Patent ID: 6820567
Filing Date: 2004-11-23
Classification: B63H

Abstract:
A steering apparatus comprising steering means including a steering wheel 13 and a helm pump 10 that can be rotated through desired angles of rotation in both the forward and reverse directions by operating said steering wheel 13 and discharges a liquid of a quantity proportional to said angles of rotation, and double action cylinder means comprising a cylinder 20, a piston 21 and a piston rod 22 provided on a rudder side of the ship as means for moving a rudder 27, said steering means and said double action cylinder means being connected with each other by means of a closed hydraulic circuit, so that the entire liquid that is discharged from the helm pump 10 is introduced via the hydraulic circuit into one chamber of the cylinder 20 of the double action cylinder means and the same amount of liquid is discharged from the other chamber of the cylinder 20 so as to flow through the hydraulic circuit into the helm pump 10, thus constituting said closed hydraulic circuit having fully closed circuit construction as a whole for moving the rudder 27 by an amount corresponding to the amount of liquid introduced into said cylinder 20,wherein said steering apparatus further includes pump means for generating a discharging pressure in the same direction as the discharging direction from the helm pump 10 against the resistive pressure from said closed hydraulic circuit generated during rotation of the helm pump 10 due to the operation of said steering wheel 13 is installed in series in part of the fully closed hydraulic circuit, so that the steering resistance of the steering wheel 13 is automatically reduced by said pump means.