| 摘要 |
A device for controlling the volumetric capacity of a screw compressor having two rotors, which are in meshing engagement with each other, in a compression chamber enclosed in a housing, in which there is also arranged a bore in parallel with the rotors, the bore being connected to the compression chamber through a number of channels distributed axially in the bore, a plunger being arranged to be movably guided in the bore as volume control is effected. Depending on the position of the plunger in the bore, the number of the channels covered thereby varies. The plunger is hollow and has an opening at one end through which a rod fixed in the bore passes, the rod carrying a piston sealingly engaging the inside surface of the plunger. At its other end, the plunger is closed by an end wall. The position of the plunger in the bore is adjusted by the supply of a control medium, such as oil, which influences both sides of the end wall. Any volatile refrigerant, such as R22 or R12, dissolved in the control medium will not affect the capacity set by the device. |
