JP5977182B2 - motor - Google Patents

Description

  The present invention relates to a motor.

  2. Description of the Related Art Conventionally, as shown in Patent Document 1, for example, a magnetic plate having a laminated portion laminated on a core on an axial end face of the core and a facing portion extending radially outward from the laminated portion and facing a magnet in a radial direction A motor having an auxiliary rotor core in Patent Document 1 is known. Thus, by providing the facing portion that faces the magnet in the radial direction, it is possible to increase the amount of magnetic capture.

JP-A-5-284679

  By the way, in the motor as described above, in order to increase the amount of magnetic capture, it is preferable to make the axial length of the magnet longer than the facing portion. However, if the magnetism is too concentrated on the magnetic plate (opposing portion), the cogging torque tends to increase.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a motor capable of suppressing an increase in cogging torque while ensuring a magnetic intake amount.

A motor for solving the above problems includes a stator core having a plurality of core sheets stacked in the axial direction of a rotating shaft, a stator having armature windings provided on the stator core, and a field magnet facing the stator core in a radial direction. A rotor having a magnet, wherein the stator core includes a main core portion in which the core sheet having a tooth constituent portion around which the armature winding is wound is laminated in an axial direction; A magnetic plate provided at an axial end portion of the main core portion, and the magnetic plate includes a laminated portion laminated at an axial end portion of the main core portion, and an end portion on the rotor side of the laminated portion. The rotor has a rotor facing portion that extends outward in the axial direction and faces the rotor in the radial direction. The axial length of the rotor facing portion is h, and the radial length (plate thickness) of the rotor facing portion is t. ,Previous The axial extending length of the field magnet to the rotor opposing portion in the case of the s, h = t × K- 0.5s ( where coefficient K is 5 <range of K <6.3) so as to satisfy And the axial extension length s of the field magnet with respect to the rotor facing portion is configured to satisfy a range of 0 <s <2.0, and the radial length t of the rotor facing portion is wherein that is configured to be larger than the axial length of extension s of the field magnet to the rotor opposing portion.

According to this configuration, by configuring the motor so as to satisfy h = t × K−0.5 s (where the coefficient K is in the range of 5 <K <6.3), the range of the straight line X1 or less in FIG. Since the cogging torque is obtained, it is possible to provide the rotor facing portion within a range in which the increase in the cogging torque is suppressed, and to secure the amount of magnetic capture.

In the motor, the magnetic plate is preferably configured so that the range of the coefficient K satisfies 5.4 <K <6.3.
According to this configuration, by configuring the motor so that the range of the coefficient K satisfies 5.4 <K <6.3, a cogging torque in the range of the straight lines X2 to X1 in FIG. 12 can be obtained. While suppressing an increase in torque, the axial length of the rotor facing portion and the axially extending length of the field magnet can be ensured to ensure a magnetic intake amount.

In the motor described above, the teeth constituent portion extends in the radial direction to the rotor side, and is preferably formed so that a circumferential width becomes narrower toward the rotor side.
According to this configuration, since the teeth constituent portion extending to the rotor side is configured so that the circumferential width becomes narrower toward the rotor side, for example, in an inner rotor type motor, a space for the armature winding is ensured radially inside. can do. Further, in this case, since the tooth constituent portion is in contact with the magnetic plate, the magnetic saturation concentrated on the narrow portion on the rotor side of the tooth constituent portion can be relaxed to suppress magnetic saturation.

In the above motor, the field magnet of the rotor is preferably made of a ferrite magnet.
According to this configuration, the field magnet of the rotor is made of a relatively inexpensive ferrite magnet, which can contribute to cost reduction of the motor.

In the motor, it is preferable that the magnetic plate is provided on both axial sides of the main core portion.
According to this configuration, since the magnetic plates having the rotor facing portion are formed on both sides in the axial direction, it is possible to further increase the amount of magnetism captured while suppressing the axial length of the main core. In addition, since the armature winding can be arranged on the side opposite to the rotor of the rotor facing portion, the axial length can be suppressed.

  In the motor, the armature winding is inserted into a plurality of slots formed along the axial direction in the stator core, and a plurality of protrusions protruding in the axial direction from the slots are electrically connected to each other. The segment conductor is preferably configured such that the protruding portion of the segment conductor is opposed to the rotor facing portion of the magnetic plate in the radial direction.

  According to this configuration, since the projecting portion of the segment conductor in the axial direction faces the rotor facing portion of the magnetic plate in the radial direction, the facing surface of the stator core facing the rotor is secured by the rotor facing portion of the magnetic plate, and high output is achieved. While being planned, it is possible to suppress an increase in the size of the stator in the axial direction.

  The motor includes a first frame and a second frame that are provided on both sides in the axial direction of the stator core and sandwich the stator core in the axial direction, and the outer periphery of the stator core is between the first frame and the second frame. It is preferable that the surface is configured to be exposed to the outside.

  According to this configuration, when the stator core is sandwiched in the axial direction between the frames, the outer peripheral surface of the stator core is exposed, so that the heat of the stator core (stator) can be easily released to the outside. In addition, in the case of a stator in which the armature winding is composed of segment conductors, the space factor of the armature winding can be configured high, but it can easily generate heat, but the outer peripheral surface of the stator core extends from between each frame to the outside. Since it is exposed, it is preferable that the heat generated in the stator is easily released to the outside.

In the motor, it is preferable that the first and second frames are configured to sandwich the main core portion in the axial direction through the laminated portion of the magnetic plate.
According to this configuration, it is not necessary to reduce the size of the laminated portion of the magnetic plates so as not to interfere with each frame in the axial direction, so that a reduction in output can be suppressed.

In the motor, it is preferable that a thickness of the magnetic plate is set larger than a thickness of the core sheet.
According to this configuration, the thickness of the magnetic plate can be made thicker than the thickness of the core sheet so that the magnetism can be easily taken in through the magnetic plate, which can contribute to higher output.

  According to the motor of the present invention, it is possible to suppress an increase in cogging torque while securing a magnetic intake amount.

