Electromagnetically actuated reciprocating compressor driver

Abstract

A compressor is disclosed having an electromagnetic actuator for driving the piston in the compression cylinder. The actuator includes an electromagnetic element having a core and a coil. The core has an electromagnet surface and a channel extending through the core. The coil is disposed in the channel. An axially reciprocating armature element is interconnected with the piston. The armature element defines an axial stroke having a stroke midpoint and a stroke peak. The armature element also has an armature surface dimensioned to align with and correspond to the electromagnet surface at the stroke peak. The actuator also includes a primary spring disposed on one end of the armature element for biasing the armature from movement in an axial direction. A secondary spring is disposed on the opposing end of the armature element and biases the armature from movement in an opposite axial direction. The armature is biased by the springs to resonate at a pre-determined frequency. Applying current to the coil in the electromagnetic element when the armature surface passes through the stroke midpoint allows the armature to overcome losses due to friction and compression forces, and causes the armature to continue resonating at the predetermined frequency. Two actuators may be placed back-to-back to create a dual piston compressor.