SCROLL EXPANDER

摘要

Disclosed is a scroll expander in which an inlet and an outlet of an asymmetric scroll are disposed close to an intake port and a discharge port of the expander so that it is possible to minimize loss of a fluid path and a temperature increase and to enhance the volume and heat-insulation efficiency of the expander, and an expansion chamber and a back-pressure chamber of the scroll communicate with each other so that it is possible to effectively lubricate various frictional parts, including a rotation preventing mechanism and a bearing in the interior of the back-pressure chamber, thereby reducing frictional loss. The above-described scroll expander comprises: a casing (10) that has an intake port (12) and a discharge port (14) for intake and discharge of working fluid; an intake chamber (80) that communicates with the intake port (12) in the casing (10); a discharge chamber (84) that communicates with the discharge port (14) in the casing (10); a fixed scroll (20) and a swivel scroll (30) that form an expansion chamber (82) between the intake chamber (80) and the discharge chamber (84); a rotating shaft (40) that supports the swivel scroll (30) such that the swivel scroll (30) moves around the fixed scroll (20) while being offset from the fixed scroll (20); a back-pressure chamber (86) disposed on the rear of the swivel scroll (30) to adjust a contact clearance between the fixed scroll (20) and the swivel scroll (30); and a bypass passage (26) that communicates the expansion chamber (82) with the back-pressure chamber (86) to supply part of the working fluid in the expansion chamber (82) to the back-pressure chamber (86).