A swash plate (18) can rotate together with a drive shaft (16) through a rotating support (17) and a hinge mechanism (20), and rotation of the drive shaft (16) is converted into reciprocating motion of a piston (23). Guiding provided by the hinge mechanism (20) and a slide supporting action provided by the drive shaft (16) through a through hole (19) permit the swash plate (18) to incline while moving slidingly on the drive shaft (16), and a change in an inclination angle modifies a stroke of the piston (23) for regulation of delivery capacity. An arcuate-shaped support (19a) abuts against the drive shaft (16) to subject the swash plate (18) to the slide supporting action provided by the drive shaft (16). An axis (S) being the center of an arc for the support (19a) is set to be beyond the drive shaft (16) on a side opposite to the hinge mechanism (20) with an axis (L) of the drive shaft (16) therebetween, and defines the center of inclination of the swash plate (18). The support (19a) is increased in hardness by induction hardening to be improved in durability in pressure contact and sliding relative to a peripheral surface of the drive shaft (16).
