JP2020171136A - Stator, motor and wiper motor - Google Patents

Abstract

To provide a stator, a motor, and a wiper motor capable of improving the winding occupancy rate and motor characteristics while preventing winding collapses and rattling, and reducing the size of the winding.SOLUTION: The stator includes a winding group 95 inserted into a slot 90 and having a plurality of windings 24 arranged in a plurality of stages in the radial direction. The windings 24 in the winding group 95 are arranged so that the number of the third stage located on the innermost side in the radial direction is one less than the number of the first and second stages in respective stages, and the number of windings 24 in the first and second stages is the same. In the first and second stages, the windings 24 of each stage are aligned in the circumferential direction and the radial direction so as to contact only one of the corresponding windings 24 of different stages, and the third stage of the winding 24 is arranged between the windings 24 adjacent to each other in the circumferential direction in the other stages.SELECTED DRAWING: Figure 6

Description

The present invention relates to a stator, a motor, and a wiper motor.

The motor stator comprises a plurality of windings housed in a slot and wound around a teeth. When the winding is energized, a magnetic field is generated in the stator, and a magnetic attraction or repulsion is generated between the magnetic field and the rotor to rotate the rotor.
Further, among the motors, there is a so-called IPM (Interior Permanet Magnet) motor in which a permanent magnet is embedded in the rotor core of the rotor. Further, there is a motor using reluctance torque (see, for example, Patent Document 1). In such a motor, the windings of the stator are often configured by a distributed winding method, and the number of windings of the windings wound in the same direction is odd.

Further, in the motor, the winding collapse of the winding in the slot greatly affects the characteristics of the motor. For this reason, for example, a technique for preventing winding collapse of windings by arranging the windings so as to be stacked in a radial direction is disclosed (see, for example, Patent Document 2). Further, a technique for forming a stepped portion on the teeth of the stator to prevent the winding from unwinding or rattling is disclosed (see, for example, Patent Document 3).

Japanese Unexamined Patent Publication No. 2009-033925 Japanese Unexamined Patent Publication No. 2006-345650 International Publication No. 2008/044703

However, in Patent Document 2 described above, as the wire diameter of the winding increases, the number of windings of the winding decreases, and the space factor decreases. In particular, when the windings are configured by the distributed winding method as in Patent Document 1 and the number of windings of the windings wound in the same direction is an odd number, the space factor is significantly reduced and the motor characteristics are deteriorated. There was a possibility that it would end up. If the slot is enlarged in order to improve the motor characteristics, the diameter of the motor may be increased by this amount.
Further, in the above-mentioned Patent Document 3, there is a problem that the slot space itself becomes small and it is difficult to improve the motor characteristics.

Therefore, the present invention provides a stator, a motor, and a wiper motor that can improve the space factor of the winding, improve the motor characteristics, and can be miniaturized while preventing the winding from unwinding and rattling. ..

In order to solve the above problems, the stator according to the present invention includes an annular stator core, a plurality of teeth protruding inward in the radial direction from the inner side surface of the stator core, and arranged along the circumferential direction. Two, including a slot formed between the teeth adjacent to each other and at least one winding group inserted into the slot and having a plurality of windings arranged in a plurality of stages in the radial direction. When the above winding groups are provided, the winding groups are arranged side by side in the radial direction, and the windings in the winding group arranged at least in the radial direction are each stage. Of these, the number of the innermost tiers located on the innermost side in the radial direction is one less than the number of the other tiers, and the number of the windings of the other tiers is the same. In each stage, the windings of each stage are aligned in the circumferential direction and the radial direction so as to contact only one of the corresponding windings of different stages, and the winding of the innermost stage. The wire is characterized in that it is arranged between the windings adjacent to each other in the circumferential direction in the other stage.

In the above configuration, the teeth have a plurality of the winding groups, and the teeth correspond to the innermost stage of the winding group excluding the innermost winding group in the radial direction among the plurality of winding groups. A convex portion may be provided at the position where the coil is formed so as to project toward the winding at the innermost stage.

In the above configuration, the teeth may have an insulator that covers the teeth and secures insulation between the teeth and the winding, and the insulator may have the convex portion.

In the above configuration, the windings are inserted into the slots in a distributed winding manner, two winding groups are arranged in each slot, the other stages are two stages, and 1 The number of the windings in the stage may be two, and the number of the windings in the innermost stage may be one.

In the above configuration, the teeth include a tooth body extending along the radial direction, a step portion formed at the radial inner end of the tooth body and larger than the circumferential width at the radial inner end of the tooth body. The winding of the innermost stage is arranged between the stepped portions that are formed at the radial inner end of the stepped portion and extend along the circumferential direction and are adjacent to each other in the circumferential direction. You may.

In the above configuration, the length of the step portion in the longitudinal direction when viewed from the axial direction of the stator core may be smaller than the wire diameter of the winding.

