Abstract:
An electrical machine having a plurality of pole pieces surrounded by bobbins and upon which individual coil windings are formed. The bobbins are formed by a insulating material in which are embedded electrical connectors that have terminal ends that afford connection to the coil windings and to an external connection for either deriving electrical power in the case the machine operates as a generator or receiving power in the event the device operates as a motor. In addition the individual coils are arranged in groups that can be connected together through internal connections in such a way to provide different electrical outputs without internal taps or redesign of the machine. Thus, cost is reduced and at the same time the device is more compact and has greater efficiency and wider utility.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a wiring arrangement for a rotating electrical machine and more particularly to an improved arrangement for forming the coil windings and electrical connections therefore to offer more flexibility, compactness, efficiency and lower cost. 
     In many forms of AC generators such as magneto generator, there is provided a stator that has a plurality of stator cores wound around individual cores. Generally, these cores consist of a number of poles and frequently the poles are wired so as to provide different electrical output terminals. For example, in many applications particularly in connection with motor vehicles driven by internal combustion engines, a plurality of stator coils are connected in series and divided into groups with intermediate taps so that the electrical power generated by respective stator coil groups can be used independently of each other. For example, it is frequently the practice to use one group having twice as many coils as the other group with one group operating electrical accessories such as light bulbs or the like that operate on 12 volts and the other group being utilized to charge the battery and provide an output of 6 volts. The ignition circuit of the engine uses the battery charge from the respective stator coil group. 
     However, the application of these principals and the numbers of coils utilized can vary significantly depending upon the particular application. The conventional structures employed for forming these coil windings and grouping requires individual taps and frequently soldered connections to provide the desired connections. Thus, to change from one application to another can require a completely different machine, which requires additional dyes and winding machines for winding the coils. In addition, the coils are wound around a non-conductive bobbin, which is generally formed integrally from an insulating resin, and the change in configuration requires changes in the forming dyes for the bobbin. 
     It is, therefore, a principal object to this invention to provide an improved stator for an AC generator wherein the changing of positions of intermediate taps to provide different coil groupings can be simplified. 
     It is a further object to this invention to provide a bobbin assembly for cooperation with the stator coil wherein the bobbin assembly provides a number of electrical connection terminals that can receive suitable conductors for changing the coil grouping without necessitating total reconstruction of the configuration of the winding. 
     SUMMARY OF THE INVENTION 
     This invention is adapted to be embodied in a wiring arrangement for a rotating machine comprised of a plurality of coils each wound on the pole teeth of a core through a bobbin. The bobbin has portions surrounding the pole teeth of the core. A plurality of internal electrical terminal connectors is formed on the bobbin. Coil winding ends from selected of the coils form terminals in selected of the internal electrical terminal connectors. An internal tap block is insertable in selected of the electrical terminal connectors for connecting the coil ends of two different stator coils, so that the distribution ratio of the stator coils can be varied when the internal electrical terminal in which the intermediate tap block inserted, is changed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross sectional view taken through a rotating electrical machine constructed in accordance with an embodiment of the invention and showing, in this embodiment, the stator in cross-section and solid lines with the remaining components of the machine being shown in phantom. This view is taken generally along the line  1 - 0 - 5  of FIG.  4 . 
     FIG. 2 is a front view of the stator. 
     FIG. 3 is a perspective view of the stator core. 
     FIG. 4 is a front view of the stator coils showing the winding direction thereof. 
     FIG. 5 is an enlarged cross sectional view taken along the line O- 5  of FIG.  4 . 
     FIG. 6 is an enlarged cross section along line O- 6  of FIG.  4 . 
     FIG. 7 is a front view of one of the bobbin halves. 
     FIG. 8 is a view looking in the same direction as FIG. 7 showing the arrangement of the inserted wiring conductors in solid lines with the body of the bobbin half shown in phantom. 
     FIG. 9 is an exploded perspective view of the bobbin half shown in FIGS. 7 and 8 and showing the relation to the associated electrical connectors or terminals and the other bobbin half that is shown broken away. 
     FIG. 10 is an exploded front view of the external connections and associated electrical connector shown in FIG.  9 . 
     FIG. 11 is a wiring diagram showing two different ways the coil ends may be connected by internal connectors to provide two different coil groupings with the same basic stator construction. 
     FIG. 12 is a wiring diagram in part similar to FIG. 11 showing another embodiment and how it provides two different ways the coil ends may be connected by internal connectors to provide two different coil groupings with the same basic stator construction. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring first to FIG. 1, a rotating electrical AC generator constructed in accordance with an embodiment of the invention is identified generally by the reference numeral  21 . This invention deals primarily with the coil windings and terminal connections of this generator  21 , which is embodied in a stator  22  having a plurality, namely  12 , of pole pieces or cores  23  and associated bobbins of a bobbin assembly  24  on which coil windings  25  are wound, in a manner to be described. 
