Patent ID: 6106187
Filing Date: 2000-08-22
Classification: F16D,Y10T

Abstract:
A torque-transmitting coupling assembly, said coupling assembly comprising:a) a body having a cylindrical wall bore;a cylindrical shaft extending into said body bore, said shaft having an outside diameter wall which provides a controlled degree of radial play between said shaft and said body bore when said assembly is not under torquing load;c) opposed first and second complementary curved wall concavities, said first concavity being formed in said body bore and said second concavity being formed on said shaft, said curved wall concavities combining to form a recess between said shaft and said body bore;d) a torque-transmitting entrainment key positioned within said recess, said entrainment key being snugly engaged by one of said concavities but loosely engaged by the other of said concavities when said assembly is not under torsion, said entrainment key having a curved outer wall which mimics the curved walls of said recess, said torque-transmitting entrainment key having an axis of elongation which is radially offset from said outside diameter wall of said shaft by a distance (h);e) said body, said shaft, and said entrainment key combining to create torsional drive contact areas between said key, said body and said shaft, which contact areas are associated with the concavity that the entrainment key loosely engages, and which contact areas are located at an intersection between the wall of said first concavity and said body bore wall, or at an intersection between the wall of said second concavity and the outer wall of said cylindrical shaft; andf) said entrainment key being operable to engage one of said torquing drive contact areas in the concavity which the entrainment key loosely engages when said assembly is subjected to torsion in a manner which creates an entraining force (FG) having a tangential component (FT) and a radial component (FR), said tangential component being operable to create torque between said body and said shaft, and said radial component being operable to force said body and said shaft into wall-to-wall abutting contact which continues so long as the assembly is subjected to torsion, said radial component (FR) being created by reason of the loose fit between said entrainment key and said first or second concavity and by reason of said radial offset (h).