Patent Publication Number: US-8536467-B2

Title: Connecting structure for electric cables and electric apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to a connecting structure for electric cables in an electric apparatus such as an electric motor. 
     BACKGROUND ART 
     Japanese Patent Application Publication No. 2006-333664 (JP2006-333664A) discloses a connecting structure for electric cables for electrically connecting an electric apparatus unit disposed in a casing for an electric apparatus such as a stepping motor to a plurality of electric cables disposed outside the casing. The electric apparatus unit includes a circuit substrate having a connection circuit pattern formed thereon. The cores of the electric cables are soldered to the circuit substrate of the electric apparatus unit. A portion where the circuit substrate of the electric apparatus unit and the electric cables are connected is molded of an electrically insulating resin. 
     According to conventional approaches, a connector is disposed on a wall portion of the casing to detachably connect the electric cables to the electric apparatus, and then the connector and the electric apparatus unit are electrically connected by some appropriate means. 
     The connecting structure for electric cables disclosed in JP 2006-333664A does not allow for electrical connection of the electric cables to the electric apparatus unit outside the casing, thereby complicating the connection of the electric cables and allowing no freedom to determine the length of the electric cables. A connecting structure for electric cables using a connector needs a dedicated connector, thereby increasing the overall costs. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a low-priced connecting structure for electric cables, capable of connecting electric cables disposed outside a casing for an electric apparatus to the electric apparatus unit disposed inside the casing, and an electric apparatus using such connecting structure for electric cables. 
     Another object of the present invention is to provide a connecting structure for electric cables capable of utilizing existing parts and an electric apparatus using such connecting structure for electric cables. 
     A connecting structure for electric cables, of which improvements are aimed at by the present invention, is configured to electrically connect an electric apparatus unit disposed in a casing and electric cables disposed outside the casing. In one or more embodiments of the present invention, a connecting member used to electrically connect the electric apparatus unit and the electric cables may be disposed to pass through a wall portion of the casing in a thickness direction of the wall portion and not to move with respect of the casing. 
     In this configuration, a portion of the connecting member disposed outside the casing may be utilized for connection of the electric cables. Especially according to the present invention, the electric apparatus unit and the electric cables are electrically connected using the connecting member which does not move with respect to the casing, thereby attaining secure connection between the electric apparatus and the electric cables. 
     The connecting member may comprise a circuit substrate having a connection circuit pattern formed thereon for electrically connecting the electric apparatus unit and the electric cables. In this configuration, the connecting structure for electric cables may preferably further comprise a connecting member attachment configured to be attached to the wall portion of the casing with the circuit substrate of the connecting structure supported thereby. With this configuration, the circuit substrate of the connecting structure may be disposed not to move with respect to the casing simply by attaching the connecting member attachment to the wall portion of the casing. 
     As a typical connecting structure for electric cables, the cores of the electric cables may be connected directly to the connection circuit pattern of the circuit substrate of the connecting structure exposed outside the casing. In this connecting structure, the number of parts used in the connecting structure for electric cables may be reduced. 
     For example, the connecting member attachment may preferably be molded of an electrically insulating resin using the circuit substrate as an insert. This configuration may securely unify the connecting member attachment and the circuit substrate of the connecting structure. 
     A receptacle provided with a connection electrode may be used for connecting the electric cables. In this case, the connecting member attachment may be molded using the receptacle and the circuit substrate of the connecting structure as inserts. An existing receptacle may readily be fixed to the casing by insert molding, thereby eliminating the manufacture of a dedicated receptacle and configuring the connecting structure for electric cables at low costs. 
     An electric apparatus unit may include a circuit substrate having a connection circuit pattern formed thereon. The circuit substrate of the electric apparatus unit is partially opposed to the circuit substrate of the connecting structure for electric cables. In this configuration, the connection circuit pattern of the circuit substrate of the connecting structure and the connection circuit pattern of the circuit substrate of the electric apparatus unit are electrically connected via an electrically connecting component. The use of the electrically connecting component for connection between the connection circuit patterns of the circuit substrates of the electrical apparatus unit and the connecting structure may facilitate and secure the electrical connection between the electric apparatus unit and the electric cables. 
     A plurality of electrically conductive pin members may be used as the electrically connecting component, the electrically conductive pin members each extending in a direction orthogonal with the circuit substrate of the electric apparatus unit and electrically connected to the connection circuit pattern of the circuit substrate of the electric apparatus unit. When the electrically conductive pin members are used, the circuit substrate of the connecting structure may have a through hole formed therein for allowing the electrically conductive pin members to be inserted thereinto, and end portions of the electrically conductive pin members passing through the through hole may be soldered to the connection circuit pattern of the circuit substrate of the connecting structure. Thus, the connection circuit patterns of the circuit substrates of the electric apparatus unit and the connecting structure may readily be connected electrically to each other simply by inserting the electrically conductive pin members into the through hole of the circuit substrate of the connecting structure and then soldering the end portions of the pin members to the connection circuit pattern of the circuit substrate of the connecting structure. Thus, assembling of the electric apparatus may be facilitated. 
