An axial piston machine (1) is shown, comprising: a shaft (2) having an axis (3) of rotation, a cylinder drum (4) connected to said shaft (2) and having at least a cylinder (5) parallel to said axis (3) of rotation, a piston (6) movable in said cylinder (5), a swash plate (13), a slide shoe (11) pivotally mounted to said piston (6), and holding means holding said slide shoe (11) against said swash plate (13), said holding means having a pressure plate (14) and a number of coil springs (15) arranged between said cylinder drum (4) and said pressure plate (14). The object is to have a reliable operation of said machine with a simple construction. To this end each coil spring (15) is at least at one end fixed by a protrusion (20) extending into said coil spring (15).

A variable-displacement engine comprises an engine block, power shaft and rotating cylinder block. Pistons and connecting rods mounted in the cylinder block connect to a wobble plate having a rotating ring portion and non-rotating ring portion connected to allow relative rotation therebetween while constraining the portions to remain parallel. The wobble plate defines an inclination plane, pivot axis and wobble plate angle . A piston control mechanism includes axial lift, control lever supported by the lift and by an anchor bearing, and links connecting the control lever to the wobble plate. Axial movement of the lift changes the axial position of the control lever pivot and changes the control lever angle, in turn changing, via the connecting links, the wobble plate angle and the axial position of the wobble plate pivot axis. This changes the piston displacement of the engine while maintaining substantially constant compression ratio.

The invention relates to a hydraulic axial piston machine (1) of dry case type of construction, whose case (2) is provided for connection to a gearing case (21) so as to form a fluid-tight overall case. The case (2) has openings (10) which permit the passage of leakage hydraulic fluid or of lubricant into the gearing case (21). By means of this design, splashing losses of the axial piston machine (1) are eliminated, and the leakage hydraulic fluid or the lubricant serve for the lubrication both of the axial piston machine (1) and of the gearing (20).

A variable displacement piston assembly including a plurality of cylinders, each cylinder having an axis substantially parallel to the axis of the other cylinders, a plurality of pistons, one piston in each cylinder, and each piston and corresponding cylinder having a displacement. The assembly also including a transition arm having a connector pin for each piston, each connector pin connecting each piston to said transition arm, a drive shaft connected to the transition arm and a control shaft rotatably coupled to the drive shaft, the control shaft being movable to adjust the displacement of the piston assembly.

A variable-displacement engine comprises an engine block, power shaft and rotating cylinder block. Pistons and connecting rods mounted in the cylinder block connect to a wobble plate having a rotating ring portion and non-rotating ring portion connected to allow relative rotation therebetween while constraining the portions to remain parallel. The wobble plate defines an inclination plane, pivot axis and wobble plate angle . A piston control mechanism includes axial lift, control lever supported by the lift and by an axially fixed anchor bearing, and links connecting the control lever to the wobble plate. Axial movement of the lift changes the axial position of the control lever pivot and changes the control lever angle, in turn changing, via the connecting links, the wobble plate angle and the axial position of the wobble plate pivot axis. This changes the piston displacement of the engine while maintaining substantially constant compression ratio.