A recent client asked me to investigate and solve a recurring problem on a diving bell launch and recovery system. The system comprised a hydraulic power unit, a bell winch, an umbilical winch and a guide-wire winch.
To launch the bell, the guide-wire winch is used to lower a clump weight to the seabed. The guide wires prevent the bell … Read more
I was recently engaged by a client to conduct failure analysis on a large (and expensive) hydraulic cylinder off an excavator. This hydraulic cylinder had been changed-out due to leaking rod seals after achieving only half of its expected service life.
Inspection revealed that apart from the rod seals, which had failed as a result of ‘dieseling’, the other parts … Read more
As you’re hopefully well aware, an unrestricted case-drain line is essential on a piston-type hydraulic motor, whether it’s axial, radial or bent-axis design. But when it comes to gear designs: external, internal and gerotor, a case-drain line is generally considered optional. This is because these types of motors don’t have a large-volume case or sump like piston motors do. But … Read more