     The connecting member may comprise a plurality of electrically conductive terminal members. In this configuration, the connecting member attachment may preferably be attached to the wall portion of the casing with the electrically conductive terminal members supported thereby. Thus, the circuit substrate of the connecting structure may be disposed not to move with respect to the casing simply by attaching the connecting member attachment to the wall portion of the casing. 
     In this configuration, the connecting member attachment is formed with a plurality of support fitting holes for supporting the plurality of electrically conductive terminal members fitted therewith. Thus, the electrically conductive terminal members may be supported simply by fitting the electrically conductive terminal members in the support fitting holes of the connecting member attachment. Preferably, for example, the electrically conductive terminal members may each include a first connecting portion, an intermediate portion, and a second connecting portion. In this configuration, the cores of the electric cables are connected to the first connecting portion. The intermediate portion is continuous with the first connecting portion and extends in a direction crossing the first connecting portion. The second connecting portion is continuous with the intermediate connecting portion, extends in a direction crossing the intermediate portion, and is electrically connected to the electric apparatus unit. Further, the connecting member attachment may preferably be formed of an electrically insulating material, and the support fitting holes of the connecting member attachment may be each constituted from a groove portion in which a base portion of the first connecting portion and the intermediate portion are fitted, and a through hole portion having one end opening in the groove portion and the other end through which the second connecting portion extends out. The use of such support fitting holes may secure the supporting of the electrically conductive terminal members. 
     When the electric apparatus unit includes a circuit substrate having a connection circuit pattern formed thereon and the circuit substrate is partially opposed to the second connecting portions of the electrically conductive terminal members, the connection circuit pattern of the circuit substrate of the electric apparatus unit and the second connecting portions of the electrically conductive terminal members may electrically be connected via electrically connecting components. The electrically connecting components may each include an electrically conductive pin member extending in a direction orthogonal with the circuit substrate of the electric apparatus unit and electrically connected to the connection circuit pattern of the circuit substrate of the electric apparatus unit. The second connecting portions of the electrically conductive pin members each have a through hole formed therein for allowing the electrically conductive pin member to be inserted thereinto, and end portions of the electrically conductive pin members passing through the through holes are soldered to the second connecting portions. The electrically conductive pin members and the connection circuit pattern of the circuit substrate of the electric apparatus unit may readily be connected electrically to each other simply by inserting the electrically conductive pin members into the through holes of the second connecting portions and then soldering the end portions of the electrically conductive pin members to the second connecting portions. Thus, assembling of the electric apparatus may be facilitated. 
     The connecting member may comprise a plurality of lead wire members. The lead wire members are low-priced and are readily transformable, thereby facilitating the connection with the electric apparatus unit. The lead wire attachment and the electric cables may be connected by using a known connecting means such as a connector. When the lead wire members are used as the connecting member, the lead wire members may be used jointly with a connecting member attachment configured to be attached to the wall portion of the casing with the lead wire members supported thereby. In this case, the connecting member attachment is formed with a plurality of support fitting holes for allowing the lead wire members to be pressed thereinto. Further, the connecting member attachment may preferably be configured to liquid tightly block a through hole which is formed in the wall portion of the casing for allowing the lead wire members with the connecting member attachment to pass there through. When such connecting member is used, lead wire members having an arbitrary length may be used. In addition, the connecting member attachment may work to liquid tightly block the through hole through which the lead wire members pass. Likewise, the connecting member attachment may work to prevent an electrically insulating resin from leaking out of the through hole when a molded portion is formed inside the casing by filling the electrically insulating resin into the inside of the casing. The connecting member attachment may connect with a cannon plug including a plurality of terminals which are electrically connect to the lead wire members. The use of such connecting member attachment may readily increase the waterproof performance and electrical insulation of the connecting structure for electric cables. 
     When a molded portion is formed of an electrically insulating resin inside the casing, a portion of the circuit substrate of the connecting structure, which is located inside the casing, may preferably be disposed in the molded portion. This arrangement may securely fix the circuit substrate of the connecting structure, the electrically connecting component, and the circuit substrate of the electric apparatus unit in positions. In other words, the circuit substrate of the connecting structure, the electrically connecting component, and the circuit substrate of the electric apparatus unit may securely be maintained in a fixed positional relationship. 
     An electric apparatus provided with any one of the connecting structures for electric cables as described above for use with power supply cables may appropriately employ a desired connecting structure for electric cables when mass produced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partially cut-away front view of an electric apparatus provided with a connecting structure for electric cables according to an embodiment of the present invention as applied to an electric motor. 
