JP4444737B2 - Brushless motor and motor for power steering device - Google Patents

Description

  The present invention relates to a brushless motor and a motor for a power steering device.

  Conventionally, as a motor for a power steering apparatus for assisting the operation of a vehicle steering shaft connected to a steering wheel of a vehicle, there is a direct current motor in which a magnet is fixed to a housing (yoke) (see Patent Document 1). . However, such a motor for a power steering device is disposed near the road surface, and there is a possibility that a stepping stone impact may be applied, and the magnet is vulnerable to impact (easy to break), so it is necessary to increase the rigidity of the housing. is there. Therefore, it is necessary to form the housing with a highly rigid iron material or to increase the plate thickness. This causes the power steering device motor to become heavier than the current vehicle that is required to be lighter.

  Therefore, it is conceivable to employ a brushless motor having a stator fixed to the inner periphery of the housing and a rotor housed inside the stator as the motor for the power steering device. The stator of such a brushless motor includes a stator core (core) having an annular portion that is fixed to the inner periphery of the housing and teeth portions that are radially arranged with the radially outer end connected to the annular portion. As such a stator core, there is one in which divided core portions having a shape divided for each tooth portion are connected in a ring shape. In such a stator (stator core), by winding the winding around the tooth portion before connecting the split core portions in an annular shape, the winding can be easily wound without the adjacent teeth portion interfering with each other. be able to.

And as such a stator core, the 1st and 2nd lamination | stacking member from which the length of the circumferential direction edge part corresponding to a cyclic | annular part differs is laminated | stacked alternately, and the circumferential direction edge part of a division | segmentation core part repeats an unevenness | corrugation. (For example, refer to Patent Document 2). The adjacent divided core portions are arranged so that the concave and convex portions of the circumferential end portions fit each other (that is, the convex portions overlap each other), and the pin is penetrated in the axial direction in the overlapping convex portions. To form a stator core. In such a stator, since the convex portions of the adjacent divided core portions overlap in the axial direction with a plurality of divided core portions arranged in an annular shape (since there is no linear gap in the axial direction), The magnetic resistance is reduced and the magnetic circuit is improved. Moreover, since the convex portions overlap in the axial direction, the divided core portions are prevented from being displaced in the axial direction.
Japanese Patent No. 3059059 JP-A-7-222383

  However, in the brushless motor (stator) as described above, since the winding is wound around the separated divided core parts (not connected by pins), the divided core parts are arranged annularly after the winding process. A process of fitting the irregularities to each other is required, and handling of the divided core parts separated into the number of teeth parts (for example, 12) becomes complicated. In addition, since the adjacent divided core portions are connected by pins and their relative movement is restricted, the number of parts and assembly man-hours increase.

  An object of the present invention is to provide a brushless motor that can easily wind a winding, can be easily circularized after winding, and can easily regulate the relative movement of the split core portion, and The object is to provide a motor for a power steering apparatus.

According to a first aspect of the present invention, there is provided a brushless motor including a stator fixed to the inner periphery of a substantially cylindrical housing, and a rotor accommodated inside the stator, wherein the stator is an inner periphery of the housing. And a core having a radially outer end connected to the annular portion and a radially disposed tooth portion, the core being divided annular portions obtained by dividing the annular portion in the circumferential direction; The divided annular portion includes a plurality of divided core portions extending in a substantially orthogonal direction, and the divided core portion is formed by alternately laminating first and second laminated members, One end in the circumferential direction corresponding to the divided annular portion of the laminated member is formed to be longer from the tooth portion than the other end in the circumferential direction, and radially outward of the one end in the circumferential direction is half in the circumferential direction when viewed from the axial direction. A protruding circle that is less than a circle A convex arc convex portion is formed, and an arc concave portion having an arc concave shape is formed in the circumferential direction on the radially outer side of the other end in the circumferential direction, and one end in the circumferential direction corresponding to the divided annular portion of the second laminated member is a circumference. The length from the teeth portion is shorter than the other end in the direction, and a circular arc concave portion is formed in the circumferential direction when viewed from the axial direction on the radially outer side of the same circumferential direction. An arc-shaped convex portion that protrudes less than a semicircle in the circumferential direction is formed on the outer side, and the arc-shaped concave portion of the divided core portion adjacent to the arc-shaped convex portion in a state where a plurality of the divided core portions are arranged. The circular convex portion and the circumferential end surface of the circular arc recess constitute a rotation guide surface that guides the rotation of the adjacent divided core portion, and are radially inward from the circular arc protrusion and the circular arc recess. The circumferential end faces of the divided core parts abut at the end position of rotation of the divided core parts adjacent to each other. Constitute the end contact surface, a plurality of the divided core portions by being fitted in the housing arranged in a ring, and the like move their relative is restricted.

According to a second aspect of the present invention, in the brushless motor according to the first aspect, the plurality of divided core portions arranged annularly with the housing are fixed by shrink fitting.

According to a third aspect of the present invention, in the brushless motor according to the first or second aspect , the housing is made of a material having a larger linear expansion coefficient than the core.

A fourth aspect of the present invention is a power steering apparatus motor in which the rotor in the brushless motor according to any one of the first to third aspects is for assisting an operation of a vehicle steering shaft. To do.

