Variable Gap-Reluctance Linear Motor With Application to Linear Resonance Compressors

Abstract

Variable gap-reluctance linear motors operate on the principle of electromagnetic attraction across an air gap between a moving armature and a stator and coil, which minimizes reluctance or stored magnetic energy. The direction of motion, force and magnetic field are aligned and are perpendicular to the air gap. When the air gap and corresponding stroke are moderate, large amounts of force and power can be delivered from a compact design. Several sizes of a new variable gap-reluctance linear motor design have been developed, characterized and applied. Practical application is demonstrated for linear resonance diaphragm refrigerant and gas compressors. A leaf spring suspension is used to dynamically match the motor to the resonance compressor load. Analysis and experimental results are combined to develop and characterize both the basic motor and integrated compressor designs.