DIWA automatic transmissions for city and intercity buses
Economy and environment in focus: DIWA automatic transmissions for buses
Accelerate, shift, brake, shift. City bus operators face numerous challenges on the road each day. As a bus manufacturer or operator, rely on Voith’s globally successful DIWA automatic transmissions. With DIWA, you can benefit from intelligent shifting and reduced downtime, maintenance costs and fuel usage.
Today, over 400,000 city and intercity buses worldwide use a DIWA automatic transmission. Millions of passengers enjoy a more comfortable ride with less noise. At speeds that require other transmissions to shift two to three times, Voith offers you the benefit of stepless accelerating and braking.
Meets the needs of demanding BRT systems worldwide
The right transmission.
At the right time.
DIWA NXT
DIWA NXT is the consistent response to the growing demand for environmentally friendly drive solutions. Thanks to its hybrid system, the automatic transmission closes the gap to alternative drive systems and achieves fuel savings of up to 16%. DIWA NXT offers fleet operators and drivers a wide range of options in a solution that is efficient, comfortable and quiet.
DIWA NXT: Automatic transmission for all bus operation
DIWA NXT transmission with central recuperation unit
DIWA NXT is the next generation transmission for city and regional busses and coaches. It is optimized in terms of efficiency with a 2nd overdrive, a separate retarder and an optional Central Recuperation Unit (CRU) based on 48V technology to keep fuel consumption as low as possible.
The DIWA NXT is a mild hybrid system with various advantages. It is highly integrated into the flywheel housing of the engine and works with a specifically developed inverter, which is located on the top of the transmission to avoid line losses. A specifically designed battery and cooling system including an optimized DC/DC converter is available. The 48V mild hybrid system is developed specifically for buses and carries out various functions like stop-start, coasting, recuperation during braking procedures or even boosting-support. The new DIWA NXT is one of Voiths answers on the increasing demand for efficient and green driveline technologies and helps to bridge the gap between Diesel and alternative drivetrain technologies.
World-premiere: performance of differential converter and retarder can now be independently optimized
Recuperates braking energy based on a highly-integrated 48V mild-hybrid system
Reduces fuel consumption by up to 16%
Reduces air and noise pollution
Seamless hardware-software integration from one provider: Voith Digital Ventures
Central recuperation unit (CRU)
Benefits
The CRU is integrated into the flywheel housing
The CRU provides 25 kW of continuous power
Peak power from energy recovery stands at 35 kW
Liquid-cooled system
48 V motor with 300 Nm engine starting torque for all types of combustion engines
Integrated system with minimum possible additional axial length
CRU can replace up to two alternators
The CRU system enables active engine stopping/starting
Start-up assistance through active boosting
Reduces load on vehicle’s on-board electrical system thanks to recovered energy
Built-in frequency converter
Benefits
The frequency converter is integrated into the transmission housing. No additional space required for installation
High efficiency due to short cable lengths
Liquid cooled with water-based coolant
IP6K9K
ISO 26262
Electrical system
Wiring
Benefits
Wiring harness outside the transmission for easier access and reduced maintenance costs
Heavy-duty cables specially designed and suitable for the conditions in the engine compartment
Sensors easily accessible from the outside of the transmission
Hardwired sensors ensure perfect quality of electrical signals
Sensors
Benefits
Sensors easily accessible from the outside of the transmission
Directly wired sensors to ensure perfect quality of the electrical signals
Optimized torque converter
Benefits
Optimized torque converter for the start-up phase
Enhanced starting and climbing performance
Fully functional reverse gear mode
Independent of retarder function
Built-in secondary retarder
Benefits
Retarder functionality almost to a complete standstill
Better retarder control
Faster torque ramp-up
Optimized for cruise control
Second overdrive (7th Gear)
Benefits
Can now also be used for intercity and long-distance buses thanks to the second overdrive gear
Highest overall gear efficiency on the market
Best TCO thanks to lowest fuel consumption and maintenance costs
Additional comfort for passengers thanks to smoother engine speed adjustment to the driving situation
Lower noise emissions due to reduced average engine speed
Lower carbon and pollutant emissions thanks to optimized engine speed adjustment
Demo bus takes to the road on scheduled service
Success Story DIWA NXT
SUCCESS STORY DIWA NXT: DEMO BUS TAKES TO ROAD ON SCHEDULED SERVICE
With its mild hybrid system, the latest generation of our DIWA automatic transmission is closing the gap between diesel-only systems and other alternative drive technologies. And demand for these kinds of solutions above and beyond the pure internal combustion engine is steadily increasing. The reason for this is that to make further progress in reducing CO2, bus operators need to restructure their fleets substantially in the next few years.
