JPS60237831A - Cooling structure of rotary electric machine - Google Patents

Abstract

PURPOSE:To enable the cooling function to be realized effectively while lowering the current density of flat coils, by a method wherein non-effective sections of coil pieces are protruded to an axial line and the stator blade and radiation fin are formed in a rotary electric machine which is provided with the flat coils for the stator. CONSTITUTION:Coil pieces 13, 13' are attached to the front and back faces of an insulating substrate 12 on a disc, to form flat coils 6, and in a rotary electric machine fixing the flat coils 6 to a housing, non-effective sections 18b, 18c set outside and inside the coil pieces 13, 13' are protruded toward an axial line to form salient sections 40a, 41a. The salient sections 40a, 41a are arranged so that the function of the stator blade for cooling air and of the radiation fin for the coil pieces 13, 13' and for the stationary blade may be performed. As a result, the sectional areas of the coil pieces 13, 13' are made larger, and so current density is lowered and satisfactory radiation effect can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling structure for a rotating electrical machine, and particularly relates to a cooling structure for a rotating electrical machine having a flat coil incorporated in the stator of an alternating current generator for a vehicle using permanent magnets. .

(Prior art) It is known that flat coils for rotating electric machines are made by bonding steel plate coil pieces to serve as conductors on an insulating substrate. When trying to create a small, high-output generator by interlinking rotating magnetic fields,
The current flowing through the coil piece of this flat coil 1 generates heat in the coil 1 itself, which has the drawback of causing the flat coil to become abnormally hot.

(Object of the Invention) The object of the present invention is to eliminate the drawbacks of the prior art mentioned above, and to obtain a cold fJ structure for a rotating electrical machine that can lower the current density of the flat coil and provide strong cooling.

(Structure of the Invention) A cooling structure for a rotating electrical machine according to the present invention includes an approximately disk-shaped insulating substrate in which a hole through which the rotating shaft of the rotating electrical machine passes is formed in the center, and fixed substantially radially on the front and back of this insulating substrate. The front side coil piece and the back side coil piece each have flat coils connected at opposite ends, and the ineffective portions of the inner and outer diameters of each coil piece rotate. It protrudes in the direction of the l1II line of the axis to form stator vanes and radiation fins, which effectively cool the flat coil (Example) Next, the attached drawings are shown. A preferred embodiment of the present invention will be described with reference to the following.

FIG. 1 is a partially sectional side view of a vehicle alternator having a cooling structure according to the present invention. In the figure, reference numeral 1 denotes a pulley driven by a vehicle engine (not shown) via a belt (not shown). A rotating shaft 2 coupled to this pulley 1 is supported by front and rear bearings 3a and 3b. The front bearing 3a is attached to a front housing 4a made of aluminum, and the rear bearing 3b is attached to a rear housing 4bc. Both housings 4a, 4b are joined at their ferro-contact surfaces, and are connected to each other by tightening bolts (not shown).

A pair of rotors 5a and 5b are attached to the rotating shaft 2 so as to rotate together. A flat coil 6 is connected to the rotor 5a between the rotors 5a and 5b.

51) so as not to interfere with it.

The flat file 6 is a protrusion 40a shown in FIG.

40'a and a thermally conductive insulating sheet 7 made of boron and glass cloth are interposed to form the front housing 4a.

41).

Since the front rotor 5a and the rear rotor 5b have substantially the same shape, only the rear rotor 5b will be described in detail with reference to FIGS. 2, 3, and 4.

As shown in the figure, the rotor 51) is approximately disk-shaped, and has intake holes 8b formed on its inner circumferential side. Inside these intake holes 8b, there are first scoops 9b that take in air when the rotor 5b rotates. They are installed as shown in Figures 3 and 4.

On one side of the rotor 51), segment type permanent magnets 10 for field are arranged in the circumferential direction and fixed by claws 11 formed on the rotor 5b. Symbol N of the permanent magnet 10 shown in FIG.

S indicates the polarity of magnetization, and the field magnetic flux flows from right to left in FIG. 1 in parallel to the axial direction of the rotating shaft 2 and passes through the flat coil 6.

