JPH0480623B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flat coil that can be used in axial gap type rotating electric machines such as printed motors, multiphase alternating current generators, flat motors, etc.
The present invention relates to the structure of a flat coil comprising a support disk made of an insulating material and a plurality of coil pieces made of thin conductors arranged and fixed in layers and substantially radially to the support disk.

This type of flat coil is arranged in an axial gap type rotating electrical machine with both sides of the flat coil facing magnets. That is, for example, in the case of an axial air gap type generator, a flat coil is used as a stator coil, and magnets are fixed to a pair of rotors attached to the shaft and face both sides of the stator coil, so that when the rotor rotates, the coil An induced electromotive force is generated within the To be more specific, the magnets of the rotor face the part of each piece of the flat coil located between the inner and outer ends in the radial direction, and this part is effective in generating the induced electromotive force. This part will be called the "effective part".

By the way, the flat coils of conventional axial gap type rotating electric machines are made of round wires of a constant thickness, such as those found in flat motors, or coil pieces with a constant wall thickness (plate thickness), such as those found in printed motors. Ta.
Due to the structure of this type of rotating electrical machine, the temperature becomes higher as the radially inner part of the flat coil and the axially inner part of the flat coil become closer, making cooling difficult. In addition, as printed motors, flat motors, alternating current generators, etc. become higher output and smaller, the temperature of the entire flat coil used in these rotating electric machines tends to rise, and it is difficult to prevent the coil temperature from rising. It has become necessary. Additionally, there has been a need to reduce the air gap between the magnets.

The present invention relates to a structure of a flat coil disposed between a pair of magnetic poles of a rotor having a pair of magnetic poles facing each other in the axial direction of a rotating shaft and generating magnetic flux in the axial direction, the flat coil being made of an insulating material. It has a support disk made of aluminum, and a plurality of coil pieces made of a thin conductor arranged and fixed to the support disk in layers and substantially radially, each coil piece having a radially inner end portion. and an outer end portion, and an effective portion located between these end portions and arranged between the pair of magnetic poles, and the axial thickness of at least the effective portion of the outermost coil element is equal to that of the inner layer. It is characterized by being smaller than the axial wall thickness of the effective portion of the coil piece.

According to the flat coil of the present invention, since the wall thickness of the effective part of the outermost layer coil piece is thin, heat generation is concentrated in this effective part, and cooling air is directed to the effective part of the outermost layer coil piece where this heat generation is concentrated. Since it hits directly, it has the effect of improving the heat dissipation effect. Moreover, since the effective part of the outermost coil element is thin, it is possible to reduce the air gap, making it possible to increase the amount of magnetic flux in the air gap, without increasing the size of the rotating electric machine. This makes it possible to increase output. Furthermore, since only the outermost layer coil piece has a thinner part than the inner layer coil piece,
It also has the advantage of being easy to manufacture.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, a flat coil 10 has a large number of coil pieces 12 arranged and fixed radially on a support disk 11 made of an insulating material, and each coil piece 12 has an annular area indicated by B in the figure. The coil fin 1 has an effective part located inside the effective part, and end parts radially inward and outward of the effective part, and the most extreme parts of these end parts are bent in the axial direction as described below.
6, 17 are formed. In Figure 1, 1
8 is an outer holder, 19 is an inner holder, and 18a and 19a are holder fins. There is a circular opening in the center of the flat coil 10, through which the shaft of a rotating electrical machine is passed.

The coil pieces 12 are not provided only on the outer surface of the support disk 11, but are provided in layers as described below.

FIG. 2 is a radial cross-sectional view of the flat coil 10 shown in FIG. 1, but strictly speaking, it is not a cross-sectional view cut along one plane, but a cross-sectional view of all the coil pieces of all layers. It is, so to speak, a composite cross-sectional view that is displayed within.

As clearly shown in FIG. 2, the flat coil 10 has four layers of coil pieces 12a,
12b, 12c, 12d and insulating material layers 11a, 11b, located between the layers of these coil pieces.
11c. When creating one, two layers of coil pieces 12a, 12b and an insulating material layer 11a are used.
Another unit 10b is formed from the remaining two layers of coil pieces 12c and 12d and the insulating material layer 11c, and these two units 10a and 10b are connected via the third insulating material layer 11b. They may be stacked together in a structure as shown in the drawings. In the flat coil 10 having this laminated structure, the coil pieces 12a and 12d are called "outermost coil pieces", and the coil pieces 12b and 12c are called "outermost layer coil pieces".
is called the "inner layer coil piece."

Coil pieces 12a to 12d are insulating material layer 11
The insulating material layers 11a, 11c are arranged in a pattern as shown in FIG.
Projects from both outer edges. 10 units each
a, 10b, insulating material layer 11a or 11
The radially outward and inward protruding ends of the coil piece 12a or 12d on the first surface of c are the radially outward and inward protruding ends of the coil piece 12b or 12c on the second surface. The windings of the coil are electrically connected by welding, brazing, etc., and the protruding ends connected in this way are bent in the axial direction as shown in FIG. 2 to form the coil fin 1.
6, 17.

