Temperature-resistant pneumatics for Swiss pantographs
It’s one of those questions children ask that fathers first have to check Wikipedia: how does the power supply to electric trains work? Tip: give a meaningful look and provide a convincing answer: “That's the work of the pantograph.” This may be the right technical term, but Wikipedia will first lead you to believe it is a geometric drawing instrument. The simplest solution: This article will provide all the important facts.
To explain this question on power and trains, AVENTICS interviewed Hanspeter Jutzi, CEO of Swiss company Richard AG in Murgenthal. “We have developed and produced pantographs, main circuit breakers, insulators, and many other components for modern traction vehicles for 111 years,” says Hanspeter Jutzi. And AVENTICS valves, cylinders, and air preparation systems are all on board.
These Swiss pantographs press the carbon strip up onto the live overhead lines. “Unlike with the simple streetcars from decades ago, modern rail cars feature complex control electronics and require a continuous power supply,” explains Hanspeter Jutzi, manager of around 80 employees. “The challenge lies in reliably maintaining the contact between the carbon strip and the line but not pressing against the overhead lines too strongly because they will otherwise wear too quickly or even rip.”
In the Richard pantograph, this is performed by a pneumatically controlled rocker, similar to the joint in your knee. The pneumatic solution from AVENTICS consisting of an valve, precision pressure regulator, pneumatic bellows actuator, and air preparation presses the carbon strip against the overhead line with three bars of compressed air. This corresponds to a force of 70 to 85 N. This pneumatic force is enough to maintain the contact with the overhead line, even if the track is uneven.
In Europe, trains can also cross borders without issues. With alternating current, the carbon strip contacts can absorb 25,000 volts with maximum currents of up to 900 amperes and transfer them to the train. Richard pantographs are approved for speeds up to 230 km/h, proof of just how dynamic pneumatic control solutions are.
“We require an extremely wide operating temperature range of -25°C to +45°C from the pneumatic components, and in some cases even more extreme values for train operators in certain climatic regions,” emphasizes Hanspeter Jutzi. The pneumatic solution from AVENTICS is robust not only when it comes to temperatures: compared with electromechanical solutions, it is virtually wear-free.
AVENTICS supplies the pneumatic assembly for the pantographs and other modules from Richard right to the Swiss family-run company 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,” states the CEO. “We know that our customers still expect original spare parts years later, and that’s how we choose our suppliers.” AVENTICS, also a certified supplier established for decades and involved with numerous operators, meets all of these requirements.