In FIG. 1, the reference numeral 8a indicates an intake hole of the front rotor 5a, which is symmetrical in shape to the intake hole 8b of the rear rotor 5b, and the reference numeral 9a indicates an air intake hole similarly attached to the front O-tor 5a. Showing the scoop.

As shown in FIG. 1, the flat coil 6 has a central insulating substrate 12 and a large number of elongated coil pieces 13, 13' attached almost radially on both sides of the central insulating substrate 12, and is a wave-wound three-phase coil (Y-connection) as a whole. is formed.

The output of the flat coil 6 is connected to the thyristor bridge 15 by a lead wire 14, and the three-phase AC output from the flat coil 6 is converted to a predetermined DC voltage.
6 to an external electrical load.

In the generator having the above structure, when the pulley 1 is driven by the engine, the rotors 5a and 5b rotate, and the flat coil 6 generates an alternating current output as is well known. That is, this flat coil 6 constitutes an armature coil provided on the stator side of the generator.

The scoop 9a is created by the rotation of the rotors 5a and 5b.

Reference numeral 9b indicates a ventilation hole 17a formed in the housings 4a, 4b as shown by the arrows in FIG.

17b, and passes through the gap between the front and back surfaces of the flat coil 6 and the field permanent magnet 10, that is, the ventilation groove 10a, while cooling the flat coil 6 from the inner circumferential side to the outer circumferential side of the flat coil 6. It flows approximately in the radial direction and is finally discharged to the outside through the ventilation window 17c formed in the front housing 4a.

Next, details of the flat coil 6 will be explained with reference to FIG. 6.

It is made of mica and has a disk shape with a uniform thickness. The coil pieces 13 and 13' attached to the front and back sides of this insulating substrate 12 are formed by forging copper plates by the method described later, and the coil pieces 13 on the front side (Fig. 5) are insulated with a gap d5 between them. The coil pieces 13 are arranged on a substrate 12, and a ceramic adhesive 22 is inserted between the coil pieces 12, thereby fixing each coil piece 13 almost radially from the inner circumferential side to the outer circumferential side of the insulating substrate 12. . Fifth
Similarly to the coil pieces 13 on the front side, the coil pieces 13' on the back side indicated by dotted lines in the figure are fixed to the back side of the insulating substrate 12 in a substantially radial manner with an interval of LI-3.

Then, the corresponding front and back coil pieces 13. The outer peripheral end of 'i3' is connected to the joint 208 by argon welding at 13, as shown in FIG. 6 (arrow V1 view in FIG. 5). The inner circumferential end of the coil piece 13, 13' has a transition portion 19a that protrudes radially inward from the insulating substrate 12, as shown in FIGS. 5 and 7 (see arrow VII in FIG. 5). , the transition part 1 of the coil piece 13' on the back side corresponding to this
9b and the joint portion 20b as shown in FIG. 7, and are connected by -C argon welding. In this way, the coil piece 13a on the front side is connected to the coil piece 13'b on the back side, and the coil piece 13b on the front side is connected to the coil J-i 13'a on the back side, and the set of coil pieces 13.13' is a three-phase coil. is formed. This winding method is described, for example, in U.S. Patent No. 3,23
The technique of three-phase alternating current wave winding of a flat coil disclosed in Japanese Patent No. 1,774 can be used.

Next, the shape of the front coil piece 13 will be explained in more detail with reference to FIGS. 8 to 1.0.

There are two types of coil pieces 13a on the front side.

13b, which face the permanent magnets 10 and interlink with the future field v1111b to generate an induced voltage inside; Ineffective portion 181 that does not interlink with the field magnetic flux
), 18c.

Each effective portion 18a of each coil piece 13a, 13b is finished in a shape in which the thickness in the same direction as the field magnetic flux, that is, in the axial direction, is as thin as possible. On the other hand, the ineffective portion 18
b, 18c are axially protruding portions 40a that are thicker in the axial direction;

41a, 40b, and 41b are formed and act as stator vanes to guide the cooling fluid sucked by the scoops 9a and 9b in the radial direction of the flat coil 6, and at the same time reduce the current density inside the coil. At the same time, it acts as a heat dissipation fin for absorbing and dissipating heat generated in the effective portion 18a by conduction.

