EPX - Energy Recovery Valve

EPX concept, part of Walvoil’s Hydraulic Digital Solutions, innovates beyond the industry standard with a three-way compensation device that not only limits actuation speed but can also recover stored gravitational and kinetic energy of the system.

EPX's approach combines two key innovations.

Meter-Out compensation

This design improves the control of unbalanced loads, proving compensation to the return flow. This innovation also simplifies the load control valves: in a meter-out system the compensator protects against load speed drifting.

The secondary valves are in this case used only as safety equipment. These safety valves, typically flanged on the cylinder, are designed to have minimal pressure drop and minimal impact on main valve operation.

Three-way compensation

This patented design introduces an extra flow path to the meter-out compensator. During operation, the compensator measures the fluid pressure: if the pressure exceeds a determined threshold, an extra path is opened, pressurizing the recovery line with the stored energy in the actuator.

Testing activities on wheel loaders have demonstrated a 20% of energy saving combining recoverable energy and reduction of compensation losses.

What are the advantages of the system?

• Flow Sharing repartition
• Energy recovery line
• Compensation of the unbalanced loads (drift protection)