Cylinder Rod End Condition
Cylinder Rod End Condition
(OP)
I am designing a cylinder rod to be used in transmitting fluid at pressure. I've attached a picture that described what we have.
We are column loading a cylinder rod and I wanted to seek advice on the "K" value end condition constant.
The cylinder piston is fixed on either end but when extended by about 25" looks pretty slender. An O-Ring retains the pressure and a short rod bearing is used to somewhat keep it straight.
On the column loading of the rod, does anyone think I can use K=1 for the end condtion. Does the rod bearing provide enough support to justify K=1.
The cylinder rod is basically a hollow tube within a tube.
We are column loading a cylinder rod and I wanted to seek advice on the "K" value end condition constant.
The cylinder piston is fixed on either end but when extended by about 25" looks pretty slender. An O-Ring retains the pressure and a short rod bearing is used to somewhat keep it straight.
On the column loading of the rod, does anyone think I can use K=1 for the end condtion. Does the rod bearing provide enough support to justify K=1.
The cylinder rod is basically a hollow tube within a tube.





RE: Cylinder Rod End Condition
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Cylinder Rod End Condition
It doesn't seem very prudent to put a sketch that doesn't give enought information for someone to make an engineering judgement on an internet website and solicit opinions from strangers. Give a better description of the guiding for the load and cylinder. Explain your forces, etc. by doing this you might even answer your own question.
I think your seals may fail due to rod deflection at the rod seals before the column will have problems. Can you design for a longer length of rod to remain inside the cylinder to act as a stop-tube?
RE: Cylinder Rod End Condition
I'd be inclined to fix one end of one of the tubes, e.g. by screwing it against a shoulder, or bolting an integral flange to a face.
Mike Halloran
Pembroke Pines, FL, USA