JPH04172933A - Salient pole rotating type ac generator - Google Patents

Abstract

PURPOSE:To facilitate manufacture and to improve pass rate by making a plurality of axially extending open grooves in the outer peripheral part of a rotor core, forming aluminum alloy diecast rods in the open grooves and integrally coupling aluminum alloy diecast plates to the opposite ends of the rods. CONSTITUTION:A plurality of open grooves 2a are made in the outer peripheral part of a rotor core 2 where the open groove has a cross section in the form of a hooked hole defined by a small circle and two parallel lines. The rotor core 2 is then inserted into a diecast die and pressed axially, thereafter an aluminum alloy is extruded to integrally form a brake winding comprising a plate 3a and a rod 4a. According to the constitution, diecast work is facilitated and pass rate is improved because an inexpensive aluminum alloy having good casting performance is employed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a salient pole field rotating alternating current generator, and particularly to a portable alternator having a rotor provided with a rotor winding and a brake winding. Or it relates to a small salient pole field rotating alternating current generator.

[Conventional technology]

Traditionally, power work equipment equipped with an internal combustion engine as a power source, such as lawn mowers and chemical sprayers, is often equipped with a small generator as a power source. Unlike a generator, it is mainly used as a power source for the spark plug of an internal combustion engine, so there is little consideration for the voltage waveform.1For example, a salient pole field rotating type rotor requires 2 field formation in the rotor core. Most of the configurations are simply wrapped with a winding wire for use.

However, in recent years, power working equipment has appeared that is equipped with computer control means such as electronic governor control, and a generator as a power source for driving such electronically controlled equipment has become available.

As with commercial power generators, voltage waveforms have also come to be evaluated as an important characteristic. On the other hand, as a means for reducing the distortion factor of the voltage waveform, it is known to provide a damper winding on one rotor. Therefore, by providing a brake winding on one rotor even in a small generator mounted on the power working equipment.

It is believed that the distortion factor of the voltage waveform can be reduced.

FIG. 9 is a partially sectional explanatory view showing an example of a conventional salient pole rotor with brake windings. In FIG. 9, reference numeral 1 denotes a shaft, and a rotor core 2, which is made of electromagnetic steel plates formed in a substantially I shape and laminated in the axial direction, is fitted in the middle part of the rotor core 2. A brass plate 3 formed in a shape corresponding to the cross-sectional shape of the iron core 2 is provided, and a copper rod 4 is inserted through the outer periphery of the three-rotor iron core 2, and the brass plate 3 and the copper rod 4 are welded together by brazing. and constitutes a brake winding. Reference numeral 5 designates a rotor winding, which is wound around the first rotor core 2 and forms a salient pole rotor together with the first rotor core 2. Reference numeral 6 designates a slip ring, which is provided near one end of the shaft 1. 1 rotor winding 5
Connect the start and end of the A bearing 7 supports the end of the shaft 1 where the slip ring 6 is provided. The other end of the shaft 1 is connected to a drive engine (for example,
(not shown) is fitted and connected to the output shaft. The rotor formed as described above is rotatably provided in a stator (not shown) to constitute a salient pole field rotating alternating current generator.

[Problem to be solved by the invention]

When forming a brake winding on the salient pole rotor with the above configuration,
First, the electromagnetic steel plates on which the rotor core 2 is to be formed are stacked on the shaft 1 while positioning them one by one. Brass plates 3 are attached to both sides, and slits (not shown) are formed on the outer periphery of the four-rotor core 2. ) Insert the copper rod 4 through the hole. In this process, it is necessary to drive or push the copper rod 4 against the frictional resistance between the above-mentioned slide and the copper rod 4, which requires extremely complicated work. However, not only are there a plurality of copper rods 4, for example six or more, but they are also placed close to each other, so the above-mentioned brazing is difficult. The work also requires complicated work. For this reason, forming the brake winding requires a large number of steps.

