JP2009095139A - Electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To thin an electric motor with respect to an axial direction. <P>SOLUTION: The electric inner rotor-type electric motor includes a circular armature, a rotor part 3 having a field magnet 33, a bearing mechanism 4 which rotatably supports the rotor part 3 with a center axis J1 as a center against the armature and a cover part storing the armature. The cover part is constituted of a stator cover 13 covering an outer peripheral face and a lower part of the armature and an upper cover 14 covering an upper part. A recess 325 is arranged on a lower face side of the rotor core 32 in the rotor part 3. An upper part of a bearing holding part 1313, which the stator cover 13 formed by press working has, is positioned inside the recess 325. A circular sensor magnet 34 is fitted to an upper face of the rotor part 3; and a lower part of a bearing holding part 143, which the upper cover 14 formed of press processing has, is positioned in the sensor magnet 34. Thus, the motor can be thinned with respect to the axial direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electric motor.

  Various techniques for reducing the size of an inner rotor type electric motor in which a rotor portion having a permanent magnet is disposed inside a ring-shaped armature and rotates have been proposed. In particular, a motor that is assumed to be disposed in a narrow space, such as a motor mounted on an electric slide door of an automobile, is required to be thin in the axial direction.

In Patent Document 1, the rotor hub has an extending portion extending radially outward from the central portion of the rotating shaft in order to prevent deterioration in characteristics due to a temperature rise of the magnet. An AC generator for a vehicle is disclosed in which a cylindrical portion that houses a magnet is provided at an outer edge portion of the existing portion, so that the inside of the rotor is a hollow portion that is a cooling ventilation portion. In this vehicle alternator, a part of the bearing portion is disposed inside the cavity portion of the rotor.
JP 2004-350427 A

  By the way, in a motor used for an electric slide door of an automobile, a space in which the motor is arranged is limited. Therefore, in order to improve design flexibility, further reduction in thickness, weight, and cost are required.

  The present invention has been made in view of the above problems, and has as its main object to make the motor thinner in the axial direction.

  The invention according to claim 1 is an electric motor, which is an annular armature, a rotor portion inserted into the armature, and the rotor portion with respect to the armature. A bearing mechanism that rotatably supports a shaft; and a lower cover that covers a lower surface of the armature and has a bearing holding portion that holds at least a part of the bearing mechanism, and the rotor portion includes the bearing mechanism A rotor core that is fixed to the shaft and has a recess in the center of the lower portion, and a field magnet attached to the outer periphery of the rotor core, and the lower cover is formed by press working A part or the whole of the bearing holding portion of the lower cover is located in the concave portion of the rotor portion.

  The invention according to claim 2 is the motor according to claim 1, wherein the lower cover has a substantially bottomed cylindrical shape having a side wall portion covering at least a lower portion of the outer side surface of the armature, and the lower cover The side wall portion of the armature has a plurality of projecting portions that are formed by press working and project inward, and the lower surface of the core of the armature contacts the plurality of projecting portions.

  The invention according to claim 3 is the motor according to claim 1 or 2, wherein the upper cover has a bearing holding portion that covers the upper surface of the armature and holds a part of the bearing mechanism, and the rotor A sensor for detecting a rotational position of the part, wherein the rotor part is further provided with an annular sensor magnet attached to an upper part of the rotor core and having an annular magnetized surface facing the sensor. A part or the whole of the bearing holding part is located inside the sensor magnet of the rotor part.

  The invention according to claim 4 is an electric motor, which is an annular armature, a rotor portion inserted into the armature, and the rotor portion with respect to the armature. A bearing mechanism that rotatably supports an axis, an upper cover that covers the upper surface of the armature and has a bearing holding portion that holds at least a part of the bearing mechanism, and a sensor that detects the rotational position of the rotor portion The rotor part is attached to the upper part of the rotor core, a shaft supported by the bearing mechanism, a rotor core fixed to the shaft, a field magnet attached to the outer periphery of the rotor core, An annular sensor magnet having an annular magnetized surface facing the sensor, and a part or the whole of the bearing holding portion of the upper cover is positioned inside the sensor magnet of the rotor portion. That.

  The invention according to claim 5 is the motor according to claim 3 or 4, wherein the armature of the resin plate and the substantially plate-shaped resin plate positioned between the armature and the upper cover. A circuit board that is fixed to the side surface and to which the sensor is attached, and the resin plate has a thick area and a thin area that is farther from the armature than the thick area, A circuit board is attached to the thin region.

  The invention according to claim 6 is the motor according to claim 3 or 4, wherein the motor is disposed on the armature and a substantially plate-shaped resin plate positioned between the armature and the upper cover. And a wiring portion covered with the resin plate, wherein the resin plate is further away from the armature than the thick region. The thin-walled region overlaps with an internal connection portion connected to the armature of the wiring portion.

  The invention according to claim 7 is the motor according to any one of claims 1 to 6, and is mounted in a gap between the inner wall and the outer wall of the automobile.

  In the first, fourth, fifth and sixth aspects of the invention, the axial height of the motor can be kept low. Further, in the invention described in claim 2, the axial position of the electric element can be easily fixed, and in the invention described in claim 3, the height of the motor in the axial direction can be further reduced. .

