Sometimes bigger isn’t better—but having the perfect fit for the application is. Engineers rely on Eaton’s mobile medium-duty closed-circuit hydrostatic piston pumps for exactly that fit in vehicles using mid-range pump/motor hydraulic systems. Rated for operating at pressures up to 380 bar (5,500 psi) while powered by engines of less than 82 kW (110 hp), Eaton medium-duty pumps offer the perfect middle ground solution for a variety of applications.
In axial piston pumps, the pistons reciprocate parallel to the axis of rotation of the cylinder block. The simplest type of axial piston pump is the swash plate in-line design.
The cylinder block in this pump is turned by the drive shaft. Pistons fitted to bores in the cylinder block are connected through piston shoes and a shoe plate, so that the shoes bear against an angled swash plate causing the pistons to reciprocate. The ports are arranged in the valve plate so that the pistons pass the inlet as they are pulled out and pass the outlet as they are forced back in.
The displacement of axial piston pumps is determined by the size and number of pistons, as well as the stroke length which is determined by the angle of the swash plate.
Variable Displacement Piston Pumps are used in closed loop systems either as a single or tandem pump. Oil is circulated by the pump to the motor and then returned directly back to the pump. A charge supply is used to supplement the closed loop system with oil. The charge supply may be supplied by an internal charge pump (standard) or an external source.