Solid-state refrigeration driver based on recovery of mechanical work of unloading, and refrigeration apparatus

Abstract

A rotary solid-state refrigeration driver based on recovery of mechanical work of unloading, and a solid-state refrigeration apparatus. The rotary solid-state refrigeration driver comprises: a rotary motor (9), a main transmission shaft (2) driven by the rotary motor (9) to rotate, N eccentric transmission mechanisms mounted at different axial positions of the main transmission shaft (2), N pistons (1) respectively driven by the N eccentric transmission mechanisms to move in a reciprocating manner, and N elastocaloric materials (10) periodically loaded and unloaded by means of the reciprocating motion of the N pistons (1), wherein the N eccentric transmission mechanisms have different phase angles, such that the N elastocaloric materials (10) are unloaded in different time periods; and during a process of being unloaded, each elastocaloric material (10) releases its own mechanical work to provide thrust for the rotation of the main transmission shaft (2), N being an integer greater than one.

Description

Solid-state refrigeration drive and refrigeration equipment based on unloaded mechanical work recovery

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202311708973.6 filed on December 13, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present invention belongs to the field of solid-state refrigeration technology, and specifically relates to a rotary solid-state refrigeration driver that realizes unloading mechanical work recovery of ejected materials under rotational motion, and a solid-state refrigeration device including the rotary solid-state refrigeration driver. Background Art

[0004] Space cooling is crucial for maintaining a high quality of life in modern society. This includes using air conditioners to lower indoor temperatures and refrigerators to keep food in a specific space cold. However, facing the challenges of future sustainable development, current gas compression-based refrigerators have exposed numerous problems. First, the refrigerants used in gas compression refrigerators present numerous issues. Globally, large quantities of refrigerants used in gas compression refrigerators (such as chlorine- and bromine-containing refrigerants) are produced and released into the environment. While these refrigerants themselves are non-toxic to living organisms, their evaporation into the atmosphere causes a sharp drop in ozone levels, resulting in irreversible damage to the Earth's atmosphere. The ozone hole exposes the Earth's surface to significant amounts of direct ultraviolet radiation, which not only raises global temperatures and triggers more extreme weather events, but also makes organisms susceptible to adverse effects (such as skin cancer) from excessive ultraviolet radiation. Although new refrigerants have been developed through technological iterations (such as fluorine-containing and ammonia-based refrigerants), which have reduced their environmental impact, these refrigerants are flammable and explosive, posing significant safety risks to public use. Secondly, the energy conversion rate of refrigeration through gas compression is currently low. A large portion of the electricity produced by power plants is not effectively converted into the refrigeration process, resulting in a significant waste of public resources. The current metric for evaluating the energy efficiency of coolers is the energy efficiency ratio (EER) (based on the ratio of output cooling power to input electrical power). For example, the EER of air conditioners currently available on the market is approximately 2.3 to 3.5. If air conditioners with a higher EER (e.g., greater than 6) could be used for cooling, the same cooling effect could be achieved with only half the original electrical energy. However, due to the low entropy change during the gas-liquid phase transition, improving the EER of these chillers has encountered inherent technical bottlenecks. Therefore, the proposal and development of a new generation of environmentally friendly and efficient refrigeration technologies has become an important prerequisite for achieving sustainable development in the future.