It is a schematic cross section of the motor of the embodiment. It is a top view of the stator of the same form. (A) is sectional drawing for demonstrating the magnetic board of the same form, (b) is a front view for demonstrating the rotor opposing part of the magnetic board of the same form. It is a disassembled perspective view of the stator core of the same form. It is a schematic cross section of the stator core of the same form. It is a top view which expands and shows the stator of the same form partially. It is a schematic cross section which shows the bending part of the segment conductor of the same form. It is a schematic cross section which expands and shows a part of motor of the same form. It is sectional drawing of the stator core of the structure using one piece of the magnetic plate of the same form. It is a graph which shows the relationship between the rotor opposing part of the magnetic plate of the same form, and cogging torque. It is a graph which shows the relationship between a rotor opposing part and cogging torque in case the axial direction extension length of a field magnet with respect to the rotor opposing part of the magnetic plate of the same form is 0.5 mm. It is a surface graph which shows the relationship between a rotor opposing part, a field magnet, and a cogging torque. It is the graph which showed the relationship between the rotor opposing part of the magnetic plate of the same form, and cogging torque in three dimensions. It is sectional drawing of the stator core of the structure which laminated | stacked two magnetic plates. It is sectional drawing of the stator core of the structure which laminated | stacked three magnetic plates. It is a schematic cross section which expands and shows the motor of another example partially. It is a schematic cross section which expands and shows the motor of another example partially.

Hereinafter, an embodiment of the motor will be described.
As shown in FIG. 1, the motor 10 of the present embodiment is configured by arranging a rotor 14 inside an annular stator 13 that is sandwiched between a rear frame 11 and a front frame 12 in the axial direction of the motor 10. A frame that holds the axial output side (a joint 63 side described later) of the motor 10 is a front frame 12, and a frame that holds an axially opposite output side is a rear frame 11. The frames 11 and 12 are fastened and fixed by through bolts 15 at positions on the outer peripheral side of the stator 13 so as not to be separated from each other.

[flame]
The rear frame 11 and the front frame 12 are formed of a metal material such as aluminum or steel. The rear frame 11 includes a substantially disc-shaped main body portion 11a, and a cylindrical stator holding portion 11b extending in the axial direction of the motor 10 from the outer peripheral edge of the main body portion 11a. One of the front frames 12 has a substantially similar configuration, and includes a substantially disc-shaped main body 12a and an annular stator holding portion 12b extending in the axial direction of the motor 10 from the outer peripheral edge of the main body 12a. Yes. Bearings 16 and 17 arranged coaxially are held at the radial center of the main body portions 11a and 12a of the respective frames 11 and 12, and a rotating shaft 18 of the rotor 14 is pivotally supported by the bearings 16 and 17. ing.

  Fastening and fixing portions 11c and 12c extending outward in the radial direction from a plurality of locations (for example, two locations) on the outer peripheral edge are formed on the main body portions 11a and 12a of the frames 11 and 12, respectively. In FIG. 1, only one fastening fixing portion 11c, 12c provided in the circumferential direction is illustrated. The same number of fastening fixing portions 11c on the rear frame 11 side and fastening fixing portions 12c on the front frame 12 side are provided, and are opposed to each other in the axial direction of the rotary shaft 18. Then, the fastening fixing portions 11 c and 12 c that make a pair are fastened and fixed by the through bolts 15, so that the frames 11 and 12 are fixed to each other with the stator 13 sandwiched therebetween.

[Stator]
The stator 13 includes an annular stator core 21 sandwiched between the stator holding portions 11 b and 12 b of the frames 11 and 12, and an armature winding 22 attached to the stator core 21.

  As shown in FIGS. 2 and 6, the stator core 21 includes a cylindrical portion 23 that forms the outer periphery thereof, and a plurality (60 in this embodiment) of teeth 24 that extend radially inward from the cylindrical portion 23. Consists of. Each tooth 24 is formed with a radially extending portion 24a having a tapered shape whose width in the circumferential direction becomes narrower toward the inner side in the radial direction, and the distal end portion (the radially inner end portion) of each radially extending portion 24a. A wide portion 24b having a wider width in the circumferential direction than the radially extending portion 24a is formed. Both end surfaces in the circumferential direction of the radially extending portion 24a have a planar shape parallel to the axis of the rotary shaft 18, and circumferential end surfaces adjacent to each other in the circumferential direction are parallel to each other.

  A space between the teeth 24 is configured as a slot S that is a part that accommodates the segment conductor 25 that constitutes the armature winding 22. That is, the slot S is configured by the circumferential side surface of the tooth 24 and the inner circumferential surface of the cylindrical portion 23 between the teeth 24. In the present embodiment, the teeth 24 are formed so that the circumferential end surfaces of the radially extending portions 24a adjacent to each other in the circumferential direction are parallel to each other, so that each slot S has a substantially rectangular shape when viewed in the axial direction. It is configured. Each slot S has a shape that penetrates the stator core 21 along the axial direction and opens radially inward. The number of slots S formed in the stator core 21 is the same as that of the teeth 24 (60 in this embodiment).

[Stator core]
The stator core 21 having the above shape is formed by stacking and integrating a plurality of steel plates.

  More specifically, as shown in FIG. 4, the stator core 21 is a main core portion formed by laminating a plurality of core sheets 30 formed by stamping a steel plate by press working and then caulking them together to integrate them. 31 and a magnetic plate 40 (auxiliary core portion) fixed to both ends of the main core portion 31 in the axial direction. In the present embodiment, one magnetic plate 40 having the same shape is provided on each side of the main core portion 31 in the axial direction.

  Each core sheet 30 of the main core portion 31 has the same shape and is disposed so that the plate surface is orthogonal to the axial direction. Each core sheet 30 has an annular portion 32 having an annular shape and a plurality of teeth constituting portions 33 extending radially inward from the annular portion 32. Moreover, each core sheet 30 is laminated | stacked so that the teeth structure part 33 may overlap along an axial direction.