FIG. 3 is an enlarged view of the main part of FIG. As is clear from this figure, the inner layer coil pieces 12b and 12c have a uniform wall thickness (thickness in the axial direction of the flat coil) t ₁ over their entire length, but the outermost layer coil piece 12a , 12d are not uniform over their entire length. That is, the outermost layer coil pieces 12a and 12d have a wall thickness t ₁ equivalent to the wall thickness t ₁ of the inner layer coil pieces 12b and 12c at their radially outer and inner end portions. However, in the effective portion B, the wall thickness t ₂ is smaller than t ₁ .

FIG. 4 is a diagram showing a flat alternator 20 using the flat coil 10 described above. Flat coil 10
The outer peripheral edge of the flat coil 10 is sandwiched between the housings 24a and 24b, and a pair of rotors 22a and 22 are mounted on both sides of the flat coil 10 with a predetermined axial gap therebetween.
b is arranged and keyed to the shaft 26. The shaft 26 includes housings 24a and 24b.
Bearings 27a and 27b respectively fixed to
is rotatably supported by a pulley 28 at one end.
is connected to. Permanent magnets 22c and 22d are embedded in the rotors 22a and 22b, respectively, and face the flat coil 10. With the above configuration,
When the rotors 22a and 22b are rotated by a drive device (not shown) via the pulley 28 and the shaft 26, an induced electromotive force is generated in the flat coil 10, which is rectified by the thyristor regulator 29 and sent to the output terminal 30. It is output after passing through.

Vanes 22a', 22a'', 22 forming suction fans are disposed on the axially outer surfaces of the rotors 22a, 22b.
b', 22b'' are provided, and when the rotor rotates, air is drawn into the housing 24 by the action of these vanes.
It is sucked in through the windows provided in the end walls of the housings 24a and 24b and flows in the direction of the arrow, and flows out through the windows 24a' and 24b' formed in the peripheral wall of the housing to cool the inside of the generator. ing. This cooling air also flows along the surface of the flat coil 10 and cools the coil. In this case, in the flat coil 10 according to the present invention, the outermost coil pieces 12a and 12 of the coil pieces constituting the winding of the coil are
Since the axial wall thickness _t2 of the effective portion B of d is smaller than the wall thickness t1 of the inner layer coil pieces _12b and 12c, heat generation due to resistance loss is generated more in the outermost layer coil pieces 12a and 12d than in the inner layer. The cooling efficiency of the flat coil 10 is high because it occurs more on the surface of the coil that is in direct contact with the cooling air. Moreover, in the generator 20 using the flat coil 10 having the above-described structure, the magnets 22c and 22d of the rotors 22a and 22b are
Since the distance between the two is small, the amount of magnetic flux in the air gap increases, which also has the effect of increasing the output of the generator. These effects cannot be obtained simply by reducing the wall thickness t ₁ of the inner and outer coil pieces 12a to 12d to t ₂ . That is, if the wall thickness of all the coil pieces is simply reduced, the DC resistance of the inner layer coil pieces will increase, and heat generation loss will increase.

In the above embodiment, the coil pieces 12a to
12d is formed by punching out a material with a certain thickness using a press or the like, and the outermost coil pieces 12a, 12d
The thickness of the effective part B was reduced by cutting the material. However, it is also possible to use a press to reduce the wall thickness from t ₁ to t ₂ or use already known electrolytic or electrodeposition techniques. Alternatively, the coil piece may be die-cast.

Further, in the above embodiment, the coil pieces are arranged in four layers, but the technical concept of the present invention also includes coil pieces in more layers than that.

[Brief explanation of the drawing]

Figure 1 is a front view of the flat coil. FIG. 2 is a radial cross-sectional view of a flat coil, showing a coil structure according to an embodiment of the present invention. Figure 3 is an enlarged view of the main parts of Figure 2. FIG. 4 is a partially sectional side view of a flat AC generator using the flat coil of the present invention. 10...Flat coil, 11...Support disk, 11a~
11c...Insulating material layer of support disk, (12a, 12
b, 12c, 12d)-12...Coil piece, B...
Effective part of each coil piece, t ₁ , t ₂ ... Axial wall thickness of the coil piece.

Claims (1)

[Scope of Claims] 1. A structure of a flat coil disposed between a pair of magnetic poles of a rotor having a pair of magnetic poles that face each other in the axial direction of a rotating shaft and generate magnetic flux in the axial direction, , having a support disk made of an insulating material, and a plurality of coil pieces made of thin conductive material arranged and fixed in layers and substantially radially on the support disk, each coil piece being arranged in a radial direction. It has an inner end portion, an outer end portion, and an effective portion located between these end portions and arranged between the pair of magnetic poles, and has an axial wall thickness of at least the effective portion of the outermost coil element. is smaller than the axial wall thickness of the effective portion of the inner layer coil piece.