JP2023000668A - motor - Google Patents

Abstract

To provide a motor that can be lightened in weight.SOLUTION: A motor 10 includes a rotor 12, a plurality of coils 16, and an annularly formed stator core 26. Each coil 16 includes an opposing part 36 and a coil end part 38. The opposing parts 36 of the plurality of coils 16 are arranged along an internal peripheral surface of the stator core 26. The coil end part 38 of the plurality of coils 16 on one side in an axial direction and the coil end part 38 thereof on the other side in the axial direction are arranged along an end surface of the stator core 26 in an axial direction. A lightening hole 26B is formed in a portion on a side opposite to the opposing part 36 in the stator core 26. The shape, dimension, number and arrangement of the lightening hole 26B are set such that the maximum magnetic flux density at the inside of the stator core 26 at a position closest to the opposing part in the lightening hole 26B is less than the saturation magnetic flux density of a material that forms the stator core 26.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to motors.

Patent Literature 1 listed below discloses a motor configured by arranging a plurality of coils along a ring-shaped fixed ring. In the motor described in this document, the A-phase coil and the B-phase coil formed by winding the windings in a rectangular shape and bending both ends in the axial direction in the radial direction are fixed rings. are arranged alternately along the circumferential direction of the Coil end portions, which are axial end portions of the A-phase coil and the B-phase coil, are arranged along both axial end faces of the fixed ring.

JP-A-4-58747

By the way, in the configuration in which the coil end portion of the coil is arranged along the axial end surface of the fixing ring as in the configuration described in Patent Document 1, the radial dimension of the fixing ring is the diameter of the coil end portion. It should be set to the direction dimension and the corresponding dimension. That is, there is a constraint on reducing the radial dimension of the fixing ring. As a result, weight reduction of the motor is hindered.

An object of the present disclosure is to obtain a motor capable of achieving weight reduction in consideration of the above facts.

A motor (10, 54, 56, 64, 66, 68, 84, 86, 90, 94) for solving the above problems includes a rotating body (12) having a magnet (18) and rotatably supported; Each is formed by winding a conductive winding (30) in a ring, and a part of the winding is arranged side by side in the circumferential direction and arranged to face the center of the magnet in the axial direction in the radial direction. and coil end portions (38) forming portions on one side and the other side in the axial direction with respect to the facing portion, respectively, and a plurality of coils arranged annularly in the circumferential direction. The coil (16) is formed in an annular shape, and the facing portions of the plurality of coils are arranged along the inner peripheral surface or the outer peripheral surface, and the coil end portion and the coil end portion on one side in the axial direction of the plurality of coils. At least one of the coil end portions on the other side in the axial direction is arranged along the end surface in the axial direction, and lightening portions (26B, 26C) are formed on the opposite side to the facing portion. and a core (26) , wherein the lightening is performed so that the maximum magnetic flux density inside the core at a position closest to the facing portion in the lightening portion is less than the saturation magnetic flux density of the material forming the core. The shape, size, number and arrangement of parts are set.

By configuring in this way, the weight can be reduced.

FIG. 2 is a partial cross-sectional perspective view showing the rotor and stator of the motor of the first embodiment; FIG. 4 is a side cross-sectional view showing a cross section of the motor cut along the axial direction; 4 is a plan view showing a stator and rotor; FIG. 3 is a cross-sectional view showing a stator and rotor; FIG. It is a perspective view showing a stator. It is a perspective view which shows a short coil. It is a perspective view which shows a long coil. FIG. 4 is an enlarged plan view showing an enlarged boundary between a facing portion and a coil end portion; FIG. 4 is an enlarged side cross-sectional view showing an enlarged boundary between a facing portion and a coil end portion; It is a schematic diagram for demonstrating the connection of U-phase, V-phase, and W-phase. FIG. 4 is a schematic diagram for explaining connections and arrangements of U-phase, V-phase, and W-phase; FIG. 4 is a side cross-sectional view showing a cross section of a portion of the stator cut along the axial direction; 3 is a perspective view showing insulators and coils supported by a rotor core via the insulators; FIG. FIG. 14 is a perspective view showing an insulator and a coil supported by the rotor core via the insulator, showing an example in which an insulator different from that in FIG. 13 is applied; 3 is a perspective view showing an insulator and a U-phase coil, a V-phase coil, and a W-phase coil supported by a rotor core via the insulator; FIG. FIG. 7 is a cross-sectional view showing the stator and rotor of the motor of the second embodiment; FIG. 11 is a perspective view schematically showing a stator core of a motor according to a third embodiment; FIG. 11 is a sectional view showing the stator and rotor of the motor of the fourth embodiment; FIG. 11 is a perspective view showing a stator core of a motor according to a fifth embodiment; FIG. 11 is a side cross-sectional view showing a stator of a motor according to a fifth embodiment; FIG. 11 is a plan view showing a stator core of a motor according to a sixth embodiment; FIG. 11 is a plan view showing a stator core of a motor of a seventh embodiment; FIG. 21 is a perspective view showing a stator core of a motor of an eighth embodiment; FIG. 21 is a schematic diagram schematically showing the structure of the stator core of the motor of the eighth embodiment; FIG. 21 is a perspective view showing a stator core of a motor of a ninth embodiment; FIG. 21 is a perspective view showing a stator core of a motor according to a tenth embodiment; FIG. 22 is a perspective view showing a stator core of the motor of the eleventh embodiment; FIG. 22 is a cross-sectional view showing part of the stator core of the motor of the twelfth embodiment; FIG. 22 is a cross-sectional view showing part of the stator core of the motor of the thirteenth embodiment; FIG. 21 is a cross-sectional view showing part of a stator core of a motor according to a fourteenth embodiment; FIG. 22 is a cross-sectional view showing part of the stator core of the motor of the fifteenth embodiment; FIG. 22 is a cross-sectional view showing part of the stator core of the motor of the sixteenth embodiment; FIG. 22 is a cross-sectional view showing part of the stator core of the motor of the seventeenth embodiment; FIG. 22 is a cross-sectional view showing part of the stator core of the motor of the eighteenth embodiment; FIG. 20 is a side cross-sectional view showing the stator of the motor of the nineteenth embodiment; FIG. 20 is a perspective view showing an insulator of a motor according to a twentieth embodiment; FIG. 11 is a perspective view showing a U-phase coil, a V-phase coil, and a W-phase coil supported by a rotor core via an insulator and an insulator of a motor according to a twentieth embodiment; FIG. 22 is an enlarged plan view showing an enlarged part of the motor of the twenty-first embodiment; FIG. 22 is an enlarged plan view showing an enlarged part of the motor of the twenty-second embodiment; FIG. 22 is an enlarged plan view showing an enlarged part of the motor of the twenty-third embodiment; FIG. 22 is an enlarged plan view showing an enlarged part of the motor of the twenty-fourth embodiment; FIG. 22 is an enlarged plan view showing an enlarged part of the motor of the twenty-fifth embodiment; FIG. 14 is a schematic diagram showing the rotor and stator of the motor of the twenty-sixth embodiment; FIG. 21 is a schematic diagram showing the rotor and stator of the motor of the twenty-seventh embodiment; FIG. 5 is a side cross-sectional view for explaining variations in bending of coil end portions; FIG. 5 is a side cross-sectional view for explaining variations in bending of coil end portions; FIG. 5 is a side cross-sectional view for explaining variations in bending of coil end portions; FIG. 5 is a side cross-sectional view for explaining variations in bending of coil end portions; FIG. 4 is a diagram for explaining the positional relationship between coil end portions and magnets; FIG. 5 is an enlarged perspective view for explaining variations of terminal portions of windings forming a coil; FIG. 5 is an enlarged perspective view for explaining variations of terminal portions of windings forming a coil; FIG. 5 is an enlarged perspective view for explaining variations of terminal portions of windings forming a coil;

(First embodiment)
A motor 10 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 15. FIG. First, the overall configuration of the motor will be described, and then the configuration of the main part of the present embodiment will be described. The arrow Z direction, arrow R direction, and arrow C direction appropriately shown in the drawings indicate one side in the rotation axis direction, the outer side in the rotation radial direction, and the one side in the rotation circumferential direction of the rotor 12, which will be described later. Further, hereinafter, when simply indicating an axial direction, a radial direction, and a circumferential direction, unless otherwise specified, it indicates a rotating shaft direction, a rotating radial direction, and a rotating circumferential direction of the rotor 12 .

As shown in FIGS. 1 to 3, the motor 10 of this embodiment is an inner rotor type brushless motor in which a rotor 12 as a rotating body is arranged radially inside a stator 14 . 1 to 5 are diagrams of the motor 10 and the like shown as an example, and the number of coils 16 and the number of magnets 18 are not the same as those described later.

