WO2009048181A1

WO2009048181A1 - Motor

Info

Publication number: WO2009048181A1
Application number: PCT/JP2008/069279
Authority: WO
Inventors: Toshinobu Shinohara; Kenichirou Hamagishi
Original assignee: Nidec Corporation
Priority date: 2007-10-09
Filing date: 2008-10-09
Publication date: 2009-04-16
Also published as: JP2009095137A; JP5305219B2

Abstract

A motor includes an annular armature 2 having nine teeth 211. One conducting wire is successively wound on the three teeth 211, thereby forming a coil group. Three coil groups are connected by delta connection. On upper surfaces of the insulators 22a and 22b, two grooves 221 for holding bus bars 24a to 24c are formed. The number of bus bars held by one insulator is two at the maximum in the radial direction. Accordingly, the space required for placing the bus bars on the armature can be reduced, and the radial and axial sizes of a motor 1 can be reduced.

Description

DESCRIPTION MOTOR

BACKGROUND OF THE INVENTION TECHNICAL FIELD

The present invention relates to an electric motor.

BACKGROUND ART

An inner-rotor electric motor includes a rotor portion with a permanent magnet which is placed on the inside of an annular armature so as to rotate. In such an inner-rotor electric motor, a wiring portion having a complicated structure for supplying a current to the armature is provided on the armature. For the purpose of simplifying the wiring portion for supplying a current to the armature, as disclosed in Patent Document 1, in an armature having nine salient magnetic poles, a single winding is successively wound in a forward direction, in an inverse direction, and in the forward direction, around the three salient magnetic poles arranged in a circumferential direction. Then, the three windings are connected by delta connection, thereby reducing the number of connections of end portions of the windings.

[Patent Document 1] Japanese Laid-Open Patent Publication 2006-191757

DISCLOSURE OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

Many polyphase motors utilize a bus bar unit as a wiring portion disposed on an armature. The bus bar unit is produced in such a manner that bus bars having connection terminals in respective phases are axially superposed, and then resin-molded. Such a bus bar unit has a certain degree of thickness in the axial direction, so that it is difficult to sufficiently reduce the axial height of a motor with the bus bar unit. Particularly, a motor used for an electrically operated slide door in a vehicle is required to drastically reduce the height thereof. For this reason, it is not preferred to use the bus bar unit. On the other hand, it is required that in order to ensure the flexibility of the design of the electrically operated slide door, the radial size of the motor should be reduced to be as small as possible.

The present invention has been conducted in view of the above-mentioned problems, and an object of the present invention is to provide a miniaturized motor by reducing a space required for disposing a wiring portion on an armature.

SOLUTION TO THE PROBLEMS

A motor according to an embodiment of the present invention includes: an annular armature; a rotor portion inserted into the armature; a bearing mechanism for supporting the rotor portion with respect to the armature in a rotatable manner with a center axis of the armature as the center; and a wiring portion, disposed on the armature, functioning as a supply path of a driving current to the armature.

The armature includes: a core having a plurality of teeth radially disposed around the rotor portion and a core back for magnetically coupling the outsides of the plurality of teeth; a plurality of insulators for covering the plurality of teeth, respectively; and a plurality of coils formed by winding a conducting wire on the plurality of insulators.

The wiring portion has three wiring members disposed on the plurality of insulators on the outside of the plurality of coils, one wiringmember of the three wiring members extends in one direction of a circumferential direction from an external connecting portion disposed in an outer peripheral portion of the armature or on the outside of the peripheral portion of the armature, the other two wiring members of the three wiring members are radially arranged and extend in a direction opposite to the one direction of the circumferential direction from the external connecting portion, and the one wiring member does not overlap the two wiring members in the radial direction.

A motor according to another embodiment of the present invention includes: an annular armature; a rotor portion inserted into the armature; a bearing mechanism for supporting the rotor portion with respect to the armature in a rotatable manner with a center axis of the armature as the center; a wiring portion, disposed on the armature, functioning as a supply path of a driving current to the armature; and a substantially plate-shaped resin plate for covering the wiring portion.

The armature includes : a core having a plurality of teeth radially disposed around the rotor portion and a core back for magnetically coupling the outsides of the plurality of teeth; a plurality of insulators for covering the plurality of teeth, respectively; and a plurality of coils formed by winding a conducting wire on the plurality of insulators.

The wiring portion has three wiring members disposed on the plurality of insulators on the outside of the plurality of coils, one wiringmember of the three wiringmembers extends in one direction of a circumferential direction from an external connecting portion disposed in an outer peripheral portion of the armature or on the outside of the peripheral portion of the armature, the other two wiring members of the three wiring members are radially arranged and extend in a direction opposite to the one direction of the circumferential direction from the external connecting portion, and the one wiring member does not overlap the two wiring members in the radial direction.

The resin plate is joined to the plurality of insulators on the outside of the three wiring members.

EFFECTS OF THE INVENTION

According to the present invention, one wiring member does not overlap the other two wiring members in a radial direction, so that miniaturization of a motor can be attained.

BRIEF DESCRIPTION OF THE DRAWINGS

[Fig. 1] Fig. 1 is a longitudinal sectional view of a motor.

[Fig. 2] Fig. 2 is a bottom view of a stator cover.

[Fig. 3] Fig. 3 is a longitudinal sectional view of the stator cover.

[Fig. 4] Fig. 4 is a plan view of an upper cover.

[Fig. 5] Fig. 5 is a longitudinal sectional view of the upper cover.

[Fig. 6] Fig. 6 is a plan view of an armature and a bus bar.

[Fig. 7] Fig. 7 is a plan view showing a core of the armature.