         FIG. 2  is a perspective view of the electric apparatus of  FIG. 1  wherein a rotor, a pair of ball bearings, a non-load-side end bracket, a cover member, and a molded portion are omitted from the illustration. 
         FIG. 3  is a perspective view of a cable connecting unit used in the electric apparatus of  FIG. 1 . 
         FIG. 4  is a perspective view of the cable connecting unit of  FIG. 3  wherein a resin molded portion is omitted from the illustration. 
         FIG. 5  is a partially cut-away front view of an electric apparatus provided with a cable connecting unit according to another embodiment of the present invention. 
         FIG. 6  is a perspective view of the electric apparatus of  FIG. 5  wherein a rotor, a pair of ball bearings, a non-load-side end bracket, and a cover member are omitted from the illustration. 
         FIG. 7  is a perspective view of the cable connecting unit used in the electric apparatus of  FIG. 5 . 
         FIG. 8  is a partially cut-away front view of an electric apparatus provided with a cable connecting unit according to yet another embodiment of the present invention. 
         FIG. 9  is a perspective view of the electric apparatus of  FIG. 8  wherein a rotor, a pair of ball bearings, a non-load-side end bracket, and a cover member are omitted from the illustration. 
         FIG. 10  is a partially cut-away front view of a stator for an electric motor provided with another connecting structure for electric cables according to still another embodiment of the present invention. 
         FIG. 11  is a perspective view of one electrically conductive terminal member used as a connecting member in the embodiment of  FIG. 10 . 
         FIGS. 12A and 12B  are perspective views of a connecting member attachment that supports three electrically conductive terminal members as viewed in different directions. 
         FIGS. 13A and 13B  are perspective views illustrating respectively the connecting member attachment before and after the attachment of three electrically conductive terminal members. 
         FIG. 14  is a half cross sectional view of a cable connecting unit provided with a cannon plug for facilitating and securing the connection of cables according to a further embodiment of the present invention. 
         FIG. 15  is a partially cut-away front view of a stator for an electric apparatus, specifically, an electric motor provided with another connecting structure for electric cables according to yet another embodiment of the present invention. 
         FIGS. 16A and 16B  are perspective views illustrating respectively the connecting member attachment before and after three lead wire members are supported by the connecting member attachment. 
         FIG. 17  is a half cross sectional view of a cable connecting unit provided with a cannon plug for facilitating and securing the connection of cables according to still another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Now, embodiments of the present invention will be described below in detail with reference to the accompanying drawings.  FIG. 1  is a partially cut-away front view of an electric apparatus, specifically, an electric motor provided with a connecting structure for electric cables according to an embodiment of the present invention.  FIG. 2  is a perspective view of the electric motor, wherein a rotor  1  as described later, a pair of ball bearings  5 ,  7 , a non-load-side end bracket  15 , a cover member  17 , and a molded portion  31  are omitted from the illustration. As illustrated in  FIG. 1 , the electric motor of the present embodiment may comprise the rotor  1 , a stator  3 , the pair of ball bearings  5 ,  7 , a casing  13  integrally including a load-side end bracket  9  and a cylindrical portion  11 , the non-load-side end bracket  15 , the cover member  17 , and a cable connecting unit  19 . The rotor  1  includes a shaft  21  and a for magnetic pole  23  fixed on an outer peripheral surface of the shaft  21 . The rotor magnetic pole  23  is constituted from a permanent magnet attachment portion  23   a  fixed on the outer peripheral surface of the shaft  21  and a plurality of permanent magnets  23   b  fixed on an outer peripheral portion of the permanent magnet attachment portion  23   a.    
     The stator  3  includes a stator core  25 , a plurality of winding portions  27 , a circuit substrate  29  for connection, and the molded portion  31 . The stator core  25  is formed of stacked magnetic steel plates. The stator core  25  is disposed radially outwardly of the shaft  21  and includes a cylindrical yoke  33  and a plurality of magnetic pole portions  35  projecting from the yoke  33  toward the shaft  21  to be opposed to the rotor magnetic pole  23 . The winding portions  27  are provided on the stator core  25 . Specifically, the winding portions  27  are wound around the magnetic pole portions  35  via an insulator  37  made of an electrically insulating material. 
     The circuit substrate  29  for connection has a connection circuit pattern formed on an electrically insulated substrate thereof. The circuit substrate  29  is annularly shaped, and is disposed to be opposed to a portion of the insulator  37  that covers an end surface of the stator core  25  as seen in an axial direction. The connection circuit pattern of the circuit substrate  29  is electrically connected to the winding portions  27  via a connecting conductor  30 . A drive circuit for flowing excitation current through the winding portions  27  is provided on the circuit substrate  29 . Electrically conductive pin members  39  are mounted on the circuit substrate  29 , extending in a direction orthogonal with the circuit substrate  29  and electrically connected to the connection circuit pattern of the circuit substrate  29 . The pin members  39  form an electrically connecting component. In the present embodiment, the rotor  1  and the stator  3  constitute a motor unit or an electric apparatus unit disposed inside the casing  3 . 
