JP2015116063A - DC motor with brush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DC motor with a brush that not only secures insulation performance but also achieves lower cost.SOLUTION: A DC motor 1 with a brush includes a first insulator 33 and a second insulator 34 that cover a core 31 from both sides in a direction of a rotation shaft 15 and insulate a coil 31 from a coil 32 and the rotation shaft 15 from the coil 32. A fourth insulation part 34b is formed in the second insulator in a direction separated from the core 31. The first insulator 33 and second insulator 34 are made to be the same shape. Between an end part 32b on the commutator 40 side in the direction of the rotation shaft 15, of the coil 32, and a commutator piece 42, the fourth insulation part 34b and a projection 41a formed on a commutator insulation part 41 are overlapped via a gap g.

Description

  The present invention relates to a brushed DC motor, and more particularly to an insulating structure between a coil and a rotating shaft.

  For example, as a conventional configuration, Patent Document 1 discloses an electric machine in which a plurality of side plates serving as insulators formed of an insulating material are disposed on both sides in the rotation axis direction of a rotor core and wound around the rotation axis core. A DC motor with a brush that insulates a child winding from a rotating shaft is disclosed.

JP 2004-104874 A

  However, in the motor shown in Patent Document 1, the shape of the insulator is different. If the parts constituting the motor are different, the number of parts of the motor increases, which affects the cost of the motor.

  Accordingly, the present invention has been made to solve the above-described problems, and provides a brushed DC motor that achieves lower cost than the conventional configuration while ensuring the insulation performance between the winding and the rotating shaft. With the goal.

  In order to solve the above problems, a brushed DC motor according to a first aspect is provided with a housing, a rotating shaft rotatable with respect to the housing via a first bearing and a second bearing, and a rotating shaft. A core that rotates integrally with the shaft, a coil wound around the core, a commutator insulating portion provided on one side of the rotating shaft direction with respect to the core, and a plurality of commutator pieces provided on the outer periphery of the commutator insulating portion A commutator, a brush for supplying power to the commutator piece, and a first covering the core and the coil and insulating the rotary shaft and the coil by covering the core from both sides in the direction of the rotational axis. A direct current motor with a brush including an insulator and a second insulator, wherein boss portions are formed in the first insulator and the second insulator, respectively, in a direction away from the core, and the first insulator and the second insulator The insulator is the same shape, and in the direction of the rotation axis, the boss part and the protrusion part formed on the commutator insulating part are interposed between the end part on the commutator side of the coil and the commutator piece via a gap. They are overlapping.

  According to this, since the 1st insulator and the 2nd insulator are the same shapes, the number of parts of a motor can be decreased more. Therefore, the cost of the motor can be reduced. In addition, in the direction of the rotation axis, the boss and the protrusion formed on the commutator insulator overlap with each other through the gap between the end of the commutator side of the coil and the commutator piece. A portion of the shaft between the core and the commutator is covered with a boss portion and a projection portion. Therefore, the rotating shaft and the coil can be reliably insulated.

  According to a second aspect of the present invention, in the motor with brush according to the first aspect, the outer peripheral dimension of the protrusion is smaller than the outer peripheral dimension of the commutator insulating part.

  According to this, since the outer peripheral dimension of the protrusion is formed smaller than the outer peripheral dimension of the commutator insulating part, the space between the commutator and the core can be made wider. Therefore, a space for handling the coil can be further secured.

  According to a third aspect of the present invention, in the brushed DC motor according to the first or second aspect, the length of the boss portion in the rotation axis direction is a coil end protrusion in which the coil protrudes from the core in the rotation axis direction. It is longer than the amount.

  According to this, the length of the boss portion in the direction of the rotation axis is equal to or longer than the coil end protruding amount by which the coil protrudes from the core in the direction of the rotation axis, so that the rotation shaft and the coil are insulated. It is set to a sufficient length. Therefore, since the length of the first insulator and the second insulator in the rotation axis direction can be shortened to a necessary and sufficient length, the length of the motor in the rotation axis direction can be further shortened.