The motor according to the present invention is arranged in a motor case in which the stator described above and the outer peripheral surface of the stator core are fitted and the stator core is fixed, and inside the stator in the radial direction, and rotates with respect to the stator. It is characterized by being provided with a freely provided rotor.

The wiper motor according to the present invention is characterized in that the motor described above is used for a wiper device mounted on a vehicle.

According to the present invention, the innermost winding can be stacked with respect to the windings of other stages, and the space factor can be improved. Further, since the other stages are arranged in the circumferential direction and the radial direction, it is possible to prevent the number of windings from being reduced as compared with the case of bale stacking. Therefore, the motor characteristics can be improved.

The perspective view of the wiper motor in embodiment of this invention. A cross-sectional view taken along the line AA of FIG. FIG. 5 is a cross-sectional view taken along the radial direction of the stator and rotor according to the first embodiment of the present invention. B part enlarged view of FIG. The figure which developed the teeth of the stator in the 1st Embodiment of this invention. The figure which enlarged a part of the part corresponding to the teeth of FIG. FIG. 5 is a sectional view taken along the radial direction of the stator and rotor according to the second embodiment of the present invention.

Next, an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
<Wipe motor>
FIG. 1 is a perspective view of the wiper motor 1. FIG. 2 is a cross-sectional view taken along the line AA of FIG.
As shown in FIGS. 1 and 2, the wiper motor 1 is mounted on a vehicle, for example, and serves as a drive source for a wiper device 100 for wiping window glass (neither of which is shown). The wiper motor 1 includes a motor unit (corresponding to the motor in the claim) 2, a deceleration unit 3 that decelerates and outputs the rotation of the motor unit 2, and a controller unit 4 that controls the drive of the motor unit 2. ..
In the following description, the term "axial direction" refers to the rotation axis C direction of the shaft 31 of the motor unit 2, the term "circumferential direction" refers to the circumferential direction of the shaft 31, and the term "diameter direction" refers to the shaft 31. It shall refer to the radial direction of.

<Motor section>
The motor unit 2 is provided in the motor case 5, a substantially cylindrical stator 8 housed in the motor case 5, and a rotor provided inside the stator 8 in the radial direction and rotatably provided with respect to the stator 8. 9 and. The motor unit 2 is a so-called brushless motor that does not require a brush to supply electric power to the stator 8.

<Motor case>
The motor case 5 is made of a material having excellent heat dissipation, such as aluminum die casting. The motor case 5 includes a first motor case 6 and a second motor case 7 which are configured to be rotatable in the axial direction. The first motor case 6 and the second motor case 7 are each formed in a bottomed tubular shape.
The first motor case 6 is integrally molded with the gear case 40 so that the bottom portion 10 is joined to the gear case 40 of the reduction gear portion 3. A through hole 10a through which the shaft 31 of the rotor 9 can be inserted is formed at substantially the center of the bottom portion 10 in the radial direction.

An outer flange portion 16 projecting outward in the radial direction is formed in the opening 6a of the first motor case 6. An outer flange portion 17 projecting outward in the radial direction is formed in the opening 7a of the second motor case 7. The outer flange portions 16 and 17 are butted against each other to form a motor case 5 having an internal space. The outer peripheral surface of the stator 8 is fitted in the internal space of the motor case 5 and on the inner peripheral surfaces of the first motor case 6 and the second motor case 7. In the stator 8, the outer peripheral surface of the stator 8 may be fitted only to the first motor case 6.

<Stator>
FIG. 3 is a cross-sectional view taken along the radial direction of the stator 8 and the rotor 9. FIG. 4 is an enlarged view of part B of FIG.
As shown in FIGS. 2 to 4, the stator 8 is integrated with a cylindrical stator core 21 having a substantially annular cross-sectional shape along the radial direction and a stator core 21, and protrudes inward in the radial direction from the stator core 21. A plurality of (for example, 24 in this embodiment) teeth 22 are provided. The stator core 21 and the teeth 22 are formed, for example, by laminating a plurality of metal plates in the axial direction. The stator core 21 is not limited to the case where a plurality of metal plates are laminated in the axial direction, and may be formed, for example, by pressure molding soft magnetic powder.

The teeth 22 are formed at the radial inner end of the teeth main body 91 and the teeth main body 91 protruding along the radial direction from the inner peripheral surface of the stator core 21, and is wider than the circumferential width W1 at the radial inner end of the teeth main body 91. The large stepped portion 92 and the flange portion 93 formed at the radial inner end of the stepped portion 92 and extending along the circumferential direction are integrally molded. Slots 90 are formed between the teeth 22 adjacent to each other in the circumferential direction. A plurality of windings 24 are inserted into each slot 90. The detailed configuration of the winding 24 will be described later.

