CN110137762B - Commutator and brush motor with same - Google Patents
Commutator and brush motor with same Download PDFInfo
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- CN110137762B CN110137762B CN201811207140.0A CN201811207140A CN110137762B CN 110137762 B CN110137762 B CN 110137762B CN 201811207140 A CN201811207140 A CN 201811207140A CN 110137762 B CN110137762 B CN 110137762B
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- commutator
- insulating base
- peripheral surface
- projection
- gap
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R39/00—Rotary current collectors, distributors or interrupters
- H01R39/02—Details for dynamo electric machines
- H01R39/04—Commutators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K23/00—DC commutator motors or generators having mechanical commutator; Universal AC/DC commutator motors
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Abstract
The invention makes the groove of the insulation base station for accumulating the abrasion powder not easy to play a role. The present invention has: an insulating base (47) having a circular cross-sectional shape on the outer peripheral surface; and commutator segments (49) which are arranged on the outer peripheral surface (47a) of the insulating base platform with a gap (49e) therebetween in the circumferential direction. The commutator segment (49) has an arc portion (49a) and a terminal portion (49 d). The arc portion (49a) has an outer peripheral surface (49b) in sliding contact with the brush (33), and an inner peripheral surface (49c) in contact with the outer peripheral surface (47a) of the insulating base (47). The insulating base (47) has a groove (47b) at a position corresponding to the gap (49 e). A projection (48a) is formed in the recessed groove (47b) so as to stand from the inside to the outside in the radial direction. The protrusion (48a) is formed along the gap (49e) in a state of not contacting the commutator segment. The tip of the projection (48a) is located radially inward of the outer peripheral surface (49b) of the arcuate portion.
Description
Technical Field
The invention relates to a small-sized direct current motor with a brush, in particular to a commutator of the small-sized direct current motor.
Background
As a commutator for a small-sized brush-equipped dc motor, for example, there is a commutator in which a plurality of commutator segments divided in the circumferential direction are arranged on the outer peripheral surface of a cylindrical insulating base with a predetermined gap therebetween, and a groove having the same width as the gap is formed on the insulating base so as to face the gap. However, when such a small-sized dc motor is rotated for a predetermined period of time, abrasion powder generated by sliding friction between the commutator and the brush is accumulated in the grooves between the commutator segments, which causes a problem of short-circuiting between the commutator segments.
In order to solve this problem, for example, patent document 1 describes a cylindrical commutator having a 1 st groove wider than a gap between commutator segments and a 2 nd groove narrower than the 1 st groove in a groove wider than the gap, the 2 nd groove being disposed at a position corresponding to the gap, and the 1 st groove and the 2 nd groove being disposed adjacent to each other. According to this cylindrical commutator, the arc generated when the brush passes through the gap between the commutator segments hardly reaches the inner wall surface of the 1 st groove, and carbonization of the insulating base due to the heat of the arc is prevented, so that even when abrasion powder enters the groove, the abrasion powder can be smoothly discharged, and the abrasion powder is hardly accumulated.
Patent document
Patent document 1 Japanese patent laid-open publication No. Sho 58-212347
Disclosure of Invention
Problems to be solved by the invention
However, in the above-described structure, when the commutator is continuously rotated in one direction, abrasion powder tends to be unevenly accumulated in the grooves on the opposite side to the direction of rotation of the commutator. As a result, although there is a sufficient space in the groove located on the rotation direction side of the commutator, the commutator segments are short-circuited by abrasion powder, and the groove of the insulating base may not function sufficiently.
Accordingly, the present invention provides a commutator capable of improving the life of a motor, and a brush motor having the commutator.
Means for solving the problems
The following describes embodiments of the present invention that have been made to solve the above problems. The embodiments and technical features of the present invention are not limited to the following description, and can be understood as the contents described in the entire specification and drawings or as an idea of the invention that can be thought of by those skilled in the art based on the descriptions.
The 1 st commutator of the invention has: an insulating base having a circular cross-sectional shape on the outer peripheral surface; and a plurality of commutator segments arranged on an outer peripheral surface of the insulating base with a gap therebetween in a circumferential direction,
the commutator segment has an arc portion and a terminal portion,
the arc portion has an outer peripheral surface in sliding contact with the brush and an inner peripheral surface in contact with the outer peripheral surface of the insulating base,
the insulating base has a groove at a position corresponding to the gap,
a projection part from the inner side to the radial outer side is vertically arranged on the groove,
the protrusion is formed along the gap in a state of not contacting the commutator segment,
the tip of the projection is located radially inward of the outer peripheral surface of the arc portion.
The 2 nd commutator of the invention has: an insulating base having a circular cross-sectional shape on the outer peripheral surface; and a plurality of commutator segments arranged on an outer peripheral surface of the insulating base with a gap therebetween in a circumferential direction,
the commutator segment has an arc portion and a terminal portion,
the arc portion has an outer peripheral surface in sliding contact with the brush and an inner peripheral surface in contact with the outer peripheral surface of the insulating base,
a projection portion is vertically provided on the insulating base from the outer peripheral surface toward the radial outer side,
the protrusion is formed along the gap in a state of not contacting the commutator segment,
the tip of the projection is located radially inward of the outer peripheral surface of the arc portion.
The 3 rd commutator of the present invention has: a flat insulating base; and a plurality of commutator segments arranged on one surface of the insulating base with a gap therebetween in a circumferential direction,
the commutator segment has a contact portion and a terminal portion which are in sliding contact with the brush,
the insulating base has a groove at a position corresponding to the gap,
a protrusion portion standing from the inner side to the outer side is formed in the groove,
the protrusion is formed along the gap in a state of not contacting the commutator segment,
the tip of the protrusion is located inward of the outer surface of the contact portion.
