JP2014075862A - Motor, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform aligned winding of a normal electric wire around taper-shaped teeth with stability.SOLUTION: A motor has a rotor arranged inside a stator. The stator comprises a plurality of teeth 42, and a plurality of coils formed by winding an electric wire around an individual tooth 42 in layers. Both lateral faces 42r and 42l of the teeth 42 facing a slot are inclined so as to be gradually close to each other toward a protruded end. An electric wire 50f is wound around the teeth 42 in an aligned state while being guided by guide parts. When seen from a direction of a rotation shaft, the electric wire 50f facing on one side is arranged in parallel to each other separately from each other by a gap s in a state extended orthogonally to the center line C of the teeth 42, and the electric wire 50f facing on the other side is arranged in non-parallel to each other separately from each other by the gap s in a state extended so as to be inclined to the center line C.

Description

  The present invention relates to an inner rotor type motor, and more particularly to a structure of a stator in which coils are aligned and wound for each tooth.

  In general, in a stator of this type of motor, a plurality of teeth are provided inside a cylindrical yoke. These teeth are covered with an insulating insulator and project radially from the inner peripheral surface of the yoke toward the center of rotation. The coil is formed by winding an electric wire around these teeth.

  There are distributed winding and concentrated winding methods for winding the electric wire. In the case of concentrated winding, a coil is formed for each tooth. Specifically, a coil is formed by winding an electric wire around each tooth while passing the electric wire through a slot (space) between the teeth.

  The so-called aligned winding, in which the electric wires are aligned and wound around the teeth, is used in many motors.

  For example, in the motor of Patent Document 1, the width of the teeth, that is, the dimension between both side surfaces facing the slot is formed in a uniform prismatic shape from the base side to the tip side, so that aligned winding can be performed stably. In addition, a group of guide grooves for guiding the winding direction of the electric wire is provided on both end faces of the teeth. Each one guide groove is arranged in parallel, and each other guide groove is arranged to be inclined by one pitch in order to shift the electric wires one by one.

  The shape of the teeth is generally a prismatic shape like the motor of Patent Document 1, but there is also a tapered shape in which the width of the teeth is gradually reduced from the root side to the tip side (Patent Document). 2, 3).

JP 2006-67778 A Japanese Patent Application Laid-Open No. 2004-64982 JP 2008-278628 A

  In order to improve motor performance, improvement of the coil space factor is an important issue, and aligned winding is one of the effective means for improving the coil space factor.

  In this regard, as shown in FIG. 1A, if the shape of the tooth 100 is a prismatic shape, when the first layer of the wire 101a is wound, the wire 101a is wound in the same state from the root to the tip of the tooth 100. Can do. Therefore, aligned winding can be stably performed relatively easily only by winding at a pitch of one electric wire.

  However, in this case, the cross section of the slot 102 has a trapezoidal shape in which the root portion of the tooth 100 is widened. Therefore, there is a problem that a gap is easily generated between adjacent coils 101. If the winding end portion of the coil 101 is gathered in the gap in order to reduce the gap, the electric wire 101a is easily broken and disturbed, and the winding process becomes complicated.

  On the other hand, as shown in FIG. 1 (b), if the shape of the teeth 100 is a tapered shape, the cross section of the slot 102 can be made rectangular. The gap between the coils 101 can be reduced.

  However, when the shape of the teeth is tapered, the winding state of the wire constantly changes when the first layer of the wire is wound, so that it is difficult to perform stable aligned winding because the coil is displaced.

  In order to realize stable aligned winding with tapered teeth, for example, in the motor of Patent Document 3, a hexagonal section winding is adopted and guided by a triangular guide. According to this method, aligned winding can be performed stably, but since the winding is special, there are disadvantages in terms of member cost and versatility.

  In the case of a general electric wire having a round cross section, as in Japanese Patent Application Laid-Open No. 2004-133620, by simply forming a guide according to the pitch of the electric wire, adjacent electric wires collide with each other, so that the electric wire cannot be guided properly.

