Patent Publication Number: US-2022221007-A1

Title: Flexible coupling assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation of U.S. patent application Ser. No. 16/403,229 filed May 3, 2019, the content of is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Technological Field 
     The present disclosure relates to flexible couplings, and more particularly to a flexible coupling assembly including a quill shaft. 
     Description of Related Art 
     A variety of devices are known in the transferring torque between two rotating objects and handling various stresses and misalignments. A specific challenge remaining to be solved is how to transmit power between two gearboxes while accommodating misalignment between those gearboxes. When the amount of angular and axial misalignments are both high, a sliding spline can be utilized to limit axial load on the shaft elements. Creating another load path for the axial forces will further limit axial loads thereby maximizing the amount of angle that a coupling can handle. Conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for a flexible coupling assembly having improved structure and assembly features. There also remains a need in the art for such couplings and components that are economically viable. The present disclosure may provide a solution for at least one of these remaining challenges. 
     SUMMARY OF THE INVENTION 
     A flexible coupling assembly for a power transmission system includes a first shaft defining an axis, configured to connect to a first rotatable member, a first flexible diaphragm coupling configured to have a portion of the first shaft pass axially therethrough, a quill shaft having a circumferential opening configured to receive the first shaft and a locking flange for connecting the quill shaft to the first shaft, the quill shaft further being configured to connect to a second rotating member, and a primary diaphragm coupling shaft positioned radially outward of the quill shaft. The quill shaft can include a second mating portion configured for mating with a second rotating member. The second mating portion can be welded to the quill shaft. 
     At least one flange adapter can be placed between the primary coupling shaft and the first flexible diaphragm coupling. The flange adapter can be welded to the diaphragm coupling and the flange adapter can be bolted to the primary diaphragm coupling shaft. The at least one flange adapter includes a pin hole there through arranged perpendicular to the axis can be and aligned with a first shaft pin hole for receiving a pin therein configured to lock relative movement of the first shaft and the flange adapter. 
     The first shaft can abut an outer periphery of the first flexible diaphragm coupling. The locking flange can include at least one radial protrusion for mating with a cutout within the first mating portion of the quill shaft. At least one radial protrusion can include a wedged portion. 
     The primary diaphragm coupling shaft can include a radial displacement limiter in an inner cavity thereof for regulating radial movement of the quill shaft within the primary diaphragm coupling shaft. The radial displacement limiter can include a deformable material. The radial displacement limiter encloses the quill shaft and abuts against an inner diameter of the primary diaphragm coupling shaft. 
     The quill shaft can adjoin a second side of a second flexible diaphragm coupling and pass through the second flexible diaphragm coupling. The primary coupling shaft can adjoin a first side of the second flexible diaphragm coupling. 
     The quill shaft can include a pin hole there through, arranged perpendicular to the axis, and aligned with a primary coupling shaft pin hole for receiving a pin therein configured to lock relative movement of the quill shaft and primary diaphragm coupling shaft during assembly. 
     The first shaft can include a pin hole there through, arranged perpendicular to the axis, for receiving a pin therein configured to lock relative movement of the first shaft and the flange adapter. The first mating portion can include a pin hole there through. The mating portion of the quill shaft includes a larger outer diameter than an outer diameter of a non-mating portion of the quill shaft. 
     These and other features of the systems and methods of the subject disclosure will become more readily apparent to those skilled in the art from the following detailed description of the preferred embodiments taken in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that those skilled in the art to which the subject invention appertains will readily understand how to make and use the devices and methods of the subject invention without undue experimentation, preferred embodiments thereof will be described in detail herein below with reference to certain figures, wherein: 
         FIG. 1  is a perspective view of a flexible coupling assembly showing a quill shaft; 
         FIG. 1 a    is a perspective view of  FIG. 1 , showing the flexible coupling assembly in a disjointed state; 
         FIG. 1 b    is a perspective view of  FIG. 1 , showing the flexible coupling assembly in a connected state; and 
         FIG. 1 c    is an expanded view of a section  FIG. 1 b   , showing the flexible coupling assembly in a locked state. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject invention. For purposes of explanation and illustration, and not limitation, a partial view of an exemplary embodiment of a flexible coupling assembly in accordance with the invention is shown in  FIG. 1  and is designated generally by reference character  100 . Other embodiments of the flexible coupling assembly in accordance with the invention, or aspects thereof, are provided in  FIGS. 1 a -1 c   , as will be described. The methods and systems of the invention can be used to transmit torque in a more reliable manner. 
     As shown in  FIG. 1 , a flexible coupling assembly  100  for a power transmission system includes a first shaft  102  defining an axis  104 , for connecting to a first rotating member  101   a . The first shaft  102  adjoins and passes through a first flexible diaphragm coupling  106  and lockably connects to a quill shaft  108  by a locking flange  110  (shown in  FIG. 1 a   ). The quill shaft  108  is configured for connecting to a second rotating member  101   b  and transmitting axial forces. For instance, the first shaft  102  can be connected to an engine and the quill shaft  108  can be connected to a propeller (not shown). The quill shaft  108  includes a first mating portion  112  for receiving the locking flange  110  of the first shaft  102  within a circumferential opening  114  (shown in  FIG. 1 a   ). The quill shaft  108  is disposed within a primary diaphragm coupling shaft  109 . The first shaft  102  abuts an outer surface  106   a  of the first flexible diaphragm coupling  106 . The primary diaphragm coupling shaft  109  adjoins a first side  116   a  of a second flexible diaphragm coupling  116  and the quill shaft  108  passes through the second flexible diaphragm coupling  116  and adjoins a second side  116   b  of the second flexible diaphragm coupling  116 . 