     The stator  22  is fixed against rotation in any suitable manner for example to the crankcase of an associated internal combustion engine. The stator  22  cooperates with a rotating cup-shape member  26  that carries a plurality of circumferentially spaced permanent magnets  27 . This cup-shape member  26  is affixed for rotation with a shaft  28  such as the crankshaft of the associated internal combustion engine that rotates in the associated crankcase. 
     As noted, the rotating machine  21  comprises an electrical generator wherein a voltage is induced in the coil windings  25  upon rotation of the magnets  27  to provide electrical current output. Although the invention is described in conjunction with a stator, certain facets of the invention may also be employed where the rotor carries the coil windings. 
     From the description of the problem of the prior art contained in the “Background Of The Invention” section of the specification, it should be apparent that the invention deals primarily with the manner in which the windings  25  are associated with the cores  23  and the electrical connections therebetween. The male electrical connector for the external electrical connection appears in FIG.  1  and is identified generally by the reference numeral  29 . This male electrical connector  29  cooperates with a female external terminal or connector  31  formed in a manner to be described on the stator  22  around an annular opening  32  formed therein, which a portion of the shaft  28  passes. 
     Referring now primarily to FIG. 3, the core  23  is formed of a laminated construction consisting of silicon or carbon steel plates laminated with insulating layers. This forms the plurality of cores or pole pieces  23 , certain of which are numbered alphabetically, that extend outwardly from a hub portion  34 . Each of the pole pieces  23  has an enlarged headed portion. 
     As may be best seen in the cross-sectional views of FIGS. 5 and 6, the bobbin assembly, indicated generally by the reference numeral  24  is associated with the cores  23  and is formed from a pair of mating pieces or halves  24 A and  24 B. The bobbin halves  24 A and  24 B are snugly received around the pole pieces  23  and each has a pair of flanges  36  and  37  around which the individual coil windings  25  are wound in a manner which will be described. The bobbin halves  24 A and  24 B are made from a suitable insulating resin by injection molding. 
     During this molding process, a number of conductors, which may be formed from stamped metallic pieces, are embedded in one or both of the bobbin halves  24 A and  24 B. In the illustrated embodiment, all of these conductors are mounted in a side enlargement of the bobbin half  24 A and these conductors appear best in FIG.  8 . 
     The conductors, indicated generally by the reference numerals  39 ,  41  and  42 , have common external, output terminals that lie in side by side relationship as best seen in FIG.  3  and which form terminal ends Y, B and W, designated as color coding of the individual conductors  39 ,  41  and  42 , respectively. The conductors  39 ,  41  and  42  are formed preferably as stamped blanks of a highly conductive material such as copper. Opposite ends of these conductors  39 ,  41  and  42  are associated with certain of the coil windings  25  in a manner to be described so as to simplify the connections thereto and the entire electrical structure and to avoid the necessity of having soldered connections. 
     The external female communication terminal  31  is formed integrally with the bobbin half  24 A and encircles the terminal ends Y, B and W of the individual conductors  39 ,  41  and  42  so as to receive the connector  29  when pressed together in a radial direction and form the desired electrical connections. This construction appears best in FIGS. 1,  2 ,  9  and  10 . 
     As may be seen, particularly from these latter two figures, the bobbin half  24 A is formed with a pair of openings  43  that receive tabs  44  formed on the external male connector  29 . This provides a snap together connection being made as seen in these figures. Wires Y, B and W are carried by the connector  29  and cooperate with the terminal ends of the corresponding designation. Thus, electrically power can be extracted through these conductors. This external female terminal  31  is formed adjacent a pole piece indicated at  23 A, the first pole counting in a clockwise direction. 
     The conductor  41  extends from its terminal end B in a clockwise direction around the bobbin half  24 A and terminates adjacent the fifth pole ( 23 B) counting in a clockwise direction from the pole  23 A at a terminal  45 . This terminal  45  extends up to the base of the magnetic pole  23 B and terminates in a further female electrical connector  46  formed in the bobbin half  24 A and integrally with it. In a similar manner, the conductor  42  extends circumferentially around from the first pole  23 A past the fifth pole  23 B to the sixth pole  23 C where it forms a terminal end  47 . This terminal end  47  terminates in a further female electrical connector  48  formed integrally with the bobbin half  24 A. 
     Finally, the conductor  39  extends in a counter clockwise direction from the terminal end Y to a first terminal end  49  formed adjacent the tenth pole  23 D. This terminal end  49  extends to the base of the tenth pole  23 D and terminates in a female internal electrical connector  51  formed by the bobbin half  24 A. The conductor  39  extends past the first terminal end  49  to a further female internal electrical connector  52  where it terminates at a terminal  53 . 
