Patent Publication Number: US-2019181712-A1

Title: Motor and air conditioner

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a U.S. national stage application of International Patent Application No. PCT/JP2016/072913 filed on Aug. 4, 2016, the disclosure of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a motor and an air conditioner employing the motor. 
     BACKGROUND ART 
     A stator of a motor is generally attached with a ring-shaped substrate (wiring board) having power supply wirings. The substrate is manufactured by being punched from a substrate base material on which wirings and the like are formed. However, since the substrate has a ring shape, the number of substrates punched from the substrate base material having a certain area (obtainable number) is limited. 
     Therefore, Patent Reference 1 proposes a configuration in which a substrate is separated into two arc-shaped substrates, namely, a first arc-shaped substrate and a second arc-shaped substrate. A common pattern is formed on the first arc-shaped substrate, and three power-line-connection patterns connected respectively to U-phase, V-phase and W-phase coils are formed on the second arc-shaped substrate. 
     PATENT REFERENCE 
     Patent Reference 1: Japanese Patent Application Publication No. 2014-11899 (see paragraphs 0024 to 0025) 
     In the above-described configuration, however, in a case where terminals for the coils of the phases are arranged at positions apart from each other on the stator, the second arc-shaped substrate has to be enlarged in order to connect the power-line-connection patterns to the corresponding terminals. Accordingly, the number of substrates obtainable from the substrate base material cannot be increased and reduction in manufacturing cost is difficult. 
     SUMMARY 
     The present invention is made to solve the above-described problem, and an object of the present invention is to increase the number of substrates obtainable from the substrate base material and reduce manufacturing cost of the motor. 
     A motor according to the present invention includes a stator having a stator core in a ring shape, a first coil of a first phase wound around the stator core, and a second coil of a second phase wound around the stator core, a first substrate mounted on the stator and having a first power supply wiring to supply electric power to the first coil, and a second substrate mounted on the stator and having a second power supply wiring to supply electric power to the second coil. 
     An air conditioner according to the present invention includes an outdoor unit having a first fan and a first motor driving the first fan, an indoor unit having a second fan and a second motor driving the second fan, and a refrigerant pipe connecting the outdoor unit and the indoor unit. At least one of the first motor and the second motor has a stator having a stator core in a ring shape, a first coil of a first phase wound around the stator core, and a second coil of a second phase wound around the stator core, a first substrate mounted on the stator and having a first power supply wiring to supply electric power to the first coil, and a second substrate mounted on the stator and having a second power supply wiring to supply electric power to the second coil. 
     According to the present invention, the first substrate has the first power supply wiring and the second substrate has the second power supply wiring. Therefore, the first substrate and the second substrate can be downsized even in a case where a terminal for the first coil and a terminal for the second coil are apart from each other. Accordingly, the number of the substrates obtainable from a substrate base material can be increased and manufacturing cost can be reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a configuration of a stator assembly in a first embodiment of the present invention. 
         FIG. 2  is a plan view showing the configuration of the stator assembly in the first embodiment. 
         FIG. 3  is a plan view showing a configuration of a stator in the first embodiment. 
         FIG. 4  is a side view showing the configuration of the stator in the first embodiment. 
         FIG. 5  is a schematic diagram showing a configuration of a lead wire group in the first embodiment. 
         FIG. 6  is a schematic diagram for explaining a winding pattern of coils in the stator in the first embodiment. 
         FIGS. 7(A) and 7(B)  are schematic diagrams showing the winding pattern of the coils in the stator in the first embodiment in contrast to a comparative example. 
         FIG. 8  is a plan view showing a first substrate and a second substrate in the first embodiment. 
         FIG. 9  is a plan view showing the first substrate and the second substrate in the first embodiment in a separated state. 
         FIG. 10  is a perspective view showing a configuration of a motor in the first embodiment. 
         FIG. 11  is a partially sectional view showing the configuration of the motor in the first embodiment. 
         FIG. 12  is a diagram showing a configuration example of an air conditioner equipped with the motor in the first embodiment. 
         FIG. 13(A)  is a plan view showing a configuration of a stator assembly in a second embodiment of the present invention, and  FIG. 13(B)  is an enlarged sectional view showing a part of the stator assembly. 
         FIG. 14  is a schematic diagram showing the stator assembly and a mold in the second embodiment. 
         FIG. 15  is a plan view showing substrates in a third embodiment of the present invention. 
         FIG. 16  is a plan view showing substrates in a fourth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     First Embodiment 
     (Configuration of Stator Assembly) 
       FIG. 1  is a perspective view showing a configuration of a stator assembly  110  in a first embodiment of the present invention.  FIG. 2  is a plan view showing the configuration of the stator assembly  110 . The stator assembly  110  includes a stator  1 , a substrate  5  mounted on the stator  1 , and a lead wire group  7  connected to the substrate  5 . 
     The stator  1  includes a stator core  10  in a ring shape, an insulator (insulation part)  3  provided on the stator core  10 , and coils  2  wound around the stator core  10 . In the following description, a direction of an axis line C 1  which is a center of the ring-shaped stator  1  will be referred to simply as an “axial direction”. Further, a circumferential direction about the axis line C 1  will be referred to simply as a “circumferential direction”. A radial direction about the axis line C 1  will be referred to simply as a “radial direction”. 
     The substrate  5  is a wiring board (printed circuit board) arranged on one side of the stator core  10  in the axial direction (the upper side in  FIG. 1 ). This substrate  5  is made by combining a first substrate  51  and a second substrate  52  together at a connection part  53  (separation surface). 
     (Configuration of Stator) 
     First, a configuration of the stator  1  will be described.  FIG. 3  is a plan view showing the configuration of the stator  1 .  FIG. 4  is a side view of the stator  1  as viewed in a direction of an arrow IV in  FIG. 3 . The stator core  10  is formed by stacking a plurality of electromagnetic steel sheets in the axial direction and fixing the electromagnetic steel sheets together by means of crimping, welding or adhesion. 
     The stator  1  includes a yoke part  11  in a ring shape about the axis line C 1  and a plurality of teeth  12  (see  FIG. 6 ) each extending inward in the radial direction from the yoke part  11 . The coils  2  are wound around the teeth  12 . Slots accommodating the coils  2  are formed each between adjacent two teeth  12 . The number of the teeth  12  (i.e., the number of the slots) is nine in this example. Such a configuration of a motor is referred to as a 9-slot. However, the configuration is not limited to the 9-slot. 
     The coils  2  are wound around the teeth  12  via the insulator  3 . The insulator  3  electrically insulates the teeth  12  and the coils  2  from each other. The insulator  3  is formed by molding thermoplastic resin such as PBT (polybutylene terephthalate) integrally with the stator core  10  or by mounting previously formed molded bodies on the stator core  10 , for example. The insulator  3  includes an inner wall part  31  and an outer wall part  32  supporting the coils  2  from an inner side and an outer side in the radial direction, in addition to parts covering peripheries of the teeth  12 . 