[Fig. 8] Fig. 8 is a plan view showing the core and insulators of the armature.

[Fig.9] Fig.9 is a perspective view of an insulator component .

[Fig. 10] Fig. 10 is a perspective view of an insulator component .

[Fig. 11] Fig. 11 is a longitudinal sectional view sowing a first insulator and a split core.

[Fig. 12] Fig. 12 is a plan view showing an arrangement of the bus bar.

[Fig.13] Fig.13 is a perspective view of a bus bar for U-phase.

[Fig. 14] Fig.14 is an enlarged view of the vicinity of a rotor portion.

[Fig. 15] Fig. 15 is a perspective view of a rotor core. [Fig. 16] Fig. 16 is a perspective view of a sensor magnet. [Fig. 17] Fig. 17 is a perspective view of a resin plate. [Fig. 18] Fig. 18 is a bottom view of the resin plate. [Fig. 19] Fig. 19 is a longitudinal sectional view showing the vicinity of a terminal arrangement portion.

DESCRIPTION OF THE REFERENCE CHARACTERS

1 MOTOR

2 ARMATURE

3 ROTOR

4 BEARING MECHANISM 12 CONNECTOR PORTION 11 RESIN PLATE

21 CORE

22a FIRST INSULATOR

22b SECOND INSULATOR

23 COIL

24a to 24c BUS BARS

210 CORE BACK

211 GROOVE 225 PROJECTION Jl CENTER AXIS

BEST MODES FOR CARRYING OUT THE INVENTION

Fig. 1 is a longitudinal sectional view of a motor 1 of electrical type (hereinafter, referred to as ^λλa motor 1") according to a first embodiment of the present invention. Fig. 1 also shows part of the configuration on the backside of the section. In the figure, the section is shown without parallel-hatched lines. The motor 1 is employed as a driving source for an electrically operated slide door mounted on a vehicle. The motor 1 is mounted in a small space between an inner wall and an outer wall of the vehicle. In order to ensure a wide interior space of the vehicle, the motor 1 has a thin configuration in which the height thereof in a direction along a center axis Jl is smaller than an outer diameter. As shown in Fig. 1, the motor 1 is an inner-rotor motor which includes a substantially annular armature 2 with a center axis Jl as the center, a substantially columnar rotor portion 3 inserted into the armature 2, a bearing mechanism 4 for supporting the rotor portion 3 with respect to the armature 2 via a shaft 31 in a rotatable manner with the center axis Jl as the center (the center axis Jl also functions as a center axis of the armature 2) , a sensor portion 5 for sensing a rotational position of the rotor portion 2, a cover portion 10 for covering the armature 2, and a substantially plate-shaped resin plate 11 disposed on an upper face of the armature 2. A part of the resin plate 11 protrudes to an outside of the cover portion 10, and functions as part of a connector portion 12 having a terminal for electrical connection to an external power source.

The cover portion 10 includes a substantially cylindrical stator cover 13 with a bottom as a lower cover for covering a side face and a lower surface (i.e., a surface on the opposite side to the resin plate 11) of the armature 2, and a substantially plate-shaped upper cover 14 attached on the stator cover 13 for covering the resin plate 11. Thus, the cover portion 10 accommodates the armature 2 and the resin plate 11. In the following description, for the convenience, the side on which the upper cover 14 is disposed along the center axis Jl is referred to as an upper side, and the side on which the stator cover 13 is disposed is referred to as a lower side, but the center axis Jl does not necessarily agree with the direction of gravity.

The armature 2 includes a core 21 formed by laminating a plurality of thin silicon steel plates, an insulator 22 for covering the core 21, and a coil 23 wound on the insulator 22. On the armature 2, a plurality of bus bars 24 as wiring portions for supplying a driving current to the armature 2 are placed. The bus bars 24 are covered with the resin plate 11. The bearing mechanism 4 is constituted by a pair of ball bearings 41 and 42 arranged along the center axis Jl. The ball bearing 41 is held in a bearing holding portion 1313 disposed in the center of the stator cover 13. The ball bearing 42 is held in a bearing holding portion 143 disposed in the center of the upper cover 14. The sensor portion 5 includes a circuit board 51 and a sensor 52 as a magnetic-field sensing device such as a hall element . The sensor 52 is axially opposed to a sensor magnet 34 attached to the rotor portion 3. When the sensor 52 senses the magnetic field of the sensor magnet 34, the rotational position of the rotor portion 3 with respect to the armature 2 is detected.

Fig. 2 is a bottom view of the stator cover 13 of the cover portion 10. Fig. 3 is a longitudinal sectional view in a position indicated by arrow A in Fig. 2. As shown in Figs.2 and 3, the stator cover 13 includes a substantially disk-shaped bottom portion 131, a substantially cylindrical side-wall portion 132 extending upward from an outer periphery of the bottom portion 131, and a flange portion 133 expanding outward in a direction perpendicular to the center axis Jl from an upper end of the side-wall portion 132. The bottom portion 131 has a hole portion 1311 in the center portion thereof, and an annular protruding portion 1312 around the hole portion 1311 with the center axis Jl as the center. A shaft 31 shown in Fig. 1 is inserted into the hole portion 1311. The annular protruding portion 1312 protrudes upward. An inside portion of the annular protruding portion 1312 functions as the bearing holding portion 1313 for holding the ball bearing 41 of the bearing mechanism 4 shown in Fig. 1.