It is an axial sectional view showing the composition of one embodiment of the direct-current motor with brush by the present invention. It is a perspective view of the rotating shaft, core, 1st insulator, and 2nd insulator which are shown in FIG. It is sectional drawing along the III-III line | wire of the DC motor with a brush shown in FIG. It is the elements on larger scale of the invention important point of the DC motor with a brush shown in FIG. 1, and is an enlarged view of the site | part by which the 2nd insulator was arrange | positioned. It is the elements on larger scale of the invention essential point of the DC motor with a brush shown in FIG. 1, and is an enlarged view of the site | part by which the 1st insulator was arrange | positioned.

  An embodiment of a brushed DC motor 1 according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the brushed DC motor 1 in this embodiment includes a housing 10, a stator 20, a rotor 30, a commutator 40, and a brush 50.

  The housing 10 has a cylindrical shape and is formed of a metallic yoke 11 having a bottomed shape with one end opened, and is fixed to an opening portion of the yoke 11, and is formed of an insulating material such as a resin. A holder 12, a first bearing 13 fixed to the yoke 11, a second bearing 14 fixed to the holder 12, and a metallic rotating shaft 15 rotatably supported by the bearings 13 and 14 are provided. That is, the rotary shaft 15 is a shaft that can rotate with respect to the housing 10 via the first bearing 13 and the second bearing 14. Each of the bearings 13 and 14 is, for example, a ball bearing.

  The stator 20 is a fixed field, and is fixed to the inner peripheral surface of the yoke 11 by, for example, adhesion or press fitting. In the present embodiment, the stator 20 is a permanent magnet formed of a ferrite magnet.

  The rotor 30 is a rotating armature, and includes a core 31 and a plurality of coils 32 that are fixed to the rotary shaft 15 between the first bearing 13 and the second bearing 14 and inside the stator 20. The core 31 is provided on the rotating shaft 15 and rotates integrally with the rotating shaft 15. Specifically, the core 31 has a plurality of slots 31a that are fixed to the rotary shaft 15 by, for example, press-fitting, and are radially protruded outward as shown in FIGS. Yes. In this embodiment, the core 31 is formed in the shape which extended the shape shown in FIG. 3 to the rotating shaft 15 direction. The core 31 is a laminated steel plate formed by stacking a plurality of electromagnetic steel plates. The coil 32 is wound around the core 31. Specifically, the coil 32 is formed by winding a conducting wire W around the slot 31a. The coil 32 magnetizes the slot 31a when the conducting wire W is energized.

  The commutator 40 is a switch that periodically switches the direction of the current flowing through the conductor W between an external circuit (not shown) electrically connected to the motor 1 and the rotor 30. The commutator 40 includes a commutator insulator 41 and a plurality of commutator pieces 42.

  The commutator insulator 41 is provided on one side in the direction of the rotary shaft 15 with respect to the core 31, and insulates the rotary shaft 15 and the commutator piece 42. In the present embodiment, as shown in FIG. 1, the commutator insulator 41 is formed in a cylindrical shape, and is fixed to the rotating shaft 15 on the right side in FIG. The commutator insulating portion 41 is formed by injection molding an insulating material such as phenol resin, for example.

  And the commutator insulation part 41 has the protrusion part 41a. The protrusion 41a protrudes toward the core 31 and is formed in a cylindrical shape in the present embodiment. And as shown in FIG. 4, the outer periphery dimension D1 of the projection part 41a is formed smaller than the outer periphery dimension D2 of the commutator insulation part 41. As shown in FIG.

  The commutator piece 42 is an electrode for allowing a current to flow through the conducting wire W, is provided on the outer periphery of the commutator insulating portion 41, and is connected to the conducting wire W. The commutator piece 42 is fixed to the commutator insulator 41 by, for example, insert molding. Further, the commutator piece 42 is connected to the lead wire W by bending the end portion on the core 31 side outward in the radial direction, and welding after sandwiching the lead wire W. In the present embodiment, the conducting wire W is wound around a slot 31a disposed at a position spaced apart from the commutator piece 42 to which the conducting wire W is connected in the circumferential direction. For example, the conducting wire W is wound around a slot 31a disposed at a position displaced by approximately 90 degrees in the circumferential direction from the commutator piece 42 to which the conducting wire W is connected.

