Link-type rotary coupling
AssigneeLord Corporation
InventorWarren E. Schmidt
Life of this patent
Estimating the term…
Abstract
A link-type coupling particularly suited for use in connecting a drive shaft to a rotor hub in an aircraft for permitting the hub to rotate about an axis that may be angularly misaligned with respect to the rotational axis of the drive shaft. The coupling includes a series of links arranged tangentially with respect to the hub and shaft and connected thereto by laminated elastomeric bearings at the ends of the links. The laminated elastomeric bearings accommodate the motion of each link while transferring torque between the shaft and hub.
Claims32
In a link coupling for transmitting torque between rotatable drive and driven members while accommodating angular misalignment between their rotational axes, said link coupling including a plurality of links and attachment means for interconnecting the links to the drive and driven members so that the links can move independently as they advance tangentially about said axes, the improvement wherein each link comprises:
- axially stiff body means for accepting both tensile and compressive loads applied tangentially between said drive and driven members,
- first laminated elastomeric bearing means cooperable with one of said attachment means for connecting a first end of said body means to said drive member to permit the body means to pivot about a first axis while undergoing elastic compression during application of tension to said body means,
- second laminated elastomeric bearing means cooperable with another of said attachment means for connecting a second end of said body means to said driven member to permit pivotal movement of the body means about a second axis parallel to said first-mentioned axis,
- said first and second laminated elastomeric bearing means also permitting pivotal movement of the body means about a third axis extending lengthwise of the body means between said first and second axes,
- said laminated elastomeric bearing means cooperable with said attachment means for enabling said laminated elastomeric bearing means to undergo elastic shearing during said pivotal motion about said axes and to undergo elastic compression when said body means is subjected to tension while rotating about misaligned axes, whereby the link motion necessary to effect a substantially constant velocity connection between misaligned rotatable drive and driven members can be accommodated.
A link for use in connecting drive and driven members in a coupling capable of transferring torque between the members when rotated about axes that may be angularly misaligned with one another comprising:
- a connecting element having a leading end portion and a trailing end portion, said connecting element being axially, flexurally an torsionally stiff with respect to its leading and trailing end portions, a laminated elastomeric bearing mounted at each end of said connecting element, each laminated elastomeric bearing including a mounting attachment means extending transverse to said connecting element for effecting a non-rotative relative connection to its associated drive or driven member and a plurality of convex alternating elastic and relatively non-extensible layers bonded together and to said mounting attachment means and connecting element, said layers permitting said mounting attachment means to pivot orthogonal intersecting axes relative to each end portion of said connecting element at least one of which axes extends longitudinally of the link and to deflect longitudinally of the link, both said pivotal and longitudinal motions occurring without sliding of the mounting attachment means with respect to the connecting element, whereby the link can accept loads applied in either axial direction while accommodating among the plurality of elastic layers axial and pivotal relative movement of the connecting element with respect to the mounting attachment means.
In a link-type coupling for transferring torque between drive and driven members rotatable about misaligned rotational axes, including connectable means located radially outward of their respective rotational axes in spaced confronting relation with one another, and linkage means for connecting said connectable means of said drive and driven members, the improvement wherein said linkage means comprises:
- an axially stiff connecting element extending between said connectable means substantially tangentially to said rotational axes;
- spherical laminated elastomeric bearing means mounted at opposite ends of said connecting element, each of said laminated elastomeric bearing means including at least one relatively inextensible layer bonded to and between a pair of elastic layers;
- attachment means securing said laminated elastomeric bearing means to said connectable means for causing said elastic layers of said laminated elastomeric bearing means to accept in elastic compression axial forces and deflections of the connection element and for causing said laminated elastomeric bearing means to accommodate in elastic shear the pivotal deflections of the connecting element as it advances endwise about said rotational axes;
- whereby a substantially constant velocity rotary connection is provided between the rotatable members.
In an aircraft having a powerplant with a drive shaft and a rotor hub coupled to the drive shaft for rotation therewith about an axis that may be angularly misaligned with respect to the rotational axis of the drive shaft, the rotor hub being drivingly connected to the drive shaft by a link-type coupling having drive means connected to the drive shaft for rotating in a plane orthogonal thereto and having linkage means arranged generally tangentially of said drive shaft axis radially outward thereof for interconnecting the drive means and hub, the improvement wherein said linkage means comprises a plurality of axially stiff links having leading end portions operatively connected to said drive means and trailing end portions operatively connected to said driven hub, laminated elastomeric bearing means mounted in each end portion of each link, and attachment means for connecting said laminated elastomeric bearing means to said drive means and to said hub, said laminated elastomeric bearing means in at least one end of each link cooperable with its associated attachment means during rotation of the drive shaft both to provide a non-sliding elastic shear connection permitting the link to deflect both about its longitudinal axis and about an axis transverse to the rotational axes of the drive and driven means, said laminated elastomeric bearing means also providing an elastic compression connection for transferring link tension to the attachment means and accommodating relative motion between the drive and driven means, whereby a substantially constant velocity drive connection is provided between the powerplant drive shaft and rotor hub.
Dependencies are inferred from the claim text.