Flexible shaft specific issue

Reduce the angle of the cable's bend or you may need to look into installing a u-joint or two.

You should contact s.s. white technologies inc. They are the leaders in this field. Their website is www.sswhite.net.

Flexible shafts come in different flexibilities and are often designed for a particular application. What you are describing can definitely be done with a properly designed flex shaft.

What you may also be able to do is to move the driven load a little closer to the driving force so as to lessen the bend angle at the place where the shaft keeps brakeing It sounds as though you are creating a tension bend in the cable. Move the pump an inch or two towards the motor that should eliminate that bend.

Hi

Why don't you use 90 deg gear box?

Hi all! Thanks for your suggestions.

Dear friends, ours is an appliance application and we can not afford bevel gears. As such we are discussing the matter with SS white and they have been of good help. But the applications they suggested are high end not cost effective; although trials are on.

We need to know the reasons; is it fatugue failure, or friction failure. The failed samples do not show signs of friction either on cable or casing. And if it is fatigue then what should be appropriate specification for the cable material. cross section.. we are still speculating and at large from solution. Any directions you all can suggest???

Is it possible that under some operational conditions the whole cable assembly starts to oscillate? Could securing the sheath at various points along its length fix the problem?

Is it possible that under some operational conditions the whole cable assembly starts to oscillate? Could securing the sheath at various points along its length fix the problem?----

Hi Randall

I need to share with you one thought.

While we apply load to the driven while having cable without sheath, the cable tends to twist along a helix (helixing phenomenon (you refered oscillation)) and the entire cable tends to move towards one direction. The sheath also needs some flexibility to accomodate such a helixing and the sheath should rearrange itself to such a position where the cable finds the optimum running path.

If we fix the sheath, cable may get stressed for not allowing it to move to path of least resistance.

Can you please justify this with respect to your question..

First: let me say that I have no knowledge or experience in this field, so, apologies if I am talking rubbish.

It seems to me that the helixing is a "sort" of standing wave (with a high "component" of resonance), and, is itself undesirable. Stopping it before it gets started by anchoring the sheath, may still help.

I think I agree, though the problem may even be a bit more static, ie it is present even at slow speeds. I think the bend in the flex shaft should be nice and constant other wise the torque is being transfered around a tight corner causing stress concentration at this point.