As shown in FIGS. 2, 4, and 6, the magnetic plate 40 is formed by pressing, and a plate-like laminated portion 41 laminated on the core sheet 30 at both axial ends of the main core portion 31. have. The laminated portion 41 is laminated so as to be parallel and coaxial with the core sheet 30 of the main core portion 31. Further, the magnetic plate 40 is set such that the plate thickness T1 is thicker than the plate thickness T2 of the core sheet 30 of the main core portion 31 (see FIG. 1).

  The laminated portion 41 is formed with an annular portion 42 that forms an annular shape that overlaps the annular portion 32 of the core sheet 30 in the axial direction, and a plurality of teeth constituent portions 43 that extend radially inward from the annular portion 42. The teeth constituting portion 43 of the laminated portion 41 has the same shape as the teeth constituting portion 33 of the core sheet 30 in the axial direction view. The magnetic plate 40 is provided such that the annular portion 42 and the tooth constituent portion 43 of the laminated portion 41 overlap the annular portion 32 and the tooth constituent portion 33 of the core sheet 30 in the axial direction. The annular portions 32 and 42 of the core sheet 30 and the magnetic plate 40 constitute a cylindrical portion 23 of the stator core 21, and the tooth constituent portions 33 and 43 constitute a tooth 24 of the stator core 21. Moreover, the outer diameter of the annular part 42 of the laminated part 41 is formed smaller than the outer diameter of the annular part 32 of the core sheet 30 (see FIG. 2). Thereby, it is comprised so that the whole outer periphery of the annular part 32 of the core sheet 30 may be exposed in an axial view.

  A rotor facing portion 44 as a rotor facing portion extending outward in the axial direction (on the side opposite to the main core portion) is formed at the radially inner end (rotor 14 side end) of the teeth constituting portion 43 of the magnetic plate 40. Has been. The rotor facing portion 44 is formed by bending the radially inner end portion of the tooth constituting portion 43 at a right angle outward in the axial direction. That is, the magnetic plate 40 is formed such that the plate surface faces the radial direction by the rotor facing portion 44 that is bent outward in the axial direction. Note that the inner diameter surface of the rotor facing portion 44 is curved so as to have the same diameter as the inner diameter of the main core portion 31 (core sheet 30). Further, the axial thickness of the laminated portion 41 and the radial thickness of the rotor facing portion 44 are determined by the plate thickness T1 of the magnetic plate 40, which are equal to each other. Further, the thickness of the bent portion between the rotor facing portion 44 and the tooth constituting portion 43 (the corner portion formed by the tooth constituting portion 43 and the rotor facing portion 44) is the plate thickness (that is, the magnetic plate) of the rotor facing portion 44. It is formed to be thicker than the plate thickness T1) of 40.

  As shown in FIGS. 3A and 3B, the rotor facing portion 44 has side edge portions 44a and 44b as circumferential side portions on both sides in the circumferential direction. The side edge portions 44a and 44b are shaped to be inclined with respect to the direction of the axis L1 (axial direction) of the rotating shaft 18. The side edge portions 44a and 44b are inclined so as to approach the circumferential center side of the rotor facing portion 44 toward the outer side in the axial direction (on the side opposite to the laminated portion 41). The side edge 44a on the one circumferential side and the side edge 44b on the other circumferential side are symmetric with respect to an imaginary line L2 (straight line along the axis L1) passing through the center in the circumferential direction of the rotor facing portion 44. It is formed to have a shape. For this reason, the rotor facing portion 44 is formed such that the circumferential width on the axial base end side (axially inner side) is equal to the circumferential width of the distal end portions of the teeth constituting portions 33 and 43 constituting the wide portion 24 b of the tooth 24. In addition, the circumferential width is narrower toward the tip end side in the axial direction (outside in the axial direction), and the trapezoidal shape is formed in a radial view. In addition, each rotor opposing part 44 of this embodiment is formed so that all may make the same shape.

  As shown in FIG. 5, convex portions 45 (dowels) projecting in the plate thickness direction are formed by pressing in the annular portions 32 and 42 of the core sheet 30 and the laminated portion 41 of the magnetic plate. In each of the annular portions 32 and 42, a plurality of convex portions 45 (four in the present embodiment) are formed in the circumferential direction. Each annular portion 32, 42 has a concave portion 46 formed at the time of forming the convex portion 45 on the back side of each convex portion 45. Each convex portion 45 is press-fitted and fixed (caulked and fixed) to the concave portion 46 of the core sheet 30 adjacent in the axial direction. Thereby, the core sheets 30 are integrated to form the main core portion 31, and the magnetic plates 40 are fixed to both sides in the axial direction of the main core portion 31.

As shown in FIG. 6, in each slot S of the stator core 21, a sheet-like insulating member 47 made of an insulating resin material is mounted. Each insulating member 47 is provided in a state of being folded back at the radially outer end of the slot S, and is formed along the inner peripheral surface of the slot S. Each insulating member 47 is inserted into the slot S in the axial direction, and the axial length of the insulating member 47 is set longer than the axial length of the slot S. That is, both end portions in the axial direction of the insulating member 47 protrude outward from both end portions in the axial direction of the slot S (see FIG. 7).

[Armature winding]
As shown in FIGS. 6 and 8, the armature winding 22 mounted on the stator core 21 is composed of a plurality of segment conductors 25 (segment conductors). The segment conductors 25 are connected with predetermined ones to form a three-phase (U-phase, V-phase, W-phase) Y-connected armature winding 22. Each segment conductor 25 is formed from a wire having the same cross-sectional shape (rectangular cross-section).

  Each segment conductor 25 includes a pair of straight portions 51 that are portions inserted into the slot S, a first protruding portion 52 that protrudes from the slot S in one axial direction (rear frame 11 side), and a shaft that extends from the slot S. It has the 2nd protrusion part 53 which protrudes to a direction other side (front frame 12 side), and has comprised the substantially U shape folded by the 1st protrusion part 52 side. Further, the first and second projecting portions 52 and 53 are opposed to the rotor facing portion 44 of the magnetic plate 40 in the radial direction.

