Refrigerant motor

Claim 1

A motor adapted to convert energy from a stream of gaseous refrigerant flowing through a closed circuit having a high temperature source and a low temperature sink which comprises: a casing defining a chamber; a flexible diaphragm dividing the chamber into a driving chamber and an equalizing chamber; a rod connected to reciprocate with the diaphragm; a port for allowing gaseous refrigerant to flow into and out of the driving chamber; a spool valve having a valve casing defining a valve chamber and having: (a) an inlet valve port for the receipt of gaseous refrigerant from the refrigeration circuit; (b) a common valve port for the discharge and receipt of gaseous refrigerant from the entry port of the driving chamber; and (c) An exit port for the discharge of gaseous refrigerant to the refrigeration circuit; a spool located within the valve chamber having a spool middle portion which communicates inlet valve port with the common port when the spool is in a first position and the common port with the exit port when the spool is in a second position; a valve actuator connected to the diaphragm, said valve actuator having an end which engages the end of the spool to move the spool from the second position to the first position and has a spool portion connected to a pilot line for allowing gaseous refrigerant to enter a pilot chamber portion of the valve chamber for displacing the spool from the first position to the second position, said spool portion communicating the driving chamber with the pilot chamber through a pilot line; and a pump connected to the rod for circulating refrigerant within the closed circuit.