Abstract:
According to the invention, a flexible coupling for flexibly coupling two rotating or moveable members, comprising a unitized body having a first end, a second end, and therebetween having two or more longitudinally (axially) spaced discs, wherein each disc can include a body portion and one or more spacer portions, wherein the spacer portions can extend longitudinally from an upper surface or lower surface of the body portion. The spacer portions can serve to axially space the body portions from each other and can also serve to unitize the discs and to space the unitized discs from the first and second end and can further serve to join the unitized discs to the first and second end.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a flexible coupling for use in co-axially joining two rotating or moveable members, and more particularly to a manufactured flexible coupling utilized to join two rotating shafts, and which will allow angular, axial, and parallel misalignment while still transmitting torque between the two shafts. 
         [0002]    Prior art flexible couplings, used for interconnecting a wide variety of rotating members, are offered in a variety of configurations to accommodate parallel, axial, and angular misalignments, while still transmitting torque between the driving and driven members. Two basic types are currently available, single and multi-piece flexible couplings. Single piece flexible couplings include radial, helical, and spiral slotted beam types, along with bellows and injection molded types. These types of couplings are either formed from a single piece of material, or are welded, brazed, or adhesive bonded into a single unitary construction. Multi-piece flexible couplings incorporate flexible metal discs or a non-metallic flexible material coupled to driving and driven ends. Flexible couplings of these prior art types, designed for high torsional stiffness and large torque capacity, cannot accept large misalignments without substantial reductions in life expectancy. Flexible couplings of these prior art types, designed for large misalignments, have low torsional stiffness and low torque capacity. 
         [0003]    It is the object of this present invention to provide a novel flexible coupling which is economical to produce, while still having the capability to allow for large misalignments and cycle life with high torsional stiffness and torque capacity. 
       BRIEF SUMMARY OF THE INVENTION 
       [0004]    According to the invention, a flexible coupling for flexibly coupling two rotating or moveable members, comprising a unitized body having a first end, a second end, and therebetween having two or more longitudinally (axially) spaced discs, wherein each disc can include a body portion and one or more spacer portions, wherein the spacer portions can extend longitudinally from an upper surface or lower surface of the body portion. The spacer portions can serve to axially space the body portions from each other and can also serve to unitize the discs and to space the unitized discs from the first and second end and can further serve to join the unitized discs to the first and second end. 
         [0005]    According to the invention, the discs can be joined to each other or first and second ends. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0006]    Reference will be made in detail to various embodiments of the invention, which are illustrated in the accompanying drawing figures. The figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of various embodiments, it should be understood that it is not intended to limit the scope of the invention to particular embodiments described. 
           [0007]    Certain elements in selected views of the drawings may be illustrated not-to-scale, for illustrative clarity. Elements of the figures are numbered such that similar (including identical) elements may be referred to with similar numbers in a single drawing. Such relationships, if any, between similar elements in the same or different figures will become apparent throughout the specification, including, if applicable, in the claims and abstract. 
           [0008]    The structure, operation, and advantages of the present preferred embodiment of the invention will become further apparent upon consideration of the following description taken in conjunction with the accompanying drawings, wherein: 
           [0009]      FIG. 1  is a side view of a flexible coupling in vertical orientation showing two discs, each with a body portion and two spacer portions, and a first and second end; 
           [0010]      FIG. 2  is an exploded perspective view of the flexible coupling of  FIG. 1 ; 
           [0011]      FIG. 3  is a side view of a disc with spacer portions; 
           [0012]      FIG. 4  is a top view of the disc with spacer portions as shown in  FIG. 3 ; 
           [0013]      FIG. 5  is a cross sectional view taken along lines  5 - 5  of  FIG. 4 ; 
           [0014]      FIG. 6  is a perspective view of the disc and spacer portions shown in  FIG. 3 ; 
           [0015]      FIG. 7  is a side view of one embodiment of a disc with spacer portions; 
           [0016]      FIG. 8  is a bottom perspective view of the disc shown in  FIG. 7 ; 
           [0017]      FIG. 9  is a top perspective view of the disc shown in  FIG. 7 ; 
           [0018]      FIG. 10  is a bottom view of the disc shown in  FIG. 7 ; 
           [0019]      FIG. 11  is an enlarged cross sectional view taken along lines  11 - 11  of  FIG. 10 ; 
           [0020]      FIG. 12  is an exploded view of the disc shown in  FIG. 7 ; 
           [0021]      FIG. 13  is a side view of a flexible coupling in vertical orientation showing five discs of one embodiment with spacer portions and a first and second end; 
           [0022]      FIG. 14  is a bottom perspective view of a first end of the flexible coupling as shown in  FIG. 13 ; 
