Flexible cable carrier in a confined space for dynamic X-ray robots

• What was needed: twisterchain®
• Requirements: The cable guide had to have a low installation height and the smallest possible outer diameter. It also had to be able to carry a large number of different media.
• Industry: medical equipment
• Success for the customer: The twisterchain® allows all cables to be guided whilst the small installation space is maintained. The new system saves weight so there is less strain on the robot.

A cable guide was to be developed for this medical X-ray system based on a robot. In addition to a robot for patient positioning, the X-ray robot is part of a complete system for cancer therapy using particle beams from Siemens. The robot hangs from the ceiling and guides an X-ray C-arm. The robot base frame was removed because ceiling height was limited. The X-ray components and the robot energy supply system were raised so that the robot's range of motion was not restricted, but the overall height was reduced to a minimum. Here it was important to ensure that the outer diameter was kept as small as possible so that there was no collision between the robot and the cable guide. The cable guide design had to accommodate a variety of media.

The pioneering approach was using a twisterchain® of type 4008.15.250/850, but not in the usual way (with stationary lower run and movable upper run). Because of the robot's ceiling mounting, the twisterchain® has a stationary upper run and moving lower run. Chain support for a rotation range of +/-100 degrees must therefore move along with the upper run. Another special feature is that two reverse chains are used. This allows all the necessary media lines to run through the cable guide. The number of media and cables exceeded the total weight the robot can carry, so the cable guide was designed to be self-supporting.