Stepping type Stirling refrigerator
By applying the principle of stepper motor in the Stirling refrigerator, the contactless drive piston movement is achieved using electromagnetic pole sets and coil windings, which solves the problem of high noise in the Stirling refrigerator, and achieves a lower noise and more efficient refrigeration effect, providing possibilities for more usage scenarios.
Patent Information
- Application Number
- CN202510267773.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2025-04-25
AI Technical Summary
The existing Stirling refrigerators are noisy when working, and it is difficult to effectively reduce them.
Using the principle of stepper motor, the electromagnetic pole group is combined with multiple coil windings. By changing the energization sequence of the coil windings, the movement of the first piston and the second piston in the piston cavity is realized without contact, thereby completing the four cycle processes of isothermal compression, isovolume heat release, isothermal expansion, and isovolume heat absorption of the Stirling refrigerator.
It effectively reduces the noise generated by the Stirling refrigerator during operation, improves the user experience, and provides the possibility for the Stirling refrigeration system to be applied in more usage scenarios, while reducing parameter sensitivity and reducing components, which is conducive to improving the reliability of the refrigeration system.
Smart Images
Figure CN119879423A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of refrigerators, and in particular relates to a step-type Stirling refrigerator. Background Art
[0002] A Stirling refrigerator is a mechanical refrigeration device driven by electricity. Its working principle is based on the Stirling cycle, also known as the constant volume regenerative cycle. The Stirling refrigerator achieves the refrigeration effect by cyclically compressing and expanding the gas. Due to its compact structure, wide operating temperature range, fast startup, high efficiency, and easy operation, it is widely used in low temperature fields such as aerospace, missile guidance, remote sensing and telemetry.
[0003] However, existing Stirling coolers all have the defect of making loud noise during operation.
[0004] Therefore, how to reduce the noise generated by the Stirling refrigerator during operation is a technical problem that technicians in this field have always wanted to solve but have not been able to solve. Summary of the invention
[0005] The purpose of the present invention is to provide a step-type Stirling refrigerator, which can effectively reduce the noise generated by the Stirling refrigerator during operation.
[0006] The step-type Stirling refrigerator comprises a shell, a mounting cavity formed in the shell, a first piston and a second piston located in the mounting cavity, an electromagnetic pole group is fixedly installed in the mounting cavity, the electromagnetic pole group has a plurality of coil windings arranged side by side along the axial direction of the shell, a piston cavity distributed along the axial direction is opened in the center of the electromagnetic pole group, the first piston and the second piston are both arranged in the piston cavity, and the first piston and the second piston can be driven to move in the piston cavity in a specified order and direction by controlling the power-on sequence of the coil windings.
[0007] Based on the above structure, the present invention applies the principle of stepper motor to the linear drive structure of the Stirling refrigerator, wherein the magnetic fields of the first piston and the second piston are radially distributed, and an electromagnetic pole group formed by multiple coil windings is arranged at a fixed interval on the outer periphery of the piston, and the magnetic field generated by the energization of the electromagnetic pole group is also radially distributed. Therefore, by changing the energization sequence of each coil winding, the first piston and the second piston can be driven contactlessly to move in a prescribed sequence, thereby realizing the four cycle processes of isothermal compression, isochoric heat release, isothermal expansion, and isochoric heat absorption of the Stirling refrigerator, thereby effectively reducing the noise generated by the Stirling refrigerator during operation, improving user experience, and providing the possibility for the Stirling refrigeration system to be applied to more usage scenarios.
[0008] Furthermore, the shell includes a compression section, a heat storage section and an expansion section connected in sequence, and an insulating ring is provided between the compression section and the heat storage section, and between the heat storage section and the expansion section. A heat conduction plate is connected to the end of the compression section away from the heat storage section, and a heat exchange element is connected to the end of the expansion section away from the heat storage section. The heat exchange element is used to be connected to a cold circulation device.
[0009] The above design not only makes it convenient to fix the electromagnetic pole group in the shell, but also because of the four cycle processes of the Stirling refrigerator, namely isothermal compression, isochoric heat release, isothermal expansion, and isochoric heat absorption, the shell corresponding to each cycle process can be insulated by setting an insulating ring to ensure the normal operation of the Stirling refrigerator.
[0010] Furthermore, a heat dissipation component is provided on the outer wall of the compression section and the heat conducting plate.
