HYDRAULIC START DIAGRAM
Hydraulic cranking systems operate on the principle of pressure oil turning a fluid motor to produce mechanical energy. The oil is stored in a pre-charged, piston-type accumulator and is admitted to the hydraulic cranking motor through a starter control valve. The oil enters the motor through an inlet port and is directed against a series of pistons located within a cylindrical rotor. When the pistons receive the pressurized oil, they move against an angularly mounted fixed thrust bearing. As they contact the bearing they slide downward around the race carrying the rotor with them, causing it to turn. After discharging its work load the oil is returned through the motor outlet port to the oil reservoir.
The engine pump system includes equipment for automatically recharging the accumulator, namely an engine belt driven hydraulic pump with unloading valve and high pressure filter.
The hand pump is for emergency use if accumulator supply is exhausted.