Hydraulic axial discharge pump

A hydraulic axial discharge pump, comprising:

• a) a housing;
• b) a first subassembly within said housing including a plurality of cylinder-piston units, said cylinder-piston units being arranged at a distance from, and in one of being parallel to and being at an acute angle to, a central axis and being circumferentially offset, relative to each other, around said central axis by a predetermined angle;
• c) a second subassembly being coaxially positioned and arranged for rotation around said central axis on a drive shaft, said second subassembly further having a force-transmitting connection with said cylinder-piston units so as to receive oscillating drive forces of said cylinder-piston units;
• d) said drive shaft, including at least two rotationally coupled longitudinal sections, coaxially extending along said central axis from a drive input end and through a corresponding central opening of at least one of said first subassembly and of said housing;
• e) said first subassembly including a lubricant system being positioned in a vicinity of said central axis and at least partially within a radial space between said cylinder-piston units, and to extend over an axial length which is covered at least partially by an axial length of said cylinder-piston units;
• f) said lubricant system including a lubricant pump being arranged on one of said at least two rotationally coupled longitudinal sections of said drive shaft and in a rotational drive connection therewith;
• and
• g) a head-subassembly including a filler pump coupled with said drive shaft, a flow path of said filler pump being connected in series with a main flow path of the hydraulic axial discharge pump to deliver substantially an entire admission flow at an enhanced hydraulic input pressure to said cylinder-piston units sufficient for avoiding cavitation.