     On the outer wall part  32  of the insulator  3 , pins  33   a  and  33   b  for fixing the first substrate  51  and pins  33   c  and  33   d  for fixing the second substrate  52  are formed to project in the axial direction. 
     The coils  2  are formed by winding magnet wires around the teeth  12 , for example. The coils  2  are a three-phase winding and includes a coil  2   u  (first coil) of a U-phase (first phase), a coil  2   v  (third coil) of a V-phase (third phase), and a coil  2   w  (second coil) of a W-phase (second phase). Incidentally, the arrangement of the coil  2   u ,  2   v  and  2   w  shown in  FIG. 3  is just an example, and arrangement of the coils is not limited to such arrangement. 
     On the outer wall part  32  of the insulator  3 , a power supply terminal  41   u  (first terminal) to which the U-phase coil  2   u  is connected, a power supply terminal  41   v  (third terminal) to which the V-phase coil  2   v  is connected, and a power supply terminal  41   w  (second terminal) to which the W-phase coil  2   w  is connected. While the power supply terminals  41   u ,  41   v  and  41   w  are arranged at equal intervals around the axis line C 1  in this example, the power supply terminals  41   u ,  41   v  and  41   w  are not necessarily arranged at equal intervals. 
     Further, on the outer wall part  32  of the insulator  3 , a neutral point terminal  42  to which the U-phase coil  2   u  is connected and a neutral point terminal  43  to which the V-phase coil  2   v  and the W-phase coil  2   w  are connected are also provided. The neutral point terminal  42  is arranged between the power supply terminals  41   u  and  41   v  in the circumferential direction. The neutral point terminal  43  is arranged between the power supply terminals  41   v  and  41   w  in the circumferential direction. However, the neutral point terminals  42  and  43  are not limited to such arrangement. 
     The coil  2   u ,  2   v  and  2   w  of the respective phases are respectively connected to the power supply terminals  41   u ,  41   v  and  41   w  and the neutral point terminals  42  and  43  by means of fusing (heat crimping), soldering or the like. 
     (Configuration of Lead Wire Group) 
     As shown in  FIG. 2 , the lead wire group  7  is attached to the substrate  5  (the first substrate  51  and the second substrate  52 ) mounted on the stator core  10 . The lead wire group  7  includes three power supply lead wires  71  and five sensor lead wires  72 . 
       FIG. 5  is a schematic diagram for explaining a configuration of the lead wire group  7 . The power supply lead wires  71  include power supply lead wires  71   u ,  71   v  and  71   w  of the U-phase, V-phase and W-phase. The sensor lead wires  72  include a ground (earth) wiring  72   g , sensor lead wires  72   u ,  72   v  and  72   w  for the U-phase, V-phase and W-phase, and a sensor power supply wiring  72   p.    
     A board-in connector  73  (power supply connector) is attached to tip ends of the power supply lead wires  71 , while an external connection connector  76  is attached to tail ends of the power supply lead wires  71 . A board-in connector  74  (sensor connector) is attached to tip ends of the sensor lead wires  72 , while an external connection connector  77  is attached to tail ends of the sensor lead wires  72 . The board-in connectors  73  and  74  are connected to the first substrate  51  and the second substrate  52 , while the external connection connectors  76  and  77  are connected to an external device or the like. The power supply lead wires  71  and the sensor lead wires  72  are protected from surrounding environment by a protective tube  75 . 
     Incidentally, the three power supply lead wires  71  and the five sensor lead wires  72  are shown in parallel in  FIG. 5 , but in fact the five sensor lead wires  72  are arranged to overlap with the three power supply lead wires  71  in the axial direction. 
     With reference to  FIG. 2  again, the lead wire group  7  includes a lead wire lead-out part  70  for leading the power supply lead wires  71  and the sensor lead wires  72  to an outside of the stator  1 . The lead wire lead-out part  70  is a member having a width in the circumferential direction of the stator core  10  and is mounted between the pins  33   c  and  33   d  in the circumferential direction (width direction). The radial direction at a center of the lead wire lead-out part  70  in the width direction will be referred to as a leading direction of the lead wires  71  and  72  (indicated by an arrow A 1 ). 
     (Arrangement of Coils) 
       FIG. 6  is a schematic diagram for explaining a winding pattern of the coils  2   u ,  2   v  and  2   w . For convenience of explanation, the nine teeth  12  of the stator  1  will be referred to as teeth  12   a ,  12   b ,  12   c ,  12   d ,  12   e ,  12   f ,  12   g ,  12   h  and  12   i  in a clockwise direction in the figure. While the above-described power supply terminals  41   u ,  41   v  and  41   w  are formed respectively at positions corresponding to the teeth  12   a ,  12   d  and  12   g , the positions of the power supply terminals  41   u ,  41   v  and  41   w  are not limited to these positions. 
     Further, among the pins  33   a  to  33   d  ( FIG. 2 ) for fixing the first substrate  51  and the second substrate  52  to the stator  1 , the pin  33   a  is arranged on an outer side of the tooth  12   b  in the radial direction and the pin  33   b  is arranged on an outer side of the tooth  12   e  in the radial direction. The pin  33   c  is arranged on an outer side of the tooth  12   h  in the radial direction and the pin  33   d  is arranged on an outer side of the tooth  12   i  in the radial direction. 
     The coil  2   u  is wound around the three teeth  12   a ,  12   b  and  12   c  adjacent to each other in the circumferential direction among the nine teeth  12   a  to  12   i . Further, the coil  2   v  is wound around the three teeth  12   d ,  12   e  and  12   f  adjacent to each other in the circumferential direction. Further, the coil  2   w  is wound around the three teeth  12   g ,  12   h  and  12   i  adjacent to each other in the circumferential direction. Winding patterns of the coils  2   u ,  2   v  and  2   w  are as described below. 
     The coil  2   u  connected to the power supply terminal  41   u  is first wound around the tooth  12   a , further drawn around via a jumper wire  201  on the outer circumferential side, and wound around the adjacent tooth  12   b . The winding direction of the coil  2   u  around the tooth  12   b  is opposite to the winding direction of the coil  2   u  around the tooth  12   a . The coil  2   u  wound around the tooth  12   b  is further drawn around via a jumper wire  202  on the outer circumferential side and wound around the adjacent tooth  12   c . The winding direction of the coil  2   u  around the tooth  12   c  is opposite to the winding direction of the coil  2   u  around the tooth  12   b.    