  FIG. 1 is a longitudinal sectional view of an electric motor 1 (hereinafter referred to as “motor 1”) according to a first embodiment of the present invention, and also shows a part of the configuration on the back side from the cross section. The cross section is shown without parallel oblique lines. The motor 1 is a motor used as a drive source for an electric sliding door mounted on a vehicle, and is mounted in a gap between the inner wall and the outer wall of the vehicle, and has a height in the direction of the central axis J1 in order to secure a wide space in the vehicle. Has a thin structure that is smaller than the outer diameter. As shown in FIG. 1, the motor 1 is an inner rotor type motor, and has an annular armature 2 centered on the central axis J <b> 1, a substantially cylindrical rotor portion 3 inserted into the armature 2, and a shaft 31. A bearing mechanism 4 that supports the rotor unit 3 so as to be rotatable about the central axis J1 (also the central axis of the armature 2) with respect to the armature 2, a sensor unit 5 that detects the rotational position of the rotor unit 3, and an electric machine The cover part 10 which covers the child 2 and the substantially plate-shaped resin plate 11 located on the upper surface of the armature 2 are provided. Further, a part of the resin plate 11 protrudes to the outside of the cover part 10 and becomes a part of the connector part 12 having terminals for electrical connection with an external power source.

  The cover 10 is attached to the stator cover 13 that is a substantially bottomed cylindrical lower cover that covers the side surface and the lower surface of the armature 2 (that is, the surface opposite to the resin plate 11), and the stator cover 13. A substantially plate-like upper cover 14 covering the resin plate 11 is provided, and the armature 2 and the resin plate 11 are accommodated. In the following description, for convenience, the upper cover 14 side is described as the upper side and the stator cover 13 side is the lower side along the central axis J1, but the central axis J1 does not necessarily coincide with the direction of gravity.

  The armature 2 includes a core 21 formed by laminating a plurality of thin plate-shaped silicon steel plates, an insulator 22 covering the core 21, and a coil 23 wound from above the insulator 22. On the armature 2, a plurality of bus bars 24, which are wiring portions serving as a drive current supply path to the armature 2, are disposed, and the bus bars 24 are covered with the resin plate 11. The bearing mechanism 4 is a pair of ball bearings 41 and 42 arranged along the central axis J <b> 1, a bearing holding portion 1313 provided in the center of the stator cover 13, and a bearing provided in the center of the upper cover 14. It is held by the holding unit 143. The sensor unit 5 includes a circuit board 51 and a sensor 52 that is a magnetic field detection element such as a Hall element, and the sensor 52 detects a magnetic field opposite to the sensor magnet 34 attached to the rotor unit 3, whereby the rotor The rotational position of the part 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, and FIG. 3 is a longitudinal sectional view at a position indicated by an arrow A in FIG. As shown in FIGS. 2 and 3, the stator cover 13 includes a disk-shaped bottom 131, a cylindrical side wall 132 extending upward from the outer edge of the bottom 131, and the upper end of the side wall 132 perpendicular to the central axis J <b> 1. It has a flange portion 133 that spreads outward in the direction. The bottom 131 has a hole 1311 into which the shaft 31 of FIG. 1 is inserted in the center, and an annular protrusion 1312 that protrudes upward around the central axis J1 around the hole 1311. The inner portion is a bearing holding portion 1313 that holds the ball bearing 41 of the bearing mechanism 4 shown in FIG.

  As shown in FIG. 3, the resin plate 11 of FIG. 1 and a notch 1321 for allowing the bus bar 24 to pass through are formed in the side wall portion 132 that covers the outer surface of the armature 2 at a position where the connector portion 12 is disposed. Furthermore, a plurality of protrusions 1322 that slightly protrude inward are provided at four locations that are even in the circumferential direction. As shown in FIG. 1, the armature 2 is fixed to the stator cover 13 by press-fitting (adhesive may be used together if necessary), and the lower surface of the core 21 of the armature 2 is formed into a plurality of protrusions 1322. The armature 2 is positioned and supported by contact. Thereby, the position of the armature 2 in the axial direction can be easily fixed, and the propagation of the vibration of the armature 2 to the cover portion 10 is also realized.

  As shown in FIG. 2, the flange 133 has a shape in which three corners of a triangle are rounded, and has screw holes 1331 for fixing the upper cover 14 in FIG. 1 at the three corners. Further, a part of the flange portion 133 is cut out together with the notch 1321 of the side wall portion 132 at a position where the connector portion 12 is disposed. The stator cover 13 is formed at a low cost by pressing a thin plate-like member, and the axial height of the motor 1 is kept low by using a thin plate material. It is easily formed by breaking a part of 132 and bending it inward.

  4 is a plan view showing the upper cover 14 covering the upper surface of the armature 2, and FIG. 5 is a cross-sectional view of the upper cover 14 at a position indicated by an arrow B in FIG. The upper cover 14 has a substantially triangular shape that is the same as the flange portion 133 of the stator cover 13 of FIG. 2, and the hole portions 144 are formed at three locations corresponding to the screw holes 1331 of the stator cover 13. Further, the upper cover 14 has a hole portion 141 into which the shaft 31 of FIG. 1 is inserted in the center, and an annular convex portion 142 that protrudes downward around the central axis J1 around the hole portion 141. A portion inside the portion 142 is a bearing holding portion 143 that holds the ball bearing 42 of the bearing mechanism 4 shown in FIG.

  6 is a plan view showing 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, and FIG. 8 shows two types of insulators 22a and 22b in the core 21. Is a view showing a state in which is attached (reference numeral 22 in FIG. 1 shows these insulators without distinction). As shown in FIG. 7, the core 21 has a plurality (9 in this embodiment) of teeth 211 arranged radially around the rotor portion 3 (see FIG. 1) around the central axis J1, and the central axis A plurality of substantially arc-shaped core back elements 212 connected to the plurality of teeth 211 on the side opposite to J1 are provided. Each tooth 211 and one core back element 212 form a split core 21a, and a plurality of split cores 21a are arranged in an annular shape, whereby the tip of the tooth 211 is directed to the rotor portion 3 in FIG. The back element 212 forms an annular core back 210 that magnetically connects the outsides of the plurality of teeth 211. As shown in FIG. 8, the teeth 211 and the core back elements 212 of each divided core 21a are covered with the first insulator 22a or the second insulator 22b.

