001 prosthesis shafts
Technical Report
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Robots with hip prostheses

Fully automated grinding and polishing of implants

Two articulated robots are grinding and polishing hip prosthesis shafts at Aesculap. In this complex process, each of them completes various work steps without putting down the implant between the steps. This fully automated process facilitates higher performance and reproducible quality and therefore higher economic efficiency than the previous, mainly manual handling process.

Aesculap has sent the staff members concerned to special grinding and polishing courses at the Kuka College at SHL in Böttingen to ensure flawless operation. "We do not discriminate between programmer and operator. The person at the machine has full responsibility," explains Robert Braun."The familiar Windows interface of the Kuka control panel facilitates handling of the robots.”

 

Intelligent solution from one source

The complete grinding and polishing system was designed and delivered by SHL Automatisierungstechnik AG. The Kuka system partner provided a turnkey-system and accepted responsibility for the whole process, including project planning. The know-how of Aesculap was integrated into the planning. The scope of the order included the two Kuka robots KR 30 HA including their PC-based controls, the gripper and gripper change system, the grinding and polishing stations, the measuring devices, the washing and cleaning components with the respective pastes, the palletting system and the safety devices. "The greatest challenge for SHL was handling the complexity of the process," emphasized Bern Schšndienst. "In this respect, the interface between robot and grinding system is particularly important."

The pneumatic grippers, which were developed by SHL for this application, were an essential requirement for the success of the project. The actuators have to maintain a firm grip on the hip prosthesis shafts, but may never damage them. The grippers were shaped to fit the parts, taking into account that the shafts are hot-pressed parts and therefore have certain tolerances. SHL validated the process during pre-tests at its own site.

 

Combinable competence

"SHL received the order, because it has competence in robotics as well as in grinding processes," explained Norbert Braun. "This know-how was optimally combined for our purposes. A further advantage is the geographical proximity. As soon as the test system was in operation, we could discuss important points on site and at short notice. It was therefore possible to clarify basic issues before initial operation and to commission the system from the manufacturer. SHL is furthermore a system partner of Kuka and as we have had good experience with several Kuka robots, we intend to focus on this supplier in future."

Increased productivity as well as reproducible and continuously high quality during grinding and polishing prove that Aesculap has chosen the right solution. The low space requirements of the robots are an additional benefit. Furthermore, the favourable price/performance ratio of the KR 30 HA made it possible to reduce the total investment required for the restructuring process.