(Function)
According to the first aspect of the present invention, the arc convex portions are fitted into the arc concave portions of the adjacent divided core portions in a state where the plurality of divided core portions are arranged, and the arc convex portions of the adjacent divided core portions (arc Since the portions protruding in the circumferential direction from the recesses overlap in the axial direction, the magnetic resistance between the adjacent divided annular portions is reduced, and the magnetic circuit is improved. Further, the split core portions are prevented from being displaced in the axial direction. Further, one end in the circumferential direction corresponding to the divided annular portion of the first laminated member is formed to be longer from the tooth portion than the other circumferential end, and one end in the circumferential direction corresponding to the divided annular portion of the second laminated member is circumferential. The length from the teeth portion is shorter than the other end. Therefore, there is a radially inner portion where the circular convex portion at one circumferential end corresponding to the divided annular portion of the first laminated member is not formed, and an arc convex portion at the other circumferential end corresponding to the divided annular portion of the second laminated member. Even in the radially inner portion that is not formed, it overlaps in the axial direction, so that the magnetic resistance between adjacent divided annular portions is further reduced, and the magnetic circuit is further improved. Further, the split core portions are further prevented from being displaced in the axial direction.

  In addition, with the plurality of divided core portions arranged, the arc convex portions are fitted into the arc concave portions of the adjacent divided core portions, and the circumferential core end surfaces of the arc convex portions and the arc concave portions are rotated. Since the rotation guide surface to guide is comprised, the adjacent division | segmentation core part can be rotated easily, and it can be set as the state which expanded the space | interval of the front-end | tip parts of an adjacent teeth part. As a result, by winding the windings in a state where the interval is widened, the windings can be easily wound without the adjacent teeth portions interfering with each other. In addition, it is possible to easily form a ring by simply rotating the divided core portion around which the winding is wound.

  Furthermore, in order to constitute the terminal contact surface in which the circumferential end surface radially inward from the circular arc convex portion and the circular arc concave portion in the first and second laminated members contacts at the terminal end position of rotation of the adjacent divided core portion, The end contact surface comes into surface contact at the position, and it is possible to prevent the contact portion at the end position from being damaged at the time of closing when the distance between the tips of adjacent teeth portions is narrowed. In addition, since the plurality of split core portions are arranged in an annular shape and are fitted in the housing, even if an external force is applied from the outside in the radial direction, the end contact surface is in surface contact and is thus firmly supported by the end contact surface. As a result, the roundness of the annular portion is difficult to decrease.

  Further, since the plurality of divided core portions are arranged in a ring and are fitted in the housing, their relative movement (the rotation and the movement in the radial direction) is restricted, so that the relative movement is particularly restricted. This means, for example, pins as in the prior art, welding of the divided annular portions, and the like are not required.

  Furthermore, since the arc convex part protrudes in less than a semicircle in the circumferential direction and there are few protrusions in the circumferential direction of the arc convex part, the axial distance between the arc convex parts that are arranged in parallel in the axial direction in each divided core part The dimensional accuracy of (the gap) becomes high (if there are many protrusions in the circumferential direction of the arc-shaped convex part, the tip part is easily displaced in the axial direction, but the displacement is difficult). Therefore, for example, when the split core portions are moved in the axis-orthogonal direction and the arc convex portions are overlapped with each other (when the arc convex portions are fitted into the arc concave portions), assembling becomes easy.

According to the second aspect of the present invention, since the plurality of divided core portions arranged in a ring with the housing are fixed by shrink fitting, the plurality of divided core portions arranged in a ring form from the radially outer side. The connection is strengthened by receiving a large external force.

According to the invention described in claim 3 , since the housing is made of a material having a larger linear expansion coefficient than the core, a large stress may be generated in the core due to contraction of the housing. Deformation can be suppressed. Moreover, shrink fitting can be performed easily.

According to the fourth aspect of the present invention, since the rotor is a motor for a power steering device that assists the operation of the vehicle steering shaft, the rotor is disposed in the vicinity of the road surface, and there is a risk that a stepping stone impact or the like is applied. . And in motors with magnets fixed to the housing, the magnets are vulnerable to shocks, so the housing needs to be made of a highly rigid iron material, but this is not necessary, and the housing is made of a lightweight material and thin in thickness. can do. Therefore, in addition to the effect of the invention according to any one of claims 1 to 3 , the reliability of the power steering device motor can be improved while reducing the weight of the motor for the power steering device (because the magnet is not damaged). .

According to the first to third aspects of the present invention, the winding can be easily wound, the annularization after the winding can be facilitated, and the relative movement of the divided core portion is easily regulated. The brushless motor which can be provided can be provided.

According to the fourth aspect of the present invention, the winding can be easily wound, the annularization after the winding can be facilitated, and the relative movement of the divided core portion is easily regulated. It is possible to provide a motor for a power steering device that can be used.

  Hereinafter, an embodiment in which the present invention is embodied in a motor for a power steering apparatus that is connected to a steering wheel of a vehicle (not shown) and assists the operation of a vehicle steering shaft will be described with reference to FIGS. As shown in FIG. 1, a brushless motor as a motor for a power steering device includes a stator 1 and a rotor 2 (not shown) having a magnet (not shown) arranged opposite to the stator 1 and housed inside the stator 1. , And a housing 3. The rotor 2 is connected to a vehicle steering shaft (not shown).

  The stator 1 is provided in a substantially cylindrical housing 3 and includes a stator core 6 as a core around which a winding 5 is wound via an insulator 4. The stator core 6 is made of an iron-based magnetic material, and the housing 3 is made of a lighter material than the stator core 6. The housing 3 is made of a material having a larger linear expansion coefficient than the stator core 6. In the present embodiment, the housing 3 is made of an aluminum-based metal.

  The stator core 6 includes a plurality of teeth 7 that are radially arranged and wound with the winding 5, and an annular portion 8 that is fixed to the inner periphery of the housing 3 by connecting the radially outer ends of the teeth 7. (See FIG. 12). In the present embodiment, twelve teeth portions 7 are formed at equiangular (30 degree) intervals.