     Referring further to  FIG. 1 , the quill shaft  108  spans the entire length of the primary diaphragm coupling shaft  109 . The quill shaft  108  transmits most of the axial load, thereby allowing the misalignment capability of the flexible couplings to be utilized for angular misalignment. The quill shaft  108  accommodates the same angular misalignment that the primary diaphragm coupling shaft  109  accommodates. The first mating portion  112  of the quill shaft  108  includes an outer diameter D 1  (shown in  FIG. 1A ) that is larger than an outer diameter D 2  of a non-mating portion  113  of the quill shaft  108 . The quill shaft  108  further includes a second mating portion  112   a  for mating with the second rotating member  101   b , which can be welded to the quill shaft  108 , or secured in another acceptable way. 
     Referring further to  FIG. 1 , the primary diaphragm coupling shaft  109  includes a radial displacement limiter  120  in an inner cavity  109   a  thereof for regulating radial movement of the quill shaft  108 . The radial displacement limiter  120  can include a deformable material. The radial displacement limiter  120  encloses at least a portion of the quill shaft  108  and abuts against an inner diameter D 3  of the primary diaphragm coupling shaft  109 . The displacement limiter  120  limits the radial movement of the quill shaft  108  and improves the buckling and dynamic performance of the quill shaft  108 . The radial displacement limiter  120  also allows for longer length quill shaft  108  to be used. It is conceived that various shapes, materials, and various numbers of radial displacement limiters can be used, depending on the size of the primary diaphragm coupling shaft and the length of the quill shaft  108 . 
     As shown in  FIGS. 1 a -1 c   , the locking flange  110  includes at least one radial protrusion  110   b  for mating with a cutout of the first mating portion  112  of the quill shaft  108 . The at least one radial protrusion  110   b  can include a wedged section  110   c . Upon installation, the radial protrusion  110   b  is inserted into the cutout and the first shaft  102  is turned. The wedged section  110   c  mates with a surface  112   d  of the mating portion  112  and ensures the quill shaft  108  and the first shaft  102  are locked together through friction and pressure. The surface  112   d  of the mating portion  112  can also include features for locking the wedged sections  110   c  in place. The locking flange  110  can include multiple protrusions  110   b  and the quill shaft  108  can have an equal amount of cutouts for receiving said protrusions. 
       FIG. 1 a   , shows the radial protrusions  110   b  and the cutouts separated during installation. At least two flange adapters  118  and  119  are disposed between the primary coupling shaft  109  and the first flexible diaphragm coupling  106  . One of the flange adapters  118  can be welded or secured to the flexible diaphragm coupling  106  and the second flange adapter  119  can be welded or secured to the primary diaphragm coupling shaft  109 . The flange adapters  118 ,  119  help assure separation required for installation. 
       FIG. 1 b    shows the radial protrusions  110   b  within the circumferential opening  114 . The quill shaft  108  includes at least one pin hole  122   a  there through, located within the first mating portion  112 , arranged perpendicular to the axis  104 , and aligned with a primary coupling shaft through hole  122   b  for receiving a pin  123  therein for locking relative movement of the quill shaft  108  and the primary diaphragm coupling shaft  109 . The pin  123  is used during installation and assembly of the shaft and are removed during operation. The first shaft  102  also includes a pin hole there through  122   e , arranged perpendicular to the axis  104 , for receiving another pin therein for locking relative movement of the first shaft  102  and the first flexible diaphragm coupling. The pin hole  122   e  is arranged outside of the locking flange  110 . The flange adapter  118  also includes a pin hole  122   c  there through arranged perpendicular to the axis  104  and which is aligned with the first shaft  102  pin hole  122   e.    
       FIG. 1 c   , shows the radial protrusions  110   b  in a turned and locked position. The pins  123  are shown within each of the aligned holes  122   e  and  122   a . The pins are used during installation and are to be removed prior to operating the shaft. 
     The features discussed herein eliminate the need for a typical ball and socket assembly within each coupling. The typically used ball and socket joints are wear items and need to be replaced after a defined number of service hours. The features discussed above greatly improve the Mean Time Between Maintenance Action (MTBMA) versus shafts using ball and socket assemblies. Further, the mechanism allowing the quill shaft  108  to be separable eliminates the restriction of prior art where the quill shaft length is based on the length of one flexible coupling. 
     The methods and systems of the present disclosure, as described above and shown in the drawings, provide for a flexible coupling assembly with superior properties including increased reliability. While the apparatus and methods of the subject disclosure have been shown and described with reference to embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the spirit and score of the subject disclosure.