The refrigerator compressor is essentially a compressor that compresses not air, but a medium that can be transformed from gas to liquid by compression. After减压, this liquid reverts to gas, absorbing heat during the phase change from liquid to gas, thereby cooling. Such gas mediums include ammonia, low molecular weight hydrocarbons, chlorofluorocarbons, and more. The task of this type of compressor is to cool, serving as the heart of large cold storage facilities, air conditioners, refrigerators, and so on, also known as refrigerators.

The lubricating oil used in refrigeration machines is known as refrigeration oil. Its performance requirements include: appropriate viscosity and good viscosity-temperature characteristics, good thermal and chemical stability, good low-temperature performance, excellent wear resistance, low water content, and good insulating properties.