[0011] The heat dissipation component can be used to dissipate the heat from the hot end of the Stirling refrigerator, and the cold circulation device can be used to exchange heat with the cold end of the Stirling refrigerator, thereby achieving refrigeration for the required usage scenario.
[0012] Furthermore, the thermal insulation ring extends between two adjacent coil windings in the electromagnetic pole group.
[0013] By adopting the above structure, the coil windings corresponding to each cycle process of the refrigerator can be insulated by providing an insulating ring, thereby reducing the complexity of the structure and the implementation cost.
[0014] Furthermore, a heat-conducting layer is filled between the electromagnetic pole group and the compression section, and two axial ends of the heat-conducting layer are respectively in contact with the heat-conducting plate and the heat-insulating ring arranged between the compression section and the heat storage section.
[0015] Through the design of the heat-conducting layer, the heat generated by the compression process of the Stirling refrigerator is transferred to the heat-conducting plate, and then the heat is dissipated by the heat dissipation component.
[0016] Furthermore, the electromagnetic pole group also includes a magnetic isolation ring, which is arranged between two adjacent coil windings.
[0017] By setting the magnetic isolation ring, the isolation effect between the energized and non-energized coil windings can be enhanced, so that after the coil windings are energized in the required sequence, the positions of the first piston and the second piston can be accurately controlled, thereby ensuring the control accuracy and use effect of the refrigerator described in the present invention.
[0018] Furthermore, the number of the coil windings is not less than 8, and in an initial state, the position of the first piston is consistent with the position of the leftmost coil winding.
[0019] By using no less than 8 coil windings, it is possible to ensure that the first piston and the second piston are driven to move in the specified order and direction after being energized in the designed sequence, thereby effectively reducing the noise generated by the Stirling refrigerator during operation. At the same time, a contactless drive structure is realized, which can reduce parameter sensitivity, reduce components, and help improve the reliability of the refrigeration system.
[0020] Furthermore, the permanent magnets on the first piston and the second piston repel each other.
[0021] The two mutually exclusive pistons can avoid being sucked together and causing the refrigerator to malfunction.
[0022] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention applies the principle of a stepper motor to the linear drive structure of a Stirling refrigerator, wherein the magnetic field of the piston mover is radially distributed, and a plurality of coils are arranged at a fixed interval on the periphery of the piston, and the magnetic field generated by the coils being energized is also radially distributed. Therefore, by changing the energization sequence of each coil, the internal mover can be driven contactlessly to move in a prescribed sequence, thereby effectively reducing the noise generated by the Stirling refrigerator during operation, improving user experience, and providing the possibility for the Stirling refrigeration system to be applied to more usage scenarios.
[0023] 2. The present invention adopts a contactless driving structure, which can reduce parameter sensitivity, reduce components, and help improve the reliability of the refrigeration system.
[0024] 3. The present invention dissipates heat from the shell through a heat dissipation component and designs a heat storage section to transfer heat, thereby overcoming the defects of the Stirling refrigerator in the prior art such as poor heat exchange performance and poor waste heat recovery effect, reducing energy loss and improving the efficiency of the refrigerator. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a schematic diagram of the relative positions of the first piston, the second piston and the electromagnetic pole group in the initial state of the present invention; Figure 3 It is a schematic diagram of the relative positions of the first piston, the second piston and the electromagnetic pole group under the isothermal compression state of the present invention; Figure 4 It is a schematic diagram of the relative positions of the first piston, the second piston and the electromagnetic pole group under the isochoric heat release state of the present invention; Figure 5 It is a schematic diagram of the relative positions of the first piston, the second piston and the electromagnetic pole group under the isothermal expansion state of the present invention; Figure 6 It is a structural schematic diagram of the shell described in the present invention.