     Accordingly, current in the coil  2   u  wound around the tooth  12   b  has a phase inverted by 180 degrees relative to a phase of current in the coil  2   u  wound around the tooth  12   a  or  12   c . The coil  2   u  wound around the tooth  12   a  or  12   c  may be referred to as a U-phase and the coil  2   u  wound around the tooth  12   b  may be referred to as a U-bar phase. 
     The coil  2   v  connected to the power supply terminal  41   v  is first wound around the tooth  12   d , further drawn around via a jumper wire  203  on the outer circumferential side, and wound around the adjacent tooth  12   e . The winding direction of the coil  2   v  around the tooth  12   e  is opposite to the winding direction of the coil  2   v  around the tooth  12   d . The coil  2   v  wound around the tooth  12   e  is further drawn around via a jumper wire  204  on the outer circumferential side and wound around the adjacent tooth  12   f . The winding direction of the coil  2   v  around the tooth  12   f  is opposite to the winding direction of the coil  2   v  around the tooth  12   e.    
     Accordingly, current in the coil  2   v  wound around the tooth  12   e  has a phase inverted by 180 degrees relative to a phase of current in the coil  2   v  wound around the tooth  12   d  or  12   f . The coil  2   v  wound around the tooth  12   d  or  12   f  may be referred to as a V-phase and the coil  2   v  wound around the tooth  12   e  may be referred to as a V-bar phase. 
     The coil  2   w  connected to the power supply terminal  41   w  is first wound around the tooth  12   g , further drawn around via a jumper wire  205  on the outer circumferential side, and wound around the adjacent tooth  12   h . The winding direction of the coil  2   w  around the tooth  12   h  is opposite to the winding direction of the coil  2   w  around the tooth  12   g . The coil  2   w  wound around the tooth  12   h  is further drawn around via a jumper wire  206  on the outer circumferential side and wound around the adjacent tooth  12   i . The winding direction of the coil  2   w  around the tooth  12   i  is opposite to the winding direction of the coil  2   w  around the tooth  12   h.    
     Accordingly, current in the coil  2   w  wound around the tooth  12   h  has a phase inverted by 180 degrees relative to a phase of current in the coil  2   w  wound around the tooth  12   g  or  12   i . The coil  2   w  wound around the tooth  12   g  or  12   i  may be referred to as a W-phase and the coil  2   w  wound around the tooth  12   h  may be referred to as a W-bar phase. 
       FIG. 7(A)  is a schematic diagram showing arrangement of the coils  2   u ,  2   v  and  2   w  in the first embodiment. In this example, the coils  2   u  of the U-phase, U-bar phase and U-phase, the coils  2   v  of the V-phase, V-bar phase and V-phase, and the coils  2   w  of the W-phase, W-bar phase and W-phase are arranged in the clockwise direction in the figure. Such arrangement of the coils is often employed for 8-pole 9-slot motors and 10-pole 9-slot motors, for example. Meanwhile, in such arrangement of the coils, the power supply terminals  41   u ,  41   v  and  41   w  for the coils  2   u ,  2   v  and  2   w  are arranged dispersedly in the circumferential direction. 
       FIG. 7(B)  is a schematic diagram showing arrangement of the coils  2   u ,  2   v  and  2   w  in a comparative example in contrast to the first embodiment. In this comparative example, the number of teeth  12  is twelve (referred to also as 12-slot). In this case, the coils  2   u ,  2   v  and  2   w  of the U-phase, V-phase and W-phase are in turn wound around three teeth  12  adjacent to each other in the circumferential direction, and four sets of such three teeth  12  are provided. In the arrangement of the coils shown in  FIG. 7(B) , the power supply terminals  41   u ,  41   v  and  41   w  for the coils  2   u ,  2   v  and  2   w  are arranged at positions close to each other. 
     In the arrangement shown in  FIG. 7(A) , the power supply terminals  41   u ,  41   v  and  41   w  for the coils  2   u ,  2   v  and  2   w  are arranged dispersedly in the circumferential direction as described above. Therefore, if power supply wirings  6   u ,  6   v  and  6   w  (described later) connected to the power supply terminals  41   u ,  41   v  and  41   w  are mounted on a single substrate, the substrate is necessarily large in size. The number of such large-sized and ring-shaped substrates obtainable from a substrate base material in a manufacturing process is limited and thus it is difficult to reduce the manufacturing cost. 
     This embodiment is intended to reduce the manufacturing cost in the configuration in which the power supply terminals  41   u ,  41   v  and  41   w  of the respective phases are arranged dispersedly in the circumferential direction as described above (for example, 8-pole 9-slot, 10-pole 9-slot or the like). 
     (Configuration of Substrates) 
     Configurations of the first substrate  51  and the second substrate  52  will be explained. This explanation will be given on the assumption that the coils  2   u ,  2   v  and  2   w  of the U-phase, V-phase and W-phase are arranged as shown in  FIG. 3  and  FIG. 6 . However, the arrangement of the coils  2   u ,  2   v  and  2   w  may be modified freely and configurations of the substrates  51  and  52  may also be modified accordingly. 
     As shown in  FIG. 2 , the first substrate  51  and the second substrate  52  constituting the substrate  5  are mounted on one end part (top part) of the stator  1  in the axial direction. The first substrate  51  is arranged in a range covering the power supply terminals  41   u  and  41   v . The second substrate  52  is arranged in a range covering the power supply terminal  41   w . In the example shown in  FIG. 2 , the first substrate  51  is arranged in a range covering the teeth  12   a  to  12   e  ( FIG. 6 ) and the second substrate  52  is arranged in a range covering the teeth  12   g  to  12   i  ( FIG. 6 ). However, the first substrate  51  and the second substrate  52  are not limited to such configurations. 
     The substrates  51  and  52  extend in the circumferential direction and are combined together at the connection part  53  (separation surface). In the example shown in  FIG. 2 , the connection part  53  is formed at a position corresponding to between the teeth  12   a  and  12   i  ( FIG. 6 ). However, the position of the connection part  53  is not limited to this position. The board-in connector  73  is mounted to straddle the connection part  53  between the substrates  51  and  52 . 
     The first substrate  51  includes a terminal insertion hole  5   u  in which the power supply terminal  41   u  is inserted and a terminal insertion hole  5   v  in which the power supply terminal  41   v  is inserted. The first substrate  51  further includes a power supply wiring  6   u  connecting to the terminal insertion hole  5   u  and a power supply wiring  6   v  connecting to the terminal insertion hole  5   v . Each of the power supply wirings  6   u  and  6   v  is an electrically conductive pattern (for example, a copper foil) formed on a back surface of the first substrate  51  (a surface on the stator  1  side). 
     The power supply wiring  6   u  is electrically connected to the power supply terminal  41   u  inserted in the terminal insertion hole  5   u  and supplies electric power to the coil  2   u . The power supply wiring  6   v  is electrically connected to the power supply terminal  41   v  inserted in the terminal insertion hole  5   v  and supplies electric power to the coil  2   v.    
