A high efficient linear motor for compressor applications

This paper presents a free piston compressor with a new type of linear reciprocating drive which is designed to increase efficiency and performance. The integrated mechatronic system comprises a free piston compressor that is directly powered by a linear permanent magnet synchronous motor. Two major challenges of linear free piston compressors are to reach a high power density which can be expressed in terms of volumetric flow per compressor size and a high efficiency of the linear drive during a compression cycle. The presented long stroke linear oscillating actuator features an integrated magnetic spring that allows to recycle the kinetic energy of the moving mass without the need of voluminous mechanical springs. This allows a highly integrated and compact design solution that features high efficiency even under fractional stroke operation.