The tooth body 91 is formed so that the width in the circumferential direction gradually decreases from the stator core 21 side toward the inner end in the radial direction. As a result, the width W2 in the circumferential direction of the slot 90 becomes uniform in the entire radial direction.
The step portion 92 is formed from the tooth body 91 via the step surface 92a. The stepped surface 92a is formed slightly obliquely so as to gradually inward in the radial direction toward the outside in the circumferential direction. A round chamfered portion 92b is formed at a corner portion on the outer side of the stepped surface 92a in the circumferential direction. The step portion 92 is formed so that the width W3 in the circumferential direction gradually becomes narrower toward the inside in the radial direction. The width W3 of the step portion 92 in the circumferential direction maximizes the position of the round chamfered portion 92b.

The flange portion 93 is formed so that the width W4 in the circumferential direction is larger than the width W3 in the circumferential direction of the step portion 92. A round chamfered portion 93a is also formed at a corner portion where the step portion 92 and the flange portion 93 are connected.
Further, the teeth 22 are the side surfaces of the teeth body 91 and the step portion 92 in each circumferential direction, each axial end surface, the round chamfered portion 93a of the collar portion 93, and the axial end surface of the flange portion 93, and are round chamfered. It has an insulator 23 that covers a position corresponding to the portion 93a. The winding 24 inserted into the slot 90 is insulated from the teeth 22 by the insulator 23.

<Composition of winding>
FIG. 5 is a developed view of the teeth 22 of the stator 8. FIG. 6 is an enlarged view of a part of the portion corresponding to the teeth 22 in FIG. The wire type of the winding 24 shown in FIG. 5 corresponds to the wire type of the winding 24 shown in FIG. Further, in FIG. 5, each tooth 22 is numbered so as to be in order in the circumferential direction. In FIG. 5, the space between the adjacent teeth 22 in the circumferential direction corresponds to the slot 90. In FIG. 5, magnetic poles (N pole, S pole) are shown above the stator 8. In the first embodiment, the number of magnetic poles is 4 (details will be described later).

As shown in FIGS. 5 and 6, a plurality of windings 24 (for example, 10 in this embodiment) are inserted in each slot 90. Of the plurality of windings 24, a predetermined number of windings 24 (for example, 5 in the present embodiment) are provided on both sides with a predetermined number (for example, 4 in the present embodiment) of slots 90 in between. Those inserted in the located slots 90 are connected to each other via an end coil 94. The number of end coils 94 is the same as the number of windings 24, and the corresponding windings 24 between the predetermined slots 90 are connected to each other separately. As a result, a predetermined number of windings 24 constitute one winding group 95 wound between the predetermined slots 90.

In the present embodiment, the number of magnetic poles is four, and one winding group 95 is wound between the slots 90 located on both sides of the total of 24 slots 90 with the four slots 90 in between. Therefore, the winding 24 is wound around the stator 8 by a distributed winding method. Therefore, of the 10 windings 24 inserted in one slot 90, 5 windings 24 form one winding group 95. That is, there are two winding groups 95 in one slot 90. The windings 24 forming the two winding groups 95 are connected to the windings 24 inserted into separate slots 90 via end coils 94. Further, the two winding groups 95 are arranged side by side in the radial direction in one slot 90. Hereinafter, of the two winding groups 95, the winding group 95 arranged on the outer side in the radial direction is referred to as the outer winding group 95o, and the winding group 95 arranged on the inner side in the radial direction is referred to as the inner winding group 95i. May be done.

In the outer winding group 95o and the inner winding group 95i, five windings 24 are arranged in three stages, respectively. Assuming that the first step, the second step, and the third step are in order from the outside in the radial direction, two windings 24 are arranged in each of the first step and the second step (corresponding to the other steps in the claim). The number of windings 24 in the first and second stages is the same. The third stage (corresponding to the innermost stage in the claim) is a stage located on the innermost side in the radial direction, and one winding 24 is arranged. The number of windings 24 in the third stage is one less than the number of windings 24 in the first and second stages.

The windings 24 arranged in the first and second stages are aligned in the circumferential direction and the radial direction. In other words, the windings 24 of each stage are arranged in a row in the circumferential direction. In the first-stage winding 24 and the second-stage winding 24, the corresponding windings 24 are arranged side by side in the same linear shape in the radial direction. Therefore, in the first and second stages, the windings 24 of each stage are in contact with each other only one of the corresponding windings 24 of the other stages.
On the other hand, the windings 24 arranged in the third stage are arranged between the windings 24 adjacent to each other in the circumferential direction in the second stage. That is, the second-stage winding 24 and the third-stage winding 24 are stacked in a bale.

Here, the wire diameter of the winding 24 is about 1/2 or slightly smaller than 1/2 with respect to the width W2 in the circumferential direction of the slot 90. Therefore, the windings 24 of the first and second stages are prevented from being unwound or rattling. Further, the third-stage winding 24 is stacked on the second-stage winding 24, and the winding collapse and rattling of the third-stage winding 24 are prevented.
Further, since the outer winding group 95o and the inner winding group 95i are arranged side by side in the radial direction in one slot 90, the third-stage winding 24 and the inner winding group of the outer winding group 95o are arranged. The winding 24 of the first stage of 95i is stacked in a bale. The third-stage winding 24 of the inner winding group 95i is arranged between the stepped portions 92 adjacent to each other in the circumferential direction.