Multi-week testing phase at OK.go As far as emissions are concerned, the existing engine concepts have largely reached their limits. At OK.go, a regional bus company whose services are an important component of the public transport system in the Ostalbkreis district on the outskirts of Stuttgart, the decision-making process for the switch is also already well underway. The multi-week testing phase of our demo bus, a combination of Iveco Crossway and our DIWA NXT, is an important part of this journey towards more sustainability.
For economic reasons too, it makes sense to store the energy produced during braking and decelerating. The electrical energy can then be used for pulling off and to supply the vehicle electrical system. This reduces fuel consumption as a result.
Whatever your requirements as a bus manufacturer or operator, with Voith you’ll find a suitable DIWA automatic transmission that lowers your fuel consumption and decreases your carbon footprint.
The DIWA.6 automatic transmission is the global standard for economically advantageous and sustainable city and intercity buses.
Together, intelligent acceleration management and need-based reduction of operating pressure reduce fuel consumption.
As a bus manufacturer or city bus operator, you profit from a dramatic increase in the transmission’s efficiency.
Better for the environment:
Our stop-start technology for your DIWA.6 transmission
City buses spend up to 40% of their operating time in idle mode. Tried and tested worldwide, Voith’s stop-start technology uses this downtime to greatly reduce fuel consumption and emissions. Do your part to combat climate change while making public transportation more attractive.
Proven in operation in more than 1,500 buses
Reduces fuel consumption by up to 12 %
Reduces air and noise pollution
Greater riding comfort for drivers, passengers, pedestrians and residents
Voith automatic transmission for buses - Comparison scheme of the DIWA functional principle
Specially developed for public transit buses, these transmissions are a must-have for economical operation: Reduced complexity and less installation effort for the manufacturer, lower fuel consumption and rock-bottom maintenance and service costs for the operator. And not only today - but for the entire service life of the bus.
Worldwide, bus operators large and small value the fuel savings made possible by Voith’s innovative DIWA transmissions. These transmissions have the ability to flexibly adapt to a range of infrastructure and topography specifications, which makes them usable in almost any market. This is especially true in emerging markets such as Africa, where the demand for public transportation is continually rising.
160000
160000
Current distribution of the 160,000 DIWA transmissions used worldwide
DIWA in bus rapid transit systems (BRT)
TransMilenio, Bogotá, Columbia – Market share Voith: 84 %
Since TransMilenio’s launch, driving times have dropped by 32% and emissions by 40%. The TransMilenio BRT system transports around 2 million passengers each day, making it one of the most efficient BRT systems worldwide. Today TransMilenio is considered a benchmark for many cities worldwide looking to introduce a BRT system.
Voith is a CNG-powered bus leader
Environmentally-friendly operations in North America
When phase two of the GHG regulations went into effect with the aim of reducing greenhouse gases in North American cities, there was a clear uptick in demand for climate-friendly CNG systems. Today, over 400 DIWA.6 transmissions are used in CNG engines throughout North America – a number that keeps on growing.
Establishing a modern transportation system in Baku, Azerbaijan
For the first European games in Baku in 2015, 300 new buses to transport fans were equipped with Voith’s DIWA.5 and DIWA.6 automatic transmissions. This marked the start of the city’s modern public transportation system.
Further quality power train products from Voith
Drivetrain Excellence - Voith Electrical Drive System for buses
The perfect drive system for changing intra-urban mobility: As an established system supplier with many years of experience and a partner to the bus industry, we have combined our comprehensive know-how in the fields of drive systems and E-mobility. Voith has developed a pioneering electrical drive system for local public transit. The Voith Electrical Drive System (VEDS).