           [0023]      FIG. 15  is a top perspective view of a second end of the flexible coupling as shown in  FIG. 13 ; 
           [0024]      FIG. 16  is a perspective view of a flexible coupling shown in use coupling a driving member and a driven member. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    Referring now to  FIG. 1  and  FIG. 2 , there is shown a flexible coupling  101  that is an embodiment of the present invention having two longitudinally (axially) spaced discs, between a first and second end. The orientation references described herein are selected arbitrarily as a matter of convenience to illustrate relative orientation of features in one embodiment, and that it will be understood that the described structure can be utilized in any orientation. As seen by the views of  FIGS. 1 and 2 , the flexible coupling  101  can have two discs  1   a,    1   b,  (collectively referred to as discs), the discs being of multi-component construction including a body portion  4   a,    4   b,  and spacer portions  3   a,    3   b,    3   c,    3   d  (collectively referred to as spacer portions), the spacer portions extending longitudinally from an upper or lower surface of the body portion, where each spacer portion can be a non-contiguous component with respect to each other spacer portion, and where the body portion can be a non-contiguous component with respect to the spacer portions and where the spacer portions can be joined to the body portion to form a disc of unitized construction comprised of multiple components. The discs can be longitudinally spaced and joined to each other to form a unitized group of discs unitized with use of the spacer portions  3   b,    3   c,  along axis of revolution AR. First and second ends  2   a,    2   b  can be joined to the unitized group of discs through spacer portions  3   a,    3   d  of discs  1   a  and  1   b,  along AR to complete the flexible coupling  101 . All components of flexible coupling  101  can share a common axis of revolution AR, shown extending through the coupling  101 . First and second ends  2   a,    2   b,  which can be regarded as hubs serve as hubs for coaxially connecting each of the first and second ends  2   a,    2   b  to a driving member and driven member respectively. The thickness and type of material utilized in the body portion can vary, as can the materials utilized for the spacer portions and first and second ends. In one embodiment, the material for the body portion can be high strength steel and the spacer portions and hubs can be plastic. In the embodiment of  FIGS. 1 and 2 , each disc spacer portion shown can be of unitary construction. Likewise, each disc body portion can be of unitary construction. 
         [0026]      FIGS. 3 through 6  show a disc  1   a  with body portion  4   a  and spacer portions  3   a,    3   b.  As shown in the views of  FIGS. 3-6 , body portion  4   a  can have an upper surface and a lower surface and, as is readily apparent from the drawings, spacer portion  3   a  can extend longitudinally from the lower surface of body portion  4   a,  while spacer portion  3   b  can extend longitudinally from the upper surface of body portion  4   a.  Spacer portions  3   a  and  3   b  can be rotationally offset from each other about AR, as shown in  FIGS. 1 and 2 , and spacer portions  3   a  and  3   b  can vary in number, shape, size, and rotational spacing. Disc  1   a  can have a center hole  6  which can be of varying size and shape to affect the stiffness and strength of the disc. The thickness and type of material utilized in the body portion can also vary, as can the materials utilized for the spacer portions. The body portion can be flat with an upper and lower surface, and these surfaces can be planar and parallel. In the embodiment described with reference to  FIGS. 1 through 6 , the described spacer portions can be joined to body portions by various methods including by adhesive bonding. 
         [0027]      FIGS. 7-9  show another embodiment of a disc. In the embodiment of  FIGS. 7-9 , a disc  1   c  includes body portion  4   b  and spacer portions  3   e  and  3   f.  As seen by the views of  FIGS. 7-9 , spacer portions  3   e  and  3   f  can be radially disposed in equal proportions about the body portion  4   b.  Spacer portions  3   e,  which extend primarily longitudinally upward from the body portion, can include locating formations that can be provided by locating formations provided by raised locators  8   a,  while spacer portions  3   f,  which extend primarily longitudinally downward from the body portion, can include locating formations that can be provided by holes  7   a.  The raised locators  8   a  and holes  7   a  can be formed in such a way as to mate with each other. Such structure can ease assembly and joining of one disc to another, according to an assembly process one disc can be placed on top of another disc, rotated to align the bottom facing holes  7   a  of the top disc with the top facing raised locators  8   a  of the bottom disc, and the two discs can be aligned and joined as these two geometric features  7   a  and  8   a  mate. As seen in the embodiment of  FIGS. 7-9 , the spacer portions  3   e  can extend primarily longitudinally upward from the surface of the body portion, however, the spacer portions  3   e  can also extend slightly longitudinally downward from the lower surface of the body portion and contiguously slightly inward from the inner diameter  11  of the body portion and slightly outward from the outer diameter  12  of the body portion. Such a configuration allows for a complete encapsulation of the body portion  4   b,  by the spacer portion  3   e.  The same holds true for spacer portion  3   f,  however in an opposite longitudinal orientation to spacer  3   e.  In the embodiment of  FIGS. 7 through 9 , each disc spacer portion shown can be of unitary construction. Likewise, each disc body portion can be of unitary construction. 