     The first substrate  51  further includes engagement holes  5   a  and  5   b  respectively engaging with the pins  33   a  and  33   b  of the stator  1 . The pins  33   a  and  33   b  are thermally welded in a state where the pins  33   a  and  33   b  engage with the holes  5   a  and  5   b , and thus the first substrate  51  is fixed to the stator  1 . 
     The second substrate  52  includes a terminal insertion hole  5   w  in which the power supply terminal  41   w  is inserted. The second substrate  52  further includes a power supply wiring  6   w  connecting to the terminal insertion hole  5   w . The power supply wiring  6   w  is an electrically conductive pattern (for example, a copper foil) formed on a back surface of the second substrate  52  (a surface on the stator  1  side). The power supply wiring  6   w  is electrically connected to the power supply terminal  41   w  inserted in the terminal insertion hole  5   w  and supplies electric power to the coil  2   w.    
     The second substrate  52  further includes engagement holes  5   c  and  5   d  respectively engaging with the pins  33   c  and  33   d  of the stator  1 . The pins  33   c  and  33   d  are thermally welded in the state where the pins  33   c  and  33   d  engage with the engagement holes  5   c  and  5   d , and thus the second substrate  52  is fixed to the stator  1 . 
       FIG. 8  is a plan view showing the configurations of the substrates  51  and  52 . The connection part  53  between the substrates  51  and  52  extends inward in the radial direction from an edge part of the substrates  51  and  52  on the outer circumferential side, changes its direction at a position where the connection part  53  passes an edge part of the stator core  10  on the inner circumferential side, extends in the above-described leading direction of the lead wires  71  and  72  (the direction indicated by the arrow A 1 ), and reaches an edge part of the substrates  51  and  52  on the inner circumferential side. Incidentally, a position where the connection part  53  is formed is not limited to the position shown in  FIG. 8 , and it is sufficient that the connection part  53  is formed at a position where the substrates  51  and  52  can be separated without interfering with the power supply wirings  6   u ,  6   v  and  6   w.    
     The connection part  53  includes a concave part  53   a  formed on the first substrate  51  and a convex part  53   b  formed on the second substrate  52 . The concave part  53   a  and the convex part  53   b  engage with each other, and thus the substrates  51  and  52  are connected together. The concave part  53   a  and the convex part  53   b  constitute an engagement part (first connection part). Incidentally, it is also possible to form a convex part on the first substrate  51  and a concave part on the second substrate  52 . Further, the substrates  51  and  52  may have any forms engaging with each other, not limited to a combination of the concave part and the convex part. 
     On the first substrate  51 , a connection terminal part  61   u  of the power supply wiring  6   u  (first connection terminal part) and a connection terminal part  61   v  of the power supply wiring  6   v  (third connection terminal part) are arranged in a region between the connection part  53  and the terminal insertion hole  5   u . The connection terminal part  61   u  is located above the tooth  12   a  ( FIG. 6 ), for example. The connection terminal part  61   v  is arranged between the connection terminal part  61   u  and the connection part  53 , for example. Further, a connection terminal part  61   w  of the power supply wiring  6   w  (second connection terminal part) is arranged at a position facing the connection terminal part  61   v  across the connection part  53 . 
     The connection terminal parts  61   u ,  61   v  and  61   w  are arranged in a row in a direction perpendicular to the aforementioned leading direction of the lead wires  71  and  72  (the direction indicated by the arrow A 1 ). The aforementioned board-in connector  73  ( FIG. 5 ) is joined to these connection terminal parts  61   u ,  61   v  and  61   w . Thus, the U-phase, V-phase and W-phase currents respectively flow from the power supply lead wires  71   u ,  71   v  and  71   w  to the power supply wirings  6   u ,  6   v  and  6   w  via the connection terminal parts  61   u ,  61   v  and  61   w  and are supplied to the power supply terminals  41   u ,  41   v  and  41   w.    
     On the back surface of the second substrate  52  (the surface on the stator  1  side), a Hall effect sensors (Hall ICs)  62  are arranged along an inner circumference of the stator core  10  ( FIG. 3 ). The Hall effect sensors  62  are used to detect a rotational position of a rotor  8 , and include Hall effect sensors  62   u ,  62   v  and  62   w  for the U-phase, V-phase and W-phase. 
     The second substrate  52  is provided with a connection terminal part  64  in a region between the engagement holes  5   c  and  5   d  in the circumferential direction. The connection terminal part  64  is connected to the Hall effect sensors  62   u ,  62   v  and  62   w  by not shown wiring parts. The connection terminal part  64  has five terminal parts, to which the above-described board-in connector  74  ( FIG. 5 ) is joined. Thus, voltages are applied to the Hall effect sensors  62   u ,  62   v  and  62   w  via the ground wiring  72   g  and the sensor power supply wiring  72   p . Output voltages of the Hall effect sensors  62   u ,  62   v  and  62   w  are outputted to an external device via the sensor lead wires  72   u ,  72   v  and  72   w.    
     An edge part of the first substrate  51  on the outer circumferential side includes outer circumferential arc parts  511  and  513  extending arcuately along an outer circumference of the stator core  10  and an outer circumferential straight part  512  extending straight to form a chord between the outer circumferential arc parts  511  and  513 . The outer circumferential arc part  511  extends from the connection part  53  to a position where the engagement hole  5   a  is formed. The outer circumferential straight part  512  extends in parallel with the above-described power supply wiring  6   v . The outer circumferential arc part  513  extends from a position where the terminal insertion hole  5   v  is formed to a position where the engagement hole  5   b  is formed. 
     An edge part of the first substrate  51  on the inner circumferential side includes an inner circumferential straight part  514  formed to be continuous with the connection part  53 , an inner circumferential arc part  515  formed to be continuous with the inner circumferential straight part  514 , and an inner circumferential straight part  516  formed to be continuous with the inner circumferential arc part  515 . The inner circumferential straight parts  514  and  516  extend in the direction perpendicular to the above-described leading direction of the lead wires  71  and  72  (the arrow A 1 ). 
     An edge part of the second substrate  52  on the outer circumferential side includes an outer circumferential arc part  521  extending arcuately along the outer circumference of the stator core  10  and a groove-shaped part  522  formed in a middle of the outer circumferential arc part  521 . The groove-shaped part  522  is arranged between the engagement holes  5   c  and  5   d  in the circumferential direction. A position where the groove-shaped part  522  is formed corresponds to a position where the board-in connector  74  is attached. 