  Accordingly, an object of the present invention is to provide a motor capable of stably winding an ordinary electric wire on a tapered tooth and improving the coil space factor.

  The motor according to the present invention is a motor in which a rotor that rotates about a rotation shaft is disposed inside a stator. The stator passes through a cylindrical yoke, a plurality of teeth projecting radially from the inner peripheral surface of the yoke toward the rotation axis, and a slot formed between the adjacent teeth. And a plurality of coils formed by winding an electric wire in layers.

  Both side surfaces of the teeth facing the slot are symmetrically inclined so as to gradually approach from the yoke side toward the protruding end. The electric wires of the first layer are wound around the teeth in order from the yoke side in an aligned state while being guided by a guide portion provided on the teeth.

  When viewed from the direction of the rotation axis, the first-layer electric wires facing one of them are arranged parallel to each other with a gap in a state extending perpendicular to the center line of the teeth, The first-layer electric wires facing each other are arranged so as to be inclined with respect to the center line and are arranged non-parallel to each other with a gap therebetween.

  That is, this motor is an inner rotor type motor, and the teeth of the stator are formed in a tapered shape. And the electric wire is wound around the teeth and the layered coil is formed. The first layer electric wires are guided and aligned by a guide portion provided on the teeth, and one end side thereof is arranged in parallel with a gap, and the other end side is for moving the electric wire. These are arranged non-parallel to each other with a gap while being inclined.

  Thus, by providing a gap between adjacent electric wires, it is possible to eliminate collisions between the electric wires. Accordingly, the electric wire can be properly guided by the guide, and the electric wire can be positioned stably.

  Furthermore, since the inclinations of the transition portions of the electric wires are not parallel to each other, stable aligned winding can be realized even with a tapered tooth while keeping the pitch of the electric wires constant.

  Specifically, when the outer diameter of the electric wire is A and the pitch of the first layer electric wire is P, it may be set so that P> A.

  For example, the inclination angle of each side surface of the tooth with respect to the center line is δ, and the distance between the centers of the two first-layer electric wires that are located closest to the yoke side and that are opposed to each other with the teeth interposed therebetween. When W, P ≧ A / Cos (θ + δ), where θ = ArcSin (A / W) can be set.

  Then, an appropriate pitch can be easily obtained based on geometric conditions.

  In this case, when the number of the slots is S, the diameter of the inner peripheral surface of the yoke is D, and the ratio of the width of the teeth to the width of the slot on the inner peripheral surface of the yoke is K, W An approximate value of π × D / (2 × S) × K + A can be used as the value.

  If it does so, since the setting of an optimal pitch can be obtained from each condition of a stator and the outer diameter of an electric wire, the design of a stator can be performed easily.

Specifically, based on the above-described relational expression, a first step for obtaining a correspondence relationship between the pitch P of the first-layer electric wires and the number S of the slots;
A motor may be manufactured using a method including the second step of setting the pitch P and the number S of slots based on the correspondence.

  In that case, it is preferable that in the second step, the number S of slots is set to the number of slots where the pitch P is a minimum value.

  According to the present invention, since an ordinary electric wire can be stably aligned and wound around a tapered tooth, the space factor of the coil can be improved.

(A), (b) is a figure for demonstrating the influence which the difference in the shape of teeth exerts on the space factor of a coil. It is a schematic sectional drawing which shows the internal structure of the motor of this embodiment. It is a schematic perspective view which shows the part of teeth. It is a schematic perspective view explaining the order which winds an electric wire around teeth. It is a schematic perspective view explaining the order which winds an electric wire around teeth. It is the schematic for demonstrating the conventional problem. It is the schematic which shows the arrangement | positioning state of the electric wire seen from the upper end surface side. It is the schematic which shows the arrangement | positioning state of the electric wire seen from the lower end surface side. It is the schematic which shows the arrangement | positioning state of the electric wire seen from the direction of the arrow X in FIG. It is the schematic which shows the electric wire located in the left side surface side. It is the schematic which shows arrangement | positioning of the electric wire from which a pitch becomes the minimum. It is the schematic for demonstrating the ratio K. FIG. It is a graph showing the correspondence between pitch P and the number of slots S.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the following description is merely illustrative in nature and does not limit the present invention, its application, or its use.

