support to this, and are often operated by natural cooling or wind cooling. However, in saturable reactors that operate in high magnetic flux density regions, the loss generated in the core is extremely large, and in natural cooling or wind cooling, the core temperature can reach 180℃.
In some cases, the winding wire and the varnish-impregnated material require special materials.

Additionally, in order to prevent electromagnetic short circuits at the end faces between the laminated layers of the wound core, it is ideal to place an insulating plate in contact with the end faces, but this is not a good idea in terms of heat transfer since it is a thermal insulator. do not have. Therefore, a layer of adhesive or varnish with a thickness of several tens of microns is usually used.

By the way, it is possible to use a heat dissipation piece to increase cooling, but when the core weighs several tens to hundreds of kilograms, the electromagnetic vibration caused by the magnetostriction phenomenon is large, and varnishes and adhesives may crack when the heat dissipation piece comes into contact with them. Generally, such a large wound core is not used with a heat dissipating piece using only varnish or adhesive because of the risk of wear and tear. Also,
It is also possible to forcefully cool the wound core with water cooling by contacting it with water cooling, but there is a risk of corrosion due to condensation when the water temperature drops or breakdown of electrical insulation due to condensation. It is undesirable and not practiced to use two pieces of paper in contact with each other.

This invention was made to obtain an iron core that eliminates such defects, and one embodiment of this invention will be described below with reference to Figures 2 and 3. Cooling pieces 3 are attached to both end faces of the wound core 1 perpendicular to the winding direction via insulating plates 2, and these are fastened by a fastening mechanism 4. The cooling pieces 3 are provided with a passage 3a through which cooling water 5 flows, and a cap 3b for an inlet and outlet for the cooling water. Generally, the thermal conductivity in the direction perpendicular to the lamination direction of the iron core (parallel to the lamination surface) is higher than that in the lamination direction of the iron core, being about 10 times higher, and heat is easily transferred to the end faces of each layer. Therefore, the heat generated from the wound core 1 is guided toward the end faces of each layer with good thermal conductivity, reaches the cooling pieces 3 through the insulating plates 2 from the side with good cooling effect, and is carried away by the cooling water passing through the passage 3a, thereby cooling the wound core 1. Furthermore, the clamping force of the clamping mechanism 4 applies a pressure to the iron core 1, insulating plate 2, and cooling plate 3, thereby keeping the contact thermal resistance between the iron core and insulating plate, and between the insulating plate and cooling plate, low.

As shown in detail in FIG. 3, the tightening mechanism 4 is composed of a bolt 41, a nut 42, a washer 43, a disc spring 44, etc. In this case, a combination of parallel and series disc springs, By selecting the size and number of sheets, the pressure welding force can be controlled, and the thermal expansion of the iron core and cooling pieces,
Since it works to absorb changes in pressure contact force due to contraction, it is possible to maintain low contact resistance at all times.

Note that the insulating plate 2 is inserted to maintain good interlayer insulation of the core even at the end faces of the core material width, and is effective in reducing loss of the core as much as possible in applications that operate at high magnetic flux density. It is.

As described above, according to this invention, cooling pieces are laminated on both end faces perpendicular to the lamination direction of the iron core, and an appropriate pressure force is applied to these by the tightening mechanism. By cooling the surface from which heat is most easily conducted, it is possible to effectively cool the iron core, and the contact thermal resistance between the iron core and the cooling piece can be kept low, so that the iron core can be cooled well. Therefore, there is an advantage that easily available and inexpensive materials such as Class B can be selected as the winding insulating material, varnish-impregnated material, and the like. Furthermore, by inserting the insulating plate 2,
Good interlayer insulation of the core can be maintained even at the end faces, and by using a disc spring, an appropriate pressing force can always be obtained even if the core and cooling piece expand and contract due to temperature changes. In addition, since the insulating plate is interposed on the premise of using a water-cooled cooling plate with low thermal resistance, it is thicker than when using varnish or adhesive (for example, it is several tens of times thicker than varnish, etc.). (approximately 0.5 to 1 mm) can be used,
Problems such as cracking and abrasion caused by electromagnetic vibration of the wound core can be solved, and the problem of dew condensation caused by cooling pieces can be alleviated from the effect on the core by interposing the insulating plate. Moreover, a cooling water passage was provided in the cooling piece, and a cap was provided at the entrance and exit of this passage.
This has overall remarkable effects, such as improving cooling performance and making it easier to guide the cooling water to the cooling water passage.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a conventional wind-cooled or self-cooled core, Fig. 2 is a perspective view showing an embodiment of this invention, and Fig. 3 shows details of the tightening mechanism in Fig. 2. FIG. In the figure, 1 is the iron core, 2 is the insulating plate, 3 is the cooling piece, 3
a is a cooling water passage, 3b is a base, 4 is a tightening mechanism, 4
4 is a disc spring.

Claims (1)

[Scope of utility model registration request] Cooling pieces are stacked by contacting both end faces of the iron core at right angles to the stacking direction through insulating plates, and are connected by a tightening mechanism with a disc spring interposed so as to apply pressure between them, and the above-mentioned cooling An iron core characterized in that a cooling water passage is provided in each piece, and a cap is attached to each of the entrances and exits of the cooling water passage.