  Specifically, as shown in FIGS. 4A to 4C, the stator core 6 has a plurality of shapes (this embodiment) that are allowed to rotate with each other in a shape divided in the circumferential direction (for each tooth portion 7). 12 pieces) of divided core portions 13. Each divided core portion 13 is formed by alternately laminating first laminated members 11 (see FIG. 2) as laminated members and second laminated members 12 (see FIG. 3).

  As shown in FIGS. 2 (a) and 2 (b), the first laminated member 11 includes a pre-stacked divided annular portion 11a extending in an arc shape, and a substantially orthogonal direction from the intermediate portion of the pre-stacked divided annular portion 11a (the arc-shaped axial center). And a pre-lamination tooth portion 11b extending in the direction). A pre-lamination protrusion 11c extending in the circumferential direction is formed at the tip of the pre-lamination tooth portion 11b. The pre-lamination tooth portion 11b is formed with a first fitting recess 11d in one of the plate thickness directions (axial directions) (upward in FIG. 2B) and the other in the plate thickness direction (FIG. 2 ( b) The first fitting convex portion 11e is formed in the lower side. The first fitting concave portion 11d and the first fitting convex portion 11e are formed side by side in the plate thickness direction, and two sets thereof are formed side by side in the extending direction of the pre-lamination tooth portion 11b.

  In addition, at one end portion (left end portion in FIG. 2) in the circumferential direction of the divided annular portion 11a before stacking, an arc convex portion 11f having a circular arc shape in the circumferential direction when viewed from the axial direction (see FIG. 2A). Is formed. In addition, an arc recess 11g having an arc recess shape in the circumferential direction when viewed from the axial direction (see FIG. 2 (a)) is provided at the other circumferential end (the right end in FIG. 2) of the annular portion 11a before lamination. Is formed. That is, when the plurality of first laminated members 11 are arranged laterally (see FIG. 2A) at both ends in the circumferential direction of the divided annular portion 11a before lamination, An arc convex portion 11f and an arc concave portion 11g are formed so as to allow the rotation of the one laminated member 11 to each other.

  The arc concave arc in the arc convex portion 11f and the arc concave portion 11g of the present embodiment includes the innermost point (radially innermost point) in the radial direction of the annular portion 8 on the circumference including the arc. Is set to Further, the end position of the rotation of the adjacent divided core portion 13 (when closed) is located on the radially inner side of the annular portion 8 from the circular arc convex portion 11f and the circular arc concave portion 11g at the circumferential end portion of the divided annular portion 11a before lamination. A circumferential contact surface 11h is formed as a terminal contact surface that makes contact at The circumferential contact surface 11h extends in the radial direction of the annular portion 8 (that is, is formed radially) so as to contact the circumferential direction at the end position of rotation. Further, the centers of the arc convex shape and the arc concave arc are set on an extension line of the circumferential contact surface 11h when viewed from the axial direction. In the present embodiment, the arc-shaped convex arc has a substantially semicircular shape. The concave arc is a 90 degree arc (1/4 of a circle). A linear portion 11 i extending radially outward of the annular portion 8 is formed on the radially outer side of the annular portion 8 from the circular arc recess 11 g at the other circumferential end of the pre-stacked annular portion 11 a.

  As shown in FIGS. 3A and 3B, the second laminated member 12 is formed symmetrically with the first laminated member 11. That is, the second laminated member 12 includes a pre-lamination divided annular portion 12a that extends in an arc shape, and a pre-lamination tooth portion 12b that extends in an approximately orthogonal direction (the arc-shaped axial center direction) from an intermediate portion of the pre-laminate divided annular portion 12a. Have. A pre-lamination protrusion 12c extending in the circumferential direction is formed at the tip of the pre-lamination tooth portion 12b. Further, the pre-lamination tooth portion 12b has a second fitting recess 12d formed on one side in the plate thickness direction (axial direction) (upward in FIG. 3B) and the other in the plate thickness direction (FIG. The second fitting convex part 12e is formed in b) in the lower part. The second fitting concave portion 12d and the second fitting convex portion 12e are formed side by side in the plate thickness direction, and two sets thereof are formed side by side in the extending direction of the pre-lamination tooth portion 12b.

  In addition, the other end (the right end in FIG. 3) in the circumferential direction of the divided annular portion 12a before stacking is an arc-shaped convex portion that is arc-shaped in the circumferential direction when viewed from the axial direction (see FIG. 3 (a)). 12f is formed. In addition, an arc concave portion 12g having an arc concave shape is formed in the circumferential direction when viewed from the axial direction (see FIG. 3A) at one end portion (left end portion in FIG. 3) in the circumferential direction of the divided annular portion 12a before lamination. Has been. That is, when the plurality of second laminated members 12 are arranged laterally at both ends in the circumferential direction of the divisional annular portion 12a before lamination (see FIG. 3A), each is fitted (while guiding). An arc convex portion 12f and an arc concave portion 12g are formed so as to allow the two laminated members 12 to rotate.

  The arc concave arc in the arc convex portion 12f and the arc concave portion 12g of the present embodiment includes the innermost point (radially innermost point) in the radial direction of the annular portion 8 on the circumference including the arc. Is set to In addition, the end position of the rotation of the adjacent divided core portion 13 (when closed) is located on the radially inner side of the annular portion 8 from the circular arc convex portion 12f and the circular arc concave portion 12g at the circumferential end portion of the divided annular portion 12a before lamination. A circumferential abutment surface 12h is formed as a terminal abutment surface that abuts at. The circumferential contact surface 12h extends in the radial direction of the annular portion 8 (that is, is formed radially) so as to contact in the circumferential direction at the end position of rotation. Further, the centers of the arc convex shape and the arc concave shape are set on an extension line of the circumferential contact surface 12h when viewed from the axial direction. In the present embodiment, the arc-shaped convex arc has a substantially semicircular shape. The concave arc is a 90 degree arc (1/4 of a circle). A linear portion 12 i extending radially outward of the annular portion 8 is formed on the radially outer side of the annular portion 8 with respect to the circular arc recess 12 g at one circumferential end of the annular portion 12 a before lamination.

