XNUMX. The gap between the matching parts in the coupling.
XNUMX. Unbalance caused by uneven or unsymmetrical distribution of accessories (threaded connections, keys, and shaft end pressure plates) in the coupling.
XNUMX. Unbalance caused by uneven material or uneven wear of each part of the coupling.
XNUMX. Tolerances specified in the balance calibration specification.
XNUMX. Errors in balance correction equipment, instruments and mandrel components for correction.
XNUMX. Obvious changes in the unbalanced state of the rotor caused by temperature changes.
XNUMX. The imbalance caused by the manufacturing tolerances specified in the design specifications for the main parts of the elastic coupling (semi-coupling, etc.).
XNUMX. Unbalance caused by the eccentricity between the coupling and the shaft (the cylindricity of the shaft hole and its coaxiality with the outer edge).
XNUMX. The error caused when the coupling is reassembled and installed on the two connected shafts after balance correction.