     Referring now primarily to FIG. 4, in the illustrated embodiment the twelve poles including the already mentioned poles  23 A,  23 B,  23 C, and  23  D and their associated windings  25  are formed in three groups, the first consisting of a winding N 1  which forms three coils begins at the terminal end  47  where it is connected by means of inserting it into an opening formed in a tip of the terminal end  47  thus avoiding the necessity for soldering. 
     This winding is then wound around the sixth pole  23 C and specifically the portion of the bobbin  24  that is associated with it and then without interruption wound around the next two poles terminating at the eighth pole  23 E and terminates at a conductor terminal  54  found at the base of this pole in the internal electrical connector  52 . These ends are seen in FIGS. 4 and 11. 
     In a similar manner, a second winding N 2  begins at a terminal  55  formed in the internal electrical connector  51  and is wound around the tenth pole  23 D and more specifically its bobbin and the succeeding seven poles traveling in the clockwise direction to terminate at the pole  23 B where it terminates in the electrical connector  46  and is connected to the terminal  45  of the conductor  42  (Black). 
     As has been noted, the first winding N 1  consists of three coils and the second winding N 2  consists of eight coils beginning at the coil  25 D and ending at the coil  25 B. This leaves a further coil winding which is formed around the pole  23 F and which is refereed to as the coil  25 F. This coil extends between a pair of terminals  56  and  57  that are formed in the internal female connectors  52  and  51 , respectively. Thus, there are three coil groups consisting of the coils formed by the windings N 1  and N 2  and the winding group consisting of the single coil  25 D. 
     This is shown in FIG.  11  and this figure shows how the system can be utilized with two different types of internal connectors of the male type so as to provide a coil grouping consisting of either nine coils and three coils (output ratio of 9/3) or eight coils and four coils (output ratio of 8/4) depending upon the connector that is used. The first connector arrangement (9/3 ratio) appears along the line A of FIG. 11 wherein a first connector  58  is provided with a pair of prongs and a conductor  59  which is inserted into the female connector  51  so as to establish a connection between the terminals  55  and  56  and thus place the coil  25 D in with the coil grouping of the winding N 2  to form nine coil windings in this group. 
     In a similar manner, a further conductor  61  having three female sections all connected by a common conductor or bar  62  is inserted into the internal connector  52  so as to connect the terminals  57 ,  53  and  55  all together and provide the desired coil groupings. 
     If the connectors  58  and  61  are reversed as shown in FIG. 11 in the B part of the view, then there is a different coil grouping consisting of the eight coil grouping of the second winding and the four winding group of the first winding and the coil  25 D so as to provide the opportunity of having a different split in the outputs while maintaining the same overall construction. 
     The internal connectors  46  and  48  are closed by male tap blocks  63  that establish the electrical connections between the coil ends  25 B and  25 C and their respective conductor terminals  45  and  47 . 
     Thus, merely by changing the internal male connections, it is possible to vary the output sources possible. Thus, it should be seen with this embodiment it is very simple to change the ratio of the outputs of the generator merely by utilizing two internal connectors having internal circuits that either connector or bypass the coil ends with each other. 
     FIG. 12 shows another embodiment that achieves this same result while minimizing the number of different types of internal connectors that can be utilized. Because the only difference between this embodiment and that already described is the way in which the internal connectors  51  and  52  are wired, only a figure corresponding to FIG. 11 is believed to be necessary for those skilled in the art to practice this embodiment of the invention. 
     FIG. 12 is such a figure and because of its similarity to the embodiments previously described, many of the components are identified by the same reference numerals and will only be described further to permit those skilled in the art to understand how this embodiment operates and can be utilized. 
     In this embodiment, in the internal connector  51  an internal wiring consisting of a conductor  71  bridges the terminals  55  and  56  and thus provides a connection between the one end of the coil winding  25 D and the windings of winding N 2  consisting of the eight coil grouping. In a similar manner, the internal connector  52  has a conductor  72  that interconnects its terminals  57  and  54  and thus provides a connection between the other end of the coil winding  25 D and the winding N 1  of the three-coil grouping. 
     A single internal female connector  73  is formed with a pair of joined terminals connected by a conductor  74 . If this is placed in the connector  52  it will bridge the Y terminal  53  with the grouped coil winding and thus form a three coil output section. Thus, the remaining coils are all connected together so as to provide the 9 to 3 output ratio. 
     On the other hand, if the internal connector  73  is placed on the terminal  51  and bridges the terminals  49  and  56  therein, then the coil  25 D is joined with the coil winding N 1  and the remaining coils operate alone to provide an 8 to 4 ratio. 
     Thus, from the foregoing description it should be readily apparent that the described embodiments of the invention provide a very effective winding for a group of coils that permits the coils to be connected in various grouping arrangements through the use of internal connectors and without total redesign of the assembly. Of course, the foregoing description is that of a preferred embodiment of the invention and various changes and modification can be made without departing from the spirit and scope of the invention, as defined by the appended claims.