     An edge part of the second substrate  52  on the inner circumferential side includes an inner circumferential straight part  525  parallel with and facing the inner circumferential straight part  516  of the first substrate  51  and a groove-shaped part  526  formed in the inner circumferential straight part  525 . The groove-shaped part  526  is formed at a position facing the above-described groove-shaped part  522 . The inner circumferential straight part  525  of the second substrate  52  and the inner circumferential straight part  514  of the first substrate  51  extend on the same straight line in the direction perpendicular to the leading direction of the lead wires  71  and  72  (the arrow A 1 ). 
     Among the above-described power supply wirings  6   u ,  6   v  and  6   w , the power supply wiring  6   u  is the shortest and extends in the radial direction from the terminal insertion hole  5   u  to the connection terminal part  61   u . The power supply wiring  6   v  is the longest, extends in parallel with the outer circumferential straight part  512  from the terminal insertion hole  5   v , bends and then extends straight in a region between the outer circumferential arc part  511  and the inner circumferential arc part  515 , bends further and extends straight to the connection terminal part  61   v . The power supply wiring  6   w  extends in parallel with the inner circumferential straight part  525  from the terminal insertion hole  5   w , then detours outward in the radial direction, extends straight between the connection terminal part  64  and the groove-shaped part  522 , further changes its direction to be in parallel with the leading direction of the lead wires  71  and  72  (the arrow A 1 ), and reaches the connection terminal part  61   w.    
       FIG. 9  is a diagram showing a state in which the first substrate  51  and the second substrate  52  are separated. Both of the separated first substrate  51  and second substrate  52  have small dimensions in the radial direction. Therefore, in the manufacturing process, the numbers of the substrates  51  and  52  obtainable from the substrate base material can be increased by forming a plurality of first substrates  51  and a plurality of second substrates  52  to be arranged in a staggered manner in the substrate base material, and punching the substrates  51  and  52  from the substrate base material. 
     (Configuration of Motor) 
       FIG. 10  is a perspective view showing an external shape of a motor  100  (referred to also as a mold motor) including the stator  1 .  FIG. 11  is a partially sectional view showing a configuration of the motor  100 . The motor  100  includes the stator assembly  110  having the stator  1 , a mold resin  13  covering the stator assembly  110 , and the rotor  8  rotatably arranged inside the stator  1 . 
     The mold resin  13  is thermosetting resin such as bulk molding compound (BMC), for example. However, the mold resin  13  is not limited to thermosetting resin, but may be thermoplastic resin, for example. The mold resin  13  covers the stator  1  from outside in the radial direction and both sides in the axial direction in such a manner that the inner circumferential surface of the stator  1  is exposed. 
     As shown in  FIG. 11 , an end part  18  of the stator  1  in the axial direction on the side to which the substrate  5  (the first substrate  51  and the second substrate  52 ) is attached is covered with the mold resin  13 . However, a part of the lead wire lead-out part  70  is exposed. An opening part  19  is formed in an end part of the stator assembly  110  in the axial direction on the side opposite to the substrate  5 . 
     The rotor  8  is inserted through the opening part  19  of the stator  1  and then faces inner circumferential ends of the teeth  12  of the stator  1 . The rotor  8  includes a rotor core  81  in a cylindrical shape and formed of a stack of electromagnetic steel sheets, a plurality of magnets  82  embedded in the rotor core  81 , and a shaft  83  penetrating a center of the rotor core  81 . A central axis line of the shaft  83  coincides with the above-described axis line C 1 . The magnets  82  are arranged at equal intervals in the circumferential direction of the rotor core  81 . The number of the magnets  82  is eight or ten, for example. 
     A sensor magnet  87  is attached to the magnets  82  on the substrate  5  side (the right side in  FIG. 11 ). Each of the Hall effect sensors  62  attached to the second substrate  52  is arranged to face the sensor magnet  87  at a position shifted in the radial direction from the sensor magnet  87 . The Hall effect sensors  62  detect magnetic flux from the sensor magnet  87  and thereby detect a rotational position of the rotor  8 . 
     The shaft  83  of the rotor  8  is supported by a pair of bearings  84 . One of the bearings  84  is held by the mold resin  13  at the end part  18  of the stator  1 . The other of the bearings  84  is held by a bracket  85  provided in the opening part  19  of the stator  1 . 
     (Manufacturing Process of Motor) 
     A manufacturing process of the motor  100  is as described below. First, the insulator  3  is formed by molding thermoplastic resin integrally with the stator core  10  formed of the stack of electromagnetic steel sheets or by mounting previously molded thermoplastic resin on the stator core  10 . Further, the coils  2   u ,  2   v  and  2   w  are wound around the teeth  12   a  to  12   i  of the stator core  10  as shown in  FIG. 6  via the insulator  3 . Thus, the stator  1  is completed. 
     Further, one substrate  5  is formed by combining the first substrate  51  and the second substrate  52  together at the connection part  53  and engaging the concave part  53   a  and the convex part  53   b  with each other, and the lead wire group  7  is connected to the substrate  5 . Specifically, the board-in connector  73  is joined to the connection terminal parts  61   u ,  61   v  and  61   w  and the board-in connector  74  is joined to the connection terminal part  64 . 
     The substrate  5  (the first substrate  51  and the second substrate  52 ) to which the lead wire group  7  is connected as above is mounted on the stator  1 . In this step, the pins  33   a  to  33   d  of the stator  1  are respectively engaged with the engagement holes  5   a ,  5   b ,  5   c  and  5   d  of the substrates  51  and  52  and thermally welded. 
     Further, the power supply terminals  41   u ,  41   v  and  41   w  of the stator  1  are engaged with the terminal insertion holes  5   u ,  5   v  and  5   w  of the substrates  51  and  52  and connected to the power supply wirings  6   u ,  6   v  and  6   w  by means of soldering or the like. Thus, the stator assembly  110  is completed. 
     Thereafter, the stator assembly  110  is molded with mold resin such as BMC. Specifically, the stator assembly  110  is set in a mold and the mold resin is injected into the mold. In a case where thermosetting resin is used as the mold resin, the mold resin is cured by heating the mold. Thus, the stator assembly  110  is covered with the mold resin. Incidentally, as described above, the mold resin is not limited to thermosetting resin and may be thermoplastic resin, for example. 
     After this molding step, the motor  100  is assembled. Specifically, the bearings  84  are attached to the shaft  83  of the rotor  8 , and the rotor  8  is inserted through the opening part  19  of the stator  1 . Further, the bracket  85  is attached to the opening part  19  of the stator  1 . Furthermore, a waterproof cap  86  inhibiting intrusion of water or the like into the bearings  84  is attached to an outer side of the bracket  85 . Thus, the manufacture of the motor  100  is completed. 