  Then, the first laminated member 11 and the second laminated member 12 are alternately laminated (5 layers in this embodiment), and as shown in FIG. A split core portion 13 having the split annular portion 13a and the tooth portion 7 composed of the pre-stacking tooth portions 11b and 12b is formed. At this time, in the first and second laminated members 11 and 12, the first fitting convex portion 11e is press-fitted and fitted into the second fitting concave portion 12d, and the second fitting convex portion 12e is fitted into the first fitting concave portion 11d. The split core portion 13 is formed by being fixed by press fitting. One end portion in the circumferential direction of the divided annular portion 13a in the divided core portion 13 has a shape in which irregularities are repeated by an arc convex portion 11f and an arc concave portion 12g, and the other end portion in the same circumferential direction is an arc convex portion 12f and an arc concave portion. It is made into the shape which repeats unevenness by 11g (refer FIG.4 (b)). And after the said unevenness | corrugations are mutually fitted, for example by the several division | segmentation core part 13 moving to the longitudinal direction (the left-right direction of FIG. 4 (a), and arrow X direction) of the division | segmentation annular part 13a, it is cyclic | annular By arranging, the division | segmentation annular part 13a forms the said annular part 8, and the said teeth part 7 is arrange | positioned radially (refer FIG. 1). In addition, since this assembling is a concave / convex fitting between the arc convex portions 11f and 12f, the fitting is compared with the linear concave / convex fitting disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 7-222383). Is easy. Further, in the state in which the plurality of divided core portions 13 are arranged, the concave and convex portions of the circumferential end portions of the divided annular portions 13a in the adjacent divided core portions 13 are fitted to each other, that is, the arc convex portions 11f and 12f ( Specifically, the portions protruding in the circumferential direction from the circular arc recesses 11g, 12g) are arranged so as to overlap in the axial direction. Further, in the state in which the plurality of divided core portions 13 are arranged, the rotation of the adjacent divided core portions 13 on the rotation guide surfaces which are arc-shaped curved surfaces of the arc convex portions 11f and 12f and the arc concave portions 11g and 12g is performed. You will be guided. That is, in this state, the rotation of the adjacent divided core portions 13 is allowed (guided by the rotation guide surface) by the arc concave shape and the arc convex shape. Further, the arc concave shape and the arc convex shape are not connected to each other.

  As shown in FIGS. 5 to 8, the insulator 4 includes first and second insulator members 21 and 22 having a shape corresponding to the divided core portion 13. The first and second insulator members 21 and 22 are made of an insulating resin material. The first and second insulator members 21 and 22 are arcuate end surfaces 21a and 22a disposed on one axial surface of the divided annular portion 13a, and inner circumferential end surfaces for covering the inner circumferential surface of the divided annular portion 13a. Parts 21b and 22b. The first and second insulator members 21 and 22 include end surface portions 21c and 22c for covering one axial surface of the tooth portion 7 and a pair of side surface portions 21d and 21d for covering both side surfaces of the tooth portion 7. 22d. The arc-shaped end surface portions 21a and 22a are formed so as to protrude in the axial direction so as to restrict the protrusion of the wound winding 5 to the outside in the radial direction. Grooves 21e and 22e are formed. Further, the end portion (the lower end portion in FIGS. 6 and 8) corresponding to the tip end portion of the tooth portion 7 in the end face portions 21c and 22c is restricted from protruding inward in the radial direction of the winding 5 to be wound. Inner restricting walls 21f and 22f that are erected in the axial direction are formed.

  Further, as shown in FIGS. 5 and 6, the first insulator member 21 has a position corresponding to the circumferential end of the divided annular portion 13a and the circumferential end (both ends) of the arcuate end surface portion 21a. An insertion hole 21g extending in the axial direction is formed. The insertion hole 21g is formed with a bowl-shaped notch 21h extending in the direction perpendicular to the axis (extending in the radial direction when viewed from the axial direction as shown in FIG. 6). In addition, as shown in FIG. 6, a pair of hook-shaped notches 21h in the first insulator member 21 of the present embodiment are separated from each other toward the inner regulating wall 21f side (lower side in FIG. 6). (In FIG. 6, it extends in a diagonally downward left direction and a diagonally downward right direction).

  Further, as shown in FIGS. 7 and 8, the second insulator member 22 is located at a position corresponding to the circumferential end of the divided annular portion 13a and at the circumferential end (both ends) of the arcuate end surface portion 22a. An insertion convex portion 22g extending in the axial direction is formed. The insertion protrusion 22g is formed with a hook-shaped protrusion 22h extending in the direction perpendicular to the axis (extending in the radial direction when viewed from the axis as shown in FIG. 8) at the tip thereof. The hook-shaped protruding portion 22h is capable of inserting the insertion convex portion 22g into the insertion hole 21g at a predetermined rotation angle (relative position is a predetermined angle) between the first insulator member 21 and the second insulator member 22, and at a predetermined time. The insertion convex portion 22g is formed so as not to be inserted into and removed from the insertion hole 21g except for the moving angle. That is, the hook-shaped protrusion 22h is formed so as to coincide with the hook-shaped notch 21h only at the predetermined rotation angle. In addition, as shown in FIG. 8, the pair of hook-shaped protrusions 22h in the second insulator member 22 of the present embodiment is separated so as to be closer to the inner regulation wall 22f side (lower side in FIG. 8) ( In FIG. 8, it extends in the diagonally downward left direction and diagonally downward right.

