Electric mixer drum drive for construction site

The electrification of construction machinery does not necessarily involve complete vehicle concepts. In many cases, it starts with individual functions that can be specifically optimised.

One example of this is the electric drive for mixer drums, as presented at Bauma. The focus here is not on the journey to the construction site, but on operation directly on site. The approach is clearly delineated: Existing systems are not replaced, but supplemented. This allows specific work processes to be changed without having to redevelop the entire machine architecture.

ZF Friedrichshafen EcoMix CMI as an electric mixer drum drive

With the EcoMix CMI, ZF Friedrichshafen is presenting a solution based on familiar components. The system combines a standard gearbox with a reduction stage and an electric motor. The result is an electric drive that is specially designed for mixer drums. The technical design is aimed at drum sizes of ten to twelve cubic metres. With a torque of 64 kilonewton metres, different types of concrete can be processed, from more fluid to firmer consistencies in the F1 to F5 range. The design shows that existing technology can still be utilised. Instead of a complete system change, the existing mechanics are supplemented with electrical components.

Electric operation when loading and emptying the drum

The use of the electric drive is limited to certain work phases. The diesel engine can be switched off during loading. In this situation, the electric motor takes over the movement of the mixer drum. The drum is also driven electrically during emptying. The combustion engine remains switched off. The decisive factor is that these processes take place directly on the construction site - i.e. exactly where emissions and noise are particularly noticeable. This targeted utilisation distinguishes the approach from comprehensive electrification concepts. It is not about continuous operation, but about individual, clearly defined processes.

Noise reduction and emission-free operation in use

A key effect of the electric drive is the reduction of emissions during operation. At the same time, noise levels are reduced as the electric motor is quieter than a conventional diesel drive. This difference is particularly relevant in sensitive areas of use. These include construction sites in densely built-up areas or in close proximity to residential areas. The technology makes it possible to carry out certain work steps more cleanly and quietly. The advantages can be summarised in concrete terms:

• no diesel operation during loading and emptying
• Lower noise levels during the work process
• Targeted reduction of emissions on the construction site
• Utilisation of existing mechanical systems

CMe drive integrated into existing vehicle technology

A central component of the system is the electric drive for the mixer drum, known as CMe. It is integrated into the existing overall system and works together with the existing components. The technical realisation does not require any fundamental conversion of the vehicle. Instead, the existing structure is utilised and expanded. This integration capability is crucial for practical application, as it reduces the effort required for customisation. The control system is designed so that electric operation can be activated in a targeted manner. This maintains flexibility in use.

Application logic for urban construction sites and future requirements

The use of electric partial drives results from the requirements of modern construction sites. While the use of diesel in road transport is becoming increasingly restricted, it often remains common on construction sites. This creates a contradiction that can be addressed technically. Electric solutions such as the EcoMix CMI address precisely this point and enable low-emission operation in sensitive situations. ZF Friedrichshafen is thus positioning itself in an area that is likely to become more of a focus in the future. The approach shows that changes can be implemented step by step - not through complete system changes, but through targeted adjustments to individual functions.