Patent Document

BACKGROUND OF THE INVENTION 
     Embodiments of the invention relate generally to dynamoelectric machines and, more particularly, to bore connectors for dynamoelectric machines. 
     Rotors of dynamoelectric machines typically comprise relatively large diameter cylindrical bodies containing field windings. These field windings produce magnetic flux which in turn produces current and voltage. Electrical connections are made between the field windings and a bore connector, a conductive material within a relatively small diameter of the rotor. Copper is often the conductive material employed in bore connectors, which are therefore often referred to as “bore coppers.” 
     To date, the primary method of restraining bore connectors within a rotor bore is to reduce clearance between the bore connectors, which are typically comprised of hemispherically-divided halves of an elongate conductive rod, by custom fitting insulating strips between the bore connector halves.  FIG. 1  shows a view of such device  1 , which includes a rotor  2  having a central bore  3  along its longitudinal axis. A bore connector  4 , comprising two connector bodies  10 ,  20  are disposed within central bore  3 . A rigid separator  30  or insulating strip is disposed between connector bodies  10 ,  20 , forcing the arcuate outer surfaces  12 ,  22  of each connector body  10 ,  20 , respectively, against the wall of central bore  3 . However, this can be both time consuming and relatively ineffective, as the bore connectors, in use, often require a greater degree of restraint during operation than can be achieved using insulating strips. 
     Other methods of restraining bore connectors within the rotor bore include wrapping the bore connectors with an insulator, which is then milled such that its outer diameter matches an inner diameter of the rotor bore. This is not only labor intensive and time consuming, but also makes it difficult to insert the bore connectors into the rotor bore. What is more, such methods necessarily guarantee that the degree of restraint cannot be increased after the bore connectors are installed within the rotor bore. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In one embodiment, the invention provides a bore connector for a shaft of a dynamoelectric machine, the bore connector comprising: a pair of elongate connector bodies, each having a substantially hemispherical shape in cross section and at least one of which having: a radially opening aperture including an inner surface, at least a portion of which is threaded; and a threaded member having a threaded outer surface compatible with the threaded inner surface of the aperture, the threaded member being threadable into and out of the aperture. 
     In another embodiment, the invention provides a bore connector for a shaft of a dynamoelectric machine, the bore connector comprising: a pair of elongate connector bodies, each having a substantially hemispherical shape in cross-section, at least one of which having: a radial opening aperture extending from an arcuate outer surface of the elongate connector body through to a substantially planar inner surface of the elongate connector body; and an insert device disposed along the inner surface of the elongate connector body, the insert device including: a body having an internally threaded aperture substantially aligned with the radial opening aperture; and a threaded member having an outer threaded surface compatible with the internally threaded aperture, the threaded member being threadable into and out of the internally threaded aperture. 
     In still another embodiment, the invention provides a bore connector for a shaft of a dynamoelectric machine, the bore connector comprising: a pair of elongate connector bodies, each having a substantially hemispherical shape in cross-section, at least one of which has a radially opening aperture including an inner surface, at least a portion of which is threaded. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings that depict various embodiments of the invention, in which: 
         FIG. 1  shows a known rotor and bore copper. 
         FIGS. 2 and 3  show partial cross-sectional perspective views of a bore copper according to one embodiment of the invention. 
         FIGS. 4 and 5  show partial cross-sectional perspective views of a bore copper according to another embodiment of the invention. 
         FIG. 6  shows a cross-sectional side view of a rotor, bore copper, and terminal plug according to still another embodiment of the invention. 
     
    
    
