Rotary Vane Actuator - design assistance needed

[MalvernMike]

Howdy all. My name's Mike, from Malvern, England, and I'm glad to be a part of the forum.

I am designing a hydraulic rotary vane actuator to steer a 3-wheeler, rather than using traditional linkages. Each of the two actuators (one for each front wheel) will be connected to a hydraulic line, each connected to a linear push-pull piston, attached to the handlebars such that when the bars are turned, the two pistons push or pull fluid into the chambers, turning the wheels.

This is a new area for me, so I'd appreciate any advice relating to the matter.

The image shows how the design stands at the moment:

Currently I envisage the Cylinder Lids to be screwed or bolted down onto the Moving Outer Cylinder, and the Fixed Vane and Top/Bottom Supports to have machined splines so they are fixed, with a compression bolt to preload the bearings. I'm not quite sure how the Fixed Vane shaft should seal against the Cylinder Lids - the O-ring configuration shown here doesn't seem right to me.


I apologise for the lack of a direct question in the post - but I'm more asking for assistance in realising an efficient and reliable solution.

Thanks in advance for any help.

Mike.

Here is some related reading to Vane Actuators:

Service Manual for some existing rotary vanes

http://www2.emersonprocess.com/site...Shafer/Manuals/Rotary_Vane_Service_Manual.pdf

A research project into vane sealing

http://www.tribology-nikas.pwp.blueyonder.co.uk/project7.htm

 

[MalvernMike]

Hmm, the image didn't appear in the post and I can't see an edit feature..

Hopefully it will appear magically below:

 

[btrueblood]

The o-rings should have a seating groove in the cylinder lids. Google "Parker O-ring Handbook".

Vane actuators are prone to leaks around the vane seals. In rotating motors (more common for vane configurations) this is not as important, but in your case any leak past the vanes would appear (from your description) to result in misalignment of the wheels at worst, and poor centering of the steering arm at least.

You might consider a rack & pinion or scotch yoke 2-piston actuator in place of the vanes, those designs while possibly bulkier have a much more straightforward sealing arrangement.

Good luck!