  FIG. 9 and FIG. 10 are perspective views showing two types of insulator parts 220a and 220b. The first insulator 22a is configured by reversing and combining the insulator parts 220b below the insulator parts 220a. 22b is comprised by combining two insulator components 220b up and down.

  As shown in FIG. 8, four of the nine insulators that respectively cover the nine teeth 211 are the first insulators 22a, and the remaining five are the second insulators 22b. As shown in FIG. 9, the insulator component 220 a has three protrusions 225 that protrude upward (that is, on the resin plate 11 side in FIG. 1), and the insulator component 220 b has the same structure as the insulator component 220 a except that the protrusion 225 does not exist. It is the same shape.

  FIG. 11 is a cross-sectional view showing the first insulator 22a, that is, the split core 21a in which most of the upper surface, the lower surface, and the side surfaces are covered by the insulator component 220a and the insulator component 220b. In the second insulator 22b, the upper surface, the lower surface, and the side surface are substantially covered with the two insulator parts 220b. As shown in FIGS. 9 to 11, the insulator component 220 a and the insulator component 220 b include an inner wall 222 that protrudes in parallel to the central axis J <b> 1 shown in FIG. 8 from the tip of the tooth 211, and the core 211 side of the tooth 211. The outer wall 223 protrudes parallel to the central axis J1, the inner wall 222 has a cylindrical surface centered on the central axis J1, and the outer wall 223 has a plate shape parallel to the central axis J1. ing. Between the inner wall portion 222 and the outer wall portion 223, a bottom portion 224 that covers the upper surface or the lower surface of the tooth 211 and a side portion 226 that covers the side surface of the tooth 211 are provided, and two grooves 221 are formed outside the outer wall portion 223. Provided in parallel. 9 and 10, one of the two grooves 221 is hidden behind the outer wall portion 223.

  As shown in FIGS. 9 and 11, the protrusions 225 are arranged in parallel to the grooves 221 on the outer side of the grooves 221, and the insulators 22a and 22b are radially arranged as shown in FIG. 221 extends in the radial direction (that is, substantially in the circumferential direction) along the upper surface of the core back elements 212 arranged in a ring shape, and is arranged in the radial direction. As described above, all the insulators 22a and 22b have the two grooves 221 perpendicular to the radial direction, and the manufacturing cost of the motor 1 is reduced by making the shape common to many insulators. In addition, as shown with a dashed-two dotted line in FIG. 11, the conducting wire which forms the coil 23 is wound between the inner wall part 222 and the outer wall part 223 on insulator 22a, 22b, and the position of two groove | channels 221 is The outside of the plurality of coils 23 is used.

  FIG. 12 is a diagram showing the arrangement of bus bars 24a, 24b, and 24c (indicated by reference numeral 24 in FIG. 1) that are three wiring members. The outlines of the core 21 and the connector portion 12 are indicated by two-dot chain lines. Show. 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 a U-phase bus bar 24a. One end of the bus bar 24a is an external connection terminal 241 that is a drive connection portion connected to an external power source, and the other end is an internal connection terminal 242 that is an internal connection portion that supplies current to the armature 2. (See FIG. 12). The external connection terminal 241 extending in parallel with the resin plate 11 (see FIG. 1) is supported by a flat terminal support portion 243, and the terminal support portion 243 and the internal connection terminal 242 are connected by an arm portion 245 bent in a broken line shape. Is done. The terminal support portion 243 is provided with a hole portion 244 and is wider than the external connection terminal 241, thereby preventing an increase in electrical resistance of the terminal support portion 243 due to the provision of the hole portion 244. The other bus bars 24b and 24c have the same basic structure as the bus bar 24a.

  As shown in FIG. 6, the external connection terminal 241 of the U-phase bus bar 24a is arranged on the first insulator 22a (insulator component 220a) positioned at the top in FIG. 6, and the insulator part 220a shown in FIG. One of the protrusions 225 is inserted into the hole 244 and fixed by heat welding in which the protrusion 225 is melted. The arm portion 245 of the bus bar 24a is held in the outer groove 221 of the two grooves 221 of the second insulator 22b (insulator component 220b) adjacent in the clockwise direction, and held in the inner groove 221 of the next first insulator 22a. In the third insulator 22b, which is third 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 in the inner groove 221.

  The external connection terminal 241 of the V-phase bus bar 24b is disposed on the same first insulator 22a as the external connection terminal 241 of the bus bar 24a, and is fixed to the central protrusion 225 by thermal welding in the same manner as the bus bar 24a. The arm portion 245 of the bus bar 24b extends to the second insulator 22b adjacent in the clockwise direction, and a portion in the vicinity of the internal connection terminal 242 is held in the groove 221 inside the second insulator 22b.

  The external connection terminal 241 of the W-phase bus bar 24c is disposed on the same first insulator 22a as the bus bars 24a and 24b, and one of the protrusions 225 is inserted into the hole 244 and fixed by thermal welding. The arm portion 245 of the bus bar 24c is symmetrical with the bus bar 24a, and the internal connection terminal 242 of the bus bar 24c is disposed on the third insulator 22b counterclockwise from the insulator 22a where the external connection terminal 241 is disposed. .

