PURPOSE: To remove power loss accompanying pump driving by using a variable orifice for adjusting opening corresponding to a variable capacity pump and a vessel speed and by discharging a required flow rate from a pump in order to obtain steering force in responce to said speed.
CONSTITUTION: A variable capacity pump 2 for supplying hydraulic pressure to a power steering gear 3 is constituted by a pump body 21, a slide casing 23 inserted into a space of the body 21 and a pump chamber 25D formed within a space 23A of the slide casing 23. An orifice 9 is provided between the pump 2 and the power steering gear 1, and a flow rate through said orifice is narrowed down by a solenoid 44 as the vessel speed increases. Said pump 2 becomes large in an amount of its eccentricity between the slide casing 23 and the fixed rotor 25 by pressure difference along the orifice produced by narrowing down said orifice and is reduced in its discharge.
KAWAI MASAO
SHIGEMORI TAKAHIRO
