Chassis and drive system of the RT
In 2018, we found the ideal partner for the electric power train in Volvo Penta. Volvo Penta, as a subsidiary of the Volvo Group and long-term partner of Rosenbauer through the supply of D16 engines for PANTHER ARFF vehicles, has access to the know-how of the Volvo Group, whose e-fleet now consists of more than 4,500 buses and who, with the FL and FE Electric, is considered one of the pioneers in the electric truck sector. And it is their modular system from which we obtain all high-voltage components, such as the batteries, the e-machines, and the power electronics and control units, including a cooling system that has been especially developed for Rosenbauer.
Energy when it matters
BMW also has a longstanding partnership with Rosenbauer: the first generations of the FOX portable pump were powered by BMW Boxer engines. A special development partnership with BMW was started for the CFT in 2014, with a 6-cylinder passenger car diesel engine with 3 l displacement and 200 kW output being utilized as a range extender. We had a strong desire to incorporate this high-performance engine into the series development, and concluded a series supply contract for B57 engines from the BMW plant in Steyr, thus allowing us to continue our successful development cooperation with BMW.
The energy from the range extender drives a generator from the Volvo modular system via a transfer case, and it is also connected to the water pump via the very same. The pump can therefore be driven either electrically or mechanically. We opted for Rögelberg for the development of this intelligent gearbox, not least because of the German gearbox manufacturer’s extensive expertise and high level of vertical integration.
But the strongest drive is useless if you can’t transfer the power to the road. As with the CFT, an independent suspension was used for the series development. This was successfully implemented with our long-term supplier Kessler. Kessler was also responsible for developing the differentials and the two-speed transmissions on each axle.
A hydropneumatic suspension was tested in the CFT. For the series development, we wanted to meet customer requirements for the level regulation as exhibited by the CFT, but the technology needed to be simpler and more maintenance-friendly. US-based company Hendrickson had the right solution in the form of robust pneumatic cylinders that allow the vehicle to be raised and lowered, providing ground clearances from 175 mm to over 350 mm.
The vehicle, which weighs up to 18 tons, also needed a way to slow down! Although the use of multi-stage adjustable recuperation is usually sufficient in flowing traffic, there is always a situation where the braking performance is crucial. In this respect, Knorr-Bremse, with its pioneering technologies (ABS, ESP and ADM), is the right development partner for our production-vehicles. Right from the very first test drives, we were impressed by the high braking performance and controlability.
In order to meet the functional safety requirements of ISO 26262, the decision was made to choose a partner whose electronic components are certified accordingly. We found this partner in TTControl, the manufacturer of electronic control units specializing in mobile machines, with whom we also implement the necessary content for successful certification of the entire vehicle in accordance with ISO 26262.
Alongside the PANTHER, the AT, the ET, and the AVENGER, moodley was also responsible for the design of the CFT. For the series development, an even more functional concept was implemented, in order to meet all standards and laws. The challenge was to not sacrifice any of the ergonomic advantages of the CFT. And, to the contrary, especially in the design of the interior, many findings and suggestions for improvement from the CFT were successfully implemented in the RT.
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