Axial piston pump:
An axial piston pump is a positive displacement that has a number of pistons arranged in a circular array within a housing which is commonly referred to as a cylinder block. Axial piston pumps may be an in-line or angle design.
The major components of a typical, fixed-displacement in-line pump are the housing, a drive shaft, a rotating group, a shaft seal, and a valve plate. A rotating group consists of a cylinder block that is splined to a drive shaft, a splined spherical washer, a spring, nine pistons with shoes, a swash plate, and a shoe plate. One end of the cylinder block is flat and wears against a mating surface on a stationary valve plate. The valve plate has two semicircular ports that allow inlet of the operating fluid and exhaust of the outlet fluid respectively. The inlet and outlet fluid of the pump pass through different parts of the sliding interface between the cylinders block and valve plate. When a rotating group is assembled, a spring forces a cylinder block against a valve plate and a spherical washer against a shoe plate. This action holds the piston shoes against swash plate, ensuring that the pistons will reciprocate as the cylinder turns
Fig. in-line axial piston pump