As shown in Fig. 3, in a position of the side-wall portion 132 for covering an outer side face of the armature 2 in which the connector portion 12 is placed, a cut-out portion 1321 is formed for passing the resin plate 11 and the bus bars 24 shown in Fig. 1 therethrough. On the side-wall portion 132, a plurality of projections 1322 which slightly project inward are disposed in four positions equally distributed in the circumferential direction. As shown in Fig. 1, the armature 2 is fixed to the stator cover 13 by press fitting (in combination with an adhesive as required) . The lower surface of the core 21 of the armature 2 abuts against the plurality of projections 1322, so that the armature 2 is positioned and supported. Accordingly, the axial position of the armature 2 can be easily fixed, and the vibration caused by the armature 2 can be prevented from being propagated to the cover portion 10.

As shown in Fig. 2, the flange portion 133 has a substantially triangle shape in which the three corners are rounded. Each of the three corner portions of the flange portion 133 has a screw hole 1331 for fixing the upper cover 14 shown in Fig. 1. A portion of the flange portion 133 is cut out together with the cut-out portion 1321 of the side-wall portion 132 in a position in which the connector portion 12 is disposed. The stator cover 13 can be produced inexpensively by press working of a thin plate member. If such a thin plate member is used, the axial height of the motor 1 can be reduced, and the plurality of projections 1322 can be easily formed by breaking and bending inward a part of the side-wall portion 132 by press working.

Fig. 4 is a plan view of the upper cover 14 for covering the upper surface of the armature 2. Fig. 5 is a sectional view of the upper cover 14 in a position indicated by arrow B in Fig. 4. The upper cover 14 has a substantially triangle shape similar to the flange portion 133 of the stator cover 13 shown in Fig. 2. Hole portions 144 are formed in three positions corresponding to the screw holes 1331 of the stator cover 13. The upper cover 14 includes a hole portion 141 in the center thereof and an annular protruding portion 142 around the hole portion 141 with the center axis Jl as the center. Through the hole portion 141, the shaft 31 shown in Fig. 1 is inserted. The annular protruding portion 142 protrudes downward. An inside portion of the annular protruding portion 142 functions as the bearing holding portion 143 for holding the ball bearing 42 of the bearing mechanism 4 shown in Fig. 1.

Fig. 6 is a plan view illustrating the armature 2 and the bus bars 24a, 24b, and 24c. Fig. 7 is a view showing the annular core 21 of the armature 2. Fig. 8 is a view showing a condition where two kinds of insulators 22a and 22b are attached to the core 21 (the reference numeral 22 in Fig. 1 indicates these insulators without distinction) . The core 21 includes a plurality of teeth 211 (nine teeth in the present embodiment) which are disposed radially around the rotor portion 3 (see Fig. 1) with the center axis Jl as the center as shown in Fig. 7. The core 21 also includes a plurality of core back elements 212 each having a substantially arc shape. The plurality of core back elements 212 are connected to the plurality of teeth 211, respectively, on the side opposite to the center axis Jl . A pair of the tooth 211 and the core back element 212 constitutes a split core 21a. A plurality of split cores 21a are annularly arranged, so that ends of the teeth 211 are directed to the rotor portion 3 in Fig. 1, and the core back elements 212 constitute a substantially annular core back 210 for magnetically coupling outer sides of the plurality of teeth 211. As shown in Fig. 8, part of the tooth 211 and the core back element 212 in each split core 21a is covered with the first insulator 22a or the second insulator 22b.

Figs. 9 and 10 are perspective views showing the two kinds of insulator components 220a and 220b. The first insulator 22a is a combination of the insulator component 220a with the insulator component 220b in which the insulator component 220b is upside down, and placed under the insulator component 220a. The second insulator 22b is a combination of two insulator components 220b in which one of the insulator component 220b is upside down.

As shown in Fig.8, among the nine insulators which respectively cover the nine teeth 211, four insulators are the first insulators 22a, and the remaining five insulators are the second insulators 22b. The insulator component 220a has three projections 225 which project upward (i.e., on the side of the resin plate 11 in Fig. 1) , as shown in Fig. 9. The insulator component 220b has the same configuration as that of the insulator component 220a except for the provision of the projections 225.

Fig. 11 is a sectional view of the split core 21a of which most of the upper surface, the lower surface, and the side face are covered with the insulator component 220a and the insulator component 220b. In the second insulator 22b, most of the upper surface, the lower surface, and the side face thereof are covered with the two insulator components 220b. As shown in Figs. 9 to 11, each of the insulator component 220a and the insulator component 220b includes an inner-wall portion 222 and an outer-wall portion 223. The inner-wall portion 222 protrudes in substantially parallel to the center axis Jl shown in Fig. 8 from an end of the tooth 211. The outer-wall portion 223 protrudes in substantially parallel to the center axis Jl on the side of the core back element 212 of the tooth 211. The inner-wall portion 222 has a substantially cylindrical surface with the center axis Jl as the center. The outer-wall portion 223 has a plate-like shape substantially parallel to the center axis Jl. Between the inner-wall portion 222 and the outer-wall portion 223, a bottom portion 224 for covering the upper surface or the lower surface of the tooth 211, and a side portion 226 for covering the side face of the tooth 211 are provided. Two grooves 211 are arranged in substantially parallel on the outside of the outer-wall portion 223. In Figs. 9 and 10, one of the two grooves 211 hides behind the outer-wall portion 223.

