Rotary split stirling cryocooler with coaxial rotor configuration

Abstract

This invention provides a rotary split-type Stirling refrigerator with a coaxial rotor configuration, comprising: a compressor including a housing, a drive shaft, a first cam, and a second cam; an axially sliding first piston and a second piston are mounted within the housing; the first piston is slidably connected to a first track groove of the first cam; the second piston is slidably connected to a second track groove of the second cam; the first cam and the second cam are respectively connected to opposite ends of the drive shaft; the first track groove is arranged around the drive shaft, and the axial position of the first track groove changes periodically and continuously with the circumferential angle; the first cam and the second cam are symmetrically arranged; and a piston expander, with both the first and second hot chambers communicating with the cold chamber of the piston expander. This not only eliminates the lateral force of the piston and allows the volumes of the first and second hot chambers to be adjusted synchronously, making the center of gravity of the compressor almost constant, but also cancels out the axial vibration of the compressor, significantly reducing vibration and abnormal noise.

Description

Technical Field

[0001] This invention relates to the field of Stirling refrigerator technology, and particularly to a rotating split-type Stirling refrigerator with a coaxial rotor configuration. Background Technology

[0002] Stirling refrigerators, due to their excellent cooling performance, are often used for cooling high-performance infrared focal plane array detectors, gamma-ray detectors, or other low-temperature electronic devices. A Stirling refrigerator consists of a compressor, an expander, and a motor controller. Through the periodic pressurization of the compressor, the cold end of the expander expands and absorbs heat, creating a low-temperature zone and thus generating cooling capacity. Stirling refrigerators can be classified into rotary and linear types based on their motion drive mechanism.

[0003] In rotary structures, the compressor and expander components are typically vertically distributed and integrated. A crank-connecting rod mechanism simultaneously drives the compression and expansion pistons, allowing for a 90° phase difference between their cycles to achieve optimal refrigeration efficiency. However, the large lateral force of the crank-connecting rod can lead to significant vibration and piston wear, affecting the reliability of the device.

[0004] Linear compressor designs typically use a linear motor to drive the compressor piston in a reciprocating motion, thus avoiding lateral forces on the piston and reducing vibration in the Stirling refrigerator. However, because a linear motor drives the piston, the piston's reciprocating motion is slow, resulting in significant energy loss and low refrigeration efficiency. Summary of the Invention

[0005] This invention provides a rotating split-type Stirling refrigerator with a coaxial rotor configuration, which provides a Stirling refrigerator with low vibration and high cooling efficiency, overcoming the shortcomings of current Stirling refrigerators.

[0006] This invention provides a rotating split-type Stirling refrigerator with a coaxial rotor configuration, comprising: A compressor includes a housing, a drive shaft, a first cam, and a second cam, wherein a first piston and a second piston capable of sliding along the extension direction of the drive shaft are mounted within the housing; One end of the first piston forms a first thermal chamber with the housing, and the other end is slidably connected to the first track groove of the first cam. One end of the second piston forms a second hot chamber with the housing, and the other end is slidably connected to the second track groove of the second cam; The first cam and the second cam are respectively connected to opposite ends of the drive shaft. The first track groove is arranged around the drive shaft, and the axial position of the first track groove changes periodically and continuously with the circumferential angle. The first cam and the second cam are arranged symmetrically with respect to a first plane, and the first plane is perpendicular to the extension direction of the drive shaft. A piston expander, wherein both the first hot chamber and the second hot chamber are connected to the cold chamber of the piston expander; When the drive shaft rotates around the pivot, the first piston and the second piston reciprocate synchronously along the axis of the housing, so that the volume of the first hot chamber and the second hot chamber changes periodically.

[0007] In one embodiment, the first cam has a cylindrical structure, and the first track groove is disposed on the inner wall of the first cam; The first piston has a first push rod inserted into the first cam at the end away from the first hot chamber. The first push rod is connected to a radially extending guide portion, which extends into the first track groove and slides in cooperation with the first cam. In one embodiment, the guide portion is connected to a rolling bearing, the outer ring of which extends into the first track groove and fits against the groove wall of the first track groove, so that when the first cam rotates, the rolling bearing moves linearly along the axis of the drive shaft under the limitation of the first track groove.

[0008] In one embodiment, a first guide sleeve is further installed inside the housing, and a first rotation limiting groove is provided on the first guide sleeve, which extends linearly along the extension direction of the drive shaft. The first push rod is also connected to a first sliding part, which is inserted into the first limiting groove and slides in cooperation with the first limiting groove. In one embodiment, the axial position of the first track groove changes periodically along the circumferential angle, and includes at least one complete change cycle within a circumferential 360° range.

