Split Stirling expander

Abstract

The split Stirling expander of the present invention includes a housing unit and a moving unit. The housing unit includes a bottom housing, a middle housing, a slit heat exchanger, an expansion cylinder, a lining sleeve, and a cold head that are connected in sequence. One end of the slit heat exchanger is connected to one end of the expansion cylinder. The lining sleeve is arranged in the middle housing, and the side surface and the end surface of the lining sleeve are respectively connected to the middle housing and a small disc. The moving unit includes an expander leaf spring, an ejector rod, and a regenerator housing. The expander leaf spring is fixedly connected to the lining sleeve. One end of the regenerator housing is arranged in the lining sleeve, and the other end is arranged in a cylindrical cylinder. The ejector rod is arranged in the lining sleeve. The expander of the present invention cancels the traditional water-cooled jacket structure and uses a hot-end slit heat exchanger instead. The gas working medium releases enough heat to the environment through the hot-end heat exchanger. By changing parameters such as the number and width of the slits of the hot-end heat exchanger, the requirements for the heat dissipation of the gas working medium by the expander under different working conditions can be met.

Description

Technical Field

[0001] The present invention belongs to the field of refrigeration, and particularly relates to a split Stirling expander. Background Art

[0002] Since the development of cryogenic refrigerators to date, they have been widely used in commercial, military, and space refrigeration fields. As a typical type of regenerative cryogenic refrigerator, Stirling refrigerators were initially applied in fields such as aerospace, superconducting filtering, and infrared detection. Compared with traditional vapor compression refrigeration, Stirling refrigerators have many advantages such as environmentally friendly refrigerants, no working direction restrictions, compact structure, high efficiency, and reliability.

[0003] Classified according to the connection method between the expansion chamber and the compression chamber, Stirling refrigerators can be divided into split type and integral type. The split Stirling refrigerator is developed on the basis of the research of the integral Stirling refrigerator. The split Stirling refrigerator completely separates the compressor from the expander and uses a thin tube to connect the two, which can avoid or reduce the influence of compressor vibration on the cold head, enabling the cooled device (such as an infrared detector) to be far from the vibration source. Most current split Stirling refrigerators use a double-piston opposed linear compressor, which balances the momentum of the motor mover, simplifies the structure, reduces vibration and noise, and improves the practicality and performance of the refrigerator.

[0004] The expander of the current split Stirling refrigerator mainly consists of an expander housing, a regenerator, an expansion piston, a leaf spring, and a cold finger part, etc. The movement of the expansion piston is driven by the periodic pressure wave transmitted from the compressor through the connecting pipe. Its displacement forms a certain phase angle with the pressure wave to generate cooling capacity. After the refrigerant driven by the pressure wave enters the expander, it will go through a process of dissipating heat to the environment, releasing heat to the regenerator packing, absorbing heat in the cold cavity for refrigeration, returning to the regenerator to absorb the heat of the packing, and finally returning to the compressor to complete a cycle. In fact, affected by the housing structure and environmental temperature, the heat dissipation of the gas to the environment is small, and the working medium gas entering the regenerator is not cooled to the expected temperature, resulting in a decline in the performance of the refrigerator. Currently, most split Stirling refrigerator expanders use an outer jacket water-cooled radiator to solve this problem, but using this type of radiator will increase external devices such as a constant temperature water tank and a water pump, increasing the volume of the entire Stirling refrigerator equipment and greatly reducing the reliability. For occasions with small cooling capacity requirements, in order to streamline the structure and optimize the volume, the expander often does not have a hot end radiator, resulting in a decrease in refrigeration efficiency. Summary of the Invention

[0005] In order to solve the above problems, the present invention designs a split Stirling refrigerator expander that can simplify the structure and improve the refrigeration performance.

[0006] The present invention provides a split Stirling expander, which has the following characteristics. It includes a housing unit and a moving unit. Among them, the housing unit includes a bottom housing, a middle housing, a slit heat exchanger, an expansion cylinder, and a liner sleeve connected in sequence. The slit heat exchanger is in the shape of a flange plate, having a connected large ring plate and a small ring plate. A protruding cylindrical cylinder is provided in the middle of the expansion cylinder. One end of the bottom housing is connected to one end of the middle housing, the other end of the middle housing is connected to one end of the large ring plate of the slit heat exchanger, and the other end of the large ring plate of the slit heat exchanger is connected to one end of the expansion cylinder.

