Patent ID: 8783161

Claim:
A wobble plate type variable displacement compressor having pistons inserted reciprocally into cylinder bores, a swash plate rotated together with a rotational main shaft and supported changeably in angle relative to said main shaft, a wobble plate which is connected to said pistons, in which a rotational movement of said swash plate is converted into a wobble movement of said wobble plate, and which transmits said wobble movement to said pistons to reciprocate said pistons, and a rotation preventing mechanism of said wobble plate, characterized in that said rotation preventing mechanism of said wobble plate comprises (a) an inner ring provided in a housing movably in an axial direction while being prevented from rotation and having a plurality of guide grooves for guiding a plurality of balls provided for force transmission, (b) an outer ring having a plurality of guide grooves for guiding said balls at positions opposing respective guide grooves of said inner ring, and connected with said wobble plate on an outer circumference of said outer ring and supported wobblingly together with said wobble plate, and (c) the plurality of balls held by said guide grooves formed in said inner ring and said outer ring and performing force transmission by being held between said guide grooves which oppose each other, and (d) a sleeve functioning as a wobble central member of said wobble movement of said wobble plate, provided on said rotational main shaft to rotate relatively thereto and to move in an axial direction and engaged with said inner ring movably in an axial direction together with said inner ring, and said outer ring is supported wobblingly on said sleeve, and at least any one of said guide grooves opposing each other of said inner ring and said outer ring is formed along a guide groove cross-sectional profile to come into contact with a ball at two points.