Lifeboat Hydraulic Starting System
Hydraulic cranking system is commonly used on life boat , and operate on the principle of pressure oil turning a fluid motor to produce mechanical energy. The oil is stored in a pre-charged, bladder or piston type accumulator and is admitted to the 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 pressurised 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 to turn. After discharging its workload the oil is returned through the motor outlet port to the oil reservoir. The engine pump system includes equipment for automatically recharging the accumulator supplied with unloading valve , and high-pressure
The use of a hand pump ( muscle energy) is for emergency use if accumulator supply is exhausted and it is capable of regenerating system pressure for a starting attempt. There is also an option to incorporate a pneumatic oil driven pump to externally recharge the accumulator to provide an almost instant start attempt.