A new cab conveyor system for tractor assembly has been installed at the John Deere plant in Mannheim. It transports the cabs safely from the feed point to the assembly locations, enables safe working under the suspended cab and then sets them down reliably. After 40 years in use, the old system had to make way for a new one. "One of the main reasons for the complete renewal of the electronics was the current requirements of safety technology," explains Hans Ziegler, project manager in work preparation at John Deere. "We already operate several systems with drive technology from SEW-Eurodrive. Our maintenance department is very satisfied with the technology from Bruchsal. In the event of a problem, the delivery of spare parts works smoothly. The service and cooperation work very well." SEW-Eurodrive also operates a close-knit network of Drive Centers and technical offices - always close to the customer.

The cabs are manufactured at the John Deere plant in Bruchsal and delivered from there to Mannheim. First, the cab conveyor system lifts them to the transport level. Here, the electric monorail system (EMS) from SEW-Eurodrive's Maxolution system solution program transports the cabins to a switch, which forwards them alternately to two parallel lines, allowing two cabins to be joined at the same time. From the transport level, the cabin is first automatically lowered to a pre-height at which nobody can be injured.

The operator now takes over with a hand-held control unit. He moves the cabin to the joining position and lowers it further. On the joining level, the drive units with motor, axles and hydraulics are ready for the operator cabs to be mounted on. The workers have to reach in and under the suspended cabin to attach electrical cables, hydraulic hoses and screw connections. The top priority for everyone involved in the project was to ensure the safety of the workers when working under the suspended cab.

The joining process and work under the suspended load are safeguarded by the new cabin conveyor. The high-performance Movisafe safety control system enables the cabin to be lowered onto the drive train by remote control. (Image: SEW-Eurodrive)

SEW-Eurodrive supplied the drive technology and the components of the safety system, including the most important sensors, individually represented by the Maxolution system solution EHB. Drive solutions close to the field, which require little space and are vibration-resistant, supply the geared motors. The two lifting drives, each with 5.5 kilowatts, are driven as a group drive by a Movipro-PHC with 11 kilowatts of rated power. A Movifit-MC controller supplies the travel motor with 0.55 kilowatts of rated power.

Conveyor systems with this type of decentralized drive technology are superior to comparable, centrally controlled systems. Thanks to the modular and parameterizable Movivision software solution, the engineering of such systems is very simple, including through simulated, virtual commissioning before the actual conversion of the system. For this reason, the actual commissioning times at the customer's premises can be significantly reduced. This important feature of the Maxolution system solution was also a key aspect in the conversion of the John Deere system.

A major challenge in the implementation of this project was the tight installation space in which the cabins are conveyed. (Image: SEW-Eurodrive)

All safety functions run on the Movisafe PFF-HM31 safety controller from SEW-Eurodrive. These include the safe position of the vehicles, safe lifting position and safe lifting speed. It controls the SBC (Safe Break Control) safety functions and ensures the correct distance between the vehicles. A mechanical distance sensor is no longer required. The high-performance Movisafe safety control system now enables workers to set the cabin down on the drive train by remote control while complying with all technical safety aspects (safe communication and position-dependent, safe speed / SLS and SLP in accordance with PL "d").

"The cabin conveyor leaves nothing to be desired in terms of occupational safety, control technology, maintenance and future orientation and even exceeds the requirements defined in advance," explains project manager Ziegler.

SEW project manager Bernhard Pehlegrim adds: "In addition to the technical parameters, we must not forget that the good cooperation between all parties involved was crucial to the success of the project."

Gunthart Mau/as