The 4 th commutator of the invention has: a flat insulating base; and a plurality of commutator segments arranged on one surface of the insulating base with a gap therebetween in a circumferential direction,
the commutator segment has a contact portion in sliding contact with the brush and a terminal portion,
a protrusion is formed on one surface of the insulating base,
the protrusion is formed along the gap in a state of not contacting the commutator segment,
the tip of the protrusion is located inward of the outer surface of the contact portion.
The brush motor of the present invention is characterized in that the brush motor has the commutator.
Effects of the invention
In the commutator of 1 st, the protrusion is formed along the gap in a state of not contacting the commutator segment, and thus the abrasion powder entering the groove is divided in the circumferential direction by the protrusion, and the abrasion powder is less likely to accumulate in one of the grooves unevenly. As a result, short-circuiting between segments of the commutator due to abrasion powder can be prevented in a state where there is a sufficient space in the recess on the rotation direction side of the commutator. Therefore, compared with the structure as in the conventional example, the space in the concave groove can be effectively used, the time for short-circuiting between the commutator segments due to abrasion powder can be extended, and the service life can be extended.
In addition, in the 2 nd commutator, since the projection is formed along the gap without contacting the commutator segment, the abrasion powder entering the gap is divided in the circumferential direction by the projection, and the abrasion powder is less likely to be unevenly accumulated in one of the gaps. Therefore, the present invention can slightly extend the time until short-circuiting between segments due to abrasion powder, and thus extend the lifetime, as compared with a commutator in which the outer peripheral surface has a circular cross-sectional shape and segments are circumferentially arranged on an insulating base having no projection formed on the outer peripheral surface.
Further, in the 3 rd commutator, the projection is formed along the gap in a state of not contacting the commutator segment, and therefore the abrasion powder entering the groove is divided in the circumferential direction by the projection, and the abrasion powder is less likely to accumulate unevenly in one of the grooves. As a result, short-circuiting between segments of the commutator due to abrasion powder can be prevented in a state where there is a sufficient space in the recess on the rotation direction side of the commutator. Therefore, compared with the structure as in the conventional example, the space in the concave groove can be effectively used, the time until short circuit between the commutator segments due to abrasion powder is prolonged, and the service life is prolonged.
In the 4 th commutator, the projections are formed along the gaps without contacting the commutator segments, and therefore the abrasion powder entering the gaps is divided in the circumferential direction by the projections, and the abrasion powder is less likely to accumulate unevenly in one of the gaps. Therefore, the present invention can slightly extend the time until short-circuiting between commutator segments due to abrasion powder and prolong the service life, as compared with a commutator in which commutator segments are arranged in a flat insulating base having no projection formed on the outer surface thereof in the circumferential direction.
Further, the brush motor having the commutator described above can have an extended life.
Drawings
Fig. 1 is a sectional view schematically showing a brush motor according to embodiment 1 of the present invention.
Fig. 2 shows the commutator 46 shown in fig. 1, where (a) is a partial plan view of the arrow a-a and (B) is a front view of the arrow B-B.
Fig. 3 is a partially enlarged view of arrows C-C of fig. 2 (a).
Fig. 4 is a partially enlarged view of a commutator in embodiment 2 of the present invention.
Fig. 5 is a partially enlarged view of a commutator in embodiment 3 of the present invention.
Fig. 6 is a partially enlarged view of a commutator according to embodiment 4 of the present invention.
Fig. 7 is a sectional view schematically showing a brush motor according to embodiment 5 of the present invention.
Fig. 8 shows the commutator 146 shown in fig. 7, in which (a) is a partial plan view of arrows D-D, and (b) is a front view of arrows E-E.
Fig. 9 is a partially enlarged view of arrows F-F of fig. 8 (b).
Fig. 10 is a partially enlarged view of a commutator according to embodiment 6 of the present invention.
Fig. 11 is a partially enlarged view of a commutator according to embodiment 7 of the present invention.
Fig. 12 is a partially enlarged view of a commutator according to embodiment 8 of the present invention.
Fig. 13 is a partially enlarged view of a commutator according to modification 1 of the present invention.
Fig. 14 is a front view of a commutator according to modification 2 of the present invention.
Fig. 15 is a partially enlarged view of a commutator according to modification 3A of the present invention.
Fig. 16 is a partially enlarged view of a commutator according to modification 3B of the present invention.
Fig. 17 is a front view of a commutator according to modification 4A of the present invention.
Fig. 18 is a partially enlarged view of a commutator according to modification 5 of the present invention.
Fig. 19 is a partial plan view of a commutator according to modification 6 of the present invention.
Fig. 20 is a partially enlarged view of a commutator according to modification 7A of the present invention.
Fig. 21 is a partially enlarged view of a commutator according to modification 7B of the present invention.
Fig. 22 is a partial plan view of a commutator according to modification 8A of the present invention.
Description of the reference symbols
1a brush motor; 10 a shell; 20 a housing; 21a cylindrical portion; 21b a base plate; 22 a radial bearing; 30 brackets; 31 a recess; 32 a radial bearing; 33 brushes; 33a contact portion; a 33b terminal; 40 rotors; 41 a rotating shaft; 42 an armature core; 43 copper wire; 46 a commutator; 47 insulating base station; 47a an outer peripheral surface of the insulating base; 47b groove of insulating base; 47b1 bottom surface of groove of insulating base station; 47b2 side surface of groove of insulating base station; 48a protrusions of the insulating base; 49a commutator segment; 49a circular arc portion; 49b the outer peripheral surface of the arc portion; 49c an inner peripheral surface of the arc portion; 49d terminal portion; 49e gap.