     The molded portion  31  is formed of a thermosetting and electrically insulating resin. The molded portion  31  is formed inside the casing  13  and covers a part of the stator core  25 , the winding portions  27 , and a part of the cable connecting unit  19 . 
     The load-side end bracket  9  is disposed on one axial side of the shaft  21 . A load is connected to an end portion of the shaft  21  projecting out from the load-side end bracket  9  in the axial direction. The non-load-side end bracket  15  made of metal is disposed on the other axial side of the shaft  21 . 
     The cylindrical portion  11 , the load-side end bracket  9 , and the non-load-side end bracket  15  are formed by aluminum die casting to constitute the casing  13 . The load-side end bracket  9  of the casing  13  has a through hole  9   a  formed in a central portion of the end bracket  9  for allowing the shaft  21  to pass therethrough. An annular concave portion  9   b  is formed around the through hole  9   a  to open toward the non-load-side end bracket  15 . One ball bearing  5  of the paired ball bearings  5 ,  7  is fitted in the annular concave portion  9   b . A portion of the shaft  21  located in one axial side is rotatably supported onto the load-side end bracket  9  via the ball bearing  5 . 
     The stator core  25  is fixed on an inner peripheral portion of the cylindrical portion  11  of the casing  13  which is unitarily formed with the load-side end bracket  9 . The cylindrical portion  11  of the casing  13  has a through hole  11   a  formed in a wall portion thereof to pass the wall portion in a thickness direction of the wall portion. The through hole  11   a  is intended to allow a circuit substrate  43  for connection, which will be described later, to be inserted into the casing  13 . 
     The non-load-side end bracket  15  is in contact with the other end portion of the stator  3  or the other end portion of the molded portion  31 . The non-load-side end bracket includes a bracket body  15   a  extending in a radial direction, an annular inner rib  15   b  unitarily formed with the bracket body and projecting therefrom in the axial direction, and an annular outer rib  15   c  unitarily formed with the bracket body  15   a  and located more outward than the inner rib  15   b  in the radial direction. The bracket body is shaped in a rectangular flange. An inner surface of the inner rib  15   b  is fitted with the other ball bearing of the paired ball bearings  5 ,  7 . Thus, a portion of the shaft  21  located on the other axial side is rotatably supported onto the non-load-side end bracket  15  via the other ball bearing  7   
     The cover member  17  is attached to the non-load-side end bracket  15  and covers the other end portion of the shaft  21  as seen in the axial direction. 
     The cable connecting unit  19  includes a connecting member attachment  41  and the circuit substrate  43  for connection supported by the connecting member attachment  41 , as illustrated in the perspective view of  FIG. 3 . The connecting member attachment  43  is molded using the circuit substrate  43  and a receptacle  45  as inserts. A resin molded portion  47  is formed around the receptacle  45 . The receptacle  45  is a female connector capable of detachably connecting with a connection terminal member C 1  connected to a plurality of electric cables L 1  disposed outside the casing  13 , as illustrated in  FIG. 1 . In the present embodiment, a commercially available receptacle is used as the receptacle  45 . The connecting member attachment  41  thus formed by insert molding allows a commercially available receptacle of any shape and size to be fixed with respect to the casing  13 . As illustrated in  FIG. 4 , the receptacle  45  includes a base  45   a  and a connector portion  45   b . The connector portion  45   b  has a plurality of concave portions  45   c  formed therein for fitting with the connection terminal member C 1 .  FIG. 4  is a perspective view of the cable connecting unit  19  of  FIG. 3  wherein the resin molded portion  47  is omitted from the illustration. 
     The circuit substrate  43  for connection has a connection circuit pattern formed thereon. Specifically, the connection circuit pattern is formed by printing and copper foiling on the circuit substrate  43  having hardness or rigidity. The circuit substrate  43  is shaped substantially in a rectangle. As illustrated in  FIG. 4 , four through hole electrically conductive portions  43   a  are formed in the circuit substrate  4  along one side of the circuit substrate  43  for the purpose of soldering. The four through hole electrically conductive portions  43   a  are connected to four electrodes for soldering, not illustrated but provided on the back surface of the base  45   a  of the receptacle  45  for the purpose of connection. The four soldered electrodes are electrically connected to female connector electrodes provided in the receptacle  45 . The connection circuit pattern, not illustrated, is formed on one of the surfaces of the circuit substrate  43 , and is connected to the four through hole electrically conductive portions  43   a  for performing soldering. The circuit substrate  43  for connection is fixed with respect to the base  45   a  of the receptacle  45  so as to extend in a direction orthogonal with an extending direction of the base  45   a . The connection circuit pattern of the circuit substrate  43  is electrically connected to a plurality of through hole electrically conductive portions provided in the concave portions  45   c  of the receptacle  45 . 