         [0028]      FIG. 11  shows a cross section through spacer portion  3   f  and body portion  4   b,  with hole  7   a,  as taken along lines  11 - 11  of  FIG. 10 , showing a complete encapsulation of the body portion by the spacer portion. 
         [0029]      FIG. 12  shows an exploded perspective view of the disc shown in  FIG. 7 . As seen from the view of  FIG. 12 , the spacer portions  3   e  and  3   f  can be joined to the body portion  4   b  through slots  9   c  and  9   d,  the slots  9   c  and  9   d  representing the volumetric geometry of spacer portions  3   e  and  3   f  taken up by body portion  4   b  as the spacer portions encapsulate the body portion. In one embodiment, as will be described herein, spacer portions  3   e  and  3   f  can be injection molded about the body portion by way of a process of insert injection molding. As can be seen, the holes  10  in the body portion can be aligned with the spacer portions  3   e  and  3   f,  and allow the spacer portion to join contiguously to itself through hole  10  defined intermediate of an inner diameter  11  and an outer diameter  12  of spacer portion  4   b,  further strengthening its encapsulation of the body portion. Such result may be further observed in  FIG. 11  as the spacer portion fully encapsulates the body portion. 
         [0030]      FIG. 13  shows an assembled flexible coupling  102  that is an embodiment of the present invention, having five longitudinally (axially) spaced discs between a first and second end,  2   c  and  2   d.  As seen by the embodiment of  FIG. 13 , the flexible coupling  102  can have, e.g., five discs  1   c,  (collectively referred to as discs). The discs can be aligned about AR and interlocked in an alternating manner utilizing locating formations e.g., the holes  7   a  and raised locators  8   a  of the spacer portions. The unitized group of discs can then be joined to the first and second end along AR utilizing the spacer portions in closest proximity to the first and second ends. The first and second ends can have locating formations, e.g., holes and raised locators identical to the features identified on spacer portions  3   e  and  3   f  to facilitate alignment, assembly, and joining of the first and second ends to the unitized group of discs. 
         [0031]      FIG. 14  and  FIG. 15  show perspective views of first end  2   c  and second end  2   d  as seen by the views of  FIGS. 14 and 15 . First end  2   c  and second end  2   d,  which can be regarded as hubs, can include holes  7   a  and raised locators  8   a  respectively, which can be provided according to size and spacing of holes  7   a  and raised locators  8   a  of spacer portions  3   e  and  3   f.  The locating formations can facilitate alignment, assembly, and joining of the first and second ends to the unitized group of discs. 
         [0032]    First hub  2   c  and second hub  2   d  can be adapted to be joined to a driving member  13  and a driven member  14 , respectively. In one embodiment, the hubs can have cylindrical holes in them which can accommodate equivalent sized cylindrical driving and driven shafts, and set screws which can extend radially through each hub to clamp each hub to its respective driving or driven shaft. 
         [0033]      FIG. 16  shows a flexible coupling  103  in use coupling a driving member and a driven member along an axis of rotation AR. Flexible coupling  103  can be provided in accordance with the embodiment described in connection with flexible coupling  101  or flexible coupling  102  or can comprise an alternative embodiment, e.g., can incorporate elements of both flexible coupling  101  and flexible coupling  102 . Flexible coupling  103  can couple a driving member  13 , supplying rotational power to a first end, and a driven member  14 , which sees the rotational power provided by driving member  13  through a second end, as transmitted through flexible coupling  103 . Hub  2   e  can be joined to driving member  13  and hub  2   f  can be coupled to driven member  14 . In one embodiment, hub  2   e  can be provided in accordance with the embodiment described in connection with hub  2   a.  In another embodiment, hub  2   e  can be provided in accordance with the embodiment described in connection with hub  2   c.  In one embodiment, hub  2   f  can be provided in accordance with the embodiment described in connection hub  2   b.  In another embodiment, hub  2   f  can be provided in accordance with the embodiment of hub  2   d.  In one embodiment driving member  13  can represent the motor shaft of an electric motor, and the driven member  14 , can represent the input shaft of a pump, for example. 
