Correct, that's what I'm doing. Basically the output shaft continues to 3mm from the seal (inside the end cap the screw goes into) and has a bore down the center so when the screw is 40mm in (and the output piston has only moved 5mm) there's somewhere for the screw to be. If I didn't need it to resist huge bending loads the whole thing could be much shorter
Ah the device needed to be ultra compact and portable, fit in a pocked kinda thing. Good idea though, I'm playing with hydraulics a bit lately I might make a grease-gun powered something
Yes, very much so. The first tests I did (unit worked with amusing caveat: lip seal worked so well it wiped ALL of the extreme pressure lube off the screw (lapped thread + thermoformed thread in seal = perfect wiper) and the thread cold welded to the cap after about 1500kg of force on the ramc, it just stopped turning dead, then snapped and left the chunk in the cap, fully stuck together even after the whole unit was disassembled... need to make screw out of dissimilar metal) I had heavy leather gloves on for that reason. It's a one off but before it gets used in the field I'd add protection around the base for such a failure.
Very cool idea. Curious to see/hear more about your usecase.
The input screw could extend all the way inside the piston telescopically, with fluid between them, and still work. Or is that what you're doing?
Correct, that's what I'm doing. Basically the output shaft continues to 3mm from the seal (inside the end cap the screw goes into) and has a bore down the center so when the screw is 40mm in (and the output piston has only moved 5mm) there's somewhere for the screw to be. If I didn't need it to resist huge bending loads the whole thing could be much shorter
For a one off application, a decent grease gun will make 10000psi and save you having to make that fancy seal ?
Ah the device needed to be ultra compact and portable, fit in a pocked kinda thing. Good idea though, I'm playing with hydraulics a bit lately I might make a grease-gun powered something
Interesting, thank you for sharing with us
Very cool!
When your lipseal fails is there a risk of injection injury?
Yes, very much so. The first tests I did (unit worked with amusing caveat: lip seal worked so well it wiped ALL of the extreme pressure lube off the screw (lapped thread + thermoformed thread in seal = perfect wiper) and the thread cold welded to the cap after about 1500kg of force on the ramc, it just stopped turning dead, then snapped and left the chunk in the cap, fully stuck together even after the whole unit was disassembled... need to make screw out of dissimilar metal) I had heavy leather gloves on for that reason. It's a one off but before it gets used in the field I'd add protection around the base for such a failure.