[0026] The names of the components in the figure are: 1. Shell; 1.1. Compression section; 1.2. Heat storage section; 1.3. Expansion section; 1.4. Heat exchange element; 2. Heat conductive layer; 3. First piston; 4. Second piston; 5. Installation cavity; 6. Electromagnetic pole group; 6.1. Coil winding; 6.2. Magnetic isolation ring; 7. Piston cavity; 8. Cold circulation device; 9. Heat conductive plate; 10. Heat dissipation assembly; 11. Insulation ring. DETAILED DESCRIPTION
[0027] The present invention is further described below through specific embodiments in conjunction with the accompanying drawings, but the present invention is not limited thereto. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
[0028] Example 1 like Figure 1-Figure 6 As shown, an embodiment of the present invention provides a step-type Stirling refrigerator, including a housing 1, a first piston 3, a second piston 4, a mounting cavity 5, an electromagnetic pole group 6, a piston cavity 7, a cold circulation device 8, a heat conducting plate 9, and a heat dissipation component 10. The heat conducting plate 9 and the cold circulation device 8 are respectively arranged at the left and right ends of the housing 1, and a mounting cavity 5 is formed in the housing 1 between the heat conducting plate 9 and the cold circulation device 8. The first piston 3, the second piston 4, and the electromagnetic pole group 6 are installed in the mounting cavity 5. The center of the electromagnetic pole group 6 is provided with a piston cavity 7 distributed along its axial direction. The first piston 3 and the second piston 4 are provided with a piston cavity 7 distributed along its axial direction. The two pistons 4 are both arranged in the piston cavity 7. The permanent magnets on the first piston 3 and the second piston 4 repel each other to avoid being attracted together and causing the refrigerator to malfunction. The electromagnetic pole group 6 has a plurality of coil windings 6.1 arranged side by side. Each coil winding 6.1 is circumferentially arranged on the outside of the piston cavity 7. By controlling the power-on sequence of the coil windings 6.1, the first piston 3 and the second piston 4 can be driven to move in the piston cavity 7 in a specified sequence and direction; a heat dissipation component 10 is covered on the left end of the shell 1, and a cold circulation device 8 is connected to the right end of the shell 1.
[0029] This embodiment applies the principle of a stepper motor to the linear drive structure of a Stirling refrigerator, wherein the magnetic fields of the first piston 3 and the second piston 4 are radially distributed, and an electromagnetic pole group 6 formed by a plurality of coil windings 6.1 is arranged at a fixed interval on the outer circumference of the piston, and the magnetic field generated by the electromagnetic pole group 6 when energized is also radially distributed. Therefore, by changing the energization sequence of each coil winding 6.1, the first piston 3 and the second piston 4 can be driven contactlessly to move in a prescribed sequence (for easy distinction, the four pistons are marked as A, B, C, and D in the accompanying drawings, respectively), thereby realizing the four cyclic processes of isothermal compression, isochoric heat release, isothermal expansion, and isochoric heat absorption of the Stirling refrigerator. In this cycle, the cold circulation device 8 on the right side continuously absorbs heat from the gas, and the temperature is reduced, becoming a cold end. Therefore, heat exchange can be performed with the cold end of the Stirling refrigerator through the heat conduction plate 9, thereby realizing the refrigeration of the required usage scenario; while the left side of the shell 1 continuously releases the heat absorbed by the gas, becoming a hot end, and the hot end of the Stirling refrigerator can be dissipated through the heat dissipation component 10. Due to the use of a contactless drive structure, it not only effectively reduces the noise generated by the Stirling refrigerator during operation, improves the user experience, and provides the possibility for the Stirling refrigeration system to be applied to more usage scenarios; it can also reduce parameter sensitivity, reduce components, and help improve the reliability of the refrigeration system.
[0030] from Figure 1 and Figure 6 It can be seen that the shell 1 includes a compression section 1.1, a heat storage section 1.2 and an expansion section 1.3 connected in sequence, and an insulation ring 11 is provided between the compression section 1.1 and the heat storage section 1.2, and between the heat storage section 1.2 and the expansion section 1.3. A heat conducting plate 9 is connected to the end of the compression section 1.1 away from the heat storage section 1.2, and a heat exchange element 1.4 is connected to the end of the expansion section 1.3 away from the heat storage section 1.2. The heat exchange element 1.4 is used to be connected to the cold circulation device 8.
[0031] Through the above design, not only can the electromagnetic pole group be conveniently fixed in the shell, but also because of the four cycle processes of the Stirling refrigerator, namely isothermal compression, isochoric heat release, isothermal expansion, and isochoric heat absorption, the shell corresponding to each cycle process can be insulated by setting an insulating ring to ensure that the Stirling refrigerator can work normally.
[0032] Preferably, a heat dissipation component 10 is provided on the outer wall of the compression section 1.1 and the heat conducting plate 9.
