A highly qualified, intensive care doctor is struck down with appendicitis. So he undergoes keyhole surgery at the hospital where he works. He is now a patient in his own hospital. In the recovery room, post surgery, he is awake but starts to feel light headed. A nurse takes his blood pressure and it’s way down. This triggers an emergency response.
The medical emergency team arrives at the patient’s bedside. Being a doctor himself, the patient argues with them. He can’t believe he’s having a heart attack, because he doesn’t have any chest pain. But the attending emergency doctor shows … continue reading »
While absolutely essential on a piston-type hydraulic motor, an external case drain line is usually optional on gear motor designs–external, internal and gerotor/geroller. These types of motors don’t have a large-volume case or sump like piston motors do. But they do have internal leakage which by design, usually accumulates in a small cavity just behind the shaft seal.
By installing a high-pressure shaft seal and two check valves as shown in the schematic diagram inset above, internal leakage is drained via the return line–something that’s not acceptable for a piston motor or pump!
So the presence of a high pressure … continue reading »
This issue is particularly important in corrosive environments, such as marine or offshore applications. And even more so if the cylinder rod is finished with conventional, hard chrome plating, which due to its micro porosity, has relatively poor corrosion resistance. The BEST way to keep the surface of the cylinder rod protected, is of course to park the machine with all of the cylinders fully retracted. But this is not always possible. And even if it is, if the cylinders are gravity loaded when fully retracted, it’s possible they will extend over time, exposing the rod.
One solution that’s extremely … continue reading »