[0007] The liner sleeve is arranged in the middle housing, and the side surface and end surface of the liner sleeve are respectively connected to the middle housing and the small ring plate. The moving unit includes an expander leaf spring, an ejector rod, and a regenerator housing. The expander leaf spring is fixedly connected to the liner sleeve. One end of the regenerator housing is arranged in the liner sleeve, and the other end is arranged in the cylindrical cylinder. The ejector rod is arranged in the liner sleeve, with one end connected to the expander leaf spring and the other end connected to one end of the regenerator housing.

[0008] In the split Stirling expander provided by the present invention, it may also have the following characteristics: Among them, a cylindrical cavity and a plurality of slits are provided in the middle of the slit heat exchanger. The plurality of slits are evenly arranged along the circumference of the cylindrical cavity, and the slits extend radially outward from the inner wall surface of the cylindrical cavity.

[0009] In addition, in the split Stirling expander provided by the present invention, it may also have the following characteristics: Among them, the slits extend radially outward from the inner wall surface of the cylindrical cavity to between the large ring plate and the small ring plate.

[0010] In addition, in the split Stirling expander provided by the present invention, it may also have the following characteristics: Among them, the number of slits is 20 - 35.

[0011] In addition, in the split Stirling expander provided by the present invention, it may also have the following characteristics: Among them, a plurality of through holes are arranged along the circumference on the regenerator housing.

[0012] In addition, in the split Stirling expander provided by the present invention, it may also have the following characteristics: Among them, the through holes are arc-shaped, and the number is 3 - 6. When the operating condition of the expander is in a balanced state, the through holes are in the bottom inner cavity of the expansion cylinder. The distance between the upper end surface of the through hole and the bottom end surface of the expansion cylinder is the same as the movement amplitude of the regenerator housing, and the distance between the lower end surface of the through hole and the top end surface of the liner sleeve is the same as the movement amplitude of the regenerator housing.

[0013] In addition, in the split Stirling expander provided by the present invention, it may also have the following characteristics: Among them, the ejector rod and the regenerator housing are fixedly connected by bolts.

[0014] In addition, in the split Stirling expander provided by the present invention, it may further have the following feature: A sealing ring is also provided between the middle housing and the inner lining sleeve.

[0015] In addition, in the split Stirling expander provided by the present invention, it may further have the following feature: A wear-resistant material for sealing is provided on the outer wall surface of the regenerator housing to reduce the axial heat conduction loss of the regenerator.

[0016] Functions and Effects of the Invention

[0017] According to the split Stirling expander involved in the present invention, the expander cancels the external water-cooling jacket structure of the expander of the traditional split Stirling refrigerator, and designs a hot-end slit heat exchanger that matches the basic components of the expander to replace it. The gas working medium releases enough heat to the environment through the hot-end heat exchanger. By changing parameters such as the number and width of the slits of the hot-end heat exchanger, the requirements for the heat dissipation of the gas working medium by the expander under different working conditions can be met.

[0018] The expander optimizes the structures of the expander housing, the displacer rod, and the regenerator housing, so that the regenerator is included in the expansion piston assembly. The structure is simple, convenient for processing and manufacturing, reduces the dead volume, as well as the pumping loss, shuttle loss, and axial heat conduction loss in the structure of the traditional expander, thereby reducing the weight and volume of the entire Stirling device, and improving the refrigeration performance and reliability. Description of the Drawings

[0019] Figure 1 It is a schematic cross-sectional view of the split Stirling expander in this embodiment;

[0020] Figure 2 It is a three-dimensional cross-sectional view of the split Stirling expander in this embodiment;

[0021] Figure 3 It is a partial three-dimensional cross-sectional view of the regenerator housing in this embodiment;

[0022] Figure 4 It is Figure 1 A partial enlarged view of A in

[0023] Figure 5 It is a front view schematic diagram of the slit heat exchanger in this embodiment;

[0024] Figure 6 It is an isometric schematic diagram of the slit heat exchanger in this embodiment;

[0025] Figure 7 It is a schematic diagram of the local flow of the working medium gas when the regenerator housing is in the equilibrium position in this embodiment;

[0026] Figure 8Schematic diagram of the local flow of the working fluid gas when the regenerator housing is at the bottom dead center position in this embodiment;

[0027] Figure 9 Schematic diagram of the local flow of the working fluid gas when the regenerator housing is at the top dead center position in this embodiment;

[0028] Figure 10 Partial cross-sectional schematic diagram of the split Stirling expander in the second embodiment of this invention;

[0029] Figure 11 Schematic diagram of the clearance seal in this embodiment;

[0030] Figure 12 is Figure 11 Local enlarged view of B in; and

[0031] Figure 13 is Figure 11 Local enlarged view of C in. Detailed implementation mode

[0032] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the following embodiments will specifically elaborate on the split Stirling expander of the present invention in conjunction with the accompanying drawings.