Detailed Description
In the present specification, a direction parallel to the rotary shaft 41 in fig. 1 and 7 is referred to as an "axial direction", a radial direction about the rotary shaft 41 is simply referred to as a "radial direction", and a rotational direction of the rotary shaft 41 is referred to as a "circumferential direction".
In addition, the up-down direction does not indicate a positional relationship or a direction when actually mounted in the apparatus.
Embodiments of the present invention are described below by way of example with reference to the accompanying drawings.
(embodiment 1)
Fig. 1 is a sectional view of a brush motor 1 of this example. As shown in fig. 1, the brush motor 1 includes a housing 10 having a stator 34 mounted on an inner peripheral surface thereof, and a rotor 40 disposed inside the housing 10.
The housing 10 has: a housing 20 formed in a bottomed hollow cylindrical shape from a metal material; the bracket 30 is fitted into the opening of the housing 20 and also serves as a bearing housing made of a metal material such as resin.
The housing 20 is composed of a cylindrical portion 21a and a bottom plate 21b, and a radial bearing 22 is press-fitted into a central portion of the bottom plate 21 b.
A circular recess 31 is formed in the center of the bracket 30, and the bottom surface of the recess 31 serves as a thrust bearing. The radial bearing 32 is press-fitted into the recess 31.
The stator 34 is fixedly bonded to the inner circumferential surface of the cylindrical portion 21a, and is composed of a cylindrical permanent magnet in which N and S poles are alternately magnetically attracted along the circumferential direction.
The rotor 40 has: a rotating shaft 41; an armature core 42 attached to the rotating shaft 41 and formed by stacking a plurality of thin steel plates; a copper wire 43 wound in a coil shape around the armature core 42; and a commutator 46 electrically connected to the copper wire 43.
The rotor 40 rotatably supports a rotary shaft 41 via radial bearings 22 and 32. One end of the rotary shaft 41 protrudes from the housing 10, and the other end of the rotary shaft 41 is supported by a thrust bearing.
The bracket 30 is provided with a brush 33, and the brush 33 is in sliding contact with the commutator 46 at a predetermined pressure to flow a current. In fig. 2, two brushes 33 are provided in point symmetry about the rotating shaft 41. The brush 33 has a fork-like distal end divided from the distal end, and has a flat contact portion 33a that contacts the commutator 46. The contact portion 33a is formed in a square shape as shown by a broken line in fig. 2(b), and the axial distance of the contact portion 33a is formed shorter than the distance from the upper end to the lower end of an arc portion 49a of a commutator segment, which will be described later. The distance in the direction perpendicular to the axial direction of the contact portion 33a is formed longer than the width of a gap 49e of a commutator segment, which will be described later. The contact portion 33a can simultaneously make sliding contact with the adjacent commutator segment 49.
The commutator 46, which is a feature of the present invention, will be described with reference to fig. 2 or 3 in particular.
The commutator 46 has an insulating base 47 and three commutator segments 49.
The insulating base 47 is molded using a thermoplastic resin. The outer peripheral surface 47a of the insulating base has a circular cross-sectional shape in a cross-sectional view perpendicular to the axial direction shown in fig. 2 (a).
The commutator segment 49 is made of a conductor, and has an arc portion 49a having a C-shaped cross section along the outer peripheral surface 47a of the insulating base, and a terminal portion 49d electrically connected to the tip end of the copper wire 43.
The arc portions 49a of the three commutator segments are arranged to surround the insulating base 47 in the circumferential direction to form a cylindrical shape, with a gap 49e therebetween. The arcuate portion 49a has a radially outer peripheral surface 49b in sliding contact with the contact portion 33a of the brush, and a radially inner peripheral surface 49c in contact with the outer peripheral surface 47a of the insulating base. The outer peripheral surface 49b of the arcuate portion is disposed concentrically with the outer peripheral surface 47a of the insulating base. Specifically, the center of curvature of the outer peripheral surface 49b of the circular arc portion is located on the center line of the rotary shaft 41. The commutator segment 49 is also called a cylindrical type because the commutator segment 49 in sliding contact with the contact portion 33a of the brush is disposed in a cylindrical shape around the rotation shaft.
As shown in fig. 2(b), the gaps 49e between adjacent segments are formed continuously from the upper end to the lower end of the arcuate portion 49a in parallel with the axial direction and with the same width.
A groove 47b is formed in the insulating base 47 at a position corresponding to the gap 49e between adjacent commutators. In fig. 2(b), the groove 47b is continuously formed along the gap 49e from the upper end to the lower end of the circular arc portion 49a with the same width. In fig. 3, the groove 47b is formed to open radially outward, and has a bottom surface 47b1 having a width larger than that of the gap 49e and a side surface 47b2 having a predetermined depth. The concave groove 47b is formed through the center of the gap 49e in the circumferential direction and is formed in line symmetry with respect to a line 51 perpendicular to the axis of the rotary shaft 41.
Further, a projection 48a (or a projection bar) is integrally provided so as to stand radially outward from the inside of the concave groove 47 b. The projection 48a is disposed at a position corresponding to (or facing) the gap 49 e. That is, in fig. 2(b), the projection 48a is formed continuously along the gap 49e from the upper end (one end) to the lower end (the other end) of the arc portion 49a in the same shape.