Moreover, there is a problem that the cost is high.

On the other hand, in the field of three-phase induction motors, aluminum die casting has been commonly used as a means for forming two-rotor windings. In this case.

After sequentially laminating core materials made of electromagnetic steel sheets on the shaft, a plurality of blind holes provided on the outer periphery of the core material and plates to form both sides are formed into a cage shape using pure aluminum, and the rotor winding is performed. It is a line. However, there is a problem in that operations such as laminating the core material and press-fitting it into the shaft are extremely complicated. In addition, the rotor winding has
In order to improve efficiency, it is necessary to use high-purity aluminum, but since pure aluminum inherently has poor castability, the flow of the metal in the small diameter blind hole in the core material is poor (and the casting temperature is high). Along with having to.

There is a problem in that gas escape in the blind hole is poor, and therefore pure aluminum die-casting is also a complicated operation, making it difficult to improve the yield rate and increasing costs.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems existing in the above-mentioned prior art and to provide a salient pole field rotating alternating current generator that is easy to manufacture and has a configuration that can improve the rate of non-defective products.

[Means to solve the problem] In order to achieve the above object, one aspect of the present invention is as follows.

In a salient pole field rotating AC generator IIA having a rotor provided with a rotor winding and a brake winding, a plurality of open grooves extending in the axial direction are provided on the outer periphery of one rotor core, and inside the open grooves A rod-shaped body made of die-cast aluminum alloy is formed on the rod-shaped body, and plates made of die-cast aluminum alloy are integrally connected to both sides of the rod-shaped body to form a cage-shaped brake winding. A technical method was adopted.

In the present invention, the rod-shaped body and the plate forming the cage-shaped damping winding are made of die-cast aluminum alloy, for example, an ADC.
It is made of a material containing Cu, Si such as Io, 12, etc., which has good flowability. In this respect, it is significantly different from the conventional three-phase induction motor in which the material forming the rotor winding is made of high-purity aluminum. That is, the damper winding in the salient pole field rotating alternating current generator of the present invention is for reducing the distortion rate of the voltage waveform, and is the result of various experimental studies.

It was recognized that even if it is not necessarily made of copper or high-purity aluminum, which has extremely low electrical resistance, it can sufficiently coexist with the characteristics and performance of a portable or small salient pole field rotating alternating current generator.

[For production]

With the above configuration, the plate and the plurality of rod-shaped bodies are
! By firmly and integrally holding the rotor core made of laminated magnetic steel plates to form a cage-shaped damper winding, it is possible to exhibit the characteristics or performance required as an alternator.

〔Example〕

FIG. 1 is a partial cross-sectional explanatory view of the main parts of a rotor according to an embodiment of the present invention, and the same parts are designated by the same reference numerals as in FIG. 9. In FIG. and rod-shaped bodies, such as ADC12 (Cu, Si
The damper winding is formed into a cage-shaped damper winding by die-casting an aluminum alloy containing aluminum. That is, the first rotor core 2 is firmly held by integrally providing the brake windings on both end surfaces and part of the outer circumference of the rotor core 2 formed by laminating tM1m plates. The shaft 1 and rotor winding 5 are
After forming the cage-shaped damping winding on the rotor core 2,
Press fit and wrap each.

FIG. 2(a) is a partial cross-sectional end view showing the rotor core in FIG. 1, and FIG. 2(b) is a partial A in FIG. 2(a).
- It is a sectional front view taken along line A, and the same parts are designated by the same reference numerals as in FIG. 1. In Figures 2(a) and (b), Ia
2a is a shaft hole, 2a is an open groove, and each rotor core 2
It is provided so as to extend in the axial direction. A plurality of open grooves 2a are provided on the outer periphery of the rotor core 2, and the cross-sectional shape thereof is formed into a keyhole shape consisting of, for example, a small circle and two parallel lines.