[0033] Embodiment 1

[0034] The split Stirling expander includes a housing unit, a moving unit and a shock absorber unit.

[0035] As Figure 1 and Figure 2 shown,

[0036] The housing unit includes a bottom housing 2, a middle housing 5, a slit heat exchanger 6, an expansion cylinder 8, and a lining sleeve 3 and a cold head 11 that are connected in sequence.

[0037] In the embodiment, the bottom housing 2 is disc-shaped.

[0038] The middle housing 5 is cylindrical with openings at both ends and has two connected coaxial cylindrical cavities inside, and the diameters of the two cavities are different. The end with the larger cavity diameter is connected to the bottom housing 2, and the bottom housing 2 and the middle housing 5 are welded and connected at the welding joint 201.

[0039] As Figure 5 、 6As shown, the slit heat exchanger 6 is a hot-end heat exchanger, sandwiched between the middle housing 5 and the expansion cylinder 8. The slit heat exchanger 6 is in the shape of a flange plate, having a connected large disk and small disk. In the embodiment, it is in a segmented circular ring shape, divided into two segments in total. The two circular rings are concentric, with the same inner diameter, and a cylindrical cavity is formed in the center for accommodating the reciprocating displacer rod 4 and the regenerator housing 9. The outer diameter of the left segment circular ring is slightly smaller, and the outer wall surface is closely attached to the inner cavity wall surface of the middle housing 5. The outer diameter of the right segment circular ring is the same as the outer wall surface diameter of the middle housing 5.

[0040] A plurality of slits 601 are provided in the slit heat exchanger 6. The plurality of slits 601 are evenly arranged along the circumference of the cylindrical cavity. The slits extend outward from the inner wall surface of the cylindrical cavity in the diameter direction. The slit 601 is in the shape of a long strip with arcs at both ends. The radius of the inner arc of the slit 601 is the same as the radius of the cylindrical cavity of the hot-end heat exchanger 6. The slit 601 extends outward from the inner wall surface in the diameter direction, exceeding the outer diameter of a section of the heat exchanger with a smaller outer diameter, approaching but less than the outer diameter of the bottom surface of the frustum cavity in the expansion cylinder 8, aiming to enable the working medium gas to fully exchange heat with the environment in the hot-end heat exchanger 6. The number of the slits 601 is 26 - 30. In the embodiment, the number of the slits 601 is 28. A circular ring notch 602 is further provided on the hot-end heat exchanger (6). The circular ring notch 602 on the hot-end heat exchanger 6 is aligned with the gas pipeline connected to the compressor in the middle housing 5, guiding the working medium gas into the inner cavity of the hot-end heat exchanger 6. The gas can only flow through the slits 601 on the left segment circular ring and the right segment circular ring of the hot-end heat exchanger 6 in sequence and then enter the regenerator cavity 903, which is beneficial to enhancing heat exchange.

[0041] The slit heat exchanger 6 is made of high thermal conductivity copper to fully conduct the heat at the hot end of the expander and reduce the thermal conduction resistance.

[0042] The middle housing 5 and the slit heat exchanger 6 are welded and connected at the weld joint 202. The expansion cylinder 8 and the slit heat exchanger 6 are welded and connected at the weld joint 203. A sealing ring 301 is provided between the middle housing 5 and the inner liner 3, aiming to seal the back pressure cavity 12 and the main housing cavity 13 to prevent gas leakage.

[0043] A protruding cylindrical cylinder is provided in the middle of the expansion cylinder 8, and a plurality of side ventilation holes 904 are provided at the end of the cylindrical cylinder.

[0044] The inner liner 3 is arranged in the middle housing 5. The side surface of the inner liner 3 is connected to the middle housing 5, and the end surface of the inner liner 3 is connected to the small disk of the slit heat exchanger 6.

[0045] The cold head 11 is sleeved on the end of the cylindrical cylinder of the expansion cylinder 8. The expansion cylinder 8 and the cold head 11 are welded and connected at the weld joint 111.

[0046] The motion unit includes the expander leaf spring 7, the displacer rod 4, the regenerator housing 9, and the regenerator head 10.