  The rotor 30 further includes a first insulator 33 and a second insulator 34. The 1st insulator 33 and the 2nd insulator 34 are each covered with respect to the core 31 from the both sides of the rotating shaft 15 direction, and insulate with the core 31 and the coil 32, and insulate with the rotating shaft 15 and the coil 32. . In the present embodiment, the first insulator 33 is fixed to the core 31 on the first bearing 13 side in the direction of the rotation shaft 15. That is, the first insulator 33 insulates the coil 32 from the part between the core 31 and the first bearing 13 in the rotating shaft 15 and the part on the first bearing 13 side in the core 31. The conducting wire W is wound around each slot 31 a via the first insulator 33 and the second insulator 34.

  The 1st insulator 33 has the 1st insulation part 33a and the 2nd insulation part 33b (equivalent to the boss | hub part of a claim). The first insulating portion 33 a is a portion that insulates the coil 32 from the portion on the first bearing 13 side in the core 31. As shown in FIGS. 2 and 3, the first insulating portion 33 a has an end surface shape portion 33 aa along the shape of the end surface on the first bearing 13 side in the core 31 and an outer shape between adjacent slots 31 a. A plurality of V-shaped portions 33ab formed in a substantially V shape are integrally formed. Thereby, the 1st insulation part 33a can prevent the site | part by the side of the 1st bearing 13 in the core 31, and the coil 32 from contacting.

  The second insulating portion 33 b is a portion that is formed in a direction away from the core 31 and insulates the coil 32 from the portion between the core 31 and the first bearing 13 in the rotating shaft 15. That is, the second insulating portion 33 b is a portion that insulates the rotating shaft 15 and the coil 32 in the first insulator 33. The second insulating portion 33 b is formed in a cylindrical shape along the outer periphery of the rotating shaft 15.

  Further, as shown in FIG. 5, the length L1 of the second insulating portion 33b in the direction of the rotation axis 15 is longer than the coil end protrusion amount L2 from which the coil 32 protrudes from the core 31 in the direction of the rotation axis 15. Yes. In the present embodiment, the coil end protrusion amount L2 is the length in the direction of the rotary shaft 15 from the end surface of the core 31 on the first bearing 13 side to the end portion 32a of the coil 32 on the first bearing 13 side. The length L1 is determined so that the rotating shaft 15 and the coil 32 do not come into contact with each other even if the coil end protrusion amount L2 varies. Variations in the coil end protrusion L2 are caused by variations in the diameter of the conductive wire W, variations in the shape of the coil 32 caused by the overlapping of the conductive wires W wound around the slots 31a, and the like. Thereby, the 2nd insulation part 33b can prevent the site | part between the core 31 and the 1st bearing 13 in the rotating shaft 15, and the coil 32 from contacting.

  In the present embodiment, the second insulator 34 is fixed to the core 31 on the second bearing 14 side in the direction of the rotary shaft 15. In other words, the second insulator 34 insulates the portion between the core 31 and the commutator 40 in the rotating shaft 15 and the portion on the commutator 40 side in the core 31 from the coil 32 and the conductive wire W.

  As shown in FIG. 1, the second insulator 34 has a third insulating portion 34 a and a fourth insulating portion 34 b (corresponding to a boss portion in the claims). The third insulating portion 34 a is a portion that insulates the portion on the commutator 40 side of the core 31 from the coil 32 and the conductive wire W. The fourth insulating portion 34 b is formed in a direction away from the core 31, and is a portion that insulates the portion between the core 31 and the commutator 40, the coil 32, and the conductive wire W in the rotating shaft 15. Here, the first insulator 33 and the second insulator 34 have the same shape. The third insulating portion 34a has the same shape as the first insulating portion 33a. The fourth insulating portion 34b has the same shape as the second insulating portion 33b. That is, as shown in FIG. 4, the length of the fourth insulating portion 34b in the direction of the rotational axis 15 is the same as the length L1 of the second insulating portion 33b in the direction of the rotational shaft 15.

