JPS6019343Y2 - rotor of rotating electric machine - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a rotor of a rotating electric machine, and particularly to a means for joining an armature coil and a commutator constituting the rotor.

First, a conventional device of this kind will be explained using a starter motor for an internal combustion engine as shown in FIGS. 1 and 2 as an example.

In the figure, 1 is a rotating shaft, 2 is fixed to this rotating shaft 1,
An armature core 3 has a plurality of slots (not shown) formed on its outer periphery, and reference numeral 3 designates a field core 5 around which a field coil 4 is wound.
is a yoke fixed by a screw 6, 7 is a rear bracket that supports one side of the rotating shaft 1, 8 is a through bolt that fastens the front bracket (not shown), the yoke 3, and the rear bracket 7 together, and 9 is the above-mentioned A plurality of armature coils are inserted into each slot of the armature core 5 in an overlapping manner, for example, two layers of winding, and each armature coil has a protrusion 9a.

10 is a plurality of commutator pieces 11 made of copper material.
and an insulating member 12 such as a molded material that insulates and holds each commutator piece 11, and is fitted onto the rotating shaft 1.

As shown in FIG. 2, this commutator 10 has a commutator piece portion 11a, which is an extension of the commutator piece 11, in which a joint gllb is formed into which the outlet portion 9a of the armature coil 9 is inserted.
The armature coil support portion 13 is formed by the mold material portion 12a.

These, commutator 10, armature core 2, and armature coil 9
and the rotor is constructed.

A brush holder 14 is fixed to the rear bracket 7 and holds a brush 15 that is in sliding contact with the commutator piece 11;
Although not shown, 16 is an electromagnetic switch that operates to mesh the pinion gear fixed to the other side of the rotating shaft 1 with the ring gear of the engine; 17 is an electromagnetic switch that connects the commutator piece 11a and the outlet 9a of the armature coil 9; This is solder for electrical connection.

Next, the operation of the conventional device will be described. First, when starting the engine, the electromagnetic switch 16 is activated and the pinion gear is moved in the axial direction and meshes with the ring gear.

As a result, the switch section of the electromagnetic switch 16 is closed, and the field coil 4 and the brush 15 are connected to the commutator 10 by the power source.
When the armature coil 9 is energized through the rotor, rotational torque is generated in the rotor and the rotating shaft 1 is rotated, so that the ring gear is rotated via the pinion gear and the engine is started.

Here, the electrical connection between the armature coil 9 and the commutator 10 is made by aligning the eyes 9a of the armature coil 9 with the commutator piece 11.
After insertion into the bonding groove 11b of a, bonding is performed with solder 17.

However, when the armature current is applied from the power source to the armature coil 9 through the brushes 15 and the commutator 10, the rotor rotates, so that the connection between the outlet part 9a of the armature coil 9 and the commutator piece part 11a A centrifugal force generated by the rotation of the rotor acts on the armature coil 9, and the armature coil 9 tends to pop out.

At the same time, the Joule heat generated by energizing the armature rectifier,
Frictional heat generated between the brush 15 and the commutator piece 11, as well as synergistic heat such as high heat from the engine, affects the joint, making it possible to melt the solder 17.

Therefore, due to the low bonding strength itself due to soldering and the above-mentioned conditions, the bonding strength between the outlet 9a of the armature coil 9 and the commutator piece 11 at the bonded portion decreases significantly, and eventually the wire breaks. It may cause an accident and cease to function as a starting motor.

This is particularly noticeable in engines where the rotor is rotated at high speed by increasing the armature current for the purpose of improving engine startability or the like.

In order to eliminate this problem, the commutator piece portion 11a1, that is,
It is conceivable to increase the joint strength by increasing the radial dimension of the armature coil support part 13 and deepening the joint groove 11b, but since the support part 13 becomes large, the copper material forming the commutator piece 11, A large amount of molding material and solder 17 are required, resulting in an expensive device and a large diameter.

This invention, of course, eliminates each of the above drawbacks, but
By joining one of the outlet portions of the two armature coils to the commutator piece using a hard soldering method that is superior to soldering, the radial dimension of the commutator piece can be shortened, and the two The present invention provides a rotor for a rotating electric machine whose purpose is to greatly improve the bonding strength between one of the outlet portions of an armature coil and a commutator piece portion.

The embodiment shown in FIGS. 3 to 5 will be described below.

In the figure, llc is a commutator piece portion which extends shortly in the radial direction of the commutator piece 11, that is, has a shortened radial dimension as shown in FIG. have.

lld is a joining groove formed at the radial end of this commutator piece portion 11c, the depth of which is shallow, and the sunrise portion 9 of the armature coil
It is shallower than the thickness of one side of a.

This joint 111d is not one in which the outlet portion 9a of the armature coil 9 in the conventional device is inserted, but is used to maintain the bonding position between the commutator piece 11 and the outlet portion 9a of the armature coil 9.

Note that the radial dimension of the armature coil support portion 13 is shortened due to the shortening of the commutator piece portion 11c.

