WO2016121418A1

WO2016121418A1 - Stirling refrigerator

Info

Publication number: WO2016121418A1
Application number: PCT/JP2016/050127
Authority: WO
Inventors: 中野　恭介; 善勝平塚; 健太湯本
Original assignee: 住友重機械工業株式会社
Priority date: 2015-01-29
Filing date: 2016-01-05
Publication date: 2016-08-04

Abstract

An expander (13) is provided with: a displacer (22) that extends in the axial direction; a cold accumulator (38) that is installed around the displacer (22) so as to guide reciprocation of the displacer (22) in the axial direction; and an expander case (20). The expander case (20) has a connecting port (56) that is formed at a first circumferential position and that connects a compression space (36) to a connecting pipe (12), and is provided with a case section that extends from the connecting port (56) in the circumferential direction and that surrounds the compression space (36). A first working-gas area (60) of the compression space (36) is formed, at the first circumferential position, between the connecting port (56) and the displacer (22). A second working-gas area (62) of the compression space (36) is formed, at a second circumferential position that is different from the first circumferential position, between the case section and the displacer (22). A second radial width of the second working-gas area (62) is smaller than a first radial width of the first working-gas area (60).

Description

Stirling refrigerator

The present invention relates to a Stirling refrigerator.

As a kind of Stirling refrigerator, a split type Stirling refrigerator in which the movable part of the compressor and the movable part of the expander are not mechanically connected is known. The split Stirling refrigerator includes a compressor, an expander, and a connecting pipe that connects the compressor to the expander. The connecting pipe is connected to the side of the expander and communicates with the working gas receiving chamber of the expander. The expander is provided with a regenerator. The working gas flows from the outlet of the connecting pipe into the regenerator through the working gas receiving chamber.

JP 2000-121187 A

When working gas flows into the expander from the compressor, the working gas is ejected from the outlet of the connecting pipe into the working gas receiving chamber. The ejected gas is directed toward a certain region of the gas receiving chamber, for example, a region opposite to the connecting pipe outlet by virtue of the momentum. Therefore, the gas flow rate flowing into the regenerator from that region can be larger than the gas flow rate flowing into the regenerator from another region, for example, the region on the connection pipe side. In this way, drift is generated in the regenerator. That is, a location where the gas flow rate is relatively high and a location where the gas flow rate is relatively small are generated in the regenerator, and as a result, a temperature difference may occur between these regions. Such a non-uniform regenerator temperature distribution causes a decrease in performance of the regenerator. The drift can be prominent when the operating frequency of the refrigerator is high or when the refrigerator is large.

One exemplary purpose of one aspect of the present invention is to mitigate the drift of working gas that can occur in a regenerator of a Stirling refrigerator.

According to an aspect of the present invention, there is provided a Stirling refrigerator that includes an expander, a compressor, and a connecting pipe that connects the compressor to the expander. The expander is a displacer extending in the axial direction, the displacer facing the working gas expansion space on one end side in the axial direction and facing the working gas compression space on the other end side in the axial direction, and the displacer in the axial direction. A regenerator that is disposed around the displacer so as to guide the reciprocating movement of the displacer and forms a working gas flow path between the working gas compression space and the working gas expansion space, and contains the displacer and the regenerator. An expander container that has a connection port that is formed at a first circumferential position and connects the working gas compression space to the connection pipe, and extends in the circumferential direction from the connection port to define the working gas compression space. An expander container including an enclosing container portion. A first working gas region of the working gas compression space is formed between the connection port and the displacer at the first circumferential position, and the first working gas region is formed at the connection port at the first circumferential position. And the displacer has a first radial width. A second working gas region of the working gas compression space is formed between the container portion and the displacer at a second circumferential position different from the first circumferential position, and the second working gas region is the second working gas region. A second radial width is provided between the container portion and the displacer at a circumferential position. The second radial width is smaller than the first radial width.

According to an aspect of the present invention, there is provided a Stirling refrigerator that includes an expander, a compressor, and a connecting pipe that connects the compressor to the expander. The expander is a regenerator extending in the direction of the central axis, and the working gas expansion space located on one end side of the regenerator in the direction of the central axis and the regenerator in the direction of the central axis. A regenerator that forms a working gas flow path between the working gas compression space located on the end side, and an expander container that accommodates the regenerator, the container having a container portion surrounding the working gas compression space A container. The connection pipe is connected to the compressor at one end and has a main pipe having a branching part at the other end, a first branch pipe branched from the main pipe at the branching part, and a first branch pipe branched from the main pipe at the branching part. A two-branch pipe. The container portion is formed on one side with respect to the central axis and connected to the first branch pipe, and is formed on the other side with respect to the central axis and connected to the second branch pipe. A second connection port.

According to an aspect of the present invention, there is provided a Stirling refrigerator including an expander, at least one compressor, and at least one connection pipe connecting the at least one compressor to the expander. The expander is a regenerator extending in the direction of the central axis, and the working gas compression space located on one end side of the regenerator in the direction of the central axis and the other of the regenerator in the direction of the central axis. A regenerator that forms a working gas flow path between a working gas expansion space located on the end side, and an expander container that houses the regenerator, the container having a container portion surrounding the working gas compression space A container. The container portion is formed on one side with respect to the central axis and connected to the connecting pipe, and the second connection is formed on the other side with respect to the central axis and connected to the connecting pipe. And a mouth.

It should be noted that any combination of the above-described constituent elements and the constituent elements and expressions of the present invention that are mutually replaced between methods, apparatuses, systems, etc. are also effective as an aspect of the present invention.

According to the present invention, it is possible to reduce the drift of working gas that may occur in the regenerator of the Stirling refrigerator.

It is a figure showing roughly the Stirling refrigerator concerning a 1st embodiment of the present invention. It is sectional drawing which shows roughly the expander of the Stirling refrigerator which concerns on 1st Embodiment of this invention. It is sectional drawing which shows schematically the block and displacer rod which concern on 1st Embodiment of this invention. It is sectional drawing which shows schematically the expander of a certain Stirling refrigerator. It is sectional drawing which shows schematically the expander of the Stirling refrigerator which concerns on other embodiment of this invention. It is sectional drawing which shows schematically the displacer rod which concerns on other embodiment of this invention. It is a figure which shows schematically the Stirling refrigerator which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows schematically the expander of the Stirling refrigerator which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows schematically the expander of a certain Stirling refrigerator. It is sectional drawing which shows schematically the expander of the Stirling refrigerator which concerns on other embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. Moreover, the structure described below is an illustration and does not limit the scope of the present invention at all.

(First embodiment)
FIG. 1 is a diagram schematically showing a Stirling refrigerator 10 according to the first embodiment of the present invention. The Stirling refrigerator 10 includes a compressor 11, a connecting pipe 12, and an expander 13. The Stirling refrigerator 10 is a split type Stirling refrigerator.