  As shown in FIG. 9, the predetermined rotation angle is such that 12 (6 in total) first and second insulator members 21 and 22 are arranged on the side corresponding to the tooth portion 7 (end surface portions 21c and 22c). Etc.) are set in an annularly arranged angle so that they face outward. At such a predetermined rotation angle, as shown in FIG. 10, the hook-shaped protrusion 22h coincides with the hook-shaped notch 21h, and the insertion protrusion 22g can be inserted into the insertion hole 21g. As a result, the first and second insulator members 21 and 22 are alternately arranged and rotatable with each other by inserting the insertion convex portions 22g into the insertion holes 21g in the state shown in FIG. Connected. In addition, a total of 12 (each 6) first and second insulator members 21 and 22 (the end portions of the first and second insulator members 21 and 22 at both ends) are inserted into the insertion holes 21g. And the insertion convex portion 22g is not formed.

  Further, FIG. 11 shows a total of twelve (six) first and second insulator members 21 and 22 such that the side corresponding to the tooth portion 7 (end surface portions 21c, 22c, etc.) faces inward. The state arranged in a circle is shown. This state (see FIG. 11) in the present embodiment is a state corresponding to the annular stator core 6 (divided core portion 13), that is, the stator core 6 (divided core portion 13) is mounted as shown in FIG. And finally placed. In this state (angle), the hook-shaped protrusion 22h does not coincide with the hook-shaped notch 21h (see a partially enlarged view in FIG. 11), so that the insertion protrusion 22g cannot be removed from the insertion hole 21g.

  The insulator 4 (first and second insulator members 21 and 22) configured as described above has a plurality of divided core portions 13 in a state in which the circular arc convex portions 11f and 12f overlap each other in the axial direction (see FIG. 4). By attaching to, the adjacent divided core portions 13 are rotatably connected. The axial centers of the insertion hole 21g and the insertion convex portion 22g are set to be the same as the axial centers of the circular arc convex portions 11f and 12f and the circular arc concave portions 11g and 12g, and the divided core portion 13 adjacent to the axial center. Can be rotated. Further, the insulators 4 (first and second insulator members 21 and 22) of the present embodiment are provided in a pair symmetrically in the axial direction of the divided core portion 13, that is, one and the other in the axial direction in a vertically symmetrical manner. Further, this connection has flexibility because the first and second insulator members 21 and 22 are made of a flexible resin material. That is, the positional relationship of the adjacent divided core portions 13 viewed from the axial direction can be changed by a slight amount in each direction by an external force or the like.

  And in the teeth part 7, in the state (open state) where the space | interval of the front-end | tip parts of the adjacent teeth part 7 was expanded, the end surface part 21c of the insulator 4, specifically, the 1st and 2nd insulator members 21 and 22, Winding 5 is wound through 22c and side surface parts 21d and 22d. In the present embodiment, the split core portions 13 are linearly arranged so that the teeth portions 7 extend in parallel, and the first and second insulator members 21 and 22 are linearly arranged. The winding 5 is wound in the state. In this state (angle), since the hook-shaped protrusion 22h does not coincide with the hook-shaped notch 21h, the insertion protrusion 22g cannot be removed from the insertion hole 21g. Therefore, when winding the winding 5, the connection between the first and second insulator members 21 and 22 is maintained, and at least one of the first insulator member 21 and the second insulator member 22 is partially detached from the stator core 6. It is prevented that this occurs (shift in the axial direction).

  As shown in FIG. 1, the plurality of split core portions 13 around which the windings 5 are wound are fitted into the housing 3 in an annularly arranged state (closed state), so that their relative movement is performed. Is regulated. That is, the outer periphery of the plurality of divided core portions 13 arranged in an annular shape (the outer periphery of the annular portion 8) is brought into contact with the inner peripheral surface of the housing 3, and the arc convex portions 11f and 12f, the arc concave portions 11g and 12g, and When the circumferential contact surfaces 12h are engaged (contacted) with each other, the rotation and radial movement of the plurality of divided core portions 13 are restricted. Further, the housing 3 of the present embodiment and the plurality of divided core portions 13 arranged in an annular shape are fixed by shrink fitting. That is, the housing 3 is heated and expanded to widen the inner diameter, a plurality of divided core portions 13 arranged in an annular shape are fitted therein, the temperature is returned to room temperature, and the housing 3 is contracted to fix them. . Thereby, the outer periphery (the outer peripheral surface of the annular portion 8) of the plurality of divided core portions 13 arranged in an annular shape is in press contact (strongly pressed) with the inner peripheral surface of the housing 3. Thereby, the stator 1 fixed to the housing 3 is formed.

Next, characteristic effects of the above embodiment will be described below.
(1) Since the arc-shaped convex portions 11f and 12f of the adjacent divided core portions 13 are overlapped in the axial direction in a state where the plurality of divided core portions 13 are arranged, the magnetic resistance between the adjacent divided annular portions 13a is reduced and magnetism is reduced. The circuit is good. Further, the split core portions 13 are prevented from being displaced in the axial direction.

  Moreover, the divided cores adjacent to each other in the state where the plurality of divided core portions 13 are arranged by the arc convex shape or the arc concave shape of the arc convex portions 11f, 12f and the arc concave portions 11g, 12g in the first and second laminated members 11, 12. The rotation of the portion 13 is allowed (guided by the rotation guide surface). Therefore, the adjacent division | segmentation core part 13 can be rotated and it can be set as the state which expanded the space | interval of the front-end | tip parts of the adjacent teeth part 7. FIG. As a result, by winding the winding 5 in a state where the interval is widened, the winding 5 can be easily wound without the adjacent teeth portion 7 being in the way. In addition, it is possible to easily make the ring shape by simply rotating the divided core portion 13 around which the winding 5 is wound.

