For a piston rod in a refrigeration compressor, it was necessary to absorb both the vibrations and lateral misalignment of the plunger. In addition, the guide system had to provide a long service life and be chemically resistant to the refrigerant.
The solution consisted of an aluminum flange into which spring-elastic U-cup seals were press-fitted. Their tolerance zones were machined with high precision. This resulted in a preloaded yet vibration-damping and low-friction plain bearing support for the piston rod.
The image also shows an earlier stage of the development featuring a simpler design made from PET. However, this solution was ultimately rejected due to insufficient chemical resistance.