     As illustrated in  FIG. 1 , the circuit substrate  43  for connection is disposed such that a portion of the circuit substrate  43 , which passes through the through hole formed through the wall portion of the cylindrical portion  11  of the casing  13  in the thickness direction and is then located inside the casing, is disposed in the molded portion  31 . Then, the circuit substrate  43  is disposed to be opposed to the circuit substrate  29  and not to move with respect to the casing  13 . In other words, the circuit substrate is partially opposed to the circuit substrate  43 . As illustrated in  FIG. 4 , the circuit substrate  43  has four through holes  43   b  formed therein. As illustrated in  FIG. 1 , the electrically conductive pin members  39  attached to the circuit substrate  29  are inserted into the four through holes  43   b .  FIG. 1  is a half cross sectional view showing one electrically conductive pin members  39  inserted in one of the through holes  43   b . An end portion of each electrically conductive pin member passing through the through hole  43   b  is soldered to the connection circuit pattern of the circuit substrate  43 . Thus, the connection circuit pattern of the circuit substrate  43  and the connection circuit pattern of the circuit substrate  29  are electrically connected via the electrically conductive pin members  39 . 
     As illustrated in  FIG. 3 , the resin molded portion  47  is formed to surround the base  45   a  of the receptacle  45  by insert molding using the receptacle  45  and the circuit substrate  43  as inserts. The resin molded portion  47  has a through hole  47   a  formed at each of four corners. As illustrated in  FIG. 2 , the connecting member attachment  41  is attached to the wall portion of the cylindrical portion  11  of the casing  13  with the circuit substrate  43  supported thereby. Specifically, the connecting member attachment  41  is attached to the wall portion with four screws  49  which are screwed into screw holes formed in the cylindrical portion  11  of the casing  13  after passing through the four through holes  47   a.    
     In the present embodiment, the circuit substrate  43  is soldered to the base  43   a  of the receptacle  43  as illustrated in  FIG. 4 , and then the resin molded portion is molded using the circuit substrate  43  and the receptacle  45  as inserts to obtain the cable connecting unit  19  as illustrated in  FIG. 3 . 
     In the present embodiment, the cable connecting unit  19  is attached to the casing  13 . First, the stator core  25  provided with the circuit substrate  29  for connection is fixed in the cylindrical portion  11  of the casing  13 . Next, the circuit substrate  43  is inserted into the casing  13  through the through hole  11   a  of the casing  13  such that the electrically conductive pin members  39  are spaced away from the circuit substrate  43  of the cable connecting unit  19 . Then, the circuit substrate  43  is moved in such direction that a surface of the circuit substrate  43 , which faces the circuit substrate  29 , is brought closer to the circuit substrate  29  and then the electrically conductive members  39  are inserted into the through holes  43   b  of the circuit substrate  43 . An end portion of each electrically conductive pin member  39  is slightly projected from the back surface of the circuit substrate  43 . The through hole  11   a  has an enough size to allow such movement of the circuit substrate  43 . Next, as illustrated in  FIG. 2 , the connecting member attachment  41  is attached to the wall portion of the cylindrical portion  11  of the casing  13  with the four screws  49 . Then, the end portions of the electrically conductive pin members  39  are soldered to the connection circuit pattern of the circuit substrate  43 . Finally, the molded portion  31  is formed of an electrically insulating resin inside the casing  13 . Thus, the attachment of the cable connecting unit  19  is completed. 
     The connecting structure for electric cables of the present embodiment allows connection of the electric cables L 1  via the receptacle  45  by utilizing a portion of the circuit substrate  43  disposed outside the casing  13 . The stator  3  of the electric apparatus unit is electrically connected to the electric cables L 1  using the circuit substrate  43  for connection that does not move with respect to the casing  13 , thereby securing the connection between the stator  3  and the electric cables L 1 . 
       FIG. 5  is a partially cut-away front view of an electric apparatus, specifically, an electric motor provided with a connecting structure for electric cables according to another embodiment of the present invention.  FIG. 6  is a perspective view of the electric motor wherein a rotor  101 , a pair of ball bearings  105 ,  107 , a non-load-side end bracket  115 , and a cover member  117  are omitted from the illustration.  FIG. 7  is a perspective view of a cable connecting unit  119  used in the electric motor of  FIG. 5 . The configuration of the electric motor illustrated in  FIGS. 5 to 7  except for a cable connecting unit is the same as that of the electric motor illustrated in  FIGS. 1 to 4 . Out of the parts or members illustrated in  FIGS. 5 to 7 , those parts or members structurally similar to those illustrated in  FIGS. 1 to 4  are allocated reference numerals or signs obtained by adding 100 to the reference numerals or signs shown in  FIGS. 1 and 2 , and accordingly the descriptions thereof are omitted. 
