JPS6364145B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a brush in a DC rotating machine such as a DC motor or a DC generator, which is provided with multi-wave windings.

Generally, a winding specification in which a plurality of independent circuits are formed throughout the formed coil is called multi-winding, and the number of independent circuits is called multiplicity. Now, if the multiplicity of a DC rotating machine with multi-wave winding is m, then usually a pair of brushes that can slide into at least m adjacent commutator segments at the same time are arranged. There is. However, as shown in FIG. 1, with such a brush, due to factors such as the clearance between the brush 1 and the brush holder 2, the gouging between the commutator 3 and the brush 1, and unbalanced loads, the brush 1 is not connected to the commutator. It was not uncommon for the ball to come into contact with the ball on one side. In addition, since the brush 1 is essentially a so-called point contact in which only the protrusions of brush particles such as carbon on the sliding contact surface are in contact with the commutator surface, the above-mentioned factors of uneven sliding contact are further exacerbated. There was a tendency to When this kind of one-sided sliding contact occurs, a so-called dead coil occurs, where the multiple circuits configured in the coil are not electrically connected.
This caused the problem that the output characteristics of the DC rotating machine changed and the efficiency decreased.

The present invention has been made in view of the above points, and by improving the configuration of the brush, multiple circuits configured in the coil can always be stably and efficiently conducted, and stable output characteristics can be exhibited. The purpose is to provide DC rotating machines. The present invention is characterized by having a rotor formed by appropriately connecting coils having a plurality of independent circuits to a large number of segments provided in a commutator, and a DC rotating machine having brushes in sliding contact with the segments. wherein the number of brushes is twice as many as the number of independent circuits, and the width of the surface of each brush in sliding contact with the segment is equal to or less than the width of the segment in the sliding direction. be.

Next, specific embodiments of the present invention will be described based on the attached drawings. FIG. 2 is a plan view showing the main parts inside the DC rotating machine according to the present invention. In FIG. 2, reference numeral 4 denotes a rotating shaft of a rotor, and a cylindrical commutator 5 and a disc-shaped rotor core 6 are mounted on the rotating shaft 4 in close proximity and in parallel. A total of 26 winding grooves 6a are formed in the rotor core 6 in two stages with 13 winding grooves in each stage. or,
The same number of segments 5a as the winding grooves 6a are evenly arranged on the entire circumferential surface of the commutator 5. Further, each segment 5a is provided with a riser portion (not shown) for locking a conductive wire. As will be described later, a well-known wave winding method is used to form a coil in each stage of the two-stage winding groove 6a formed in the rotor core 6, and a so-called multiple winding in which each stage has an independent circuit. For example, a double-wound coil 7 is formed as in this example.

According to the present invention, since the multiplicity of the coils is twofold, the four brushes 8a to 8d are arranged in such a manner that their tips abut against the segments 5a provided on the circumferential side of the commutator 4. has been done.
The width in the sliding direction of the sliding surface of each brush with the commutator is approximately equal to or slightly smaller than the width in the sliding direction of one segment. The arrangement positions of the four brushes 8a to 8d are determined as follows.

If the total number of segments of the commutator is c, the number of field pole pairs of the stator is p, and the total number of poles is 2p, then the appropriate segment pitch for brush arrangement is s.
is obtained by s=k・c/2p (k is a natural number)...Equation (1). Therefore, in this example, the total number of segments c is 26, and the total number of field poles 2p is 6, so the minimum unit of the appropriate segment pitch s is given by equation (1).
4.33... However, this segment pitch is
represents the spacing between the center lines of each brush. Therefore, in this example, the brush 8a is brought into contact with the center of the segment 4', and the next brush 8b is applied to the segment 8', where about 4.3 segments are placed, until the segment 9' is close to the segment 9'. Align the center line with the remaining point and touch it. Therefore, this brush 8b comes into contact with the two continuous segments 8', 9' while straddling them. The subsequent brushes 8c and 8d are also sequentially arranged clockwise at the same intervals as above, and have segments 12' to 13' and segment 17', respectively.
is in contact with.

The arrangement position of each brush is not limited to the position of this example, and various arrangements are possible by applying an arbitrary natural number to k in the above equation (1). For example, as shown in FIG. 3 as another embodiment, a distance of 8.6 commutators is secured from brush 8'a to the next brush 8'b when k=2, and from brush 8'a to the next brush 8'c. is brush 8'a to k=
It is also possible to secure an interval of 13.0 pieces of k=5 from brush 8'a to the last brush 8'd.

If the brushes 8a and 8'a are positive, the polarity of the individual brushes arranged at the positions determined in this way is as follows: If the brushes 8a and 8'a are positive, The negative electrode is used as the negative electrode, and the brushes arranged in even-numbered positions are used as the positive electrode.
It suffices if they have the same polarity.

Next, the winding circuit of the double-wave winding coil formed in the above embodiment will be explained in detail based on a schematic development view of the main part of FIG. 4. In FIG. 4, reference numeral 6b denotes an end face of a branch-shaped peripheral portion of the rotor core 6, which branches into 26 branches to form 26 winding grooves. These 26 branches are numbered in clockwise order to differentiate them. Further, 5a indicates 26 segments, which are similarly numbered in clockwise order to distinguish them. The two-stage winding groove 6a also has a deep groove a,
Shallow grooves are designated b and numbered in clockwise order. Therefore, for example, a shallow groove _b1 is formed between branch parts 1 and 2, and a deep groove _a2 is formed between branch parts 2 and 3. Here, the broken lines represent winding circuits wound in deep grooves, and the solid lines represent winding circuits wound in shallow grooves.