  As described above, the bus bars 24a to 24c are disposed on the plurality of insulators 22a and 22b outside the plurality of coils 23, and are held using the two grooves 221 arranged in the radial direction in each insulator. Of the three bus bars 24a to 24c, the bus bar 24c extends in the counterclockwise direction in the circumferential direction from the connector portion 12 which is an external connection portion provided outside the outer edge portion of the armature 2, and the bus bar 24a and the bus bar 24b are , Extending in the clockwise direction from the connector portion 12 while being aligned in the radial direction. Further, the bus bars 24c are arranged so as not to overlap with either the bus bar 24a or the bus bar 24b in the radial direction, and the number of bus bars arranged in the radial direction is 2 at the maximum. As a result, it is possible to reduce the outer diameter of the armature 2 and reduce the size of the motor 1. Further, the armature 2 can be further reduced in size by holding the bus bar using the groove 221 of the insulator. Of course, a dedicated member for supporting the bus bar is not necessary, and the bus bar does not overlap in the axial direction, so that the height of the motor 1 can be suppressed.

  As shown in FIG. 6, the number of the teeth 211 and the coils 23 in the armature 2 is 9, and each of the three sets of coil groups in which the three teeth 211 are continuously arranged is reversed while the winding direction is reversed. The three conductive wires are wound around three teeth 211 (for example, when viewed from the central axis J1 toward the radial outer side, clockwise, counterclockwise, and clockwise orientation from the first coil 23 in order) Wound around). Thereby, three coil groups corresponding to the U phase, the V phase, and the W phase are formed. In the armature 2, three sets of coil groups are connected by so-called delta connection by connecting both ends of the conductors of the coil groups to the internal connection terminals 242 of two bus bars of different phases. In other words, the ends of the conductors of adjacent coil groups are arranged so as to overlap the position of the internal connection terminal 242 of one bus bar, and the three coils 23 are connected continuously between the internal connection terminals 242. Thereby, the internal connection terminal 242 of each bus bar and the coil 23 can be easily connected.

  FIG. 14 is an enlarged view of the vicinity of the rotor unit 3. The rotor unit 3 includes a cylindrical shaft 31 supported by the bearing mechanism 4 (ball bearings 41 and 42), a rotor core 32 fixed to the shaft 31, and a rotor core 32. A field magnet 33 attached to the outer periphery, an annular sensor magnet 34 attached to the top of the rotor core 32, and a substantially cylindrical magnet cover 35 covering the field magnet 33 and the sensor magnet 34; By the torque generated between the armature 2 (see FIG. 1) and the field magnet 33, the armature 2 rotates around the central axis J1. In FIG. 14, the left and right sides of the rotor unit 3 are shown in cross sections at different positions. The field magnet 33 is a set of a plurality of substantially plate-like field magnet elements (so-called segment magnets) each parallel to the central axis J1, and is arranged on the outer peripheral surface of the rotor core 32 along the circumferential direction. The number of magnetic poles of the rotor part 3 is 8. As the field magnet element, for example, a sintered body containing neodymium is used.

  15 is a perspective view of the rotor core 32 with the lower surface in FIG. 14 facing upward. The rotor core 32 is formed by laminating a plurality of plate-like members in the direction of the central axis J1, and as shown in FIGS. 14 and 15, the rotor core 32 has a magnet holding portion 321 as an outer peripheral portion and a shaft fixed as a central portion. And a connecting portion 324 that connects the magnet holding portion 321 and the shaft fixing portion 322. The magnet holding portion 321 has a substantially cylindrical shape centered on the central axis J1, and the shaft fixing portion 322 also has a substantially cylindrical shape centered on the central axis J1. The connecting portion 324 has a rib shape that connects the outer surface of the shaft fixing portion 322 and the inner surface of the magnet holding portion 321, and a through hole 323 parallel to the central axis J <b> 1 direction is formed between the adjacent connecting portions 324. It is located at four places in the circumferential direction. In other words, four portions between the plurality of through holes 323 serve as the connecting portions 324. As shown in FIG. 14, the magnet holding portion 321 holds the field magnet 33 on the outer surface, the shaft 31 is inserted and fixed to the shaft fixing portion 322, and one end (upper end) of the shaft 31 is the upper cover 14. Protrude from.

  As shown in FIG. 15, the magnet holding portion 321 has a regular octagonal outer periphery, and the corner portion has a rib shape that protrudes radially outward and extends in a direction parallel to the central axis J1. The corner portions are in contact with both sides of the field magnet 33, thereby preventing the field magnet 33 from moving in the circumferential direction. The inner periphery of the magnet holding portion 321 has a cylindrical surface, and a recess 325 is formed at the center of the lower portion of the rotor core 32 in FIG. 14 (upper portion in FIG. 15), as shown on the right side of the central axis J1 in FIG. The height of the connecting portion 324 in the central axis J1 direction is smaller than the height of the magnet holding portion 321 in the central axis J1 direction.

  Further, as shown in FIG. 15, a portion in the vicinity of the connecting portion 324 of the magnet holding portion 321 protrudes as a convex portion 3231 inside the concave portion 325. In other words, the portion of the connecting portion 324 near the magnet holding portion 321 is continuous with the magnet holding portion 321 in the radial direction in the entire central axis J1 direction. As a result, the magnet holding portion 321 is increased in radial width in the vicinity of the convex portion 3231, and a thickness for a punch for caulking and fixing a plurality of plate-like members is secured. As a result, it is realized that the plurality of plate-like members are joined by caulking at positions near the convex portion 3231 while reducing the radial width of the magnet holding portion 321.

  FIG. 16 is a perspective view of the sensor magnet 34 with the lower side in FIG. 14 facing upward. The sensor magnet 34 has an annular portion 341 facing the sensor 52 shown in FIG. 14 and a plurality of locking portions 342 protruding downward (upward in FIG. 16) from the inner edge of the annular portion 341. The upper surface of is an annular magnetized surface facing the sensor 52 perpendicular to the central axis J1 magnetized by multipole. The plurality of locking portions 342 are respectively inserted into the through holes 323 of the rotor core 32 shown in FIG. 14 (on the left side of the central axis J1) and FIG. 15, and are continuous in the entire circumferential direction around the central axis J1 in the through holes 323. It is an arcuate convex portion that exists as a result.