The projection 48a is erected at the center of the gap 49e in the circumferential direction. Specifically, the protrusion 48a is formed so as to pass through the center of the gap 49e in the circumferential direction and be line-symmetrical with respect to a line 51 perpendicular to the axis of the rotary shaft 41.
The cross-sectional shape of the projection 48a is a triangular shape that divides the abrasion powder in the circumferential direction in this example. The cross-sectional shape of the projection 48a may be appropriately selected from a trapezoidal shape, a rectangular shape, and the like, as long as it is suitable for dividing abrasion powder in the circumferential direction. Unless otherwise specified, the abrasion powder of the present invention includes mechanical abrasion powder generated due to sliding frictional resistance of the brush and the commutator segment, and electrical abrasion powder generated due to sparks at the time of switching of the commutator segment and the like.
The protrusion 48a is formed so as not to contact the adjacent arc portion 49a, and at least the tip end of the protrusion 48a is completely visible from the gap 49e when viewed from the radially outer side.
The tip of the projection 48a is formed radially inward of the outer peripheral surface 49b of the arcuate portion so as not to project radially outward of the outer peripheral surface 49b of the arcuate portion. That is, the radius from the center of the rotating shaft 41 to the tip of the protrusion 48a is smaller than the radius from the center of the rotating shaft 41 to the outer peripheral surface 49b of the circular arc portion.
In order to prevent the projection 48a of the single insulating base 47 from being deformed by an external force when the motor is assembled, the distal end of the projection 48a is formed radially inward of the outer peripheral surface 47a of the insulating base 47. That is, the radius from the center of the rotary shaft 41 to the tip of the projection 48a is smaller than the radius from the center of the rotary shaft 41 to the outer peripheral surface 47a of the insulating base 47. That is, the distal end of the projection 48a is formed radially inward of the inner peripheral surface 49c of the arcuate portion.
Thus, the commutator 46 of the present example has: an insulating base 47 having a circular cross-sectional shape on the outer peripheral surface; and three commutator segments 49 arranged on the outer peripheral surface 47a of the insulating base with a gap 49e therebetween in the circumferential direction.
The commutator segment 49 has an arc portion 49a and a terminal portion 49 d.
The arcuate portion 49a has an outer peripheral surface 49b in sliding contact with the brush 33, and an inner peripheral surface 49c in contact with the outer peripheral surface 47a of the insulating base 47.
The insulating base 47 has a groove 47b at a position corresponding to the gap 49 e.
A projection 48a is formed in the concave groove 47b to stand from the inner side to the outer side in the radial direction.
The projection 48a is continuously formed along the gap 49e without contacting the commutator segment 49.
The distal end of the projection 48a is located radially inward of the outer peripheral surface 49b of the arcuate portion.
In this way, the protrusion is continuously formed along the gap in a state of not contacting the commutator segment, and therefore the abrasion powder entering the groove is divided in the circumferential direction by the protrusion, and the abrasion powder is less likely to accumulate unevenly in one of the grooves. As a result, short-circuiting between segments of the commutator due to abrasion powder can be prevented in a state where there is a sufficient space in the recess on the rotation direction side of the commutator.
Therefore, the space in the recessed groove can be effectively used as compared with the conventional example, the time for short-circuiting between commutator segments due to abrasion powder can be extended, and the service life can be extended.
Further, since the distal end of the projection 48a of the insulating base projects from the outer peripheral surface 47a of the insulating base, there is a possibility that the projection of the single insulating base is deformed by an external force when the motor is assembled.
On the other hand, when the distal end of the projection 48a is formed radially inward of the outer peripheral surface 47a of the insulating base, the projection of the insulating base of a single product is not deformed by an external force at the time of assembling the motor, and the quality at the time of assembling the motor is improved.
Further, since the projection 48a is erected at the center in the circumferential direction of the gap 49e, the abrasion powder entering the groove 47b is easily equally divided in the circumferential direction by the projection, and is not easily biased to one side in the rotational direction of the groove, and the space in the groove is easily and effectively used.
(embodiment 2)
A commutator for a brush motor according to embodiment 2 of the present invention will be described with reference to fig. 4. In fig. 4, the same components as those in fig. 1 to 3 are denoted by the same reference numerals, and redundant portions will not be described.
In embodiment 1, the distal end of the projection 48a is located radially inward of the outer peripheral surface 47a of the insulating base. On the other hand, in embodiment 2, the distal end of the projection 48b is located radially outward of the outer peripheral surface 47a of the insulating base. Specifically, the distal end of the projection 48b slightly protrudes from the outer peripheral surface 47a of the insulating base.
In embodiment 1, when the abrasion powder is entirely accumulated in the concave groove, the commutator segments are short-circuited by the abrasion powder. On the other hand, in embodiment 2, the distal end of the protrusion is located radially outward of the outer peripheral surface of the insulating base. Therefore, the abrasion powder is divided in the circumferential direction by the protrusion, and the time for short-circuiting between the commutator segments by the abrasion powder can be slightly extended, thereby further extending the life.
(embodiment 3)
A commutator for a brush motor according to embodiment 3 of the present invention will be described with reference to fig. 5. In fig. 5, the same components as those in fig. 1 to 4 are denoted by the same reference numerals, and redundant portions will not be described.
In embodiment 2, the distal end of the projection 48b is located radially outward of the outer peripheral surface 47a of the insulating base. On the other hand, in embodiment 3, the tip of the protrusion 48c is formed at a position not in contact with the brush 33, and the brush 33 simultaneously comes into sliding contact with the adjacent commutator segments. That is, the distal end of the projection 48c of embodiment 3 projects radially outward beyond the distal end of the projection 48b of embodiment 2, and when the contact portion 33a of the brush is located radially inward most, the distal end of the projection 48c is formed at a height position at which the contact portion 33a of the brush does not come into contact.
