Abstract:
A mounting structure for mounting a device to an electric motor having an output shaft, the mounting structure comprising:
       a body including an opening for receiving the output shaft through the body,   a plurality of connector elements supported by the body; and   a plurality of threaded inserts, each of said inserts being inserted in one of said plurality of connector elements for receiving a fastener to connect the body to the motor;   wherein each connector element is sized and shaped for alternatively receiving an insert in at least two, non-coincident locations within the connector element.

Description:
RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 60/969,413, filed on Aug. 31, 2007, entitled, “Mounting Flange, Pump having Mounting Flange and Mold for Mounting Flange”, which is incorporated herein by reference to the extent permitted by law. 
     
    
     FIELD 
       [0002]    The present application relates to mounting structures such as those used to mount pumps to motors, and more particularly to mounting structures capable of being mounted to motors having different configurations that may be molded using a single reconfigurable mold. 
       BACKGROUND 
       [0003]    Pumps and other devices may be powered by motors connected to the devices. The devices are usually connected to the motors by screw fasteners. Sometimes a common pump may is used with motors having differing fastener configurations. For example, a common pump may be used with motors made by different manufacturers or with different size motors. Because different motors have different fastener configurations, pumps having different fastener configurations must also be made. Substantially identical pumps having different fastener configurations may be needed to connect to different motors. Producing and stocking similar pumps having different fastener configurations adds to product cost. 
         [0004]    Among other reasons for increased pump cost, different fastener configurations sometimes require different molds to make the different pumps. Because molds typically are expensive to manufacture, a need exists for a mold that can make pumps and devices having different fastener configurations. 
       SUMMARY 
       [0005]    In one aspect, the present invention includes a mounting structure for mounting a device to an electric motor having an output shaft. The mounting structure comprises a body including an opening for receiving the output shaft through the body and a plurality of connector elements supported by the body. Further, the mounting structure includes a plurality of threaded inserts. Each of the inserts is inserted in one of the connector elements for receiving a fastener to connect the body to the motor. Each connector element is sized and shaped for alternatively receiving an insert in at least two, non-coincident locations within the connector element. 
         [0006]    In another aspect, the present invention includes a mold for forming a mounting structure for use in mounting an electric motor. The mounting structure includes a connector element and an insert inserted in the connector element in one of at least two non-coincident locations. The mold comprises a first mold member and a second mold member adapted for selectively mating with the first mold member to form a mold cavity sized and shaped for forming the mounting structure having the connector element positioned thereon. The mold also includes a mold sub-insert selectively attachable to the second mold member for forming a cavity in the connector element for receiving the insert. The sub-insert is positionable in at least two non-coincident positions relative to the second mold member for selectively forming the receptacle in a corresponding one of at least two non-coincident locations on the connector element. 
         [0007]    In still another aspect, the present invention includes an electric motor assembly comprising an electric motor having an output shaft and an end having an alignment feature formed thereon. The assembly also includes a mounting structure comprising a body including an opening for receiving the output shaft through the body and a plurality of connector elements mounted on the body for connecting the mounting structure to the motor. The mounting structure also includes an alignment feature on the body adapted to engage the alignment feature formed on the end of the motor for maintaining alignment between the mounting structure and the electric motor. 
         [0008]    Various refinements exist of the features noted in relation to the above-mentioned aspects of the present invention. Further features may also be incorporated in the above-mentioned aspects of the present invention as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to any of the illustrated embodiments of the present invention may be incorporated into any of the above-described aspects of the present invention, alone or in any combination. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0009]      FIG. 1  is a perspective of an electric pump assembly; 
           [0010]      FIG. 2  is a perspective of the pump assembly partially separated; 
           [0011]      FIG. 3  is an alternate perspective of the assembly shown partially separated; 
           [0012]      FIG. 4  is a fragmentary side elevation of the assembly showing a mounting structure in partial section taken along line  4 - 4  in  FIG. 1 ; 
           [0013]      FIG. 5  is a detail of an endshield of an electric motor of the assembly as indicated in  FIG. 2 ; 
           [0014]      FIG. 6  is an alternate perspective of the electric pump assembly; 
           [0015]      FIG. 7  is a perspective of a mounting structure of a first embodiment without inserts; 
           [0016]      FIG. 8  is the perspective of the mounting structure of the first embodiment showing threaded inserts removed from the mounting structure; 
           [0017]      FIG. 9  is an alternate perspective of the mounting structure of the first embodiment; 
           [0018]      FIG. 10  is the perspective of a mounting structure of a second embodiment having one threaded insert separated from the structure, the alternate perspective being identical to  FIG. 9 ; 
           [0019]      FIG. 11  is a perspective of a mold for making the mounting structure of either embodiment; 
           [0020]      FIG. 12  is a perspective of an upper mold member showing a sub-insert of the mold separated from the mold member and oriented for forming the mounting structure of the first embodiment; and 
           [0021]      FIG. 13  is the perspective of  FIG. 12  showing the sub-insert separated from the mold member and oriented for forming the mounting structure of the second embodiment. 