[0009] In one embodiment, the projection of the first track groove onto the circumferential unfolded surface along the drive shaft extends in a sinusoidal curve.

[0010] In one embodiment, the housing is symmetrically arranged relative to the first plane, and the first piston and the second piston are symmetrically distributed relative to the first plane.

[0011] In one embodiment, a rotor is also included; The housing includes a first cylindrical section and a second cylindrical section that are separately disposed. One end of the rotor is inserted into the first cylindrical section and detachably connected to the first cylindrical section. The other end of the rotor is inserted into the second cylindrical section and detachably connected to the second cylindrical section. The drive shaft is installed inside the rotor and extends out of the rotor at both ends. The first boss is installed inside the first cylindrical section and detachably connected to one end of the drive shaft. The second boss is installed inside the second cylindrical section and detachably connected to the other end of the drive shaft.

[0012] In one embodiment, the piston expander includes a constant-cooling shell, a cold chamber formed within the constant-cooling shell, a pushing piston installed in the constant-cooling shell, the pushing piston being slidable along the axial direction of the constant-cooling shell, one end of the pushing piston extending into the cold chamber, and the other end of the pushing piston extending out of the constant-cooling shell and connected to an elastic element. The piston can move periodically along the axial direction of the constant-cooling shell under the combined action of the periodic gas pressure fluctuations at the end of its extension into the cold chamber and the elastic element.

[0013] In one embodiment, the cold chamber includes a pneumatic section, a regenerating section, and a cold end connected in sequence. One end of the push piston extends into the pneumatic section, which is connected to the first hot chamber and the second hot chamber. A regenerator is installed in the regenerating section, and a cold plate is installed in the cold end.

[0014] Compared with existing technologies, the advantages of this invention are that by driving the piston movement of the compressor through a cam structure, lateral forces on the piston are avoided, reducing vibration. Furthermore, the piston can be forced to reciprocate under the action of the track grooves, resulting in more sensitive piston movement mode switching and higher cooling efficiency compared to the electromagnetic drive of a linear motor. Additionally, by symmetrically arranging the first and second pistons and driving their reciprocating movement through symmetrically arranged first and second track grooves, the center of gravity of the compressor remains almost unchanged during piston extension and retraction, thus canceling axial vibration, increasing the compression ratio, and enhancing cooling efficiency. Attached Figure Description

[0015] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0016] Figure 1 This is a cross-sectional view of the rotary split-type Stirling refrigerator in an embodiment of the present invention; Figure 2 This is a cross-sectional view of the compressor in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the first cam in an embodiment of the present invention; Figure 4 This is a three-dimensional structural diagram of the first push rod in an embodiment of the present invention; Figure 5 This is a three-dimensional structural schematic diagram of the first guide sleeve in an embodiment of the present invention; Figure 6 This is a cross-sectional view of the first cylindrical portion in an embodiment of the present invention; Figure 7 This is a three-dimensional structural diagram of the end cap in an embodiment of the present invention; Figure 8 This is a cross-sectional structural schematic diagram of the piston expander in an embodiment of the present invention; Figure 9 This is a three-dimensional structural schematic diagram of the pushing piston in an embodiment of the present invention; Figure 10 This is a schematic diagram illustrating the overall structure of the Stirling refrigerator and the changes in the volume of each chamber and the total volume in an embodiment of the present invention.

[0017] Figure label: 100. Compressor; 110. Shell; 111. First cylindrical section; 112. Second cylindrical section; 113. End cap; 114. Stator; 120. Drive shaft; 130. First cam; 131. First track groove; 132. Cam cylinder; 133. Cam limiting sleeve; 140. Second cam; 141. Second track groove; 150. First piston; 151. First push rod; 152. Guide part; 153. Rolling bearing; 154. First sliding part; 160. Second piston; 161. Second push rod; 162. Second sliding part; 170. First guide sleeve; 171. First rotation limit groove; 180. Second guide sleeve; 181. Second rotation limit groove; 190. Rotor; 191. Support frame; 192. Support bearing; 200. Piston expander; 210. Refrigeration shell; 211. Cylinder liner; 212. Cold finger; 220. Push piston; 221. Tail end limiting part; 222. Sliding rod part; 223. Vent part; 224. Vent hole; 230. Elastic components; 241. Pneumatic section; 242. Regenerating section; 243. Cold end; 250. Regenerator; 260. Cold storage unit; 270. Protective casing. Detailed Implementation

[0018] The invention will now be further described with reference to the accompanying drawings.