[0005] Spring-cage solid-state refrigeration technology is a novel refrigeration technology that utilizes the first-order phase transition of solid materials. This technology uses mechanical deformation to induce a phase transition in the material, resulting in the release and absorption of latent heat, thereby reducing the temperature of the target object. A spring-cage refrigeration cycle generally consists of four steps: loading, holding and heat exchange, and unloading, holding and heat exchange. Since this new technology was proposed by British scientists in 2004, it has attracted widespread attention from researchers worldwide. The primary reason for this is its high energy conversion rate, safety during use, and zero environmental emissions. In the 2014 U.S. Department of Energy's Guide to Future Refrigeration Technology Development, spring-cage solid-state refrigeration technology, which utilizes spring-cage materials, received the highest rating and was assessed as one of the refrigeration technologies with the greatest potential to replace existing gas compression refrigeration. Spring-cage materials are solid materials that exhibit the spring-cage (thermal) effect. The spring-cage effect is one of the thermal effects of solid materials. It is the release or absorption of heat caused by the application of an external stress field. Spring-cage materials, based on the phase transition, exhibit high entropy change, which can significantly improve energy conversion efficiency. There are many materials that have the properties of spring-loaded cards, including shape memory alloys, natural rubber, synthetic polymers, and plastic crystals. Among them, shape memory alloys (such as nickel-titanium alloy, copper-aluminum-manganese alloy, nickel-manganese-copper-cobalt alloy, nickel-iron-gallium alloy, etc.) are widely used in spring-loaded card solid-state refrigeration technology due to their extremely high phase transition entropy and material energy efficiency. For example, the widely used nickel-titanium alloy can generate 0.32 J / cm under adiabatic phase transition. 3 The entropy change of K is much higher than the entropy change of R-32 (hydrofluorocarbon), the most commonly used gas compression refrigerant today (0.035 J / cm 3 K). Due to their inherently high phase transition entropy, shape memory alloys can achieve an energy efficiency ratio (EER) exceeding 30. In recent years, research in spring-loaded solid-state refrigeration has yielded numerous results in the development of prototypes, particularly in terms of cooling performance, achieving a large temperature gradient of 50K and a specific cooling power of 6W / g. However, the actual operating EER of the prototype (around 1) is far lower than the material EER. Issues with energy utilization and conversion are severely hindering the further commercialization of this technology.

[0006] One of the main reasons for the low energy efficiency of the prototype solid-state refrigeration system is that the unloading mechanical work of the card material from deformation to recovery is not effectively utilized. When the material is in a deformed state, it is in a state of stored energy. If the external constraints are removed, the card material will release the internally stored mechanical energy. If this mechanical work can be utilized, the power requirement of the external drive can be greatly reduced, thereby achieving a higher system energy efficiency. Today's card refrigeration prototypes generally use a linear drive structure (hydraulic push rods, linear push rods, etc.). For example, a research team from the University of Michigan designed and developed a refrigeration prototype using a hydraulic push rod as the drive and a nickel-titanium alloy tube compression principle. Using water as the heat exchange medium, they achieved a maximum temperature difference of 20K. Their results were published in the international academic journal Science. A research team from the University of Ljubljana also used a hydraulic push rod as the drive of the prototype, using a sleeve structure to compress the nickel-titanium alloy tube to achieve a spring-cage effect. Their results were published in the international academic journal Nature Energy. Chinese patent CN201810660524.1 (publication number CN108954901A, publication date 2018.12.07) demonstrated a spring-cage refrigeration device that utilizes the compression deformation of nickel-titanium alloy tubes. The heat transfer medium used was water. The axial reciprocating motion of a linear motor was used to compress the nickel-titanium alloy tube to cause compression deformation. An external water pump was used to promote water circulation to convective heat transfer on the nickel-titanium alloy tube. Although linear drive is conceptually feasible, whether using a linear motor or a hydraulic device, when there is no external power supply, the pressure head will be locked due to mechanical structure limitations. During the actual unloading process, the drive still needs to input electrical energy to retract the pressure head, which will increase the power consumption of the drive. If the pressure head is not a moving part, the mechanical energy released by the material unloading will not be able to be transferred to another stage and drive the next loading. In contrast, mechanical energy can be easily transferred through rotation. During the unloading process, the linear movement of the material can be used to drive the rotation of the shaft in the tangential direction to maintain the rotation of the shaft; and the rotating shaft can continue to drive the next stage of compression. In addition, due to fewer mechanisms and components, the rotary drive system has higher mechanical efficiency (the ratio of electrical energy input power to mechanical output power). An efficient rotary drive system has a mechanical efficiency of 90%, which can greatly reduce the waste of electricity during its own energy conversion. Although the rotary drive system has great application potential in elastic refrigeration, so far, the existing literature and patents have not provided a clear technical route and structural design of the drive system.

