Compressor for a cooling device and a refrigeration machine

A device comprising:

• a compressor chamber;
• a membrane that divides the compressor chamber into a first volume and a second volume, wherein the first volume contains a working gas and the second volume contains a working liquid, wherein the membrane is constructed as a balloon that surrounds the first volume, wherein the membrane is elastic, gas-tight and liquid-tight, and wherein the working liquid is a hydraulic oil that surrounds the outside of the balloon;
• a first working gas connection that is coupled to the first volume;
• a working liquid connection that is coupled to the second volume;
• a pump device that periodically pumps the working liquid through the working liquid connection and into the second volume and as a result periodically compresses the working gas in the first volume;
• a cooling device that receives compressed working gas via the first working gas connection from the first volume;
• a working gas reservoir containing the working gas;
• a differential pressure regulator adapted to allow the working gas to flow from the working gas reservoir into the first volume via the differential pressure regulator and the first working gas connection when the working gas in the first volume has a pressure lower than that of the working gas in the working gas reservoir;
• and
• an over pressure valve adapted to allow the working gas to flow from the first volume into the working gas reservoir via the first working gas connection and then the over pressure valve when the pressure of the working gas in the first volume becomes too high so as to risk damaging the device, wherein the working gas is supplied to the cooling device via the first working gas connection without passing through either the over pressure valve or the working gas reservoir.