  FIG. 2 shows the motor 1 of the present embodiment. The motor 1 is an inner rotor type brushless motor, and a columnar rotor 2 is disposed inside a cylindrical stator 4 fixed to the inner surface of a motor case 3 with a slight gap therebetween. A shaft 5 is fixed to the center of the rotor 2 in a state where the center of the rotor 2 is aligned. The shaft 5 is rotatably supported by the motor case 3, and the rotor 2 and the shaft 5 rotate around the rotation axis J.

  The stator 4 includes a yoke 41, teeth 42, a coil 44, and the like.

  The yoke 41 has a cylindrical shape and is fixed to the inner surface of the motor case 3. A plurality of teeth 42 are provided with respect to the yoke 41, and project radially from the inner peripheral surface of the yoke 41 toward the rotation axis J at equal intervals. A pair of flange portions 43, 43 are provided on both sides of the protruding end of the tooth 42, and these flange portions 43 project in the opposite direction in the circumferential direction.

  The yoke 41 and the teeth 42 are composed of a core 45 and an insulator 46. The core 45 is a magnetic body and is formed, for example, by stacking steel plates in the direction of the rotation axis J. The insulator 46 is, for example, an insulating resin molded product. Most of the surfaces of the teeth 42 and the yoke 41 of the core 45 are covered with an insulator 46.

  A slot 47 (space) having a rectangular cross section viewed from the direction of the rotation axis J is formed between two teeth 42 adjacent in the circumferential direction. The coil 44 is formed by winding the electric wires 50 around the individual teeth 42 while passing the electric wires 50 through the slots 47 (concentrated winding).

  The electric wire 50 to be used is an ordinary electric wire having a circular cross section, and the surface thereof is covered with an insulating thin film. The electric wires 50 are wound in layers on the teeth 42 while being aligned at the same pitch (aligned winding). The electric wires 50 of each layer are wound in a state of being overlapped and aligned with the electric wires 50 wound on the inner side until reaching the outermost layer.

  As a result, the outer peripheral surface of the coil 44 becomes flat, and the outer peripheral surfaces of two adjacent coils 44 located in the same slot 47 are positioned in parallel to each other with a slight gap therebetween.

  As shown in FIG. 3, the teeth 42 are formed in a tapered shape, and both side surfaces 42 r and 42 l of the teeth 42 facing the slot 47 are gradually symmetrical from the side of the yoke 41 toward the protruding end. Inclined to approach. Therefore, both end surfaces 42t and 43u of the tooth 42 facing the direction of the rotation axis J are gradually reduced in width from the yoke 41 side toward the protruding end.

  On the four corners of the teeth 42 constituted by the side surfaces 42r, 42l and the end surfaces 42t, 43u, guide portions 48 having a plurality of concave and convex shapes are formed along the edges. The guide portion 48 is provided to guide the electric wire 50 to a predetermined winding position. In the case of the guide portion 48, the electric wire 50 is positioned by fitting the electric wire 50 into the recess.

  As shown in FIG. 4, the electric wire 50 is wound in order from the yoke 41 side of the tooth 42.

  Specifically, when the electric wire 50 starts to pass through the slot 47 on the right side of the tooth 42 from above the tooth 42, the electric wire 50 is first placed at the base portion of the tooth 42 so as to be positioned closest to the yoke 41 side. The right side surface 42r, the lower end surface 42u, and the left side surface 42l are wound in this order.

