Abstract:
An electrical device including a housing having an inner surface, a lamination assembly and at least one pin extending from an inner surface of the housing. The lamination assembly has at least one slot therein. The lamination assembly is clocked to a position so that the at least one pin coacts with the at least one slot to rotationally orient the lamination assembly. The at least one pin additionally acts to constrain the lamination assembly from axial removal from the housing thereby rotationally and axially limiting movement of the lamination assembly to a predetermined range of movement within the housing.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to an electrical device such as a motor or generator, and, more particularly, to an apparatus and method of indexing and retaining stator laminations in the housing of an electrical device. 
       BACKGROUND OF THE INVENTION 
       [0002]    Electrical devices such as generators and motors include a stator and a rotor. Typically a stator is stationary and a rotor rotates in an electrical device, although the opposite can also be the case. The stator may act as a field magnet interacting with the rotor to create motion in the rotor. Alternatively the stator may receive magnetic fields from the moving field coils of the rotor to thereby produce electrical power from the stator. Although a stator may be a permanent magnet, electromagnets are typically used having what is caused a field coil or field winding that is closely associated with a series of laminations to produce the electromagnet. The laminations are typically of a ferrous material such as silicone steel with the geometry and material type selected to reduce hysteresis and eddy current losses. 
         [0003]    The laminations are typically identically stamped and are stacked in their arrangement with copper winding wire interfacing elements of the laminations to form the electromagnetic field coils of the stator assembly. Typically the stator is then dipped or coated in a varnish-like material to adhere the parts together and to reduce or prevent vibration between the laminations. The stator assembly is then inserted into a housing and secured thereto. The rotor then is inserted inside a central cavity of the stator along with bearings. If the rotor uses electromagnets, then slip rings are also coupled with the rotor to supply electrical conduction pathways to the coils contained in the rotor. 
         [0004]    What is needed in the art is a cost effective way of aligning the stator to the housing as well as retaining it in at least a temporary fashion until being fully secured to the housing. 
       SUMMARY 
       [0005]    The present invention provides for the clocking of a stator relative to a housing to thereby orient the stator rotationally and axially relative to the housing and retaining it thereto. 
         [0006]    The invention in one form is directed to an electrical device including a housing having an inner surface, a lamination assembly and at least one pin extending from an inner surface of the housing. The lamination assembly has at least one slot therein. The lamination assembly is clocked to a position so that the at least one pin coacts with the at least one slot to rotationally orient the lamination assembly. The at least one pin additionally acts to constrain the lamination assembly from axial removal from the housing thereby rotationally and axially limiting movement of the lamination assembly to a predetermined range of movement within the housing. 
         [0007]    The invention in another form is directed to an electrical device having a housing, a stator and at least one pin extending from the inner surface of the housing. The stator has at least one slot along an outer surface of the stator. The stator is clocked to a position so that the at least one pin coacts with the at last one slot to rotationally orient the stator as the stator is inserted into the housing. The at least one pin additionally acts to constrain the stator from axial movement to thereby rotationally and axially position the stator in a predetermined position in the housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0009]      FIG. 1  is an abstract cross-sectional view of an electrical device made utilizing an embodiment of the present invention; 
           [0010]      FIG. 2  is a cross-section view of the stator laminations used in the electrical device of the  FIG. 1 ; 
           [0011]      FIG. 3  is a plan view of a lamination utilized in the stator assembly of  FIGS. 1 and 2 ; 
           [0012]      FIG. 4  is a side view of a stack of the laminations of  FIG. 3  to thereby form the lamination assembly of the stator of  FIGS. 1 and 2 ; 
           [0013]      FIG. 5  is a perspective view of the lamination stack of  FIG. 4 ; and 
           [0014]      FIG. 6  is another perspective view of another embodiment of a stack of laminations of  FIG. 3 . 
       
    
    
       [0015]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION 
       [0016]    Referring now to the drawings, and more particularly to  FIG. 1 , there is shown an electrical device  10 , which can also be an electrical motor or an electrical generator, having a stator  12 , a rotor  14 , and a shaft  16  that is oriented to rotate about axis  18 . Stator  12  can also be understood to be a lamination assembly  12  as further described herein. For the sake of simplicity elements such as slip rings, electrical connections, bearings, windings and the housing of the motor are not illustrated in  FIG. 1 . 