         [0034]    Compared to prior art designs, the flexible coupling described herein in various embodiments offers great flexibility in the selection of materials and assembly methods to meet a variety of requirements. The multi-component feature of the described disc offers many advantages. For example, the multiple component disc feature allows the disc to be manufactured with high strength at reduced cost and with complex geometries which aid in the assembly of a complete flexible coupling having multiple discs. 
         [0035]    The locating formations described herein that aid in the alignment of adjacent disc can be formed by a process of injection molding. Such process of injection molding can be simplified with reduced cost by injection molding a disc spacer portion of unitary construction as a non-contiguous component with respect to a disc body portion. In the embodiments shown, the disc body portion can be of simple construction and can be formed by way of a process of stamping. In one embodiment, the non-contiguous spacer portion and body portion components of a disc described herein can be of like or similar material, e.g., each spacer portion and each body portion can be metal, and in one particular embodiment, each spacer portion and each body portion of a disc can be formed of the same metal. In a particular embodiment, the spacer portions can be formed by way of metal injection molding. 
         [0036]    In another embodiment, disc body portions as described herein can be formed of metal and disc spacer portions can be formed of plastic. The body portion, for example, can be a metal in the form of high strength steel, while the spacer portions can be formed of plastic. As plastic is well suited for injection molding, and because plastic injection molding technologies are well established, selection of plastic as a material for a component of a multi-component disc can yield additional cost and structural advantages. Plastic offers numerous advantages in the multi-component disc structure described herein. Injection molding the spacer portions allows locating formations of the spacers to be readily formed. Also utilizing insert injection molding (also known as overmolding) selection of plastic as a material for forming disc spacer portions allows for spacer portions to be molded around a metal insert, to fully or partially encapsulate that metal insert. The body portion of the disc can be high strength steel and would do the actual flexing, while the spacer portion of the disc would serve to rigidly join one disc to the next, or one disc to an end portion. 
         [0037]    A suitable plastic for the spacer portions described herein is material from the product family sold under the trade name ZYTEL by DuPont. Material of the ZYTEL product line offers high strength, stiffness, durability, and chemical resistance, while maintaining excellent injection molding properties. Injection molding the spacer portions around the body portions allows the spacer portions to fully encapsulate the body portion, while at the same time creates location and assembly features such as holes or raised locators on the spacer portions which can mate during assembly. 
         [0038]    Plastics of the ZYTEL product line that can be used to form spacer portions described herein include ZYTEL nylon resin and ZYTEL HTN, which is available in specific product number identifiers HTN51, HTN52, HTN53, HTN54. 
         [0039]    A further advantage of utilizing plastic for the spacer portions is the ease with which spacer portions of adjacent discs may be joined together utilizing ultrasonic welding or adhesive bonding, both economical and high strength bonding techniques. The strength of such joining between spacer portions of adjacent discs can be increased by including on the spacer portions the locating formations as described herein. Locating formations as described herein, while aiding alignment, increase a surface area of an interface between spacer portion and a component joined thereto (e.g., a hub, a disc spacer portion, a disc body portion) as described herein. 
         [0040]    The first and second ends can also be injection molded plastic, a process which can mold a complete part including a cylindrical bore suitable for joining to a driving or driven member, radial threaded holes for set screw clamping the first or second end to the driving or driven member, and locator features identical to those of the spacer portions to facilitate aligning assembling and joining the unitized discs to the first and second end. 
         [0041]    The number of discs in embodiments described herein can easily be increased or decreased as determined by how much misalignment can be expected and how much torque must be transmitted. Also, the type and thickness of material utilized for the body portion can be varied to accommodate stiffness and torque requirements, as can the size, number, and spacing of the spacer portions. The present design, utilizing multi-component and multi-material configuration, offers significant cost advantages over existing products and designs, without sacrificing desirable performance characteristics. 
         [0042]    While various particular embodiments have been described, it will be understood that the features and aspects described with reference to one particular embodiment described can be used with any other particular embodiment described. 
         [0043]    While this invention has been described in the specification and illustrated in the drawings with respect to a preferred embodiment, it is understood that all changes and modifications that come within the spirit of the invention are desired to be protected. Undoubtedly, many variations or equivalents may be substituted for elements of the invention by one having ordinary skill in the art to which the present invention most nearly pertains, and such variations are intended to be within the scope of the invention; as disclosed herein.