  Since the locking portion 342 is locked in the circumferential direction by the connecting portion 324, the position of the sensor magnet 34 is prevented from shifting in the circumferential direction during rotation. Further, since the locking portion 342 of the sensor magnet 34 is continuous in the entire circumferential direction in the through hole 323, the strength of the locking portion 342 is improved as compared with the case where protrusions are provided only at both ends in the circumferential direction. can do. Further, the engaging portions 342 are fitted into all the through holes 323, whereby the reliability of the rotation prevention of the sensor magnet 34 can be improved. Further, by engaging the engaging portion 342 of the sensor magnet 34 in the through hole 323 of the rotor core 32, the rotor portion 3 can be reduced in weight and the circumferential direction of the sensor magnet 34 with a simple structure. A detent is realized. By forming the plurality of through holes 323 and the recesses 325 in the rotor core 32, the weight of the rotor core 32 can be further reduced, and the moment of inertia can be reduced to improve the response characteristics of the motor 1. Thereby, suppression of the time lag after the opening / closing instruction | indication of the sliding door of a motor vehicle is implemented is implement | achieved.

  As shown in FIG. 14, a magnet cover 35 that is a cover member that covers the field magnet 33 and the sensor magnet 34 is formed of nonmagnetic stainless steel. The outer surface of the magnet 34, the outer surface of the field magnet 33, and the lower surface of the field magnet 33 are covered. The magnet cover 35 includes an upper cover 35a and a lower cover 35b. The upper cover 35a has an annular upper portion and a cylindrical side portion extending downward from an outer edge of the upper portion, and the lower cover 35b is an annular lower portion. And a cylindrical side portion extending upward from the outer edge of the lower portion. The upper cover 35a is press-fitted into the assembly of the rotor core 32, the field magnet 33 and the sensor magnet 34 from above, and the lower cover 35b is press-fitted from below and fixed. Thereby, separation of the field magnet 33 and the sensor magnet 34 from the rotor core 32 in the axial direction and the radial direction can be easily prevented.

  In the motor 1, as shown in FIG. 14, 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 in order to reduce the height in the axial direction of the motor 1 and realize a reduction in thickness. To do. On the other hand, the lower part of the bearing holding part 143 of the upper cover 14 is also located inside the sensor magnet 34 of the rotor part 3, thereby realizing a further reduction in the axial height of the motor 1. That is, the motor 1 is thinned by the upper portion of the bearing holding portion 1313 and the outer peripheral portion of the rotor core 32 overlapping in the radial direction, and the lower portion of the bearing holding portion 143 and the sensor magnet 34 overlapping in the radial direction. Furthermore, the motor 1 is made thinner by forming the stator cover 13 and the upper cover 14 by press molding of a thin plate member (compared to a case where the stator cover 13 and the upper cover 14 are formed by aluminum die casting or the like).

  FIG. 17 is a perspective view showing the resin plate 11 positioned between the armature 2 and the upper cover 14 shown in FIG. 1, and FIG. 18 is a bottom view of the resin plate 11. The resin plate 11 includes a disc portion 111 having an opening 1111 into which the shaft 31 of FIG. 1 is inserted in the center, an arc-shaped weld portion 112 disposed at three locations on the outer edge of the disc portion 111, and the disc portion 111. Leg portions 113 arranged at three locations on the outer edge, and flat terminal arrangement portions 114 formed so as to be continuous from the disc portion 111 and projecting outside the cover portion 10 (see FIG. 1) are provided.

  As shown in FIG. 17, the welded portion 112 has a side portion extending downward from the outer edge of the disc portion 111 and a substantially arc-shaped welded flat plate portion 1123 extending radially outward from the lower end of the side portion. As shown in FIGS. 17 and 18, the welded flat plate portion 1123 is formed with three hole portions 1121 that are arranged in the circumferential direction, and the welded flat plate portion 1123 is provided with a leg portion 1122 that protrudes downward. .

  The insulator part 220a, which is the upper part of the first insulator 22a shown in FIG. 9, can be joined to the resin plate 11 via the welded part 112, and the protrusion 225 of the insulator part 220a is inserted into the hole part 1121, and the insulator part 220a. The protrusion 225 is melted and thermally welded to the welded portion 112, whereby the resin plate 11 is easily joined to the first insulator 22a. The bus bars 24a to 24c are securely fixed to the grooves 221 of the insulators 22a and 22b, so that the width occupied by the bus bars 24a to 24c in the radial direction can be reduced. As a result, the resin plate 11 is attached to the bus bar 24. It can be easily joined to the first insulator 22a on the outside, and the armature 2 and the bus bar 24 are easily insulated from surrounding members. Furthermore, the resin plate 11 is easily and reliably fixed on the armature 2 with high reliability by joining the resin plate 11 by heat welding with the first insulator 22a.

  As described above, the protrusion 225 on the insulator component 220a of the first insulator 22a is also used for joining to the bus bars 24a to 24c (see FIG. 6) by heat welding, and the type of the insulator 22 can be joined to the resin plate 11. The manufacturing cost of the motor 1 can be reduced by being limited to only two types of the first insulator 22a and the other second insulator 22b (there are also limited to two types of insulator parts). .