The rotor 12 includes a rotating shaft 22 rotatably supported via a pair of bearings 20, a rotor core 24 formed in a free-bottom cylindrical shape and fixed to the rotating shaft 22, and a radially outer surface of the rotor core 24. and a plurality of magnets 18 fixed to.

The rotor core 24 includes a first cylindrical portion 24A to which the rotary shaft 22 is fixed by press fitting or the like, and a second cylindrical portion 24A disposed radially outside the first cylindrical portion 24A. A cylindrical portion 24B, and a disc-shaped connection plate portion 24C that radially connects the end portion of the first cylindrical portion 24A on one axial side and the end portion of the second cylindrical portion 24B on one axial direction side. ing. The outer peripheral surface, which is the radially outer surface of the second cylindrical portion 24B, is formed in the shape of a cylindrical surface along the circumferential direction. A magnet 18, which will be described later, is fixed to the outer peripheral surface of the second cylindrical portion 24B.

The plurality of magnets 18 are formed using a magnetic compound having an intrinsic coercive force Hc of 400 [kA/m] or more and a residual magnetic flux density Br of 1.0 [T] or more. As an example, the magnet 18 of this embodiment is formed using a magnetic compound such as NdFe ₁₁ TiN, Nd ₂ Fe ₁₄ B, Sm ₂ Fe ₁₇ N ₃ , FeNi. Also, a plurality of magnets 18 are fixed to the outer peripheral surface of the second cylindrical portion 24B of the rotor core 24 . The magnets 18 having N poles on the radially outer surfaces and the magnets 18 having S poles on the radially outer surfaces are alternately arranged in the circumferential direction. The number of magnets 18 may be appropriately set in consideration of the output required of the motor 10 and the like.

As shown in FIG. 5, the stator 14 includes a stator core 26 as an annular core, an insulator 28 attached to the stator core 26 by adhesion, fitting, or the like, and an insulator 28 attached to the stator core 26 . a plurality of coils 16; The stator 14 of this embodiment has a toothless structure in which a part of the stator core 26 is not arranged inside the coil 16 .

As shown in FIGS. 1 and 5, the stator core 26 is formed annularly using a magnetic material such as steel. A cross section obtained by cutting the stator core 26 along the axial direction and the radial direction is a rectangular cross section whose longitudinal direction is the axial direction. The stator core 26 is arranged coaxially with the rotor 12, and the axial center position of the stator core 26 and the axial center positions of the plurality of magnets 18 fixed to the rotor core 24 are aligned in the axial direction. . Further, as shown in FIG. 2, the stator core 26 is supported by a housing 74 as a core supporting member forming the outer shell of the motor 10. As shown in FIG. Here, the stator core 26 is arranged inside a housing 74 formed in a cylindrical shape with a bottom. The stator core 26 is supported by the housing 74 by, for example, press-fitting the stator core 26 into the housing 74 . The stator 14 is thereby supported by the housing 74 . A stepped portion 74A is formed on one side in the axial direction of the portion of the housing 74 into which the stator core 26 is press-fitted.

As shown in FIGS. 1 and 5, the insulator 28 is made of a highly insulating material such as a resin material. The insulator 28 covers the radial inner surface and both axial end surfaces of the stator core 26 when the insulator 28 is attached to the stator core 26 . A specific configuration of the insulator 28 will be detailed later.

As shown in FIGS. 5 to 7, the plurality of coils 16 are formed by winding conductive windings (conductors) in an annular shape. Here, as shown in FIGS. 6 and 7, the windings 30 forming the coil 16 of the present embodiment are viewed in a cross section cut along the longitudinal direction in the first direction ( It has a rectangular cross section in which the dimension L1 in the direction of arrow A1) is set larger than the dimension L2 in the second direction (arrow A2) perpendicular to the first direction. Alternatively, the winding 30 may be a wire assembly formed by bundling conductive wires. Moreover, the resistance value between the bundled strands is larger than the resistance value of the strands themselves. The cross-sectional shape of the wire 30 may be oval or elliptical. Also, an enameled wire is generally suitably used for the winding 30, and copper, aluminum, or the like is used as a conductive member.

As shown in FIGS. 5 to 7, the stator 14 of this embodiment includes two types of coils 16 having different axial dimensions. Here, the coil 16 shown in FIG. 6 is called a short coil 32. As shown in FIG. Also, the coil 16 shown in FIG. 7 is called a long coil 34 . Note that the number of coils 16 may be appropriately set in consideration of the output required of the motor 10 and the like.

As shown in FIG. 6, the short coil 32 is wound in a rectangular shape so that the windings 30 are stacked in the second direction (arrow A2 direction), and then both ends in the axial direction are radially outward. It is formed by bending toward. As a result, the short coil 32 has a pair of opposing portions 36 in which a portion of the winding 30 is arranged side by side in the circumferential direction and is spaced apart in the circumferential direction. One coil end portion 38 that circumferentially connects the end portions on the side and the other coil end portion 38 that circumferentially connects the ends of the pair of opposing portions 36 on the other side in the axial direction. . A terminal portion 40 on one side of the winding 30 forming the short coil 32 extends from one side in the circumferential direction of the opposite portion 36 on the one side in the circumferential direction to the one side in the axial direction. A terminal portion 40 on the other side of the winding 30 forming the short coil 32 extends from the one side in the circumferential direction of the opposing portion 36 on the other side in the circumferential direction to the one side in the axial direction. With the terminal portions 40 arranged in this way, in the short coil 32 of the present embodiment, the number of layers of the windings 30 in the coil end portion 38 on one side in the axial direction is reduced to that of the coil end portion 38 on the other side in the axial direction. The number of laminations is smaller than the number of laminations of the windings 30 in . More specifically, the coil end portion 38 on one side in the axial direction has six windings 30 laminated, and the coil end portion 38 on the other side in the axial direction has seven windings 30 laminated. ing. Note that the number of layers of the windings 30 in the pair of facing portions 36 is seven.

Here, the manufacturing process of the short coil 32 will be briefly described. In the manufacturing process of the short coil 32, first, the winding 30 is wound in a rectangular shape so that the winding 30 is laminated in the second direction (arrow A2 direction). Next, the rectangular wound portions of the short coil 32 excluding the pair of terminal portions 40 are joined using a joining member (not shown). As a result, the portions (laminated windings 30) forming the pair of facing portions 36, the coil end portion 38 on one side in the axial direction, and the coil end portion 38 on the other side in the axial direction in the short coil 32 are arranged in the second direction. inseparably bound to. Next, as shown in FIGS. 8 and 9, the portions forming the coil end portion 38 on one axial side and the coil end portion 38 on the other axial side of the short coil 32 are directed outward in the radial direction at approximately right angles. bend to That is, the boundary between the pair of coil end portions 38 and the pair of facing portions 36 is bent substantially at right angles in the first direction. As a result, the pair of opposing portions 36 are arranged along the radially inner surface of the stator core 26 , and the coil end portions 38 on one axial side and the other axial side are arranged along both axial end surfaces of the stator core 26 . A short coil 32 in the arranged configuration is formed. The short coil 32 is manufactured through the above steps.

As shown in FIGS. 6 and 7, the long coil 34 has an axial dimension H2 that is larger than the axial dimension H1 of the short coil 32. has the same configuration as the short coil 32 . Here, portions of the long coil 34 corresponding to those of the short coil 32 are denoted by the same reference numerals as those of the short coil 32, and description of these portions is omitted. Also, the long coil 34 is manufactured through the same process as the short coil 32 . By the way, the length of the windings 30 forming the long coil 34 is longer than the length of the windings 30 forming the short coil 32 . Thereby, the electric resistance of the long coil 34 is higher than that of the short coil 32 .

As shown in FIG. 10, the plurality of coils 16 are connected by star connection as an example. A U-phase 42U, a V-phase 42V and a W-phase 42W in this example are configured to include two short coils 32 and two long coils 34, respectively. In U-phase 42U, these four coils 16 are connected in series in the order of long coil 34, short coil 32, long coil 34, and short coil 32 from the neutral point 44 side. In the V-phase 42V, these four coils 16 are connected in series in the order of the long coil 34, the short coil 32, the long coil 34, and the short coil 32 from the neutral point 44 side. Furthermore, in the W-phase 42W, these four coils 16 are connected in series in the order of the short coil 32, the long coil 34, the short coil 32, and the long coil 34 from the neutral point 44 side. In addition, each coil 16 is connected using a connection member such as a bus bar.