In the embodiment shown in FIGS. 1 to 11, the coil piece 1
The protrusions 40a and 41a of the coil piece 3a are higher than the protrusions 40b and 41b of the coil piece 13b, respectively. Coil pieces 13'a, 1 attached to the back side of the insulating single plate 12
3'l> also has the same shape as the front side coil pieces 13a, 13b, and as shown in FIGS. 1, 6 and 7, a high protrusion 40'8.41'a and a low protrusion. 40
'b.

41'b. When these coil pieces 13 and 13' are combined via the insulating plate 12, the innermost joint portions 20b alternately protrude in the axial direction, as shown in FIGS. 6 and 7, and thereby the joint portions 20a , 20b can be easily performed without interfering with adjacent coil pieces. That is, since the welding position is shifted and separated in the axial direction of the rotating shaft 2, it becomes easier for the welding tool to enter.

In addition, as shown in FIG. 12, which is the second embodiment, the transition portion 19a of the coil piece 138.13'a.

By making the lengths of the 19b in the inner radial direction different, the positions of the joint parts 20b are made to alternately protrude inward in the radial direction of the flat coil 6. These welds can be easily performed in the same way as J'3.
0 Since they are shifted apart from each other in the radial direction, it becomes easier for the welding tool to enter.

These coil pieces 13, 13' can be formed by cold rolling a copper plate and then press working, and an example of this method will be described with reference to FIGS. 13 to 16.

First, the copper plate 25 as a raw material is placed on the roller 2 as shown in FIG.
6, the material 25 is cold-rolled into a tapered shape, and then an angle is given to the tapered material 25 using press dies 27 and 28, as shown in FIG. The coil material 25, which has been cut into 1q in this manner, is formed into a coil by using a die 30 and a bunch 29 as shown in FIG. 15 to form a coil piece 13a shown in FIG. Draw an I in the shape. The coil pieces 13a and 13b punched out in this manner are arranged alternately as shown in FIG. This accurate positioning is achieved by installing the jig 31 in FIG.
3. Ic is positioned in this way.
A ceramic adhesive 22 is inserted into the gap between the coil pieces 13a and 13b to insulate the coil pieces 13a and 13b and fix them to the insulating substrate 12.

Similarly to the front side coil pieces 13a and 13b, the back side coil pieces 13'a and 13'b are also manufactured, and the front side coil piece 1
3a and 13b in the manner described above. And each coil piece 13a, 13b, 13'a
, 13'b at the corresponding end connections 20a, 20b
The flat coil 6 is fabricated by connecting the coils (FIGS. 6 and 7) by argon welding as described above.

Next, detailed structures of the rotors 5a and 5b will be explained.

Portions 5a and 5b shown in FIG. 1 are, for example,
This is an improved version of the rotor according to the prior art described in No. 17/1.648, and the air volume is increased.

The amount of heat generated in the coil pieces 13, 13' of the flat coil 6 is radiated by the protrusions 40a, 40' necessary to conduct heat from the protrusions 40a, 40'a to the housings 4a, 4''b. a and housing 4a, 4
b and the ineffective portion 18b.

The surface area of the heat dissipation fin of 18C (Figures 8 to 11),
It is determined by the amount of air used to cool the portions 18b and 18c of the radiation fins. Therefore, the illustrated rotors 5a, 5
b is devised to increase the amount of this cooling air. That is, the rotor 5a.

51) improves the exhaust fan effect of the magnet side part 23 by making a part of the iron part 42 flush with the side part 23 of the magnet 10, as shown in the most detail in FIG. 16 is enlarged to lower ventilation resistance and increase the amount of cooling air. In addition, a notch 21 is formed on the back side of the magnet 10 of the iron portion 42 to remove unnecessary iron portions to reduce weight.