[0019] See Figure 1 as well as Figure 2 As shown, the present invention provides a rotary split-type Stirling refrigerator with a coaxial rotor 190 configuration, which includes a compressor 100 and a piston expander 200 arranged separately. The piston expander 200 and the compression chamber of the compressor 100 are connected so that the piston in the piston expander 200 can move back and forth along the expansion chamber under periodically fluctuating gas pressure to complete the cooling of the cold chamber.

[0020] The compressor 100 includes a housing 110, a drive shaft 120, a first cam 130 and a second cam 140. A first piston 150 and a second piston 160 that can slide along the extension direction of the drive shaft 120 are installed in the housing 110. One end of the first piston 150 forms a first hot chamber with the housing 110, and the other end is slidably connected to the first track groove 131 of the first cam 130; One end of the second piston 160 forms a second hot chamber with the housing 110, and the other end is slidably connected to the second track groove 141 of the second cam 140; The first cam 130 and the second cam 140 are respectively connected to the opposite ends of the drive shaft 120. The first track groove 131 is arranged around the drive shaft 120, and the axial position of the first track groove 131 changes periodically and continuously with the circumferential angle. The first cam 130 and the second cam 140 are arranged symmetrically with respect to a first plane, and the first plane is perpendicular to the extension direction of the drive shaft 120. The piston expander 200 has its first hot chamber and second hot chamber both connected to the cold chamber of the piston expander 200. When the drive shaft 120 rotates around the pivot, the first piston 150 and the second piston 160 reciprocate synchronously along the axis of the housing 110, so that the volume of the first hot chamber and the second hot chamber changes periodically.

[0021] When the drive shaft 120 rotates, the first cam 130 and the second cam 140 connected to both ends of the drive shaft 120 rotate synchronously. The first track groove 131 on the first cam 130 is arranged around the drive shaft 120, and the axial position of the first track groove 131 changes periodically and continuously with the circumferential angle. That is to say, when the first cam 130 rotates, the circumferential angle adjustment of the first track groove 131 will cause the first piston 150, whose circumferential position remains unchanged, to contact other areas of the first track groove 131, and move synchronously along the axial direction as the axial position of the contact area changes. Its basic principle is similar to that of a cylindrical cam structure. The first piston 150 can be moved linearly back and forth in the axial direction by the first cam 130 rotating around the axis, thereby achieving periodic compression of the first hot chamber. Correspondingly, the rotation of the second cam 140 will also drive the second piston 160 to move linearly back and forth in the axial direction, thereby achieving periodic compression of the second hot chamber.

[0022] Compared to the linear motion of the piston driven by a crank-connecting rod mechanism, the first piston 150 and the first cam 130 in this application form a cam-slider structure. The first piston 150 no longer bears lateral force, which not only reduces piston wear caused by lateral force but also reduces piston vibration. Furthermore, because the first track groove 131 and the second track groove 141 are symmetrically arranged relative to the first plane, and the first plane is perpendicular to the extension direction of the drive shaft 120, the first piston 150 and the second piston 160 are arranged opposite each other, with the same reciprocating stroke and aligned cycles. This ensures that the speeds of the first piston 150 and the second piston 160 are always equal in magnitude but opposite in direction, and their axial vibrations can cancel each other out, further reducing the vibration of the Stirling refrigerator.

[0023] See Figure 2 , Figure 3 as well as Figure 4 As shown, in some implementations, the first cam 130 has a cylindrical structure, and the first track groove 131 is disposed on the inner wall of the first cam 130. The first piston 150 is provided with a first push rod 151 inserted into the first cam 130 at one end away from the first hot chamber. The first push rod 151 is connected to a radially extending guide portion 152, which extends into the first track groove 131 and slides in cooperation with the first cam 130.

[0024] By setting the first track groove 131 on the inner wall of the cylindrical structure of the first cam 130, the cylindrical structure of the first cam 130 can surround the end of the first push rod 151 of the first piston 150. Compared with the cylindrical cam setting the guide groove on the outer cylindrical surface of the cylindrical cam, the first track groove 131 set inside the first cam 130 in this application can reduce the radial dimension of the device, which is beneficial to the miniaturization of the Stirling refrigerator.

[0025] See Figure 2 , Figure 3 as well as Figure 4 As shown, in some implementations, the first cam 130 includes a cam cylinder portion 132 and a cam limiting sleeve 133 installed within the cam cylinder portion 132, with the cam cylinder portion 132 and the cam limiting sleeve 133 forming a first trajectory groove 131. Correspondingly, the second cam 140 also includes a cam cylinder portion 132 and a cam limiting sleeve 133, with the cam cylinder portion 132 and the cam limiting sleeve 133 forming a second trajectory groove 141.

[0026] When the first cam 130 rotates, the guide portion 152 moves linearly in the axial direction as the first cam 130 rotates, thereby pushing the first piston 150 to move linearly along the first hot chamber.