       
    
    
       [0022]    Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0023]    Referring to  FIG. 1 , an electric pump assembly of the present invention is designated in its entirety by the reference number  20 . The assembly  20  includes an electric motor, generally designated by  22 , and a centrifugal pump, generally designated by  24 . As illustrated in  FIG. 2 , the electric motor  22  includes a generally cylindrical case  26 , a front endshield  28  at one end of the case, a back endshield  30  at an end of the case opposite the front endshield, and a selectively rotatable drive shaft  32  projecting through the front endshield. In the illustrated embodiment, the electric motor includes a bracket  34  for attaching the motor  22  to a support on a larger apparatus such as a spa tub. As will be appreciated by those skilled in the art, the drive shaft  32  rotates about its imaginary longitudinal axis when electricity is supplied to the motor  22 . A shoulder  36  is provided on the front endshield  28  of the motor  22  for centering the pump  24  on the shaft  32 . Because the electric motor  22  is conventional, it will not be described in further detail. 
         [0024]    As shown in  FIGS. 2 and 3 , the centrifugal pump  24  includes a primary enclosure or housing  38  having a threaded inlet port  40  and a threaded outlet port  42 , each of which is adapted to be attached to conduits (not shown) for transporting fluid to and from the pump. The enclosure  38  houses an impeller  44  that is operatively connected to the drive shaft  32  of the motor  22 . In one embodiment, the impeller  44  is connected to the drive shaft  32  by a coupling  46  so the impeller turns with the drive shaft. As the impeller  44  turns, it draws fluid into the pump  24  through the inlet port  40  and expels fluid out of the pump through the outlet port  42 . 
         [0025]    As further illustrated in  FIG. 2 , the pump  24  includes a mounting structure, generally indicated at  50 , having a volute body  52  surrounding by a flange  54 . In one embodiment, the mounting structure  50  is molded as a single piece of polymeric material but may be formed as several pieces and joined together. For example, the volute body  52  may be formed separately from the flange  54  and assembled to the flange with fasteners or adhesive. Although the pump  24  is illustrated as being a centrifugal pump, those skilled in the art will appreciate that the pump may be another type without departing from the scope of the present invention. Moreover, those skilled in the art will appreciate that the principles of the present invention may be applied to motors attached to devices other than pumps. 
         [0026]    As shown in  FIG. 3 , the flange  54  of the mounting structure  50  is generally circular. Further, the mounting structure  50  includes a central opening  56  allowing the drive shaft  32  of the motor  22  to pass through the mounting structure to the pump impeller  44 . The mounting structure  50  also includes a plurality of connector bosses or elements  58  spaced angularly around the central opening  56  for connecting the flange to the motor  22 . The connector elements  58  are joined by an annular wall  60  and supported by radial ribs  62 . One or more of these ribs  62  may include a notch  64  for engaging the shoulder  36  on the motor  22  front endshield  28  to center the mounting structure  50  on the motor. In one embodiment, each connector element  58  has a generally racetrack-shaped cross section and projects axially outward from the mounting structure  50  in a direction opposite the volute body  52 . 
         [0027]    Referring to  FIG. 4 , the connector elements  58  are each adapted to receive an insert  66  made of a material having sufficient strength to resist damage from fastener loading. Although the insert  66  may be made from other materials without departing from the scope of the present invention, in one embodiment each insert is made of brass suitable for retaining a fastener  68 . For example, in one particular embodiment the fastener  68  received by the insert  66  is a threaded bolt or stud as shown in  FIG. 5 . Further, in one embodiment the insert  66  includes a rough (e.g., knurled or fluted) exterior to improve interface shear strength with the connector elements  58 . Inserts  66  having other configurations (not shown) may be used without departing from the scope of the present invention. More particularly, the connector elements  58  are formed with cylindrical cavities  70  sized to receive the threaded inserts  66  and retain them in the cavities. For example, in one embodiment the cavities  70  are sized to have an interference fit with the inserts  66  so the inserts may be pressed into place. In another embodiment, the inserts  66  are molded into the connector elements  58 . In still another embodiment, it is envisioned that the inserts  66  may be adhesively bonded in position. 