  The pair of linear portions 51 are formed so that their radial positions are shifted from each other, and are inserted into slots S having different circumferential positions. The straight portion 51 is disposed inside the insulating member 47 in the slot S (see FIG. 6). The segment conductor 25 and the stator core 21 are electrically insulated by the insulating member 47.

  The segment conductors 25 are arranged so that four straight portions 51 are arranged in the radial direction in each slot S. In the segment conductor 25, two linear portions 51 are arranged at the first and fourth from the inner side in the radial direction (the segment conductor 25x illustrated on the outer side in FIG. 8), and the two linear portions 51. Are used, which are arranged second and third from the inside in the radial direction (segment conductor 25y shown inside in FIG. 8). The armature winding 22 is mainly composed of the two types of segment conductors 25x and 25y. For example, the segments constituting the end of the armature winding 22 (power supply connection terminal, neutral point connection terminal, etc.) Another type of conductor (for example, a segment conductor having only one straight portion) is used.

  Each straight portion 51 has a second protrusion 53 that protrudes toward the front frame 12 through the slot S in the axial direction, and is bent in the circumferential direction so that the straight portion 51 of the other segment conductor 25 or a special kind of The segment conductors are electrically connected by welding or the like, whereby the segment conductors 25 constitute the armature windings 22.

Further, the first and second projecting portions 52 and 53 of the segment conductor 25 are bent in the circumferential direction with respect to the linear portion 51 at both axial ends of the slot S. Here, FIG. 7 shows an enlarged view of the vicinity of the end portion in the axial direction of the slot S where the first protrusion 52 is bent in the circumferential direction. As shown in the drawing, a chamfered portion 43a that is chamfered in an arc shape is formed at a corner portion of the teeth constituting portion 43 of the magnetic plate 40 (laminated portion 41) constituting one end of the slot S in the axial direction. Similarly, the chamfered portion 43 a is formed at the corner of the tooth constituting portion 43 that constitutes the other axial end of the slot S in the magnetic plate 40 on the second projecting portion 53 side. The chamfered portion 43a has an arc shape along the circumferentially bent shape of the first and second projecting portions 52 and 53, and comes into contact with the bent portion over a wide area. Thereby, it is suppressed that force is locally applied from the corner portion of the tooth constituent portion 43 to the bent portions in the circumferential direction of the first and second projecting portions 52 and 53, and damage to the bent portions is suppressed. It has become so. Similarly, damage to the insulating member 47 sandwiched between the bent portions of the first and second projecting portions 52 and 53 and the chamfered portion 43a is also suppressed. In this embodiment, since the plate thickness T1 of the magnetic plate 40 (plate thickness of the teeth constituting portion 43) is thicker than the plate thickness T2 of the core sheet 30, the curvature radius Rm of the chamfered portion 43a is set to the plate thickness of the core sheet 30. It can be set larger than T2. Thereby, damage to the bent part of the segment conductor 25 is more suitably suppressed by the chamfered portion 43a having a large curvature radius Rm.

  Further, as shown in FIG. 8, the first protrusion 52 in which the folded portion 25a of the segment conductor 25 is formed is formed so as to incline (expand) radially outward. Thus, the folded portion 25a is biased radially outward from the radial center of the slot S, and the radial inner end 52a of the first protrusion 52 is radially outer than the radial inner end Sa of the slot S. It is comprised so that it may be located in. Thereby, since the gap between the radial direction of the 1st protrusion part 52 and the rotor opposing part 44 of the magnetic board 40 is comprised widely, interference with the 1st protrusion part 52 and the rotor opposing part 44 is suppressed more suitably. ing. As a result, not only the insulation between the segment conductor 25 and the rotor facing portion 44 is more preferably ensured, but also the cogging torque is increased and output due to the deformation of the rotor facing portion 44 due to the interference with the first protrusion 52. The decline of the is suppressed.

  On the other hand, the second projecting portion 53 of the segment conductor 25 is not formed with a folded portion, and the second projecting portions 53 are welded to each other, so that a gap between the second projecting portion 53 and the rotor facing portion 44 is obtained. Can be secured easily. Further, the welded portion of the second projecting portion 53 is formed on the outer side in the axial direction (on the side opposite to the main core portion) of the front end portion of the rotor facing portion 44 on the front frame 12 side. Thereby, in the welding operation of the second projecting portion 53, the rotor facing portion 44 is less likely to become an obstacle, and workability is improved, and insulation between the second projecting portion 53 and the rotor facing portion 44 is more reliably ensured. It is possible. The welding portion of the second protrusion 53 may be set on the axially inner side (the main core portion 31 side) of the front end portion of the rotor facing portion 44 on the front frame 12 side, in this case, Since the 2nd protrusion part 53 can be comprised so that it may not protrude outside an axial direction rather than the rotor opposing part 44, it can contribute to size reduction of the stator 13 in the axial direction.

[Stator core retention structure]
As shown in FIG. 1, the stator holding portions 11 b and 12 b of the frames 11 and 12 holding the stator 13 having the above-described configuration have a cylindrical shape extending in the axial direction from the main body portions 11 a and 12 a of the frames 11 and 12. There is no. The outer diameters of the stator holding portions 11b and 12b are formed larger than the outer diameter of the main core portion 31 of the stator holding portions 11b and 12b. The inner diameters of the stator holding portions 11b and 12b are smaller than the outer diameter of the main core portion 31 and larger than the outer diameter of the magnetic plate 40 (laminated portion 41).

  As shown in FIG. 8, outer fitting portions 11d and 12d are formed at the front end portions (axially inner end portions) of the stator holding portions 11b and 12b, respectively. Each of the outer fitting portions 11d and 12d is a portion where the radial thickness is reduced by increasing the inner diameter of the stator holding portions 11b and 12b, and has an annular shape. The inner diameters of the outer fitting portions 11d and 12d are formed to be substantially equal to the outer diameter of the main core portion 31, and a contact surface having a planar shape perpendicular to the axial direction is formed on the radially inner side of the outer fitting portions 11d and 12d. 11e and 12e are formed.