Here, the width W3 of the step portion 92 in the circumferential direction is such that the distance K between the step portions 92 adjacent to each other in the circumferential direction is the same as or slightly smaller than the wire diameter of the winding 24. The length L of the step portion 92 in the longitudinal direction when viewed from the axial direction is smaller than the wire diameter of the winding 24. Therefore, the third-stage winding 24 in the inner winding group 95i is arranged between the stepped portions 92 adjacent to each other in the circumferential direction without rattling.

The distance K between the stepped portions 92 adjacent to each other in the circumferential direction and the radial length L of the stepped portions 92 include the case where the teeth 22 is covered with the insulator 23 and the thickness of the insulator 23. It shall be said. In the present embodiment, since the teeth 22 are covered with the insulator 23, the width W3 of the step portion 92 in the circumferential direction is between the step portions 92 adjacent to each other in the circumferential direction in the state where the teeth 22 is covered with the insulator 23. The interval K is the same as or slightly smaller than the wire diameter of the winding 24. With the teeth 22 covered with the insulator 23, the length L in the longitudinal direction of the step portion 92 when viewed from the axial direction, that is, the length L in the longitudinal direction when viewed from the axial direction at the portion corresponding to the step portion 92 of the insulator 23 ( The length L of the alternate long and short dash line in FIG. 6) is smaller than the wire diameter of the winding 24. On the other hand, when the insulator 23 is not attached to the teeth 22, the width W3 in the circumferential direction of the step portion 92 itself and the length L in the longitudinal direction when viewed from the axial direction are based on the interval K and the wire diameter of the winding 24. Set.

The winding 24 (winding group 95) configured in this way is connected to the controller 4 in the form of pulling out the terminal from the stator 8. The winding 24 generates a magnetic field for rotating the rotor 9 by the power supply from the controller unit 4.

<Rotor>
As shown in FIG. 3, the rotor 9 is fitted and fixed to the shaft 31 integrally formed with the worm shaft 44 (see FIG. 2) constituting the reduction gear 3 and the outer peripheral surface of the shaft 31, and the axial center of the shaft 31. A substantially cylindrical rotor core 32 having a rotation axis C, and a plurality of resin magnets 33a to 33d arranged in the rotor core 32 are provided.

The rotor core 32 is formed, for example, by laminating a plurality of metal plates in the axial direction. The rotor core 32 is not limited to the case where a plurality of metal plates are laminated in the axial direction, and may be formed, for example, by pressure molding soft magnetic powder.
A through hole 32a is formed along the axial direction at the center of the rotor core 32 in the radial direction. The shaft 31 is fixed to the through hole 32a by press fitting or the like. As a result, the shaft 31 and the rotor core 32 rotate integrally. The rotor core 32 is held in a state where the outer peripheral surface faces the inner peripheral surface of the stator core 21 in the radial direction via a predetermined air gap G.

The rotor core 32 is formed with four layers of slits 35a to 35d arranged in the radial direction in each of the circumferential angle regions of 1/4 circumference. The slits 35a to 35d are formed along the flow of the interlinkage magnetic flux formed when the winding 24 is energized. That is, each of the slits 35a to 35d is curved so that the center in the circumferential direction is located most radially inward (so as to have a convex shape toward the inward in the radial direction). As a result, the rotor core 32 is formed with a direction in which the magnetic flux easily flows and a direction in which the magnetic flux does not easily flow. Both ends of the slits 35a to 35d in the circumferential direction extend to the vicinity of the outer peripheral surface of the rotor core 32. Therefore, the peripheral length becomes longer as the slits 35a to 35d are located inward in the radial direction. Under such a configuration, the rotor core 32 is configured to have four poles, and four layers of slits 35a to 35d are formed per pole (a circumferential angle region around 1/4 of the rotor core 32).

In each of the slits 35a to 35d, resin magnets 33a to 33d curved so as to correspond to the shapes of the slits 35a to 35d are provided. The resin magnets 33a to 33d are provided so that a slight gap 34 is formed at both ends of the corresponding slits 35a to 35d in the circumferential direction. The gap 34 functions as a flux barrier for preventing the magnetic fluxes of the resin magnets 33a to 33d from leaking in a predetermined direction.

The resin magnets 33a to 33d are made of so-called bond magnets having polar anisotropy in which a magnetic material (for example, a rare earth element such as neodymium or samarium) and a non-magnetic resin material are mixed. The resin magnets 33a to 33d are formed so as to have different poles in the radial direction. The resin magnets 33a to 33d arranged in the slits 35a to 35d of the same magnetic pole are arranged so that the magnetic poles are oriented in the same direction. Further, the resin magnets 33a to 33d arranged in the slits 35a to 35d of each pole are arranged so that the magnetic poles are in order in the circumferential direction. The resin magnets 33a to 33d may be formed by injecting the bond magnets into the slits 35a to 35d. By doing so, the gap 34 may be provided so as not to be formed between the slits 35a to 35d and the resin magnets 33a to 33d.