  The legs 1122 provided on the welded portion 112 engage with the outer edge of the core back element 212 at the position of the notch 2121 provided in the core back element 212 of the armature 2 shown in FIG. 6, and are shown in FIGS. 1 and 3. It is sandwiched between the side wall 132 of the stator cover 13 and the core back element 212. The other leg 113 is also engaged with the outer edge of the core back element 212 in the same manner as the leg 1122 and is sandwiched between the side wall 132 and the core back element 212, whereby the armature 2 of the disc part 111. The resin plate 11 is also positioned in the circumferential direction by the notch 2121. In the resin plate 11, the leg portion 1122 is provided in the welding portion 112 fixed on the armature 2, thereby simplifying the structure of the resin plate 11 than providing all the leg portions independently from the welding portion 112. The

  The upper surface of the resin plate 11 is a flat surface without unevenness, and the lower surface is a thick region 115 shown in FIG. 18 and a thin region farther from the armature 2 (see FIG. 1) than the thick region 115 in the direction of the central axis J1. In FIG. 18, parallel thin lines are given to the thin region 116 and the outer shape of the circuit board 51 is indicated by a two-dot chain line. In addition, on the lower surface of the resin plate 11 (that is, the surface on the armature 2 side), the circuit board arrangement area 1161 having the sensor 52 (see FIG. 14) is arranged (that is, overlaps with the circuit board 51). The circuit board 51 is placed on the board by thermal welding that exists across the plate part 111 and the terminal placement part 114 and is melted by inserting a plurality of protrusions 1162 formed on the board placement area 1161 into the through holes of the circuit board 51. The region 1161 is fixed.

  The entire board arrangement area 1161 is included in the thin area 116, whereby the axial thickness of the portion where the circuit board 51 and the resin plate 11 overlap can be reduced, and the motor 1 can be made thinner. In addition, the lower left and lower right leg portions 113 of FIG. 18, which overlap with the internal connection terminals 242 (see FIG. 12) of the bus bars 24 a and 24 b connected to the armature 2, are also included in the thin region 116. The motor 1 can be thinned. As described above, the strength of the resin plate 11 is ensured by forming only a necessary portion in the resin plate 11 as the thin region 116 and the other as the thick region 115.

  19 is a view showing a cross section of the terminal arrangement portion 114 at a position indicated by an arrow C in FIG. 18. The sensor 52 is provided on the lower surface (surface on the armature 2 side in FIG. 1) of the circuit board 51 in FIG. A connector 511 which is a signal connection portion for outputting a signal from (see FIG. 1) to the outside is attached, and the joining terminal 5111 of the connector 511 penetrates the circuit board 51 and the surface of the circuit board 51 on the resin plate 11 side. Are joined with solder or the like.

  The connector portion 12 is composed of the external connection terminals 241 of the three bus bars 24a to 24c in FIG. 19, the terminal arrangement portion 114 of the resin plate 11, and the portion in the vicinity of the connector 511 of the circuit board 51, as shown in FIG. In addition, the connector portion 12 is located outside the stator cover 13. As shown by a two-dot chain line in FIG. 19, the lower surface side of the terminal arrangement portion 114 is covered with a substantially tray-shaped connector cover 121 having a flat bottom portion and a side wall portion. 3, the notch 1321 of the stator cover 13 shown in FIG. 3 is closed to prevent foreign matter from entering the motor 1.

  As shown in FIG. 17, the terminal arrangement portion 114 is provided with a concave portion 1141 that is concave when viewed from the circuit board 51 side and is convex on the opposite side. As shown in FIG. The joint is covered. Since the terminal arrangement portion 114 protrudes from the cover portion 10 (see FIG. 1) and the upper cover 14 does not exist on the terminal arrangement portion 114, the terminal arrangement portion 114 is recessed in the resin plate 11 without considering the thickness of the upper cover 14. 1141 can be provided, and the motor 1 can be thinned. As shown in FIGS. 18 and 19, the terminal arrangement portion 114 is provided with an outer edge rib 1142 that protrudes downward from the outer edge portion (that is, the external connection terminal 241 side). The strength of the portion outside the cover portion 10 included in the thin region 116 is improved. Further, the terminal arrangement portion 114 has two isolation ribs 1143 protruding on the lower surface (surface on the armature 2 side) between the three external connection terminals 241, and contact between the external connection terminals 241 by the isolation rib 1143. Is disturbed.

  In the connector section 12, the connector 511 on the circuit board 51 and the external connection terminals 241 of the bus bars 24 a to 24 c are adjacent to each other, so that the orientation of the motor 1 can be changed to the operator when performing the connection work to the connector 511 and the external connection terminals 241. On the other hand, the process of changing can be omitted, and the connection work between the various external wirings and the motor 1 can be easily performed. Moreover, since the connector part 12 is located outside the cover part 10, various wirings to the motor 1 can be easily performed even after the motor 1 is assembled.

  FIG. 20 is a longitudinal sectional view of an electric motor 1a according to the second embodiment of the present invention. In FIG. 20, a part of the configuration on the back side of the cross section is also shown, and the cross section is shown without parallel oblique lines. The motor 1a is a motor used as a drive source of an electric slide door mounted on a vehicle, similarly to the motor 1 shown in FIG. 1, and is mounted in a gap between the inner wall and the outer wall of the vehicle. An inner rotor type motor 1a includes an annular armature 2a, a rotor portion 3 inserted into the armature 2a, a bearing mechanism 4 that rotatably supports the rotor portion 3 with respect to the armature 2a, and rotation of the rotor portion 3. A sensor unit 5 for detecting the position, a cover unit 10 covering the armature 2a, a bus bar unit 15 positioned on the upper surface of the armature 2a, and a connector unit 12 for connecting to an external power source or an electric circuit are provided. The inside of the connector portion 12 is a part of the bus bar unit 15.