     (Configuration of Air Conditioner) 
     Next, an air conditioner  300  including the motor  100  in this embodiment will be described.  FIG. 12  is a diagram showing a configuration example of the air conditioner  300 . The air conditioner  300  includes an outdoor unit  301 , an indoor unit  302 , and a refrigerant pipe  303  connecting the outdoor unit  301  and the indoor unit  302 . 
     The outdoor unit  301  includes a first fan (blower)  305  and a first motor  306  driving the first fan  305 . The indoor unit  302  includes a second fan  307  and a second motor  308  driving the second fan  307 . At least one of the first motor  306  and the second motor  308  is formed of the motor  100  in this embodiment. Incidentally, a compressor  309  compressing refrigerant in the outdoor unit  301  is also shown in  FIG. 12 . 
     For example, in a case where the first motor  306  is constituted by the motor  100  ( FIG. 11 ) in this embodiment, as the rotor  8  ( FIG. 11 ) of the motor  100  rotates, the first fan  305  rotates and blows air to an outside of the room. Heat emitted when the refrigerant compressed by the compressor  309  is condensed in a condenser (not shown) is discharged to the outside of the room by the air blown out by the first fan  305 . 
     Effects of Embodiment 
     As described above, in the first embodiment of the present invention, the substrate  5  to be mounted on the stator  1  is separated into the first substrate  51  and the second substrate  52 , the first substrate  51  includes the first power supply wiring (for example, the power supply wiring  6   u ), and the second substrate  52  includes the second power supply wiring (for example, the power supply wiring  6   w ). Therefore, the substrates  51  and  52  can be configured to be small in size even in a case where the power supply terminals  41   u ,  41   v  and  41   w  are arranged apart from each other. Accordingly, the numbers of the substrates  51  and  52  obtainable from the substrate base material can be increased and the manufacturing cost can be reduced. 
     Further, since the first substrate  51  and the second substrate  52  are connected together by the engagement of the concave part  53   a  and the convex part  53   b  (engagement part), mounting position accuracy of the substrates  51  and  52  with respect to the stator  1  and rigidity of the substrates  51  and  52  can be increased and performance of the motor  100  can be enhanced. Further, the manufacturing process can be simplified since the substrates  51  and  52  can be handled as one substrate  5 . 
     Further, since the first substrate  51  includes the power supply wirings  6   u  and  6   v  for two phases (for example, the U-phase and the V-phase) and the second substrate  52  includes the power supply wiring  6   w  for the remaining one phase (for example, the W-phase), the electric power supply to the power supply terminals  41   u ,  41   v  and  41   w  of the U-phase, V-phase and W-phase can be carried out without enlarging the substrates  51  and  52 . 
     Further, the first substrate  51  has the terminal insertion holes  5   u  and  5   v  in which the power supply terminals  41   u  and  41   v  are inserted and the second substrate  52  has the terminal insertion hole  5   w  in which the power supply terminal  41   w  is inserted. Therefore, the power supply wirings  6   u ,  6   v  and  6   w  can be electrically connected to the power supply terminals  41   u ,  41   v  and  41   w , respectively. 
     Further, since the board-in connector  73  (power supply connector) is joined to the connection terminal parts  61   u  and  61   v  of the first substrate  51  and the connection terminal part  61   w  of the second substrate  52 , electric power supply to the coils  2   u ,  2   v  and  2   w  of the respective phases can be carried out using one board-in connector  73  and the manufacturing cost can be reduced further. It is also possible to make the board-in connector  73  have a role to connect the first substrate  51  and the second substrate  52  together. 
     Further, since the first substrate  51  has the engagement holes  5   a  and  5   b  engaging with the pins  33   a  and  33   b  and the second substrate  52  has the engagement holes  5   c  and  5   d  engaging with the pins  33   c  and  33   d , the mounting position accuracy of the substrates  51  and  52  with respect to the stator  1  can be increased further. 
     Further, since the second substrate  52  includes the Hall effect sensors  62 , it is possible to make the Hall effect sensors  62  face the sensor magnet  87  without enlarging the substrates  51  and  52 . Further, since the board-in connector  74  is connected to the connection terminal part  64  of the second substrate  52 , output signals of the Hall effect sensors  62  can be taken out with a simple configuration. 
     Further, by employing the above-described motor  100  as a drive source of the fan of the air conditioner  300 , the manufacturing cost of the air conditioner  300  can be reduced. 
     Second Embodiment 
     Next, a second embodiment of the present invention will be described.  FIG. 13(A)  is a plan view showing a stator assembly  111  in the second embodiment. In this second embodiment, the first substrate  51  and the second substrate  52  are connected together using a substrate retaining member  9  arranged on the first substrate  51  and the second substrate  52 . 
     (Configuration of Substrate Retaining Member) 
     The substrate retaining member (connection member)  9  includes a plurality of ribs  90  extending in the form of a framework in a plane perpendicular to the axial direction and a plurality of projections  92  each projecting from the rib  90  toward an opposite side to the stator  1  (the upper side in  FIG. 1 ). The substrate retaining member  9  is formed of resin such as PBT, for example. 
     The ribs  90  include a rib  90   a  extending along an edge part of the first substrate  51  on the inner circumferential side, a rib  90   b  extending along an edge part of the first substrate  51  on the outer circumferential side, a rib  90   c  extending along an edge part of the second substrate  52  on the inner circumferential side, and a rib  90   d  extending along an edge part of the second substrate  52  on the outer circumferential side. The ribs  90  further include a rib  90   e  connecting the ribs  90   a  and  90   b  together in the radial direction and a rib  90   f  connecting the ribs  90   c  and  90   d  together in the radial direction. The ribs  90  further include ribs  90   g  connecting the ribs  90   a  and  90   b  on the first substrate  51  and the ribs  90   c  and  90   d  on the second substrate  52  together. Incidentally, the shape of the ribs  90  is not limited to the shape described here, and any shape capable of retaining the whole of the first substrate  51  and the second substrate  52  from above (the side opposite to the stator  1  side) may be employed. 
     The projections  92  are arranged in a great number throughout the whole of the ribs  90   a  to  90   g . Further, holding parts  91  for holding the first substrate  51  are formed on the ribs  90   a  and  90   b  on the inner and outer circumferential sides of the first substrate  51 . Similarly, holding parts  91  for holding the second substrate  52  are formed on the ribs  90   c  and  90   d  on the inner and outer circumferential sides of the second substrate  52 . 
       FIG. 13(B)  is a diagram schematically showing a configuration of the holding part  91 , which corresponds to a sectional view at a line segment  13 B- 13 B shown in  FIG. 13(A)  as viewed in a direction of arrows. The holding part  91  extends downward, i.e., toward the stator  1 , from the rib  90  (the rib  90   a  in this example) and has a hook part (locking part)  93  at its lower end. The hook part  93  is configured to contact a lower surface of the first substrate  51  (the surface facing the stator  1 ). While the holding part  91  holding the first substrate  51  is shown in  FIG. 13(B) , the holding part  91  holding the second substrate  52  is also configured in the same way. 