In order to form a cage-shaped brake winding on such a rotor core 2, the rotor core 2 formed by laminating electromagnetic steel sheets is inserted into a die-casting mold (not shown) in advance, and the axial direction is After crimping 1, for example, molten metal made of ADCI2 is injected or injected.

The brake winding consisting of the plate 3a and the rod-shaped body 4a can be integrally formed. In this case, if a concave portion is previously formed on the inner surface of the die-cast mold corresponding to the rod-shaped body 4a, the rod-shaped body 4a can be
An extra portion 4b is formed on the outside of the molten metal, which is effective in promoting swirling of the molten metal and promoting degassing. In addition, the surplus part 4b
is removed by cutting after molding.

FIG. 3(a) is an end view showing the rotor core before die casting, and FIG. 3(b) is a partial B-
3(c) is an enlarged cross-sectional view taken along line C-C of the main part in FIG. 3(a), and the same parts are designated by the same reference numerals as in FIGS. 2(a) and (b). It is shown in Figure 3 (
In C), hatching is omitted for simplicity. In these figures, 2b is a V-notch, which is provided at the same corresponding position on the itM1 steel plate constituting the 1-rotor core 2.

By providing the notch 2b as described above.

By matching the notches 2b when laminating the magnetic steel sheets, the open grooves 2a of the single rotor core 2 can be aligned, and misalignment of the magnetic steel sheets can be prevented.

Next, the results of general characteristic tests and phase advance load characteristic tests performed on the alternator equipped with the rotor configured as described above will be described. As a comparative example.

The characteristics were compared using one without a damper winding and one with a damper winding consisting of a copper rod 4 and a brass plate 3 as shown in FIG.

First, in a general characteristic test, no significant difference was observed among the three in the relationship between load current and load voltage. However, a significant difference was observed in the distortion factor of the voltage waveform. In other words, in the case without a damper winding, the distortion rate increased as the load current increased, reaching a distortion rate of 19% at a rated load current of 17A and a distortion rate of 19°5% at a load current of 30A. For those with a damper winding, the distortion factor is 7.4% at a rated load current of 17A.

It was confirmed that the distortion rate remained at 10% even at a load current of 30A.

Figures 4(a) and 4(b) are diagrams showing the waveforms of the induced voltage (■) and the field applied voltage (■) at no-load and rated current load of a generator lacking a damper winding, respectively, and Figure 5 ( a) (
b) is a diagram showing the waveforms of the induced voltage vL and the field applied voltage (2) at no load and at rated current load of a generator having a damping winding, respectively. First, in FIGS. 4(a) and (b).

The waveform distortion factor of the induced voltage vL is 5% when there is no load in Fig. 4(a), but in Fig. 4(b) with the rated current 17A loaded, the waveform distortion factor of the induced voltage It becomes 19%, and the distortion of the waveform is noticeable. On the other hand, in the case of a damper having a damper winding, the waveform distortion factor of the induced voltage vL during no-load shown in Fig. 5(a) is 4.5%, and the rated current shown in Fig. 5(b) is 4.5%. Even under a load of 17 A, the waveform distortion factor of the induced voltage (2) was 7.4%, and it is recognized that the waveform has been significantly improved. It should be noted that there is no substantial difference between the damper winding formed by aluminum alloy die-casting and the conventional damper winding formed from copper and brass. We were able to demonstrate its effectiveness.

FIG. 6 is a diagram showing the relationship between load current and load voltage in the phase advance load characteristic tester. In Fig. 6, one curve a,
b and c correspond to those without a damper winding, those with a damper winding made of aluminum alloy die-casting, and those with a damper winding made of copper, respectively. As shown in Fig. 6, it is clear from curve 2 a that the damper winding is missing, but the rate of increase in load voltage with respect to increase in load current is large, and the automatic voltage The regulator was destroyed. On the other hand, as shown in curve 2 of the damper winding, as shown in c, the degree of increase in load voltage with respect to increase in load current is slow, and it is recognized that the phase advance load characteristics are excellent. . It has been found that the brake winding made of aluminum alloy die-cast according to the present invention has a phase advance load characteristic that is more uneven than that of the brake winding made of conventional copper. Ta.