  In the stator core 21, portions (exposed surfaces 31 a) where the outer peripheral edge of the main core portion 31 is exposed on both sides in the axial direction on the outer peripheral side of the laminated portion 41 of the magnetic plate 40 are formed on the stator holding portions 11 b and 12 b of the frames 11 and 12. It is pinched. Specifically, the stator holding portions 11 b and 12 b have outer fitting portions 11 d and 12 d that are fitted on outer peripheral edges at both axial ends of the main core portion 31, and the contact surfaces 11 e and 12 e are shafts of the main core portion 31. It is in contact with the exposed surfaces 31a on both sides in the axial direction. In this state, the frames 11 and 12 are connected and fixed to each other by the through bolts 15, whereby the main core portion 31 is held in the axial direction by the stator holding portions 11b and 12b. Further, the outer peripheral surface of the main core portion 31 of the stator core 21 is exposed to the outside from between the front end portions of the stator holding portions 11b and 12b.

[Rotor]
As shown in FIGS. 1, 2, and 8, the rotor 14 includes a rotating shaft 18 that is supported by bearings 16, 17, a cylindrical rotor core 61 that is fixed to the rotating shaft 18 so as to be integrally rotatable, and a rotor core. The plurality of (10 in the present embodiment) field magnets 62 are fixed to the outer peripheral surface of 61.

  As shown in FIG. 8, the rotor core 61 is configured by laminating a plurality of first and second core sheets 61a and 61b in the axial direction. The 1st core sheet 61a is provided with the annular | circular shaped annular part 61c as shown in FIG. The second core sheet 61b has a plurality of protrusions 61d in the circumferential direction projecting radially outward on the radially outer surface of the annular portion 61c having substantially the same shape as the first core sheet 61a.

  As shown in FIG. 8, the rotor core 61 of the present embodiment has a plurality of second core sheets 61b each having the protrusion 61d at the substantially center in the axial direction, and a plurality of first core sheets 61a on both sides in the axial direction. It is constructed by stacking. That is, the rotor core 61 is configured such that the protrusion 61d is located on the axially central side.

  As shown in FIG. 2, each field magnet 62 is made of a ferrite magnet, and is arranged such that magnetic poles (N pole and S pole) are alternately different in the circumferential direction. Each field magnet 62 is a so-called segment magnet fixed to the outer peripheral surface of the rotor core with a gap in the circumferential direction.

  The axial lengths of the rotor core 61 and the field magnet 62 of the rotor 14 are the axial lengths of the inner peripheral ends of the stator core 21 (that is, from the tip of the rotor facing portion 44 of one magnetic plate 40 to the other magnetic plate 40). The length of the rotor facing portion 44 is set to be long. That is, the field magnet 62 is opposed to the inner peripheral surface of the main core portion 31 of the stator core 21 and the rotor facing portion 44 of each magnetic plate 40 in the radial direction. Each field magnet 62 is disposed in contact with the protrusion 61d provided substantially at the center side in the axial direction of the rotor core 61 in the circumferential direction or with a slight gap therebetween, thereby suppressing displacement in the circumferential direction (idling). It has been.

  As shown in FIG. 1, the distal end portion (the left end portion in FIG. 1) of the rotating shaft 18 passes through the front frame 12 and protrudes outside the motor 10. A joint 63 that rotates integrally with the rotary shaft 18 is provided at the tip of the rotary shaft 18. The joint 63 is connected to an external device (not shown) and transmits the rotation of the rotary shaft 18 to the external device.

[Relationship between rotor and stator]
Next, the relationship between the rotor 14 and the stator 13 configured as described above will be described.
FIG. 10 shows the relationship between the axial length of the rotor facing portion 44 and the cogging torque, the horizontal axis is the axial length h of the rotor facing portion 44, and the vertical axis is the cogging torque. In FIG. 10, the difference in the axial extension length s of the field magnet 62 with respect to the rotor facing portion 44 is illustrated by changing the line type. Specifically, the axial extension length s of the field magnet 62 with respect to the rotor facing portion 44 is 0.0, 0.25, 0.5, 0.75, 1.0, 1.25, 1.5. There are a total of nine types of 1.75 and 2.0, which are shown in this order by a one-dot chain line, a long broken line, a solid line, a two-dot chain line, a thick one-dot chain line, a thick broken line, a thick solid line, a broken line, and a thick two-dot chain line. Further, FIG. 11 shows a case where the axial extension length s = 0.5 of the field magnet 62 with respect to the rotor facing portion 44 shown by a solid line in FIG. 10 is extracted and shown. In any case, the radial length (plate thickness) t of the rotor facing portion 44 is 1.2 mm, which is the same as the plate thickness T1, as shown in FIG. Further, when the axial length h of the rotor facing portion 44 is increased, the axial length of the field magnet 62 itself is relatively increased.

As can be seen from FIGS. 10 and 11, the change in cogging torque is small in the first range (indicated by R1 in FIG. 11) where the axial length h of the rotor facing portion 44 is relatively low. Then, in the predetermined second range (indicated by R2 in FIG. 11) after the axial length h of the rotor facing portion 44 exceeds the first range R1, which is a relatively low range, the root of the rotor facing portion 44 is obtained. An increase in magnetic flux is induced on the axial base end side, which is a portion, and the cogging torque gradually increases. Further, in the predetermined third range (indicated by R3 in FIG. 11) after the axial length h of the rotor facing portion 44 exceeds the second range R2, the rotor facing portion 44 (magnetic plate 40) The phase of the cogging torque is reversed with respect to the main core portion 31 and becomes a canceling relationship, whereby an increase in the cogging torque is temporarily suppressed. And it turns out that cogging torque deteriorates rapidly in the comparatively long 4th range (it is R4 in Drawing 11) where axial direction length h of rotor facing part 44 exceeded the 3rd range R3.