[0027] Correspondingly, the second cam 140 is symmetrically arranged with the first cam 130 and is also a cylindrical structure. The second track groove 141 is correspondingly arranged inside the second cam 140. The end of the second piston 160 away from the second hot chamber is provided with a second push rod 161 inserted into the second cam 140. The second push rod 161 is connected to a radially extending guide part 152. The guide part 152 is inserted into the second track groove 141 and slides in cooperation with the second cam 140.

[0028] When the first cam 130 drives the first piston 150 to reciprocate, the volume of the first hot chamber changes periodically. Simultaneously, the second piston 160 reciprocates along the second hot chamber, causing its volume to change periodically as well. Because the first and second bosses are symmetrically arranged, the volume changes of the first and second hot chambers are synchronized. That is, when the volume of the first hot chamber increases, the volume of the second hot chamber increases synchronously, and vice versa. This increases the compression rate of the compressor 100 per unit time, enhancing the cooling effect of the Stirling refrigerator.

[0029] See Figures 2-4As shown, in some implementations, the guide portion 152 is connected to a rolling bearing 153. The outer ring of the rolling bearing 153 extends into the first track groove 131 and fits against the groove wall of the first track groove 131, so that when the first cam 130 rotates, the rolling bearing 153 moves linearly along the axis of the drive shaft 120 under the constraint of the first track groove 131. Thus, when the first cam 130 rotates, the rotation of the first track groove 131 drives the rolling bearing 153 to move, thereby realizing the axial linear movement of the first piston 150.

[0030] Compared to directly sliding the guide portion 152 with the first track groove 131, by connecting the rolling bearing 153 at the guide portion 152, the frictional loss at the guide portion 152 can be reduced, and the first piston 150 can move more smoothly along the axis.

[0031] Understandably, a rolling bearing 153 is also connected to the guide portion 152 of the second cam 140. The rolling bearing 153 extends into the second track groove 141 so that when the second cam 140 rotates, the rolling bearing 153 moves linearly along the axis of the drive shaft 120 under the constraint of the second track groove 141. This makes the linear movement of the second piston 160 smoother.

[0032] See Figure 2 , Figure 4 as well as Figure 5 As shown, in some implementations, a first guide sleeve 170 is also installed inside the housing 110. The first guide sleeve 170 has a first rotation-limiting groove 171, which extends linearly along the extension direction of the drive shaft 120. The first push rod 151 is also connected to a first sliding part 154, which is inserted into the guide groove and slides in cooperation with the first rotation-limiting groove 171. That is, by providing the first guide sleeve 170 with the first rotation-limiting groove 171 and the first sliding part 154 inserted into the first rotation-limiting groove 171, the movement mode of the first push rod 151 is to slide along the extension direction of the first rotation-limiting groove 171, preventing the first push rod 151 from rotating. It can be understood that, in order to achieve the effect of limiting the rotation of the first push rod 151, the cross-section of the first rotation-limiting groove 171 is non-circular, and the sliding part is inserted into the first rotation-limiting groove 171 corresponding to the cross-section of the first rotation-limiting groove 171.

[0033] Correspondingly, a second guide sleeve 180 is also installed inside the housing 110. The second guide sleeve 180 is provided with a second rotation limiting groove 181, which extends linearly along the extension direction of the drive shaft 120. The second push rod 161 is connected to a second sliding part 162, which is inserted into the second guide groove and slides in cooperation with the second rotation limiting groove 181. In other words, the movement direction of the second sliding part 162 is restricted by the second rotation limiting groove 181, thereby preventing the second push rod 161 from rotating during linear movement and ensuring that the second piston 160 reciprocates linearly along the axial direction.

[0034] In order to enable the first piston 150 and the second piston 160 to move smoothly, a sliding bearing is connected at the connection between the first sliding part 154 and the first limiting groove 171. The sliding bearing is slidably installed in the first limiting groove 171, that is, the sliding of the first sliding part 154 and the first limiting groove 171 occurs at the sliding bearing. The surface of the sliding bearing is smooth, which greatly reduces the friction during the sliding process and reduces the resistance of the first piston 150 during the sliding process.

[0035] Correspondingly, a sliding bearing is also connected at the connection between the second sliding part 162 and the second limiting groove 181 to reduce the friction between the second piston 160 and the second limiting groove 181.

[0036] See Figure 1 , Figure 2 as well as Figure 3 As shown, in some implementations, the axial position of the first track groove 131 changes periodically along the circumferential angle, and includes at least one complete change cycle within a circumferential 360° range.