FIG. 18 shows a cross section of a conventional rotor cut at the same position as FIG. 17 and its magnetic flux distribution.

As understood from this FIG. 18, the back part 21 of the magnet
It will be understood that the magnetic flux density between a and the inter-magnet bridging portion 24 is low, and even if some of the core material in these portions is removed, the effectiveness as a rotor will not be adversely affected. .

Also, the rotor fan effect is scoop 9a.

This is produced by the action of 9b as an intake fan and the action of the side surface portion 23 of FIG. 17 of the rotating permanent magnet 10 as an exhaust fan. In the rotors 5a and 5b shown in FIG. 17, the width of the side surface portion 23 is longer than that in FIG. It has a structure.

(Effects of the Invention) As described above, in the cooling structure for a rotating electric machine according to the present invention, the axial direction of the flat coil is such that at least a part of the ineffective portion of each coil piece of the flat coil forms a radiation fin and a stator vane. The heat dissipation effect is extremely high because it protrudes from -C
It is excellent.

[Brief explanation of the drawing]

1 is a partially sectional side view of a vehicle alternator having a cooling structure according to the present invention; FIG. 2 is an inside elevational view showing one rotor of the alternator shown in FIG. 1; Figure 3 is the second
4 is an external elevational view of the rotor shown in FIG. 2, and FIG. 5 is a main part of the flat coil of the alternator shown in FIG. 1. Partially omitted enlarged view, No. 6
The figure is an enlarged arrow view at Vl in Figure 5, Figure 7 is an enlarged arrow view at Vl in Figure 5, and Figure 8 is a plan view of the coil piece on the front side of the flat coil shown in Figure 5. 9 is a side view of the coil piece shown in FIG. 8, FIG. 10 is a plan view of another coil piece on the front side of the flat coil shown in FIG. 5, and FIG.
10 is a side view of the coil piece shown in FIG. 10, FIG. 12 is a side view of main parts of a flat coil showing another embodiment of the present invention, and FIGS. 13 to 14 are views of FIGS. The drawings show the steps of manufacturing the coil piece shown in the figure, and Fig. 13 shows the state in which the material is rolled, and Fig. 14 shows the state in which the rolled material is given an angle by a press die. Figure, 1st
Figure 5 is a diagram showing a state in which a coil piece is punched out from an angled material using a force and a bunch, and Figure 16 is a plan view of the main part showing a state in which a completed coil piece is placed on an insulating substrate with a jig. , Figure 17 shows the line xX'JI -X in Figure 2.
An enlarged cross-sectional view at 85 at t'JI, FIG.
3 is a diagram showing a cross section and magnetic flux distribution. 2...Rotating shaft, 4a, 4b...Housing, 5a,
5b... Rotor, 6... Flat coil, 10... Permanent magnet, 12... Insulating substrate, 13.13', i3a
, 13b, 13'a. 13'b...Coil piece, 18a...Effective part, 18
b, 18c...Ineffective part, 19a, 19b-#f1 part, 20a, 20b-...Joint part, 40a, 41b, 40'a,, 41'b・
...Protrusion. Agent Akira Asamura Figure 1 Figure 2 Figure 4 Figure 6 Fang Off Figure 8 Figure O 9 Figure 16 Figure Fang 17

Claims (1)

[Claims] (1) In a cooling structure for a rotating electric machine, there is provided a substantially disk-shaped insulating substrate in which a hole is formed in the center, through which a rotating shaft supported by a housing of the rotating electric machine passes, and a substantially radial pattern on the front and back sides of the insulating substrate. The front and back coil pieces have flat coils that are joined at the outermost diameter and innermost diameter joints, and the flat coils are supported by the housing on the outer diameter side. In the structure, each of the coil pieces has a rotating cage cooling structure characterized in that the ineffective portions of the inner and outer diameters protrude in the axial direction of the rotating shaft so as to form stationary blades and radiation fins. , A cooling structure for a rotating electrical machine according to claim 1, wherein ineffective portions of the inner and outer diameters of the coil pieces alternately protrude in the axial direction of the rotating shaft.