<Deceleration part>
Returning to FIGS. 1 and 2, the deceleration unit 3 includes a gear case 40 to which the motor case 5 is attached, and a worm deceleration mechanism 41 housed in the gear case 40. The gear case 40 is made of a material having excellent heat dissipation such as aluminum die casting. The gear case 40 is formed in a box shape having an opening 40a on one surface, and has a gear accommodating portion 42 for accommodating the worm reduction mechanism 41 inside. The side wall 40b of the gear case 40 is formed with an opening 43 for communicating the through hole 10a of the first motor case 6 and the gear accommodating portion 42 at a position where the first motor case 6 is integrally molded. ..

A substantially cylindrical bearing boss 49 is projected from the bottom wall 40c of the gear case 40. The bearing boss 49 rotatably supports the output shaft 48 of the worm reduction mechanism 41. A slide bearing (not shown) is provided on the inner peripheral surface of the bearing boss 49. An O-ring (not shown) is attached to the inner peripheral edge of the tip of the bearing boss 49. As a result, dust and water are prevented from entering from the outside to the inside through the bearing boss 49. A plurality of ribs 52 are provided on the outer peripheral surface of the bearing boss 49. As a result, the rigidity of the bearing boss 49 is ensured.

The worm reduction mechanism 41 housed in the gear accommodating portion 42 is composed of a worm shaft 44 and a worm wheel 45 meshed with the worm shaft 44. The worm shaft 44 is arranged coaxially with the shaft 31 of the motor unit 2. Both ends of the worm shaft 44 are rotatably supported by bearings 46 and 47 provided in the gear case 40. The end of the worm shaft 44 on the motor portion 2 side projects through the bearing 46 to the opening 43 of the gear case 40. The end of the protruding worm shaft 44 and the end of the shaft 31 of the motor portion 2 are joined, and the worm shaft 44 and the shaft 31 are integrated. The worm shaft 44 and the shaft 31 may be integrally formed by forming the worm shaft portion and the rotating shaft portion from one base material.

The worm wheel 45 meshed with the worm shaft 44 is provided with an output shaft 48 at the center of the worm wheel 45 in the radial direction. The output shaft 48 is arranged coaxially with the direction of the rotation shaft of the worm wheel 45. The output shaft 48 projects to the outside of the gear case 40 via the bearing boss 49 of the gear case 40. A spline 48a that can be connected to an electrical component (not shown) is formed at the protruding tip of the output shaft 48.

A sensor magnet (not shown) is provided at the center of the worm wheel 45 in the radial direction on a surface opposite to the side on which the output shaft 48 is projected. This sensor magnet constitutes one of the rotation position detection units 60 that detects the rotation position of the worm wheel 45. The magnetic detection element 61, which constitutes the other side of the rotation position detection unit 60, is provided on the controller unit 4 which is arranged to face the worm wheel 45 on the sensor magnet side (opening 40a side of the gear case 40) of the worm wheel 45. There is.

<Controller>
The controller unit 4 that controls the drive of the motor unit 2 includes a controller board 62 on which the magnetic detection element 61 is mounted, and a cover 63 provided so as to close the opening 40a of the gear case 40. The controller board 62 is arranged to face the sensor magnet side of the worm wheel 45 (the opening 40a side of the gear case 40).

The controller substrate 62 is a so-called epoxy substrate on which a plurality of conductive patterns (not shown) are formed. The winding 24 of the motor unit 2 is electrically connected to the controller board 62, and the terminals of the connector provided on the cover 63 (none of which are shown) are electrically connected to the controller board 62. In addition to the magnetic detection element 61, a power module (not shown) including a switching element such as a FET (Field Effect Transistor) that controls a current supplied to the winding 24 is mounted on the controller board 62. A capacitor (not shown) or the like that smoothes the voltage applied to the controller board 62 is mounted on the controller board 62.

The cover 63 that covers the controller substrate 62 configured in this way is made of resin. The cover 63 is formed so as to bulge slightly outward. The inner surface side of the cover 63 is a controller accommodating portion 56 for accommodating the controller board 62 and the like.
A connector (not shown) is integrally molded on the outer peripheral portion of the cover 63. This connector is formed so as to be fitted with a connector extending from an external power source (not shown). The controller board 62 is electrically connected to the terminals of this connector. As a result, the electric power of the external power source is supplied to the controller board 62.

Here, the controller board 62 energizes the winding 24 with an advance angle and a wide-angle energization with an electric angle θ of 121 ° to 180 °. The controller board 62 applies a drive current in which the fifth harmonic is superimposed to the winding 24.