In embodiment 2, when the tip of the protrusion 48c extends outward in the radial direction, the time for short circuit between commutator segments due to abrasion powder can be increased. However, when the tip of the projection is formed at a height position where the tip contacts the contact portion of the brush, the projection comes into sliding contact with the contact portion of the brush when the commutator rotates. In this way, regardless of whether the protrusion contributes to the rotational force of the rotor, mechanical abrasion powder due to the protrusion increases, resulting in a shortened life.
On the other hand, in this example, the distal end of the projection 48c is formed at a position not in contact with the contact portion 33a of the brush, and the brush is simultaneously in sliding contact with the adjacent commutator segments. Therefore, the occurrence of mechanical abrasion powder that does not contribute to the rotational force of the rotor by the projection 48c can be suppressed, and the reduction of the life can be prevented.
(embodiment 4)
A commutator for a brush motor according to embodiment 4 of the present invention will be described with reference to fig. 6. In fig. 6, the same components as those in fig. 1 to 5 are denoted by the same reference numerals, and redundant portions will not be described.
In the above embodiment, the protrusion is erected along the gap from the inside of the groove of the insulating base to the radially outside. On the other hand, in embodiment 4, the protrusion 48d is erected along the gap from the outer peripheral surface of the insulating base 61 to the radially outer side, and the insulating base 61 has a circular cross-sectional shape in which no groove is formed on the outer peripheral surface.
Specifically, in the insulating base 61 having a circular cross-sectional shape on the outer peripheral surface, the projection 48d extending radially outward from the outer peripheral surface is erected on the insulating base 61. The projection 48d is continuously formed in the same shape along the gap in a state of not contacting the commutator segment.
The tip of the projection 48d is located radially inward of the outer peripheral surface 49b of the arcuate portion. More preferably, the tip of the protrusion 48d is formed at a position not in contact with the contact portion 33a of the brush, and the brush is simultaneously in sliding contact with the adjacent commutator segments. That is, when the contact portion 33a of the brush falls into the gap 49e and is located at the radially innermost position, the tip of the projection 48d is formed at a height position not in contact with the contact portion 33a of the brush.
In this example, the insulating base has no recessed groove and abrasion powder is less likely to accumulate in the gap between the commutator segments, as compared with the examples of embodiments 1 to 3. However, in this example, the time required for short-circuiting between segments due to abrasion powder can be slightly extended and the service life can be extended, as compared with a commutator in which the outer peripheral surface has a circular cross-sectional shape and segments are circumferentially arranged on an insulating base having no projection formed on the outer peripheral surface.
(embodiment 5)
A brush motor 100 according to embodiment 5 of the present invention will be described with reference to fig. 7 to 9. In fig. 7 to 9, the same components as those in fig. 1 to 6 are denoted by the same reference numerals, and redundant portions will not be described.
The commutator of the above embodiment is a cylindrical commutator in which commutator segments are arranged cylindrically around a rotation shaft. On the other hand, the commutator 146 of embodiment 5 is a flat plate type in which commutator segments 149 are arranged around a rotation shaft in a flat plate shape.
The brush 33 of the above embodiment has a flat contact portion 33a at the distal end thereof, which contacts the commutator 46. On the other hand, in embodiment 5, the brush 133 has a curved contact portion 133a protruding outward and having a distal end contacting the commutator 146.
The commutator 146 has an insulating base 147 and three commutator segments 149.
The insulating base 147 is formed in a flat plate shape using a thermoplastic resin.
The commutator segment 149 has a contact portion 149a which is in sliding contact with the brush, and a terminal portion, not shown, which is electrically connected to the tip of the copper wire 43.
The contact portion 149a is formed of a triangular conductor in which a copper plate is plated with gold. The contact portions 149a are arranged on one outer surface 147a of the insulating base 147 with a gap 149e therebetween in the circumferential direction around the rotation axis.
The gaps 149e between adjacent segments are continuously formed from the radially inner side to the radially outer side of the segments 149 in the direction perpendicular to the axial direction, around the rotary shaft 41, and with the same width.
A groove 147b is formed in the insulating base 147 at a position corresponding to the gap 149e between adjacent commutators. The groove 147b is continuously formed along the gap 149e from the radially inner side to the outer side of the commutator segment 149 with the same width.
In fig. 7, the concave groove 147b is formed to open in the radial direction side. The concave groove 147b has a bottom surface 147b1 having a width larger than that of the gap 149e, and a side surface 147b2 having a predetermined depth. In fig. 9, the concave groove 147b is formed in line symmetry with respect to a line 151 parallel to the axis of the rotary shaft 41, passing through the center of the gap 149e in the circumferential direction.
In fig. 9, an integral protrusion 148a (or a protrusion portion) is provided so as to stand upward in the axial direction from the inside of the concave groove 147 b. The projection 148a is disposed at a position corresponding to (or facing) the gap 149 e. That is, the projection 148a is formed continuously from the radially inner side to the radially outer side of the commutator segment in the same shape along the gap 149 e.
In fig. 9, the projection 148a is erected at the center in the circumferential direction of the gap 149 e. Specifically, the projection 148a is formed so as to pass through the center of the gap 149e in the circumferential direction and be line-symmetrical with respect to a line 151 parallel to the axis of the rotary shaft 41.
