Piston ring trouble

[g0ggs123]

Does anyone have experience of calculating piston ring leakage, my problem is that the piston leakage is in a hydraulic system with a flooded cylinder and operating pressures of up to 400bar. All journals I find are on IC engines and so the theory is very different.

There are also differences in piston config, the piston I am looking at has one ring whereas a IC engine piston has numerous piston rings designed to do different things.

So, anyone know how to work out the pressure distribution against the cylinder wall and also if it is possible to relate fluid mechanics at such high pressure where leakage is at fairly high velocity, basically the fluid is getting blasted through the split line in the ring.

Cheers
Gordon

[nucleus]

Hydraulic System Analysis by George R. Keller, P.E. published by H&P has some information. It contains some formulas but without the background information they are not much use. It covers about 3 pages with graphs etc so it is too much to type. You may be able to borrow a copy from a library or if you want to buy a copy it’s available in their bookstore at:
http://www.hydraulicspneumatics.com/default.aspx

The book does not give dimensions for seal lands. Maybe Parker Hydraulics has a design handbook for these seals because they have a lot of information available. Like ICE’s the pressure helps to seal the fluid.