  Here, as shown in FIG. 4, the fourth insulating portion 34 b and the commutator insulating portion 41 are formed between the end portion 32 b on the side of the commutator 40 and the commutator piece 42 in the direction of the rotating shaft 15. The projected portion 41a overlaps with the gap g. That is, the fourth insulating portion 34b is disposed inside the protruding portion 41a, and the inner peripheral dimension d1 of the protruding portion 41a is determined to be larger than the outer peripheral dimension D3 of the fourth insulating portion 34b. Thereby, a gap g is formed between the inner peripheral surface of the protrusion 41a and the outer peripheral surface of the fourth insulating portion 34b. In the present embodiment, the dimensions d1 and D3 are determined so that the gap g is smaller than the linear shape of the conducting wire W. Here, since the shape of the second insulating portion 33b and the shape of the fourth insulating portion 34b are the same, the outer peripheral dimension of the second insulating portion 33b is the same as the dimension D3 in the fourth insulating portion 34b.

  As shown in FIG. 1, the lengths of the first insulating portion 33 a and the third insulating portion 34 a in the direction of the rotation axis 15 are the first length when the first insulator 33 and the second insulator 34 are assembled to the core 31. A dimension L3 between the insulator 33 and the second insulator 34 is formed to be a predetermined dimension or less. The predetermined dimension is set to a length that can prevent contact between the coil 32 and a portion of the core 31 that is not covered by the insulators 33 and 34 when the conductive wire W is wound around the slot 31a. Accordingly, the first insulator 33 and the second insulator 34 can prevent the coil 32 from contacting the portion of the core 31 that is not covered with the insulators 33 and 34.

  Also, as shown in FIG. 4, the length L4 of the protrusion 41a in the direction of the rotation axis 15 is set to a length that overlaps the fourth insulating portion 34b. In the present embodiment, the length L4 is a position where the commutator insulator 41 of the core 31 or the commutator 40 is press-fitted into the rotary shaft 15 and the dimensions of each member vary. The protruding portion 41a and the fourth insulating portion 34b are determined to overlap each other. Thereby, in the part between the core 31 and the commutator 40 in the rotating shaft 15, since the 4th insulation part 34b and the projection part 41a always have covered the rotating shaft 15, the coil 32, the conducting wire W, the rotating shaft 15, Can prevent contact.

  The brush 50 supplies power to the commutator piece 42. The brush 50 is supported by the holder 12 and is in contact with the commutator piece 42 by being biased by a spring (not shown). The current from the external circuit is supplied to the commutator piece 42 via the brush 50.

  Then, by being supplied to the commutator piece 42 via the brush 50, a current flows through the coil 32, and a repulsive force between the magnetic force generated in the core 31 and the magnetic force of the stator 20 acts in the circumferential direction of the rotating shaft 15. Then, the rotor 30 is driven to rotate.

  According to this embodiment, since the first insulator 33 and the second insulator 34 have the same shape in the motor 1, the number of parts of the motor 1 can be further reduced. Accordingly, the cost of the motor 1 can be further reduced. Moreover, when the 1st insulator 33 and the 2nd insulator 34 are different shapes, the possibility of attaching the 1st insulator 33 and the 2nd insulator 34 accidentally can be excluded.

  Further, a protrusion formed on the fourth insulator 34 b and the commutator insulator 41 in the second insulator 34 between the end 32 b on the commutator 40 side of the coil 32 and the commutator piece 42 in the direction of the rotating shaft 15. Since the portion 41a overlaps with the gap g, the portion of the rotating shaft 15 between the core 31 and the commutator 40 is covered with the fourth insulating portion 34b and the protruding portion 41a. Therefore, the rotating shaft 15, the coil 32, and the conducting wire W can be reliably insulated.