Here, the range from the short coil 32 farthest from the neutral point 44 to the neutral point 44 in the U-phase 42U is called a U-phase coil connection 46U. The range from the short coil 32 farthest from the neutral point 44 to the neutral point 44 in the V-phase 42V is called a V-phase coil connection 46V. Further, the range from the long coil 34 farthest from the neutral point 44 to the neutral point 44 in the W-phase 42W is called a W-phase coil connection 46W. In the present embodiment, the number of long coils 34 and the number of short coils 32 of each phase coil connection bodies 46U, 46V, and 46W are set to the same number, so that the coil connection bodies 46U of each phase , 46V and 46W are the same as each other. Here, the fact that the combined resistance of the coil connections 46U, 46V, and 46W of each phase is the same combined resistance means that the combined resistance of the coil connections 46U of one phase and the coil connections 46V of the other phase , and the combined resistance of 46 W is within plus or minus 5%.

FIG. 11 shows the arrangement of the coils 16 of the U phase 42U, the coils 16 of the V phase 42V, and the coils 16 of the W phase 42W. As shown in FIGS. 11 and 12 , the short coil 32 furthest from the neutral point 44 in the U-phase 42U and the short coil 32 furthest from the neutral point 44 in the V-phase 42V extend along the stator core 26 in the circumferential direction. are placed next to each other. In addition, the long coil 34 farthest from the neutral point 44 in the W phase 42W straddles the short coil 32 farthest from the neutral point 44 in the U phase 42U and the short coil 32 farthest from the neutral point 44 in the V phase 42V. placed in

The short coil 32 farthest from the neutral point 44 in the V-phase 42V and the short coil 32 on the side opposite to the neutral point 44 in the W-phase 42W are arranged adjacent to each other in the circumferential direction along the stator core 26. . Furthermore, the long coil 34 on the side opposite to the neutral point 44 in the U phase 42U is the short coil 32 farthest from the neutral point 44 in the V phase 42V, and the short coil 32 on the side opposite to the neutral point 44 in the W phase 42W. It is arranged so as to straddle 32.

The short coil 32 on the side opposite to the neutral point 44 in the W phase 42W and the short coil 32 on the side of the neutral point 44 in the U phase 42U are arranged side by side along the stator core 26 in the circumferential direction. Furthermore, the long coil 34 on the side opposite to the neutral point 44 in the V-phase 42V, the short coil 32 on the side opposite to the neutral point 44 in the W-phase 42W, and the short coil 32 on the side of the neutral point 44 in the U-phase 42U placed across the

The short coil 32 on the side of the neutral point 44 in the U-phase 42U and the short coil 32 on the side of the neutral point 44 in the V-phase 42V are arranged adjacent to each other along the stator core 26 in the circumferential direction. Further, the long coil 34 on the side of the neutral point 44 in the W phase 42W is arranged to straddle the short coil 32 on the side of the neutral point 44 in the U phase 42U and the short coil 32 on the side of the neutral point 44 in the V phase 42V. be.

The short coil 32 on the side of the neutral point 44 in the V-phase 42V and the short coil 32 on the side of the neutral point 44 in the W-phase 42W are arranged side by side along the stator core 26 in the circumferential direction. Further, the long coil 34 on the side of the neutral point 44 in the U-phase 42U is arranged so as to straddle the short coil 32 on the side of the neutral point 44 in the V-phase 42V and the short coil 32 on the side of the neutral point 44 in the W-phase 42W. be.

The short coil 32 on the side of the neutral point 44 in the W phase 42W and the short coil 32 farthest from the neutral point 44 in the U phase 42U are arranged adjacent to each other along the stator core 26 in the circumferential direction. Further, the long coil 34 on the side of the neutral point 44 in the V-phase 42V is arranged to straddle the short coil 32 on the side of the neutral point 44 in the W-phase 42W and the short coil 32 farthest from the neutral point 44 in the U-phase 42U. be done.

Here, as shown in FIGS. 12 and 13, the insulator 28 to which each coil 16 is attached includes an inner surface covering portion 28A that covers the radially inner surface of the stator core 26, and both axial end surfaces of the stator core 26. A pair of shaft end surface covering portions 28B for covering, and a pair of outer peripheral side flange portions 28C extending axially from the radially outer end portions of the pair of shaft end surface covering portions 28B. The insulator 28 of the present embodiment has a split structure that can be split in the axial direction at the center portion of the inner surface covering portion 28A in the axial direction. The insulator 28 also includes a plurality of circumferential positioning portions 28D for positioning the short coils 32 in the circumferential direction. The plurality of circumferential positioning portions 28D are formed in a convex shape toward the inside in the radial direction from the outer peripheral side flange portion 28C, and are arranged at regular intervals along the circumferential direction. The short coil 32 is positioned in the circumferential direction by disposing the coil end portion 38 of the short coil 32 between a pair of circumferentially adjacent circumferential positioning portions 28D. there is The plurality of circumferential positioning portions 28D may be provided on one outer peripheral flange portion 28C, but may be provided on both outer peripheral flange portions 28C. Also, as shown in FIG. 14, the portion corresponding to the inner surface covering portion 28A may be a sheet-like paper insulator, and the other portion may be an insulator 29 having the same structure as the insulator 28 shown in FIG. In the insulator 29 shown in FIG. 14, portions corresponding to the insulator 28 shown in FIG.

As shown in FIGS. 2 and 4, the insulator 28 includes a convex core engaging portion 28J projecting from a shaft end surface covering portion 28B on one axial side toward the stator core 26 and a core engaging portion 28J on the other axial side. A core engaging portion 28J projecting in a convex shape toward the stator core 26 side from the shaft end surface covering portion 28B is provided. The core engaging portion 28J is engaged with a lightening hole 26B, which will be described later, so that displacement of the insulator 28 with respect to the stator core 26 in the circumferential direction is restricted.

As shown in FIGS. 2 and 5, the insulator 28 protrudes radially outward from the radially outer surface of the outer peripheral flange portion 28C on one axial side. It has an outer flange portion 28K. The radially outer flange portion 28K is formed in an annular shape when viewed from the axial direction. Further, the insulator 28 is provided with a plurality of notch portions 28L as circumferential direction reference portions recessed toward the outer peripheral side flange portion 28C side on one axial side while notching the radially outer flange portion 28K. The plurality of notches 28L are arranged at regular intervals along the circumferential direction. Further, the outer peripheral flange portion 28C on the other axial side is also formed with a plurality of notch portions 28L as circumferential reference portions recessed toward the outer peripheral flange portion 28C on the other axial side. When the stator core 26 is press-fitted into the housing 74, the radially outer flange portion 28K of the insulator 28 contacts the stepped portion 74A of the housing 74, thereby axially positioning the stator core 26 with respect to the housing 74. It's like Further, when the stator core 26 is press-fitted into the housing 74, the notch 28L of the insulator 28 is engaged with a part of the housing 74, thereby positioning the stator core 26 in the circumferential direction with respect to the housing 74. ing.

As shown in FIGS. 11, 12 and 15, the facing portion 36 of the short coil 32 and the facing portion 36 of the long coil 34 are arranged on the radially inner surface of the stator core 26 via the inner surface coating portion 28A of the insulator 28. along and at the same radial position. More specifically, in the state shown in FIG. 15, the facing portion 36 on one side in the circumferential direction of the U-phase short coil 32 and the facing portion 36 on the other side in the circumferential direction of the V-phase short coil 32 are adjacent in the circumferential direction. are arranged adjacent to each other in the circumferential direction, and the facing portion 36 on the one side in the circumferential direction of the short coil 32 of the U phase and the facing portion 36 on the other side in the circumferential direction of the short coil 32 of the V phase that are adjacent in the circumferential direction are , and between a pair of facing portions 36 of the W-phase long coils 34 . As shown in FIGS. 11 and 15, the opposing portions 36 of the other short coils 32 and the opposing portions 36 of the other long coils 34 are arranged along the radially inner surface of the stator core 26 in a similar relationship. . In addition, the axial center position of the opposed portion 36 of the short coil 32 and the axial center position of the opposed portion 36 of the long coil 34 and the axial center position of the magnet 18 are aligned with each other in the axial direction. In the arranged state, the facing portion 36 of the short coil 32 and the facing portion 36 of the long coil 34 and the magnet 18 are arranged to face each other in the radial direction. Also, the first direction of the windings 30 forming the opposing portion 36 of the short coil 32 and the opposing portion 36 of the long coil 34 is directed toward the magnet 18 side.

