Abstract:
Embodiments are directed an elevator machine comprising: a stator assembly, and a plurality of support plates coupled to the stator assembly, wherein a respective at least one of the support plates is coupled on each end of the stator assembly and configured to enable the stator assembly to expand radially and axially in a substantially uniform manner over a range of temperatures.

Description:
BACKGROUND 
       [0001]    Traditional elevator machines have an internal rotor motor placed next to a traction sheave.  FIG. 1  illustrates an example of such a machine  100 , with an internal rotor motor  102  next to a traction sheave  104 . The machine  100  may be associated with a number of disadvantageous characteristics. For example, the machine  100  may be long or large, may have high mass, and may subject a rotating shaft to fatigue stresses. 
         [0002]      FIG. 2  illustrates an example of another machine  200 . The machine may address a number of the disadvantages associated with the machine  100 . The machine  200  may include an external rotor motor  202  located inside or within an envelope of a traction sheave  204 . However, referring to the machine  200 , a stator and stator support structure  300  as shown in  FIG. 3  are very stiff, which leads to high stresses when the stator thermally expands. As a result, motor reliability and lifetime are reduced or degraded. Also, using the machine  200 , there is no space available to move bearings  206  within the envelope of the sheave  204 . Thus, much like the machine  100 , the machine  200  is quite long or large. 
       BRIEF SUMMARY 
       [0003]    An embodiment is directed to a method for reducing the size of an elevator machine, comprising: constructing a stator assembly, and coupling the stator assembly to at least one support plate configured to enable the stator assembly to expand radially and axially in a substantially uniform manner. 
         [0004]    An embodiment is directed to an elevator machine comprising: a stator assembly, and a plurality of support plates coupled to the stator assembly, wherein a respective at least one of the support plates is coupled on each end of the stator assembly and configured to enable the stator assembly to expand radially and axially in a substantially uniform manner over a range of temperatures. 
         [0005]    Additional embodiments are described below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The present disclosure is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements. 
           [0007]      FIG. 1  illustrates an elevator machine in accordance with the prior art; 
           [0008]      FIG. 2  illustrates an elevator machine in accordance with the prior art; 
           [0009]      FIG. 3  illustrates a non-flexible stator support structure in accordance with the prior art; 
           [0010]      FIG. 4  illustrates an exemplary machine; 
           [0011]      FIG. 5  illustrates a cross-section of the machine of  FIG. 4 ; 
           [0012]      FIG. 6  illustrates a portion of the machine of  FIG. 4   
           [0013]      FIG. 7  illustrates a portion of the machine of  FIG. 4 ; 
           [0014]      FIGS. 8A-8B  illustrate exemplary support plates; 
           [0015]      FIGS. 8C-8D  illustrate exemplary embodiments of support plates coupling a stator and a shaft; and 
           [0016]      FIG. 9  illustrates a flow chart of an exemplary method in accordance with one or more embodiments of the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    It is noted that various connections are set forth between elements in the following description and in the drawings (the contents of which are included in this disclosure by way of reference). It is noted that these connections in general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. A coupling between entities or components may refer to either a direct or an indirect connection. 
         [0018]    Exemplary embodiments of apparatuses, systems and methods are described for reducing the size or length of a machine, such as an elevator machine. In some embodiments, the machine may be configured to allow bearings to be within an envelope of a sheave or stator. In some embodiments, a stator support plate may be of a particular dimension and shape/geometry to allow a stator assembly to expand radially and axially. Such expansion may occur over a range of temperatures in a substantially uniform manner (e.g., with a variation that is less than a threshold) without subjecting stator components to excess stress or strain. 
         [0019]      FIG. 4  illustrates a layout of an exemplary machine  400  in accordance with one or more embodiments. The organization and arrangement of the various components and devices shown and described below in connection with the elevator system  400  is illustrative. In some embodiments, the components or devices may be arranged in a manner or sequence that is different from what is shown in  FIG. 4 . In some embodiments, one or more of the devices or components may be optional. In some embodiments, one or more additional components or devices not shown may be included. 