[0007] Summary of the Invention

[0008] In order to solve at least one of the above problems, the present disclosure provides a rotary solid-state refrigeration drive based on unloading mechanical work recovery and a solid-state refrigeration device including the rotary solid-state refrigeration drive.

[0009] According to a first aspect of the present disclosure, a rotary solid-state refrigeration drive based on unloading mechanical work recovery is provided. The rotary solid-state refrigeration drive comprises: a rotary motor, a main transmission shaft driven to rotate by the rotary motor, N eccentric transmission mechanisms installed at different axial positions of the main transmission shaft and driven by the main transmission shaft, N pistons driven to reciprocate by the N eccentric transmission mechanisms, and N spring-loaded materials periodically loaded and unloaded by the reciprocating motion of the N pistons, wherein N is an integer greater than 1; the N eccentric transmission mechanisms have different phase angles relative to the main transmission shaft, so that the N spring-loaded materials are unloaded in different time periods; and each spring-loaded material provides thrust for the rotation of the main transmission shaft by releasing its own mechanical work during the unloading process.

[0010] Optionally, along the axial direction of the main transmission shaft, the phase angle difference between any two adjacent eccentric transmission mechanisms among the N eccentric transmission mechanisms is 360 / N degrees.

[0011] Optionally, the eccentric transmission mechanism cooperates with the main transmission shaft and the piston to form an eccentric connecting rod mechanism, an eccentric cam mechanism, an eccentric bearing mechanism or a crank connecting rod mechanism.

[0012] Optionally, at each of the different axial positions of the main transmission shaft: the cross-section of the main transmission shaft is circular and the center of the circle does not coincide with the rotation axis of the main transmission shaft; and the eccentric transmission mechanism includes a connecting rod part and a pin, the end of the connecting rod part away from the piston includes an annular portion, the annular portion is sleeved on the outer circumferential surface of the main transmission shaft and can slide circumferentially relative to the outer circumferential surface of the main transmission shaft, and the other end of the connecting rod part is hinged to the end of the piston away from the spring-loaded material through the pin.

[0013] Optionally, the connecting rod portion includes an upper connecting rod portion and a lower connecting rod portion, the annular portion is composed of the lower portion of the upper connecting rod portion and the lower connecting rod portion, and the upper connecting rod portion and the lower connecting rod portion are connected together by screws.

[0014] Optionally, the rotary solid-state refrigeration driver further comprises: a linear bearing, which is sleeved outside the corresponding piston and is used to limit the direction of the reciprocating motion of the piston and reduce radial friction.

[0015] Optionally, the rotary solid-state refrigeration driver further includes: a first external rack supporting the corresponding piston and the spring-loaded material, with both ends of each spring-loaded material being fixed between the corresponding piston and the first external rack by direct contact, threaded connection, welding or bonding.

[0016] Optionally, the rotary solid-state refrigeration driver further comprises: an upper shell portion and a lower shell portion, which are respectively used to carry the piston and the main transmission shaft.

[0017] Optionally, the rotary motor is selected from: a servo motor, a stepper motor, a torque motor, a switched reluctance motor, and a brushless DC motor.

[0018] Optionally, the rotary solid-state refrigeration drive further includes a speed reducer, and the speed reducer is used to increase the torque of the rotary motor.

[0019] Optionally, the rotary motor drives the reducer and further drives the main transmission shaft to rotate.

[0020] Optionally, the rotary solid-state refrigeration drive further includes a second external rack for fixing the reducer and the eccentric transmission mechanism.

[0021] Optionally, the geometric shape of the spring-clip material is selected from the group consisting of: cylinder, cube, cuboid, circular tube, and rectangular tube.

[0022] Optionally, the spring card material is selected from: shape memory alloy, natural rubber, synthetic polymer, and plastic crystal.