[0033] With the above design, the heat dissipation component 10 can be used to dissipate heat from the entire hot end of the Stirling refrigerator, thereby improving the heat exchange efficiency of the Stirling refrigerator during use.
[0034] Preferably, the thermal insulation ring 11 extends between two adjacent coil windings 6 . 1 in the electromagnetic pole group 6 .
[0035] By adopting the above structure, the coil windings corresponding to each cycle process of the refrigerator can be insulated by providing an insulating ring, thereby reducing the complexity of the structure and the implementation cost.
[0036] Preferably, a heat conducting layer 2 is filled between the electromagnetic pole group 6 and the compression section 1.1, and the two axial ends of the heat conducting layer 2 are respectively in contact with the heat conducting plate 9 and the heat insulating ring provided between the compression section 1.1 and the heat storage section 1.2.
[0037] Through the design of the heat-conducting layer, the heat generated by the compression process of the Stirling refrigerator is transferred to the heat-conducting plate, and then the heat is dissipated by the heat dissipation component.
[0038] See attached Figure 2 In this embodiment, the number of the coil windings 6.1 is 12, which are the parts numbered al from left to right in the figure, and in the initial state, the position of the first piston 3 is consistent with the position of the coil winding 6.1 numbered a on the far left, and the position of the second piston 4 is consistent with the position of the coil winding 6.1 numbered e. At the same time, since the total number of the coil windings 6.1 is 12, the second piston 4 moves to the coil winding 6.1 numbered l at most.
[0039] Of course, it should be noted that the number of coil windings 6.1 is not necessarily 12, and it can be adaptively set according to different control accuracy and power.
[0040] from Figure 2 It can also be seen that the electromagnetic pole group 6 also includes a magnetic isolation ring 6.2, which is arranged between two adjacent coil windings 6.1. By setting the magnetic isolation ring 6.2, the isolation effect between the energized and non-energized coil windings 6.1 can be enhanced, so that the positions of the first piston 3 and the second piston 4 can be accurately controlled after the coil windings 6.1 are energized in the required order, thereby ensuring the control accuracy and use effect of the refrigerator of the present invention. In the specific implementation process, the magnetic isolation ring 6.2 can be made of ferrite materials and other functional materials that have the functions of absorbing, shielding and dispersing magnetic fields.
[0041] The working principle of the present invention is: In the initial state, all coil windings 6.1 are at different points, the position of the first piston 3 is adapted to the position of the leftmost coil winding 6.1 numbered a, and the position of the second piston 4 is adapted to the position of the coil winding 6.1 numbered e. Figure 2 As shown; During the isothermal compression process, the coil winding 6.1 numbered e is continuously energized to keep the second piston 4 stationary, and at the same time, the three groups of coil windings 6.1 numbered ab, bc, and cd are energized in sequence in pairs, that is, the two coil windings 6.1 numbered ab are energized at the same time, the two coil windings 6.1 numbered bc are energized at the same time, and the two coil windings 6.1 numbered cd are energized at the same time, so that the first piston 3 moves to the right to approach the second piston 4 to compress the gas, and when the coil windings 6.1 numbered c and d are energized, the coil windings 6.1 numbered e and f are energized at the same time to improve the compression capacity. In this state, the gas is compressed, the pressure increases, but the temperature remains unchanged, and the gas releases heat to the surrounding environment; during this process, the first piston 3 moves to the coil winding 6.1 numbered c, and the position of the second piston 4 remains unchanged, such as Figure 3 As shown; In the isochoric heat release process, the four groups of coil windings 6.1 numbered dg, eh, gi, and hj are energized in sequence, that is, the four coil windings 6.1 numbered d, e, f, and g are energized first, and then the four coil windings 6.1 numbered e, f, g, and h are energized, and then the four coil windings 6.1 numbered f, g, h, and i are energized, and finally the three coil windings 6.1 numbered h, i, and j are energized, so that the relative position of the first piston 3 and the second piston 4 remains unchanged and moves to the cold end synchronously, the gas releases heat, and its temperature and pressure are reduced; in this process, the first piston 3 moves to the coil winding 6.1 numbered h, and the second piston 4 moves to the coil winding 6.1 numbered j, as shown in FIG. Figure 4 As shown; During the isothermal expansion process, the coil windings 6.1 numbered h and i remain energized, and the coil windings 6.1 with corresponding numbers are energized in sequence in the manner of j and k, k and l, and l. That is, firstly, the two coil windings 6.1 numbered j and k are energized at the same time, then the two coil windings 6.1 numbered k and l are energized at the same time, and finally, the coil winding 6.1 numbered l is energized, and when the coil winding 6.1 numbered l is energized, the coil winding 6.1 numbered i stops energizing, allowing the second piston 4 to move to the left and right sides, i.e., the extreme edge of the cold end, to achieve expansion and heat absorption of the gas; during this process, the position of the first piston 3 remains unchanged, and the second piston 4 moves to the coil winding 6.1 numbered l, as shown in FIG. Figure 5 As shown; In the isochoric endothermic process, the six coil windings 6.1 numbered g, f, e, d, c, and b are energized in sequence to drive the first piston 3 to move to the coil winding 6.1 numbered a. At the same time, the six coil windings 6.1 numbered k, j, i, h, g, and f are energized in sequence, so that the second piston 4 and the first piston 3 keep their relative positions unchanged and move together to the coil winding 6.1 numbered e at the hot end, so that the first piston 3 and the second piston 4 move to the initial position, and the refrigerator returns to the initial state, completing a cycle.
