A screw compressor includes a screw rotor including a rotor shaft, a radial bearing, a thrust plate, a balance mechanism, which is a slide bearing, a lubrication oil supply flow passage for supplying a lubrication oil, and a working fluid supply flow passage for supplying a working fluid for pressing the balance mechanism toward the thrust plate so that a reverse thrust load acts on the thrust plate.

A screw compressor utilizing radial and axial or thrust bearings to maintain the position of the rotors radially and axially and utilizing a damping fluid to dampen rotor vibrations. The damping fluid may conveniently be provided in the form of lubricant that is already used in the compressor to seal the clearances between the rotors and between the rotors and the cylinder during compression. The damping fluid is included in a squeeze film damper, arranged in a parallel arrangement with the radial or thrust bearings, which provides viscous damping to the rotor. The introduction of additional viscous damping such as may be provided by squeeze film dampers may result in significant reduction of compressor vibration regardless of the source of vibration.

A screw compressor utilizing radial and axial or thrust bearings to maintain the position of the rotors radially and axially and utilizing a damping fluid to dampen rotor vibrations. The damping fluid may conveniently be provided in the form of lubricant that is already used in the compressor to seal the clearances between the rotors and between the rotors and the cylinder during compression. The damping fluid is included in a squeeze film damper, arranged in a parallel arrangement with the radial or thrust bearings, which provides viscous damping to the rotor. The introduction of additional viscous damping such as may be provided by squeeze film dampers may result in significant reduction of compressor vibration regardless of the source of vibration.

A rotary compressor or expander apparatus embodies a scaling solution that is based on the physical configuration of the leakage path and various of its features to substantially inhibit flow of fluid through the leakage path, with minimal leakage.

A rotary compressor or expander apparatus embodies a scaling solution that is based on the physical configuration of the leakage path and various of its features to substantially inhibit flow of fluid through the leakage path, with minimal leakage.