     As particularly illustrated in  FIG. 7 , the cable connecting unit  119  used in the present embodiment includes a connecting member attachment  141  and a circuit substrate  143  for connection supported by the connecting member attachment  141 . The connecting member attachment  141  is molded of an electrically insulating resin using the circuit substrate  143  as an insert. The connecting member attachment  141  is provided with a cap  151  for covering the connecting member attachment  141 . Refer to  FIGS. 5 and 6 . The connecting member attachment  141  has a through hole  141   a  at each of four corners. The positional relationship of the four through holes  141   a  with the circuit substrate  143  for connection is the same as that of the four through holes  47   a  formed in the resin molded portion  41  illustrated in  FIG. 3  with the circuit substrate  43  for connection. As illustrated in  FIG. 6 , the connecting member attachment  141  is attached to a wall portion of a cylindrical portion  111  of a casing  113  together with the cap  151  with the circuit substrate  143  supported by the connecting member attachment  141 . Specifically, the connecting member attachment  141  is attached to the wall portion with four screws  149  which are screwed into screw holes formed in the cylindrical portion  111  of the casing  113  after passing through the four through holes  141   a.    
     The circuit substrate  143  has the same structure as that of the circuit substrate  43  illustrated in  FIG. 4 . End portions of electrically conductive pin members  139  passing through through holes  143   b  are soldered to the connection circuit pattern of the circuit substrate  143 . In the present embodiment, as illustrated in  FIG. 5 , the cores of four electric cables L 2  are directly connected to the connection circuit pattern of the circuit substrate  143  using four through hole electrically conductive portions  143   a  formed in the circuit substrate  143  exposed outside the casing  113 . 
     The connecting structure for electric cables of the present embodiment allows direct connection of the cores of the electric cables L 2  to the connection circuit pattern of the circuit substrate  143 , thereby reducing the number of parts or components used in the connecting structure for electric cables. 
       FIG. 8  is a partially cut-away front view of an electric apparatus, specifically, an electric motor provided with a connecting structure for electric cables according to yet another embodiment of the present invention.  FIG. 9  is a perspective view of the electric motor wherein a rotor  201 , a pair of ball bearings  205 ,  207 , a non-load-side end bracket  215 , and a cover member  217  are omitted from the illustration.  FIG. 7  is a perspective view of a cable connecting unit  119  used in the electric motor of  FIG. 5 . The configuration of the electric motor illustrated in  FIGS. 8 and 9  except for a cable connecting unit is the same as that of the electric motor illustrated in  FIGS. 1 to 4 . Out of the parts or members illustrated in  FIGS. 8 and 9 , those parts or members structurally similar to those illustrated in  FIGS. 1 to 4  are allocated reference numerals or signs obtained by adding 200 to the reference numerals or signs shown in  FIGS. 1 and 2 , and accordingly the descriptions thereof are omitted. 
     As illustrated in  FIG. 8 , the cable connecting unit  219  used in the present embodiment includes a connecting member attachment  241  and a circuit substrate  243  for connection supported by the connecting member attachment  241 . The connecting member attachment  241  includes connector or so-called cannon plug and lead wires  240 . The connector or cannon plug is detachably connected to a terminal member C 3  for connection connected with the electric cables L 3  disposed outside the casing  213 . The connecting member attachment  241  includes a cylindrical base portion  241   b  and a connector portion  241   c . The base cylindrical portion  241   b  has a through hole formed at each of four corners. As illustrated in  FIG. 9 , the connecting member attachment  241  is attached to a wall portion of a cylindrical portion  211  of a casing  213  with the circuit substrate  243  supported thereby. Specifically, the connecting member attachment  241  is attached to the wall portion with four screws  249  which are screwed into screw holes formed in the cylindrical portion  211  of the casing  213  after passing through the through holes formed in the base  241   b.    
     As illustrated in  FIG. 9 , the connector portion  241   c  has a concave portion  241   e  formed to open upward. Seven terminals  241   f  are formed in the concave portion  241   e  to be fitted with the terminal member C 3  for connection as illustrated in  FIG. 8 . 
     The circuit substrate  243  has the same structure as that of the circuit substrate  43  illustrated in  FIG. 4 . End portions of electrically conductive pin members  239  passing through through holes  243   b  are soldered to the connection circuit pattern of the circuit substrate  243 . In the present embodiment, as illustrated in  FIG. 8 , the cores of lead wires  240 , which are electrically connected to four terminals actually used out of seven terminals  241   f , are connected to the connection circuit pattern of the circuit substrate  243  via four through hole electrically conductive portions provided in the circuit substrate  243  disposed outside the casing  213 . Thus, the connecting member attachment  241  of the present embodiment supports the circuit substrate  243  for connection by means of the lead wires  240 . 