         [0020]    The machine  400  may include a bedplate  402 . The bedplate  402  may serve as a base or support for the machine  400 . The bedplate  402  may support the machine  400  when the machine  400  is installed in, e.g., an elevator system. 
         [0021]    The machine  400  may include one or more stands, such as stands  404 . The stands  404  may be used to provide support for the machine  400  and may be used to provide a (minimum) clearance with respect to the operative components of the machine  400 . 
         [0022]    The machine  400  may include one or more brakes  406 . The brakes  406  may be selectively coupled to one or more brake discs  408 , which may be used to bring an elevator car to a controlled stop. 
         [0023]    The machine  400  may include a sheave  410 . The sheave  410  may be used to hold or support a rope, a cable, a belt, etc., for purposes of facilitating movement of an elevator car within an elevator system. 
         [0024]    The machine  400  may include one or more terminal boxes  412 . A terminal box  412  may be arranged on a stationary frame on a side of the sheave  410  and may be used to provide for one or more points of connection (e.g., electrical connection). 
         [0025]    Referring now to  FIG. 5 , a cross-section of the machine  400  is shown. The machine  400  may have a motor, which is illustratively shown in  FIG. 5  as being comprised of a rotor  502  and a stator  504 . The rotor  502  may be coupled to the sheave  410  that may be used to deliver power (e.g., mechanical power) to drive or move an elevator car. As described further below, the stator  504  may be coupled to a shaft  506 , potentially via one or more plates. 
         [0026]    As shown in  FIG. 5 , the machine  400  may include housings  508  that may contain a bearing  510 . The bearing  510  may be used to constrain motion in a particular way (e.g., in a particular direction). The bearing  510  may sit on a stationary shaft while a spinning part or component may be attached to the brake disc  408  and through a bolted joint connected to both ends of the sheave  410 . In some embodiments, oil maintenance may be performed through ports placed on the housing  508 . 
         [0027]    A portion of the machine  400  is indicated via an enclosed circle ‘A’ in  FIG. 5 . A closer or more detailed view of the portion ‘A’ is shown in  FIG. 6 . As shown in  FIG. 6 , the bearings  510  may be at least partially enclosed within an envelope of the sheave  410 . Thus, the machine  400  may be made smaller relative to the machines  100  and  200 . For example, partially enclosing the bearings  510  within the envelope of the sheave  410  may facilitate a reduction in the size of the machine  400 . 
         [0028]    Referring now to  FIG. 7 , the portion ‘A’ of the machine  400  is shown with additional details not shown in  FIG. 6 . Specifically, as shown in  FIG. 7 , the machine  400  may include a stator assembly  702 . The stator assembly  702  may include a support hub with motor laminations and windings attached to an outside diameter. 
         [0029]    The stator assembly  702  may be supported by flexible plates  704  on both ends of the stator assembly  702 . A closer view of the plates  704  is shown in  FIGS. 8A-8D . The thickness and/or geometry of the plates  704  may allow the stator  504  or stator assembly  702  to expand radially and/or axially in a uniform manner without subjecting components of the stator  504  to unnecessary strain or stress. The dimensions or thickness of the plates  704  may be selected based on simulation. A bigger or larger diameter for the stator or shaft may enable thicker walls to be used for the plates  704 . 
         [0030]    The plates  704  may be shaped to allow the machine bearings (e.g., bearing  510 ) to be partially or completely recessed within an envelope  830  of the stator  504  or sheave  410 . For example, as shown in  FIG. 8C , the plates  704  may include an angle  840  to facilitate coupling the stator  504  and the shaft  506  (via the bearings  510 ). The angle  840  may be a substantially right angle. The angle  840  may have a range associated with it, such as being between seventy degrees and one-hundred ten degrees. 