A fitting portion 81 that is fitted with the end portion of the side wall 40b of the gear case 40 is formed so as to project from the opening edge of the cover 63. The fitting portion 81 is composed of two walls 81a and 81b along the opening edge of the cover 63. The end of the side wall 40b of the gear case 40 is inserted (fitted) between these two walls 81a and 81b. As a result, the labyrinth portion 83 is formed between the gear case 40 and the cover 63. The labyrinth portion 83 prevents dust and water from entering between the gear case 40 and the cover 63. The gear case 40 and the cover 63 are fixed by fastening bolts (not shown).

<Operation of wiper motor>
Next, the operation of the wiper motor 1 will be described.
In the wiper motor 1, the electric power supplied to the controller board 62 via the connector 11 is selectively supplied to each winding 24 of the motor unit 2 via a power module (not shown). Then, the current flowing through each winding 24 forms a predetermined interlinkage magnetic flux in the stator 8 (teeth 22). This interlinkage magnetic flux generates a magnetic attractive force or repulsive force (magnet torque) with the effective magnetic flux formed by the permanent magnet 33 of the rotor 9. The interlinkage magnetic flux also causes the rotor 9 to generate reluctance torque. As a result, the rotor 9 is continuously rotated.

The rotation of the rotor 9 is transmitted to the worm shaft 44 integrated with the shaft 31, and further transmitted to the worm wheel 45 meshed with the worm shaft 44. The rotation of the worm wheel 45 is transmitted to the output shaft 48 connected to the worm wheel 45. The wiper device 100 is driven by the output shaft 48.

The detection signal of the rotation position of the worm wheel 45 detected by the magnetic detection element 61 mounted on the controller board 62 is output to an external device (not shown). An external device (not shown) is a software functional unit that functions by executing a predetermined program by a processor such as a CPU (Central Processing Unit). The software function unit is an ECU (Electronic Control Unit) including a processor such as a CPU, a ROM (Read Only Memory) for storing a program, a RAM (Random Access Memory) for temporarily storing data, and an electronic circuit such as a timer. .. At least a part of the external device (not shown) may be an integrated circuit such as an LSI (Large Scale Integration).

An external device (not shown) controls the switching timing of a switching element or the like of a power module (not shown) based on the rotation position detection signal of the worm wheel 45, and controls the drive of the motor unit 2. The output of the drive signal of the power module and the drive control of the motor unit 2 may be executed by the controller unit 4 instead of an external device (not shown).

As described above, in the stator 8 in the first embodiment described above, two winding groups 95 (95o, 95i) are arranged in one slot 90. In each winding group 95, five windings 24 are arranged in three stages. Two windings 24 are arranged in each of the first stage and the second stage, and are arranged in alignment in the circumferential direction and the radial direction. In the third stage, one winding 24, which is one less than the first and second stages, is arranged. As a result, only a part of the windings 24 (only the second and third stages) constituting the winding group 95 are stacked.

Here, for example, if the windings 24 are to be stacked in a bale in the entire winding group 95, the first and third stages are set to one winding 24, or only the second stage is wound by one. It will be line 24. If the first and third stages are set to one winding 24, the number of windings 24 for one winding group 95 will decrease, and the space factor of the windings 24 will decrease. On the other hand, if only the second stage is to have one winding 24, the step portion 92 must be removed so that the two windings 24 can be arranged in the third stage in the inner winding group 95i. , The magnetic path inside the teeth 22 in the radial direction is narrowed.

Therefore, in the winding group 95, two windings 24 are arranged in each of the first and second stages, and one winding 24 is arranged in the third stage, and only a part of the windings is stacked. As a result, the space factor of the winding 24 can be improved while preventing the winding 24 from collapsing and rattling. In addition to this, since the step portion 92 can be formed on the teeth 22, the magnetic path of the teeth 22 can be sufficiently secured, and magnetic saturation can be suppressed. Therefore, the motor characteristics can be improved.

Of the windings 24 constituting the winding group 95, a part of the windings 24 is stacked in a bale so that all the windings 24 are aligned in the circumferential direction and the radial direction. The length in the radial direction can be shortened. That is, since there is a portion where the windings 24 of different stages are overlapped with each other when viewed from the circumferential direction, the length of the winding group 95 in the radial direction can be shortened. When two winding groups 95 (outer winding group 95o, inner winding group 95i) are arranged in one slot 90 as in the above-described embodiment, windings in different stages when viewed from the circumferential direction. There are a total of 3 locations where the 23 overlap. Therefore, the stator 8 can be miniaturized.

Among each stage of the winding group 95, the number of windings 24 of the third stage located on the innermost side in the radial direction is reduced by one as compared with the other stages (first stage and second stage). Therefore, the thickness of the stator core 21 in the radial direction can be sufficiently secured. That is, a sufficient magnetic path of the stator core 21 can be secured.

Here, for example, among each stage of the winding group 95, the number of windings 24 of the first stage located on the outermost side in the radial direction is compared with that of the other stages (second stage and third stage) to be 1. When the number is reduced, it is necessary to form, for example, a recess in the stator core 21 capable of accommodating the winding 24 in order to suppress the rattling of the winding 24 in the first stage. If the recess is formed in this way, the magnetic path of the stator core 21 is narrowed by this amount. However, in the first embodiment, the magnetic path of the stator core 21 can be sufficiently secured while preventing the winding 24 from being unwound or rattling, so that the motor characteristics can be improved more reliably.

