摘要 |
A rotor is journalled in a housing having gas inlet ports and outlet ports for compressed gas, the gas being compressed in working chambers formed between the rotor, an inner surface of the housing and vanes which periodically move inward and outward in slots in the rotor during its rotation and while sliding against said inner surface of the housing. Oil or other liquid is injected into the working chambers through grooves in at least one internal wall of the housing, the grooves being positioned to communicate with the working chambers through small recesses, located in edge portions of the rotor, during at least parts of the periods starting when a vane immediately trailing one of said recesses has just passed a said inlet port, thus blocking the connection between said last inlet port and the corresponding working chamber immediately preceding said vane, and ending when the pressure in said corresponding working chamber equals the liquid injection pressure. |