Variable-stroke reciprocating pumps (also called variable-displacement pumps) are most commonly used on naval ships as part of an electrohydraulic transmission system. They are used on anchor windlasses, cranes, winches, steering engines, and other equipment. You will have to maintain and make minor repairs to hydraulic and related equipment outside your ships engineering spaces. The information that follows is in addition to that found in Fireman, NAVEDTRA 10520-H. Two general types of variable-stroke pumps are in common use: the axial-piston pump and the radial-piston pump. In the axial-piston pump (fig. 13-13), the pistons are arranged parallel to each other and to the pump shaft. In the radial-piston pump (fig. 13-14), the pistons are arranged radially from the shaft.

Figure 13-14.-Nine-piston (radial-piston) pump.