Scroll expander

Abstract

A scroll expander includes a housing, a main port, a high-pressure chamber, an operation chamber, a low-pressure chamber, a subport, a valve portion, an actuator, and a drive shaft. The high-pressure and low-pressure chambers are separated by a partition wall. The main port draws working fluid in the high-pressure chamber into the operation chamber. The subport introduces the working fluid from the high-pressure chamber to the operation chamber so that the volume of the working fluid in the operation chamber is variable. The valve portion selectively opens and closes the subport. The actuator is arranged in the low-pressure chamber. The drive shaft extends through the partition wall and connects the actuator and the valve portion with each other. When the drive shaft is actuated by the actuator, the subport is selectively opened and closed by the valve portion.

1 . A scroll expander comprising:
 a housing having an inner circumferential surface;   a fixed scroll, which is accommodated in the housing and fixed to the inner circumferential surface of the housing;   a moveable scroll, which is accommodated in the housing and arranged to face the fixed scroll;   a high-pressure chamber formed in the housing, to which high-pressure working fluid is supplied;   an operation chamber defined by the fixed scroll and the moveable scroll, in which working fluid introduced from the high-pressure chamber is expanded;   a low-pressure chamber formed in the housing, to which working fluid that has been expanded and decompressed in the operation chamber is discharged;   a partition wall that separates a space in the housing into the high-pressure chamber and the low-pressure chamber;   a main port, which draws the working fluid in the high-pressure chamber into the operation chamber;   a subport, which introduces the working fluid from the high-pressure chamber to the operation chamber so that a volume of the working fluid in the operation chamber is variable;   a valve portion, which selectively opens and closes the subport;   an actuator, which applies drive force to move the valve portion, is arranged in the low-pressure chamber; and   a drive shaft that extends through the partition wall and connects the actuator and the valve portion with each other, wherein   when the drive shaft is actuated by the actuator, the valve portion is moved by the actuation of the drive shaft so that the subport is selectively opened and closed.   
     
     
         2 . The scroll expander according to  claim 1 , wherein the actuator includes an electric motor. 
     
     
         3 . The scroll expander according to  claim 2 , wherein
 the electric motor includes a motor portion and a case that accommodates the motor portion therein,   a part of the case extends through the housing to be exposed to an outside of the housing,   the case has a through hole in the portion exposed to the outside of the housing, and   the inside of the case and the outside of the housing are connected with each other via the through hole.   
     
     
         4 . The scroll expander according to  claim 2 , wherein
 the electric motor includes a motor portion and a case that accommodates the motor portion therein,   the drive shaft extends through the case to be connected to the motor portion, and   the inside of the case and the low-pressure chamber are connected with each other via an interface between the case and the drive shaft.   
     
     
         5 . The scroll expander according to  claim 2 , wherein
 the electric motor includes a motor portion and a case that accommodates the motor portion therein,   the drive shaft extends through the case to be connected to the motor portion,   a sealing member is arranged between the case and the partition wall, and   the inside of the case and the high-pressure chamber are connected with each other via an interface between the partition wall and the drive shaft and an interface between the case and the drive shaft.