The compressor 11 includes a compressor case 14. The compressor case 14 is a pressure vessel configured to hold a high-pressure working gas in an airtight manner. The working gas is, for example, helium gas. The compressor 11 includes a compressor unit that is accommodated in the compressor case 14. The compressor unit includes a compressor piston and a compressor cylinder, one of which is a movable member 15 configured to reciprocate in the compressor case 14 and the other is fixed to the compressor case 14. It is a stationary member. The compressor unit includes a drive source for moving the movable member 15 relative to the compressor case 14 in a direction along the central axis of the movable member 15. The compressor 11 includes a support portion 16 that supports the movable member 15 on the compressor case 14 so that the movable member 15 can reciprocate. The movable member 15 vibrates with respect to the compressor case 14 and the stationary member with a certain amplitude and frequency. As a result, the volume and pressure of the working gas in the compressor 11 also vibrate with a specific amplitude and frequency.

A working gas chamber is formed between the compressor piston and the compressor cylinder. This working gas chamber is connected to one end of the connection pipe 12 through a communication passage formed in the stationary member and the compressor case 14 described above. The other end of the connection pipe 12 is connected to the working gas receiving chamber of the expander 13. Thus, the working gas chamber of the compressor 11 is connected to the working gas receiving chamber of the expander 13 by the connecting pipe 12.

The expander 13 includes an expander container 20, a displacer 22, and at least one support portion 40, as will be described later with reference to FIG.

FIG. 2 is a diagram schematically showing the expander 13 according to the first embodiment of the present invention. FIG. 2 shows an outline of the internal structure of the expander 13.

The expander container 20 is a pressure container configured to hold a high-pressure working gas in an airtight manner. This pressure vessel may be composed of a plurality of vessel parts connected to each other so as to keep the inside airtight. The displacer 22 is a movable member configured to reciprocate in the expander container 20. The support part 40 supports the displacer 22 on the expander container 20 so that the displacer 22 can reciprocate.

The expander container 20 includes a first compartment 24 and a second compartment 26. The first compartment 24 includes a working gas expansion space 28 and a compression space 36 formed between the expander vessel 20 and the displacer 22. A portion of the expander container 20 adjacent to the expansion space 28 is provided with a cooling stage 29 for cooling the object. The cooling stage 29 is also called a cold head. The second section 26 is configured to support the displacer 22 on the expander container 20 via the elastic member 30.

The second section 26 is adjacent to the first section 24 in the reciprocating direction of the displacer 22 (indicated by an arrow C in the figure). A seal portion 25 is provided between the second compartment 26 and the first compartment 24, whereby the second compartment 26 is partitioned from the first compartment 24. Therefore, the pressure fluctuation of the working gas in the first section 24 is not transmitted to the second section 26 or does not significantly affect the pressure of the working gas in the second section 26. Note that the second compartment 26 is filled with the same type of gas as the working gas so as to have a pressure equivalent to the average pressure of the working gas flowing through the connecting pipe 12.

The displacer 22 includes a displacer head 32 accommodated in the first section 24 and a displacer rod 34. The displacer rod 34 is a shaft portion thinner than the displacer head 32. The displacer 22 has a central axis (indicated by the alternate long and short dash line A in the figure) parallel to the reciprocating direction of the displacer, and the displacer head 32 and the displacer rod 34 are provided coaxially with the central axis of the displacer 22. The displacer head 32 has a cavity inside and is filled with the same kind of gas as the working gas.

The displacer rod 34 extends from the displacer head 32 through the seal portion 25 to the second section 26. The displacer rod 34 is supported by the expander vessel 20 in the second compartment 26 to allow the displacer 22 to reciprocate. The above-described seal portion 25 may be, for example, a rod seal formed between the displacer rod 34 and the expander container 20. Similar to the displacer head 32, the displacer rod 34 also has a cavity inside. The cavity of the displacer rod 34 is connected to the cavity of the displacer head 32. The distal end of the displacer rod 34 may be opened, and the internal cavity of the displacer 22 may be communicated with the second compartment 26.

The first section 24 forms a cylinder portion that surrounds the displacer head 32. An expansion space 28 is formed between the bottom surface of the cylinder portion (that is, the inner surface of the cooling stage 29) and the distal end surface 32a of the displacer head 32. The expansion space 28 is formed on the opposite side of the joint between the displacer head 32 and the displacer rod 34 in the reciprocating direction of the displacer 22. A compressed gas space 36 for the working gas in the expander 13 is formed between the joint portion and the seal portion 25. Therefore, the displacer head 32 faces the expansion space 28 on one end side in the axial direction and faces the compression space 36 on the other end side in the axial direction. The compression space 36 is a working gas receiving chamber of the expander 13 connected to the compressor 11 through the connection pipe 12.

A regenerator 38 is provided in the cylinder portion of the expander container 20 adjacent to the radially outer side of the displacer head 32. Here, the radial direction refers to a direction perpendicular to the direction of the central axis. Thus, the regenerator 38 is accommodated in the expander container 20. The regenerator 38 extends in the axial direction coaxially with the displacer 22 and is formed in an annular shape or a donut shape. More specifically, the regenerator 38 is provided on the side surface of the cylinder portion of the expander container 20 so as to be located in a cylindrical region having the longitudinal axis of the displacer 22 as a central axis in the outer peripheral portion of the displacer head 32. . The regenerator 38 includes, for example, a wire mesh laminated structure as a regenerator material. The working gas can be circulated between the expansion space 28 and the compression space 36 through a regenerator 38. The expansion space 28 is located on one end side of the regenerator 38 in the direction of the central axis, and the compression space 36 is located on the other end side of the regenerator 38 in the direction of the central axis.

A radiator 37 is provided adjacent to the regenerator 38 between the regenerator 38 and the compression space 36 in the axial direction. The radiator 37 is, for example, a water-cooled heat exchanger. Similarly to the regenerator 38, the radiator 37 is also formed in an annular shape or a donut shape. The radiator 37 forms a cylinder part together with the regenerator 38.

The heat radiator 37 cools the working gas supplied from the compressor 11 and realizes heat exchange for releasing the heat to the outside of the expander 13. Since the working gas supplied from the compressor 11 to the compression space 36 generally has a temperature higher than room temperature, the radiator 37 cools the high-temperature gas to about room temperature.

The radiator 37 is disposed around the displacer head 32. The side surface of the displacer head 32 is slidable with the inner wall portion of the radiator 37, whereby the radiator 37 can guide the reciprocating movement of the displacer head 32 in the axial direction. A seal portion that prevents the working gas from flowing through the compression space 36 and the expansion space 28 may be formed between the side surface of the displacer head 32 and the inner wall portion of the radiator 37.

Further, a low-temperature heat exchanger 39 is attached adjacent to the regenerator 38 between the regenerator 38 and the cooling stage 29 in the axial direction. The low temperature heat exchanger 39 is disposed around the displacer tip. A working gas flow path that connects the compression space 36 and the expansion space 28 is formed by a radiator 37, a regenerator 38, and a low-temperature heat exchanger 39. A minute clearance may be formed between the regenerator 38 and the displacer head 32 in the radial direction. Similarly, a minute clearance may be formed between the low-temperature heat exchanger 39 and the displacer head 32 in the radial direction.

