awake
Titanium
- Joined
- Jan 24, 2006
- Location
- Angier, North Carolina
A friend of mine has been asked to do some work on a hydraulic cylinder from the mast of a forklift. It is single acting, and there is no vent - but instead, there is some sort of bypass hole in the piston that apparently allows oil to pass from the bottom up to the top, and vice-versa.
We're both puzzled on how this works. When pressure is applied to the bottom of the cylinder, what keeps it from feeding oil into the top through the bypass hole, or what allows the piston to reach the top without getting stopped by the oil in the top? And likewise, when the valve is released to allow the piston to fall, oil is draining back into the reservoir ... but since there is no vent, oil must also be sucked into the top of the cylinder, right?
As my questions indicate, I am a total noob when it comes to hydraulics. My friend has a good bit of experience using cylinders, and is a very experienced machinist, but now in his retirement he is taking on repair work here and there, mostly from farmers and such, and repairing hydraulic cylinders is outside his previous experience.
If anyone can help us understand, or point me to some resources, I will be most grateful, so grateful that I will reward you with - wait for it - a LIKE on your post!!
We're both puzzled on how this works. When pressure is applied to the bottom of the cylinder, what keeps it from feeding oil into the top through the bypass hole, or what allows the piston to reach the top without getting stopped by the oil in the top? And likewise, when the valve is released to allow the piston to fall, oil is draining back into the reservoir ... but since there is no vent, oil must also be sucked into the top of the cylinder, right?
As my questions indicate, I am a total noob when it comes to hydraulics. My friend has a good bit of experience using cylinders, and is a very experienced machinist, but now in his retirement he is taking on repair work here and there, mostly from farmers and such, and repairing hydraulic cylinders is outside his previous experience.
If anyone can help us understand, or point me to some resources, I will be most grateful, so grateful that I will reward you with - wait for it - a LIKE on your post!!