  Unless otherwise specified, the directions such as up, down, left, and right will be described with reference to FIGS. 3 and 4 for the sake of convenience.

  Then, when the electric wire 50 comes to the upper end surface 42t again, the electric wire 50 is wound around the upper end surface 42t of the tooth 42 while being shifted obliquely so as to be adjacent to the electric wire 50 wound along the right side surface 42r. . Thereafter, as shown in FIG. 5, the right side surface 42r, the lower end surface 42u, and the left side are arranged along the previously wound electric wire 50 so that the electric wire 50 is positioned closest to the yoke 41 as in the previous case. It is wound in the order of the surface 42l. Thereafter, in the same manner, the electric wires 50 are wound around the teeth 42 while being aligned at the same pitch until reaching the tip of the teeth 42. By doing so, the first layer of the coil 44 is formed.

  However, in the case of tapered teeth, just by forming the guide portion 48 in accordance with the pitch of the electric wires 50 as in the case of prismatic teeth, adjacent electric wires 50 collide with each other and cannot be wound properly.

  In this regard, with reference to FIG. 6, when the electric wire 50 is wound at a pitch at which the electric wires 50 are parallel, the teeth 42 are inclined, so that the electric wires are placed on the right side surface 42 r that is the winding start side of the teeth 42. When winding 50, the part (mesh part) which overlaps with the electric wire 50 wound previously and collides occurs. As a result, it is difficult to position the electric wire 50, for example, the electric wire 50 rides on the guide portion 48, and there is a possibility that the aligned state of the electric wire 50 is broken.

  Therefore, in this motor 1, the arrangement of the first-layer electric wires 50 (hereinafter also simply referred to as electric wires 50f) is devised so that even the tapered teeth 42 can be stably aligned and wound.

  In FIG. 7, the arrangement | positioning state of the electric wire 50f which looked at the direction of the rotating shaft J from the upper end surface 42t side is shown.

  The electric wire 50f is wound around the tooth 42 so that the electric wire 50f moves to the next winding position, and a group of portions facing the direction of the rotation axis J in the electric wire 50f is centered on the center line C of the tooth 42. In contrast, they extend in a slanted manner and are arranged non-parallel to each other with a gap.

  Specifically, from the right side 42r to the lower end surface 42u, the left side surface 42l, and the upper end surface 42t, the electric wire 50f wound around the teeth 42 along each of these surfaces is taken as one turn, and the first winding is taken as the first coil. It is assumed that one turn wound subsequent to the element 51a and the first coil element 51a is a second coil element 51b, and the third coil elements 51c,.

  In such a case, a portion of the first coil element 51a located on the upper end surface 42t (this portion is also referred to as a transition portion 52) is separated from the transition portion 52 of the second coil element 51b by a slight gap s. The transition part 52 of the second coil element 51b is located with a slight gap s1 from the transition part 52 of the third coil element 51c. Similarly, the transition part 52 of the fourth coil element 51d and the like is located with a slight gap s1 from the transition part 52 of each adjacent coil element 51 (generally using reference numeral 51).

  Specifically, the pitch P of the electric wires 50f constituting each coil element 51, specifically, the distance between the centers of the adjacent electric wires 50f on the left side surface 42l and the right side surface 42r of the tooth 42 is It is set larger than the outer diameter A of 50 (P> A).

  By providing the gap s1, there is no portion where the electric wire 50f collides. As a result, the electric wire 50f can be properly guided by the guide portion 48, and the electric wire 50f can be positioned stably.

  The inclination of the transition part 52 of the second coil element 51b is larger than the inclination of the transition part 52 of the first coil element 51a, and the inclination of the transition part 52 of the third coil element 51c is the second coil element 51b. Which are larger than the inclination of the transition part 52 and are not parallel to each other. Similarly, the transition part 52 of the fourth coil element 51d and the like is larger than the inclination of the transition part 52 of the previous coil element 51 and is not parallel to each other.