[0037] In other words, when the first cam 130 rotates one revolution, the first piston 150 will contact the first track groove 131 located at different circumferential angles, thereby moving axially under the constraint of the first track groove 131. The axial movement period of the first piston 150 corresponds to the axial position change period of the first track groove 131.

[0038] In some implementations, the axial position of the first track groove 131 varies along a sinusoidal curve in the circumferential direction. The curve equation of the axial position of the first track groove 131 is as follows: Where y is the circumferential angle when the first cam 130 rotates. The axial position of the first track groove 131, A, Both k and k are constants. In other words, when the first cam 130 rotates one revolution in the circumferential direction, the axial position of the first piston 150 fluctuates within the range of -A to A. Correspondingly, the second cam 140 is symmetrically arranged with respect to the first cam 130. When the axial position of the first track groove 131 changes sinusoidally along the circumferential angle, the axial position of the second track groove 141 also changes sinusoidally along the circumferential angle, and the changes in both occur synchronously. That is, when the first piston 150 moves away from the first cam 130, the second piston 160 will synchronously move away from the second cam 140, and the moving speed of the second piston 160 is equal to the moving speed of the first piston 150.

[0039] Understandably, in some implementations, adjustments can be made. This causes the axial movement period of the first piston 150 to be adjusted accordingly. The axial movement period T of the first piston 150 is... That is, when the circumferential angle x of the first cam 130 increases by 1 / 2... At that time, the first piston 150 moves linearly back and forth for one cycle. To ensure the continuity of the first trajectory groove 131, it is preferable to... It is a positive integer.

[0040] In some implementations, the axial position of the first trajectory groove 131 changes continuously along the circumferential angle in a wave-shaped curve, with a change period of 2π.

[0041] See Figure 1 as well as Figure 2 As shown, in some implementations, the housing 110 is symmetrically arranged relative to the first plane, and the first piston 150 and the second piston 160 are symmetrically distributed relative to the first plane. That is, the main body of the compressor 100 is symmetrically arranged along the first plane, so that the center of gravity of the compressor 100 is located at the first plane. Since the first track groove 131 and the second track groove 141 are also symmetrical along the first plane, the first piston 150 and the second piston 160 can always be symmetrical about the first plane, thereby avoiding the shift of the center of gravity and significantly reducing the noise of the compressor 100 during operation.

[0042] See Figure 1 as well as Figure 2 As shown, in some implementations, the rotary split Stirling refrigerator also includes a rotor 190; The housing 110 includes a first cylindrical portion 111 and a second cylindrical portion 112 that are separately disposed. One end of the rotor 190 is inserted into the first cylindrical portion 111 and detachably connected to the first cylindrical portion 111. The other end of the rotor 190 is inserted into the second cylindrical portion 112 and detachably connected to the second cylindrical portion 112. The drive shaft 120 is installed inside the rotor 190 and extends out of the rotor 190 at both ends. The first boss is installed inside the first cylindrical portion 111 and detachably connected to one end of the drive shaft 120. The second boss is installed inside the second cylindrical portion 112 and detachably connected to the other end of the drive shaft 120.

[0043] In other words, by setting the housing 110 as a split structure with a first cylindrical portion 111 and a second cylindrical portion 112, and by detachably connecting the first cylindrical portion 111 and the second cylindrical portion 112 to the rotor 190, the difficulty of installing the rotor 190 into the housing 110 is reduced. During installation, the first piston 150 can be first installed into the first cylindrical portion 111, then the end of the first piston 150 can be connected to the first cam 130, and finally the first cam 130 can be connected to the rotor 190, so that the rotor 190 can be inserted into and connected to the first cylindrical portion 111. This allows the rotor 190 to drive the first cam 130 to rotate, thereby achieving linear motion drive of the first piston 150.

[0044] Correspondingly, when connecting the rotor 190 to the second cylinder 112, the second piston 160 can be installed into the second cylinder 112 first, then the end of the second piston 160 can be connected to the second cam 140, and finally the second cam 140 can be connected to the rotor 190, so that the rotor 190 is inserted into the second cylinder 112 and connected to the second cylinder 112.

[0045] See Figure 1 , Figure 2 , Figure 6 as well as Figure 7 As shown, in some implementations, end caps 113 are connected to the ends of the first cylindrical section 111 and the second cylindrical section 112, respectively. The end caps 113 seal the end of the compressor 100 away from the rotor 190. A vent pipe is connected to the end caps 113, and the other end of the vent pipe is connected to the piston expander 200. In addition, to improve the stability of the housing 110, a stator 114 is also connected to the outside of the first cylindrical section 111 and the second cylindrical section 112. The stator 114 and the rotor 190 form a drive motor. By controlling the change of the current flowing into the stator 114, a changing magnetic field is formed at the stator 114, thereby driving the rotor 190, which is equipped with a permanent magnet, to rotate, thereby driving the drive shaft 120.