[0042] Example 2 The embodiment of the present invention provides a control method for a step-type Stirling refrigerator as described in Embodiment 1, comprising the following steps: Step 1, isothermal compression process: the coil winding 6.1 numbered e is controlled to be continuously energized to keep the second piston 4 stationary, and the three groups of coil windings 6.1 numbered ab, bc, and cd are controlled to be energized in sequence, that is, the two coil windings 6.1 numbered ab are energized at the same time, the two coil windings 6.1 numbered bc are energized at the same time, and the two coil windings 6.1 numbered cd are energized at the same time, so as to drive the first piston 3 to move to the right side close to the second piston 4 to compress the gas, and when the coil windings 6.1 numbered c and d are energized, the coil windings 6.1 numbered e and f are controlled to be energized at the same time to improve the compression capacity. In this state, the gas is compressed, the pressure increases, but the temperature remains unchanged, and the gas releases heat to the surrounding environment; in this process, the first piston 3 moves to the coil winding 6.1 numbered c, and the position of the second piston 4 remains unchanged, such as Figure 3 As shown; Step 2, isochoric heat release process: control the four groups of coil windings 6.1 numbered dg, eh, gi, and hj to be energized in sequence, that is, first control the four coil windings 6.1 numbered d, e, f, and g to be energized, then control the four coil windings 6.1 numbered e, f, g, and h to be energized, then control the four coil windings 6.1 numbered f, g, h, and i to be energized, and finally control the three coil windings 6.1 numbered h, i, and j to be energized, so that the relative position of the first piston 3 and the second piston 4 remains unchanged and moves to the cold end synchronously, the gas releases heat, and its temperature and pressure are reduced; in this process, the first piston 3 moves to the coil winding 6.1 numbered h, and the second piston 4 moves to the coil winding 6.1 numbered j, as shown in FIG. Figure 4 As shown; Step 3, isothermal expansion process: control the coil windings 6.1 numbered h and i to remain energized, control the coil windings 6.1 numbered j and k, numbered k and l, and numbered l to be energized in sequence, that is, first control the two coil windings 6.1 numbered j and k to be energized at the same time, then control the two coil windings 6.1 numbered k and l to be energized at the same time, and finally control the coil winding 6.1 numbered l to be energized, and when the coil winding 6.1 numbered l is energized, control the coil winding 6.1 numbered i to stop energizing, so that the second piston 4 moves to the left and right sides, i.e., the extreme edge of the cold end, to achieve expansion and heat absorption of the gas; in this process, the position of the first piston 3 remains unchanged, and the second piston 4 moves to the coil winding 6.1 numbered l, as shown in FIG. Figure 5 As shown; Step 4, isochoric heat absorption process: the six coil windings 6.1 numbered g, f, e, d, c, and b are controlled to be energized in sequence to drive the first piston 3 to move to the coil winding 6.1 numbered a, and at the same time, the six coil windings 6.1 numbered k, j, i, h, g, and f are controlled to be energized in sequence so that the second piston 4 and the first piston 3 keep their relative positions unchanged and move together to the coil winding 6.1 numbered e at the hot end, so that the first piston 3 and the second piston 4 move to the initial position, and the refrigerator returns to the initial state; Step 5: Repeat steps 1 to 4 to achieve continuous control of the Stirling refrigerator.