[0047] The edge of the expander leaf spring 7 is fixedly connected to the inner bushing 3 by bolts, and the expander leaf spring 7, the inner bushing 3 and the middle housing 5 are fixedly connected by bolts 401.

[0048] The ejector rod 4 is arranged inside the inner bushing 3, one end is connected to the expander leaf spring 7, and the other end is connected to one end of the regenerator housing 9. Threaded holes are opened on both end faces of the ejector rod 4, and the left end face is fixedly connected to the expander leaf spring 7 by bolts 402.

[0049] One end of the regenerator housing 9 is arranged inside the inner bushing 3, and the other end is arranged inside the cylindrical cylinder. A segmented cylindrical through hole is opened at the center position of the left end face of the regenerator housing 9. Bolts 403 are inserted to fixedly connect the ejector rod 4 and the regenerator housing 9, and the head of the bolt 403 is placed in the stepped through hole of the regenerator housing 9 for a tight fit. The regenerator housing 9 and the expansion cylinder 8 form a "seal-gap-seal" sealing form in the expander regenerator section. The sealing is achieved by coating a wear-resistant material 801 on the outer wall surface of the regenerator housing 9. This sealing method can effectively reduce the axial heat conduction loss of the regenerator.

[0050] The regenerator head 10 is arranged at the other end of the regenerator housing. The regenerator head 10 seals the opening of the right cavity of the regenerator housing 9 by threads. An annular gap space is formed between the inner wall of the cold head 11 and the outer wall of the regenerator housing 9. The working medium gas enters the expansion cavity 112 through the side vent holes 904 of the regenerator housing 9 to produce cold.

[0051] As Figure 3 、 4 shown in Figures 7, 8, 9, a plurality of vent holes 901 are evenly distributed on the bottom end face of the regenerator housing 9. The purpose is to balance the pressures of the main cavity 13 and the sub-cavity 15 of the housing, make the pressures of the two chambers the same, and avoid uneven pressure distribution everywhere. A plurality of arc-shaped notches 902 are opened on the regenerator housing 9 located in the frustum-shaped cavity of the expansion cylinder 8. The left end face of the notch 902 is flush with the right end face of the slit heat exchanger 6. The purpose is to connect the main cavity 13 of the housing and the regenerator cavity 903 while ensuring that the regenerator housing in the two different cavities does not separate and becomes a continuous structure. Considering that the regenerator housing 9 makes a harmonic motion in the axial direction, it is necessary to ensure that the main cavity 13 of the housing and the regenerator cavity 903 are always in a connected state and the working medium gas flows unobstructed. Therefore, the arc-shaped notch 902 cannot be blocked by the housing. When the regenerator housing 9 moves to the equilibrium position, there is a certain distance between the right end face of the circular ring structure of the inner bushing 3 sandwiched between the slit heat exchanger 6 and the regenerator housing 9 and the left end face of the arc-shaped notch 902, and there is a certain distance between the right end face and the right wall surface of the frustum-shaped inner cavity of the expansion cylinder 8. The two distances are the same, and this distance is equal to the amplitude of the expander leaf spring 7. Let the amplitude of the expander leaf spring 7 be X, and both distances be L, then X is equal to L.

[0052] In this example, the amplitude X of the expander leaf spring 7 is 2 mm, and the clearance length L is 2 mm. When the regenerator housing 9 moves to the top dead center, the right end face of the arc-shaped notch 902 is flush with the right wall surface of the inner cavity of the conical part of the expansion cylinder 8. When the regenerator housing 9 moves to the bottom dead center, the left end face of the arc-shaped notch 902 is flush with the right end face of the annular structure of the inner lining sleeve 3.

[0053] As Figure 1 and Figure 2 shown, the shock absorber unit includes a shock absorber leaf spring 101, a shock absorber outer gasket 102, a shock absorber inner gasket 103, a wear-resistant layer 104, a shock absorber block 105, and a central fixing bolt 106.

[0054] One end of the central fixing bolt 106 is connected to the bottom housing 2, and the other end is connected to the shock absorber block 105.

[0055] Two shock absorber leaf springs 101 are arranged in parallel on the central fixing bolt 106 and are located inside the shock absorber block 105.

[0056] Both sides of the central fixing bolt 106 have external threads. One end is fixed to the shock absorber leaf spring 101 by adding a nut, and at the same time, the position of the shock absorber inner gasket 103 sandwiched between the two leaf springs is fixed. The other end is inserted into the threaded hole on the left end face of the bottom housing 2 to be connected to the bottom housing 2.