As shown in Figs. 9 and 11, the projections 225 are arranged in parallel to the grooves 221 on the outside of the grooves 221. As shown in Fig. 8, when the insulators 22a and 22b are radially arranged, the two grooves 221 extend substantially perpendicular to the radial direction (i.e. , in the substantially circumferential direction) along the upper surface of the core back elements 212 which are annularly arranged, and the two grooves 221 are arranged in the radial direction. As described above, all of the insulators 22a and 22b have the two grooves 221 which are substantially perpendicular to the radial direction, and many insulators have a common shape, so that the production cost of the motor 1 can be reduced. As shown in Fig. 11 by chain double-dashed line, a conducting wire which constitutes the coil 23 is wound on the insulators 22a and 22b between the inner-wall portion 222 and the outer-wall portion 223, and the two grooves 221 are positioned on the outside of the plurality of coils 23.

Fig. 12 is a view showing the arrangement of the bus bars 24a, 24b, and 24c (designated by the reference numeral 24 in Fig. 1) as the three wiring members. In Fig. 12, the contours of the core 21 and the connector portion 12 are depicted by chain double-dashed line. The bus bars 24a, 24b, and 24c are bus bars for U-phase, V-phase, and W-phase, respectively. Fig. 13 is a perspective view showing the U-phase bus bar 24a. One end of the bus bar 24a has an external connection terminal 241 as a driving connecting portion which is connected to an external power source, and the other end thereof has an internal connection terminal 242 as an internal connecting portion for supplying a current to the armature 2 (see Fig. 12) . The external connection terminal 241 extending in substantially parallel to the resin plate 11 (see Fig. 1) is supported by a flat terminal supporting portion 243, and the terminal supporting portion 243 and the internal connection terminal 242 are connected by an arm portion 245 which is bent as a bent line. The terminal supporting portion 243 has a hole portion 244, and the terminal supporting portion 243 is wider than the external connection terminal 241. Accordingly, any increase in electrical resistance of the terminal supporting portion 243 due to the provision of the hole portion 244 can be prevented. The other bus bars 24b and 24c have the same fundamental configuration as that of the bus bar 24a.

As shown in Fig. 6, the external connection terminal 241 of the ϋ-phase bus bar 24a is placed on the uppermost one of the first insulators 22a (the insulator component 220a) . As for the external connection terminal 241 of the bus bar 24a, one of the projections 225 of the insulator component 220a shown in Fig. 9 is inserted into the hole portion 244, and the projection 225 is fixed by thermal welding. The arm portion 245 of the bus bar 24a is held by the outer one of the two grooves 221 of the clockwise adjacent second insulator 22b (the insulator component 220b) , and then held by the inner one of the two grooves 221 of the next first insulator 22a. In the third second insulator 22b in the circumferential direction from the position of the external connection terminal 241, a portion in the vicinity of the internal connection terminal 242 is held by the inner one of the grooves 221.

The external connection terminal 241 of the V-phase bus bar 24b is placed on the first insulator 22a on which the external connection terminal 241 of the bus bar 24a is also placed. Similarly to the bus bar 24a, the external connection terminal 241 of the bus bar 24b is fixed to the center projection 225 by thermal welding. The arm portion 245 of the bus bar 24b extends to the second insulator 22b which is adjacent in the clockwise direction, and a portion in the vicinity of the internal connection terminal 242 is held by the inner one of the grooves 221 of the second insulator 22b. The external connection terminal 241 of the W-phase bus bar 24c is placed on the first insulator 22a on which the bus bars 24a and 24b are also placed. One of the projections 225 is inserted into the hole portion 244 of the bus bar 24c, and fixed by thermal welding. The arm portion 245 of the bus bar 24c extends in a symmetric manner to that of the bus bar 24a. The internal connection terminal 242 of the bus bar 24c is placed on the third insulator 22b in a counterclockwise direction from the .insulator 22a on which the external connection terminal 241 is placed.

As described above, the bus bars 24a to 24c are placed on the plurality of insulators 22a and 22b on the outside of the plurality of coils 23, and are held by utilizing the two grooves 221 arranged in the radial direction in the respective insulators . Among the three bus bars 24a to 24c, the bus bar 24c extends in the circumferentially counterclockwise direction from the connector portion 12 as the external connecting portion disposed on the outside of the outer peripheral portion of the armature 2. The bus bars 24a and 24b are arranged in parallel in the radial direction and extend in the circumferentially clockwise direction from the connector portion 12. In addition, the bus bar 24c is disposed in such a manner that it does not overlap any one of the bus bars 24a and 24b, and the number of bus bars, arranged in parallel in the radial direction is two at the maximum. As a result, the external diameter of the armature 2 can be reduced, so that the miniaturization of the motor 1 can be realized. In addition, by holding the bas bars by utilizing the grooves 221 of the insulators, the armature 2 can be further miniaturized. It is noted that a dedicated member for supporting the bus bars is not required, and the bus bars do not overlap in the axial direction, so that the height of the motor 1 can be reduced.

As shown in Fig. 6, the number of teeth 21 and the number of coils 23 are nine, respectively, in the armature 2. In each of three coil groups in which three teeth 21 are successively arranged, one conducting wire is wound around the three teeth 21 while the winding direction is inverted (for example, when viewed outward from the center axis Jl in the radial direction, the conducting wire is wound in the clockwise direction, in the counterclockwise direction, and then in the clockwise direction in the order from the first coil 23) . In this way, three coil groups corresponding to the U phase, V phase and W phase can be produced. In the armature 2, ends of the conducting wire of a coil group are connected to the internal connection terminals 242 of two bus bars for different phases, so that the three coil groups are connected by so-called delta connection. In other words, ends of the conducting wires of the adjacent coil groups are placed in an overlap manner in a position of the internal connection terminal 242 of one bus bar, and three coils 23 are successively connected between the respective internal connection terminals 242. Accordingly, the internal connection terminals 242 of the respective bus bars and the coils 23 can be easily connected.