[0046] See Figure 1 , Figure 2as well as Figure 6 As shown, in some implementations, a support frame 191 is also provided inside the housing 110, with one support frame 191 corresponding to each end of the rotor 190, and the rotor 190 is connected to the support frame 191 through a support bearing 192 so that the rotor 190 can rotate smoothly relative to the housing 110.

[0047] See Figure 1 , Figure 8 as well as Figure 9 As shown, in some implementations, the piston expander 200 includes a constant-cooling shell 210, a cold chamber formed inside the constant-cooling shell 210, a push piston 220 installed in the constant-cooling shell 210, the push piston 220 being slidable along the axial direction of the constant-cooling shell 210, one end of the push piston 220 extending into the cold chamber, and the other end of the push piston 220 extending out of the constant-cooling shell 210 and connected to the elastic member 230; The push piston 220 can move periodically along the axial direction of the constant-cool shell 210 under the combined action of the periodic gas pressure fluctuations at the end of its extension into the cold chamber and the elastic element 230.

[0048] The constant-cooling shell 210 includes a cylinder liner 211 and a cooling finger 212. The push piston 220 is slidably connected to the cylinder liner 211, and one end extends into the cooling finger 212. Because this application has two pistons, a first piston 150 and a second piston 160, and when the first piston 150 compresses the first hot chamber, the second piston 160 can correspondingly compress the second hot chamber, thus increasing the compression ratio and compression efficiency of the compressor 100 compared to a single hot chamber. This allows the gas in the compressor 100 to be pressurized and introduced into the cold chamber of the piston expander 200, so that the piston expander 200 can achieve cooling of the cold platform 260 under periodically fluctuating gas pressure changes.

[0049] In some implementations, the elastic element 230 is a spring to cope with the pressure changes in the cold chamber and drive the push piston 220 to reciprocate linearly under pressure changes.

[0050] Because the piston in compressor 100 can reciprocate linearly, the volume of the total chamber changes synchronously with the movement of the first piston 150 and the second piston 160, thus causing a corresponding change in the air pressure in the cold chamber. One end of the push piston 220 is connected to the air pressure environment of the cold chamber, while the other end is connected to an elastic element 230 and extends into the back pressure chamber where the air pressure is stable. Fluctuations in the air pressure in the cold chamber will drive the push piston 220 to move, achieving forced movement and thus changing the volume of the cold chamber. This ensures that the movement cycle of the first piston 150 and the movement cycle of the push piston 220 have approximately a 90° phase difference, achieving a better cooling effect.

[0051] The constant-temperature shell 210 has low thermal conductivity, thus ensuring good low-temperature retention. A cooling stage 260 is installed on the constant-temperature shell 210, and the cooling stage 260 is connected to the cooling chamber. The cooling stage 260 is made of heat-conducting components. Workpieces requiring cooling are typically placed on the cooling stage 260 so that heat can be absorbed from the workpiece through the cooling stage 260 during cooling of the cooling chamber, thus completing the cooling process.

[0052] See Figure 1 , Figure 8 as well as Figure 9 As shown, in some implementations, the cold chamber includes a pneumatic section 241, a regenerating section 242, and a cold end 243 connected in sequence. The end of the push piston 220 away from the back pressure chamber extends into the pneumatic section 241. The pneumatic section 241 is connected to the first hot chamber and the second hot chamber. A regenerator 250 is installed at the regenerating section 242, and a cold stage 260 is installed at the cold end 243.

[0053] The regenerator 250, also known as a heat exchanger, is typically filled with a metal mesh or metal balls. When the working fluid flows through the regenerator 250, it exchanges heat with the packing material, adjusting the temperature of the working fluid to match the temperature of the packing material. The working fluid in the cold chamber can flow along the regenerator section 242 to the cold end 243 or the pneumatic section 241, creating a temperature gradient when the refrigeration unit is operating stably. One side of the pneumatic section 241 is at room temperature, while the other side of the cold end 243 is at a low temperature.

[0054] In this application, a piston 220 is also provided outside the constant-cooling shell 210, comprising a tail-end limiting part 221, a sliding rod part 222, and a venting part 223 connected in sequence. The cross-sectional areas of the tail-end limiting part 221 and the venting part 223 are both larger than the cross-sectional area of ​​the sliding rod part 222. The sliding rod part 222 is connected to the sliding hole of the constant-cooling shell 210 and can slide along the sliding hole of the constant-cooling shell 210. A protective shell 270 is also installed outside the constant-cooling shell 210. The protective shell 270 surrounds the constant cooling shell 210 to form a back pressure cavity. The end of the tail limiting part 221 of the push piston 220 extends into the back pressure cavity and is connected to the elastic member 230 in the back pressure cavity. The elastic member 230 is sleeved on the slide rod part 222 of the push piston 220 extending out of the cold cavity. One end of the elastic member 230 abuts against the constant cooling shell 210, and the other end abuts against the tail limiting part 221. The venting part 223 extends into the pneumatic section 241.