As shown in FIGS. 11, 12 and 15, the pair of coil end portions 38 of the short coil 32 extend along both axial end surfaces of the stator core 26 via the pair of axial end surface covering portions 28B of the insulator 28. placed respectively. Also, the pair of coil end portions 38 of the long coil 34 are connected to both ends of the stator core 26 in the axial direction via the coil end portions 38 of the two short coils 32 adjacent in the circumferential direction and the pair of axial end surface covering portions 28B of the insulator 28 . placed along each side. That is, the pair of coil end portions 38 of the long coil 34 are arranged to overlap in the axial direction with the pair of coil end portions 38 of the two short coils 32 adjacent in the circumferential direction. More specifically, in the state shown in FIG. 15 , the pair of coil end portions 38 of the W-phase long coil 34 is located on one side of the pair of coil end portions 38 of the U-phase short coil 32 adjacent in the circumferential direction. The side portion and the portion on the other side in the circumferential direction of the pair of coil end portions 38 of the V-phase short coil 32 are arranged to overlap each other in the axial direction. As shown in FIGS. 11 and 15, the coil end portions 38 of the other short coils 32 and the coil end portions 38 of the other long coils 34 are arranged along both axial end surfaces of the stator core 26 in the same relationship. be done.

Next, the configuration of the main part of this embodiment will be described.

FIG. 4 shows a cross section of the stator 14 taken along the radial direction. The radial thickness dimension of the stator core 26 forming part of the stator 14 is set to be larger than the radial dimension of the coil end portions 38 of the coils 16 . In addition, a plurality of lightening holes 26B as lightening portions are formed in a portion of the stator core 26 opposite to the side on which the facing portion 36 of the coil 16 is arranged. That is, a plurality of lightening holes 26B are formed in the outer peripheral portion of the stator core 26. As shown in FIG. The lightening hole 26B is formed so as to penetrate the outer peripheral portion of the stator core 26 in the axial direction. The shape of the lightening hole 26B viewed from the axial direction is circular. Moreover, the plurality of lightening holes 26B are arranged at regular intervals along the circumferential direction.

Here, in the present embodiment, the number of lightening holes 26B is set to an integer multiple of a prime number that is not a prime factor of the number of magnetic poles of the magnets 18 of the rotor 12 . More specifically, in the configuration of the rotor 12 of this embodiment, the number of magnetic poles of the magnets 18 and the number of magnets 18 are the same. Therefore, the number of lightening holes 26B is set to an integer multiple of a prime number that is not a prime factor of the number of magnets 18 of the rotor 12 .

As an example, consider a configuration in which the number of magnetic poles of the motor 10 of the present embodiment is eight, that is, a configuration having eight magnets 18 . In this case, the prime factor of eight, which is the number of magnetic poles of the motor 10, is two. Therefore, the prime numbers that are not prime factors are 3, 5, 7, 11, 13, 17, 19, and so on. Integer multiples of prime numbers that are not prime factors are 3, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, and so on. Then, the number of lightening holes 26B is set to an integral multiple of the prime number which is not a prime factor.

Next, a configuration in which the number of magnetic poles of the motor 10 of the present embodiment is ten, that is, a configuration having ten magnets 18 will be examined. In this case, the prime factors of 10, which is the number of magnetic poles of the motor 10, are 2 and 5, respectively. Therefore, prime numbers that are not prime factors are 3, 7, 11, 13, 17, 19, and so on. Integer multiples of prime numbers that are not prime factors are 3, 6, 7, 9, 11, 12, 13, 14, 15, and so on. Then, the number of lightening holes 26B is set to an integral multiple of the prime number which is not a prime factor.

Next, a configuration in which the number of magnetic poles of the motor 10 of this embodiment is 12, that is, a configuration having 12 magnets 18 will be examined. In this case, the prime factors of 12, which is the number of magnetic poles of the motor 10, are 2 and 3, respectively. Therefore, prime numbers that are not prime factors are 5, 7, 11, 13, 17, 19, and so on. Integer multiples of prime numbers that are not prime factors are 5, 7, 10, 11, 14, 15, 17, 19, and so on. Then, the number of lightening holes 26B is set to an integral multiple of the prime number which is not a prime factor.

Next, a configuration in which the number of magnetic poles of the motor 10 of this embodiment is 16, that is, a configuration having 16 magnets 18 will be examined. In this case, the prime factor of 16, which is the number of magnetic poles of the motor 10, is two. Therefore, the prime numbers that are not prime factors are 3, 5, 7, 11, 13, 17, 19, and so on. Integer multiples of prime numbers that are not prime factors are 3, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, and so on. Then, the number of lightening holes 26B is set to an integral multiple of the prime number which is not a prime factor.

Next, a configuration in which the number of magnetic poles of the motor 10 of this embodiment is 20, that is, a configuration having 20 magnets 18 will be examined. In this case, the prime factors of 20, which is the number of magnetic poles of the motor 10, are 2 and 5, respectively. Therefore, prime numbers that are not prime factors are 3, 7, 11, 13, 17, 19, and so on. Integer multiples of prime numbers that are not prime factors are 3, 6, 7, 9, 11, 12, 13, 14, 15, 17, 17, 18, 19, 21, and so on. Then, the number of lightening holes 26B is set to an integral multiple of the prime number which is not a prime factor.

Further, as shown in FIG. 4, in the stator core 26 of the present embodiment, the maximum magnetic flux density inside the stator core 26 at the position closest to the facing portion 36 of the coil 16 in the plurality of lightening holes 26B forms the stator core 26. The shape, size, number and arrangement of the plurality of lightening holes 26B are set so that the magnetic flux density is less than the saturation magnetic flux density of the material. Specifically, first, when the stator core 26 is viewed from the axial direction, a virtual circle K circumscribing the plurality of lightening holes 26B is set. Next, the maximum magnetic flux density in a cylindrical cross section obtained by cutting the stator core 26 along the axial direction at a position corresponding to the virtual circle K will be examined. The shape, size, number and arrangement of the plurality of lightening holes 26B are set so that the maximum magnetic flux density is less than the saturation magnetic flux density of the material forming the stator core 26. FIG. In this embodiment, the maximum magnetic flux density is set to 80% or less of the saturation magnetic flux density so that the entire stator core 26 including the magnet 18 side is not magnetically saturated. Specifically, the maximum magnetic flux density is 1.44 T or less. In the configuration of an outer rotor type motor in which the coil 16 is arranged on the outer periphery of the stator core 26, a virtual circle K in which the plurality of lightening holes 26B are inscribed is set when the stator core 26 is viewed from the axial direction. The maximum magnetic flux density in a cylindrical cross section obtained by cutting the stator core 26 along the axial direction at a position corresponding to K should be examined.

In addition, in the present embodiment, the shape, size, and number of the plurality of lightening holes 26B are adjusted so that the volume of the portion of the stator core 26 on the outer peripheral side of the virtual circle K is larger than the volume of the plurality of lightening holes 26B. and placement are set.

(Action and effect of the present embodiment)
Next, the operation and effects of this embodiment will be described.

As shown in FIGS. 3, 6, 7, 10 and 11, in the motor 10 of the present embodiment, a U-phase coil connection body 46U and a V-phase coil connection body 46U forming part of the stator 14 A rotating magnetic field is generated in the inner periphery of the stator 14 by switching the energization of the 46V, W-phase coil connection body 46W. This causes the rotor 12 to rotate.

Here, in the motor 10 of the present embodiment, since the number of the long coils 34 and the number of the short coils 32 of the coil connections 46U, 46V, and 46W of each phase are set to the same number, The combined resistances of the coil connections 46U, 46V, and 46W are the same combined resistance. This makes it less likely that the coil connections 46U, 46V, and 46W of the respective phases will be electrically unbalanced. As a result, deterioration of the torque ripple of the motor 10 can be suppressed.

Further, in the motor 10 of the present embodiment, the coil end portions 38 of the long coils 34 and the coil end portions 38 of the short coils 32 are bent radially outward at right angles to the facing portion 36. , the coil end portion 38 of the long coil 34 and the coil end portion 38 of the short coil 32 are overlapped in the axial direction. As a result, an increase in the size of the stator 14 in the axial direction can be suppressed. As a result, it is possible to prevent the size of the motor 10 from increasing in the axial direction.

Furthermore, in the motor 10 of the present embodiment, the cross-sectional shape of the winding 30 forming the coil 16 is rectangular with the first direction (arrow A1 direction) as the longitudinal direction. In addition to this, the first direction of the winding 30 of the portion forming the opposing portion 36 of the short coil 32 and the opposing portion 36 of the long coil 34 is directed toward the magnet 18 side. As a result, the area of the portion of the winding 30 that faces the magnet 18 can be reduced while ensuring the cross-sectional area of the winding 30 . As a result, it is possible to suppress an increase in AC copper loss due to eddy currents generated in the opposing portion 36 while suppressing an increase in the electrical resistance of the winding 30 . In addition, in the motor 10 of the present embodiment, the opposing portion 36 has a single-layer structure along the radially inner surface of the stator core 26 . As a result, as shown in FIG. 8 , the shape of the facing portion 36 viewed from the axial direction can be easily formed into a curved shape corresponding to the radially inner surface of the stator core 26 . Thereby, the space factor can be improved.