The expander 13 supports the displacer 22 on the expander container 20 so that the displacer 22 can reciprocate at a plurality of different positions in the reciprocating direction of the displacer 22. For this purpose, the expander 13 includes two support portions 40. These two support portions 40 are provided in the second section 26. Further, as described above, the regenerator 38 and the radiator 37 are disposed around the displacer head 32 so as to guide the reciprocating movement of the displacer 22 in the direction of the central axis. Therefore, the regenerator 38 and the radiator 37 also form a support part of the displacer 22. In this way, tilting of the displacer 22 with respect to the central axis can be suppressed.

The support unit 40 includes the elastic member 30 described above. The elastic member 30 is disposed between the displacer rod 34 and the expander container 20 so that an elastic restoring force acts on the displacer 22 when the displacer 22 is displaced from the neutral position. As a result, the displacer 22 reciprocates at a natural frequency determined from the spring constant of the elastic member 30, the spring constant due to the pressure of the working gas, and the weight of the displacer 22.

The elastic member 30 includes, for example, a spring mechanism including at least one leaf spring. The leaf spring is a spring called a flexure bearing, and is flexible in the reciprocating direction of the displacer 22 and rigid in the direction perpendicular to the reciprocating direction. Therefore, the displacer 22 is allowed to move in the direction along the central axis by the elastic member 30, but the movement in the direction orthogonal to the displacer 22 is restricted. The displacer rod 34 is fixed to the elastic member 30 via the elastic member mounting portion 51.

Thus, a vibration system composed of the displacer 22 and the elastic member 30 is configured. This vibration system is configured such that the displacer 22 vibrates at the same frequency as the vibration of the movable member 15 of the compressor 11 and has a phase difference with the vibration. The displacer 22 is driven by the pulsation of the working gas pressure generated in the compression space 36 by the vibration of the movable member 15 of the compressor 11. A reverse Stirling cycle is formed between the expansion space 28 and the compression space 36 by the reciprocation of the displacer 22 and the reciprocation of the movable member 15 of the compressor 11. Thus, the low temperature heat exchanger 39 adjacent to the expansion space 28 is cooled. The cooling stage 29 is cooled by the low-temperature heat exchanger 39, and the Stirling refrigerator 10 can cool the object.

Subsequently, the expander container 20 will be further described.

In addition to the cooling stage 29, the expander container 20 includes a first container part 20a, a second container part 20b, a third container part 20c, and a fourth container part 20d. The cooling stage 29, the first container part 20a, the second container part 20b, the third container part 20c, and the fourth container part 20d are arranged adjacent to each other in this order, and the inside of the expander container 20 is kept airtight. Are connected to each other.

The expander container 20 is formed in a substantially cylindrical shape, and its side wall is formed by the first container part 20a, the second container part 20b, the third container part 20c, and the fourth container part 20d. In the axial direction, one end of the expander container 20 is closed by the cooling stage 29, and the other end is closed by the fourth container portion 20d.

The first container portion 20a surrounds the regenerator 38 and the low-temperature heat exchanger 39. The second container portion 20 b surrounds the heat radiator 37. The third container portion 20 c includes a side wall portion 52 and a bottom wall portion 54 and surrounds the compression space 36. The third container portion 20 c includes a connection port 56 formed on the side wall portion 52 and connected to the connection pipe 12. The fourth container portion 20 d defines a second compartment 26.

The side wall portion 52 of the third container portion 20c includes an outer wall portion 52a and an inner wall portion 52b. The outer wall 52a and the inner wall 52b extend from the connection port 56 in the circumferential direction around the central axis. The outer wall portion 52a connects the second container portion 20b to the fourth container portion 20d. The inner wall portion 52 b connects the inner wall portion of the radiator 37 to the bottom wall portion 54. The inner wall portion 52b partitions the compression space 36 into an outer peripheral space 36a and a central space 36b. An opening 57 that connects the outer peripheral space 36a and the central space 36b is formed in the inner wall portion 52b. The openings 57 are a plurality of openings arranged at equal angular intervals in the circumferential direction. The opening 57 may be one or more slits extending in the circumferential direction.

The connection port 56 is a single opening formed on one side with respect to the central axis and penetrating the outer wall 52a and the inner wall 52b in the radial direction. The opening 57 is located between the connection port 56 and the radiator 37 in the axial direction. In the axial direction, the connection port 56 is formed on the bottom wall portion 54 side, and the opening 57 is formed between the connection port 56 and the radiator 37. The side wall 52 is formed so as to fill an annular portion 52c surrounding a region on the bottom wall 54 side of the central space 36b. Therefore, the annular portion 52 c does not serve as a gas flow path except for the connection port 56.

The bottom wall portion 54 extends radially inward from the outer wall portion 52a at the joint portion between the outer wall portion 52a and the fourth container portion 20d. A through hole through which the displacer rod 34 passes is formed at the center of the bottom wall portion 54. A rod seal is formed between the bottom wall portion 54 and the displacer rod 34.

The third container portion 20c is provided with a block 58. The block 58 is disposed in the central space 36b in contact with the inner wall portion 52b and the bottom wall portion 54.

FIG. 3 is a sectional view schematically showing the block 58 and the displacer rod 34 according to the first embodiment of the present invention. This sectional view shows a section taken along a plane perpendicular to the central axis of the displacer rod 34. The block 58 is a ring-shaped member extending over the entire circumference in the circumferential direction. A through hole 59 through which the displacer rod 34 passes is formed at the center of the block 58. The through hole 59 is a circular opening that is eccentric from the central axis of the displacer rod 34. The center of the through hole 59 is located between the center of the displacer rod 34 and the connection port 56.

The connection port 56 penetrates the block 58 at the first circumferential direction position. A first working gas region 60 of the compression space 36 is formed between the connection port 56 and the displacer rod 34 at the first circumferential position. The first working gas region 60 has a first radial width W1 between the connection port 56 and the displacer rod 34 at the first circumferential position.

Also, the second working gas region 62 of the compression space 36 is formed between the block 58 and the displacer rod 34 at a second circumferential position different from the first circumferential position. The second circumferential position is opposite to the first circumferential position with respect to the central axis of the displacer rod 34. The second working gas region 62 has a second radial width W2 between the block 58 and the displacer rod 34 at the second circumferential position.

The second radial width W2 is smaller than the first radial width W1. For example, the second radial width W2 is smaller than 2/3 of the first radial width W1, smaller than 1/2, smaller than 1/4, or smaller than 1/8.

Note that the block 58 may not be provided over the entire circumference. The block 58 may be provided only in a certain circumferential range including the second circumferential position.

As shown in FIG. 2, the axial thickness of the block 58 is shorter than the axial length from the bottom wall portion 54 to the opening 57. Therefore, the third working gas region formed between the opening 57 and the displacer rod 34 has the first radial width W1 at the second circumferential position. The axial thickness of the block 58 may be longer than the axial length from the bottom wall portion 54 to the opening 57. In this case, an opening communicating with the opening 57 may be formed in the block 58.

When the working gas flows into the expander 13, the gas flows from the connecting pipe 12 to the central space 36b through the connecting port 56. Some gases pass through the first working gas region 60 and some other gases pass through the second working gas region 62. From there, the gas flows through the opening 57 to the outer peripheral space 36a. The gas flows from the outer peripheral space 36 a into the regenerator 38 through the radiator 37. The gas flows from the regenerator 38 into the expansion space 28 and expands. The expanded gas exits from the expander 13 to the connecting pipe 12 through the reverse path.