  By arranging the transition portion 52 of the electric wire 50f in this way, stable aligned winding can be realized even with the tapered teeth 42 while keeping the pitch P of the electric wire 50f constant.

  That is, as shown in FIG. 8, the electric wires 50f of the coil elements 51 on the lower end surface 42u are arranged in parallel to each other with a gap s2 in a state of extending perpendicularly to the center line C of the teeth 42. As shown in FIG. 9, the electric wires 50f of the coil elements 51 on the right side 42r and the left side 42l are also arranged in parallel to each other with a gap s3.

  Therefore, each coil element 51 is wound around the tooth 42 without contacting the front and rear adjacent coil elements 51, so that stable aligned winding can be realized.

  However, since the space factor decreases as the gaps s1, s2, and s3 become larger, the pitch P is preferably as small as possible.

  Then, the setting which can obtain the optimal pitch P based on geometric conditions was examined.

  The setting will be described with reference to FIGS. FIG. 10 shows the electric wire 50f located on the left side 42l side as viewed from the direction of the rotation axis J.

  First, δ is an inclination angle of the left side surface 42l and the right side surface 42r of the tooth 42 with respect to the center line C. As shown in FIG. 7, in the first coil element 51a located closest to the yoke 41 and in contact with the inner peripheral surface of the yoke 41, the two electric wires facing left and right across the teeth 42 Let the distance between the centers of 50f be W.

  At that time, the pitch P of the electric wire 50f and the outer diameter A of the electric wire 50f are set so as to satisfy the following first relational expression.

  P ≧ A / Cos (θ + δ), where θ = ArcSin (A / W): first relational expression

  By setting the pitch P to satisfy the first relational expression, stable aligned winding can be easily realized even with the tapered teeth 42. Since the gap s between the coil elements 51 can be reduced, it is preferable to employ a small pitch P.

  For example, if the pitch P is set so that the equation is established by the first relational expression, the minimum pitch P can be obtained. Specifically, as shown in FIG. 11, the adjacent electric wires 50f on the left side 42l viewed from the direction of the rotation axis J, that is, the winding side of the electric wires 50f (the opposite side to the winding start side) are in point contact with each other. It should be set so that.

  However, since various conditions are calculated | required by the specifications of the motor 1, such as the outer diameter A of the electric wire 50f, the number of slots S, etc., it can set suitably in the range with which the 1st relational expression is satisfy | filled.

  The value of W may be approximated using each numerical value that specifies the configuration of the stator 4.

  Specifically, the number of slots 47 is S, and the diameter of the inner peripheral surface of the yoke 41 is D (see FIG. 2). As shown in FIG. 12, the ratio of the width Lt of the teeth 42 to the width Ls of the slots 47 on the inner peripheral surface of the yoke 41 is K.

  In such a case, the value of W is approximated using the following second relational expression.

  W≈π × D / (2 × S) × K + A: second relational expression

  If it does so, since the setting of the optimal pitch P can be obtained from each condition of the stator 4 and the outer diameter of the electric wire 50f, the design of the stator 4 becomes easy.

  Specifically, when the stator 4 having the tapered teeth 42 is manufactured, the correspondence between the pitch P and the number of slots S is obtained based on the first relational expression and the second relational expression, and then the correspondence relation is obtained. Based on the above, the pitch P and the number of slots S according to the specifications of the motor 1 may be set.

  FIG. 13 is a graph showing the correspondence between the pitch P and the slot number S. A solid line and a broken line indicate two correspondences having the same value of A but different values of D and K described above.

  As shown in FIG. 13, even if the outer diameter A of the electric wire 50f is the same, the minimum value of the pitch P differs depending on the number of slots S. Therefore, when the number of slots S is set in advance, the number of slots S is the smallest. The value pitch P is preferably set.

  In particular, when the number of slots S can be selected, it is preferable to select the number of slots S at which the pitch P is the minimum value.