         [0028]    As illustrated in  FIG. 6 , each connector element  58  has a void  72  to reduce the amount of material needed to form the connector element. As further shown in  FIGS. 7 and 8 , the voids  72  are shaped on their sides adjacent the cavities  70  so that the walls separating the voids and the corresponding cavities have a generally constant thickness. Thus, the voids  72  have an overall crescent-shaped cross section. Other configurations of cavities and voids may be used without departing from the scope of the present invention. In one embodiment, the voids  72  could be omitted entirely. 
         [0029]    Different motors  24  may have different fastener positions. The shape of the connector elements  58  permits the mounting structure  50  to be easily molded in more than one configuration for mounting the same centrifugal pump  24  to different motors  22  having different fastener positions. For example, the motors  22  may have different fastener diameters, different radial fastener positions or different circumferential fastener spacing, but the pump itself would have a similar internal configuration. 
         [0030]    In a second embodiment illustrated in  FIG. 10 , the connector elements  58 ′ could be arranged to connect to different motors  22  having similar circumferential fastener spacing but different radial fastener positions. The cavities  70 ′ for receiving the threaded inserts  66 ′ can be disposed on the radially outer ends, and the voids  72 ′ on the radially inner ends of the connector elements  58 ′. The construction of the mounting structure  50 ′ of  FIG. 10  is identical to the mounting structure  58  of  FIGS. 6-8 , except for the location of the cavities  70 ′ and the voids  72 ′, which are reversed from the location of the cavities  70  and voids  72  of the first embodiment. The parts of the mounting structure  50 ′ of  FIG. 10  will be given the same reference numerals as the mounting structure  50 , but with the addition of a trailing prime (′). The mounting structure  50 ′ is constructed for receiving mounting bolts (not shown) located radially farther outward than the bolts  66  that are received by the mounting structure  50  of  FIGS. 6-8 . Moreover, the threaded inserts  66 ′ have a different inner diameter for receiving a different diameter fastener. The outside diameter of the threaded inserts  66 ′ is the same as that of the threaded inserts  66  of the first embodiment so the same size cavities  70 ′ are used in both embodiments. 
         [0031]    The mounting structures  50 ,  50 ′ having different threaded insert cavity  70 ,  70 ′ and void  72 ,  72 ′ positions can be formed in the same mold, generally designated  80  in  FIGS. 11-13 . The mold  80  includes a first mold member  82  and a second mold member  84  that are joined and separated as known to those of ordinary skill in the art. The first mold member  82  is formed to shape the volute  50 ,  50 ′ and the second member  84  is formed to create the opposite side of the mounting structure  50 ,  50 ′ including the connector elements  58 ,  58 ′. The second mold member includes sub-inserts  86  that can be used to form both the connector elements  58  of  FIGS. 1-7  and the connector elements  58 ′ of  FIG. 8 . The sub-inserts  86  comprise a stepped base  88 , a cavity core  90  and a void core  92 . The cavity core  90  and void core  92  both project from the base. The cavity core  90  has a generally cylindrical shape, and the void core  92  has a roughly crescent shape, corresponding to the shape of the cavity  68 ,  68 ′ and void  70 ,  70 ′, respectively. Each sub-insert  86  is releasably mountable on the second mold member  84  so that the sub-insert can be removed through the back of the second mold member as shown in  FIG. 12 . It is envisioned that the cores  90 ,  92  may be replaced with other cores (not shown) having different configurations. The base  88  is generally rectangular in shape with rounded corners, and is received in a correspondingly rectangular aperture  94  in the second mold member  84 . It will be appreciated that the base  88  can be received in one of two positions in the aperture  94  of the second mold member. In a first of these positions illustrated in  FIG. 12 , the sub-insert  86  is arranged so that the cavity core  90  is located radially inward from the void core  92  for forming the mounting structure  50  as shown in  FIG. 8 . In the second position illustrated in  FIG. 13 , the sub-insert is arranged so that the cavity core  90  is located radially outward from the void core  92  for forming the mounting structure  50 ′ as shown in  FIG. 10 . Thus, it may be seen that by simply detaching the sub-insert  86 , rotating it and reinserting the sub-insert into the second mold member  84 , the second mold member can be converted to selectively produce either the mounting structure  50  of the first embodiment or the mounting structure  50 ′ of the second embodiment. No separate sub-insert is required. 
         [0032]    The previously described shoulder  36  and notched ribs  62  engage each other to align the shaft  32  of the motor  22  with the pump  24 . These features prevent the shaft  32  and pump  24  from becoming misaligned which can damage seals in the pump. These features are particularly advantageous when the electric pump assembly  20  is jarred during transport. 
         [0033]    When introducing elements of the present invention or the preferred embodiments(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
         [0034]    In view of the above, it will be seen that several advantages are achieved by the present invention. 
         [0035]    As various changes could be made in the above constructions, products, and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.