ROTATION PREVENTION MECHANISM FOR OSCILLATION PLATE OF OSCILLATING-SWASH-PLATE TYPE VARIABLE-CAPACITY COMPRESSOR, AND CONSTANT-VELOCITY UNIVERSAL COUPLING CONFIGURING THE SAME

PROBLEM TO BE SOLVED: To provide a rotation prevention mechanism for an oscillation plate and a constant-velocity universal coupling, which endure usage under dilute lubrication in an oscillating-swash-plate type variable-capacity compressor, have superior processability, provide a high material yield, and enable cost reduction.SOLUTION: A rotation prevention mechanism M for the oscillation plate 43 of the oscillating- swash-plate type variable-capacity compressor 39 is formed of the constant-velocity universal coupling 70. The constant-velocity universal coupling comprises an outer coupling member 73 with an even number of linear track grooves formed on the inner peripheral surface, an inner coupling member 71 with an even number of linear track grooves formed on the outer peripheral surface, and torque-transmitting balls arranged between track grooves of the outer coupling member and the inner coupling member. The track grooves of the outer coupling member are provided two at a time so as to slant with left-right symmetry. The grooves of the inner coupling member are provided in the opposite direction from the grooves of the outer coupling member. The outer coupling member is attached to the oscillation plate and the inner coupling member is attached to a center axis, and at least one of constituent members of the constant-velocity universal coupling is formed of a metal sintered compact, and a hardened layer is formed on the surface thereof by heat treatment, characteristically.