Further, as shown in FIGS. 6, 7, 8 and 9, in the motor 10 of the present embodiment, in the manufacturing process of the coil 16, the pair of facing portions 36 and the coil ends on one side in the axial direction are formed in the coil 16. The portion 38 and the portion forming the coil end portion 38 on the other side in the axial direction (the laminated winding 30) are inseparably coupled in the second direction. As a result, workability is improved when the portions forming the coil end portion 38 on one side in the axial direction and the coil end portion 38 on the other side in the axial direction of the coil 16 are bent radially outward at substantially right angles. can be done.

Furthermore, in the motor 10 of the present embodiment, the number of layers of the windings 30 in the coil end portion 38 on one side in the axial direction of the coil 16 is smaller than the number of layers of the windings 30 in the coil end portion 38 on the other side in the axial direction. A pair of terminal portions 40 are arranged on one side in the axial direction in a state of being laminated. With this configuration, the length of the portion of the coil 16 around which the winding 30 is wound can be shortened. Thereby, an increase in the electrical resistance of the coil 16 can be suppressed.

Further, in the motor 10 of the present embodiment, a plurality of circumferential direction positioning portions 28D are provided on the outer peripheral side flange portion 28C of the insulator 28. As shown in FIG. Thereby, it is possible to improve workability when attaching the short coil 32 to the stator core 26 via the insulator 28 . In addition, the positions of the short coils 32 in the circumferential direction can be stabilized, and the short coils 32 can be more evenly arranged in the circumferential direction. A configuration in which only the circumferential positioning portion 28D for positioning the short coil 32 of one phase in the circumferential direction may be provided.

Furthermore, in the motor 10 of the present embodiment, the core engaging portion 28J of the insulator 28 engages the lightening hole 26B of the stator core 26, as shown in FIGS. Thereby, the circumferential displacement of the insulator 28 with respect to the stator core 26 can be restricted. Note that the core engaging portion 28J may be provided at one location in the circumferential direction, or may be provided at a plurality of locations in the circumferential direction.

Further, in the motor 10 of the present embodiment, a plurality of lightening holes 26B are formed in the outer peripheral portion of the stator core 26. As shown in FIG. Thereby, the weight of the stator core 26 can be reduced. As a result, the weight of the motor 10 can be reduced.

Furthermore, in the motor 10 of the present embodiment, the number of lightening holes 26B formed in the stator core 26 is set to an integer multiple of a prime number that is not a prime factor of the number of magnetic poles of the magnets 18 of the rotor 12 . As a result, the order of the cogging torque of the motor 10 can be increased. As a result, the amplitude of the cogging torque of the motor 10 can be reduced, and the noise and vibration of the motor 10 can be reduced.

Further, in the stator core 26 of the motor 10 of the present embodiment, the maximum magnetic flux density inside the stator core 26 at the position closest to the facing portion 36 of the coil 16 in the plurality of lightening holes 26B is the saturation magnetic flux density of the material forming the stator core 26. The shape, size, number and arrangement of the plurality of lightening holes 26B are set so as to be less than. As a result, the entire stator core 26 including the magnet 18 side is less likely to be magnetically saturated, and a decrease in the torque of the motor 10 can be suppressed.

In addition, in the present embodiment, the shape, size, and number of the plurality of lightening holes 26B are adjusted so that the volume of the portion of the stator core 26 on the outer peripheral side of the virtual circle K is larger than the volume of the plurality of lightening holes 26B. and placement are set. As a result, narrowing of the heat radiation path from the stator core 24 side to the housing 74 (see FIG. 2) side can be suppressed. That is, it is possible to suppress an increase in heat transfer resistance from the stator core 24 side to the housing 74 side.

Here, in a configuration in which the number of lightening holes 26B formed in the stator core 26 is determined, the number of magnetic poles of the magnet 18 is set to an integral multiple of a prime number that is not a prime factor of the number of lightening holes 26B. As a result, the same effect can be obtained as in the case where the number of lightening holes 26B formed in the stator core 26 is set to an integral multiple of a prime number that is not a prime factor of the number of magnetic poles of the magnets 18 of the rotor 12 as described above.

For example, consider a configuration in which the number of lightening holes 26B is determined to be eight. In this case, the prime factor of 8, which is the number of lightening holes 26B, is 2. Therefore, the prime numbers that are not prime factors are 3, 5, 7, 11, 13, 17, 19, and so on. Integer multiples of prime numbers that are not prime factors are 3, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, and so on. Then, the number of magnets 18 is set to an integral multiple of the prime number that is not the prime factor. Here, the number of magnets 18 is set to be an even number. Therefore, the number of magnets 18 is set to 6, 10, 12, 14, .

Next, a configuration in which the number of lightening holes 26B is determined to be nine will be examined. In this case, the prime factor of 9, which is the number of lightening holes 26B, is 3. Therefore, prime numbers that are not prime factors are 2, 5, 7, 11, 13, 17, 19, and so on. Integer multiples of prime numbers that are not prime factors are 2, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, and so on. Then, the number of magnets 18 is set to 2, 4, 6, 8, 10, 12, 14, 16 .

Next, a configuration in which the number of lightening holes 26B is determined to be ten will be considered. In this case, the prime factors of 10, which is the number of lightening holes 26B, are 2 and 5, respectively. Therefore, prime numbers that are not prime factors are 3, 7, 11, 13, 17, 19, and so on. Integer multiples of prime numbers that are not prime factors are 3, 6, 7, 9, 11, 12, 12, 13, 14, 15, and so on. Then, the number of magnets 18 is set to 6, 12, 14, .

Next, a configuration in which the number of lightening holes 26B is determined to be twelve will be considered. In this case, the prime factors of 12, which is the number of lightening holes 26B, are 2 and 3, respectively. Therefore, prime numbers that are not prime factors are 5, 7, 11, 13, 17, 19, and so on. Integer multiples of prime numbers that are not prime factors are 5, 7, 10, 11, 14, 15, 17, 19, 20, 21, 22, and so on. Then, the number of magnets 18 is set to 10, 14, 20, 22 .

Next, a configuration in which the number of lightening holes 26B is determined to be 21 will be examined. In this case, prime factors of 21, which is the number of lightening holes 26B, are 3 and 7, respectively. Therefore, the prime numbers that are not prime factors are 2, 5, 11, 13, 17, 19, and so on. Integer multiples of prime numbers that are not prime factors are 2, 4, 5, 6, 8, 10, 11, 12, 13, 14, 15, 16, and so on. Then, the number of magnets 18 is set to 2, 4, 6, 8, 10, 12, 14, 16 .

(Motors of Second to Nineteenth Embodiments)
Next, with reference to FIGS. 16 to 35, configurations of motors of second to nineteenth embodiments, which can achieve weight reduction in the same manner as the motor 10 of the first embodiment, will be described. In the motors of the second to nineteenth embodiments, members and portions corresponding to the motors of the embodiments already described are denoted by the same reference numerals as the members and portions corresponding to the motors of the embodiments already described. , the description may be omitted.

(Motor of Second Embodiment)
As shown in FIG. 16 , in the motor 90 of the second embodiment, a plurality of lightening grooves 26C as lightening portions are formed in the outer peripheral portion of the stator core 26 . The lightening groove 26C is formed in a groove shape that is open radially outward and is formed along the axial direction. The lightening groove 26</b>C is formed continuously from one axial end to the other axial end of the outer peripheral portion of the stator core 26 . The edge shape of the lightening groove 26C when viewed from the axial direction is U-shaped. Moreover, the plurality of lightening grooves 26C are arranged at regular intervals along the circumferential direction. Also, the number of lightening grooves 26</b>C is set to an integral multiple of a prime number that is not a prime factor of the number of magnetic poles of the magnets 18 of the rotor 12 . The weight of the motor 90 of the second embodiment can also be reduced in the same manner as the motor 10 of the first embodiment.

(Motor of the third embodiment)
As shown in FIG. 17, the stator core 26, which constitutes a part of the motor of the third embodiment, is formed by axially laminating core forming members 92 spirally formed along the axial direction. ing. A plurality of lightening portion forming portions 92A that are open radially outward are formed on the outer peripheral portion of the core forming member 92 . In a state in which the core forming members 92 are laminated in the axial direction, the circumferential position of the lightening portion forming portion 92A of one layer and the circumferential position of the lightening portion forming portion 92A of the other layer are are arranged in the same position. Thus, in a state in which the core forming members 92 are stacked in the axial direction, the lightening grooves 26C are formed by the plurality of lightening portion forming portions 92A. Also in the motor of the third embodiment, weight reduction can be achieved in the same manner as the motor 10 of the first embodiment. The number and positions of the lightening portion forming portions 92A are preferably set so that a plurality of lightening grooves 26C are formed.