Fig.14 is an enlarged view in the vicinity of the rotor portion 3. The rotor portion 3 includes a substantially columnar shaft 31 supported by the bearing mechanism 4, a rotor core 32 fixed to the shaft 31, a field magnet 33 attached to an outer circumferential surface of the rotor core 32, a substantially annular sensor magnet 34 attached to an upper portion of the rotor core 32, and a substantially cylindrical magnet cover 35 for covering the field magnet 33 and the sensor magnet 34. The rotor portion 3 rotates with the center axis Jl as the center, due to the torque generated between the armature 2 (see Fig. 1) and the field magnet 33. In Fig. 14, the right and left sections of the rotor portion 3 are taken in different positions. The field magnet 33 is a collectivity of a plurality of substantially plate-shaped field magnet elements (so-called segment magnets) substantially parallel to the center axis Jl, respectively, and the field magnet 33 is arranged on an outer circumferential surface of the rotor core 32 along the circumferential direction. The number of magnetic poles of the rotor portion 3 is eight. As the field magnet elements, a sintered body containing Neodymium may be used, for example.

Fig. 15 is a perspective view in which the lower surface of the rotor core 32 in Fig. 14 is directed upward. The rotor core 32 is formed by laminating a plurality of plate-shaped members in the direction of the center axis Jl. As shown in Figs. 14 and 15, the rotor core 32 includes a magnet holding portion 321 as an outer circumferential portion, a shaft fixing portion 322 as a center portion, and a coupling portion 324 for coupling the magnet holding portion 321 and the shaft fixing portion 322. The magnet holding portion 321 has a substantially cylindrical shape with the center axis Jl as the center, and the shaft fixing portion 322 also has a substantially cylindrical shape with the center axis Jl as the center. The coupling portion 324 functions as a rib for connecting an outer side face of the shaft fixing portion 322 and an inner side face of the magnet holding portion 321. Between the adjacent coupling portions 324, there is a through hole 323 parallel to the direction of the center axis Jl. In other words, four portions between the plurality of through holes 323 function as the coupling portions 324. As shown in Fig. 14, the magnet holding portion 321 holds the field magnet 33 on the outer side face thereof. Into the shaft fixing portion 322, the shaft 31 is inserted and fixed. One end (an upper end) of the shaft 31 protrudes from the upper cover 14.

As shown in Fig.15, the magnet holding portion 321 has an outer periphery of regular octagon and corner portions projecting radially outward, and extends in a rib-like manner in a direction substantially parallel to the center axis Jl. The corner portions abut against both sides of the field magnet 33, so that the movement of the field magnet 33 in the circumferential direction can be prevented. The inner circumference of the magnet holding portion 321 is a substantially cylindrical face, and a concave portion 325 is formed in the center of the lower portion of the rotor core 32 in Fig. 14 (the upper portion in Fig. 15) . As shown on the right side of the center axis Jl in Fig. 14, the height of the coupling portion 324 in the direction of the center axis Jl is smaller than the height of the magnet holding portion 321 in the direction of the center axis Jl .

As shown in Fig. 15, a portion of the magnet holding portion 321 in the vicinity of the coupling portion 324 protrudes as a convex portion 3231 on the inside of the concave portion 325. In other words, a portion of the coupling portion 324 in the vicinity of the magnet holding portion 321 is radially continuous to the magnet holding portion 321 entirely in the direction along the center axis Jl. Accordingly, the radial width of the magnet holding portion 321 is larger in the vicinity of the convex portion 3231, so as to ensure the thickness for a punch for caulking and fixing the plurality of plate-shaped members. As a result, the radial width of the magnet holding portion 321 is reduced, and the plurality of plate-shaped members can be joined by caulking in the position in the vicinity of the convex portion 3231.

Fig. 16 is a perspective view in which the lower side of the sensor magnet 34 in Fig. 14 is directed upward. The sensor magnet 34 includes an annular portion 341 opposite to a sensor 52 shown in Fig. 14, and a plurality of locking portions 342 protruding downward (upward in Fig. 16) from an inner peripheral portion of the annular portion 341. The upper surface in Fig. 14 includes a plurality of magnetic poles, thereby being an annular pole face opposite to the sensor 52. The plurality of locking portion 342 are respectively inserted into the through holes 323 of the rotor core 32 shown in Fig 14 (on the left side of the center axis JΪ) and in Fig. 15. The locking portions 342 constitute a circular-arc convex portion in the through holes 323 which continuously exists entirely in the circumferential direction with the center axis Jl as the center.

By means of the coupling portions 324, the locking portions 342 are locked with respect to the circumferential direction, so that the position of the sensor magnet 34 is prevented from being deviated in the circumferential direction during the rotation. Since the locking portions 342 of the sensor magnet 34 are continuous entirely in the circumferential direction in the through holes 323, the strength of the locking portions 342 can be improved as compared with the case where projections are provided only on both ends in the circumferential direction. In addition, since the locking portions 342 are engaged with all of the through holes 323, respectively, the reliability of the locking property for the sensor magnet 34 can be improved. The locking portions 342 of the sensor magnet 34 are locked by the through holes 323 of the rotor core 32, so as to realize the reduction in weight of the rotor core 32 and the rotation locking property for the sensor magnet 34 in the circumferential direction in the rotor portion 3. The provision of the plurality of through holes 323 and the concave portion 325 in the rotor core 32 can further reduce the weight of the rotor core 32, so that the moment of inertia can be reduced, and the response property of the motor 1 can be improved. Accordingly, a time lag from the open/close instruction of the slide door of a vehicle can be suppressed.

