ROTATION PREVENTION MECHANISM FOR OSCILLATION PLATE OF OSCILLATING-CAM-PLATE TYPE OF VARIABLE-CAPACITY COMPRESSOR, AND CONSTANT-VELOCITY FREE COUPLER FOR CONFIGURING SAME

摘要

Provided is a rotation prevention mechanism (M) for an oscillation plate (43) of an oscillating-cam-plate type of variable-capacity compressor (39) in which the rotation prevention mechanism (M) for the oscillation plate (43) is formed of a constant-velocity free coupler (70). The constant-velocity free coupler (70) comprises an outer coupling member (73) with an even number of linear track grooves (85) formed on an inner peripheral surface, an inner coupling member (71) with an even number of linear track grooves (77) formed on an outer peripheral surface, and an even number of torque-transmitting balls (72) arranged between pairs of track grooves (85, 77) of the outer coupling member (73) and the inner coupling member (71). The linear track grooves (85) formed on the inner peripheral surface of the outer coupling member (73) are provided two at a time so as to slant with left-right symmetry. The linear track grooves (77) formed on the outer peripheral surface of the inner coupling member (71) are provided two at a time so as to slant with left-right symmetry in the opposite direction from the paired track grooves (85) of the outer coupling member (73). If the operating angle of the coupler is 0º, and the side surfaces (S) of a virtual regular polygonal pillar with the number of angles corresponding to half the number of balls (72) are arranged so as to be parallel to an axis (K-K) of the coupler and of equal distances from the axis (K-K) of the coupler, then center lines (L2, L1) of the paths of the balls of the linear track grooves (85, 77) that are provided two at a time as pairs of the outer coupling member (73) and the inner coupling member (71) are arranged on the side surfaces (S). A spherical inner peripheral surface (86) of the outer coupling member (73) meshes with a spherical outer peripheral surface (80) of the inner coupling member (71), and the coupling members are characterized in that the outer coupling member (73) is attached to the oscillation plate (43) and the inner coupling member (71) is attached to a center axis (57).