Dear Friends,

I am looking to Design a self reversing diamond lead screw for cable winding on a new underwater winch application i am working on at present.

Following are the data's -

Winch drum core - 200 mm
cable dia - 7 mm
no of lays - 27

Gear ratio - 2: 1 , Main shaft 150 RPM , Lead screw - 75 RPM

Screw prawl travel - 187 mm ?
Pitch on the diamond screw - 14 mm ?

I would need to have some design drawings on the diamond screw . how the profile is cut and marked is what i would like to know to complete the shaft on my own.

Any other example design of a diamond screw will also help.

Thanks in advance.

Kind Regards,

Jana

 

Hi Abilash,

With the pitch you have indicated (14mm) that is going to be a very thin pawl - which I think may give you a number of issues. (The pawls and levelwinds I have designed - have typically been for spooling cables down to a diameter of 16mm). It is unclear from your posting what sort of line pull you are talking about - but assuming it is not massive - then my suggestion would be to approach the problem slightly differently and do one of the following:-

1. Consider using a small fleet angle - see the document below for an explanation of this - and you will not need a levelwind bar full stop. You might like to go and have a look at a telescopic crane - and you will see that they do not have any spooling device - they just rely on the very small fleet angle - and the drum self spools.
http://www.bridon.com/usa/x/download...et%20angle.pdf

2.Consider driving an ordinary ISO trapezoidal lead screw (clockwise and anti-clockwise) which thus moves a nut onto which you have the guide rollers attached - which ensures the wire is at the right position on the drum. This could be done with a DC electric motor - with a control algorithm - that moves the nut and guide rollers at the right speed across the front of the drum. This technology already exists - and has been used on subsea tether management systems.

Hope this helps.