As shown in Fig. 14, the magnet cover 35 as a cover member for covering the field magnet 33 and the sensor magnet 34 is made from a nonmagnetic stainless steel. The magnet cover 35 covers an outer peripheral portion of the upper surface of the sensor magnet 34, the outer side face of the sensor magnet 34, the outer side face of the field magnet 33, and the lower surface of the field magnet 33. The magnet cover 35 is constituted by an upper cover 35a and a lower cover 35b. The upper cover 35a has a substantially annular upper portion and a substantially cylindrical side portion extending downward from an outer edge of the upper portion. The lower cover 35b has a substantially annular lower portion, and a substantially cylindrical side portion extending upward from an outer edge of the lower portion. The upper cover 35a is press fit to the assembly of the rotor core 32, the field magnet 33, and the sensor magnet 34 from the above. The lower cover 35b is press fit from the bottom and fixed. Accordingly, the axial and radial separations of the field magnet 33 and the sensor magnet 34 from the rotor core 32 can be easily prevented.

In the motor 1, as shown in Fig. 14, in order to reduce the axial height of the motor 1 and realize a thin body, the upper portion of the bearing holding portion 1313 of the stator cover 13 is positioned in the concave portion 325 of the rotor core 32. On the other hand, the lower portion of the bearing holding portion 143 of the upper cover 14 is positioned on the inside of the sensor magnet 34 of the rotor portion 3. Accordingly, the axial height of the motor

I can be further reduced. That is, the upper portion of the bearing holding portion 1313 radially overlaps the outer circumferential portion of the rotor core 32, and the lower portion of the bearing holding portion 143 radially overlaps the sensor magnet 34, so as to reduce the thickness of the motor 1. In addition, the stator cover 13 and the upper cover 14 can be produced by press working of a thin plate member, so that the thickness of the motor 1 can be reduced

(as compared with the case where the covers are produced by aluminum die casting, or the like, for example) .

Fig. 17 is a perspective view showing the resin plate 11 positioned between the armature 2 and the upper cover 14 in Fig. 1. Fig. 18 is a bottom view of the resin plate 11. The resin plate

II includes a circular-disk portion 111, a welding portion 112, a leg portion 113, and a terminal locating portion 114. The circular-disk portion 111 has an opening portion 1111 through which the shaft 31 shown in Fig. 1 is inserted in substantially the center thereof. The welding portion 112 is formed so as to have a substantially circular-arc shape, and the welding portions 112 are disposed in three positions of an outer edge of the circular-disk portion 111. The leg portions 113 are disposed in three positions of the outer edge of the circular-disk portion 111. The terminal locating portion 114 is formed so as to have a substantially flat plate shape, and protrudes outward from the cover portion 10 (see Fig. 1) in a continuous manner from the circular-disk portion 111.

As shown in Fig. 17, the welding portion 112 has a side portion extending downward from the outer edge of the circular-disk portion 111 and a welding flat plate portion 1123 of a substantially circular-arc shape extending radially outward from the lower end of the side portion. As shown in Figs. 17 and 18, the welding flat plate portion 1123 has three hole portions 1121 as through holes arranged in the circumferential direction.. On an outer edge of the welding flat plate portion 1123, a leg portion 1122 protruding downward is formed.

The insulator component 220a as the upper portion of the first insulator 22a can be joined with the resin plate 11 via the welding portion 112. Specifically, the projection 225 of the insulator component 220a is inserted into the hole portion 1121, and the projection 225 of the insulator component 220a is molten and welded to the welding portion 112, so that the resin plate 11 is easily joined to the first insulator 22a. Since the bus bars 24a to 24c are surely fixed to the grooves 221 of the insulators 22a and 22b, the width radially occupied by the bus bars 24a to 24c can be reduced. As a result, the resin plate 11 can be easily joined to the first insulator 22a on the outside of the bus bar 24, and the armature 2 and the bus bar 24 can be easily insulated from the surrounding members, in addition, due to the joining of the resin plate 11 to the first insulator 22a by thermal welding, the resin plate 11 can be easily and surely fixed onto the armature 2 with high reliability.

As described above, the projection 225 on the insulator component 220a of the first insulator 22a is also utilized for the joining to the bus bars 24a to 24c by thermal welding (see Fig. 6) , and the kinds of the insulator 22 are limited to the two kinds, i.e. , the first insulator 22a which can be joined to the resin plate 11 and the second insulator 22b (whereby the kinds of the insulator components are also limited to two kinds) , so that the production cost of the motor 1 can be reduced.

The leg portion 1122 of the welding portion 112 is engaged with the outer peripheral portion of the core back element 212 in the position of the cut-out 2121 disposed in the core back element 212 of the armature 2, and sandwiched between the side-wall portion 132 of the stator cover 13 and the core back element 212. The other leg portion 113 is engaged with the outer peripheral portion of the core back element 212 similarly to the leg portion 1122, and sandwiched between the side-wall portion 132 and the core back element 212. Accordingly, the height of the circular-disk portion 111 from the armature 2 is fixed, and the resin plate 11 is positioned in the circumferential direction by means of the cut-out 2121. In the resin plate 11, the leg portion 1122 is disposed in the welding portion 1122 fixed on the armature 2, so that the structure of the resin plate 11 can be simplified as compared with the case where all of the leg portions are disposed independently from the welding portion 112. An upper surface of the resin plate 11 is an even and flat plane, and a lower surface of the resin plate 11 includes a thick area 115 shown in Fig.18, and a thin area 116 which is farther fromthe armature 2 (see Fig. 1) with respect to the center axis Jl than the thick area 115. In Fig.18 , the thin area 116 is indicatedby hatched lines, and the outline of the circuit board 51 is indicated by chain double-dashed line. On the lower surface of the resin plate 11, a board locating area 1161 in which the circuit board 51 is located exists over the circular-disk portion 111 and the terminal locating portion 114. A plurality of projections 1162 formed on the board locating area 1161 are inserted into through holes of the circuit board 51, and then the circuit board 51 is fixed to the board locating area 1161 by thermal welding.

