Abstract: An in-line axial piston hydraulic pump has a cylinder block with a plurality of bores in which separate pistons slide. The cylinder block is supported on one side by a bearing and axle arrangement. The other side of the cylinder block has an integral shaft with a ball that is received in a spherically concave socket coupled to the housing. The socket provides a drive surface that is non-orthogonal to the rotational axis of the cylinder block and the pistons ride against that surface. The engagement of the pistons with that socket surface produces the sliding movement of the pistons within the bores and thus the pumping action.