[0057] The shock absorber leaf spring 101 and the shock absorber block 105 have aligned through holes, and the two are connected together by inserting bolts. At the same time, the position of the shock absorber outer gasket 102 sandwiched between the shock absorber leaf spring 101 and the shock absorber block 105 is fixed.

[0058] The principle of the shock absorber is to utilize the anti-resonance characteristics of a two-degree-of-freedom system to transfer the energy of the main system vibration to the additional mass of the shock absorber to reduce or suppress the vibration of the original structure. It has the advantages of simple structure, no additional power consumption, and good effect on suppressing fundamental frequency vibration.

[0059] Working process of the split Stirling expander:

[0060] The pressure wave generator in the compressor generates an alternating pulsating pressure wave through the reciprocating linear motion of the compression piston. Along with the generation of the pulsating pressure wave, a pulsating gas mass flow rate wave is formed inside the cold finger. When a suitable phase difference is achieved between the pulsating pressure wave and the mass flow rate wave, refrigerating capacity can be obtained. During the cycle, the pressure fluctuation in the back pressure chamber 12 is relatively small, basically the ambient pressure. The aerodynamic forces on the displacer rod 4 and the regenerator housing 9 come from the pressure difference formed between the compressor and the cold finger. The expander leaf spring 7 provides radial support and axial elastic force for the displacer rod 4 and the regenerator housing 9 to ensure their ideal amplitudes.

[0061] After the working medium gas is compressed in the compressor, it enters the expander through the connecting pipe, releases the heat generated during the compression process to the environment through the slit heat exchanger 6, and then the gas flows into the regenerator housing 9 through the arc-shaped notch 902 to release heat to the regenerator packing. At this time, the temperature and pressure of the working medium gas both decrease, and then it enters the expansion chamber 112 for expansion refrigeration. At this time, the regenerator housing 9 moves to the left to export the cold quantity by using the cold head 11. The gas after expansion flows back into the interior of the regenerator housing 9 to absorb the heat of the packing. At this time, the temperature and pressure of the working medium gas both increase, and finally it flows back to the compressor to continue to be compressed, completing one cycle.

[0062] As Figure 11 , 12 , as shown in Fig. 13, there are clearance seals L1 and L2 between the regenerator housing 9 and the expansion cylinder 8. L1 and L2 have the same length. The difference between the inner diameter of the regenerator housing 9 and the outer diameter of the expansion cylinder 8 is 16 - 40 μm (radius difference 8 - 20 μm). There is a clearance seal L3 between the regenerator housing 9 and the inner lining sleeve 3, with a lower machining accuracy requirement. The difference between the inner and outer diameters is 200 - 400 μm (radius difference 100 - 200 μm). There is a clearance seal L4 between the ejector rod 4 and the inner lining sleeve 3, with an inner and outer diameter difference of 16 - 40 μm (radius difference 8 - 20 μm). The outer surfaces of the ejector rod 4, the regenerator housing 9, and the expansion cylinder 8 need to ensure a cylindricity of 0.01. The inner cylindrical surfaces of the ejector rod 4 and the inner lining sleeve 3 need to ensure a coaxiality of 0.01. The outer cylindrical surfaces of the ejector rod 4 and the regenerator housing 9 need to ensure a coaxiality of 0.01.

[0063] This example is applicable to refrigeration temperatures above 77K (-196°C), and can provide a net refrigerating capacity of more than 2W at the lowest refrigeration temperature.

[0064] Example Two

[0065] The other structures of this example are the same as those of Example One, except that the structure of the regenerator housing 14 in this example is different from that of the regenerator housing 9 in Example One.

[0066] As Figure 10 shown, in this example, there are no vent holes on the bottom end face of the regenerator housing 14. There is a gap between the cylindrical surface of the regenerator housing 14 and the inner wall surface of the inner lining sleeve 3, with a unilateral gap of 0.3 - 0.5 mm. The main cavity 13 of the housing communicates with the sub-cavity 15 of the housing through a gap. During the operation of the expander, the pressures in the main cavity 13 and the sub-cavity 15 of the housing always maintain dynamic balance, which is beneficial to reducing the radial vibration of the regenerator housing 9 and ensuring the stability of the operating conditions of the expander.