The projection 148a is formed so as not to contact the adjacent commutator segment 149, and at least the tip of the projection 148a is completely visible from the gap 149 e.
The tip of the projection 148a is formed inward of the outer surface of the contact portion 149a so as not to project outward of the outer surface of the contact portion 149 a.
In addition, when the motor is assembled, the distal end of the projection 148a is formed inside the outer surface 147a of the insulating base so that the projection 148a of the single insulating base is not deformed by an external force.
Thus, the commutator 146 of the present example has: a flat plate-like insulating base 47; and three commutator segments 149 arranged on the outer surface 147a of the insulating base with a gap 149e therebetween in the circumferential direction.
The commutator segment 149 has a contact portion 149a which is in sliding contact with the brush 133 and a terminal portion.
The insulating base 147 has a groove 147b at a position corresponding to the gap 149 e.
A projection 148a is formed in the concave groove 147b to stand from the inside to the outside.
The projection 148a is continuously formed along the gap 149e without contacting the commutator segment 149.
The distal end of the projection 148a is located inward of the outer surface of the contact portion 149 a.
In this way, the projection is continuously formed along the gap without contacting the commutator segment. Therefore, the wear powder entering the groove is divided in the circumferential direction by the protrusion, and the wear powder is less likely to accumulate unevenly in one of the grooves. As a result, short-circuiting between segments of the commutator due to abrasion powder can be prevented in a state where there is a sufficient space in the recess on the rotation direction side of the commutator.
Therefore, the space in the recessed groove can be effectively used as compared with the conventional example, the time for short-circuiting between commutator segments due to abrasion powder can be extended, and the service life can be extended.
When the distal end of the projection 148a projects from the outer surface 147a of the insulating base, the projection of the single insulating base may be deformed by an external force during the assembly of the motor.
On the other hand, when the distal end of the projection 148a is formed inward of the outer surface 147a of the insulating base, the projection of the insulating base of a single product is not deformed by an external force at the time of assembling the motor, and the quality at the time of assembling the motor is improved.
The projection 148a is erected at the center of the gap 149e in the circumferential direction. Therefore, the wear powder entering the groove 147b is easily equally divided in the circumferential direction by the projection, and is less likely to be biased to one side of the rotation direction of the groove, and the space inside the groove is easily and effectively used.
(embodiment 6)
A commutator for a brush motor according to embodiment 6 of the present invention will be described with reference to fig. 10. In fig. 10, the same components as those in fig. 1 to 9 are denoted by the same reference numerals, and redundant portions will not be described.
In embodiment 5, the distal end of the projection 148a is located inward of the outer surface 147a of one surface of the insulating base. On the other hand, in embodiment 6, the distal end of the projection 148b is located outside the outer surface 147a of the one surface of the insulating base. Specifically, the tip of the projection 148b slightly protrudes from the outer surface 147a of the insulating base.
That is, in embodiment 5, when the abrasion powder is entirely accumulated in the concave groove, the commutator segments are short-circuited by the abrasion powder. On the other hand, in embodiment 6, the distal end of the projection 148b is located outside the outer surface of the insulating base. Therefore, the abrasion powder is divided in the circumferential direction by the projection, and the time until short circuit between the commutator segments due to the abrasion powder can be slightly extended, thereby further extending the lifetime.
(embodiment 7)
A commutator for a brush motor according to embodiment 7 of the present invention will be described with reference to fig. 11. In fig. 11, the same components as those in fig. 1 to 10 are denoted by the same reference numerals, and redundant portions will not be described.
In embodiment 6, the distal end of the projection 148b is located outside the outer surface 147a of one surface of the insulating base. On the other hand, in embodiment 7, the tip of the projection 148c is formed at a position not in contact with the brush 133, and the brush 133 simultaneously makes sliding contact with each adjacent segment. That is, the tip of the projection 148c of embodiment 7 projects further than the tip of the projection 148b of embodiment 6. Specifically, in a case where the contact portion 133a of the brush falls into the gap 149e, the tip of the projection 148c is formed at a height position not in contact with the contact portion 133a of the brush.
In embodiment 6, the time required for short-circuiting between commutator segments due to abrasion powder can be increased as the distal ends of the projections 148c extend outward. However, when the tip of the projection is formed at a height position where the tip contacts the contact portion of the brush, the projection comes into sliding contact with the contact portion of the brush when the commutator rotates. Therefore, regardless of the fact that the protrusions do not contribute to the rotational force of the rotor, the mechanical abrasion powder due to the protrusions increases, resulting in a shortened life.
On the other hand, in this example, the distal end of the projection 148c is formed at a position not in contact with the contact portion 133a of the brush, the brush is simultaneously in sliding contact with the adjacent commutator segments, and the projection 148c is not in contact with the contact portion 133a of the brush. Therefore, the generation of mechanical abrasion powder that does not contribute to the rotational force of the rotor by the projection 148c can be suppressed, and the reduction of the life can be prevented.
(embodiment 8)
A commutator for a brush motor according to embodiment 8 of the present invention will be described with reference to fig. 12.
In fig. 12, the same components as those in fig. 1 to 11 are denoted by the same reference numerals, and redundant portions will not be described.
In embodiments 5 to 7, the protrusion is erected from the inside of the groove of the insulating base to the outside. On the other hand, in embodiment 8, the projection 148d is erected on a flat insulating base having no recessed groove formed on the outer surface.
Specifically, the present embodiment includes a flat plate-shaped insulating base 161 and a plurality of commutator segments 149, and the plurality of commutator segments 149 are arranged on one surface of the insulating base 161 with a gap therebetween in the circumferential direction.