The whole of the board locating area 1161 is included in the thin area 116, so that the axial thickness of a portion in which the circuit board 51 overlaps the resin plate 11 can be reduced, thereby reducing the thickness of the motor 1. The lower-left and lower-right leg portions 113 in Fig. 18 which overlap the internal connection terminals 242 of the bus bars 24a and 24b connected to the armature 2 are included in the thin area 116, thereby reducing the thickness of the motor 1. As described above, in the resin plate 11, only a required portion is made to be the thin area 116, and the other portion is made to be the thick area 115, so that the strength of the resin plate 11 is ensured.

Fig. 19 is a view showing a section of the terminal locating portion 114 in the position indicated by arrow C in Fig. 18. On a lower surface of the circuit board 51 in Fig. 19 (a surface on the side of the armature 2 in Fig. 1) , a connector 511 as a signal connecting portion for outputting a signal from the sensor 52 to the external is attached. Joint terminals 5111 of the connector 511 pass through the circuit board 51, and are joined to the circuit board 51 on the side of the resin plate 11 by soldering or other means .

The connector portion 12 is constituted by the external connection terminals 241 of the three bus bars 24a to 24c, and a portion in the vicinity of the terminal locating portion 114 of the resin plate 11 and the connector 511 of the circuit board 51. As shown in Fig.1, the connector portion 12 is positioned on the outside of the stator cover 13. As indicated by chain double-dashed line in Fig. 19, the lower side of the terminal locating portion 114 is covered with a substantially tray-like connector cover 121 having a flat bottom portion and a side-wall portion. By the provision of the connector cover 121, the cut-out 1321 of the stator cover 13 is closed, so that invasion of foreign matters into the motor 1 can be prevented.

As shown in Fig. 17, the terminal locating portion 114 has a concave portion 1141 which is concave when viewed from the side of the circuit board 51, but which is convex when viewed from the other side. As shown in Fig. 19, the joining portion of the connector 511 is covered with the concave portion 1141. The terminal locating portion 114 protrudes to the outside from the cover portion 10 (see Fig.1) , and the upper cover 14 does not exist on the terminal locating portion 114, so that the concave portion 1141 can be formed in the resin plate 11 without considering the thickness of the upper cover 14. Thus, the thickness of the motor 1 can be reduced. As shown in Figs. 18 and 19, in the terminal locating portion 114, an outer peripheral rib 1142 protruding downward (i.e., to the side of the external connection terminal 241) from the outer peripheral portion is formed. With such a configuration, the strength of the portion on the outer side of the cover portion 10 included in the thin area 116 of the resin plate 11 is increased. In addition, the terminal locating portion 114 includes two isolating ribs 1143 protruding between the respective two of the three external connection terminals 241 on the lower surface thereof (i.e., on the surface on the side of the armature 2) . With such a configuration, any contact of the respective external connection terminals 241 can be prevented.

In the connector portion 12, since the connector 511 of the circuit board 51 is adjacent to the external connection terminals 241 of the bus bars 24a to 24c, it is possible to omit a process of changing the direction of the motor 1 for a worker when the connecting work for the connector 511 and the external connection terminals 241 is to be performed, so that the connecting work of various external wirings to the motor 1 can be easily performed. In addition, the connector portion 12 is positioned on the outside of the cover portion 10, so that various wirings to the motor 1 can be easily performed after the assembling of the motor 1.

The embodiments of the present invention are described above, but the present invention is not limited to the above-described embodiments. In addition, various modifications can be performed in the above-described embodiments.

For example, the locking portion 342 of the sensor magnet 34 in Fig. 16 does not necessarily have a circular-arc shape, but may have a linear shape (i.e. , a flat-plate shape) . The locking portions 342 of the sensor magnet 34 may be engaged with only some of the through holes 323. The core 21 shown in Fig. 7 is not limited to the collectivity of the split cores 21a in which teeth 211 are independently formed. For example, the core 21 may be a collectivity of split cores in which three teeth 211 constitute one group. Alternatively, the core 21 may be an entirely integrated one core 21.

As for the projections 1322 of the stator cover 13 in Fig. 3, any number of projections 1322 maybe formed at substantially regular pitches in the circumferential direction, as far as the number is three or more. The shapes of the bearing holding portions 1313 and 143 are not limited to those described in the embodiments . The whole of the bearing holding portions 1313 and 143 may be positioned in the concave portion 325 of the rotor core 32 or on the inside of the sensor magnet 34. In addition, as the bearing mechanism 4, other types than the ball bearings 41 and 42 may be adopted. In the cover portion 10, the upper cover 14 may cover the outer side face of the armature 2, and a plate-shaped lower cover may be disposed instead of the stator cover 13.

In the case where the radial width of the magnet holding portion 321 is sufficiently ensured, the height of the coupling portion 342 of the rotor core 32 in the direction of the center axis Jl may be smaller than the height of the magnet holding portion 321 as the outer circumferential portion over the entire of the coupling portion 342.

The magnet cover 35 shown in Fig.14 does not necessarily cover all of the outer side face, the upper surface, and the lower surface of the rotor portion 3, but may cover at least the outer circumferential portion of the pole face of the sensor magnet 34 and a portion of the field magnet 33 on the side of the sensor magnet 34. With such a configuration, these magnets can be collectively held efficiently. In addition, the outer side face of the sensor magnet 34 may function as the pole face. In such a case, the sensor 52 is disposed opposite to the outer side face of the sensor magnet 34.

