Timing belt conveyor from mk serves as load handling device

SEW-Eurodrive has established efficient and flexible processes to achieve its vision for Industry 4.0. SEW’s new design for automated guided vehicles at its main US location includes integrated timing belt conveyors from mk. These vehicles serve as mobile workbenches for mounting individual gearboxes.

Classic interlinked conveyor technology is the most efficient way to automate processes in mass production. In customised production, however, the requirements are ever-changing – with ‘lot size one’ being the key word. This is where the flexibility of automated guided vehicles can be put to good use.

At its American headquarters in Lyman, South Carolina, SEW-Eurodrive has built a flexible production facility that is optimised for precisely such custom production – where classic conveyor technology is combined with flexible workstations. The autonomous vehicles drive through the hall independently, picking up pre-assembled gearboxes from a belt conveyor and taking them to the workers, who can then continue mounting them on the vehicle itself as if they were at a mobile workbench.

The vehicle then travels to the next station and transfers the gearbox back to a belt conveyor. It is thus possible to mount individual gearboxes, with efficient and flexible processes.

Through its ‘MAXOLUTION System Solutions’ business segment, SEW offers scalable and future-proof system solutions in the field of mobile and rail-guided conveyor technology. As an overall solution supplier for automated guided vehicle systems, it focuses not only on the vehicles themselves but also on all the services associated with them, from system planning to commissioning and servicing.

The vehicles and system components are produced at SEW-Eurodrive’s headquarters in Bruchsal, Germany. Alongside SEW’s world-renowned modular system for gearmotors and electronic products, it also engineers autonomous vehicles based on an innovative modular technology and software system. This system makes it possible to configure individual vehicles while keeping complexity low.

“Our portfolio incorporates everything from low-rise vehicles with and without lifts that are often used simply to replace a forklift truck, to assembly assistance vehicles, right through to vehicles equipped with collaborative robots,” explains Aaron Bronner, engineer at MAXOLUTION and the person responsible for designing and developing the vehicles. “We often build custom vehicles that are designed for a specific application.” Just like the vehicles for the plant in Lyman.

Ideal load handling device

To autonomously pick up and then set down the gearmotors with a belt conveyor, the vehicles need an appropriately powered load handling device. “We had initially considered a chain conveyor that we could integrate into our vehicles,” says Bronner. However, working with the conveyor technology experts at the mk, the team found a better solution.

“We decided on a dual-line timing belt conveyor instead of a chain conveyor,” says Ulrich Klein, one of the field representatives at mk who assisted with the project. A timing belt conveyor is more economical and requires less maintenance than the chain conveyor in the original plan.

Furthermore, the timing belt has a higher carrying capacity than the chain. That also provides greater stability for the product on the vehicle, even when navigating sharp corners or making abrupt (emergency) stops. The ZRF-P 2010 timing belt conveyor from mk was the ideal solution for the project: it can safely carry the maximum load of 160 kg, and the drive variants available also allow for reverse operation (in both directions).

“The fleet of MAXOLUTION vehicles with integrated load bearing devices from mk plays an essential role in realising the vision for Industry 4.0 on site. The high degree of automation makes our staff’s work much easier,” explains Rainer Neufeld, corporate electronics manager and project manager for the AGV fleet in the USA. “The vehicles transport our gearmotor construction kits to various stations over a line of several kilometres every day. The precise and reliable transfer of the trays with the aid of the MK load handling device is a vital part of the process.”

Klein recalls: “We’ve already overcome some technical challenges in the project.” The way the solution was integrated into the vehicle meant that the motor was not allowed to produce any interfering external contours. In addition, space for the protruding gearbox output shaft had to be kept free between the two conveyor lines. The motor therefore had to be positioned between the lines and below the conveyor.

The mk designers were able to use a modified mk centre drive in this case. “After the initial inquiry, it took around two weeks for us to completely work out the specs for the conveyor and clarify the installation conditions in the vehicle,” says Bronner. “The process was really fast and the solution worked wonderfully. Since the mk conveyor is also modular in design, it was easy to adapt to its intended use and integrate into the vehicle.”

Because mk uses SEW drive technology as standard, integrating the drive was not a problem. The experts at MAXOLUTION programmed the controller and coordinated it with the overall system.

An unconventional aid

How did MAXOLUTION end up ordering the conveyors from mk? “That was a nice story,” says Bronner. “We had already purchased conveyors for another project from MK. That was over Christmas, and needed to be done very quickly.” And since their collaboration in that previous project went so well and so smoothly, Bronner turned to MK again immediately.

That comes as no surprise to Klein: “We foster good customer-supplier relationships and try to be the most reliable partner possible. That includes helping our customers in unconventional ways. Our high-spec modular construction kit means we have the right products for all kinds of tailored customer solutions.”

In the project to build mobile workbenches for the Lyman site, everything fitted together perfectly – with excellent communication and the flexibility to adapt the right product to the customer’s needs quickly.

Another benefit for ensuring good collaboration was the fact that the location was within easy reach of the mk North America subsidiary. That meant mk’s fitters were able to carry out maintenance and servicing work on site if required.

Shortly before the delivery of the belt conveyors, MAXOLUTION decided to install custom side rails for guiding the pallets. To do so, additional mounting points were required on the conveyor frame. Bronner recalls: “The conveyors needed some modifications due to some spontaneous changes in the project. That was really tight. Fortunately, it didn’t pose an issue.” The open T-slots on mk’s aluminium profile system allowed for additional nuts to be fitted.

Klein is impressed by mk’s modular system: “Things like these additional screw-on points often seem to be trivial. But small things like that often make the difference when it comes to easy and quick commissioning.”

Once the final collective acceptance testing was complete, the timing belt conveyors could be delivered to MAXOLUTION and integrated into the vehicles. A total of 27 AGVs are now in use in the assembly processes in Lyman, giving the workers at the production stations much greater flexibility.

Neufeld comments: “The new assembly plant at our main site in Lyman is now our ‘flagship’ in the USA and can be seen as the benchmark for other SEW-Eurodrive plants.”

Bronner continues: “Plans are already under way for another project at a different SEW site.” MAXOLUTION is potentially providing the exact same vehicles with conveyors from mk once more. “I think we’ll be able to implement the project in the same way again, because the technology we need for it is already fully designed. We know it works, and we wouldn’t need to start from scratch again.”

This project shows how classic conveyor technology and cutting-edge automated guided vehicle systems combined make for more efficient process automation and more customised production. For SEW, projects like this one are another milestone on its journey to becoming the smart factory of tomorrow.