Abstract: A joint structure for bonding a ball portion and a shaft portion, with the ball including a mounting hole bored toward a center thereof. A corrugated surface for effecting the bonding is formed in an inner circumferential surface of the mounting hole. A shaft portion, of a softer material than the ball portion, is fitted into the mounting hole of the ball portion. An outer circumferential portion of the shaft portion is plastically locally deformed in the vicinity of a corrugated surface of the mounting hole with the ball portion and the shaft portion being are bonded to each other with a tightening force.

Abstract: A fluid machine comprises a cylinder block mounted on a rotary shaft, a rotary plate an axis of which is intersecting with an axis of the rotary shaft by an acute angle, a gear engaging mechanism for engaging the rotary plate with the rotary shaft to cyclically rotate the same, a piston supported by the rotary plate and inserted into a throughhole provided in the cylinder block a suction system and a delivery system for effecting suction and delivery operation by a rotation of the cylinder block and the piston, a spherical contact portion disposed between the rotary plate and the rotary shaft and adapted to receive thrust generated between the same, and a passage for leading to the spherical contact portion a high-pressure working gas including lubricating oil generated in the delivery system.