[0067] Functions and Effects of the Example

[0068] For the split Stirling expander according to this embodiment, the expander cancels the water-cooled jacket structure externally connected to the expander of the traditional split Stirling refrigerator, and designs a hot-end slit heat exchanger that matches the basic components of the expander to replace it. The gas working medium releases enough heat to the environment through the hot-end heat exchanger. By changing parameters such as the number and width of the slits of the hot-end heat exchanger, the requirements for the heat dissipation of the gas working medium by the expander under different working conditions can be met.

[0069] The expander optimizes the structures of the expander housing, the displacer rod, and the regenerator housing, making the regenerator included in the expansion piston assembly. The structure is simple, convenient for processing and manufacturing, reduces the dead volume, as well as the pumping loss, shuttle loss, and axial heat conduction loss in the structure of the traditional expander, thereby reducing the weight and volume of the entire Stirling device, and improving the refrigeration performance and reliability.

[0070] In addition, the split Stirling expander of this embodiment further includes a shock absorber unit, which is used to utilize the anti-resonance characteristics of the two-degree-of-freedom system to transfer the energy of the main system vibration to the additional mass of the shock absorber to reduce or suppress the vibration of the original structure. It has the advantages of simple structure, no additional power consumption, and good effect of suppressing the fundamental frequency vibration.

[0071] Furthermore, there are no ventilation holes on the bottom end face of the regenerator housing, and there is a gap between the cylindrical surface of the regenerator housing and the inner wall surface of the inner lining sleeve. During the operation of the expander, the pressures in the main cavity and the divided cavity of the housing always maintain dynamic balance, which is beneficial to reducing the radial vibration of the regenerator housing and ensuring the stability of the operating conditions of the expander.

[0072] The above embodiments are preferred cases of the present invention and are not used to limit the protection scope of the present invention.

Claims

1. A split Stirling expander, characterized in that, Comprising: A housing unit and a motion unit, wherein, the housing unit includes a bottom housing, a middle housing, a slit heat exchanger, an expansion cylinder and a lining sleeve connected in sequence, the slit heat exchanger is in the shape of a flange plate, having a connected large ring plate and a small ring plate, a protruding cylindrical cylinder is provided in the middle of the expansion cylinder, one end of the bottom housing is connected to one end of the middle housing, the other end of the middle housing is connected to one end of the large ring plate of the slit heat exchanger, the other end of the large ring plate of the slit heat exchanger is connected to one end of the expansion cylinder, the lining sleeve is arranged in the middle housing, and the side surface and the end surface of the lining sleeve are respectively connected to the middle housing and the small ring plate, the motion unit includes an expander leaf spring, an ejector rod and a regenerator housing, the expander leaf spring is fixedly connected to the lining sleeve, one end of the regenerator housing is arranged in the lining sleeve, and the other end is arranged in the cylindrical cylinder, the ejector rod is arranged in the lining sleeve, one end is connected to the expander leaf spring, and the other end is connected to one end of the regenerator housing, a cylindrical cavity and a plurality of slits are provided in the middle of the slit heat exchanger, the plurality of slits are uniformly arranged along the circumference of the cylindrical cavity, the slits extend radially outward from the inner wall surface of the cylindrical cavity, the slits extend radially outward from the inner wall surface of the cylindrical cavity to between the large ring plate and the small ring plate, wherein, a circular notch is provided on the small ring plate.

2. The split Stirling expander according to claim 1, wherein: Among them, The number of the slits is 20 - 35.

3. The split Stirling expander according to claim 1, wherein: Among them, A plurality of through holes are provided along the circumference on the regenerator housing.

4. The split Stirling expander according to claim 3, wherein: Among them, The through holes are arc-shaped, and the number is 3 - 6. When the operating condition of the expander is in a balanced state, the through holes are in the bottom inner cavity of the expansion cylinder, the distance between the upper end surface of the through holes and the bottom end surface of the expansion cylinder is the same as the movement amplitude of the regenerator housing, and the distance between the lower end surface of the through holes and the top end surface of the lining sleeve is the same as the movement amplitude of the regenerator housing.

5. The split Stirling expander according to claim 1, wherein: Among them, The ejector rod and the regenerator housing are fixedly connected by bolts.

6. The split Stirling expander according to claim 1, wherein: Among them, A sealing ring is further provided between the middle housing and the lining sleeve.

7. The split Stirling expander according to claim 1, wherein: Among them, A layer of wear-resistant material for sealing is provided on the outer wall surface of the regenerator housing to reduce the axial heat conduction loss of the regenerator.

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