The commutator segment 149 has a contact portion and a terminal portion which are in sliding contact with the brush.
A projection 148d is formed on one surface of the insulating base.
The projection 148d is formed along the gap 149e without contacting the commutator segment.
The tip of the projection 148d is located inward of the outer surface of the contact portion 149 a. More preferably, the tip of the protrusion 148d is formed at a position not in contact with the contact portion 133a of the brush, and the brush is simultaneously in sliding contact with the adjacent commutator segments. That is, in a case where the contact portion 133a of the brush falls into the gap 149e, the tip of the projection 148d is formed at a height position not in contact with the contact portion 133a of the brush.
In this example, the insulating base has no recessed groove and abrasion powder is less likely to accumulate in the gap between the commutator segments, as compared with the examples of 5 to 7. However, in this example, the time for short circuit between the commutator segments due to abrasion powder can be slightly extended and the service life can be extended, as compared with a commutator in which commutator segments are arranged in a flat plate shape in the circumferential direction on a flat plate-shaped insulating base having no projection formed on the outer surface.
The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention except for the above-described embodiments.
(modification 1)
In embodiments 1 to 4, the protrusion is provided upright at the center in the circumferential direction of the gap 49e, but the present invention is not limited to this.
For example, as shown in fig. 13, the projection 48e may be provided so as to stand upright while moving from the center of the gap 49e in the circumferential direction to any one of the circumferential directions. That is, the entire projection may be moved slightly in the circumferential direction. However, the projection 48e is formed so as not to contact the adjacent arc portion 49a, and the tip end of the projection 48e can be completely seen from the gap 49e when viewed from the radially outer side.
(modification 2)
In embodiments 1 to 4, the protrusion is formed on the insulating base along the gap 49e from the upper end to the lower end of the arc portion 49a, but the present invention is not limited thereto.
For example, as shown in fig. 14, the protrusion 48f may be provided to partially stand discontinuously along the gap 49e in correspondence with the brush 33 having a fork shape with a split distal end. That is, the protrusion 48f is formed on the insulating base in the axial direction only at the portion where the brush 33 is in sliding contact with the arc portion 49 a.
(modification 3)
In embodiments 1 to 3, the recessed groove has an inner bottom surface having a width larger than the gap width and an inner peripheral surface having a predetermined depth, but the present invention is not limited thereto.
For example, as shown in fig. 15, the concave groove 47c may have an inner bottom surface having the same width as the gap 49e and an inner peripheral surface having a predetermined depth (modification 3A).
For example, as shown in fig. 16, the concave groove 47d may have an inner bottom surface having a width smaller than that of the gap 49e and an inner peripheral surface having a predetermined depth (modification 3B).
(modification 4)
In addition, in embodiments 1 to 4, the gaps between adjacent commutators are formed parallel to the axial direction, but the present invention is not limited thereto.
For example, as shown in fig. 17, the gaps between adjacent commutators may be formed slightly inclined with respect to the axial direction to reduce the generation of abrasion powder. That is, the slightly inclined gap 49f can be applied to embodiment 1 to embodiment 3 or modifications 1 to 3 thereof, and the commutator segment 52 or the groove or the protrusion 48i corresponding to the slightly inclined gap 49f is formed (modification 4A).
The slightly inclined gap can be applied to embodiment 4 or modifications 1 and 2 (modification 4B) thereof.
(modification 5)
In the embodiments 5 to 8, the protrusion is erected at the center in the circumferential direction of the gap 149e, but the present invention is not limited thereto.
For example, as shown in fig. 18, the projection 148e may be provided so as to stand upright while moving from the center of the gap 149e in the circumferential direction to any one of the circumferential directions. That is, the entire projection may be moved a little in the circumferential direction. However, the projection 148e is formed so as not to contact the adjacent commutator segment 149, and the tip of the projection 148e can be completely seen from the gap 149 e.
(modification 6)
In the embodiments 5 to 8, the projection is continuously formed from the radially inner side to the radially outer side of the commutator segment along the gap 149e, but the present invention is not limited thereto.
For example, as shown in fig. 19, the projection 148f may be provided to partially stand discontinuously along the gap 149e in correspondence with the brush 133 having a fork shape with a split distal end. That is, the protrusion 148f is formed on the insulating base only at the portion where the brush 133 is in sliding contact with the commutator segment 149.
(modification 7)
In embodiments 5 to 7, the recessed groove has an inner bottom surface having a width larger than the gap width and an inner peripheral surface having a predetermined depth, but the present invention is not limited thereto.
For example, as shown in fig. 20, the concave groove 147c may have an inner bottom surface having the same width as the gap 149e and an inner peripheral surface having a predetermined depth (modification 7A).
For example, as shown in fig. 21, concave groove 147d may have an inner bottom surface having a width smaller than that of gap 149e and an inner peripheral surface having a predetermined depth (modification 7B).
(modification 8)
In addition, in the 5 th to 8 th embodiments, the gap 149e between the adjacent commutator segments is formed in the direction perpendicular to the axial direction, but the present invention is not limited thereto.
For example, as shown in fig. 22, the gaps 149f between adjacent commutators may be formed slightly inclined with respect to the direction perpendicular to the axial direction, in order to reduce the generation of abrasion powder. That is, the slightly inclined gap 149f can be applied to embodiment 5 to embodiment 7 or modifications 5 to 7 thereof, and the commutator segment 152 or the groove or the protrusion 148i corresponding to the slightly inclined gap 149f is formed (modification 8A).