FIG. 4 is a cross-sectional view schematically showing an expander 113 of a Stirling refrigerator. The expander 113 has substantially the same configuration as the expander 13 shown in FIG. 2 except that the expander 113 does not have the block 58. For example, the compression space 136 has a single connection port 156. The connection port 156 is connected to the compressor 11 through the connection pipe 112. The regenerator 38 is disposed around the displacer head 32 so as to guide the reciprocating movement of the displacer 22 in the direction of the central axis. The regenerator 38 forms a working gas flow path between the expansion space 28 located on one axial end side and the compression space 136 located on the other axial end side.

The gas ejected from the compressor 11 to the compression space 136 through the connection port 156 is directed toward the wall surface 158 opposite to the connection port 156 as illustrated by the arrow 72 by the momentum. The gas is directed to the radiator 37 by the wall surface 158. The gas flows into the regenerator 38 through the radiator 37. Therefore, the gas flow rate flowing into the cool storage material located on the side opposite to the connection port 156 is larger than the gas flow rate flowing into the cool storage material positioned on the connection port 156 side.

Gas flows from the regenerator 38 into the expansion space 28 and expands. As shown by the arrow 74, conversely with respect to the return gas from the expansion space 28, the gas flow rate flowing into the regenerator material located on the connection port 156 side flows into the regenerator material located on the opposite side to the connection port 156. More than the gas flow rate.

In this way, a drift is generated inside the regenerator 38. That is, a non-uniform distribution occurs in the axial gas flow in the regenerator 38. As a result, the regenerator material located on the side opposite to the connection port 156 receives more heat from the working gas than the regenerator material located on the connection port 156 side, and the regenerator 38 is circumferentially and / or radially oriented. Temperature difference occurs. Such non-uniform regenerator temperature distribution may cause an increase in pressure loss and a decrease in regenerator efficiency, and may reduce the performance of the regenerator 38. The drift and thus the refrigeration performance decrease can be significant when the operating frequency of the refrigerator is high or when the radial dimension of the refrigerator is large.

On the other hand, in the expander 13 according to this embodiment, the other part of the compression space 36 is narrower than the compression space 36 adjacent to the connection port 56. Specifically, the second working gas region 62 is narrowed by the block 58 as compared with the first working gas region 60. Therefore, the gas flow rate flowing into the regenerator 38 from the side opposite to the connection port 56 through the second working gas region 62 can be suppressed. Therefore, the expander 13 according to the present embodiment can reduce and preferably prevent the drift of the working gas that may occur in the regenerator 38. Therefore, the temperature distribution of the regenerator 38 in the plane perpendicular to the central axis is made uniform, and the refrigeration performance is improved. This performance improvement increases as the cold head temperature decreases.

FIG. 5 is a diagram schematically showing an expander 13 according to another embodiment of the present invention. The expander 13 shown in FIG. 5 is different from the expander 13 shown in FIG. 2 with respect to the displacer rod 34 and the third container portion 20c. About the other structure, the expander 13 shown by FIG. 5 is the same as that of the expander 13 shown in FIG. 2, and in order to avoid redundancy, description is abbreviate | omitted suitably.

FIG. 6 is a cross-sectional view schematically showing a displacer rod 34 according to an embodiment of the present invention. This sectional view shows a section taken along a plane perpendicular to the central axis of the displacer rod 34.

As shown in FIGS. 5 and 6, the displacer rod 34 has an elliptical shape in a cross section perpendicular to the axial direction. Accordingly, the displacer rod 34 is provided with convex portions 76 directed to the inner wall portion 52b of the third container portion 20c on both radial sides. The second working gas region 62 is formed between the inner wall portion 52b of the third container portion 20c and the convex portion 76. The convex portion 76 is formed over an axial range corresponding to the compression space 36. Since the convex part 76 is not formed in the seal part 25, the cross section of the displacer rod 34 in the seal part 25 is circular.

A first working gas region 60 is formed between the connection port 56 and the displacer rod 34 at the first circumferential position. The first working gas region 60 has a first radial width W1 between the connection port 56 and the displacer rod 34 at the first circumferential position.

Also, the second working gas region 62 is formed between the inner wall portion 52b of the third container portion 20c and the convex portion 76 of the displacer rod 34 at a second circumferential position different from the first circumferential position. The second circumferential position is a position that is 90 degrees different from the first circumferential position in the circumferential direction. The second working gas region 62 has a second radial width W2 between the inner wall portion 52b and the convex portion 76 at the second circumferential position.

The second working gas region 62 is narrowed by the convex portion 76 as compared with the first working gas region 60. Therefore, the gas flow rate flowing into the regenerator 38 from the side opposite to the connection port 56 through the second working gas region 62 can be suppressed. Therefore, the expander 13 according to the present embodiment can reduce and preferably prevent the drift of the working gas that may occur in the regenerator 38. Therefore, the temperature distribution of the regenerator 38 in the plane perpendicular to the central axis is made uniform, and the refrigeration performance is improved.

The present invention has been described above based on the embodiments. It will be understood by those skilled in the art that the present invention is not limited to the above-described embodiment, and various design changes are possible, various modifications are possible, and such modifications are within the scope of the present invention. By the way.

For example, the shape of the convex portion 76 is not limited to an ellipse, and may take other shapes such as an ellipse or a rectangle. The circumferential position of the convex portion 76 is not limited to the illustrated example, and may be any other location.

Further, the convex portion 76 may be provided only on one side of the displacer rod 34. In this case, the convex portion 76 may be directed to the side opposite to the connection port 56. Alternatively, the displacer rod 34 may include three or more protrusions.

In an embodiment, the block 58 and the convex portion 76 may be combined. That is, the expander 13 may include the third container portion 20 c including the block 58 and the displacer 22 including the convex portion 76.

In an embodiment, the displacer head 32 may include a convex portion. The convex portion may be formed on the surface of the displacer head 32 facing the compression space 36. The second working gas region 62 may be formed between the third container portion 20 c and the convex portion of the displacer head 32.

(Second Embodiment)
FIG. 7 is a diagram schematically showing a Stirling refrigerator 1010 according to the second embodiment of the present invention. The Stirling refrigerator 1010 includes a compressor 1011, a connecting pipe 1012, and an expander 1013. The Stirling refrigerator 1010 is a split type Stirling refrigerator.

The compressor 1011 includes a compressor case 1014. The compressor case 1014 is a pressure vessel configured to hold a high-pressure working gas in an airtight manner. The working gas is, for example, helium gas. Further, the compressor 1011 includes a compressor unit housed in a compressor case 1014. The compressor unit includes a compressor piston and a compressor cylinder, one of which is a movable member 1015 configured to reciprocate in the compressor case 1014, and the other is fixed to the compressor case 1014. It is a stationary member. The compressor unit includes a drive source for moving the movable member 1015 relative to the compressor case 1014 in a direction along the central axis of the movable member 1015. The compressor 1011 includes a support portion 1016 that supports the movable member 1015 on the compressor case 1014 so that the movable member 1015 can reciprocate. The movable member 1015 vibrates with respect to the compressor case 1014 and the stationary member with a certain amplitude and frequency. As a result, the volume and pressure of the working gas in the compressor 1011 also vibrate with a specific amplitude and frequency.

