US Patent No. 9,228,573

WABBLE PLATE TYPE VARIABLE DISPLACEMENT COMPRESSOR


Patent No. 9,228,573
Issue Date January 05, 2016 
Title Wabble Plate Type Variable Displacement Compressor
Inventorship Shinji Tagami, Gunma (JP)
Assignee Sanden Holdings Corporation, Isesaki-shi, Gunma (JP)

Claim of US Patent No. 9,228,573

1. A wabble plate type variable displacement compressor, comprising:
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 wabble plate which is connected to said pistons, in which a rotational movement of said swash plate is converted into a
wabble movement of said wabble plate, and which transmits said wabble movement to said pistons to reciprocate said pistons,
and

a rotation preventing mechanism of said wabble plate, wherein:
said rotation preventing mechanism comprises (a) an inner ring provided in a housing movably in an axial direction although
rotation is prevented, and having a plurality of guide grooves for guiding a plurality of balls provided for power transmission,
(b) a sleeve functioning as a wabble central member of said wabble movement of said wabble 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, (c) an outer ring having a plurality of guide grooves for guiding said balls at positions
opposing respective guide grooves of said inner ring, supported on said sleeve wabblingly, and connected with said wabble
plate fixedly on an outer periphery of said outer ring, and (d) a plurality of balls held by said guide grooves formed in
said inner ring and said outer ring at a condition of opposing each other and performing power transmission by being compressed
between said guide grooves,

a relative shape difference in axial cross-sectional profile is provided between a substantially concave spherical surface
formed in an inner periphery of said outer ring functioning as a wabble member for wabblingly connecting said wabble plate
in said rotation preventing mechanism and a substantially convex spherical surface formed on an outer periphery of said sleeve
functioning as said wabble central member, and

said shape difference is set such that the closer to axial opposite ends of a contact portion between said substantially concave
spherical surface and said substantially convex spherical surface a position of said contact portion is located, the greater
a clearance between both surfaces becomes.