The U-02 unit contains two screw compressors and one screw expander coupled to a common drive shaft through the gearbox and intent to create conditioned air without the use of refrigerants. This unit is very compact and most suitable for cooling of small aircrafts during ground support mode.
The compression and expansion of air is “oil free” in the respect that lubrication oil is prevented from entering the process air in the machine. The design features oil lubricated rolling element bearings and gear wheels as well as dry type labyrinth shaft seals. A controlled leakage of process air into the oil circuit and out to atmosphere is designed in the machine in order to prevent oil from entering the process air.
The U-02 unit is successfully used in ground support for aviation since many years on several markets after it was developed and patented by SRM.