In this example, a unique winding circuit is constructed for each stage using the wave winding method. That is, in deep stage a, segment 4' → groove a ₆
→ Groove a ₁₀ → In the path of segment 12', one coil is formed by repeating winding several times between groove a ₆ and groove a ₁₀ , and then connected to segment 12', and then placing groove a ₁₂ . The winding is repeated again between groove a ₁₄ and groove a ₁₈ to connect the segment 20'. By repeating this winding operation in a fixed direction around the circumference where the deep groove a is formed, 13 coils are finally formed evenly in this stage, and then the segment 4' Returning to , one independent winding circuit is constructed. If a coil is similarly formed in the shallow groove b by the wave winding method, an independent circuit as shown by the solid line will be constructed. Here, the odd-numbered segments 5a are used for the winding circuit of the shallow groove b, and the even-numbered segments 5a are used for the winding circuit of the deep groove a. That is, different independent circuits are connected alternately to every other segment 5a.

For the winding circuit configured as described above, the arrangement of the brushes in the two embodiments shown in FIG. 2 and FIG. shown.

Next, the current conduction effect in the DC rotating machine of the above embodiment will be explained based on FIG. 4. In the embodiment in which the brushes are arranged as shown in FIG.
From 3', groove b ₁₅ → groove b ₁₉ → groove b ₂₃ → groove b ₁ → groove b ₅ → groove
b ₉ → Groove b ₁₃ → Groove b ₁₇ → Groove b ₂₁ → Groove b ₂₅ → Groove b ₃ → Groove b ₇ It reaches the segment 9' where the brush 8b on one side comes into contact, so from the + side Current is conducted to the side. Furthermore, the other circuit branching from segment 13' is also connected to the groove b ₁₁ →b ₇ →b ₃ →b ₂₅ →b ₂₁ →b ₁₇
→b ₁₃ →b ₉ →b ₅ →b ₁ →b ₂₃ →b ₁₉ leads to the segment 17' where the brush 8d on one side comes into contact,
Current is conducted. Therefore, in the circuit of the coil formed in the shallow outer winding groove, that is, the circuit shown by the solid line in FIG.
Only the path b ₁₅ → groove b ₁₁ . In addition, in a coil circuit formed in a deep winding groove, from the segment 4' where the + side brush 8a comes into contact, a ₂ →
a ₂₄ →a ₂₀ →a ₁₆ →a ₁₂ →a ₈ →a ₄ →a ₂₆ →a ₂₂ →a ₁₈ →a ₁₄
→a ₁₀ , the current is conducted to the segment 8' where the brush 8c on one side comes into contact. However, the other branch circuit passes through groove a ₆ → groove a ₁₀ and connects to segment 12', which brush 8c on the + side comes into contact with.
Therefore, no current is conducted through this path. However, the other circuit branching from this segment 12' is the groove a ₁₄ →a ₁₈ →a 22 →a ₂₆ → _{a 4 →} a ₈ →
The current is conducted through a ₁₂ →a ₁₆ →a ₂₀ →a ₂₄ →a ₂ →a ₆ and reaches the segment 8' where the segment 8b on one side comes into contact. As described above, in this example, the proportion of so-called dead coils generated in non-conducting coils is always small, and efficient and stable output characteristics can be obtained. Also, even in the embodiment in which the brushes are arranged as shown, the dead coil is the groove.
There are only the paths b ₁₉ → groove b ₂₃ and the path a ₆ → groove a ₁₀ , and the coil can be electrically conductive efficiently as in the previous embodiment.

As described in detail above, according to the present invention, the width of the brush of a DC rotating machine equipped with multi-wave winding is formed to be smaller than the width of the segment, thereby dividing the brush into smaller pieces, so that the brush can be placed in the commutator. This prevents contact between the wires and the winding circuit, and the winding circuit can always be conducted efficiently. Therefore, the output characteristics of the DC rotating machine are stable and the efficiency does not decrease. It should be noted that the present invention should not be limited to the above-mentioned specific examples,
Of course, various modifications are possible within the technical scope of the present invention. For example, the formed coils may be formed in one stage or in multiple stages of three or more stages, and the independent circuits can be configured in various specifications accordingly.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view of the main parts of a conventional DC rotating machine with multiple windings, and FIG. 2 is a schematic plan view of the main parts of an embodiment of the DC rotating machine according to the present invention.
FIG. 3 is a schematic plan view of essential parts showing another embodiment of the DC rotating machine according to the present invention, and FIG. 4 shows the arrangement of the winding circuit and brushes of the two embodiments of the DC rotating machine according to the present invention. It is a schematic development diagram of the main part. Explanation of symbols, 1, 8a, 8b, 8c, 8d,
8'a, 8'b, 8'c, 8'd: Brush, 3, 5:
Commutator, 3a, 5a: Segment.

Claims (1)

[Claims] 1. A DC rotating machine having a rotor formed by appropriately connecting coils having a plurality of independent circuits to a large number of segments provided on a commutator, and brushes in sliding contact with the segments,
A direct current having twice as many brushes as the number of independent circuits, and a width of a surface of each brush in sliding contact with the segment is equal to or less than a width of the segment in the sliding direction. Rotating machine.