(Motor of the fourth embodiment)
As shown in FIG. 18 , in the motor 94 of the fourth embodiment, fillers 96 are arranged inside the plurality of lightening holes 26B formed in the stator core 26 . This filler 96 is formed using a material lighter than the stator core 26 . As an example, the filler 96 is made of a resin material, a resin material mixed with glass fiber or the like, aluminum or the like. Note that the filler 96 may be poured into the lightening hole 26B in a melted state. Further, the filling material 96 may be formed in a rod shape and press-fit into the lightening hole 26B. In addition, in this embodiment, the filling material 96 is not disposed in the lightening hole 26B with which the core engaging portion 28J of the insulator 28 is engaged. The weight of the motor 94 of the fourth embodiment can also be reduced in the same manner as the motor 10 of the first embodiment. Further, by forming the filler 96 using a material having a higher thermal conductivity than the stator core 26, the heat dissipation of the motor 94 can be enhanced.

(Motor of the fifth embodiment)
As shown in FIGS. 19 and 20, in the stator core 26 of the motor of the fifth embodiment, a plurality of lightening grooves 26C are formed on both sides of the outer circumference of the stator core 26 in the axial direction. That is, in the stator core 26 of the motor of the fifth embodiment, the plurality of lightening grooves 26C are not formed in the axially central portion of the outer peripheral portion of the stator core 26 . The weight of the motor of the fifth embodiment can also be reduced in the same manner as the motor 10 of the first embodiment.

(Motor of the sixth embodiment)
As shown in FIG. 21, in the stator core 26 of the motor of the sixth embodiment, the intervals between the lightening grooves 26C adjacent in the circumferential direction are set at uneven intervals in a portion of the stator core 26. As shown in FIG. More specifically, in the stator core 26 of the motor of the sixth embodiment, the interval between the lightening grooves 26C adjacent to each other in the circumferential direction is set to θ in most of the outer peripheral portion of the stator core 26 . In a portion of the stator core 26 shown in FIG. 21, the interval between the lightening grooves 26C adjacent in the circumferential direction is set to θ+α or θ−α. The weight of the motor of the sixth embodiment can also be reduced in the same manner as the motor 10 of the first embodiment. In addition, by setting the interval between the lightening grooves 26C adjacent in the circumferential direction to be uneven in a portion of the stator core 26, the cogging torque characteristics of the motor can be adjusted. In addition, at a plurality of locations of the stator core 26, the intervals between the lightening grooves 26C adjacent to each other in the circumferential direction may be set at unequal intervals.

(Motor of the seventh embodiment)
As shown in FIG. 22 , in the stator core 26 of the motor of the seventh embodiment, the circumferential width of the hollowed grooves 26C is set unevenly in a portion of the stator core 26 . That is, in the stator core 26 of the motor of the seventh embodiment, the volume inside the hollowed grooves 26C is set unevenly in a portion of the stator core 26. As shown in FIG. Specifically, in the stator core 26 of the motor of the seventh embodiment, the width of the lightening groove 26C in the circumferential direction is set to W in most of the outer peripheral portion of the stator core 26 . In a portion of the stator core 26 shown in FIG. 22, the circumferential width of the lightening groove 26C is set to W+α or W−α. The weight of the motor of the seventh embodiment can also be reduced in the same manner as the motor 10 of the first embodiment. In addition, by setting the circumferential width of the lightening groove 26C unevenly in a portion of the stator core 26, the cogging torque characteristic of the motor can be adjusted. In addition, the circumferential width of the lightening grooves 26</b>C may be set unevenly at a plurality of locations of the stator core 26 .

(Motor of the eighth embodiment)
As shown in FIG. 23, the stator core 26 of the motor of the eighth embodiment has a two-part split structure in the circumferential direction. The stator core 26 of the motor of the eighth embodiment is formed by laminating plate-shaped core forming members in the axial direction. A configuration in which the core forming members are laminated in the axial direction will be described in detail in embodiments described later.

FIG. 24 shows an enlarged view of part of the stator core 26 of the motor of the eighth embodiment. As shown in this figure, the stator core 26 is a dust core formed by compressing magnetic particles 98 having insulating coatings 98A on their surfaces. The weight of the motor of the eighth embodiment can also be reduced in the same manner as the motor 10 of the first embodiment.

(Motors of the ninth to eleventh embodiments)
As shown in FIGS. 25, 26 and 27, the stator core 26 of the motor of the ninth to eleventh embodiments is formed by stacking annular core forming members 92 in the axial direction. ing. 25, 26 and 27, the core forming member 92 is shown in a portion of the stator core 26. As shown in FIG. A plurality of lightening portion forming portions 92A that are open radially outward are formed on the outer peripheral portion of the core forming member 92 . 92 A of these lightening part formation parts are arrange|positioned at equal intervals along the circumferential direction. In a state in which the core forming members 92 are laminated in the axial direction, the circumferential position of the lightening portion forming portion 92A of one layer and the circumferential position of the lightening portion forming portion 92A of the other layer are are arranged in the same position. Thus, in a state in which the core forming members 92 are stacked in the axial direction, the plurality of lightening grooves 26C are formed by the plurality of lightening portion forming portions 92A.

Further, as shown in FIG. 25, in the stator core 26 of the motor of the ninth embodiment, the portions of the laminated core forming members 92 where the lightening portion forming portions 92A are not formed are crimped with the crimping portions 100. , the laminated core forming members 92 are integrated in the axial direction. As shown in FIG. 26, in the stator core 26 of the motor of the tenth embodiment, by laser-welding along the axial direction the portions of the laminated core forming members 92 where the lightening portion forming portions 92A are not formed, , the laminated core forming members 92 are integrated in the axial direction. Reference numeral 102 indicates the laser-welded portion. As shown in FIG. 27, in the stator core 26 of the motor according to the eleventh embodiment, the portions corresponding to the lightening portion forming portions 92A in the laminated core forming members 92 are axially laser-welded or adhesive is applied. is applied, the laminated core forming members 92 are integrated in the axial direction. Reference numeral 104 indicates a portion to which laser welding or adhesive is applied. Further, the laminated core forming members 92 may be integrated in the axial direction by an adhesive provided between respective layers of the laminated core forming members 92 .

In the motors of the ninth to eleventh embodiments described above, weight reduction can be achieved similarly to the motor 10 of the first embodiment. Here, in the stator core 26 shown in FIGS. 25 and 26, the laminated core forming members 92 are integrated in the axial direction by performing machining on the outer peripheral side of the virtual circle K. As shown in FIG. With this configuration, it is possible to reduce the influence of deterioration of magnetic properties due to machining, and to suppress a decrease in the torque of the motor 10 and an increase in cogging torque.

(Motors of the 12th to 18th embodiments)
As shown in FIGS. 28 to 34, the stator core 26 of the motor of the twelfth to eighteenth embodiments is formed by laminating core forming members 92 in the axial direction. A cutout portion forming portion 92A is formed on the outer peripheral portion of the core forming member 92 . 28 to 34 show a part of a cross section cut along a cylindrical surface that passes through the center of the lightening hole 26B and is concentric with the rotation axis. Moreover, this configuration can also be applied to the lightening groove 26C.

As shown in FIG. 28, in the stator core 26 of the motor of the twelfth embodiment, the dimensions of the lightening portion forming portions 92A of each layer are set to be the same. Further, in the stator core 26, the laminated core forming members 92 are integrated in the axial direction in a state in which the lightening portion forming portions 92A of the respective layers are arranged at the same position in the circumferential direction.

As shown in FIG. 29, in the stator core 26 of the motor of the thirteenth embodiment, the dimensions of the lightening portion forming portions 92A of each layer are set to be the same. Further, in the stator core 26, the laminated core forming members 92 are integrated in the axial direction in a state in which the positions of the recessed portion forming portions 92A of the respective layers in the circumferential direction are shifted in the circumferential direction at uneven pitches.

As shown in FIG. 30, in the stator core 26 of the motor of the fourteenth embodiment, the dimensions of the lightening portion forming portions 92A of the respective layers are set to different dimensions. Further, in the stator core 26, the laminated core forming members 92 are integrated in the axial direction in a state in which the positions of the recessed portion forming portions 92A of the respective layers in the circumferential direction are shifted in the circumferential direction at uneven pitches.

As shown in FIG. 31, in the stator core 26 of the motor of the fifteenth embodiment, the dimensions of the lightening portion forming portions 92A of the respective layers are set to be the same. Further, in the stator core 26, the positions of the lightening portion forming portions 92A of the respective layers are shifted in the circumferential direction so that the lightening holes 26B are inclined toward the one circumferential side as they move from the one axial side to the other axial side. In this state, the stacked core forming members 92 are integrated in the axial direction.