  In addition, since the plurality of divided core portions 13 are fitted into the housing 3 in a state of being annularly arranged, their relative movement (the rotation and movement in the radial direction) is restricted, and thus the relative movement is particularly preferable. For example, a pin as in the prior art, welding of the end portions of the divided annular portion 13a, or the like becomes unnecessary.

  Further, due to the arc convex shape or the arc concave shape of the arc convex portions 11f and 12f and the arc concave portions 11g and 12g, even if an external force is applied from the radially outer side or the direction slightly deviated from the radial direction, ), The external force can be received, the stress concentration is prevented, and the deformation of the stator core 6 is suppressed.

For these reasons, it is possible to manufacture a brushless motor (motor for a power steering device) having excellent characteristics at a low cost.
(2) The motor for the power steering device is disposed near the road surface, and there is a risk that a stepping stone impact or the like may be applied. And in a DC type motor with a magnet fixed to the housing, the magnet is vulnerable to shock, so it is necessary to form the housing from a highly rigid iron or the like. In the embodiment, it is an aluminum-based metal) and the plate thickness can be reduced. Therefore, it is possible to improve the reliability of the power steering device motor while reducing the weight of the motor for the power steering device as compared with a conventional DC motor or the like (because the magnet is not damaged).

  (3) The arc convex shape and the arc concave arc in the arc convex portions 11f and 12f and the arc concave portions 11g and 12g are the innermost points in the radial direction of the annular portion 8 on the circumference including the arc (the radially innermost point). Point). Therefore, the movement in the radial direction between the inner circumference of the housing 3 and the radially innermost point of the arc concave portions 11g, 12g is restricted on the arc convex portions 11f, 12f side. This makes it difficult for the arc concave portions 11g, 12g and the arc convex portions 11f, 12f in the adjacent divided core portions 13 to be displaced in the radial direction (the radial displacement is minimized even when the manufacturing accuracy is low). The roundness of can be increased.

  (4) The rotation of the adjacent divided core portions 13 on the radially inner side of the annular portion 8 from the circular arc convex portions 11f and 12f and the circular arc concave portions 11g and 12g at the circumferential ends of the divided annular portions 11a and 12a before lamination. Circumferential contact surfaces 11h and 12h are formed as end contact surfaces that contact at the end position (when closed). Therefore, the circumferential contact surfaces 11h and 12h come into surface contact at the terminal position. Therefore, it is possible to prevent a portion that contacts at the terminal position from being damaged when the gap between the tips of the adjacent teeth portions 7 is narrowed. In addition, the circumferential contact surfaces 11h and 12h are in surface contact with each other even when receiving an external force from the radially outer side by arranging the plurality of divided core portions 13 in an annular shape and being fitted in the housing 3, so that the circumferential contact It will be firmly supported by the surfaces 11h and 12h, and the roundness of the annular portion 8 will be difficult to decrease.

  (5) Circumferential contact surfaces 11h, 12h extending in the radial direction of the annular portion 8 (that is, formed in a radial manner) and contacting in the circumferential direction at the end position; did. Therefore, even if an external force is applied from the outside in the radial direction by being internally fitted in the housing 3 in a state where the plurality of divided core portions 13 are arranged in a ring shape, the circumferential contact surfaces 11h and 12h are firmly supported in the circumferential direction. As a result, the roundness of the annular portion 8 is further unlikely to decrease.

  (6) The centers of the circular arcs of the circular arc convex shape and the circular arc concave shape in the circular arc convex portions 11f and 12f and the circular arc concave portions 11g and 12g are set on the extended lines of the circumferential contact surfaces 11h and 12h when viewed from the axial direction. If it does in this way, the circumferential direction edge part of the cyclic | annular division | segmentation annular parts 11a and 12a before lamination | stacking in the 1st and 2nd lamination | stacking members 11 and 12 can be made into a shape without an acute angle part (part in which intensity | strength becomes weak especially). Therefore, it is possible to reduce the deformation of the end portions in the circumferential direction of the divided annular portions 11a and 12a before lamination.

  (7) Since the plurality of divided core portions 13 arranged in a ring with the housing 3 are fixed by shrink fitting, the plurality of divided core portions 13 arranged in a ring form a large external force from the outside in the radial direction (FIG. 12). (Refer to the broken arrows), the connection between them becomes stronger (the relative movement is more reliably regulated).

(8) Since the housing 3 is made of a material having a larger linear expansion coefficient than the stator core 6, it is possible to easily perform shrink fitting.
(9) The adjacent divided core portions 13 are connected so as to be rotatable by the first and second insulator members 21 and 22 (insulator 4) (while the circular arc convex portions 11f and 12f are overlapped in the axial direction). Is done. Therefore, handling when rotating the adjacent divided core portions 13 is facilitated.

The above embodiment may be modified as follows.
-In said embodiment, when the circular arc convex shape and circular arc concave circular arc in circular arc convex part 11f, 12f and circular arc recessed part 11g, 12g contain the radial direction innermost point of the annular part 8 on the circumference containing the circular arc. However, if the relative movement is restricted by being fitted in the housing 3, the arc may be changed so as not to include the radially innermost point.

  For example, it may be changed as shown in FIG. The stator core 31 (the teeth portion 31a and the annular portion 31b) shown in FIG. 13 includes a plurality of divided core portions 32, and each divided core portion 32 includes a first laminated member 41 and a second laminated member 42 as laminated members. Are alternately stacked. The first and second laminated members 41, 42 extend in a substantially orthogonal direction (the arc-shaped axial center direction) from the pre-stacked divided annular portions 41 a, 42 a extending in an arc shape and the intermediate portion of the pre-stacked divided annular portions 41 a, 42 a. It has teeth part 41b, 42b before lamination. FIG. 13 shows the first and second laminated members 41 and 42 that have already been assembled in the same manner as in the above embodiment, and the second laminated member 42 (the divided annular portion 42a before lamination and the tooth portion 42b before lamination). A state of being covered with the first laminated member 41 (located below the first laminated member 41) is illustrated.