  12 and 13 show the relationship between the axial length h of the rotor facing portion, the axial extension length s of the field magnet with respect to the rotor facing portion, and the cogging torque. In FIG. 12, the vertical axis is the axial length h of the rotor facing portion 44, the horizontal axis is the axial extension length s of the field magnet 62 with respect to the rotor facing portion 44, and the magnitude of cogging torque in the regions Ar1 to Ar29. It shows. Moreover, in FIG. 13, FIG. 12 is represented in three dimensions. 12 and 13, the regions Ar1, Ar2,..., Ar28, Ar29 are shown in order from the lowest cogging torque. In the cogging torque in the same range, the inside of the region is shown in the same pattern. .

  As can be seen from FIGS. 12 and 13, the longer the axial length h of the rotor facing portion 44, the higher the cogging torque tends to increase, and the axial extension length of the field magnet 62 with respect to the rotor facing portion 44. As s increases, the cogging torque tends to increase. These relationships can be expressed by the following formula 1. In Equation 1, the axial length of the rotor facing portion 44 is h, the radial length (plate thickness) of the rotor facing portion 44 is t, and the axial extension length of the field magnet 62 with respect to the rotor facing portion 44. Is shown as s.

h = t × K−0.5 s (Formula 1)
Here, in this embodiment, by setting the coefficient K in the range of 0 <K <6.3, a cogging torque in a range lower than the straight line X1 in FIG. 12 can be obtained. That is, by configuring the magnetic plate 40 and the field magnet 62 so as to satisfy the above formula 1 with the coefficient K in the range of 0 <K <6.3, a sudden cogging torque can be obtained while considering the amount of magnetic capture. It becomes possible to make the range in which the change is small (the first range R1, the second range R2, and the third range R3 in FIG. 11).

  Furthermore, by setting the lower limit of the coefficient K to be larger than 5.4 and the range of the coefficient K to be 5.4 <K <6.3, the range of the straight line X2 and the straight line X1 in FIG. 12 (the third range). (Range corresponding to R3). That is, by configuring the magnetic plate 40 and the field magnet 62 so that the coefficient K is in the range of 5.4 <K <6.3 and satisfying the above formula 1, the range in which the sudden change in the cogging torque is small (the first step). 3 range R3), it is possible to suitably increase the amount of magnetic capture.

  For this reason, in the motor 10 of this embodiment, it is set as the structure which satisfy | fills said Formula 1 in the range whose said coefficient K is 0 <K <6.3. More preferably, the coefficient K is configured to satisfy Formula 1 in the range of 5.4 <K <6.3.

Next, the operation of this embodiment will be described.
In the motor 10 configured as described above, the magnetic field generated by energization of the armature winding 22 of the stator 13 and the magnetic field of the field magnet 62 of the rotor 14 cause the inner peripheral surface of the main core portion 31 and each magnetic field. The rotor 14 rotates by acting via the rotor facing portion 44 of the plate 40. In the present embodiment, since the thickness T1 of the magnetic plate 40 is set to be thicker than the thickness T2 of the core sheet 30, magnetic saturation is unlikely to occur in the magnetic plate 40, and magnetism is generated via the magnetic plate 40. Easy to import.

  Here, in the motor 10 of the present embodiment, the coefficient K is configured to satisfy the formula 1 in the range of 0 <K <6.3, and therefore the magnetic plate 40 is within a range in which a sudden increase in cogging torque is suppressed. The rotor facing portion 44 is provided to secure the amount of magnetic capture. Furthermore, by setting the coefficient K to satisfy the above formula 1 in the range of 5.4 <K <6.3, in the range where the rapid change in the cogging torque is small (the third range R3), It is possible to suitably increase the amount of uptake.

Further, since the rotor facing portion 44 has a trapezoidal shape when viewed in the radial direction, the rotor facing portion 44 has a shape that is magnetically skewed in the circumferential direction. Thereby, the cogging torque is reduced.
Further, the rotor facing portion 44 of each magnetic plate 40 is formed so as to extend in the axial direction from the rotor 14 side end portion (radially inner end portion) of the teeth 24 of the stator core 21. As a result, the stacking thickness of the main core portion 31 can be suppressed while ensuring the axial length of the surface facing the rotor 14 of the stator core 21 (inner peripheral surface of the stator core 21) to achieve high output. ing. And since the fluctuation | variation (tolerance) of the thickness of the main core part 31 is restrained few by suppressing the thickness of the main core part 31, the space | interval of the axial direction of each flame | frame 11 and 12 which sandwiches the main core part 31 is suppressed. Thus, fluctuations in the axial dimension of the entire motor 10 are suppressed.

  Further, the variation (tolerance) of the magnetic plate 40 increases as the plate thickness T1 increases. However, as in the present embodiment, each of the frames 11 and 12 sandwiches only the main core portion 31 to form the magnetic plate 40. Is configured so as not to abut in the axial direction, so that fluctuations in the axial dimension of the entire motor 10 can be further suppressed.

  In addition, the rotor core 61 of the rotor 14 is configured such that a field magnet 62 fixed on the outer peripheral surface thereof is in contact with the protruding portion 61d of the rotor core 61 in the circumferential direction or with a slight gap. For this reason, the position shift of the circumferential direction of the field magnet 62 is suppressed. Since the protrusion 61d is provided at the axial center of the rotor core 61 so as not to face the magnetic plate 40 in the radial direction, the portions that are easily demagnetized are dispersed in the axial direction. It becomes possible to increase magnetism.

  Further, in the configuration in which the segment conductor 25 is used for the armature winding 22, the number of slots S (the number of teeth 24) that accommodate the segment conductor 25 is large, and the circumferential width of the teeth 24 tends to be narrowed. For this reason, in order to increase the area of the surface (radial inner end surface) facing the rotor 14 in the teeth 24 to improve the output, the rotor facing portion 44 is used to increase the output in the radial direction of the teeth 24 as in the present embodiment. A configuration in which the end face extends in the axial direction is suitable. Further, the tooth 24 of the present embodiment has a configuration in which the magnetic concentration is easily concentrated at the boundary portion between the radially extending portion 24a and the wide portion 24b in which the circumferential width becomes narrower toward the inner peripheral side. Since the stacked portions 41 overlap, the magnetic concentration is relaxed.

