Patent Application
20070295153
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Turning now to the drawings,
It should be noted that where, in the present discussion, reference is made to a driving or a driven element, this is for convenience only. As will be appreciated by those skilled in the art, the couplings and systems of the present invention may be used in a variety of contexts and with power or torque flow in the directions indicated here, or in an opposite direction.
A flexible hub assembly 18 has a mating surface 20 that contacts the front face 12 of the flywheel 10. The flexible hub assembly rotates about an axis or centerline 22. The flexible hub assembly 18 has a number of elements, each of which will be discussed in more detail below, particularly in relation to
An external flange 32 secures the flexible element 24 to a hub 34. Clamping fasteners 36 load against the front face 38 of the external flange 32. The external flange 32 and the other elements used to secure the flexible element 24 to the hub 34 will be described in more detail in the discussion of
The hub 34 has a front face 40 with a plurality of recesses 42 extending into the hub, generally in a circular pattern. The configuration of the recesses 42 provides for a plurality of inner keys 44 and outer keys 46. A plurality of inserts 48 having slots 50 are placed in the recesses 42 and engage the inner keys 44 and outer keys 46. This interface radially locates the inserts 48 in place allowing for the coupling to be blindly stabbed together during assembly, as described below. In a present embodiment, the inserts 48 are self constrained, that is, they fit snuggly into the recesses 42 of the hub 34, facilitating assembly of the coupling system when placed in service. Those skilled in the art will appreciate that the number and geometry of the hub 34 and inserts 48 could be varied from those shown and provide the same functionality. For example, the plurality of inserts 48 could be replaced with a one piece insert ring resulting in the same self constrained locating feature. The present embodiment only illustrates one geometry configuration for the self constrained insert 48 but is not functionally limited to this geometry. Furthermore, the inserts 48 used in the present embodiment are made of rubber or some other compliant material. This material choice results in a conformable cavity 52 eliminating the need for close internal clearance in the coupling. The net effect is that the coupling can transfer more torque and permit somewhat greater misalignment without sacrificing durability. Moreover, the hub 34 is shown with an inside diameter 54 which has the benefit of reducing the weight of the assembly.
The driven shaft 56 rotates about an axis or centerline 58 and is configured to engage a coupling element 60. The coupling element 60 has an inside diameter 62 with an internal key feature 64 that aligns with a key feature 66 in the driven shaft 56. A key 68 is used to transmit torque from the coupling element 60 to the driven shaft 56. The coupling element 60 has an outside diameter 70 with threaded holes 72 extending therethrough into the inside diameter 62. One or more set screws 74 are used to axially secure the coupling element 60 onto the driven shaft 56. Extensions 76 protrude axially from the front face 78 of the coupling element 60. The extensions 76 are configured to engage the cavities 52 formed by the recesses 42 and inserts 48, creating an intermeshing interface. Here again, those skilled in the art will readily appreciate that the number and geometry of the components of this intermeshing interface can be changed and still provide the same functionality. For example, the extensions 76 could be configured to protrude radially from the outside diameter 70 of the coupling element 60 rather than axially as shown. Also the intermeshing interface of the current embodiment could be reversed by having the extensions 76 on the hub 34 and the cavities 52 on the coupling element 60. The present embodiment only illustrates one geometry configuration for this intermeshing interface, but the invention is not functionally limited to this geometry.
The flexible element 24 is coupled to the hub 34 via the clamping force created by the clamping fasteners 36. In particular, the inner periphery 98 of the flexible element 24 is captured by the clamping force created between the front face 82 of the internal flange 80 and the back face 100 of the external flange 32. The external flange 32 has an inside diameter 96 that engages the outside diameter 88 on the hub 34, radially locating the flange.
The blind stab flexible coupling system is ideal in situations where a protective cover 102 or other structure does not allow or limits access to the flexible hub assembly 18. In a typical engine flywheel application, the system is “blindly” stabbed together by installing the flexible hub assembly 18 and protective cover 102 onto and around the flywheel 10. The coupling is then engaged by axially moving the pre-installed coupling element 60 towards the installed flexible hub assembly 18 and blindly stabbing the coupling together, as indicated generally by reference numeral 104. The coupling element 60 approaches the flexible hub assembly via an opening 112 in the protective cover. Those skilled in the art will appreciate the simplicity and ease of engaging the current invention and its advantages over a system that requires the user to access the coupling after the two devices are placed adjacent one another within a cover, support assembly or other surrounding structure. It is especially advantageous where direct access to the coupling is limited due to a protective cover 102.
Once engaged, the coupling system transfers the flywheel torque 106 to the flexible hub assembly 18 via the flexible element 24, resulting in a hub assembly torque 108. The hub assembly torque 108 is then transferred to the driven shaft 56 via the coupling element 60, resulting in a drive shaft torque 110. The driven shaft torque 110 is then transferred from the coupling element 60 to the driven shaft 56 via the key 68 thus completing the coupling function. The compliant nature of the flexible element 24 allows for the misalignment of the flywheel centerline 14 to the driven shaft centerline 58. The flexible element 24 also dampens and isolates vibrations to or from the flywheel 10 to the driven shaft 56. Also, as discussed above, the inserts 48 reduce coupling internal clearance allowing for optimum conversion of flywheel torque 106 to drive shaft torque 110.
While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
