Abstract:
A dynamoelectric machine insulator includes, a body having a plurality of holes therethrough at least some of the plurality of holes being receptive of a lead such that a lead extending through each of the plurality of holes is electrically isolated from a lead extending through each of the other of the plurality of holes, and at least one channel in the body extending arcuately along a perimetrical extent of the body. The at least one channel configured and dimensioned to insulate at least one lead routed therein.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. provisional application, 60/851,576, filed Oct. 13, 2006, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Some dynamoelectric machines such as alternators, for example, have stators with leads that protrude axially therefrom. The leads are terminated at the end of the stator from which they extend. Some leads require routing circumferentially along an end of the stator before reaching their point of termination. Varnish is applied to the leads to attach them to and insulate them from end turns of windings of the stator as well as from one another. During operation of the dynamoelectric machine, however, if the varnish has not bonded the leads adequately to the end turns, vibration can cause the leads to become loose. Such looseness permits the leads to chafe against other components moving in relation to the leads possibly causing failure of insulation and electrical shorting. Additionally, the lead routings can block cooling airflow from passing through the space between the stator and an endplate of the slip ring end (SRE) housing causing inadequate cooling of the dynamoelectric machine. 
         [0003]    Accordingly, alternate lead routings and points of termination of leads that overcome the above mentioned shortcomings would be desirable in the art. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0004]    Disclosed herein is a dynamoelectric machine insulator. The insulator includes, a body having a plurality of holes therethrough at least some of the plurality of holes being receptive of a lead such that a lead extending through each of the plurality of holes is electrically isolated from a lead extending through each of the other of the plurality of holes, and at least one channel in the body extending arcuately along a perimetrical extent of the body. The at least one channel configured and dimensioned to insulate at least one lead routed therein. 
         [0005]    Further disclosed herein is a method of insulating leads in a dynamoelectric machine. The method includes, feeding a plurality of leads of a stator axially through a plurality of holes in an insulator such that each hole has no more than one lead therein, and routing a plurality of leads within a plurality of channels in the insulator extending arcuately along a perimetrical extent of the insulator. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
           [0007]      FIG. 1  depicts a partial perspective view of an alternator showing an insulator disclosed herein; 
           [0008]      FIG. 2  depicts a partial perspective view of the alternator of  FIG. 1  with the SRE cover removed; 
           [0009]      FIG. 3  depicts a plan view of the alternator of  FIG. 2 , 
           [0010]      FIG. 4  depicts a partial perspective view of an insulator shown in  FIG. 2 , and 
           [0011]      FIG. 5  depicts a partial side view of the alternator of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0012]    A detailed description of several embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
         [0013]    Referring to  FIG. 1  a partial perspective view of a dynamoelectric machine, including an embodiment of the insulator disclosed herein, is illustrated generally at  10 . In this embodiment the dynamoelectric machine  10  is an alternator that has a slip ring end (SRE) housing end plate  14  and a SRE cover  18 . The SRE cover  18  is made from a nonconductive material such as polymer resin, for example, and is attached to the SRE housing end plate  14 , which can be made of a conductive material such as aluminum, for example. Several conductive leads  22  with optional rectangular cross sections can be seen through cooling windows  30  in a perimetrical surface  34  of the SRE housing end plate  14 . The number of leads  22  may vary depending upon the number of phases of the dynamoelectric machine, for example, and the leads  22  can be either neutral or positive. A portion of all of the leads  22  may extend substantially axially from an axial end of a stator (not shown). 
         [0014]    Referring to  FIG. 2  a partial perspective view of the alternator  10  of  FIG. 1  is shown with the SRE cover  18  removed. An insulator  38 , made of a nonconductive material such as plastic, for example, has a plurality of holes  42  through which the leads  22  extend. Termination of the leads  22  is completed on a side of the insulator  38  opposite a side on which the stator is located. The termination can be by methods such as welding, soldering or crimping within clips  20 , for example, as is disclosed herein. Thus, the leads  22  extend substantially parallel to an axis of the stator through the holes  42  as best shown in  FIG. 5 , thereby allowing cooling air to flow around the leads  22 , between the stator and the insulator  38 , and out through the cooling windows  30  in the SRE housing end plate  14 . 
         [0015]    Referring to  FIG. 3 , each of the holes  42  in the insulator  38 , has at least one lead  22  extending therethrough. In this embodiment the four central holes  42  each have a pair of leads  22  extending therethrough while the outer two holes  42 A and  42 B each have a single lead  22 A and  22 B extending therethrough respectively. There are two additional holes  42 C and  42 D that extend axially through the insulator  38  that have leads  22 C and  22 D extending therethrough respectively. The holes  42 C and  42 D are positioned at a greater radial dimension from an axis of the machine than are holes  42 A and  42 B. Additionally, the holes  42 C and  42 D are positioned within channels  60  and  64  in the insulator  38  that will be described below. 
         [0016]    The insulator  38  includes the inner perimetrical channel shown herein as inner circumferential channel  60  and the outer perimetrical channel shown herein as outer circumferential channel  64  (also shown in  FIG. 4 ). The inner channel  60  routes the lead  22 C from the hole  42 C at a first circumferential end of the channel  60  to a second circumferential end of the channel  60  that is opposite the first circumferential end of the channel  60 . The lead  22 C is threaded through an optional retainer portion  68  of the insulator  38  near the second end of the channel  60  to provide retention of the lead  22 C within the channel  60 . Beyond the retainer portion  68  the lead  22 C is bent radially inwardly and axially relative to the machine such that an end of the lead  22 C is aligned with an end of the lead  22 B. Thus, ends  22 B and  22 C can be electrically connected to one another through the crimp  20 , for example, as described above. Similarly, the outer channel  64  routes the lead  22 D from the hole  42 D at a first circumferential end of the channel  64  to a second circumferential end of the channel  64  that is opposite the first circumferential end of the channel  64 . Because the first circumferential end of channel  60  and channel  64  are located on opposite circumferential ends of the insulator  38 , the lead  22 C is routed in the opposite direction as the lead  22 D. The lead  22 D is threaded through an optional retainer portion  66  of the insulator  38  near the second end of the channel  64  to provide retention of the lead  22 D within the channel  64 . Beyond the retainer portion  66  the lead  22 D is bent radially inwardly and axially relative to the machine such that an end of the lead  22 D is aligned with an end of the lead  22 A. Thus, ends  22 A and  22 D can be electrically connected to one another through the crimp  20 , for example. 
         [0017]    Several features of embodiments disclosed herein contribute to prevention of short-circuiting of the leads  22 . For example, the insulator  38  is made of nonconductive material such as polymer resin that may be fabricated by a process such as injection molding, for example. Additionally, the portion of the leads  22 C and  22 D, that are routed through the channels  60  and  64  respectively, can have an additional nonconductive sleeve (not shown) applied therearound. Walls  72  on either side of the channels  60 ,  64  provide additional protection against short-circuiting of the leads  22 . The retainer portions  66  and  68  help retain the leads  22 D and  22 C respectively within the channels. And further, the cover  18 , when assembled to the machine  10 , serves to entrap the leads  22 C and  22 D within the channels  60  and  64 . 
         [0018]    While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims.