Ships Steering Gear / Rudder Hunting Response

[powerjunx]

Hello there, im stuck with rudder that has hunting response at every end stop points of about 2-3 degrees as the following; Midship, port & stbd 30 i.e. rudder actuator keeps activating in response to the error. tried to zero the feedback unit hunting persist at midship position. its Roll-Royce steering gear/rudder system with Anschutz autopilot control unit. maybe some experienced fellows had encounter such problem who are grateful to share some ideas, i appreciate so much.


"..the more, the merrier" Genghis Khan

 

[CH5OH]

so a tenfjord steering gear...
it has been a while but I seem to remember, there is a small orifice hole, close mounted (or even inside) the hydraulic actuator valve, on top of the unit.Try to locate it on the drawing or may be you have an exploded view available of the valve itself. This (clogged) orifice might cause the problem...
(some advice I got from an old technician, when I was visiting the tenfjord factory, prior to take an ulstein offshore vessel out of a Denmark ship shipyard, some years back)

 

[zeusfaber]

Tenfjord or Brown Brothers?

Is this a system with constant or variable delivery pumps? If the latter (lots of Rolls' older systems had them) then have a look at the pump swash feedback.

A.

 

[powerjunx]

Guys, im very glad with your comments. yes, its a tenfjord sg unit (roll royce). However, upon further inspection, its no doubt that the problem laid on control system that is the Anschutz (Ratheon)steering control..where a fine adjustment were carried out to stop the hunting. that is the gain, deadband, etc. Once again thank you guys.


"..the more, the merrier" Genghis Khan