Travel comfort in Japanese high-speed trains massively enhanced by Moog electromechanical actuators.
High-speed trains use a system to influence vehicle tilt or "vehicle sway" as well as to dampen vibrations. Without this, every passenger would be pressed into the seat by centripetal force when negotiating curves, which is perceived as unpleasant and not very comfortable. The same applies to vibrations in the carriage. Until now, various Japanese railway operators have only used a semi-active sway control system in their trains, which relies on a variable oil damper.
When the East Japan Railway Company decided to increase the top speed of its Shinkansen trains to 360 km/h, the basic tuning of the system no longer worked: the engineers had to apply more force over a wider frequency band to reduce vibrations and swaying for the passengers again.
This could no longer be achieved with previous technology, especially when it comes to continuously improving the comfort and stability of high-speed trains in addition.
Up to 50% less commuting
Moog is helping East Japan Railway Company in this task by providing electromechanical actuators, planetary roller screws and drive systems for the active tilt control system of the E5 and E6 train series. The all-electric system reduces sway by up to 50 percent compared to conventional pneumatic and hydraulic solutions.
At the same time, a Moog "Electro Mechanical Actuator" (EMA) is more responsive and provides higher forces. In parallel, the compactness of the housing for the control system was a decisive factor in the operating company's decision to work with Moog again.
In addition, electromechanical systems require considerably fewer components. The replacement of old oleopneumatic pendulum controls thus results in higher reliability and drastically reduced maintenance requirements.
Function in detail
As soon as an accelerometer detects lateral swaying/tilting of a train car, whether due to the rails, air flow or other factors, the current systems immediately calculate the necessary force to counteract the movement. This information is immediately sent from the controller to the Moog motor in the EMA, which implements this quickly and accurately. Each wheelset in the train (i.e. the bogie or chassis with two axles, four wheels) has an EMA and a passive damper to dampen lateral sway or vibration.
At the heart of each EMA unit is a Moog roller screw. These screws provide exceptional mechanical rigidity and motion precision thanks to the number of contact points between the rollers and the lead screw. This allows the actuator to carry heavier loads than conventional linear actuators, which are larger and often have overheating problems.
"Moog prides itself on being technology neutral because we have deep expertise in all the strengths and weaknesses of different motion technologies," says Enrico Bagnasco, Product Content Developer at Moog. "This is absolutely critical when choosing a partner to help a company move from one technology to another. Our long-standing relationship with Japan Railway East and the continued success of Moog products on board their trains proves this beyond doubt."