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 50% less shifting and reduced downtime, maintenance costs and fuel usage.
Today, over 300,000 midsize, 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.
- Lower fuel consumption
- Reduced air and noise pollution
- Maximum comfort for passengers
- Low maintenance costs
- Lower installation effort
- Global market leader in CNG buses
- Meets the needs of demanding BRT systems worldwide
Driven by Efficiency
DIWA NXT: Automatic transmission for all bus operation
DIWA NXT is the next generation transmission for city, suburban and coach buses. 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)
- The CRU is highly integrated into the flywheel housing
- The constant power of the CRU is 25 kW
- The recuperation performance is 35 kW peak
- Liquid cooled system
- 48V-motor with 300 Nm starting torque for all kind of combustion engines
- Highly integrated system with minimum additional axial length
- Replacement of alternators by the CRU possible
- The CRU system allows active engine stop/start
- Excess recovered energy from the CRU can be used for boosting
- Additional the CRU system can supply electrical consumers
- Coasting available
- Wiring harness outside the transmission for easier access leads to a reduction of service costs
- High-durability cables designed and qualified for conditions in the engine compartment
- Sensors easily accessible from the outside of the transmission
- Directly wired sensors to ensure perfect quality of the electrical signals
Second overdrive (7th gear)
- Application range enhanced to intercity and coach application due to second overdrive
- Largest overall transmission spread in bus market
- Best TCO due to minimum fuel consumption and lowest service costs
- Additional comfort through second overdrive
- Lower noise emissions due to reduced average engine rpm
DIWA.6 und DIWA.5 automatic transmission
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 by up to 5%.
As a bus manufacturer or city bus operator, you profit from a dramatic increase in the transmission’s efficiency.
Your benefits at a glance
- Optimized fuel-efficiency
- Lower air and noise pollution
- Maximum passenger comfort and safety
- Tried and true stop-start technology
- Lower maintenance and installation costs
- High degree of reliability and availability
As a bus manufacturer, choose the compact DIWA.5 without external pipes or tubes, and easily install it in the most confined spaces.
Your benefits at a glance
- Great value
- Low wear
- Enhanced comfort for passengers and drivers
- Reduced thermal load of the cooling circuit
DIWA product features
Do you wanna learn how the DIWA automatic transmission works in detail? Check out our Voith Youtube channel.
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
- Software for easy updates
The intelligent path to even lower fuel consumption
The TCU’s software is also developed in-house at Voith. It upholds the highest security standards and protects the unique DIWA function our customers look for.
SensoTop’s abilities have been proven in countless applications worldwide. Depending on topography and vehicle application, real-life potential for fuel savings have been up to 7% compared to an optimized, acceleration-dependent shifting program.
The tried and tested diagnostic tool for all DIWA generations enables detailed diagnostics of the transmission and its components. Error data can be read out, and operating data analyzed and interpreted. This aids optimization and power train design.VOITH DIWA SERVICE
This telemetry solution is for bus fleet operators seeking to lower the TOC and downtime of their fleet, with minimal effort.
The system transmits the latest status data to responsible parties, keeping fleets up and running according to the health of the components.VOITH DIWA SERVICE
For operation managers in local puplic transport who have to reduce operational cost (fuel consumption as a major cost driver), our OnEfficiency.SmartAccelerate is a software configuration upgrade for your DIWA transmission, which helps to reduce significantly and sustainably fuel consumption.VOITH DIWA SERVICE
Questions? We are here to help.
International DIWA references
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.
DIWA in bus rapid transit systems (BRT)
– 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.
– Market share Voith: 63 %
The Brisbane Busway BRT system exemplifies how DIWA transmissions and services, as part of DIWA Excellence, increase driver comfort and overall safety. Using CNG (natural gas) also helps considerably reduced emissions from the start.
– Market share Voith: 89 %
In Hangzhou, a service and maintenance contract with predictive maintenance ensures maximum availability and cost transparency for the operator and stakeholders. Driving time is reduced by 40%. Separate bus lanes dramatically help reduce the number of traffic accidents. Based on these findings, Hangzhou has expanded its BRT system to include two additional bus lines.
– Market share Voith: 100 %
The integrated DIWA SmartNet concept used in the Zhengzhou BRT system enables predictive maintenance and analysis of operating data in real time. Complete integration of Voith’s ECU data in the operator’s fleet management system considerably reduces system complexity.
Voith is a CNG-powered bus leader
Environmentally-friendly operations in North America
Establishing a modern transportation system in Baku, Azerbaijan
Our Service - Part of Your Business
Made-to-measure service from Voith
Our customers benefit from our years of experience in developing and manufacturing key components for buses. Our accomplished bus experts know exactly what’s required for the success of bus manufacturers and operators.