Pressure in double-bellows linear actuators from AVENTICS automatically compensate for varying distances between the vehicle and overhead wires to maintain constant force applied by the conductive strip.
This pneumatic solution from Aventics consists of a valve, a pressure regulator, the bellows actuator, and air filtration units. The regulator maintains pressure in the bellows consistently at 3 bar (44 psig), which corresponds to a force of 70 to 85 N (16 to 19 lb). applied by the carbon strip. This force is enough to keep the carbon strip in contact with the overhead line, even when the track is uneven.
In Europe, trains can also cross borders without issues. With alternating current, the carbon strip contacts can absorb 25,000 V with maximum currents of up to 900 A and transfer them to the train. Richard pantographs are approved for speeds up to 230 km/hr, proof of just how dynamic pneumatic control solutions are.
Components Must Be Robust
“We require an extremely wide operating temperature range of −25° to 45° C (−13° to 113° F) from the pneumatic components, and in some cases even more extreme values for train operators in certain climatic regions,” offers Jutzi. The pneumatic solution not only tolerates these wide variations in temperature but is virtually wear-free when compared to electromechanical solutions.
Aventics supplies the pneumatic assemblies for the pantographs and other modules pre-assembled. “We may only be a medium-sized enterprise, but in some cases we have worked with rail vehicle manufacturers and operators for decades,” adds Jutzi. “We know our customers still expect original spare parts years later, and that’s how we choose our suppliers.”
This information was submitted by John Bridges, head of marketing, Aventics Corp., Lexington, Ky.