As shown in FIG. 32, in the stator core 26 of the motor of the sixteenth embodiment, the dimensions of the lightening portion forming portions 92A of each layer are set to be the same. Further, in this stator core 26, the lamination is performed in a state in which the positions of the lightening portion forming portions 92A of the respective layers are shifted in the circumferential direction so that the lightening holes 26B form a stepped shape from one side in the axial direction to the other side in the axial direction. The core forming members 92 are integrated in the axial direction.

As shown in FIG. 33, in the stator core 26 of the motor of the seventeenth embodiment, the dimensions of the lightening portion forming portions 92A of each layer are set to be the same. Further, in this stator core 26, the laminated core forming members 92 are axially arranged in a state in which the positions of the lightening portion forming portions 92A of the respective layers are shifted in the circumferential direction so that the lightening holes 26B are interrupted in the axial direction. directionally integrated.

As shown in FIG. 34, in the stator core 26 of the motor of the eighteenth embodiment, the dimensions of the lightening portion forming portions 92A of each layer are set to be the same. Further, in the stator core 26, the core forming members are laminated in a state in which the positions of the lightening portion forming portions 92A of the respective layers are shifted in the circumferential direction so that the lightening holes 26B are interrupted in the axial direction for each layer. 92 are axially integrated.

In the motors of the twelfth to eighteenth embodiments described above, weight reduction can be achieved similarly to the motor 10 of the first embodiment. Further, the cogging torque characteristics of the motor can be adjusted by appropriately changing the setting of the circumferential position and the circumferential width of the lightening portion forming portion 92A of each layer.

(Motor of the 19th embodiment)
As shown in FIG. 35, in the motor insulator 28 of the nineteenth embodiment, the shape of the core engaging portion 28J is formed in a shape that tapers toward the distal end side in the projecting direction. As a result, in the motor of the nineteenth embodiment, workability when engaging the core engaging portion 28J of the insulator 28 with the lightening groove 26C of the stator core 26 can be improved.

(Motor of the 20th embodiment)
As shown in FIGS. 36 and 37, the insulator 28 of the motor of the twentieth embodiment includes a plurality of first circumferential positioning portions 28E as circumferential positioning portions for positioning the short coils 32 in the circumferential direction, A plurality of second circumferential positioning portions 28F are provided as circumferential positioning portions for positioning the middle coil 48 in the circumferential direction. Here, the medium coil 48 is the coil 16 whose axial dimension is set to be larger than the axial dimension of the short coil 32 and smaller than the axial dimension of the long coil 34. . The configurations of the first circumferential positioning portion 28E and the second circumferential positioning portion 28F are the same as the circumferential positioning portion 28D (see FIG. 13). The plurality of first circumferential positioning portions 28E are arranged at equal intervals in the circumferential direction along the axial end surface covering portion 28B. The plurality of second circumferential positioning portions 28F are arranged at equal intervals in the circumferential direction at positions offset to one side in the axial direction with respect to the plurality of first circumferential positioning portions 28E. When viewed from one side in the axial direction, the plurality of second circumferential positioning portions 28F are arranged between a pair of circumferentially adjacent first circumferential positioning portions 28E.

By arranging the coil end portions 38 of the short coil 32 between the pair of first circumferential positioning portions 28E adjacent in the circumferential direction, the short coil 32 is positioned in the circumferential direction. It's becoming In addition, the coil end portions 38 of the middle coil 48 are arranged between a pair of second circumferential positioning portions 28F adjacent in the circumferential direction, so that the middle coil 48 is positioned in the circumferential direction. It's becoming Here, in a state in which the coil end portions 38 of the middle coil 48 are arranged between a pair of second circumferential positioning portions 28F adjacent in the circumferential direction, the coil end portions 38 of the middle coil 48 are positioned in the first circumferential positioning direction. It is in contact with the axial end surface of the portion 28E. As a result, the middle coil 48 is positioned in the axial direction. That is, the first circumferential positioning portion 28E serves as a first axial positioning portion 28G as an axial positioning portion that positions the middle coil 48 in the axial direction. When the long coil 34 is arranged along the stator core 26 via the insulator 28, the coil end portion 38 of the long coil 34 is in contact with the axial end surface of the second circumferential positioning portion 28F. Thereby, the long coil 34 is positioned in the axial direction. That is, the second circumferential positioning portion 28F serves as a second axial positioning portion 28H as an axial positioning portion that positions the long coil 34 in the axial direction.

In the motor of the present embodiment described above, by providing the first circumferential positioning portion 28E (first axial positioning portion 28G) and the second circumferential positioning portion 28F (second axial positioning portion 28H), each Workability can be improved when the coil 16 is attached to the stator core 26 via the insulator 28 .

(Motor of the 21st embodiment)
As shown in FIG. 38, in the motor 54 of the twenty-first embodiment, the stator core 26 is provided with small projections 26A as inter-winding portions arranged between a pair of opposing portions 36 adjacent in the circumferential direction. It is characterized by Here, Wt is the width dimension in the circumferential direction of the small projection 26A, Bs is the saturation magnetic flux density of the small projection 26A, Wm is the width dimension in the circumferential direction for one magnetic pole of the magnet 18, and residual magnetic flux of the magnetic compound forming the magnet 18. Let Br be the density. Then, the small protrusion 26A is formed using a magnetic material or a non-magnetic material satisfying the relationship Wt×Bs≦Wm×Br. As a result, the magnetic flux density of the stator 14 can be improved, magnetic saturation and magnetic flux leakage can be suppressed, and the torque of the motor 54 can be improved.

(Motor of the 22nd embodiment)
As shown in FIG. 39, in the motor 56 of the twenty-second embodiment, the magnet 18 of the rotor 12 has an intrinsic coercive force Hc of 400 [kA/m] or more and a residual magnetic flux density Br of 1.0 [T] or more. It is formed using a magnetic compound. When the magnet 18 is viewed from the axial direction, the angle formed by the direction of the magnetization easy axis 58 at the magnetic pole center of the magnet 18 and the radial direction (d-axis 60) is the direction and the diameter of the magnet 18 between the magnetic poles. The angle is set to be smaller than the angle formed with the direction (q-axis 62). Thereby, the magnetic flux density in the air gap with the stator 14 can be increased. As a result, the size and output of the motor 56 can be reduced, and the amount of the magnet 18 can be reduced.

(Motor of 23rd Embodiment, Motor of 24th Embodiment)
As shown in FIG. 40A, in the motor 64 of the twenty-third embodiment, the coil 16 side portion of one magnet 18 and the coil 16 side portion of the other magnet 18 that are adjacent in the circumferential direction are spaced apart in the circumferential direction. ing. An intervening portion 24D formed using a magnetic material is provided between a portion of one magnet 18 adjacent in the circumferential direction opposite to the coil 16 and a portion of the other magnet 18 opposite to the coil 16. intervening. Interposition part 24D is formed in one with rotor core 24 as an example.

As shown in FIG. 40B, in the motor 66 of the twenty-fourth embodiment, the coil 16 side portion of one magnet 18 and the coil 16 side portion of the other magnet 18 that are adjacent in the circumferential direction are spaced apart in the circumferential direction. ing. Also, the portion of one magnet 18 that is adjacent in the circumferential direction opposite to the coil 16 and the portion of the other magnet 18 that is opposite to the coil 16 are in contact with each other in the circumferential direction or slightly separated from each other.

In the motor 64 of the twenty-third embodiment and the motor 66 of the twenty-fourth embodiment configured as described above, the magnetic resistance between the magnets 18 adjacent in the circumferential direction can be reduced, and the magnetic flux density can be increased.

(Motor of the 25th embodiment)
As shown in FIG. 41 , the motor 68 of the twenty-fifth embodiment is a motor with a speed reducer having a speed reducer 70 . Most of the reduction gear 70 is arranged inside the rotor core 24 . The speed reducer 70 includes an internal gear 72 fixed to the rotating shaft 22 and an external gear 76 arranged radially outside the internal gear 72 and fixed to a housing 74 that supports the stator 14. there is The speed reducer 70 also includes a planetary gear 78 disposed between the internal gear 72 and the external gear 76 and meshing with the internal gear 72 and the external gear 76, a carrier 80 supporting the planetary gear 78, and the carrier 80. and a fixed output shaft 82 . In the motor 68 with this configuration as well, the rotation of the rotor 12 can be reduced by the reducer 70 and transmitted to the output shaft 82 .

(Motor of 26th embodiment and motor of 27th embodiment)
As shown in FIGS. 42 and 43, a motor 84 of the twenty-sixth embodiment and a motor 86 of the twenty-seventh embodiment are formed using short coils 32 and long coils 34 having the same configuration. In this case, by adjusting the circumferential length of the stator core 26 or the like, it is possible to manufacture a plurality of types of motors 84, 86 with different outputs and sizes using the short coils 32 and long coils 34 of the same configuration.

