Without a doubt the overriding theme at bauma 2019 among construction-machine builders and component suppliers alike is digitization. Most mobile-hydraulics engineers are well-aware of the possibilities: Digital machine management, data storage in the cloud, telematics, software and apps, electrohydraulic controls, ubiquitous sensors, and so on – these are clearly becoming the new standard building blocks in the construction-equipment industry.
The goal of all of that is answering questions that range from where is my machine located and how many hours has it run to why is my filter displaying error codes and what maintenance measures are needed? But digitization isn’t just about component and machine control, it is also helping drive efficiency gains and with it, fostering improvements in sustainability.
There is certainly a push for more-efficient “traditional” systems at bauma. For instance, there’s a heightened interest in compact equipment that works in restricted spaces, such as in urban settings. To do more with less, hydraulics manufacturers are refining system performance with embedded sensors and controls, upping pressure limits, revamping sealing systems to prevent leaks and even turning to high-efficient hydraulic fluids that don’t easily break down when stressed.
There is also more interest in recovering and reusing energy, rather than turning it to wasted heat. Some companies are advancing so-called hydraulic batteries, systems on mobile equipment that rely on accumulators in regenerative systems. For example, Sennebogen is talking about the advantages in its new machine being unveiled at bauma, said to be the largest material handler ever built.
It weighs approximately 390 tons and has a reach of up to 40 meters. It is equipped with an energy recovery system that consists of an additional hydraulic lift cylinder and several gas accumulators. Each time the boom lowers, the energy recovered from the cylinder is temporarily stored and is available for the next lift. This system reportedly offers energy savings of up to 30% compared to conventional drives.
Another major trend emerging at bauma is that construction-equipment manufacturers are increasingly considering alternative drives – which might have major ramifications for the fluid power industry. For instance, there is a growing interest in hybrid vehicles. Such systems can use batteries or other electric inputs to handle light work and then engage a combustion engine where maximum power is required.
Keestrack is presenting its new B7e jaw crusher at bauma. The hybrid system uses a 55 kW electric motor to drive the working hydraulics for the track drive system, hoist cylinder, vibrating feeder with double-deck primary screening and all conveyor belts. It relies on plug-in operations served by the power grid or an additional generator. The company says energy savings of up to 80% are possible.
Even more far out, the company’s engineers will showcase a solar-powered tracked stacker. Photovoltaic modules span the 23-meter long conveyor belt and a battery array housed in the chassis stores the electrical energy. The conveyor belt and caterpillar track are directly electrically driven while an electric-driven pump supplies the lifting hydraulics. Connection to the grid or diesel generators provides back-up power.
But the real wake-up call for hydraulics is the interest in totally electric drives, especially for smaller machines. Let’s face it, the construction machinery industry is under increasing pressure to prevent polluting exhaust emissions, as some regulations will demand either zero-emission or ultra-low emission vehicles in the not-too-distant future. The increased use of electric drives could be one way of achieving this aim. Companies like Volvo have been pioneering the evolution for a number of years and has shown concept vehicles, and others exhibiting at bauma, such as Komatsu, Mecalac, Bobcat and Bosch Rexroth are expressing interest.
A number of companies will be showing prototypes or upgrading smaller machines in the lower power range with electric drives – totally eliminating hydraulics. We’ll report on whether they are practical or just novelties, and where the technology is headed.