Patent Publication Number: US-2021164522-A1

Title: External shaft connection assembly for a vane actuator

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Provisional Patent Application No. 62/942,449, entitled “Vane Actuator Vane Shaft External Connection Construction ( 1 ),” filed on Dec. 2, 2019, and U.S. Provisional Patent Application No. 62/942,463, entitled “Vane Actuator Vane Shaft External Connection Construction ( 2 ),” filed on Dec. 2, 2019. The contents of the aforementioned applications are incorporated herein by reference in their entireties. 
    
    
     FIELD OF DISCLOSURE 
     This disclosure relates to an external shaft connection assembly for a vane actuator. In particular, the external shaft may operably engage the vane actuator to a valve. 
     BACKGROUND 
     Existing connectors for engaging a vane actuator to an external shaft are subject to tolerances issues during manufacturing. As a result, undesirable gaps between the vane and the valve shaft may cause motion transmission errors. 
     In other connectors, motion transmission errors may be addressed by introducing tertiary hardware exterior to the structural body of the actuator, or through structural adjustments made within the actuator. The former approach prevents a flush mounting between the actuator and the valve, thereby requiring additionally costly hardware, while the later approach requires the time consuming disassembly of the actuator. As such, it is desirable to provide a connection structure that minimizes mechanical slop without costly support structures. 
     BRIEF SUMMARY 
     According to one aspect, an external shaft connection assembly for a vane actuator includes an external shaft connector configured to engage the vane actuator and a valve stem. The external shaft connector further includes a first end defining a connector recess configured to receive the valve stem and a second end defining a connector post configured to be received within the vane actuator. The connector post defining a ferrule recess and a perimeter of the connector post having one or more expansion slots. The externals shaft connecter also includes a thru hole in communication with the connector recess and the ferrule recess. 
     In another aspect, the connector post forms a mated connection with the vane actuator. In one aspect, the first end further defines a set screw hole transverse to a longitudinal axis of the external shaft connector and the external shaft connector further comprises a set screw to be received through the set screw hole and configured to engage and compress the valve stem against the connector recess. 
     In yet another aspect, the vane actuator further includes a slot through an exterior housing of the vane actuator aligned with the set screw hole. 
     According other aspects, the external shaft connection assembly also includes an upper shaft engaged the vane actuator opposite the external shaft connector. The upper shaft may be integrated with the vane actuator. Alternatively, the upper shaft is distinct from the vane actuator and further includes a first upper shaft end configured to engage a positioner and a second upper shaft end having an upper shaft post. The upper shaft post is configured to be received within the vane actuator and the upper shaft post defines an upper shaft ferrule recess while an upper shaft perimeter includes one or more upper shaft expansion slots. 
     In one aspect, the upper shaft post forms a mated connection with the vane actuator. The upper shaft may also include a threaded opening to receive a threaded fastener. 
     According to various aspects, the external shaft connection assembly also includes a compression ferrule. The compression ferrule is configured to be received in the ferrule recess. In yet other aspects, the compression ferrule further includes a lower ferrule region that is tapered from a first diameter at a central portion of the compression ferrule to a second diameter at a lower distal end and a ferrule thru-hole extending through the compression ferrule from an upper distal end to the lower distal end. In various aspects, the second diameter is less than the first diameter. 
     According to various aspects, the external shaft connection assembly also includes a connecting fastener. The connecting fastener is configured to be received in a vane shaft of the vane actuator through the external shaft connector, the compression ferrule and received in an upper shaft. In one aspect, the connection fastener is threaded and configured to draw the external shaft connector towards the vane shaft. 
     In another aspect, an external shaft connection assembly for a vane actuator includes an external shaft connector configured to engage the vane actuator and a valve stem. The external shaft connector further including a first end defining a connector recess configured to receive the valve stem, a second end defining a connector post configured to be received within the vane actuator, while the connector post defines a ferrule recess and a perimeter of the connector post includes one or more expansion slots. The external shaft connector also has a thru hole in communication with the connector recess and the ferrule recess. The external shaft connection assembly also has an upper shaft engaged to the vane actuator opposite the external shaft and a compression ferrule configured to be received in the ferrule recess. The compression ferrule further includes a lower ferrule portion that is tapered from a first diameter at a central portion of the compression ferrule to a second diameter at a lower distal end and a ferrule thru-hole extending through the compression ferrule from an upper distal end to the lower distal end. The external shaft connection assembly also has a connecting fastener configured to be received in vane shaft through the external shaft connector, the compression ferrule and received in the vane actuator. The connection fastener is threaded and configured to compress the external shaft connector towards the compression ferrule and the vane actuator such that one or more expansion slots of the external shaft connector expand outward upon compression against the compression ferrule to engage the vane shaft. 
     In various aspects, the upper shaft is integrated with the vane actuator or the upper shaft is distinct from the vane actuator. When distinct from the vane actuator, the upper shaft further includes a first upper shaft end configured to engage a positioner and a second upper shaft end comprising an upper shaft post. The upper shaft post is configured to be received within the vane actuator. The upper shaft post also defining an upper shaft ferrule recess configured to engage the compression ferrule and an upper shaft perimeter having one or more upper shaft expansion slots. The upper shaft ferrule recess further defines a threaded opening. In one aspect, the connecting fastener is further configured to be received in the upper shaft and configured to compress the upper shaft towards the vane actuator while one or more upper shaft expansion slots are configured to expand outward upon compression against the compression ferrule to engage the vane shaft. 
     According to one aspect, an external shaft connection assembly for a vane actuator includes an external shaft connector configured to engage the vane actuator and a valve stem. The external shaft connector further includes a first end defining a connector recess configured to receive the valve stem, where the first end further defines a set screw hole transverse to a longitudinal axis of the external shaft connector. A second end of the external shaft connector defines a connector post configured to be received within the vane actuator. The external shaft connector also includes a set screw to be received through the set screw hole and configured to engage and compress the valve stem against the connector recess. The vane actuator may further be configured to include a slot through an exterior housing of the vane actuator aligned with the set screw hole. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of an external shaft connection assembly according to one aspect. 
         FIG. 2  is a cross section view of the assembled external shaft connection assembly of  FIG. 1 , as viewed along line A-A, according to one aspect. 
         FIG. 3  is a cross section view of the assembled external shaft connection assembly of  FIG. 2 , as viewed along line B-B, according to one aspect. 
         FIG. 4  is a schematic diagram and partial sectional view of the external shaft connection assembly in use according to one aspect. 
         FIG. 5  is an exploded view of an external shaft connection assembly according to another aspect. 
         FIG. 6  is a schematic diagram and partial sectional view of the external shaft connection assembly in use according to another aspect. 
         FIG. 7  is an enlarged view of portion A of  FIG. 6 , according to one aspect. 
     