  The motor 1a is different from the motor 1 of FIG. 1 in that a bus bar unit 15 is provided instead of the bus bar 24 and the resin plate 11, and the structure of the armature 2a is different from that of the armature 2 of FIG. It is the same. The stator cover 13 of the cover portion 10 covers the side surface and the lower surface of the armature 2a, and the armature 2a and the bus bar unit 15 are accommodated by the stator cover 13 and the upper cover 14. In the following description, for convenience, the upper cover 14 side is described as the upper side and the stator cover 13 side is the lower side along the central axis J1, but the central axis J1 does not necessarily coincide with the direction of gravity.

  As in the stator cover 13 according to the first embodiment shown in FIGS. 2 and 3, the stator cover 13 is a bearing in which the inner portion of the bottom annular protrusion 1312 holds the ball bearing 41 of the bearing mechanism 4. A holding portion 1313 is provided. The side wall portion 132 that covers the outer surface of the armature 2a is provided with a plurality of protrusions 1322 that slightly protrude inward, and the lower surface of the core 21 of the armature 2a abuts against the plurality of protrusions 1322, and the armature 2a Is supported, the position of the armature 2a in the axial direction is easily fixed. Further, the stator cover 13 is formed at a low cost by pressing a thin plate-like member, and thereby the axial height of the motor 1a can be kept low.

  The rotor portion 3 has the same structure as the rotor portion 3 of the motor 1 shown in FIG. 14 except that the overall diameter is slightly increased. Similarly to FIG. 15, the rotor core 32 of the rotor portion 3 of the motor 1 a has a recessed portion 325 at the lower portion, and the upper portion of the bearing holding portion 1313 of the stator cover 13 is positioned in the recessed portion 325, so that the axial direction of the motor 1 a Can be kept low.

  The shape of the sensor magnet of the motor 1a is the same as that of the first embodiment (see FIG. 16), the strength of the locking portion is high, and it has high reliability with respect to the rotation prevention of the sensor magnet. Further, the magnet cover of the motor 1a is the same as that of the first embodiment, and separation of the field magnet and the sensor magnet from the rotor core is easily prevented.

  FIG. 21 is a plan view showing the armature 2a. The armature 2a is different from the armature 2 shown in FIGS. 6 to 8 in that the number of teeth 211 is 12 and the shape of the insulator 22c is different. Is the same. The insulator 22c has a shape in which the grooves 221 and the protrusions 225 are omitted from the insulator components 220a and 220b shown in FIGS. 9 and 10, and the coil 23 shown by a two-dot chain line in FIG. The lead wire is wound and formed.

  FIG. 22 is a perspective view showing the bus bar unit 15. The bus bar unit 15 includes a disc portion 151 having an opening into which the shaft 31 is inserted at a central portion, and leg portions 152 provided at five locations on the outer peripheral portion of the disc portion 151. The leg 152 extends outward in the radial direction and protrudes downward, and engages with a notch 2121 provided in the core back element 212 of the armature 2a of FIG. A part of the lower surface of the disc portion 151 is a thin region 156 where the distance in the central axis J1 direction with the armature 2a is increased, and the circuit board 51 of the sensor unit 5 is disposed on the thin region 156. A part of the circuit board 51 protrudes outward from the disk portion 151 as a terminal arrangement portion 512 to which the connector 511 is joined.

  The bus bar unit 15 is formed by integrating three bus bars 25 corresponding to three phases by resin molding, and three external connection terminals 251 of the bus bar 25 protrude side by side on the side of the terminal arrangement portion 512, thereby The wiring work during assembly is simplified. As shown in FIG. 20, the terminal arrangement portion 512 and the external connection terminal 251 are covered from above and below by the connector covers 121 and 122 of the connector portion 12. The internal connection terminals 252 of the bus bar 25 protrude radially outward from the outer surface of the disk portion 151, and four internal connection terminals 252 are provided for each phase. The U, V, and W phase bus bars 25 overlap in the axial direction, and the internal connection terminals 252 of the respective phases sequentially in the circumferential direction (for example, in the order of U, V, and W clockwise around the central axis J1 in FIG. 21). Arranged). Both ends of the conducting wire forming each coil 23 are connected to two adjacent internal connection terminals 252, and each coil 23 is connected to any of U-V, V-W, or W-U to supply current. Is done.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the said embodiment, In addition, various changes are possible in the said embodiment.

  For example, the locking portion 342 of the sensor magnet 34 in FIG. 16 does not need to be arcuate, and may be linear (that is, flat). Further, the locking portion 342 of the sensor magnet 34 may engage with only a part of the through holes 323. The core 21 shown in FIG. 7 is not limited to a set of divided cores 21a in which the teeth 211 are individually formed. For example, the core 21 may be a set of divided cores in which three teeth 211 are set as one set. The whole may be a single core 21.

  As long as the number of protrusions 1322 of the stator cover 13 in FIG. 3 is three or more, any number may be provided in the circumferential direction, and the shape of the bearing holding portions 1313 and 143 is limited to that shown in the above embodiment. Not. The entire bearing holding portions 1313 and 143 may be positioned inside the recess 325 of the rotor core 32 or the sensor magnet 34, and the bearing mechanism 4 may be other than the ball bearings 41 and 42. In the cover portion 10, the upper cover 14 may cover the outer surface of the armature 2, and a plate-like lower cover may be provided instead of the stator cover 13.

  The through-hole 323 of the rotor core 32 shown in FIG. 15 does not need to be completely penetrated as long as it substantially penetrates the rotor core 32. 323 may be closed with a plate-like member or the like. When the radial width of the magnet holding portion 321 is sufficiently secured, the height of the connecting portion 324 of the rotor core 32 in the direction of the central axis J1 is higher than the height of the magnet holding portion 321 that is the outer peripheral portion of the entire connecting portion 324. May be made smaller.