       FIG. 10  is a partially cut-away front view of a stator for an electric apparatus, specifically, an electric motor provided with another connecting structure for electric cables according to still another embodiment of the present invention.  FIG. 11  is a perspective view of one electrically conductive terminal member  343  used as a connecting member in the present embodiment.  FIGS. 12A and 12B  are perspective views of a connecting member attachment  341  that supports three electrically conductive terminal members  343  as viewed in different directions.  FIGS. 13A and 13B  are perspective views illustrating respectively the connecting member attachment  341  before and after the attachment of the three electrically conductive terminal members  343 . The configuration of the stator for an electric motor illustrated in  FIG. 10  except for a cable connecting unit is the same as that of the electric motor illustrated in  FIGS. 1 to 4 . Out of the parts or members illustrated in  FIG. 10 , those parts or members structurally similar to those illustrated in  FIGS. 1 to 4  are allocated reference numerals or signs obtained by adding 300 to the reference numerals or signs shown in  FIGS. 1 and 2 , and accordingly the descriptions thereof are omitted. 
     As illustrated in  FIGS. 10 and 13 , the cable connecting unit  319  includes a connecting member attachment  341  and three electrically conductive terminal members  343  supported by the connecting member attachment  341 . As illustrated in  FIG. 11 , the electrically conductive terminal members  343  each include a first connecting portion  343 A, an intermediate portion  343 B, and a second connecting portion  343 C. In this configuration, the core of each electric cable is connected to the first connecting portion  343 A. The intermediate portion  343 B is continuous with the first connecting portion  343 A and extends in a direction crossing the first connecting portion  343 A. The second connecting portion  343 C is continuous with the intermediate connecting portion  343 B, extends in a direction crossing the intermediate portion  343 B, and is electrically connected to an electrically conductive pin member  339  leading to a drive circuit disposed in the stator. A recess or slit portion  343 E is formed in the first connecting portion  343 A. The cores of the electric cables are fitted in recess or slit portion  343 E and soldered thereto. Likewise, a recess or slit portion  343 F formed with a through hole is provided in the second connecting portion  343 C. The electrically conductive pin members  339  are fitted in the through holes of the recess or slit portions  343 F and soldered thereto. 
     As illustrated in  FIG. 12 , the connecting member attachment  341  has three support fitting holes  341 A formed for supporting three electrically conductive terminal members  343  with the three electrically conductive terminal members fitted with the support fitting holes  341 A. The connecting member attachment  341  is formed of an electrically insulating material such as fluororubber. The support fitting holes  341 A each include a groove portion  341 B in which a base portion of the first connecting portion  343 A and the intermediate portion  343 B of the electrically conductive terminal member  343  are fitted and a through hole portion  341 C having one end opening in the groove portion  341 B and allowing the second connecting portion  343 C to extend out therethrough. The connecting member attachment  341  unitarily include a projecting portion  341 D through which the through hole portions  341 C pass. The projecting portion  341 D is fitted in the through hole  311   a  formed in the cylindrical portion  311  of the casing  313 . When forming a molded portion  331 , as illustrated in  FIG. 10 , the stator is placed inside a mold with the connecting member attachment  341  being pressed onto the cylindrical portion  311  of the casing  313  with a metallic pressing tool  311   a , and then the stator is molded by filling a resin into the stator. The use of the connecting member attachment thus obtained allows the supporting of a plurality of electrically conductive terminal members  343  simply by fitting the electrically conductive terminal members  343  in the support fitting holes  341 A. 
     When the stator of the present embodiment includes a circuit substrate  329  for connection having a connection circuit pattern and partially opposed to the second connecting portions  343 C of the three electrically conductive terminal members  343  as illustrated in  FIG. 10 , the connection circuit patter of the circuit substrate  329  and the second connecting portions  343 C of the three electrically conductive terminal members  343  are electrically connected to each other via electrically conductive connecting components, specifically, electrically conductive pin members  339 . Thus, the electrically conductive terminal members  343  and the connection circuit pattern of the circuit substrate  329  may electrically be connected simply by inserting the electrically conductive pin members  339  into through holes formed in the recess or slit portion  343 F of the second connection portion  343 , and then soldering end portions of the electrically conductive pin members  339  to the second connecting portion  343 C. Alternatively, the cores of the electric cable may directly be soldered to the first connecting portions  343 A of the electrically conductive terminal members  343  in a state shown in  FIG. 10 . 