    
    
     DETAILED DESCRIPTION 
     In various aspects, the external shaft connection assembly is provided to eliminate or mitigate tolerance differences between a vane shaft of a vane actuator and to an external shaft connector. A tolerance difference creates a gap or undesired space that causes inefficiencies, inaccuracies, and deviations from the intended motion transmission from a vane actuator to a valve stem. 
     Referring now to  FIGS. 1-7 , the external shaft connection assembly includes an external shaft connector  40 , according to one aspect. In various other aspects, the external shaft connection assembly further includes a vane assembly  20 , an upper shaft  30 , a compression ferrule  50 , and a connecting bolt  60 . 
     According to one aspect, one end of the external shaft connector  40  defines an external shaft connector recess  41  to receive and engage a valve stem  91  of a connected valve  90 . The valve stem  91  may be rotated with the external shaft connector  40 . Another end of the external shaft connector  40  includes an external shaft connector post  42  that is configured to be received within a vane shaft  21  of the vane assembly  20  and to engage one or more vane shaft connection slots  22 , such that the external shaft connector is rotated by the vane shaft  21 . The external shaft connector post  42  further defines an external shaft connector ferrule recess  43 . Within the external shaft connector ferrule recess  43  the external shaft connector  40  further includes a thru hole  44  that provides communication between the external shaft connector ferrule recess  43  and the external shaft connector recess  41 . In various aspects, the outer perimeter of the external shaft connector post  42  includes at least one external shaft connector expansion slot  45  that extends through to the external shaft connector ferrule recess  43 . 
     The vane assembly  20  may be housed with a vane actuator  70 , as shown in  FIGS. 4-6 , and may be rotated within the vane actuator  70  to control an external valve  90 . In one aspect, the vane assembly  20  includes a vane  26  that defines the vane shaft  21  that further defines one or more vane shaft connection slots  22 . 
     In various aspects, the vane shaft  21  defines a generally octagonal conduit. In other aspects, the vane shaft  21  may define a conduit of any geometry, including but not limited to a square conduit, a splined conduit, double-D conduit, or a keyhole conduit, among others. In various aspects, the outer perimeter of the external shaft connector post  42  and the upper shaft post  31  match or complement the shape of at least a portion of conduit formed in the vane shaft  21  so that the external shaft connector post and the upper shaft post engage the vane shaft in a mated connection. 
     Similarly, in various aspects, vane shaft connection slots  22  may have polygonal and/or rounder perimeters, while the external shaft connector post  42  and the upper shaft post  31  have reciprocal geometries that can engage the connection slots in a mated connection. 
     The upper shaft  30  may be configured to operably engage a positioner  80  to the vane actuator  70 . According tone one aspect, as shown, in  FIGS. 2 and 4 , an upper end of the upper shaft  30  is engaged to the positioner  80 , while, the lower end of the upper shaft has an upper shaft post  31 . The upper shaft post  31  is configured to be received within the vane shaft  21  and to engage one or more of the vane shaft connection slots  22 . The upper shaft post  31  allows rotation of the upper shaft  30  to rotate with the vane shaft  21 . The upper shaft post  31  further defines an upper shaft ferrule recess  32 . The bottom surface of the upper shaft ferrule recess  32  further includes a connecting threaded hole  33 . In various aspects, the outer perimeter of the upper shaft post  31  has one or more upper shaft expansion slots  34  that extend through to the upper shaft ferrule recess  32 . 
     In various other aspects, the upper shaft  30  may be integral with the vane shaft  21 . For example, the vane  26  and the upper shaft  30  may be formed from a single unitary material stock. As such, the upper shaft  30  may be formed without a ferrule recess or any upper shaft expansion slots  34 . In these aspects, a threaded hole may still be formed in a unitary assembly of the vane  26  and upper shaft  30  to engage and secure an external shaft connector  40 . 