     Accordingly, when the substrate retaining member  9  is attached onto the first substrate  51  and the second substrate  52 , the holding parts  91  of the substrate retaining member  9  hold the first substrate  51  and the second substrate  52 . Namely, the first substrate  51  and the second substrate  52  are connected together by the substrate retaining member  9 . 
     The substrate retaining member  9  has engagement holes  95   a ,  95   b ,  95   c  and  95   d  at positions corresponding to the pins  33   a ,  33   b ,  33   c  and  33   d  of the stator  1 . The pins  33   a ,  33   b ,  33   c  and  33   d  of the stator  1  engage with the engagement holes  5   a ,  5   b ,  5   c  and  5   d  of the first substrate  51  and the second substrate  52  and further engage with the engagement holes  95   a ,  95   b ,  95   c  and  95   d  of the substrate retaining member  9 . 
     Incidentally, while the holding part  91  shown in  FIG. 13(B)  is formed in a part of the rib  90  where the projection  92  is arranged, the holding part  91  may be formed at a position separate from the projection  92 . 
     In this second embodiment, the first substrate  51  and the second substrate  52  are connected together using the substrate retaining member  9 , and thus it is unnecessary to provide the engagement part (the concave part  53   a  and the convex part  53   b ) described in the first embodiment. However, it is also possible to provide the engagement part (the concave part  53   a  and the convex part  53   b ) in addition to using the substrate retaining member  9 . 
     The rest of the configuration of the motor in the second embodiment is substantially the same as that in the first embodiment. The motor in the second embodiment can be employed for the air conditioner  300  described with reference to  FIG. 12 , for example. 
     (Manufacturing Process of Motor) 
     In the manufacturing process of the motor in this second embodiment, the first substrate  51  and the second substrate  52  are individually mounted on the stator  1  and thereafter the substrate retaining member  9  is attached onto the first substrate  51  and the second substrate  52 . In this case, the holding parts  91  (the hook parts  93 ) of the substrate retaining member  9  hold the first substrate  51  and the second substrate  52  as shown in  FIG. 13(B) , and thus the first substrate  51  and the second substrate  52  are connected together. Incidentally, it is also possible to first integrate the first substrate  51  and the second substrate  52  together by attaching the substrate retaining member  9  and thereafter mount the integrated substrate  5  on the stator  1 . 
     Thereafter, the substrate  5  and the substrate retaining member  9  are fixed to the stator  1  by thermally welding the pins  33   a ,  33   b ,  33   c  and  33   d  penetrating the engagement holes  5   a ,  5   b ,  5   c  and  5   d  of the substrate  5  and the engagement holes  95   a ,  95   b ,  95   c  and  95   d  of the substrate retaining member  9 . Thus, the stator assembly  111  shown in  FIG. 13(A)  is obtained. 
       FIG. 14  is a schematic diagram for explaining a configuration of a mold  400  used in a mold step in the second embodiment. The mold  400  is configured to include an upper mold  401  and a lower mold  402  which are openable and closable, and a cavity  404  is formed between the upper mold  401  and the lower mold  402 . A runner  406  as a channel for injecting resin into the cavity  404  is formed between the upper mold  401  and the lower mold  402 . The runner  406  is connected to an upper end part of the cavity  404 . 
     A center core  403  in a cylindrical shape is formed in the lower mold  402 , and the center core  403  projects toward an inside of the cavity  404 . The center core  403  is a part engaging with an inner surface of the stator core  10 . A larger-diameter part  407  projecting outward in the radial direction from the center core  403  is formed at a lower end part of the center core  403 . This larger-diameter part  407  is a part corresponding to the opening part  19  ( FIG. 11 ) of the stator  1 . 
     At the time of molding, the cavity  404  is opened by moving the upper mold  401  upward, and the stator assembly  111  (including the stator  1 , the substrate  5  and the substrate retaining member  9 ) is set in the cavity  404 . A part of the lead wire lead-out part  70 , parts of the power supply lead wires  71  and parts of the sensor lead wires  72  project to an outside of the cavity  404 . 
     Thereafter, the cavity  404  is closed by moving the upper mold  401  downward, and the mold resin in a molten state is injected into the cavity  404  through the runner  406 . The mold resin injected into the cavity  404  covers the stator assembly  111 . 
     In a case where thermosetting resin is used as the mold resin, the stator assembly  111  is molded by injecting the mold resin into the cavity  404  and thereafter curing the mold resin in the cavity  404  by heating the mold  400 . As described above, the mold resin is not limited to thermosetting resin and may be thermoplastic resin, for example. At the time of molding, the projections  92  of the substrate retaining member  9  are in contact with a top surface of the cavity  404 , and thus deformation of the substrate  5  (the first substrate  51  and the second substrate  52 ) due to molding pressure is inhibited. Incidentally, it is also possible that lower surfaces of the hook parts  93  ( FIG. 13(B) ) of the holding parts  91  of the substrate retaining member  9  are in contact with the mold  400 . 
     Thereafter, the molded stator assembly  111  is taken out of the mold  400 , and the rotor  8  is mounted in the stator  1  of the stator assembly  111  as described in the first embodiment, and thus the motor is assembled. 
     Effects of Embodiment 
     As described above, in the second embodiment of the present invention, the first substrate  51  and the second substrate  52  are connected together using the substrate retaining member  9 , and thus the first substrate  51  and the second substrate  52  can be integrated together more firmly. Accordingly, the mounting position accuracy of the first substrate  51  and the second substrate  52  with respect to the stator  1  and the rigidity of the first substrate  51  and the second substrate  52  can be increased, and the performance of the motor  100  can be enhanced. 
     Further, since the substrate retaining member  9  includes the projections  92  contacting the top surface of the cavity  404  of the mold  400 , it is possible to prevent the deformation of the first substrate  51  and the second substrate  52  at the time of molding and thereby contribute to enhancement in quality of the motor. 
     Third Embodiment 
     Next, a third embodiment of the present invention will be described.  FIG. 15  is a plan view showing a configuration of a substrate  501  in the third embodiment. The substrate  5  in the first embodiment described above is separated into the first substrate  51  and the second substrate  52 . In contrast, the substrate  501  in the third embodiment is separated into a first substrate  51  and a second substrate  52 , and the first substrate  51  is further separated into substrates  51 A and  51 B. 
     (Configuration of Substrates) 
     The substrate  51 A (first substrate) is configured as a part including the U-phase power supply wiring  6   u  and the terminal insertion hole  5   u . The substrate  51 B (third substrate) is configured as a part including the V-phase power supply wiring  6   v  and the terminal insertion hole  5   v . Further, the substrate  51 A has an engagement hole  5   a  engaging with the pin  33   a  ( FIG. 2 ) of the stator  1 , and the substrate  51 B has an engagement hole  5   b  engaging with the pin  33   b  ( FIG. 2 ) of the stator  1 . 