     It is noted that the drawings of the invention are not to scale. The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements between the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 2  shows a perspective cross-sectional view of a bore connector body  100  according to one embodiment of the invention. For the sake of simplicity of explanation,  FIG. 2  shows only a portion of one of the two connector bodies that would be employed. One skilled in the art will understand that connector body  100  may often be both more elongate and would be used in combination with a similar connector body disposed opposite to the one connector body shown. 
     Bore connector body  100  includes a first radially-opening aperture  120  extending inward from an arcuate outer surface  112  and a second radially-opening aperture  130  extending outward from a substantially planar inner surface  114  to first radially-opening aperture  120 . As shown in  FIG. 2 , first radially-opening aperture  120  includes an unthreaded inner surface  122  and has a first diameter d 1 . As will be explained in more detail below, according to some embodiments of the invention, the inner surface  122  of first radially-opening aperture  120  may be threaded. Second radially-opening aperture  130  includes a threaded inner surface  132  and has a second diameter d 2  greater than first diameter d1. 
     A threaded member  180  has a diameter d 3  substantially equal to second diameter d 2  of second radially-opening aperture  130  and includes a threaded outer surface  182  compatible with threaded inner surface  132  of second radially-opening aperture  130 , such that threaded member  180  may be threaded into and out of second radially-opening aperture  130 . As shown in  FIG. 2 , the smaller diameter d1 of first radially-opening aperture  120  prevents threaded member  180  from entering first radially-opening aperture  120 . This, however, is neither necessary nor essential. In some embodiments of the invention, d 1  may be equal to or greater than d 2 , the embodiment shown in  FIG. 2  being illustrative of one embodiment of the invention. Also according to some embodiments of the invention, threaded member  180  may include an interface  186  at its planar surface  184  to facilitate threading threaded member  180  into and out of second radially-opening aperture  130 . 
       FIG. 3  shows perspective cross-sectional view of connector body  100  with threaded member  180  threaded into second radially-opening aperture  130  and in combination with a rigid separator  300 . Again, one skilled in the art will recognize that a second connector body, not shown in  FIG. 3 , would be disposed opposite connector body  100  with respect to rigid separator  300 . In use, threaded member  180  may be threaded partially out of second radially-opening aperture  120  using, for example, a tool passed through first radially-opening aperture  120  to contact interface  186 . As threaded member  180  moves out of second radially-opening aperture  130 , a force F 1  is exerted against rigid separator  300 . This, in turn, exerts a reciprocal force F 2 , which pushes connector body  100  away from rigid separator  300  and against a wall of a rotor bore within which connector body  100  is disposed. 
     As will be appreciated by one skilled in the art, the ability to increase force F 2  by moving threaded member  180  within second radially-opening aperture  130  allows connector body  100  to be more securely restrained within a rotor bore and does not rely on the use of specially adapted insulating strips. As noted above, the use of such strips may not provide adequate restraint of a bore connector during operation of the rotor. 
       FIGS. 4 and 5  show, respectively, perspective and cross-sectional perspective views of a connector body  200  according to another embodiment of the invention. Again,  FIGS. 4 and 5  show only a portion of one of the two connector bodies that would be employed, as will be apparent to one skilled in the art. Referring to  FIG. 4 , connector body  200  includes an insert device  250  along planar surface  214 . Insert device  250  lies substantially flush with planar surface  214  and includes a third radially-opening aperture  240  extending outward from planar surface  214  to first radially-opening aperture  220 . Third radially-opening aperture  240  includes a threaded inner surface  242  for accepting a threaded member, as used in the embodiment shown in  FIGS. 2 and 3 . 
       FIG. 5  shows a cross-sectional view of connector body  200  with such a threaded member  280  threaded into insert device  250  and in combination with a rigid separator  300 . Similar to the embodiment shown in  FIGS. 2 and 3 , first radially-opening aperture  220  has a diameter d 4  that is less than the diameter d 5  of third radially-opening aperture  240  and the diameter d 6  of threaded member  280 , which are substantially equal. As noted above, however, it is neither necessary nor essential that d 4  be less than d 5 ,  FIG. 5  being illustrative of one embodiment of the invention. Upon threading threaded member  280  out of third radially-opening aperture  240  and exerting a force F 1  against rigid separator  300 , a reciprocal force F 2  is exerted by connector bore  200  against a wall of the rotor bore (not shown). 
     The embodiment shown in  FIGS. 4 and 5 , which includes insert device  250 , may be useful in a number of applications. For example, as noted above, connector body  200  comprises a conductive material, often copper. Copper is a relatively soft metal, which may be deformed upon the application of too great a force. Insert device  250  and threaded member  280 , in some embodiments, may include a harder material, such as steel. In such embodiments, greater force may be exerted on and between insert device and threaded member  280  than could be applied if either were formed from a softer material, such as copper. 
     Other variations of the embodiments of the invention described above are possible, of course, and are within the scope of the invention. For example,  FIG. 6  shows one such embodiment in which the bore connector  400  may be provided with a single radially-opening aperture  420  that extends from the outer arcuate surface  412  through to the planar surface  414 , at least a portion of which is threaded. In some embodiments, such as that shown in  FIG. 6 , the entire radially-opening aperture may be threaded, such that a terminal plug  500  having a correspondingly threaded outer surface  520  may be threaded into the radially-opening aperture  420 . In some embodiments, such as that shown in  FIG. 6 , an end  580  of such a terminal plug  500  may itself function as does the threaded member  180  ( FIG. 2 ) described above. That is, such a terminal plug  500  may be threaded into the radially-opening aperture  420  and against a rigid separator  300 , thereby exerting a force F 1  against the rigid separator  300  and inducing a reciprocal force F 2  of the bore connector  400  against the central bore  3  of rotor  2 . 
     In any of the embodiments of the invention, the threaded member or other device acting as the threaded member may, upon the desired amount of restraint of the bore connector being obtained, be locked or fixed in place to prevent movement of the threaded member or other device and an accompanying reduction in the restraint of the bore connector within the rotor bore. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any related or incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Technology Category: 5