  In the first laminated member 41, a circumferential end 41c (left end in FIG. 13) of the pre-lamination divided annular portion 41a is a pre-lamination tooth portion 41b (tooth portion 31a) from a circumferential other end 41d (right end in FIG. 13). Is formed long (circumferential length). And the circular arc convex part 41e which protrudes in less than a semicircle in the circumferential direction seeing from an axial direction is formed in the radial direction outer side of the circumferential direction one end 41c of the division | segmentation annular | circularion part 41a before lamination | stacking, and the other circumferential direction other end is formed. An arc recess 41f having an arc recess shape in the circumferential direction is formed on the outer side in the radial direction of 41d.

  In the second laminated member 42, one end 42c in the circumferential direction (left end in FIG. 13) of the pre-lamination divided annular portion 42a is a pre-lamination tooth portion 42b (tooth portion 31a) from the other circumferential end 42d (right end in FIG. 13). The length (circumferential direction length) from is formed short. An arc-convex arc convex portion 42e that protrudes less than a semicircle in the circumferential direction when viewed from the axial direction is formed on the radially outer side of the other circumferential end 42d of the pre-stacked annular portion 42a. A circular arc recess 42f is formed in the circumferential direction on the outer side in the radial direction of 42c.

  The plurality of divided core portions 32 composed of the first and second laminated members 41 and 42 are arranged in a state in which the arc convex portions 41e and 42e are fitted into the arc concave portions 41f and 42f of the adjacent divided core portion 32 to form an arc. The circumferential end surfaces of the convex portions 41e and 42e and the circular arc concave portions 41f and 42f constitute a rotation guide surface that guides the rotation of the adjacent divided core portions 32. In this state, of course, the arcs of the arc convex portions 41e and 42e and the arc concave portions 41f and 42f are arranged on the same circumference. Further, the circumferential end faces (circumferential one end 41c, 42c, circumferential other end 41d, 42d) radially inward from the arc convex portions 41e, 42e and the arc concave portions 41f, 42f in the first and second laminated members 41, 42 are provided. A circumferential contact surface (terminal contact surface) that contacts at the end position of rotation of the adjacent divided core portions 32 is configured.

  As in the above embodiment, the plurality of split core portions 32 wound with the windings are fitted into the housing in an annularly arranged state (closed state), so that their relative movement is prevented. Be regulated.

Even if it does in this way, the effect similar to the effect (1) of the said embodiment, (2), (4), (5), (7)-(9) can be acquired.
Further, in the first laminated member 41, the circumferential one end 41c of the pre-lamination divided annular portion 41a is formed to be longer than the pre-lamination tooth portion 41b than the circumferential other end 41d. One end 42c in the circumferential direction of the portion 42a is formed to have a shorter length from the pre-stacking tooth portion 42b than the other end 42d in the circumferential direction. Therefore, the radially inner portion where the arc-shaped convex portion 41e is not formed at the circumferential one end 41c of the pre-stacking annular portion 41a and the radial direction where the arc-shaped convex portion 42e is not formed at the other circumferential end 42d of the pre-stacking annular portion 42a. Since the inner portion also overlaps in the axial direction, the magnetic resistance between the adjacent divided annular portions 32a is further reduced, and the magnetic circuit is further improved. Further, the split core portions 32 are further prevented from being displaced in the axial direction.

  Furthermore, the arc convex portions 41e and 42e project in less than a semicircle in the circumferential direction, and the arc convex portions 41e and 42e have few protrusions in the circumferential direction. The dimensional accuracy of the axial distance (the gap) between the convex portions 41e and 42e becomes higher (the more the protrusion in the circumferential direction of the arc convex portion, the easier the tip portion to be displaced in the axial direction, but the displacement becomes difficult. ). Therefore, for example, as in the above embodiment, when the divided core portions 32 are moved in the direction perpendicular to the axis (longitudinal direction of the divided annular portion 32a) and the arc convex portions 41e and 42e are overlapped with each other (the arc concave portion 41f). , 42f when the arcuate convex portions 41e, 42e are fitted).

  In the above embodiment, the end abutment surface that abuts at the end position at the closing time extends in the radial direction of the annular portion 8 (that is, is formed radially), and the circumferential abutment surface abuts in the circumferential direction at the end position. Although it is set as 11h, 12h, it may be changed to another shape (for example, a surface inclined with respect to the radial direction of the annular portion 8) in surface contact at the terminal position. Even if it does in this way, the effect similar to the effect (1)-(4) of the said embodiment and (7)-(9) can be acquired.

  In the above embodiment, the centers of the arc convex and arc concave arcs in the arc convex portions 11f and 12f and the arc concave portions 11g and 12g are set on the extension lines of the circumferential contact surfaces 11h and 12h when viewed from the axial direction. However, it may be set at a position shifted from the extension line. Even if it does in this way, the effect similar to the effect (1)-(5) of the said embodiment and (7)-(9) can be acquired.

In the above embodiment, the housing 3 and the plurality of divided core portions 13 arranged in an annular shape are fixed by shrink fitting, but may be fixed by other methods (for example, press-fitting or the like).
In the above embodiment, the housing 3 is made of a material having a higher linear expansion coefficient than that of the stator core 6. However, the present invention is not limited to this, and may be changed to a material having substantially the same linear expansion coefficient, for example.