       FIG. 14  is a half cross sectional view of a cable connecting unit  419  provided with a cannon plug  442  for facilitating and securing the connection of electric cables according to a further embodiment of the present invention. In  FIG. 14 , those parts or members structurally similar to those illustrated in  FIGS. 1 to 4  are allocated reference numerals or signs obtained by adding 400 to the reference numerals or signs shown in  FIGS. 1 and 2 , and accordingly the descriptions thereof are omitted. The stator of the present embodiment is provided with the cable connecting unit which has substantially the same structure as the cable connecting unit  319  of the embodiment shown in  FIG. 10  except that the cannon plug is fixed to the cable connecting unit  319  in the present embodiment. A plurality of terminals, not illustrated, provided in the cannon plug  442  are connected to a plurality of electrically conductive terminal members  443  by soldering or swaging the cores of lead wires  440  to the electrically conductive terminal members  443 . Then, a cylindrical base  442   b  of the cannon plug  442  is attached on a connecting member attachment  441  by some means such as ultrasonic adhesion. 
       FIG. 15  is a partially cut-away front view of a stator for an electric apparatus, specifically, an electric motor provided with another connecting structure for electric cables according to yet another embodiment of the present invention.  FIGS. 16A and 16B  are perspective views illustrating respectively the connecting member attachment before and after three lead wire members  543  are supported by a connecting member attachment  541 . The configuration of the stator for an electric motor illustrated in  FIG. 15  except for a cable connecting unit is the same as that of the electric motor illustrated in  FIGS. 1 to 4 . Out of the parts or members illustrated in  FIG. 15 , those parts or members structurally similar to those illustrated in  FIGS. 1 to 4  are allocated reference numerals or signs obtained by adding 500 to the reference numerals or signs shown in  FIGS. 1 and 2 , and accordingly the descriptions thereof are omitted. 
     As particularly illustrated in  FIGS. 15 and 16 , a cable connecting unit  519  used in the present embodiment includes the connecting member attachment  541  and three lead wire members  543  supported by the connecting member attachment  541 . As illustrated in  FIG. 16 , the lead wire members  542  are each formed of an insulating coated electric cable having one end portion  543 A connected to the core of an electric cable and the other end portion  543 B connected to a circuit substrate  529  for connection provided on a side of the stator. 
     As illustrated in  FIG. 16 , the connecting member attachment  541  has three support fitting holes  541 A for supporting the three lead wire members  543  with the three lead wire members  543  supported thereby. The connecting member attachment  541  is formed of an electrically insulating material such as fluororubber. Insulating coated portions of the three lead wire members  543  are pressed into the support fitting holes  541 A. Alternatively, the connecting member attachment  541  may unitarily include a projecting portion  541 D through which the support fitting holes  541 A are formed. The projecting portion  541 D is fitted into a through hole  511   a  formed in a cylindrical portion  511  of a casing  513 . When forming a molded portion  531 , the connection member attachment  541  is pressed onto the cylindrical portion  511  of the casing  513  with a pressing tool  550  illustrated in  FIG. 15 . Then, the stator is placed in a mold with the connecting member attachment pressed onto the cylindrical portion  511 , and a resin is filled into the stator. The use of the connecting member attachment  541  thus obtained allows the support of the lead wire members  543  simply by fitting the lead wire members  543  in the support fitting holes  541 A. 
       FIG. 17  is a half cross sectional view of a cable connecting unit  619  provided with a cannon plug  642  for facilitating and securing the connection of cables according to still another embodiment of the present invention. In  FIG. 17 , those parts or members structurally similar to those illustrated in  FIGS. 1 to 4  are allocated reference numerals or signs obtained by adding 600 to the reference numerals or signs shown in  FIGS. 1 and 2 , and accordingly the descriptions thereof are omitted. The stator of the present embodiment is provided with the cable connecting unit which has substantially the same structure as the cable connecting unit  519  of the embodiment shown in  FIG. 15  except that the cannon plug  642  is fixed to the cable connecting unit in the present embodiment. A plurality of terminals, not illustrated, provided in the cannon plug  642  are connected to the cores of a plurality of lead wires  640 . The core materials of the lead wires  640  and the core materials of lead wire members  643  are connected by using a pressure bonding sleeve  644 . A cylindrical base  642   b  of the cannon plug  642  is attached onto a connecting member attachment  641  by some means such as ultrasonic adhesion. 
     According to the present invention, a connecting member, which is disposed not to move with respect to a casing, is used to electrically connect an electric apparatus unit and a plurality of electric cables, thereby securing the connection between the electric apparatus unit and the electric cables with a low-priced connecting structure. Further, a connecting member attachment may be molded using a commercially available receptacle as an insert. 
     While certain features of the invention have been described with reference to example embodiments, the description is not intended to be construed in a limiting sense. Various modifications of the example embodiments, as well as other embodiments of the invention, which are apparent to persons skilled in the art to which the invention pertains, are deemed to lie within the spirit and scope of the invention.