Next, the effect of this embodiment will be described.
(1) The axial length of the rotor facing portion 44 is h, the radial length (plate thickness) of the rotor facing portion 44 is t, and the axial extension length of the field magnet 62 with respect to the rotor facing portion 44 is s. By configuring the motor 10 so as to satisfy h = t × K−0.5 s (where the coefficient K is in the range of 0 <K <6.3), cogging in the range of the straight line X1 or less in FIG. Torque is obtained. For this reason, it is possible to provide the rotor facing portion 44 within a range in which the increase in cogging torque is suppressed, and to secure the amount of magnetic capture. Further, by configuring the motor 10 so that the range of the coefficient K satisfies 5.4 <K <6.3, the cogging torque in the range of the straight lines X2 to X1 in FIG. Thus, it is possible to secure a long amount of magnetic force by ensuring a long axial length of the rotor facing portion 44 and a long axial extension length of the field magnet 62.

  (2) Since the teeth constituting portion 33 of the main core portion 31 extending toward the rotor side in the radial direction is configured such that the circumferential width becomes narrower toward the rotor side, the inner rotor type motor as in this embodiment has a diameter. A space for the armature winding 22 can be secured on the inner side in the direction. Further, in this case, since the tooth constituent portion 33 is in contact with the magnetic plate 40, the magnetic saturation concentrated on the narrow portion on the rotor side of the tooth constituent portion 33 can be relaxed to suppress magnetic saturation.

(4) Since the field magnet 62 of the rotor 14 is made of a relatively inexpensive ferrite magnet, it can contribute to cost reduction of the motor.
(5) Since the magnetic plates 40 having the rotor facing portions 44 are formed on both sides in the axial direction, it is possible to further increase the amount of magnetism captured while suppressing the axial length of the main core portion 31. Further, since the armature winding 22 can be disposed on the side opposite to the rotor of the rotor facing portion 44, the axial length can be suppressed.

  (6) The armature winding 22 is inserted into the plurality of slots S formed in the stator core 21 along the axial direction and includes first and second projecting portions 52 and 53 projecting from the slot S in the axial direction. It comprises a plurality of segment conductors 25. The first and second projecting portions 52 and 53 of the segment conductor 25 are configured to face the rotor facing portion 44 of the magnetic plate 40 in the radial direction. As a result, the surface of the stator core 21 facing the rotor 14 can be secured by the rotor facing portion 44 of the magnetic plate 40 to achieve high output, and the size of the stator 13 in the axial direction can be suppressed.

  (7) The stator holding portions 11b and 12b of the frames 11 and 12 are configured so as to directly sandwich the outer peripheral edge (exposed surface 31a) of the main core portion 31 in the axial direction. It is comprised so that it may not contact | abut. For this reason, the fluctuation | variation (tolerance) of the axial direction of each flame | frame 11 and 12 which pinches | interposes the main core part 31 can be suppressed, As a result, it becomes possible to suppress the fluctuation | variation of the axial direction dimension of the motor 10 whole. In addition, in the case of a stator in which the armature winding is composed of segment conductors, the space factor of the armature winding can be configured high, but it can easily generate heat, but the outer peripheral surface of the stator core extends from between each frame to the outside. Since it is exposed, it is preferable that the heat generated in the stator is easily released to the outside.

  (8) Since the plate thickness T1 of the magnetic plate 40 is set to be thicker than the plate thickness T2 of the core sheet 30, it is possible to easily take in magnetism through the magnetic plate 40, and as a result, a higher output is achieved. Can contribute to Further, as in this embodiment, when the plate thickness T1 of the magnetic plate 40 is made thicker than the plate thickness T2 of the core sheet 30 to improve the output, the plate thickness variation of the magnetic plate 40 becomes large. For this reason, by configuring each of the frames 11 and 12 so as not to contact the magnetic plate 40 in the axial direction, the effect of suppressing fluctuations in the axial dimension of the entire motor 10 becomes more remarkable.

In addition, you may change the said embodiment as follows.
In the above embodiment, one magnetic plate 40 is used for each axial end of the main core portion 31, but this is not a limitation. For example, as shown in FIG. 14, two magnetic plates are laminated on the axial end portion of the main core portion 31, or three magnetic plates are used at the axial end portion of the main core portion 31 as shown in FIG. You may use it, laminating | stacking. As shown in FIG. 14, the radial length t2 of the rotor facing portions 71a and 72a of the first and second magnetic plates 71 and 72 is set to be the radial length t2 of the rotor facing portion 71a of the one magnetic plate 71 and the other. And the radial length t2 of the rotor facing portion 72a of the magnetic plate correspond to the radial length t of the rotor facing portion 44 of the above embodiment. Further, as shown in FIG. 15, the radial length t3 of the rotor facing portions 75a, 76a, 77a of the first to third magnetic plates 75, 76, 77 is set, and the first to third magnetic plates 75, 76, 77 are used. The radial length t3 of the rotor facing portions 75a, 76a, and 77a is added to correspond to the radial length t of the rotor facing portion 44 of the above embodiment.

  In the above embodiment, the stator holding portions 11 b and 12 b of the frames 11 and 12 directly sandwich the outer peripheral edge (exposed surface 31 a) of the main core portion 31 in the axial direction, and the axial direction with respect to the magnetic plate 40. However, the present invention is not particularly limited to this. For example, as shown in FIG. 16, the main core portion 31 may be sandwiched in the axial direction via the annular portion 42 (laminated portion 41) of the magnetic plate 40. According to the configuration shown in FIG. 16, it is not necessary to reduce the laminated portion 41 of the magnetic plate 40 in the radial direction so as not to interfere with the stator holding portions 11 b and 12 b in the axial direction. Can be suppressed. Further, when the plate thickness T1 of the magnetic plate 40 is made thicker than the plate thickness T2 of the core sheet 30 to improve the output, by adjusting the number of the core sheets 30 that are thinner than the magnetic plate 40, It is possible to suppress variations in the axial dimension of the entire motor 10.

