PDM transmission with articulated torque transfer

An articulated transmission disposed to transmit torque via misaligned rotation, the transmission comprising:

• a shaft having a shaft centerline about which the shaft is disposed to rotate, the shaft providing a plurality of shaft wings on one end thereof, the shaft wings extending generally radially from the shaft centerline;
• each shaft wing providing a shaft bearing surface;
• a generally cylindrical housing having a housing centerline about which the housing is disposed to rotate, the housing having a plurality of housing receptacles formed therein, each housing receptacle for receiving a corresponding shaft wing;
• and
• a plurality of unitary torque transfer elements (UTTEs), each UTTE providing a UTTE spherical surface and a planar UTTE bearing surface on opposite sides of the UTTE;
• wherein each housing receptacle provides a housing bearing surface wherein a housing recess is formed in each housing bearing surface;
• wherein a shaft wing and a UTTE are received into each housing receptacle such that within each housing receptacle, the UTTE spherical surface is received into the housing recess and the UTTE bearing surface opposes the shaft bearing surface;
• wherein, responsive to misaligned rotation of the shaft centerline with respect to the housing centerline and regardless of angular deflection of the shaft centerline with respect to the housing centerline experienced within each housing receptacle during an articulated revolution of the shaft:
• (1) the UTTE bearing surfaces are free to slidably displace against corresponding shaft bearing surfaces;
• (2) the housing recesses restrain the UTTEs from movement in at least a radial direction with respect to the housing centerline;
• and (3) the UTTEs are free to tilt within the housing recesses.