A driving device of a circuit breaker closing/opening actuating mechanism, comprising:
- a heater,
- a metal shell,
- an expansive matter positioned inside an inner sealed chamber of said metal shell, and
- a converter of volume expansion-displacement expansion, wherein said converter of volume expansion-displacement expansion comprises an ejector rod piston, wherein said metal shell has an ejector rod through hole provided on a top surface thereof;
- said ejector rod piston is movably mounted inside said ejector rod through hole;
- said ejector rod piston is sealedly connected with said metal shell;
- a portion of said ejector rod piston positioned inside said inner sealed chamber of said metal shell is connected with said expansive matter directly or indirectly;
- a mixture of a fluid medium and said expansive matter is positioned inside said inner sealed chamber of said metal shell;
- said portion of said ejector rod piston positioned inside said inner sealed chamber of said metal shell is positioned in said fluid medium;
- and a separating membrane is positioned in said inner sealed chamber of said metal shell, and provided between said fluid medium and said expansive matter;
- wherein said separating membrane is metallic or made of high polymer material, for receiving an expansion force produced by said expansive matter to motive said ejector rod piston;
- and said fluid medium is for converting said volume expansion of phase transforming of said expansive matter into an expansion force and displacement transmitted into said ejector rod piston, in such a manner that, when said heater is powered on, said expansive matter expands to produce a volume-displacement change to motivate said force transmitting mechanism, for opening/closing a circuit breaker;
- wherein said volume expansion of said expansive matter in said expansion body is produced by phase transforming of solid phase-liquid phase or liquid phase-gas phase of said expansive matter;
- wherein a sealing element is mounted between said ejector rod piston and said metal shell, said sealing element is selected from the group consisting of a sealing O ring, a sealing pad, and an annular sealing sleeve;
- wherein said heater is positioned in said expansive matter inside said metal shell, or outside said metal shell contacting with said expansive matter;
- and
- wherein said expansive matter is paraffin;
- and said heater adopts a positive temperature coefficient (PTC) thermistor for avoiding overheating, or an electric heating element.