FIGS. 7(a) and 7(b) each show the load current IL=9 of a generator lacking a damper winding. Induced voltage ■ and field applied voltage ■ at IA and IL = 16.5A.

Figures 8(a) and 8(b) are diagrams showing the waveforms of the induced voltage (L) and field applied voltage (2) at the load current IL-17A and IL=2OA in the embodiment of the present invention, respectively. be. As is clear from Fig. 7 (a) and (b), in the case of a device lacking a damper winding, the waveform of the induced voltage vL is large in the phase advance load characteristic test even when the load current I is less than the rated current. You can see that it is distorted. On the other hand, the waveform of the induced voltage ■L in FIGS. 8(a) and (b) is as follows.

It is clear that even when the load current IL is equal to or higher than the rated current value, the distortion factor is low and is significantly improved.

In this embodiment, a case has been described in which the three rotor is of a two-pole salient field type, but the effect is the same even if the three rotor has multiple poles of four or more poles. It goes without saying that the cross-sectional shape of the open groove to be provided in the rotor core may be other shapes than those shown in the two embodiments.

〔Effect of the invention〕

Since the present invention has the structure and operation as described above,
The following effects can be achieved.

(1) The damper winding to be provided on the rotor is easier to manufacture than the means of manufacturing it by brazing components made of copper or copper alloy.

Mass production is extremely high and costs can be reduced.

(2) Compared to the pure aluminum die-casting used in three-phase induction motors, an aluminum alloy with good castability and low cost can be used, making die-casting work easier and improving the yield rate.

(3) The distortion factor of the induced voltage waveform can be reduced, so the characteristics as an AC generator can be improved.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional explanatory view of essential parts showing a rotor in an embodiment of the present invention, and FIG. 2 (a) is a partial cross-sectional end view showing the rotor core in FIG. 1. FIG. 2 (b) is a partially sectional front view taken along the line A-A in Fig. 2(a), Fig. 3(a) is an end view showing the rotor core before die casting, Fig. 3(b)
is a partially sectional front view taken along line B-B in Fig. 3(a);
Figure (c) is an enlarged cross-sectional view taken along the line C-C of the main part in Figure 3 (a), and Figures 4 (a) and (b) are the no-load and rated values of the generator lacking a damper winding, respectively. Induced voltage at time■
, and a diagram showing the waveform of the field applied voltage vt, FIG.
) and (b) show the waveforms of induced voltage VL and field applied voltage Vf at no load and at rated current load of a generator with damper windings, respectively. Figures 7(a) and 7(b) are diagrams showing the relationship between the current and the load voltage, respectively, and the induced voltage (■) at the load current IL-9, 1A and It = 16.5A of a generator lacking a damping winding, and Figures 8(a) and 8(b), which show the waveform of the field applied voltage Vr, respectively show the load it flow I of the embodiment of the present invention.
FIG. 9 is a diagram showing the waveforms of the induced voltage V and the field applied voltage ■ when L=17A and IL=20A, and FIG. 9 is a partially cross-sectional explanatory diagram showing an example of a conventional salient pole rotor with brake Sfa. 2: Rotor core, 2a: Open groove, 3a nibrate 4a
: Rod-shaped body, 5: Rotor winding.

Claims (1)

[Claims] In a salient pole field rotating alternator having a rotor provided with a rotor winding and a brake winding, a plurality of open grooves extending in the axial direction are provided on the outer periphery of the rotor core, and A salient pole field rotation characterized in that a rod-shaped body made of die-cast aluminum alloy is formed, and plates made of die-cast aluminum alloy are integrally connected to both sides of the rod-shaped body to form a cage-shaped damping winding. type alternator.