[0043] In summary, the present invention applies the principle of a stepper motor to the linear drive structure of a Stirling refrigerator. The magnetic fields of the first piston 3 and the second piston 4 are radially distributed, and an electromagnetic pole group 6 formed by a plurality of coil windings 6.1 is arranged at a fixed interval on the outer periphery of the piston. The magnetic field generated by the electromagnetic pole group 6 when it is energized is also radially distributed. Therefore, by changing the energization sequence of each coil winding 6.1, the first piston 3 and the second piston 4 can be driven contactlessly to move in a prescribed sequence, thereby realizing four cycles of isothermal compression, isochoric heat release, isothermal expansion, and isochoric heat absorption of the Stirling refrigerator. In this cycle, the cold cycle device 8 on the right side continuously absorbs heat from the gas, and the temperature is reduced to become a cold end, thereby realizing refrigeration of the required usage scenario; while the left side continuously releases the heat absorbed by the gas to become a hot end, and the hot end of the Stirling refrigerator can be dissipated through the heat dissipation component 10. Due to the use of a contactless drive structure, not only the noise generated by the Stirling refrigerator during operation is effectively reduced, the user experience is improved, and the Stirling refrigeration system is applied to more usage scenarios. It also reduces parameter sensitivity, reduces components, and is conducive to improving the reliability of the refrigeration system.
[0044] The technical solution provided by the present invention is described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.
Claims
1. A step-type Stirling refrigerator, comprising a housing (1), a mounting cavity (5) formed in the housing, a first piston (3) and a second piston (4) located in the mounting cavity (5), characterized in that: An electromagnetic pole group (6) is fixedly installed in the installation cavity (5), and the electromagnetic pole group (6) has a plurality of coil windings (6.1) arranged side by side along the axial direction of the housing (1). A piston cavity (7) distributed along the axial direction is opened at the center of the electromagnetic pole group (6), and the first piston (3) and the second piston (4) are both arranged in the piston cavity (7). By controlling the power-on sequence of the coil windings (6.1), the first piston (3) and the second piston (4) can be driven to move in the piston cavity (7) in a specified sequence and direction.
2. The stepping Stirling refrigerator according to claim 1, characterized in that: The shell (1) comprises a compression section (1.1), a heat storage section (1.2) and an expansion section (1.3) which are connected in sequence; a heat insulation ring (11) is provided between the compression section (1.1) and the heat storage section (1.2), and between the heat storage section (1.2) and the expansion section (1.3); a heat conduction plate (9) is connected to one end of the compression section (1.1) away from the heat storage section (1.2); and a heat exchange element (1.4) is connected to one end of the expansion section (1.3) away from the heat storage section (1.2); the heat exchange element (1.4) is used to be connected to a cold circulation device (8).
3. The stepping Stirling refrigerator according to claim 2, characterized in that: A heat dissipation component (10) is provided on the outer walls of the compression section (1.1) and the heat conducting plate (9).
4. The stepping Stirling refrigerator according to claim 2, characterized in that: The thermal insulation ring (11) extends between two adjacent coil windings (6.1) in the electromagnetic pole group (6).
5. The stepping Stirling refrigerator according to claim 4, characterized in that: A heat-conducting layer (2) is filled between the electromagnetic pole group (6) and the compression section (1.1), and two axial ends of the heat-conducting layer (2) are respectively in contact with the heat-conducting plate (9) and a heat-insulating ring provided between the compression section (1.1) and the heat storage section (1.2).
6. The stepping Stirling refrigerator according to claim 1, characterized in that: The electromagnetic pole group (6) further comprises a magnetic isolation ring (6.2), wherein the magnetic isolation ring (6.2) is arranged between two adjacent coil windings (6.1).
7. The stepping Stirling refrigerator according to any one of claims 1 to 6, characterized in that: The number of the coil windings (6.1) is not less than 8, and in an initial state, the position of the first piston (3) is consistent with the position of the leftmost coil winding (6.1).
8. The stepping Stirling refrigerator according to any one of claims 1 to 6, characterized in that: The permanent magnets on the first piston (3) and the second piston (4) repel each other.