18 is a welded portion formed by radially overlapping each outlet portion 9a of two armature coils 9 and welding by TIG method;
Reference numeral 19 denotes a hard brazing material used to join one of the above-mentioned outlet portions 9a and the radial end portion of the commutator piece portion 11c, and this joining is performed by a hard soldering method.

The operation of the device constructed in this way is the same as that of the conventional device, so the explanation will be omitted.
The connection with 1 will be explained.

First, the outlet portion 9a of each armature coil 9 is subjected to the TIG method, that is,
A tungsten electrode is placed opposite the other protrusion 9a with a predetermined gap, and the contact portions of each protrusion 9a are melted and welded by arc discharge generated in the gap (this welding state is (shown in figure).

In this state, the commutator 10 is inserted into the rotating shaft 1, and the joining groove 11d of the commutator piece portion 11C contacts one of the outlet portions 9a of the armature coil 9 with a certain pressure. move to position.

Thus, in a state where the commutator piece portion 11c and one sunrise portion 9a of the armature coil 9 are in sufficient contact and the contact resistance is small, the sunrise portion 9a and the commutator piece portion 11c are in contact with each other. A brazing material 19 such as phosphor-copper solder is inserted into the joint, and positive and negative electrodes made of carbon or the like are brought into contact with the other sunrise part 9a and commutator piece part 11a, respectively.

In this state, if a predetermined voltage from a power source (not shown) is applied between each electrode and a large current is passed through the positive and negative electrodes to the outlet part 9a and the commutator piece part 11c, Joule heat ( The joint between the eyelet 9a and the commutator piece 11c is heated by approximately 800 to 850 degrees Celsius, and this high heat melts the brazing filler metal 19 and fills the gap between the joints, thereby forming the eyelet. 9a and commutator piece portion 11c are joined.

(The joining state is shown in FIG. 5.) This joining means is what is called a resistance brazing method using a hard soldering material.

In this way, if the sunrise part 9a and the commutator piece 11 are joined by the resistance brazing method, the high heat for the joining is generated only in the joint part, and the molding material 1 holding the commutator piece is heated.
It is not conducted and has no effect on the entirety of 2.

This applies to joints and brazing material 19, such as gas welding, for example.
If a heat source that heats a wide area to a high temperature is used, the entire armature coil 9 and commutator 10 will be heated to a high temperature due to the high heat, the enamel of the armature coil 9 will be peeled off, and the commutator 10 will be damaged. The mold material 12 thermally expands and the commutator piece 1
1 will float up and lose its function as a commutator.

On the other hand, the high heat generated in the brazing method does not melt the welded portions of the armature coils 9 to the outlet portions 9a and separate the outlet portions 9a.

This is because high heat is not generated in the welded portion of each outlet portion 9a.

Furthermore, the synergistic heat such as frictional heat between the brush 15 and commutator piece 11 that affects the joint, Joule heat due to armature current, and high heat from the engine is at a temperature that melts the solder. It has not yet reached the point where the brazing filler metal 19 in the part is melted, and even if the centrifugal force of the rotor acts, the joint strength between the joint part, that is, the eyelet part 9a and the commutator piece 11c, is sufficiently ensured and there is no possibility of wire breakage. There will be none.

Furthermore, the sunrise part 9a is connected to the commutator piece part 11 by soldering.
Since the joint is connected to the armature coil support part 13, the strength of the joint can be greatly improved compared to soldering.
That is, the radial dimension of the commutator piece portion 11C1 and the molded material portion 12b can be shortened, the commutator 10 can be made smaller, and the amount of copper and molding material in the commutator piece portion 11c can be reduced. No. 10 can be manufactured easily and inexpensively.

Incidentally, in the above embodiment, a description has been given of an electric motor, but the same effect can be achieved in a commutator of a generator.

[Brief explanation of the drawing]

Fig. 1 is a structural diagram showing a conventional starting motor, Fig. 2 is a partial front view of the commutator 10 in the device shown in Fig. 1, and Fig. 3 is a partial front view of the commutator 10 showing an embodiment of the invention. Figure 4 shows the outlet 9 of each armature coil 9 in the device shown in Figure 3.
FIG. 5 is a side view showing a state in which the sunrise part 9a and commutator piece part 11c in the apparatus shown in FIG. 3 are joined. In the figure, 1 is the rotating shaft, 2 is the rotor core, 4 is the field coil, 5 is the field core, 9 is the armature coil, 9a is the outlet,
10 is a commutator, 11 is a commutator piece, 11a, llc are rectifier pieces, llb, lld are joint grooves, 12 is a molding material, 12
Reference numerals a and 12b designate molding material parts, 13 an armature coil support part, 15 a brush, 17 solder, 18 a welding part, and 19 a hard brazing material. The same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A commutator piece portion having a radial end portion that extends short in the radial direction and is integrally formed with the commutator piece constituting the commutator and has a positioning joint groove formed at the radial end, and a commutator piece portion that overlaps each other in the radial direction. and are joined by welding means, and one of the overlapping armature coils is installed in the positioning joint groove and joined by hard soldering, and the positioning joint A rotor for a rotating electric machine, wherein the groove is formed to be shallower than the radial dimension of one sunrise portion of the armature coil.