  In the above embodiment, each segment conductor 25 is formed so as to be folded back on the first projecting portion 52 side connecting the pair of linear portions 51 inserted through the slot S, and joined by welding or the like on the second projecting portion 53 side. However, the present invention is not particularly limited to this. For example, as shown in FIG. 17, the pair of linear portions 51 may be separated from each other, and the first projecting portion 52 may be joined by welding or the like. Further, the connection between the segment conductors 25 may be a connection structure using another member such as a bus bar in addition to welding.

  In the above embodiment, the exposed surface 31 a is formed over the entire outer peripheral edge of the axial end surface of the main core portion 31 by making the outer diameter of the laminated portion 41 of the magnetic plate 40 smaller than the outer diameter of the core sheet 30. In addition, the exposed surface 31a is configured to be sandwiched between the stator holding portions 11b and 12b of the frames 11 and 12, but is not particularly limited thereto. For example, a protruding portion that protrudes radially outward from the outer peripheral surface of the main core portion 31 (core sheet 30) may be formed, and the protruding portion may be sandwiched between the stator holding portions 11b and 12b.

  In the above embodiment, the laminated portion 41 of the magnetic plate 40 includes the annular portion 42 and the tooth constituent portion 43. However, for example, the laminated portion 41 may be constituted by only the tooth constituent portion 43.

In the above embodiment, the magnetic plate 40 is caulked and fixed to the main core portion 31 (core sheet 30), but other than this, for example, it may be fixed by adhesion or welding.
In the above embodiment, the plate thickness T1 of the magnetic plate 40 is set to be thicker than the plate thickness T2 of the core sheet 30. However, the present invention is not limited to this. It may be set equal to or thinner than the plate thickness T2.

In the above embodiment, the armature winding 22 configured by the segment conductor 25 is used. However, for example, an armature winding formed by winding a copper wire or the like around a tooth may be used.
In the above embodiment, the ferrite magnet is used as the field magnet 62 of the rotor 14, but other magnets such as a neodymium magnet may be used.

  In the above embodiment, the rotor core 61 has a laminated structure composed of a plurality of first and second core sheets 61a and 61b. However, for example, the rotor core 61 may be an integrally molded product formed by casting or the like. However, even in such a configuration, the protrusion 61d as the positioning portion is formed.

In the above embodiment, the rotor 14 is embodied as the inner rotor type motor 10 arranged on the inner peripheral side of the stator 13, but is not particularly limited to this, and the outer rotor type in which the rotor is arranged on the outer peripheral side of the stator It may be embodied in the motor.

  DESCRIPTION OF SYMBOLS 10 ... Motor, 11 ... Rear frame (first frame), 12 ... Front frame (second frame), 13 ... Stator, 14 ... Rotor, 18 ... Rotating shaft, 21 ... Stator core, 22 ... Armature winding, 25, 25x, 25y ... segment conductors, 30 ... core sheet, 31 ... main core part, 33 ... teeth constituent part, 40 ... magnetic plate, 41 ... laminated part, 43 ... tooth constituent part, 44 ... rotor facing part, 61 ... rotor core, 61a ... core sheet, 62 ... field magnet, 71, 72, 75, 76, 77 ... magnetic plate, 71a, 72a, 75a, 76a, 77a ... rotor facing part, S ... slot, T1, T2 ... plate thickness, h ... axial length, s ... axial extension length, t, t2, t3 ... radial length.

Claims (9)

A stator core having a plurality of core sheets stacked in the axial direction of the rotating shaft, and a stator having an armature winding provided on the stator core;
A rotor having a field magnet radially facing the stator core;
A motor equipped with
The stator core includes a main core portion in which the core sheet having a tooth constituent portion around which the armature winding is wound is laminated in an axial direction, and a magnetic plate provided at an axial end portion of the main core portion; With
The magnetic plate includes a laminated portion laminated at an axial end portion of the main core portion, a rotor extending radially outward from an end portion on the rotor side of the laminated portion and facing the rotor in a radial direction. An axial length of the rotor facing portion, t a radial length (plate thickness) of the rotor facing portion, and an axial extension length of the field magnet with respect to the rotor facing portion. s, it is configured to satisfy h = t × K−0.5s (where the coefficient K is in the range of 5 <K <6.3) ,
An axial extension length s of the field magnet with respect to the rotor facing portion is configured to satisfy a range of 0 <s <2.0, and a radial length t of the rotor facing portion is set with respect to the rotor facing portion. motor characterized that you have been configured to be larger than the axial length of extension s of the field magnet. The motor according to claim 1,
The magnetic plate is configured so that a range of the coefficient K satisfies 5.4 <K <6.3. The motor according to claim 1 or 2,
The tooth component extends in the radial direction toward the rotor, and is formed such that a circumferential width is narrower toward the rotor. The motor according to any one of claims 1 to 3,
2. The motor according to claim 1, wherein the field magnet of the rotor is a ferrite magnet. In the motor according to any one of claims 1 to 4,
The motor according to claim 1, wherein the magnetic plates are provided on both axial sides of the main core portion. In the motor according to any one of claims 1 to 5,
The armature winding is composed of a plurality of segment conductors that are inserted into a plurality of slots formed in the stator core along the axial direction, and projecting portions that protrude in the axial direction from the slots are electrically connected to each other. ,
The motor according to claim 1, wherein the projecting portion of the segment conductor is configured to radially oppose the rotor facing portion of the magnetic plate. In the motor according to any one of claims 1 to 6,
A first frame and a second frame provided on both sides of the stator core in the axial direction and sandwiching the stator core in the axial direction;
The motor according to claim 1, wherein the outer peripheral surface of the stator core is exposed to the outside from between the first frame and the second frame. The motor according to claim 7, wherein
The first and second frames are configured to sandwich the main core portion in the axial direction through the laminated portion of the magnetic plate. The motor according to any one of claims 1 to 8,
The motor is characterized in that the thickness of the magnetic plate is set larger than the thickness of the core sheet.