A working gas chamber is formed between the compressor piston and the compressor cylinder. This working gas chamber is connected to one end of the connection pipe 1012 through a communication passage formed in the stationary member and the compressor case 1014 described above. The other end of the connection pipe 1012 is connected to the working gas receiving chamber of the expander 1013. In this way, the working gas chamber of the compressor 1011 is connected to the working gas receiving chamber of the expander 1013 by the connecting pipe 1012.

The expander 1013 includes an expander container 1020, a displacer 1022, and at least one support portion 1040, as will be described later with reference to FIG.

FIG. 8 is a diagram schematically showing an expander 1013 according to the second embodiment of the present invention. FIG. 8 shows an outline of the internal structure of the expander 1013.

The expander container 1020 is a pressure container configured to hold a high-pressure working gas in an airtight manner. This pressure vessel may be composed of a plurality of vessel parts connected to each other so as to keep the inside airtight. The displacer 1022 is a movable member configured to reciprocate within the expander container 1020. The support unit 1040 supports the displacer 1022 on the expander container 1020 so that the displacer 1022 can reciprocate.

The expander container 1020 includes a first compartment 1024 and a second compartment 1026. The first compartment 1024 includes an expansion space 1028 and a compression space 1036 for working gas formed between the expander vessel 1020 and the displacer 1022. A portion of the expander container 1020 adjacent to the expansion space 1028 is provided with a cooling stage 1029 for cooling the object. The cooling stage 1029 is also called a cold head. The second section 1026 is configured to support the displacer 1022 on the expander container 1020 via the elastic member 1030.

The second section 1026 is adjacent to the first section 1024 in the reciprocating direction of the displacer 1022 (indicated by arrow C in the figure). A seal portion 1025 is provided between the second compartment 1026 and the first compartment 1024, so that the second compartment 1026 is partitioned from the first compartment 1024. Thus, the pressure fluctuations of the working gas in the first compartment 1024 are not transmitted to the second compartment 1026 or do not significantly affect the pressure of the working gas in the second compartment 1026. Note that the second compartment 1026 is filled with the same type of gas as the working gas so as to have a pressure equivalent to the average pressure of the working gas flowing through the connecting pipe 1012.

The displacer 1022 includes a displacer head 1032 accommodated in the first section 1024 and a displacer rod 1034. Displacer rod 1034 is a shaft portion thinner than displacer head 1032. The displacer 1022 has a central axis (indicated by the alternate long and short dash line A) in the reciprocating direction, and the displacer head 1032 and the displacer rod 1034 are provided coaxially with the central axis of the displacer 1022. The displacer head 1032 has a cavity inside and is filled with the same kind of gas as the working gas.

Displacer rod 1034 extends from displacer head 1032 through seal 1025 to second compartment 1026. The displacer rod 1034 is supported by the expander vessel 1020 in the second compartment 1026 to allow the displacer 1022 to reciprocate. The seal portion 1025 described above may be a rod seal formed between the displacer rod 1034 and the expander container 1020, for example. The displacer rod 1034 also has a cavity inside, similar to the displacer head 1032. The cavity of the displacer rod 1034 is connected to the cavity of the displacer head 1032. The distal end of the displacer rod 1034 may be open, and the internal cavity of the displacer 1022 may be in communication with the second compartment 1026.

The first section 1024 forms a cylinder portion that surrounds the displacer head 1032. An expansion space 1028 is formed between the bottom surface of the cylinder portion (that is, the inner surface of the cooling stage 1029) and the distal end surface 1032a of the displacer head 1032. The expansion space 1028 is formed on the side opposite to the joint between the displacer head 1032 and the displacer rod 1034 in the reciprocating direction of the displacer 1022. A working gas compression space 1036 in the expander 1013 is formed between the joint portion and the seal portion 1025. Therefore, the displacer head 1032 faces the expansion space 1028 on one end side in the axial direction and faces the compression space 1036 on the other end side in the axial direction. The compression space 1036 is a working gas receiving chamber of the expander 1013 connected to the compressor 1011 through the connection pipe 1012.

In the cylinder portion of the expander container 1020, a regenerator 1038 is provided adjacent to the radially outer side of the displacer head 1032. Here, the radial direction refers to a direction perpendicular to the direction of the central axis. Thus, the regenerator 1038 is accommodated in the expander container 1020. The regenerator 1038 extends in the axial direction coaxially with the displacer 1022 and is formed in an annular or donut shape. More specifically, the regenerator 1038 is provided on the side surface of the cylinder portion of the expander container 1020 so as to be positioned in a cylindrical region around the longitudinal axis of the displacer 1022 in the outer peripheral portion of the displacer head 1032. . The regenerator 1038 includes, for example, a laminated structure of wire mesh as a regenerator material. The working gas can be circulated between the expansion space 1028 and the compression space 1036 through the regenerator 1038. The expansion space 1028 is located on one end side of the regenerator 1038 in the direction of the central axis, and the compression space 1036 is located on the other end side of the regenerator 1038 in the direction of the central axis.

A radiator 1037 is provided adjacent to the regenerator 1038 between the regenerator 1038 and the compression space 1036 in the axial direction. The radiator 1037 is, for example, a water-cooled heat exchanger. Similarly to the regenerator 1038, the radiator 1037 is formed in an annular shape or a donut shape. The radiator 1037 forms a cylinder part together with the regenerator 1038.

The heat radiator 1037 cools the working gas supplied from the compressor 1011 and realizes heat exchange for releasing the heat to the outside of the expander 1013. Since the working gas supplied from the compressor 1011 to the compression space 1036 generally has a temperature higher than room temperature, the radiator 1037 cools the high-temperature gas to about room temperature.

The heat radiator 1037 is disposed around the displacer head 1032. The side surface of the displacer head 1032 is slidable with the inner wall portion of the radiator 1037, whereby the radiator 1037 can guide the reciprocating movement of the displacer head 1032 in the axial direction. A seal portion that prevents the working gas from flowing through the compression space 1036 and the expansion space 1028 may be formed between the side surface of the displacer head 1032 and the inner wall portion of the radiator 1037.

In addition, a low-temperature heat exchanger 1039 is attached adjacent to the regenerator 1038 between the regenerator 1038 and the cooling stage 1029 in the axial direction. The low temperature heat exchanger 1039 is disposed around the displacer tip. A working gas flow path connecting the compression space 1036 and the expansion space 1028 is formed by the radiator 1037, the regenerator 1038, and the low temperature heat exchanger 1039. A minute clearance may be formed between the regenerator 1038 and the displacer head 1032 in the radial direction. Similarly, a minute clearance may be formed between the low-temperature heat exchanger 1039 and the displacer head 1032 in the radial direction.

The expander 1013 supports the displacer 1022 on the expander container 1020 so that the displacer 1022 can reciprocate at a plurality of different positions in the reciprocating direction of the displacer 1022. For this purpose, the expander 1013 includes two support portions 1040. These two support portions 1040 are provided in the second section 1026. Further, as described above, the regenerator 1038 and the radiator 1037 are disposed around the displacer head 1032 so as to guide the reciprocating movement of the displacer 1022 in the direction of the central axis. Thus, the regenerator 1038 and the radiator 1037 also form a support for the displacer 1022. In this way, the tilt of the displacer 1022 with respect to the central axis can be suppressed.