  In the above embodiment, the divided core portion 13 is configured by alternately laminating the first and second laminated members 11, 12 (41, 42), but the first and second laminated members 11, 12 (41, 42) may be placed in any number (including the part where the same member is continuously laminated), or one (one type of arc convex and concave portions) may be formed. For example, only the first laminated member 11) may be laminated to constitute the divided core portion. In the latter case, the arc convex portions of the adjacent split core portions do not overlap in the axial direction, but even if an external force is applied from the outside in the radial direction or the direction slightly deviated from the radial direction, An external force can be received by an arcuate curved surface (rotation guide surface), and effects such as prevention of stress concentration and, in turn, deformation of the stator core are suppressed.

  -The edge part of the division | segmentation annular part 13a (32a) in the adjacent division | segmentation core part 13 (32) of the said embodiment may be welded, and you may make it fit in the housing 3 after that. By doing so, it is possible to obtain a brushless motor in which the deformation of the stator core 6 (31) is further suppressed and the rigidity is further increased.

  In the above embodiment, the first and second insulator members 21 and 22 (insulator 4) connect the adjacent divided core portions 13 (32) so as to be rotatable. However, the rotation may be permitted. If possible, you may change to the insulator which is not connected (for example, the insulator member each fixed to the division | segmentation core part 13).

In the embodiment described above, the power steering device motor for assisting the operation of the vehicle steering shaft is embodied. However, the motor may be embodied in a brushless motor for other purposes.
The technical idea that can be grasped from the above embodiments will be described below together with the effects thereof.

(B) pre-Symbol end abutment surface, characterized in that the extending circumferentially in a radial direction of the annular portion is in contact with the circumferential contact surface. In this way, since the plurality of split core portions are arranged in an annular shape and are internally fitted in the housing, the circumferential contact surface comes into surface contact even when receiving an external force from the outside in the radial direction. It will be firmly supported in the circumferential direction, and the roundness of the annular portion will not be further lowered.

  (B) In the brushless motor described in (a) above, the center of the arc-shaped convex shape and the circular arc-shaped concave shape is on the extension line of the circumferential contact surface when viewed from the axial direction. motor. In this case, the circumferential end corresponding to the laminated member or the divided annular portions of the first and second laminated members has a shape without an acute angle portion (particularly a portion where the strength is weakened), and according to claim 3. The effects of the invention can be obtained.

FIG. 3 is a cross-sectional view of a main part of the brushless motor in the present embodiment. (A) The top view of the 1st laminated member in this Embodiment. (B) AA sectional drawing of (a). (A) The top view of the 2nd lamination member in this embodiment. (B) BB sectional drawing of (a). (A) The top view at the time of developing the stator core in this Embodiment. (B) Similarly front view. (C) Similarly perspective view. The perspective view of the 1st insulator member in this Embodiment. The top view of the 1st insulator member in this Embodiment. The perspective view of the 2nd insulator member in this Embodiment. The top view of the 2nd insulator member in this Embodiment. Explanatory drawing for demonstrating a 1st and 2nd insulator member. CC sectional drawing of FIG. Explanatory drawing for demonstrating a 1st and 2nd insulator member. The top view of the stator core in this Embodiment. The partially expanded plan view of the stator core in another example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Stator, 2 ... Rotor, 3 ... Housing, 6, 31 ... Stator core (core), 7, 31a ... Teeth part, 8, 31b ... Annular part, 11, 12, 41, 42 ... 1st and 2nd laminated member , 11f, 12f, 41e, 42e ... arc convex portion, 11g, 12g, 41f, 42f ... arc concave portion, 12h ... circumferential contact surface (terminal contact surface), 13, 32 ... split core portion, 13a, 32a ... Divided annular part.

Claims (4)

In a brushless motor comprising a stator fixed to the inner periphery of a substantially cylindrical housing, and a rotor accommodated inside the stator,
The stator includes a core having an annular portion that is fixed to the inner periphery of the housing and a teeth portion that is radially arranged with the radially outer end connected to the annular portion,
The core is composed of a plurality of divided core portions having a divided annular portion obtained by dividing the annular portion in the circumferential direction and the teeth portion extending in a substantially orthogonal direction of the divided annular portion,
The divided core portion is formed by alternately laminating first and second laminated members,
One end in the circumferential direction corresponding to the divided annular portion of the first laminated member is formed to be longer from the teeth portion than the other end in the circumferential direction. An arc convex arc convex portion protruding in less than a semicircle in the direction is formed, and an arc concave portion having an arc concave shape in the circumferential direction is formed on the radially outer side of the other circumferential end,
One end in the circumferential direction corresponding to the divided annular portion of the second laminated member is formed to have a shorter length from the tooth portion than the other end in the circumferential direction. A circular arc concave portion is formed in the direction, and a circular arc convex portion protruding in a circumferential direction with less than a semicircle is formed on the radially outer side at the other end in the circumferential direction.
In the state where a plurality of the divided core portions are arranged, the arc-shaped convex portions are fitted in the arc-shaped concave portions of the adjacent divided core portions, and the circumferential end surfaces of the arc-shaped convex portions and the arc-shaped concave portions are adjacent to each other. Terminal contact that constitutes a rotation guide surface that guides the rotation of the portion, and the circumferential end surface radially inward from the arc convex portion and the arc concave portion abuts at the rotation end position of the adjacent divided core portion Composing the surface,
A brushless motor characterized in that a plurality of the divided core portions are arranged in an annular shape and are fitted into the housing to restrict relative movement thereof. The brushless motor according to claim 1,
The brushless motor, wherein the plurality of divided core portions arranged in a ring shape with the housing are fixed by shrink fitting. The brushless motor according to claim 1 or 2,
The brushless motor is characterized in that the housing is made of a material having a larger linear expansion coefficient than the core. The motor for a power steering device, wherein the rotor in the brushless motor according to any one of claims 1 to 3 is for assisting an operation of a vehicle steering shaft.

Images