Scroll expander

Patent metadata

Field	Value
Publication number	US-10301940-B2
Application number	US-201515118412-A
Country	US
Kind code	B2
Filing date	Feb 9, 2015
Priority date	Feb 12, 2014
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

Scroll expander including a bypass passage and a bypass valve configured to open and close the bypass passage without significantly increasing the length in the shaft direction of the scroll expander. Scroll expander 23 includes suction port 513 which allows a high-pressure flow of a working fluid to enter and guides the entering flow of the working fluid into an expansion chamber. Discharge port 523 allows the working fluid expanded to a lower pressure in the expansion chamber to flow out. Bypass passage 27 communicates suction port 513 with the discharge port 523 while bypassing the expansion chamber. Bypass valve 28 is configured to open and close bypass passage 27. Suction port 513, bypass passage 27 and a bypass valve attaching portion 514 for attaching the bypass valve 28 are formed in a base plate of the fixed scroll 51.

First claim

The invention claimed is:

1. A scroll expander including a fixed scroll and a movable scroll which define an expansion chamber therebetween, the movable scroll being configured to be driven by expansion of working fluid in the expansion chamber, comprising:
a suction port which allows a high-pressure flow of the working fluid to enter, and which guides the entering flow of the working fluid into the expansion chamber;
a discharge port which allows the working fluid expanded to a lower pressure in the expansion chamber to flow out;
a bypass passage through which the suction port communicates with the discharge port while bypassing the expansion chamber; and
a bypass valve configured to open and close the bypass passage,

wherein:
the suction port, the bypass passage and a bypass valve attaching portion for attaching the bypass valve are formed in a base plate of the fixed scroll,
both of the suction port and the bypass passage extend along a scroll non-forming surface, which is opposite to a scroll forming surface in which a scroll wall is formed, of the base plate of the fixed scroll, and then curves to pass through the base plate of the fixed scroll till reaching the scroll forming surface, the suction port and the bypass passage reaching different positions from each other in the scroll forming surface, and
the bypass valve attaching portion is formed as a hole for inserting the bypass valve so as to extend along the scroll non-forming surface of the base plate of the fixed scroll in communication with the bypass passage.

2. The scroll expander according to claim 1 , wherein
in the scroll non-forming surface of the base plate of the fixed scroll, the bypass passage crosses the suction port, and opens at one end to an outside so as to have an outer opening end, and
the outer opening end of the bypass passage is closed by a condition detection sensor that is configured to detect a condition of the working fluid in the flow entering the suction port.

3. The scroll expander according to claim 2 , wherein
the suction port opens to the outside at one end located near a periphery of the scroll non-forming surface of the base plate of the fixed scroll, and opens at the other end located at a center of the scroll forming surface of the base plate of the fixed scroll,
the bypass passage opens to the outside at one end located near a center of the scroll non-forming surface of the base plate of the fixed scroll, and opens at the other end located external to the scroll wall in the scroll forming surface of the base plate of the fixed scroll, and
the bypass valve attaching portion opens near the periphery of the scroll non-forming surface of the base plate of the fixed scroll.

4. The scroll expander according to claim 3 , wherein the suction port is formed in parallel to the bypass valve attaching portion in the scroll non-forming surface of the base plate of the fixed scroll.

5. The scroll expander according to claim 3 , wherein, when the scroll expander is viewed in an axis direction of a rotating shaft, an outer opening end of the suction port, an opening end of the bypass valve attaching portion, and an outer opening end of the discharge port are all disposed on one side of the scroll expander.

6. The scroll expander according to claim 1 , wherein, at least either of at least one rib and at least one thick portion is formed in an area including none of the suction port, the bypass passage and the bypass valve attaching portion on the scroll non-forming surface of the base plate of the fixed scroll.

7. A scroll expander including a fixed scroll and a movable scroll which define an expansion chamber therebetween, the movable scroll being configured to be driven by expansion of working fluid in the expansion chamber, comprising:
a suction port which allows a high-pressure flow of the working fluid to enter, and which guides the entering flow of the working fluid into the expansion chamber;
a discharge port which allows the working fluid expanded to a lower pressure in the expansion chamber to flow out;
a bypass passage through which the suction port communicates with the discharge port while bypassing the expansion chamber; and
a bypass valve configured to open and close the bypass passage,
wherein:
the suction port, the bypass passage and a bypass valve attaching portion for attaching the bypass valve are formed in a base plate of the fixed scroll,
both of the suction port and the bypass passage extend along a scroll non-forming surface, which is opposite to a scroll forming surface in which a scroll wall is formed, of the base plate of the fixed scroll, and then curves to pass through the base plate of the fixed scroll till reaching the scroll forming surface,
the bypass valve attaching portion is formed as a hole for inserting the bypass valve so as to extend along the scroll non-forming surface of the base plate of the fixed scroll in communication with the bypass passage, and
at least either of at least one rib and at least one thick portion is formed in an area including none of the suction port, the bypass passage and the bypass valve attaching portion on the scroll non-forming surface of the base plate of the fixed scroll.

Assignees

• Sanden Holdings Corp

Inventors

• Tanaka Yuuta

Classifications

• F01C21/10

  Outer members for co-operation with rotary pistons; Casings (casings for rotary engines or machines in general F16M) · CPC title

• F01C1/02

  of arcuate-engagement type, i.e. with circular translatory movement of co-operating members, each member having the same number of teeth or tooth-equivalents · CPC title

• F01C1/0215

  where only one member is moving · CPC title

• F01C20/26 Primary

  using bypass channels · CPC title

• F01C20/28

  Safety arrangements; Monitoring · CPC title