Gas-charged accumulators are a common feature of modern hydraulic systems. They carry out numerous functions, which include energy storage and reserve, leakage and thermal compensation, shock absorption and energy recovery. But while accumulators present a number of advantages in hydraulic system operation, and can provide many years of trouble-free service, they are a maintenance item.
For example, the correct gas pre-charge pressure must be maintained for proper functioning and optimum service life. And periodic inspection, testing and certification can be required by law, because hydraulic accumulators are pressure vessels.
To get a proper prospective on this issue, a hydraulic accumulator … continue reading »
A recent client consulted me about the failure of an axial piston pump. And based on my long experience working in hydraulic repair shops, the mode of failure was unusual. In fact, it was a type of failure I’ve never seen before. The slipper of just one of the 9 pistons had split clean in half–see inset pic. The other 8 piston slippers were in perfect condition. Normal ‘lift’ between piston ball and slipper socket, no signs of rolling onto their edges, no sign of been hammered onto the swash plate, retaining plate undamaged. Maybe you’ve seen this type of … continue reading »
One of our members wrote me this question:
“One of our customers has a new wheeled excavator. The auxiliary circuit on this machine is controlled by an electronic proportional foot pedal which sends its signal to an ECU and this ECU then sends a variable voltage to 2 proportional solenoids located on auxiliary circuit sandwich on the main DCV. But the operator dislikes this foot control of the auxiliary circuit and would like to have it controlled by ON/OFF switches on the joysticks. Luckily enough, this new machine has pre-installed electric circuitry which enables simple ON/OFF control of whatever function … continue reading »