Description

“The RX 70 Hybrid – Saving energy has never been easier”
The new RX 70 Hybrid sets standards: It combines high turnaround performance and ecologic responsibility in a unique way and it is the first hybrid truck produced in series with energy recuperation. When braking the kinetic energy from the movement of the truck is converted into electric energy which is stored in “Ultracaps” and reused when the truck accelerates again. This reduces the energy consumption and CO2 emission alike and makes the RX 70 Hybrid the most fuel efficient truck of its class.
This has been awarded with a prize: On November 22, 2012 STILL was awarded the Federal German Eco-Design Award in the category “product” for the RX 70 Hybrid for its outstanding ecologic design that covers the whole life cycle by the Federal Ministry of Environment.

Innovations

The RX 70 Hybrid leads the balance between ecology and economics into a new era. The truck was designed on the basis of the successful RX 70 series and is worldwide the first diesel truck with energy recuperation and electric power transmission.
The new RX 70 is a real hybrid: It combines two types of propulsion and two energy storage systems. The internal combustion engine generates electric power for the drive motor with a rotary current generator directly connected to the IC engine. All the components of the drive system are connected by the power electronics that also controls charging and discharging of the additional energy storage.
Besides the diesel tank the truck is fitted with so called Ultracaps. These high-performance double layer capacitors are charged with the energy which is released when the truck brakes. When accelerating the energy from the Ultracaps is added to the energy provided by the internal combustion engine to propel the electric drive motor. The electric energy storage is one of the major components of the hybrid truck. This is where the recuperated energy is stored.
Opposed to its predecessor the new RX 70 Hybrid does not only consume less fuel, it also emits less noise. This is achieved by reducing the engine speed. The additional energy provided from the Ultracaps and the corresponding reduction of the workload of the IC engine also reduces CO2 emission compared to the RX 70 by up to 20%.

Market relevance

During the concept development phase of the RX 70 Hybrid STILL concentrated on several important characteristics of the truck. A major focus was placed on improving efficiency. The target to substantially reduce fuel consumption while keeping the turnover capacity at identical levels was to be achieved by implementing the innovative hybrid drive.
Besides this, STILL aimed to improve the service friendliness of the truck by extending the maintenance and service intervals. The major drive for this was to use the new hybrid drive in order to reduce the workload of the internal combustion engine. The lower engine speeds positively affect the wear level of the parts. Apart from this it was planned to deploy wear free double layer capacitors in the Ultracaps. The goal for the RX 70 Hybrid also was to balance economics and ecology – one of the guiding principals for STILL GmbH. Using recyclable materials was just as important for this as was the reduction of noise emissions and the fuel consumption with the corresponding cutback in CO2 emissions.

Customer benefits

Economy: In demanding applications, the RX 70 Hybrid reduces consumption by up to 20 % compared to the STILL standard truck. This roughly corresponds to 0,8 litres of diesel per hour of operation. The energy recuperation during braking reduces the workload of the internal combustion engine by about 30 percent when accelerating. The service friendliness of the trucks is also of great importance, because it has an additional effect on the economic feasibility of a truck. The contribution of the energy stored in the Ultracaps when accelerating reduces the speed of the IC engine by approximately 6 %. This reduces strain of the IC engine. Consequently service and repair costs for replacement parts are reduced. Apart from this the capacitors in the Ultracaps are not subject to wear. Service times and service costs are minimised indirectly improving the efficiency of the truck.

Environmental friendliness: Using the recuperated energy when braking increases the energy efficiency. Also, optimising the control of the IC engine greatly reduces pollutant emissions. For example, the CO2 emission is decreased by up to 20% (VDI 2698). Slowing down the engine (by 200 rpm) when lifting and when driving significantly reduces noise emission thus making another contribution to protecting the environment. Beyond this, about 95% of the materials used in the RX 70 Hybrid can be recycled.