[0055] Combination Figure 8 as well as Figure 9As shown, the push piston 220 mainly bears the air pressure F1 from the cold chamber, the air pressure F2 from the back pressure chamber, and the elastic force F3 from the elastic element 230 in the horizontal direction. F1 = P1 * (A1 - A2), where P1 is the air pressure in the cold chamber, A1 is the exposed area at the right end of the vent 223, and A2 is the exposed area at the left end of the vent 223. Referring to the attached diagram, A1 - A2 = A3, where A3 is the cross-sectional area at the right end of the slide rod 222, and F1 faces left. F2 = P2 * (B1 - B2), where P2 is the air pressure in the back pressure chamber, B1 is the exposed area at the left end of the tail-end limiting part 221, and B2 is the exposed area at the right end of the tail-end limiting part 221. B1 - B2 = B3, where B3 is the cross-sectional area at the left end of the slide rod 222, and B3 = A3, and F2 faces right. Under the action of the elastic element 230, the push piston 220 can be balanced by the pressure difference between the left and right sides, so F3=F1-F2=(P1-P2)*A3 can be obtained. The elastic force of the elastic element 230 is F3=k*l, where k is the elastic coefficient of the elastic element 230 and l is the extension and contraction of the elastic element 230. It can be seen that the push piston 220 can be forced to move back and forth under the pressure fluctuation.

[0056] See Figure 8 as well as Figure 9 As shown, an axially extending vent hole 224 is provided on the push piston 220, and the gas at the pneumatic section 241 can pass through the vent hole 224 to enter the regenerating section 242 to realize the flow of the working fluid.

[0057] Specifically, in combination Figure 1 , Figure 2 , Figure 8 as well as Figure 10 As shown, the refrigeration cycle of a Stirling refrigerator is as follows: Section cd: Both the first piston 150 and the second piston 160 move away from the rotor 190, corresponding to the transition of the first and second hot chambers from their maximum volume to an intermediate volume. During this time, the pushing piston 220 inside the expander continuously compresses the cold chamber under pressure fluctuations, causing the cold chamber's volume to shrink synchronously. This results in a decrease in the total volume of the cold chamber + first hot chamber + second hot chamber, leading to an isothermal compression and heat release process. The hot chambers are larger, and the cold chambers are smaller; this process is primarily driven by the compression of the hot chambers. In this stage, the working fluid is compressed, the pressure rises, and the heat of compression is carried away by the cooling medium, keeping the temperature largely constant. To quickly remove heat, a heat dissipation mechanism can be connected to the compressor 100 to maintain the first and second hot chambers at ambient temperature.

[0058] In stage da: the volumes of the first and second hot chambers further decrease from their intermediate volumes to their minimum volumes, causing the gas pressure to rise. Under the influence of the pressure difference, piston 220 moves in the opposite direction, increasing the volume of the cold chamber. This results in a relatively small change in the overall volume of the cold chamber + first hot chamber + second hot chamber, with the hot chambers decreasing in size and the cold chambers increasing in size. The refrigerant moves towards the cold chambers and releases heat to the packing material in the regenerator 250, undergoing an isochoric heat release process. During this stage, the refrigerant flows through the regenerator 250, releasing heat to the packing material, causing the temperature of the refrigerant to decrease.

[0059] Section ab: At this point, the first piston 150 and the second piston 160 move in opposite directions, increasing the volume of both the first and second hot chambers. Correspondingly, the volume of the cold chamber also increases with the movement of the pushing piston 220. The overall volume of the first hot chamber + second hot chamber + cold chamber increases, and the entire system undergoes an isothermal expansion and heat absorption process. The hot chambers are relatively small, while the cold chambers are relatively large; this process is primarily driven by the expansion chambers. During this stage, the working fluid expands, its pressure decreases, and it absorbs heat from the cold stage 260, thereby cooling the cold stage 260 and completing the refrigeration process.

