Maintenance-free and lightweight plastic plain bearings in resuscitation device

The animax resuscitation device enables all rescuers, from amateurs to professionals, to perform optimal cardiopulmonary resuscitation (CPR Cardio Pulmonary Resuscitation). It is possible to perform perfect resuscitation over a longer period of time without tiring effort. The device is simply placed over the patient's chest and retracted until it touches the chest. Cardiac massage is performed by pressing the lever. The ventilation pressure is throttled and can be seen via a pressure gauge on the patient valve. A pressure relief valve and a spontaneous breathing valve have been integrated to protect the patient. It is also possible to connect oxygen to ventilate the patient. As the animax is also intended for non-clinical and semi-professional use, the device must fulfil many other requirements in addition to its actual functions: Freedom from maintenance, very fast set-up time, small dimensions and low weight for mobile use as well as an affordable price for aid organisations.
Bearing solutions in particular have been decisive here, as they are used at various points, e.g. on the changeover mechanism, pressure cylinder and in the frame, and have to perform axial and rotary movements.

With just one push button on each handle, the animax can be simultaneously engaged in width and height almost steplessly according to the respective body dimensions when setting up the device. The switching mechanism has two cylindrical iglidur ® bearings one behind the other in two hollow shafts. In turn, the inner hollow shaft is mounted in each bearing without the risk of edges. To facilitate the turning of the link, the tolerance of the inner guide sleeve was set further into the negative. This makes it necessary to absorb the torque generated by the lever at another point. This is done in the plain bearings of the component "Bridge". On the test rig, bearings with a steel jacket and PTFE coating did not withstand the load trade show. By testing various bearing bushes, the igus® Z-bearing proved to be the best solution. The frame is a portal frame in which a total of four tubes are telescoped. An extruded aluminium profile was produced for this purpose, into each of which a plain bearing is pressed. Thanks to the thin-walled igus® foil plain bearings, it was possible to design the profiles themselves with thinner walls. This saved weight and costs. The same foil bushings are used in the pull-out mechanism of the lever. The entire lever mechanism was designed with igus® plastic plain bearings at all pivot points. This enables precise, solid and yet effective operation. Each device uses 22 cylindrical and 9 flanged bushes, as well as a thrust washer. During the endurance test by the BerlinCert testing and certification centre, the device withstood the load without any problems right from the start.