  Further, the magnet cover 35 shown in FIG. 14 does not need to cover all the outer surface, upper surface, and lower surface of the rotor portion 3, and at least the outer peripheral portion of the magnetized surface of the sensor magnet 34 and the sensor magnet 34 of the field magnet 33. By covering the side portion, these magnets can be efficiently held together. Furthermore, the outer surface of the sensor magnet 34 may be a magnetized surface. In this case, the sensor 52 is provided so as to face the outer surface of the sensor magnet 34.

  The insulators 22a and 22b shown in FIGS. 6 and 8 do not have to be provided individually for each tooth 211, and an insulator integrated with the plurality of teeth 211 may be provided. The number of protrusions 225 provided on the first insulator 22a may be four or more. The hole 1121 formed in the welded portion 112 of the resin plate 11 may be a notch as long as the protrusion 225 on the insulator component 220a (see FIG. 9) is inserted and thermally welded.

  The connector part 12 which is an external connection part may be located not on the outer edge part of the armature 2 but on the outer edge part of the armature 2, and there are various shapes and structures of the external connection terminal 241 and the connector 511. May be adopted.

  The motor 1 is not limited to an application as an electric sliding door of an automobile, and may be used as a drive source for a power window or an electric roof. The motor 1 may be used not for automobiles but for other applications.

It is a longitudinal section showing a motor concerning a 1st embodiment. It is a bottom view of a stator cover. It is a longitudinal cross-sectional view of a stator cover. It is a top view of an upper cover. It is a longitudinal cross-sectional view of an upper cover. It is a top view of an armature and a bus bar. It is a top view which shows the core of an armature. It is a top view which shows the core and insulator of an armature. It is a perspective view of an insulator component. It is a perspective view of an insulator component. It is a longitudinal cross-sectional view of a 1st insulator and a division | segmentation core. It is a top view which shows arrangement | positioning of a bus bar. It is a perspective view of the bus bar for U phases. It is an enlarged view of a rotor part vicinity. It is a perspective view of a rotor core. It is a perspective view of the magnet for sensors. It is a perspective view of a resin plate. It is a bottom view of a resin plate. It is a longitudinal cross-sectional view of the vicinity of a terminal arrangement | positioning part. It is a longitudinal cross-sectional view which shows the motor which concerns on 2nd Embodiment. It is a top view of an armature. It is a perspective view of a bus bar unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a Motor 2,2a Armature 3 Rotor part 4 Bearing mechanism 11 Resin plate 13 Stator cover 14 Upper cover 21 Core 24,25 Bus bar 31 Shaft 32 Rotor core 33 Field magnet 34 Sensor magnet 51 Circuit board 52 Sensor 115 Thickness Meat region 116 Thin region 132 Side wall portion 143 Bearing holding portion 325 Recessed portion 1313 Bearing holding portion 1322 Protruding portion J1 Central axis

Claims (7)

An electric motor,
An annular armature,
A rotor portion inserted into the armature;
A bearing mechanism that rotatably supports the rotor portion with respect to the armature around a central axis of the armature;
A lower cover having a bearing holding portion that covers a lower surface of the armature and holds at least a part of the bearing mechanism;
With
The rotor part is
A shaft supported by the bearing mechanism;
A rotor core fixed to the shaft and having a recess in the center of the lower part;
A field magnet attached to the outer periphery of the rotor core;
With
The lower cover is formed by press work,
A motor, wherein a part or the whole of the bearing holding portion of the lower cover is located in the concave portion of the rotor portion. The motor according to claim 1,
The lower cover has a substantially bottomed cylindrical shape having a side wall covering at least the lower part of the outer surface of the armature;
The side wall portion of the lower cover has a plurality of protruding portions that are formed by pressing and protrude inward,
A motor, wherein a lower surface of a core of the armature is in contact with the plurality of protrusions. The motor according to claim 1 or 2,
An upper cover having a bearing holding portion that covers the upper surface of the armature and holds a part of the bearing mechanism;
A sensor for detecting a rotational position of the rotor part;
Further comprising
The rotor portion further includes an annular sensor magnet attached to an upper portion of the rotor core and having an annular magnetized surface facing the sensor;
A motor, wherein a part or all of the bearing holding portion of the upper cover is located inside the sensor magnet of the rotor portion. An electric motor,
An annular armature,
A rotor portion inserted into the armature;
A bearing mechanism that rotatably supports the rotor portion with respect to the armature around a central axis of the armature;
An upper cover that covers a top surface of the armature and has a bearing holding portion that holds at least a part of the bearing mechanism;
A sensor for detecting a rotational position of the rotor part;
With
The rotor part is
A shaft supported by the bearing mechanism;
A rotor core fixed to the shaft;
A field magnet attached to the outer periphery of the rotor core;
An annular sensor magnet attached to an upper portion of the rotor core and having an annular magnetized surface facing the sensor;
With
A motor, wherein a part or all of the bearing holding portion of the upper cover is located inside the sensor magnet of the rotor portion. The motor according to claim 3 or 4,
A substantially plate-shaped resin plate positioned between the armature and the upper cover;
A circuit board fixed to the armature side surface of the resin plate and to which the sensor is attached;
Further comprising
The motor according to claim 1, wherein the resin plate has a thick region and a thin region farther from the armature than the thick region, and the circuit board is attached to the thin region. The motor according to claim 3 or 4,
A substantially plate-shaped resin plate positioned between the armature and the upper cover;
A wiring portion disposed on the armature and serving as a drive current supply path to the armature, and covered with the resin plate;
Further comprising
The resin plate has a thick region and a thin region farther from the armature than the thick region, and the thin region is connected to the armature of the wiring portion; A motor characterized by overlapping. The motor according to any one of claims 1 to 6,
A motor mounted in a gap between an inner wall and an outer wall of an automobile.

Images