  And since the outer periphery dimension D1 of the projection part 41a is formed smaller than the outer periphery dimension D2 of the commutator insulation part 41, the space between the commutator 40 and the core 31 can be made wider. Therefore, the tool used when routing the conducting wire W in a production facility or the like, and the space for handling the coil 32 and the conducting wire W can be further secured.

  Further, the length L1 in the direction of the rotation axis 15 of the second insulating portion 33b of the first insulator 33 is equal to or longer than the coil end protrusion amount L2 from which the coil 32 protrudes from the core 31 in the direction of the rotation axis 15. The length is determined to be sufficient to insulate the rotating shaft 15 and the coil 32 from each other. Therefore, since the length L1 of the first insulator 33 and the second insulator 34 in the direction of the rotating shaft 15 can be shortened to a necessary and sufficient length, the length of the motor 1 in the direction of the rotating shaft 15 is further shortened. be able to.

  The fitting portion between the second insulator 34 and the commutator 40 has a gap g. According to this, when the commutator 40 is assembled by press-fitting after the second insulator 34 is assembled to the rotating shaft 15, the second insulator 34 and the protrusion 41 a do not come into contact with each other. 40 can be positioned more accurately. In addition, since the second insulator 34 and the protrusion 41a are formed so that the gap g is smaller than the line W, the conductor W does not enter the gap g. Insulation can be performed more reliably.

In the present embodiment, the second insulator 34 and the protruding portion 41a are formed so that the second insulator 34 is located inside the protruding portion 41a in the fitting portion, but instead of this, the protruding portion 41a. May be formed so as to be inside the second insulator 34.
Moreover, although the projection part 41a is formed in the cylindrical shape, if it is a shape which fits a 2nd insulator, it will not be limited to a cylindrical shape.

  DESCRIPTION OF SYMBOLS 1 ... DC motor with brush, 10 ... Housing, 13 ... First bearing, 14 ... Second bearing, 15 ... Rotating shaft, 20 ... Stator, 30 ... Rotor, 31 ... Core, 31a ... Slot, 32 ... Coil, 32a, 32b ... end, 33 ... first insulator, 33a ... first insulating portion, 33b ... second insulating portion (boss portion), 34 ... second insulator, 34a ... third insulating portion, 34b ... fourth insulating portion (Boss part), 40 ... commutator, 41 ... commutator insulating part, 41a ... projection, 42 ... commutator piece, D1, D2, D3 ... outer periphery dimension, d1 ... inner periphery dimension, g ... gap, L1 ... long L2 ... coil end protrusion amount, W ... conductor.

Claims (3)

A housing;
A rotating shaft rotatable with respect to the housing via a first bearing and a second bearing;
A core provided on the rotating shaft and rotating integrally with the rotating shaft in the previous period;
A coil wound around the core;
A commutator having a commutator insulator provided on one side in the rotation axis direction with respect to the core, and a plurality of commutator pieces provided on the outer periphery of the commutator insulator,
A brush for supplying power to the commutator piece;
With a brush provided with a first insulator and a second insulator that are respectively covered from both sides in the direction of the rotation axis, and that insulate the core and the coil and insulate the rotation axis and the coil. A direct current motor,
Boss portions are formed on the first insulator and the second insulator, respectively, in a direction away from the core, and the first insulator and the second insulator have the same shape, and the coil rectification is performed in the rotation axis direction. Between the child side end and the commutator piece,
A DC motor with a brush, wherein the boss portion and a protrusion formed on the commutator insulating portion are overlapped with a gap.   The DC motor with brush according to claim 1, wherein an outer peripheral dimension of the protrusion is formed smaller than an outer peripheral dimension of the commutator insulating part. The DC length with a brush according to claim 1 or 2, wherein a length of the boss portion in the direction of the rotation axis is equal to or longer than a protruding amount of a coil end portion where the coil protrudes from the core in the rotation axis direction. motor.

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