         [0017]    Now, additionally referring to  FIG. 2  there is illustrated electrical device  10 , with stator  12  inserted inside of a housing  20 . Stator  12  has slots  22  and  24  that are shown interacting with pins  26  and  28 . Pins  26  and  28  extend from an inner surface  30  of housing  20  and are shown engaging slots  22  and  24  respectively. Once lamination assembly  12  is inserted into the end of housing  20 , pins  26  and  28  are inserted to allow lamination assembly  12  to be oriented or clocked into position so that slot  22  corresponds with pin  26  and slot  24  corresponds with pin  28 . Although two slots  22  and  24  as well as two pins  26  and  28  are illustrated, other corresponding numbers of each or different numbers of each are also contemplated. Further, for the ease of illustration slots  22  and  24  are shown opposite each other, but other locations are also contemplated. Once lamination assembly  12  is inserted, the end of slots  22  and  24  prevent further axial movement of lamination assembly  12  once they encounter pins  26  and  28 . As can be seen in  FIG. 2  pins  26  and  28  do not extend inwardly to contact the bottom surfaces of slots  22  and  24  thereby allowing lamination assembly  12  to be retained in housing  20 , so that lamination assembly  12  can be positioned and fastened in a conventional manner later in the assembly process. Pins  26  and  28  may be in the form of fasteners or other devices that are inserted through housing  20  to thereby engage slots  22  and  24  with the purpose of rotational alignment or the clocking of lamination assembly  12  and in order to restrain the axial movement beyond the desired position and to prevent the removal of lamination assembly  12  from housing  20 . Pins  26  and  28  constrain the movement of lamination assembly  12  within housing  20  within a predetermined range of movement as determined by the size of pins  26  and  28  as well as the geometry of slots  22  and  24 . Pins  26  and  28  may just hold lamination assembly  12  temporarily until other elements, not shown, are then further secured to housing  20 . 
         [0018]    Slots  22  and  24  may be machined into lamination assembly  12  after the laminations are stacked or otherwise positioned and slots  22  and  24  do not necessarily have a dead end or closed end as illustrated in  FIG. 2  but may extend from one end of lamination assembly  12  to the other end of lamination assembly  12 . Also, slots  22  and  24  may be closed on both ends. Further, although slots  22  and  24  are illustrated as being parallel with axis  18  other configurations and shapes are also contemplated such as a round bore of fixed depth. 
         [0019]    Now, additionally referring to  FIGS. 3-5 , there is illustrated in  FIG. 3  a singular lamination  32  having notches  34  and  36 , and orientation features  38  and  40 . Laminations  32  are chosen to have a desired thickness for the purposes of reducing hysteresis and eddy current losses in the assembly. Laminations  32  may be made in a stamping process having notches  34  and  36  that then will be subsequently aligned so as to form slots  22  and  24  respectively. Orientation features  38  and  40  are shown as examples of features which exist around the surface of lamination  32 . Orientation features  38  and  40  include wiring paths that are oriented so that multiple aligning positions of features  38  and  40  may occur around the surface of lamination  32  such that features  38  and  40  may align while notches  34  and  36  may misalign so that features  38  and  40  can be utilized, for example, for the routing of copper wiring while certain portions of notches  34  and  36  may or may not be aligned. This feature is illustrated in  FIG. 4 , as a stack of laminations  32  that have a first portion  44  of the stack of laminations and a second portion  46  of the stack of laminations. Portion  44  and portion  46  are offset, say for example by ninety degrees, to thereby form slot  42  in a different angular and axial position from slot  22 . This is accomplished by a rotation of portion  46 , for example, of ninety degrees from portion  44  so that notches  34  and  36  do not align between portions  44  and  46 . As seen in  FIG. 5  orientation features  38  and  40  align throughout the length of lamination assembly  12  while slots  22 ,  42  and  48  are formed by the positioning of notches  34  and  36 . The hidden lines illustrate that orientation features  38  and  40  are aligned and extend through the entire lamination assembly  12 . 
         [0020]    In another embodiment of the present invention illustrated in  FIG. 6 , slot  122  can be formed having two dead ends with portions of laminations  32  oriented in one direction and in a second direction and then back to a first direction so that slot  142  is interrupted by the offset and allowing the formation of slot  122 . The elements of  FIG. 6  are conveniently numbered one hundred higher than similar features illustrated in  FIGS. 1-5  and have the same characteristics as those discussed by their lower number counterparts. 
         [0021]    Pin  26  and/or pin  28  are used to precisely control the clocking of lamination assembly  12  so that the size of pins  26  and  28  may correspond to the width of slots  22  and  24 . The looser control of the axial position is available during the assembly and disassembly processes to hold stator  12  proximate to its proper place to prevent stator  12  from backing out of housing  20  during the handling and assembly/disassembly of electrical device  10 . 
         [0022]    As shown in  FIG. 2 , stator lamination stack  12  is inserted into housing  20  also known as a frame. Fixturing can be used to ensure that slots  22  and  24  will line up respectively with radial pins  26  and  28  during the insertion process. When the stack of laminations illustrated as lamination assembly  12  are inserted to the predetermined depth or location, radial pins  26  and  28  can be inserted or inserted further. Pins  26  and  28  engage axial slots  22  and  24  respectively which are formed as notches in lamination  32  or machined to a predetermined depth in the outer surface of the lamination stack. Slots  22  and  24  as illustrated herein only covering a portion of the total lamination stack of lamination assembly  12 . Radial pins  26  and  28  may contain a feature to lock them in to place to prevent them from disengaging from slots  22  and  24 . Once pins  26  and  28  are inserted, lamination assembly  12  is prevented from turning about axis  18  within housing  20  and also from excess axial movement within electrical device  10 . 
         [0023]    Advantageously the present invention adds the combination of a slot on the stator and extending pins so that the stator can be properly oriented within housing  20  during assembly of electrical device  10 . 
         [0024]    While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.