     A connection part  56  (separation surface) is formed between the substrates  51 A and  51 B. The connection part  56  includes a concave part  56   a  formed on the substrate  51 A and a convex part  56   b  formed on the substrate  51 B. The concave part  56   a  and the convex part  56   b  engage with each other, and thus the substrates  51 A and  51 B are connected together. The concave part  56   a  and the convex part  56   b  constitute an engagement part (second connection part). Incidentally, it is also possible to form the convex part on the substrate  51 A and the concave part on the substrate  51 B. Further, the substrates  51 A and  51 B may have any forms engaging with each other, not limited to a combination of the concave part and the convex part. 
     The second substrate  52  is configured similarly to the second substrate  52  ( FIG. 8 ) in the first embodiment. Accordingly, by engaging the convex part  53   b  of the second substrate  52  and the concave part  53   a  of the substrate  51 A with each other and engaging the concave part  56   a  of the substrate  51 A and the convex part  56   b  of the substrate  51 B with each other, the substrates  51 A,  51 B and  52  can be connected together. It is also possible to connect the substrates  51 A,  51 B and  52  together using the substrate retaining member  9  described in the second embodiment instead of using the engagement of the concave parts and the convex parts. 
     Incidentally, while the connection part  56  extends from the connection part  53  to the outer circumferential straight part  512  in the example shown in  FIG. 15 , the connection part  56  may be formed at any position as long as the substrates  51 A and  51 B can be separated without interfering with the power supply wirings  6   u  and  6   v.    
     Effects of Embodiment 
     As described above, in the third embodiment of the present invention, the substrate  501  is separated into the substrate  51 A (first substrate) including the power supply wiring  6   u , the substrate  51 B (third substrate) including the power supply wiring  6   v , and the second substrate  52  including the power supply wiring  6   w . Therefore, the substrates  51 A,  51 B and  52  can be configured to be small in size even in the case where the power supply terminals  41   u ,  41   v  and  41   w  of the stator  1  are arranged apart from each other. Accordingly, the numbers of the substrates obtainable from the substrate base material can be increased and the manufacturing cost can be reduced. 
     Further, since the substrates  51 A,  51 B and  52  are connected together by the concave part  53   a  and the convex part  53   b  (first engagement part) and the concave part  56   a  and the convex part  56   b  (second engagement part), the mounting position accuracy of the substrates  51 A,  51 B and  52  with respect to the stator  1  and the rigidity of the substrates  51 A,  51 B and  52  can be increased. 
     Fourth Embodiment 
     Next, a fourth embodiment of the present invention will be described.  FIG. 16  is a plan view showing a configuration of a substrate  502  in the fourth embodiment. The substrate  5  in the first embodiment described above is separated into the first substrate  51  and the second substrate  52 . In contrast, the substrate  502  in the fourth embodiment is separated into a first substrate  51  and a second substrate  52 , and the second substrate  52  is further separated into substrates  52 A and  52 B. 
     (Configuration of Substrates) 
     The substrate  52 A (second substrate) is configured as a part including the power supply wiring  6   w  of the W-phase and the terminal insertion hole  5   w . The substrate  52 B (fourth substrate) is configured as a part including the Hall effect sensors  62   u ,  62   v  and  62   w  and their connection terminal part  64 . Further, the substrate  52 A has engagement holes  5   c  and  5   d  engaging with the pins  33   c  and  33   d  ( FIG. 2 ) of the stator  1 . 
     A connection part  57  (separation surface) is formed between the substrates  52 A and  52 B. The connection part  57  includes a concave part  57   a  formed on the substrate  52 A and a convex part  57   b  formed on the substrate  52 B. The concave part  57   a  and the convex part  57   b  engage with each other, and thus the substrates  52 A and  52 B are connected together. The concave part  57   a  and the convex part  57   b  constitute an engagement part (third connection part). Incidentally, it is also possible to form the convex part on the substrate  52 A and the concave part on the substrate  52 B. Further, the substrates  52 A and  52 B may have any forms engaging with each other, not limited to a combination of the concave part and the convex part. 
     The first substrate  51  is configured similarly to the first substrate  51  ( FIG. 8 ) in the first embodiment. Accordingly, by engaging the concave part  53   a  of the first substrate  51  and the convex part  53   b  of the second substrate  52  with each other and engaging the concave part  57   a  of the substrate  52 A and the convex part  57   b  of the substrate  52 B with each other, the substrates  51 ,  52 A and  52 B can be connected together. It is also possible to connect the substrates  51 ,  52 A and  52 B together using the substrate retaining member  9  described in the second embodiment instead of using the engagement of concave and convex parts. 
     Incidentally, while the connection part  57  extends from the inner circumferential straight part  525  to an end of the groove-shaped part  526  described in the first embodiment in the example shown in  FIG. 16 , the connection part  57  may be formed at any position as long as the substrates  52 A and  52 B can be separated without interfering with the power supply wiring  6   w , the Hall effect sensors  62   u ,  62   v  and  62   w  and the connection terminal part  64 . 
     Effects of Embodiment 
     As described above, in the fourth embodiment of the present invention, the substrate  502  is separated into the first substrate  51  including the power supply wiring  6   u  and the power supply wiring  6   v , the substrate  52 A (second substrate) including the power supply wiring  6   w , and the substrate  52 B (fourth substrate) including the Hall effect sensors  62   u ,  62   v  and  62   w . Therefore, the substrates  51 ,  52 A and  52 B can be configured to be small in size. Accordingly, the numbers of the substrates obtainable from the substrate base material can be increased and the manufacturing cost can be reduced. 
     Further, since the substrates  51 ,  52 A and  52 B are connected together by the concave part  53   a  and the convex part  53   b  (first engagement part) and the concave part  57   a  and the convex part  57   b  (third engagement part), the mounting position accuracy of the substrates  51 ,  52 A and  52 B with respect to the stator  1  and the rigidity of the substrates  51 ,  52 A and  52 B can be increased. 
     Furthermore, depending on a form of use of the motor, there may be a case where the Hall effect sensors  62   u ,  62   v  and  62   w  are not used. In such a case, it is also possible to use the motor while the substrate  52 B is removed from the substrate  502 . 
     Incidentally, in the fourth embodiment, it is also possible to further separate the first substrate  51  into the substrates  51 A and  51 B as described in the third embodiment. 
     While preferred embodiments of the present invention have been described specifically above, the present invention is not limited to the above-described embodiments and a variety of improvements or modifications are possible within the range not departing from the subject matter of the present invention.