The support portion 1040 includes the elastic member 1030 described above. The elastic member 1030 is disposed between the displacer rod 1034 and the expander container 1020 so that an elastic restoring force acts on the displacer 1022 when the displacer 1022 is displaced from the neutral position. Accordingly, the displacer 1022 reciprocates at a natural frequency determined from the spring constant of the elastic member 1030, the spring constant resulting from the pressure of the working gas, and the weight of the displacer 1022.

The elastic member 1030 includes, for example, a spring mechanism including at least one leaf spring. The leaf spring is a spring called a flexure bearing and is flexible in the reciprocating direction of the displacer 1022 and rigid in the direction perpendicular to the reciprocating direction. Accordingly, the displacer 1022 is allowed to move in the direction along the central axis by the elastic member 1030, but the movement in the direction orthogonal thereto is restricted. The displacer rod 1034 is fixed to the elastic member 1030 via the elastic member mounting portion 1051.

Thus, a vibration system including the displacer 1022 and the elastic member 1030 is configured. This vibration system is configured such that the displacer 1022 vibrates at the same frequency as the vibration of the movable member 1015 of the compressor 1011 and has a phase difference with the vibration. The displacer 1022 is driven by the pulsation of the working gas pressure generated in the compression space 1036 by the vibration of the movable member 1015 of the compressor 1011. A reverse Stirling cycle is formed between the expansion space 1028 and the compression space 1036 by the reciprocation of the displacer 1022 and the reciprocation of the movable member 1015 of the compressor 1011. Thus, the low temperature heat exchanger 1039 adjacent to the expansion space 1028 is cooled. The cooling stage 1029 is cooled by the low-temperature heat exchanger 1039, and the Stirling refrigerator 1010 can cool the object.

Subsequently, the configuration of the connection pipe 1012 and the expander container 1020 will be further described.

The connection pipe 1012 includes a main pipe 1060, a first branch pipe 1062, and a second branch pipe 1064. The main pipe 1060 is connected to the compressor 1011 at one end and includes a branching portion 1066 at the other end. The first branch pipe 1062 branches off from the main pipe 1060 at the branch portion 1066. Similarly, the second branch pipe 1064 branches from the main pipe 1060 at the branch portion 1066.

The expander container 1020 includes a first container part 1020a, a second container part 1020b, a third container part 1020c, and a fourth container part 1020d in addition to the cooling stage 1029. The cooling stage 1029, the first container part 1020a, the second container part 1020b, the third container part 1020c, and the fourth container part 1020d are arranged adjacent to each other in this order, and the inside of the expander container 1020 is kept airtight. Are connected to each other.

The expander container 1020 is generally formed in a cylindrical shape, and its side wall is formed by the first container part 1020a, the second container part 1020b, the third container part 1020c, and the fourth container part 1020d. In the axial direction, one end of the expander container 1020 is closed by the cooling stage 1029, and the other end is closed by the fourth container portion 1020d.

The first container portion 1020a surrounds the regenerator 1038 and the low temperature heat exchanger 1039. The second container portion 1020 b surrounds the heat radiator 1037. The third container portion 1020 c includes a side wall portion 1052 and a bottom wall portion 1054 and surrounds the compression space 1036. The side wall part 1052 connects the second container part 1020b to the fourth container part 1020d. Side wall portion 1052 extends in the circumferential direction around the central axis. The bottom wall portion 1054 extends radially inward from the side wall portion 1052 at the joint portion between the side wall portion 1052 and the fourth container portion 1020d. A through hole through which the displacer rod 1034 passes is formed at the center of the bottom wall portion 1054. A rod seal is formed between the bottom wall portion 1054 and the displacer rod 1034. The fourth container portion 1020d defines a second compartment 1026.

The third container portion 1020c includes a first connection port 1056 formed on one side with respect to the central axis, and a second connection port 1058 formed on the other side with respect to the central axis. The first connection port 1056 is formed in the side wall portion 1052. The second connection port 1058 is formed in the side wall portion 1052 so as to face the first connection port 1056 across the central axis. The first connection port 1056 and the second connection port 1058 are formed at intervals of 180 degrees in the circumferential direction. The first connection port 1056 and the second connection port 1058 are formed point-symmetrically with respect to the central axis on a plane perpendicular to the central axis.

The first branch pipe 1062 is connected to the first connection port 1056. Similarly, the second branch pipe 1064 is connected to the second connection port 1058. The first branch pipe 1062 extends from the first connection port 1056 to the branch portion 1066 outward in the radial direction. The second branch pipe 1064 includes an outlet portion 1064a extending from the second connection port 1058 outward in the radial direction, and a connecting portion 1064b connecting the outlet portion 1064a to the branch portion 1066. The connecting portion 1064b extends from the branch portion 1066 to the outlet portion 1064a along the outer surface of the fourth container portion 1020d. Thus, the compression space 1036 of the expander 1013 is connected to the compressor 1011 through a plurality of connection ports.

When the working gas flows from the compressor 1011 into the compression space 1036 of the expander 1013, the first connection port 1056 generates a first gas flow 1068 directed toward the central axis. At this time, the second connection port 1058 generates a second gas flow 1070 toward the central axis in the opposite direction to the first gas flow 1068. Thus, the connecting pipe 1012 is connected to the expander container 1020 so as to generate a plurality of working gas flows in the compression space 1036 each directed toward the central axis of the regenerator 1038.

Note that the branching portion 1066 may be provided on the second connection port 1058 side. In this case, the second branch pipe 1064 may extend from the second connection port 1058 to the branch portion 1066 outward in the radial direction. The first branch pipe 1062 may include an outlet portion that extends radially outward from the first connection port 1056 and a connection portion that connects the outlet portion to the branch portion 1066.

Alternatively, each of the first branch pipe 1062 and the second branch pipe 1064 includes an outlet portion extending radially outward from a corresponding connection port, and a connection portion connecting the outlet portion to the branch portion 1066. Also good. In this case, the first branch pipe 1062 and the second branch pipe 1064 may be configured such that the pressure loss of the working gas in the first branch pipe 1062 is equal to the pressure loss of the working gas in the second branch pipe 1064. . For example, the first branch pipe 1062 and the second branch pipe 1064 may have equal paths, lengths, and / or cross-sectional areas.

Further, the connection portion of the first branch pipe 1062 and / or the second branch pipe 1064 may extend in the circumferential direction along the outer surface of the third container portion 1020c.

FIG. 9 is a cross-sectional view schematically showing an expander 1113 of a Stirling refrigerator. The expander 1113 has a single connection port 1156 in the compression space 1136. The connection port 1156 is connected to the compressor 1011 through a non-branching connection pipe 1112.

Other configurations of the expander 1113 are substantially the same as those of the expander 1013 shown in FIG. For example, the regenerator 1038 is disposed around the displacer head 1032 to guide the reciprocating movement of the displacer 1022 in the direction of the central axis. The regenerator 1038 forms a working gas flow path between the expansion space 1028 located on one axial end side and the compression space 1136 located on the other axial end side.