The insulators 22a and 22b shown in Figs. 6 and 8 are not necessarily provided for teeth 211 individually, but an integrated insulator for a plurality of teeth 211 may be provided. The number of projections 225 formed in the first insulator 22a may be four or more. The hole portion 1121 formed in the welding portion 112 of the resin plate 11 may be a cut-out through which the projection 225 on the insulator component 220a (see Fig. 9) can be inserted and fixed by thermal welding.

The connector portion 12 as the external connecting portion is positioned on the outside of the outer peripheral portion of the armature 2, but may be positioned on the outer peripheral portion of the armature 2. In addition, for the external connection terminals 241 and the connector 511, various shapes and structures may be adopted.

The application of the motor 1 is not limited to the driving source for the electrically-operated slide door of the vehicle, but the motor 1 may be used as a driving source for a power window or an electrically-operated roof. In addition, the motor 1 may be used for various applications other than the vehicle.

The scope of the present invention is to be determined solely by the following claims .

Claims

1. A motor of electric type comprising: an annual armature; a rotor portion inserted into the armature; a bearing mechanism for supporting the rotor portion with respect to the armature in a rotatable manner with a center axis of the armature as the center; and a wiring portion, disposed on the armature, functioning as a supply path of a driving current to the armature, wherein the armature includes : a core having a plurality of teeth radially disposed around the rotor portion and a core back for magnetically coupling the outsides of the plurality of teeth; a plurality of insulators for covering the plurality of teeth, respectively; and a plurality of coils formed by winding a conducting wire on the plurality of insulators, and the wiring portion has three wiring members disposed on the plurality of insulators on the outside of the plurality of coils, one wiringmember of the three wiringmembers extends in one direction of the circumferential direction from an external connecting portion disposed in an outer peripheral portion of the armature or on the outside of the peripheral portion of the armature, the other two wiring members of the three wiring members are radially arranged and extend in a direction opposite to the one direction of the circumferential direction from the external connecting portion, and the one wiring member does not overlap the two wiring members in the radial direction.

2. A motor according to claim 1, wherein the plurality of insulators extend in a substantially circumferential direction on the outside of the plurality of coils, and have grooves for holding the three wiring members.

3. A motor according to claim 2, wherein each of the plurality of insulators has two grooves which are radially arranged and utilized for holding the wiring members

4. A motor according to claim 3, wherein the plurality of coils are connected by delta connection.

5. A motor according,to claim 4, wherein the number of the plurality of teeth is nine, and in each of three groups of coils in which three teeth are successively arranged, one conducting wire is wound around the three teeth while inverting the winding direction, thereby forming three coils, and both ends of the three groups of coils are connected, thereby connecting the three groups of coils by delta connection. β. A motor according to claim 5, further comprising a substantially plate-shaped resin plate which covers the wiring portion, wherein the resin plate is joined to the plurality of insulators on the outside of the three wiring members.

7. A motor according to claim 6, wherein the plurality of insulators are only two kinds of insulators including a first insulator which can be joined to the resin plate, and a second insulator.

8. A motor according to claim 7 , wherein the first insulator has projections protruding on the side of the resin plate, and the projections and the resin plate are joined by thermal welding.

9. A motor according to claim 8, wherein the first insulator has three or more projections protruding on the side of the resin plate, and the three or more projections of any one of the first insulators are joined to the three wiring members by thermal welding.

10. A motor according to claim 9, wherein the motor is installed in a gap between an inner wall and an outer wall of a vehicle.

11. A motor of electric type comprising: an annular armature; a rotor portion inserted into the armature; a bearing mechanism for supporting the rotor portion with respect to the armature in a rotatable manner with a center axis of the armature as the center; a wiring portion, disposed on the armature, functioning as a supply path of a driving current to the armature; and a plate-shaped resin plate for covering the wiring portion, wherein the armature includes: a core having a plurality of teeth radially disposed around the rotor portion and a core back for magnetically coupling the outsides of the plurality of teeth; a plurality of insulators for covering the plurality of teeth, respectively; and a plurality of coils formed by winding a conducting wire on the plurality of insulators, the wiring portion has three wiring members disposed on the plurality of insulators on the outside of the plurality of coils, one wiringmember of the three wiringmembers extends in one direction of the circumferential direction from an external connecting portion disposed in an outer peripheral portion of the armature or on the outside of the peripheral portion of the armature, the other two wiring members of the three wiring members are radially arranged and extend in a direction opposite to the one direction of the circumferential direction from the external connecting portion, and the one wiring member does not overlap the two wiring members in the radial direction, and the resin plate is joined to the plurality of insulators on the outside of the three wiring members.

12. A motor according to claim 11, wherein the plurality of insulators are only two kinds of insulators including a first insulator which can be joined to the resin plate and a second insulator.

13. A motor according to claim 12, wherein the first insulator has a projection protruding to the side of the resin plate, and the projection and the resin plate are joined by thermal welding.

14. A motor according to claim 13, wherein the first insulator has three or more projections protruding on the side of the resin plate, and the three or more projections of any one of the first insulators are joined to the three wiring members by thermal welding.

15. A motor according to claim 14, wherein the plurality of insulators extend in a substantially circumferential direction on the outside of the plurality of coils, and have grooves for holding the three wiring members.

16. A motor according to claim 15, wherein each of the plurality of insulators has two grooves which are radially arranged and utilized for holding the wiring members.

17. A motor according to claim 16, wherein the plurality of coils are connected by delta connection.