[0060] Section bc: The first piston 150 and the second piston 160 continue to move toward the rotor 190, and the volume of the first hot chamber and the second hot chamber further increases. The pushing piston 220 changes its direction of movement under the action of external air pressure, and the volume of the refrigeration chamber decreases. The overall volume change in the first hot chamber and the second hot chamber is small. Because the first hot chamber and the second hot chamber become larger and the cold chamber becomes smaller, the overall refrigerant moves toward the first hot chamber and the second hot chamber. The refrigerant absorbs heat from the packing of the regenerator 250 and undergoes an isochoric heat absorption process. The temperature of the refrigerant rises back to near the temperature of the hot chamber.

[0061] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A rotating, split-type Stirling refrigerator with a coaxial rotor configuration, characterized in that, It includes: A compressor includes a housing, a drive shaft, a first cam, and a second cam, wherein a first piston and a second piston capable of sliding along the extension direction of the drive shaft are mounted within the housing; One end of the first piston forms a first thermal chamber with the housing, and the other end is slidably connected to the first track groove of the first cam. One end of the second piston forms a second hot chamber with the housing, and the other end is slidably connected to the second track groove of the second cam; The first cam and the second cam are respectively connected to opposite ends of the drive shaft. The first track groove is arranged around the drive shaft, and the axial position of the first track groove changes periodically and continuously with the circumferential angle. The first cam and the second cam are arranged symmetrically with respect to a first plane, and the first plane is perpendicular to the extension direction of the drive shaft. A piston expander, wherein both the first hot chamber and the second hot chamber are connected to the cold chamber of the piston expander; When the drive shaft rotates around the pivot, the first piston and the second piston reciprocate synchronously along the axis of the housing, so that the volume of the first hot chamber and the second hot chamber changes periodically.

2. The rotary split-type Stirling refrigerator according to claim 1, characterized in that, The first cam has a cylindrical structure, and the first track groove is disposed on the inner wall of the first cam; The first piston has a first push rod inserted into the first cam at the end away from the first hot chamber. The first push rod is connected to a radially extending guide portion, which extends into the first track groove and slides in cooperation with the first cam.

3. The rotary split-type Stirling refrigerator according to claim 2, characterized in that, The guide portion is connected to a rolling bearing, the outer ring of which extends into the first track groove and fits against the groove wall of the first track groove, so that when the first cam rotates, the rolling bearing moves linearly along the axis of the drive shaft under the constraint of the first track groove.

4. The rotary split-type Stirling refrigerator according to claim 2, characterized in that, A first guide sleeve is also installed inside the housing. The first guide sleeve is provided with a first rotation limiting groove, which extends linearly along the extension direction of the drive shaft. The first push rod is also connected to a first sliding part, which is inserted into the first limiting groove and slides in cooperation with the first limiting groove.

5. The rotary split-type Stirling refrigerator according to any one of claims 1-4, characterized in that, The axial position of the first track groove changes periodically along the circumferential angle, and includes at least one complete change cycle within a circumferential 360° range.

6. The rotary split-type Stirling refrigerator according to claim 5, characterized in that, The projection of the first track groove onto the circumferential unfolded surface along the drive shaft extends in a sinusoidal curve.

7. The rotary split-type Stirling refrigerator according to any one of claims 1-4, characterized in that, The housing is symmetrically arranged relative to the first plane, and the first piston and the second piston are symmetrically distributed relative to the first plane.

8. The rotary split-type Stirling refrigerator according to any one of claims 1-4, characterized in that, It also includes the rotor; The housing includes a first cylindrical section and a second cylindrical section that are separately disposed. One end of the rotor is inserted into the first cylindrical section and detachably connected to the first cylindrical section. The other end of the rotor is inserted into the second cylindrical section and detachably connected to the second cylindrical section. The drive shaft is installed inside the rotor and extends out of the rotor at both ends. The first boss is installed inside the first cylindrical section and detachably connected to one end of the drive shaft. The second boss is installed inside the second cylindrical section and detachably connected to the other end of the drive shaft.

9. The rotary split-type Stirling refrigerator according to any one of claims 1-4, characterized in that, The piston expander includes a constant-cooling shell, a cold chamber formed inside the constant-cooling shell, a pushing piston installed in the constant-cooling shell, the pushing piston being able to slide along the axial direction of the constant-cooling shell, one end of the pushing piston extending into the cold chamber, and the other end of the pushing piston extending out of the constant-cooling shell and connected to an elastic element. The piston can move periodically along the axial direction of the constant-cooling shell under the combined action of the periodic gas pressure fluctuations at the end of its extension into the cold chamber and the elastic element.

10. The rotary split-type Stirling refrigerator according to claim 9, characterized in that, The cold chamber includes a pneumatic section, a regenerating section, and a cold end connected in sequence. One end of the push piston extends into the pneumatic section, which is connected to the first hot chamber and the second hot chamber. A regenerator is installed in the regenerating section, and a cold platform is installed in the cold end.

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