For example, in the outer winding group 95o, the number of windings 24 of the first stage located on the outermost side in the radial direction is reduced by one as compared with the other stages (second and third stages). In the inner winding group 95i, when the number of windings 24 of the third stage located on the innermost side in the radial direction is reduced by one as compared with the other stages (first stage and second stage), the circumferential direction There are a total of two places where the windings of different stages overlap each other. Therefore, it becomes difficult to miniaturize the stator 8 as compared with the present embodiment, and it becomes impossible to sufficiently secure the magnetic path of the stator core 21.

Further, the width W3 of the step portion 92 in the circumferential direction is such that the distance K between the step portions 92 adjacent to each other in the circumferential direction is the same as or slightly smaller than the wire diameter of the winding 24. The length L of the step portion 92 in the longitudinal direction when viewed from the axial direction is smaller than the wire diameter of the winding 24. Therefore, the third-stage winding 24 in the inner winding group 95i is arranged between the stepped portions 92 adjacent to each other in the circumferential direction without rattling, and the winding 24 can be reliably prevented from collapsing or rattling.

The stepped surface 92a of the stepped portion 92 is formed so as to be gradually inclined inward in the radial direction toward the outside in the circumferential direction. A round chamfered portion 92b is formed at a corner portion on the outer side of the stepped surface 92a in the circumferential direction. The step portion 92 is formed so that the width W3 in the circumferential direction gradually becomes narrower toward the inside in the radial direction. The width W3 of the step portion 92 in the circumferential direction maximizes the position of the round chamfered portion 92b. The flange portion 93 is formed so that the width W4 in the circumferential direction is larger than the width W3 in the circumferential direction of the step portion 92. A round chamfered portion 93a is also formed at a corner portion where the step portion 92 and the flange portion 93 are connected. With this configuration, the gap formed between the teeth 22 and the winding 24 can be made as small as possible. Therefore, the space factor of the winding 24 can be more reliably improved, and the interlinkage magnetic flux generated by the winding 24 can be efficiently transmitted to the teeth 22.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. 7. In the same embodiment as in the first embodiment, the same reference numerals are given and the description thereof will be omitted.
FIG. 7 is an enlarged view of a part of the stator 8 corresponding to the teeth 22. FIG. 7 corresponds to FIG. 6 described above.
As shown in FIG. 7, in the second embodiment, the insulator 223 of the stator 8 has three stages at a position corresponding to the third stage winding 24 (one winding 24) in the outer winding group 95o. It has a convex portion 71 that projects toward the winding 24 of the eye. This point is different from the above-mentioned first embodiment.

The convex portion 71 is formed in a substantially semicircular shape with a cross section along the radial direction. The radius of curvature of the convex portion 71 is substantially the same as the radius of the winding 24. In the third-stage winding 24 in the outer winding group 95o, rattling in the circumferential direction is suppressed by the convex portion 71.

Therefore, according to the above-mentioned second embodiment, the same effect as that of the above-mentioned first embodiment can be obtained. In addition to this, the convex portion 71 can more reliably prevent the winding 24 from being unwound or rattling.

The present invention is not limited to the above-described embodiment, and includes various modifications of the above-described embodiment without departing from the spirit of the present invention.
For example, in the above-described embodiment, the case where the wiper motor 1 serves as a drive source for the wiper device 100 for wiping the window glass of the vehicle has been described. However, the configuration of the above-mentioned wiper motor 1 is not limited to this, and is used as a drive source for electrical components mounted on a vehicle (for example, a power window, a sunroof, an electric seat, etc.) and various other applications. Can be adopted.

In the above-described embodiment, the case where two winding groups 95 (outer winding group 95o, inner winding group 95i) are arranged in one slot 90 has been described. However, the present invention is not limited to this, and at least one winding group 95 may be arranged in one slot 90. Further, two or more winding groups 95 may be arranged in one slot 90.
For example, when three or more winding groups 95 are arranged in one slot 90, if the number of windings 24 in the third stage in the winding group 95 located at least on the innermost side in the radial direction is one. Good. The number of the third-stage windings 24 in all the winding groups 95 may be one.

In the above-described embodiment, the case where one winding group 95 has five windings 24 divided into three stages has been described. However, the present invention is not limited to this, and the winding group 95 may be formed by arranging a plurality of windings 24 in a plurality of stages in the radial direction. For example, when one winding group 95 is arranged by arranging six or more windings 24 in a plurality of stages in the radial direction, the winding 24 is the innermost stage located on the innermost side in the radial direction of each stage. The number of lines may be one less than the number of lines in other stages. Further, the number of windings 24 in the other stages may be the same. Further, in the other stages, the windings 24 of each stage may be aligned in the circumferential direction and the radial direction so as to come into contact with only one of the corresponding windings 24 of the different stages. Further, the winding 24 in the innermost stage may be arranged between the windings 24 adjacent to each other in the circumferential direction in the other stage and stacked in a bale.