         [0031]    To allow for the flexibility of the plate  704 , the angle  840  may be located such that the stator (e.g., stator  504 ) is allowed to expand. Such expansion (or contraction) may occur over a range of temperatures. The location of the angle  840  may be based on one or more factors or considerations. For example, the location of the angle  840  may be selected based on a provisioning of one or more cooling mechanisms or holes, a size or thickness of one or more flanges that may be used to transmit torque, etc. 
         [0032]    As shown in  FIG. 8D , in some embodiments the bearings might not be recessed within the envelope  830 . Also, the plates  704  are shaped like a coil or snake. Much like the embodiment of  FIG. 8C , the embodiment of  FIG. 8D  may allow for a reduction of stress in the stator  504  during thermal expansion by allowing the stator  504  to expand substantially uniformly in the radial and axial directions. 
         [0033]    The plates  704  may be constructed of one or more materials. For example, one or more metals may be used. The plates  704  may be constructed of aluminum, ductile iron, steel, an iron-based alloy, etc. 
         [0034]    The plates  704  may be configured to include a cylindrical extension  850  toward the center of the stator assembly to guide cooling air over heat sink fins. Windows  860  in the support plates  704  may allow for cooling air to exit the stator assembly  702 . 
         [0035]    Turning now to  FIG. 9 , a flow chart of an exemplary method  900  is shown. The method  900  may be used to design, manufacture, or modernize a machine for an elevator. For example, the method  900  may be used to reduce the size or dimensions of the machine, allowing the machine to fit within, e.g., a smaller machine room. 
         [0036]    In block  902 , a stator (e.g., stator  504 ) or stator assembly (e.g., stator assembly  702 ) may be constructed. The stator/stator assembly may include one or more of the entities or components, such as those described herein. 
         [0037]    In block  904 , the stator assembly constructed in block  902  may be coupled with one or more plates (e.g., plates  704 ). The plates may be used to provide support for the stator assembly and may be used to reliably connect the stator assembly to a shaft over a range of temperatures. As part of block  904 , a shape or geometry for the plates may be selected to achieve one or more features, such as those described herein. The plates may be constructed in accordance with one or more specifications. The specifications may include details regarding the thickness, geometry, shape, and/or material for the plates. 
         [0038]    In block  906 , bearings associated with the machine may be recessed within an envelope of a stator/stator assembly or a sheave associated with the machine. As part of block  906 , the envelope may be established. 
         [0039]    The method  900  is illustrative. In some embodiments, one or more of the blocks or operations (or portions thereof) may be optional. In some embodiments, the operations may execute in an order or sequence different from what is shown. In some embodiments, one or more additional operations not shown may be included. 
         [0040]    Embodiments of the disclosure may provide for a number of technical effects and benefits. For example, stator end plate design may allow for bearings to be at least partially recessed within an envelope of a sheave, thereby reducing the overall size or length of a machine. Stator end plate design and flexibility may reduce the stress imposed on a stator due to or during thermal expansion, thereby enhancing motor reliability and extending operational life of the motor. 
         [0041]    In some embodiments, an external rotor design and stator end plate design may allow a motor airgap to decrease uniformly as temperature increases. Accordingly, high temperature operating efficiency may be improved compared to convention internal rotor motors. The risk of motor noise may be reduced as well due to the uniformity of the airgap under elevated temperature conditions. 
         [0042]    In some embodiments, integrated air deflectors may be used to eliminate extra parts and connections, thereby improving reliability and cost. 
         [0043]    In some embodiments various functions or acts may take place at a given location and/or in connection with the operation of one or more apparatuses, systems, or devices. For example, in some embodiments, a portion of a given function or act may be performed at a first device or location, and the remainder of the function or act may be performed at one or more additional devices or locations. 
         [0044]    Aspects of the disclosure have been described in terms of illustrative embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. For example, one of ordinary skill in the art will appreciate that the steps described in conjunction with the illustrative figures may be performed in other than the recited order, and that one or more steps illustrated may be optional.