     According to one aspect, the compression ferrule  50  defines a ferrule thru hole  51 . At least one of the upper and lower ends of the compression ferrule  50  are tapered thus forming an upper ferrule taper portion  52  and/or a lower ferrule taper portion  53 , respectively. The upper ferrule taper  52  is configured to be received in the upper shaft ferrule recess  32  and the lower ferrule taper  53  is configured to be received in the external shaft connector ferrule recess  43 , when the upper shaft  30  and the external shaft connector  40  are both engaged to the vane assembly  20 . In one aspect as shown in  FIG. 1 , the lower ferrule taper  53  is tapered from a first diameter at the central portion  54  to a second diameter at a lower distal end, while the upper ferrule taper  52  is tapered from a third diameter at the central portion to a third diameter at an upper distal end. 
     In various aspects, only the lower end of the compression ferrule  50  is tapered such that the compression ferrule includes a lower ferrule taper portion  53  without an upper ferrule taper portion  52 . This ferrule configuration may be used whether the upper shaft  30  is separate or integrated with the vane  26 . 
     According to one aspect, the connecting bolt  60  may be engaged to the connecting thread hole  33  of the upper shaft  30  via the thru hole  44  and the ferrule thru hole  51  when the upper shaft  30  and the external shaft connector  40  are both engaged to the vane assembly  20 . The connecting bolt  60  forces the upper shaft  30  and external shaft connector  40  to be compressed against the vane shaft connection slots  22  through the compression ferrule  50 . In one particular example, the lower ferrule taper  53  forces the external shaft connector post  42  expand outwardly, so the outer peripheral surface is forced against the walls of the vane shaft connection slot  22 . This outward expansion is facilitated at least in part by the external shaft connector expansion slot  45 . Likewise, in other aspects, upon tightening the connecting bolt  60 , the upper ferrule taper  52  contacts and expands the upper shaft post  31  outwardly against the walls of the vane shaft connection slot  22 . 
     In various aspects, outward expansion of the external shaft connector post  42  against the walls of the vane shaft connection slot  22  eliminates or greatly mitigates any discrepancies in manufacturing tolerances or gaps initially present between the external shaft connector and the vane shaft  21 . This, in turn, reduces inaccuracies, deviations, and/or transmission loss from the intended motion of the valve. 
     In various aspects, the first end of external shaft connector  40 , further defines a threaded hole  72  transverse to a longitudinal axis of the connector recess  41  and the thru hole  44 . A set screw  71  may be fastened into the threaded hole  72  to contact the valve stem  91  when present in the connector recess  41 . In particular, the set screw  71  presses tightly against the side of the valve stem  91  to reduce inaccuracies and deviations from the intended motion transmission between the valve stem and the external shaft connector  40 . 
     In one aspect, after insertion, the set screw  71  is fully inserted into the threaded hole  72 , such that it does not protrude from the external shaft connecter  40 . In other aspects, the threaded screw may be elongated to protrude from the external shaft connector  40  after contacting the valve stem. 
     To accommodate the use of the set screw  71 , the vane actuator  70  includes a body slot  210  formed within the exterior housing  73  of the vane actuator, according to one aspect. As shown in  FIGS. 5-6 , the exterior housing  73  of the vane actuator  70  is composed of an upper and lower shell. The exterior housing  73  also defines one or more shaft apertures  23  to receive the valve shaft  91  via the external shaft connector  40  and the upper shaft  30 . The body slot  210  permits access to adjust the set screw to reduce motion transmission errors from the exterior of the actuator. As such, adjustments may be made while the vane actuator is in operation. 
     In one aspect, as shown in  FIGS. 6-7 , the valve shaft  91  may be structured to provide a shaft drive  82  to be compatible with variety of valve actuators. As shown the shaft drive  82  may have different dimensions the valve shaft. As such, the set screw  71  may be adjusted to accommodate any shaft drive configuration. 
     Those skilled in the art will appreciate that the presently disclosed aspects teach by way of example and not by limitation. Therefore, the matter contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. For example, although various elements and features may described as lower or upper, they do not limit the arrangement of the assembly as the assembly may be assembled in any orientation. As such, the upper shaft and positioner may not be located above the vane actuator. 
     The following claims are intended to cover all generic and specific features described herein, as well as all statements of the scope of the method and system, which, as a matter of language, might be said to fall there between.