The gas ejected from the compressor 1011 to the compression space 1136 through the connection port 1156 is directed toward the wall surface 1158 on the opposite side of the connection port 1156 as shown by the arrow 1072 by the momentum. The gas is directed to the radiator 1037 by the wall 1158. The gas flows into the regenerator 1038 through the radiator 1037. Therefore, the gas flow rate flowing into the cool storage material located on the side opposite to the connection port 1156 is larger than the gas flow rate flowing into the cool storage material positioned on the connection port 1156 side.

Gas flows from the regenerator 1038 into the expansion space 1028 and expands. Contrary to the return gas from the expansion space 1028, the gas flow rate flowing into the regenerator material located on the connection port 1156 side flows into the regenerator material located on the opposite side to the connection port 1156, as shown by the arrow 1074. More than the gas flow rate.

In this way, a drift is generated inside the regenerator 1038. That is, non-uniform distribution occurs in the axial gas flow in the regenerator 1038. As a result, the regenerator material located on the side opposite to the connection port 1156 receives more heat from the working gas than the regenerator material located on the connection port 1156 side, and the regenerator 1038 receives the heat in the circumferential direction and / or radial direction. Temperature difference occurs. Such a non-uniform regenerator temperature distribution may cause an increase in pressure loss and a decrease in regenerator efficiency, and may reduce the performance of the regenerator 1038. The drift and thus the refrigeration performance decrease can be significant when the operating frequency of the refrigerator is high or when the radial dimension of the refrigerator is large.

On the other hand, in the expander 1013 according to this embodiment, as shown in FIG. 8, the first gas flow 1068 and the second gas flow 1070 facing the first gas flow 1070 collide with each other at the center of the compression space 1036. , The momentum is suppressed. Therefore, the expander 1013 according to the present embodiment can reduce and preferably prevent the drift of the working gas that may occur in the regenerator 1038. Therefore, the temperature distribution of the regenerator 1038 in the plane perpendicular to the central axis is made uniform, and the refrigeration performance is improved. This performance improvement increases as the cold head temperature decreases.

For example, one or more connection ports may be formed on one side with respect to the central axis of the regenerator, and one or more connection ports may be formed on the other side with respect to the central axis of the regenerator. Thus, three or more connection ports may be formed. The connection ports may be formed at equiangular intervals. For example, one connection port may be formed on one side, two connection ports may be formed on the other side, and these three connection ports may be formed at intervals of 120 degrees in the circumferential direction. That is, the connection ports may be arranged in a regular triangle shape when viewed in the axial direction. In this case, the connection ports do not face each other across the central axis. Alternatively, the four connection ports may be formed at intervals of 90 degrees in the circumferential direction, the first set of connection ports facing each other across the central axis, and the second set of connection ports facing each other across the central axis.

The plurality of connection ports may not be formed at equiangular intervals. For example, a first group of connection ports composed of a plurality of connection ports is formed on one side with respect to the central axis of the regenerator, and a second group of connection ports composed of a plurality of connection ports is defined relative to the center axis of the regenerator It may be formed on the other side. The connection ports of the first group may be arranged close to each other in the circumferential direction. Similarly, the connection ports of the second group may be arranged close to each other in the circumferential direction. Thus, the connection port of the first group and the connection port of the second group may face each other.

The first connection port 1056, the second connection port 1058, and / or other connection ports may be formed not on the side wall portion 1052 but on the bottom wall portion 1054. In this case, the connection pipe corresponding to the connection port formed in the bottom wall portion 1054 may be connected to the connection port through the fourth container portion 1020d and the second section 1026.

As shown in FIG. 10, the Stirling refrigerator may include a plurality of compressors 1011. In this case, a connection pipe 1012 ′ and a connection port 1056 ′ may be provided for each compressor 1011. The connecting pipe 1012 ′ may be a pipe that does not have a branch portion.

Alternatively, as in the above-described embodiment, the connection pipe 1012 ′ corresponding to each compressor 1011 may have a branch portion. In this case, the connecting pipe 1012 ′ has a plurality of branch pipes that branch from the main pipe at the branch portion. Each of the branch pipes may be connected to a corresponding connection port.

In an embodiment, the regenerator may be built in the displacer. In this case, the expander container may include a container part surrounding the compression space adjacent to the displacer with a built-in regenerator. The container portion may include one or more connection ports formed on one side with respect to the displacer central axis and one or more connection ports formed on the other side with respect to the displacer central axis. A corresponding branch pipe or an unbranched connection pipe may be connected to each of the connection ports.

The Stirling refrigerator according to an embodiment may be a Stirling pulse tube refrigerator.

The embodiment of the present invention can also be expressed as follows.

1. An expander, a compressor, and a connecting pipe connecting the compressor to the expander,
The expander is
A displacer extending in the axial direction, facing the working gas expansion space on one end side in the axial direction and facing the working gas compression space on the other end side in the axial direction;
A regenerator disposed around the displacer to guide reciprocating movement of the displacer in the axial direction and forming a working gas flow path between the working gas compression space and the working gas expansion space;
An expander container that houses the displacer and the regenerator, and has a connection port that is formed at a first circumferential position and connects the working gas compression space to the connection pipe, and extends from the connection port in the circumferential direction. An expander vessel including a vessel portion existing and surrounding the working gas compression space;
A first working gas region of the working gas compression space is formed between the connection port and the displacer at the first circumferential position, and the first working gas region is formed at the connection port at the first circumferential position. And a first radial width between the displacer and
A second working gas region of the working gas compression space is formed between the container portion and the displacer at a second circumferential position different from the first circumferential position, and the second working gas region is the second working gas region. Having a second radial width between the container portion and the displacer at a circumferential position;
The Stirling refrigerator, wherein the second radial width is smaller than the first radial width.

2. The container portion includes a block extending in a circumferential range including the second circumferential position;
The Stirling refrigerator according to the first embodiment, wherein the second working gas region is formed between the block and the displacer.

3. The displacer includes a convex portion that is directed radially toward the container portion in a cross section perpendicular to the axial direction,
The Stirling refrigerator according to Embodiment 1 or 2, wherein the second working gas region is formed between the container portion and the convex portion.

4). The displacer comprises a displacer head having a displacer tip surface facing the working gas expansion space, and a displacer rod extending from the displacer head in the axial direction to the working gas compression space,
The regenerator is disposed around the displacer head,
The first working gas region is formed between the connection port and the displacer rod, and the second working gas region is formed between the container portion and the displacer rod. The Stirling refrigerator according to any one of Embodiments 1 to 3.

5. An expander, a compressor, and a connecting pipe connecting the compressor to the expander,
The expander is
A regenerator extending in the direction of the central axis, the working gas expansion space located on one end side of the regenerator in the direction of the central axis and the other end side of the regenerator in the direction of the central axis A regenerator that forms a working gas flow path between the working gas compression space;
An expander container containing the regenerator, the expander container including a container portion surrounding the working gas compression space, and
The connecting pipe is
A main pipe connected to the compressor at one end and having a branching portion at the other end;
A first branch pipe branched from the main pipe at the branch portion;
A second branch pipe branched from the main pipe at the branch portion,
The container portion is formed on one side with respect to the central axis and connected to the first branch pipe, and is formed on the other side with respect to the central axis and connected to the second branch pipe. And a second connection port.

