Fluid Machinery

Abstract

A fluid machinery including: an expander that generates power by expansion of refrigerant; and a piston pump that pumps the refrigerant, and capable of reducing a decrease in lubrication performance of a mechanical sliding section in a crank chamber of the piston pump. A fluid machinery 29A includes an expander unit (scroll expander) 60A that generates power by expansion of refrigerant, and a pump unit (piston pump) 50A that pumps the refrigerant. A rotating shaft 28 of the fluid machinery 29A functions as an output shaft of the expander unit 60A and a drive shaft of the pump unit 50A. The rotating shaft 28 has a crank section 28a housed in the crank chamber 72A. A refrigerant outlet chamber 78A, through which the expanded refrigerant is discharged from the expander unit 60A, communicates with the crank chamber 72A via a bearing 71b, a housing space of a driven crank mechanism 80, and an anti-rotation member 77.

Description

TECHNICAL FIELD[0001]The present invention relates to a fluid machinery used by being incorporated into a Rankine cycle or the like, in particular, relates to a fluid machinery that is provided with an expander that generates power by expansion of a refrigerant, and a piston pump that pumps the refrigerant.BACKGROUND ART[0002]As a fluid machinery incorporated into a Rankine cycle, a pump-integrated expander in which an expander that generates power by expansion of a refrigerant is integrally connected to a pump that pumps the refrigerant has been known (for example, see Patent Document 1). Inventors have considered adopting a piston pump, with high volumetric efficiency from a low rotational speed area to a high rotational speed area, as a pump of the fluid machinery of this type. In this case, a liquid-phase refrigerant drawn into the piston pump might flow into a crank chamber, and thus, there may be a concern over degradation of a lubrication state of each sliding section in the ...

AI Technical Summary

Benefits of technology

[0009]According to the fluid machinery, since the interior of the crank chamber is set to a state in which the liquid-phase refrigerant is easily gasified, by allowing the refrigerant outlet section, through which the refrigerant after expansion is discharged from the expander, to communicate with the crank chamber of the piston pump, it is possible to reduce an amount of liquid-phase refrigerant that flows into the crank chamber and / or is stored in the crank chamber. Furthermore, there is little fear of gasification of the drawn refrigerant of the pump as in the above-described related arts. This can reduce the risk of a decrease in volumetric efficiency of the piston pump, while reducing a decrease in lubrication performance of the mechanical sliding section of the piston pump.

Problems solved by technology

In this case, a liquid-phase refrigerant drawn into the piston pump might flow into a crank chamber, and thus, there may be a concern over degradation of a lubrication state of each sliding section in the crank chamber.

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