  As shown in FIG. 13, the function curve indicating the correspondence relationship between the pitch P and the number of slots S has a minimum value, and there are the number of slots S at which the pitch P is minimum (in the example shown, around 20). Therefore, based on such a correspondence relationship, by selecting the number of slots S at which the pitch P is the minimum value and setting the pitch P to the minimum value, while realizing stable aligned winding with the tapered teeth 42, The pitch P can be optimized, and the space factor of the electric wire 50f can be improved.

  In addition, the motor according to the present invention is not limited to the above-described embodiment, and includes various other configurations.

  For example, in the embodiment, directions such as up, down, left, and right are used for convenience of explanation, but these directions are only examples. For example, the electric wire 50f may start to be wound from the left side surface 42l side of the tooth 42, or may be wound from below the tooth 42.

  The stator core may be formed by connecting a plurality of divided cores.

DESCRIPTION OF SYMBOLS 1 Motor 2 Rotor 4 Stator 41 Yoke 42 Teeth 42t Upper end surface 42u Lower end surface 42r Right side surface 42l Left side surface 44 Coil 46 Insulator 47 Slot 48 Guide part 50 Electric wire J Rotating shaft C Center line

Claims (6)

A rotor in which a rotor rotating around a rotation axis is arranged inside a stator,
The stator is
A cylindrical yoke,
A plurality of teeth projecting radially from the inner peripheral surface of the yoke toward the rotation axis;
A plurality of coils formed by winding a wire around each of the teeth while passing through a slot formed between adjacent teeth;
With
Both side surfaces of the teeth facing the slot are symmetrically inclined so as to gradually approach from the yoke side toward the protruding end,
The electric wire of the first layer is wound around the teeth in order from the yoke side in an aligned state while being guided by a guide portion provided on the teeth.
Seen from the direction of the rotation axis,
The first-layer electric wires facing one of them are arranged parallel to each other with a gap in a state extending perpendicular to the center line of the teeth,
The motor of the first layer facing the other side is arranged in a non-parallel manner with a gap in a state where the electric wire of the first layer extends while being inclined with respect to the center line. The motor according to claim 1,
A motor set so that P> A, where A is the outer diameter of the electric wire and P is the pitch of the first layer electric wire. The motor according to claim 2,
The inclination angle of each side surface of the teeth with respect to the center line is δ, and the distance between the centers of the two first-layer electric wires that are located closest to the yoke and are opposed to each other with the teeth interposed therebetween is W. When
P ≧ A / Cos (θ + δ), where θ = ArcSin (A / W). The motor according to claim 3, wherein
When the number of the slots is S, the diameter of the inner peripheral surface of the yoke is D, and the ratio of the width of the teeth to the width of the slot on the inner peripheral surface of the yoke is K,
A motor in which an approximate value of π × D / (2 × S) × K + A is used for the value of W. A manufacturing method for manufacturing the motor according to claim 1,
The outer diameter of the electric wire is A, the pitch of the electric wire of the first layer is P, the inclination angle of each side surface of the tooth with respect to the center line is δ, and it is located closest to the yoke side and sandwiches the tooth. The distance between the centers of the two wires of the first layer facing each other is W, the number of the slots is S, the diameter of the inner peripheral surface of the yoke is D, and the distance on the inner peripheral surface of the yoke is When the ratio of the width of the teeth to the width of the slot is K,
P = A / Cos (θ + δ), where θ = ArcSin (A / W), W≈π × D / (2 × S) × K + A
A first step of obtaining a correspondence relationship between the pitch P of the first-layer electric wires and the number S of slots based on a relational expression satisfying
A second step of setting the pitch P and the number S of slots based on the correspondence relationship;
Manufacturing method. It is a manufacturing method of Claim 5, Comprising:
In the second step, the number of slots S is set to the number of slots where the pitch P is a minimum value.

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