The slightly inclined gap can be applied to embodiment 8 or modifications 5 and 6 (modification 8B) thereof.
Further, if the brush motor includes the commutator, a brush motor having an extended life can be obtained.
The above-described protrusion is provided to stand integrally with the insulating base, but the above-described protrusion may be provided to stand separately from the insulating base.
The number of commutator segments is three, but a plurality of commutator segments may be provided.
Claims (10)
1. A commutator, comprising: an insulating base having a circular cross-sectional shape on the outer peripheral surface; and a plurality of commutator segments arranged on the outer peripheral surface of the insulating base with a gap therebetween in the circumferential direction, the commutator is characterized in that the commutator segment has an arc portion and a terminal portion, the arc portion has an outer peripheral surface in sliding contact with the brush and an inner peripheral surface in contact with an outer peripheral surface of the insulating base, the insulating base has a groove at a position corresponding to the gap, a protrusion extending from the inside to the outside in the radial direction and formed along the gap so as not to contact the commutator segment is erected on the groove, and the protrusion has a triangular or trapezoidal cross-sectional shape, so as to separate abrasion powder generated from the commutator segment and accumulated in the groove in the circumferential direction in the groove, the tip of the projection is located radially inward of the outer peripheral surface of the arc portion, and the inner peripheral surface is circumferentially longer than the outer peripheral surface of the insulating base with which the inner peripheral surface is in contact.
2. The commutator of claim 1 wherein the distal end of the projection is formed radially inward of the outer peripheral surface of the insulating base.
3. The commutator of claim 1 wherein the distal end of the projection is formed radially outward of the outer peripheral surface of the insulating base.
4. A commutator, comprising: a flat insulating base; and a plurality of commutator segments arranged on one surface of the insulating base with a gap therebetween in a circumferential direction, the commutator is characterized in that the commutator segment is provided with a contact part and a terminal part, one surface of which is in sliding contact with the brush, the other surface of the contact portion is in contact with the one surface of the insulating base having a groove at a position corresponding to the gap, a protrusion portion that is formed along the gap so as not to contact the commutator segment and that is erected from the inside toward the outside, the protrusion portion having a triangular or trapezoidal cross-sectional shape, so as to separate abrasion powder generated from the commutator segment and accumulated in the groove in the circumferential direction in the groove, the distal end of the protrusion is located inward of the outer surface of the contact portion, and the contact portion is longer in the circumferential direction than the one surface of the insulating base with which the other surface of the contact portion is in contact.
5. The commutator of claim 4, wherein the tip of the projection is formed inward of the outer surface of the one surface.
6. The commutator of claim 4, wherein the tip of the projection is formed to be more outside than the outer surface of the one surface.
7. The commutator according to any one of claims 1 to 6, wherein the tip of the projection is located at a position not in contact with the brush which is in sliding contact with the adjacent segments at the same time.
8. A commutator according to any one of claims 1 to 6, wherein the projections are formed continuously along the gap.
9. The commutator according to any one of claims 1 to 6, wherein the projection is erected at a center in a circumferential direction of the gap.
10. A brush motor having the commutator claimed in any one of claims 1 to 9.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2018017039A JP7090874B2 (en) | 2018-02-02 | 2018-02-02 | Commutator and brushed motor with this commutator |
| JP2018-017039 | 2018-02-02 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110137762A CN110137762A (en) | 2019-08-16 |
| CN110137762B true CN110137762B (en) | 2021-05-11 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811207140.0A Active CN110137762B (en) | 2018-02-02 | 2018-10-17 | Commutator and brush motor with same |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP7090874B2 (en) |
| CN (1) | CN110137762B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000102225A (en) * | 1998-09-28 | 2000-04-07 | Toshiba Tec Corp | Dynamo-electric machine commutator and motor-driven blower provided with the same |
| CN104979731A (en) * | 2014-04-02 | 2015-10-14 | 德昌电机(深圳)有限公司 | Motor commutator, carbon-containing product and manufacturing method therefor |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5291103A (en) * | 1976-01-27 | 1977-08-01 | Matsushita Electric Works Ltd | Commutator |
| JPS58212347A (en) * | 1982-05-31 | 1983-12-10 | Matsushita Electric Works Ltd | Cylindrical commutator |
| JP3911879B2 (en) | 1998-11-02 | 2007-05-09 | 株式会社デンソー | AC generator for vehicles |
| JP2002210410A (en) | 2001-01-18 | 2002-07-30 | Tokyo Parts Ind Co Ltd | Axially gapped eccentric rotor provided with halt position holding means and flat coreless vibration motor using the eccentric rotor |
| DE102013109960A1 (en) | 2012-09-12 | 2014-03-13 | Johnson Electric S.A. | Brushed motor commutator with spark suppression and manufacturing process |
| DE102014113760A1 (en) * | 2014-04-07 | 2015-10-08 | Asmo Co., Ltd. | Motor with brush |
-
2018
- 2018-02-02 JP JP2018017039A patent/JP7090874B2/en active Active
- 2018-10-17 CN CN201811207140.0A patent/CN110137762B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000102225A (en) * | 1998-09-28 | 2000-04-07 | Toshiba Tec Corp | Dynamo-electric machine commutator and motor-driven blower provided with the same |
| CN104979731A (en) * | 2014-04-02 | 2015-10-14 | 德昌电机(深圳)有限公司 | Motor commutator, carbon-containing product and manufacturing method therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP7090874B2 (en) | 2022-06-27 |
| JP2019134643A (en) | 2019-08-08 |
| CN110137762A (en) | 2019-08-16 |
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