In the above-described embodiment, the case where the teeth 22 is formed on the insulator 233 and has a convex portion 71 for preventing rattling of the third-stage winding 24 of the outer winding group 95o has been described. However, the present invention is not limited to this, and for example, the convex portion 71 may be formed directly on the tooth 22 that does not have the insulator 233.
The case where the convex portion 71 is formed in a substantially semicircular shape in a cross section along the radial direction has been described. However, the shape is not limited to this, and any shape may be used as long as it can prevent the winding 24 from rattling. For example, the shape of the cross section along the radial direction may be triangular or square.

In the above-described embodiment, the case where the winding 24 is wound around the stator 8 by the distributed winding method has been described. However, the present invention is not limited to this, and the above-described configuration of the stator 8 can be adopted even when the winding 24 is wound around the stator 8 by a lap winding method or a centralized winding method.

In the above-described embodiment, the case where the length L of the step portion 92 in the longitudinal direction when viewed from the axial direction is smaller than the wire diameter of the winding 24 has been described. However, the length L in the longitudinal direction of the step portion 92 when viewed from the axial direction is not limited to this, and the length L in the longitudinal direction of the step portion 92 is the third winding in the inner winding group 95i between the step portions 92 adjacent to each other at least in the circumferential direction. The wire 24 may be set to be insertable.

In the above-described embodiment, the case where the rotor 9 has a configuration utilizing the reluctance torque has been described. However, the present invention is not limited to this, and an IPM motor in which a magnet is simply embedded along the circumferential direction near the outer peripheral surface of the rotor core 32 or a so-called SPM (Surface Permanent Magnet) motor in which a magnet is provided on the outer peripheral surface of the rotor core 32. Also, the above-mentioned configuration of the stator 8 can be adopted.

1 ... Wiper motor, 2 ... Motor unit (motor), 5 ... Motor case, 6 ... 1st motor case, 7 ... 2nd motor case, 8 ... Stator, 9 ... Rotor, 21 ... Stator core, 22 ... Teeth, 23,233 ... Insulator, 24 ... Winding, 71 ... Convex part, 90 ... Slot, 91 ... Teeth body, 92 ... Step part, 93 ... Flange part, 95 ... Winding group, 95o ... Outer winding group, 95i ... Inner winding Group, 100 ... Wiper device

Claims (8)

With an annular stator core
A plurality of teeth projecting inward in the radial direction from the inner surface of the stator core and arranged along the circumferential direction,
Slots formed between the teeth adjacent to each other in the circumferential direction,
At least one winding group inserted into the slot and having a plurality of windings arranged in a plurality of stages in the radial direction.
With
When two or more of the winding groups are provided, the winding groups are arranged side by side in the radial direction.
The windings in the winding group arranged at least in the radial direction are arranged so that the number of the innermost stages located on the innermost side in the radial direction is one less than the number of the other stages. Coil,
The number of the windings in the other stages is the same.
In the other stages, the windings of each stage are aligned in the circumferential and radial directions so as to contact only one of the corresponding windings of the different stages.
A stator characterized in that the windings in the innermost stage are arranged between the windings adjacent to each other in the circumferential direction in the other stages. Having a plurality of the winding groups,
The teeth are placed on the windings in the innermost stage at a position corresponding to the innermost stage of the winding group excluding the innermost winding group in the radial direction among the plurality of winding groups. The stator according to claim 1, wherein the stator has a convex portion that protrudes toward the surface. The teeth have an insulator that covers the teeth and secures insulation between the teeth and the winding.
The stator according to claim 2, wherein the insulator has the convex portion. The winding is inserted into the slot in a distributed winding manner.
Two of the winding groups are arranged in each of the slots.
The other stage has two stages, and the number of windings in one stage is two.
The stator according to any one of claims 1 to 3, wherein the number of windings in the innermost stage is one. The teeth are
The tooth body extending along the radial direction and
A step portion formed at the radial inner end of the teeth body and larger than the circumferential width at the radial inner end of the teeth body.
A flange portion formed at the radial inner end of the step portion and extending along the circumferential direction,
Have,
The stator according to any one of claims 1 to 4, wherein the winding of the innermost stage is arranged between the stepped portions adjacent to each other in the circumferential direction. The stator according to claim 5, wherein the length of the step portion in the longitudinal direction when viewed from the axial direction of the stator core is smaller than the wire diameter of the winding. The stator according to any one of claims 1 to 6,
A motor case in which the outer peripheral surface of the stator core is fitted and the stator core is fixed,
A rotor arranged inside the stator in the radial direction and rotatably provided with respect to the stator.
A motor characterized by being equipped with. A wiper motor according to claim 7, wherein the wiper device mounted on a vehicle is used.

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