Note that the configurations of the motor 10 and the like in each embodiment described above can be combined with each other. This combination may be appropriately set in consideration of the output required for the motor, the physical size, and the like. Further, the configuration of the motor 10 and the like of each embodiment described above can be applied not only to the inner rotor type motor but also to the outer rotor type motor.

In the example described above, the pair of coil end portions 38 of the coil 16 are bent substantially perpendicularly to the axial end face side of the stator core 26, but the present invention is not limited to this. For example, in the example shown in FIG. 44, the coil end portion 38 on one side in the axial direction of the short coil 32 is bent substantially perpendicularly to the end face side in the axial direction of the stator core 26, and the coil end portion 38 on the other side in the axial direction is bent to the stator core. 26 is bent substantially perpendicularly to the opposite side. In addition, the coil end portion 38 on one side in the axial direction of the long coil 34 is bent substantially perpendicularly to the end face side in the axial direction of the stator core 26 , and the coil end portion 38 on the other side in the axial direction is bent on the side opposite to the stator core 26 . It has a configuration in which it is bent at a substantially right angle. In the example shown in FIG. 45, the coil end portion 38 on one side in the axial direction of the short coil 32 is bent substantially perpendicularly to the end face side in the axial direction of the stator core 26, and the coil end portion 38 on the other side in the axial direction is not bent. and Further, the coil end portion 38 on one side in the axial direction of the long coil 34 is not bent, and the coil end portion 38 on the other side in the axial direction is bent substantially perpendicularly to the side opposite to the stator core 26 . In this example, the end portion 40 of the coil 16 is inclined with respect to the axial direction. In the example shown in FIG. 46, the pair of coil end portions 38 of the short coil 32 are bent substantially perpendicularly to the axial end face side of the stator core 26, and the pair of coil end portions 38 of the long coil 34 are not bent. and Further, in the example shown in FIG. 47, the pair of coil end portions 38 of the short coil 32 are bent toward the axial end face side of the stator core 26 so as to be inclined with respect to the axial direction, and the pair of coil end portions of the long coil 34 are bent. The portion 38 is bent toward the axial end face side of the stator core 26 so as to be inclined with respect to the axial direction. As described above, whether or not to bend the pair of coil end portions 38 of the coil 16, the direction of bending, and the angle of bending may be appropriately set in consideration of the physical size required for the motor. Further, as shown in FIG. 48 , the one axial end and the other axial end of the magnet 18 are connected to the coil end 38 on the one axial side and the coil end 38 on the other axial side. It is preferable that they are arranged so as to face each other in the radial direction. As a result, it is possible to increase the output and reduce the size of the motor.

Alternatively, as shown in FIG. 49, the winding 30 forming the coil 16 may be composed of two winding structures 88 stacked in the second direction (arrow A2 direction). Furthermore, as shown in FIG. 50, the winding 30 forming the coil 16 may be composed of two winding structures 88 stacked in the first direction (arrow A1 direction). Alternatively, as shown in FIG. 51, the windings 30 forming the coil 16 may be composed of four winding structures 88 stacked in the first direction and the second direction.

In each of the embodiments described above, the configuration in which the side on which the magnet 18 is provided is the rotor 12 (rotor) and the side on which the coil 16 is provided is the stator 14 (stator) has been described. 1 can also be applied to a configuration in which the side on which the coil 16 is provided is the rotor 12 (rotor) and the side on which the magnet 18 is provided is the stator 14 (stator). Further, it goes without saying that the configuration of the present disclosure can also be applied to a generator whose rotor is rotated by an external force.

An embodiment of the present disclosure has been described above, but the present disclosure is not limited to the above, and can be implemented in various modifications other than the above without departing from the scope of the present disclosure. is of course.

10 motor, 12 rotor (rotating body), 16 coil, 18 magnet, 26 stator core (core), 28 insulator, 28D circumferential positioning part, 28E first circumferential positioning part (circumferential positioning part), 28F second circumferential direction positioning portion (circumferential positioning portion), 28G first axial positioning portion (axial positioning portion), 28H second axial positioning portion (axial positioning portion), 28J core engaging portion, 28K radial outer flange portion ( axial direction reference portion), 28L notch portion (circumferential direction reference portion), 26B lightening hole (lightening portion), 26C lightening groove (lightening portion), 30 winding, 36 facing portion, 38 coil end portion, 54 motor, 56 motor, 64 motor, 66 motor, 68 motor, 74 housing (core support member), 84 motor, 86 motor, 90 motor, 92 core forming member, 92A hollowed portion forming portion, 94 motor, 96 filler, K virtual circle

Claims (15)

a rotating body (12) having a magnet (18) and rotatably supported;
Each is formed by winding a conductive winding (30) in a ring, and a part of the winding is arranged side by side in the circumferential direction and arranged to face the center of the magnet in the axial direction in the radial direction. and coil end portions (38) forming portions on one side and the other side in the axial direction with respect to the facing portion, respectively, and a plurality of coils arranged annularly in the circumferential direction. a coil (16);
The facing portions of the plurality of coils are arranged along the inner peripheral surface or the outer peripheral surface, and the coil end portion on one side in the axial direction of the plurality of coils and the coil end portion on the other side in the axial direction of the plurality of coils. a core (26) in which at least one of the coil end portions is arranged along an end face in the axial direction, and lightening portions (26B, 26C) are formed in a portion opposite to the facing portion; with
The shape, size, number and arrangement of the hollowed portions so that the maximum magnetic flux density inside the core at the position closest to the facing portion in the hollowed portion is less than the saturation magnetic flux density of the material forming the core. Motors (10, 54, 56, 64, 66, 68, 84, 86, 90, 94) where A plurality of the lightening portions are formed in the core at intervals in the circumferential direction,
2. The motor according to claim 1, wherein the number of said lightening portions is set to an integral multiple of a prime number that is not a prime factor of the number of magnetic poles of said magnet. A plurality of the lightening portions are formed in the core at intervals in the circumferential direction,
2. The motor according to claim 1, wherein the number of magnetic poles of said magnet is set to an integral multiple of a prime number that is not a prime factor of the number of said lightening portions. 4. The motor according to claim 2 or 3, wherein the intervals between the lightening portions adjacent in the circumferential direction are set at equal intervals over the entire circumference of the core. 4. The motor according to claim 2 or 3, wherein the intervals between the lightening portions adjacent in the circumferential direction are set at unequal intervals in at least a portion of the core. 4. The motor according to claim 2 or 3, wherein the volumes of the plurality of lightening portions are set unequal in at least a portion of the core. A motor according to any one of claims 1 to 6, wherein a filler (96) of a material lighter than the core is arranged inside the lightening portion. The core is formed by axially laminating plate-shaped core forming members (92) having a hollowed portion forming portion (92A) forming the hollowed portion,
Seeing the core from the axial direction, setting a virtual circle circumscribed or inscribed by the lightening portion on the side opposite to the facing portion,
The core forming member is machined at a portion of the core opposite to the facing portion with respect to the virtual circle, and the core forming member is integrated in a state of being laminated in the axial direction. The motor according to any one of claims 1 to 7. An insulator (28) is attached to the core to separate the core and the coil,
According to any one of claims 1 to 8, the insulator is provided with a core engaging portion (28J) that engages with the recessed portion to restrict displacement of the insulator in the circumferential direction with respect to the core. A motor according to any one of the preceding items. 10. The motor according to claim 9, wherein the insulator is provided with circumferential positioning portions (28D, 28E, 28F) for positioning the coils in the circumferential direction. 11. The motor according to claim 9, wherein the insulator is provided with axial positioning portions (28G, 28H) for positioning the coils in the axial direction. The core engaging portion is formed in a convex shape,
12. The motor according to any one of claims 9 to 11, wherein the shape of the core engaging portion is formed in a shape that narrows toward the distal end side in the projecting direction. further comprising a core support member (74) on which the core is held;
The insulator includes an axial reference portion (28K) projecting toward the side opposite to the rotating body with respect to the surface of the core opposite to the rotating body,
13. The motor according to any one of claims 9 to 12, wherein the core is axially positioned with respect to the core support member by abutting the axial reference portion on the core support member. The insulator includes a circumferential reference portion (28L),
14. The motor according to claim 13, wherein the core is positioned in the circumferential direction with respect to the core support member by engaging the circumferential reference portion with the core support member. Seeing the core from the axial direction, setting a virtual circle circumscribed or inscribed by the lightening portion on the side opposite to the facing portion,
15. The motor according to any one of claims 1 to 14, wherein a volume of a portion of the core on a side opposite to the facing portion with respect to the virtual circle is set larger than a volume of the lightening portion. .

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