6). The container portion includes a side wall extending around the central axis;
The Stirling refrigerator according to the fifth embodiment, wherein the first connection port and the second connection port are formed in the side wall portion so as to face each other across the central axis.

7). The expander further comprises a displacer extending along the central axis,
The displacer includes a displacer head facing the working gas expansion space on one axial end side and facing the working gas compression space on the other axial end side,
The Stirling refrigerator according to embodiment 5 or 6, wherein the regenerator is disposed around the displacer head so as to guide reciprocal movement of the displacer in the direction of the central axis.

8). An expander, at least one compressor, and at least one connecting pipe connecting the at least one compressor to the expander,
The expander is
A regenerator extending in the direction of the central axis, the working gas compression space located on one end side of the regenerator in the direction of the central axis and located on the other end side of the regenerator in the direction of the central axis A regenerator that forms a working gas flow path between the working gas expansion space;
An expander container containing the regenerator, the expander container including a container portion surrounding the working gas compression space, and
The container portion is formed on one side with respect to the central axis and connected to the connecting pipe, and the second connection is formed on the other side with respect to the central axis and connected to the connecting pipe. And a Stirling refrigerator having a mouth.

9. The container portion includes a side wall extending around the central axis;
The Stirling refrigerator according to the eighth embodiment, wherein the first connection port and the second connection port are formed in the side wall portion so as to face each other across the central axis.

10. The Stirling refrigerator includes a single compressor and a single connection pipe that connects the single compressor to the expander,
The connecting pipe is
A main pipe connected to the compressor at one end and having a branching portion at the other end;
A first branch pipe branched from the main pipe at the branch portion and connected to the first connection port;
The Stirling refrigerator according to Embodiment 8 or 9, further comprising: a second branch pipe branched from the main pipe at the branch portion and connected to the second connection port.

11. The expander further comprises a displacer extending along the central axis,
The displacer includes a displacer head facing the working gas expansion space on one axial end side and facing the working gas compression space on the other axial end side,
The Stirling refrigerator according to any one of Embodiments 8 to 10, wherein the regenerator is disposed around the displacer head so as to guide reciprocal movement of the displacer in the direction of the central axis. .

10 Stirling refrigerator, 11 compressor, 12 connecting pipe, 13 expander, 20 expander container, 22 displacer, 28 expansion space, 32 displacer head, 34 displacer rod, 36 compression space, 36a outer space, 36b central space, 37 Radiator, 38 regenerator, 52 side wall, 52a outer wall, 52b inner wall, 54 bottom wall, 56 connection port, 57 opening, 58 block, 59 through hole, 60 first working gas region, 62 second operation Gas region, 76 convex part, 1010 Stirling refrigerator, 1011 compressor, 1012 connecting pipe, 1013 expander, 1020 expander container, 1020a first container part, 1020b second container part, 10 0c 3rd container part, 1020d 4th container part, 1022 displacer, 1028 expansion space, 1032 displacer head, 1036 compression space, 1038 regenerator, 1052 side wall, 1056 first connection port, 1058 second connection port, 1060 main pipe, 1062 1st branch pipe, 1064 2nd branch pipe, 1066 Branching part.

The present invention can be used in the field of Stirling refrigerators.

Claims

An expander, a compressor, and a connecting pipe connecting the compressor to the expander,
The expander is
A displacer extending in the axial direction, facing the working gas expansion space on one end side in the axial direction and facing the working gas compression space on the other end side in the axial direction;
A regenerator disposed around the displacer to guide reciprocating movement of the displacer in the axial direction and forming a working gas flow path between the working gas compression space and the working gas expansion space;
An expander container that houses the displacer and the regenerator, and has a connection port that is formed at a first circumferential position and connects the working gas compression space to the connection pipe, and extends from the connection port in the circumferential direction. An expander vessel including a vessel portion existing and surrounding the working gas compression space;
A first working gas region of the working gas compression space is formed between the connection port and the displacer at the first circumferential position, and the first working gas region is formed at the connection port at the first circumferential position. And a first radial width between the displacer and
A second working gas region of the working gas compression space is formed between the container portion and the displacer at a second circumferential position different from the first circumferential position, and the second working gas region is the second working gas region. Having a second radial width between the container portion and the displacer at a circumferential position;
The Stirling refrigerator, wherein the second radial width is smaller than the first radial width.
The container portion includes a block extending in a circumferential range including the second circumferential position;
The Stirling refrigerator according to claim 1, wherein the second working gas region is formed between the block and the displacer.
The displacer includes a convex portion that is directed radially toward the container portion in a cross section perpendicular to the axial direction,
The Stirling refrigerator according to claim 1 or 2, wherein the second working gas region is formed between the container portion and the convex portion.
The displacer comprises a displacer head having a displacer tip surface facing the working gas expansion space, and a displacer rod extending from the displacer head in the axial direction to the working gas compression space,
The regenerator is disposed around the displacer head,
The first working gas region is formed between the connection port and the displacer rod, and the second working gas region is formed between the container portion and the displacer rod. The Stirling refrigerator according to any one of claims 1 to 3.
An expander, a compressor, and a connecting pipe connecting the compressor to the expander,
The expander is
A regenerator extending in the direction of the central axis, the working gas expansion space located on one end side of the regenerator in the direction of the central axis and the other end side of the regenerator in the direction of the central axis A regenerator that forms a working gas flow path between the working gas compression space;
An expander container containing the regenerator, the expander container including a container portion surrounding the working gas compression space, and
The connecting pipe is
A main pipe connected to the compressor at one end and having a branching portion at the other end;
A first branch pipe branched from the main pipe at the branch portion;
A second branch pipe branched from the main pipe at the branch portion,
The container portion is formed on one side with respect to the central axis and connected to the first branch pipe, and is formed on the other side with respect to the central axis and connected to the second branch pipe. And a second connection port.
The container portion includes a side wall extending around the central axis;
6. The Stirling refrigerator according to claim 5, wherein the first connection port and the second connection port are formed in the side wall portion so as to face each other with the central axis interposed therebetween.
The expander further comprises a displacer extending along the central axis,
The displacer includes a displacer head facing the working gas expansion space on one axial end side and facing the working gas compression space on the other axial end side,
The Stirling refrigerator according to claim 5 or 6, wherein the regenerator is disposed around the displacer head so as to guide reciprocal movement of the displacer in the direction of the central axis.
An expander, at least one compressor, and at least one connecting pipe connecting the at least one compressor to the expander,
The expander is
A regenerator extending in the direction of the central axis, the working gas compression space located on one end side of the regenerator in the direction of the central axis and located on the other end side of the regenerator in the direction of the central axis A regenerator that forms a working gas flow path between the working gas expansion space;
An expander container containing the regenerator, the expander container including a container portion surrounding the working gas compression space, and
The container portion is formed on one side with respect to the central axis and connected to the connecting pipe, and the second connection is formed on the other side with respect to the central axis and connected to the connecting pipe. And a Stirling refrigerator having a mouth.