[0023] Optionally, the spring card material is selected from: nickel-titanium alloy, copper-aluminum-manganese alloy, nickel-manganese-titanium alloy, nickel-titanium-cobalt alloy, nickel-titanium-copper-cobalt alloy, and nickel-iron-gallium alloy.

[0024] Optionally, the deformation mode of the spring-stuck material during the loading-unloading process is uniaxial linear deformation, wherein the uniaxial linear deformation includes linear compression and linear tension.

[0025] According to a second aspect of the present disclosure, a solid-state refrigeration device is provided, which includes a rotary solid-state refrigeration drive based on unloading mechanical work recovery according to the first aspect of the present disclosure, and also includes a heat exchange structure, which is used to exchange heat with the spring card material to transfer the heat and cold generated by the spring card material.

[0026] Compared with the prior art, the rotary solid-state refrigeration drive and solid-state refrigeration device disclosed in the present invention have the following advantages:

[0027] 1. Loading by rotation: Compared with the existing hydraulic or linear motor drive, the number of mechanical transmission devices is greatly reduced, thereby reducing mechanical energy and electrical energy loss.

[0028] 2. Realizes the recovery of unloading mechanical work: The present invention adopts a multi-cylinder structure including multiple eccentric transmission mechanisms and multiple pistons, which can recover the unloading mechanical work of one ejection material and reuse it for loading another ejection material, realizing energy recovery and reducing energy consumption.

[0029] 3. The temperature drop of solid refrigerant is large and adjustable: by adjusting the eccentric distance, the maximum single temperature drop of the card material can be 30 degrees.

[0030] 4. Continuous output of cooling capacity: Compared with traditional spring-loaded materials that need to wait for heat dissipation before using cooling capacity, the present disclosure adopts a multi-cylinder design, and the intermittent cooling of multiple spring-loaded materials can be superimposed into continuous cooling, greatly improving efficiency and cooling power.

[0031] 5. Miniaturization and commercialization: Compared with existing hydraulic or linear motor drives, the overall weight and volume are greatly reduced, and safety and portability are improved.

[0032] 6. High frequency operation: The maximum operating frequency can reach 5Hz, which improves the cooling power. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is a schematic diagram illustrating the principle of unloading mechanical work recovery according to the present disclosure;

[0034] 2 is a perspective view showing a portion of a rotary solid-state refrigeration drive according to an exemplary embodiment of the present disclosure;

[0035] 3 is a front view schematic diagram illustrating the structure and installation process of a portion of a rotary solid-state refrigeration drive according to an exemplary embodiment of the present disclosure;

[0036] 4 is a front schematic diagram showing a portion of a rotary solid-state refrigeration drive according to an exemplary embodiment of the present disclosure;

[0037] 5 is a perspective view showing a portion of a rotary solid-state refrigeration drive according to an exemplary embodiment of the present disclosure;

[0038] FIG. 6 is a graph illustrating changes in torque on a main transmission shaft with respect to a rotation angle according to an exemplary embodiment of the present disclosure and a comparative example.

[0039] Description of reference numerals:

[0040] 1 Piston 2 Main drive shaft 3 Connecting rod

[0041] 3a Upper part of connecting rod 3b Lower part of connecting rod 4 Pin

[0042] 5a Upper part of the housing 5b Lower part of the housing 6 Linear bearing

[0043] 7a Second external carriage 7b First external carriage 8 Speed ​​reducer

[0044] 9 Rotating motor 10 Card material 0 Rotating axis DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the form of unloading mechanical work recovery provided by the present disclosure and the unloading work recovery driver structure applying the principle thereof are described in detail below with reference to the accompanying drawings.

[0046] The terms used in this disclosure are only used to describe specific embodiments and are not intended to limit the disclosure. As used in this disclosure, the term "and / or" includes any and all combinations of one or more related enumerated items. As used in this disclosure, the singular forms "a" and "the" are also intended to include plural forms, unless the context clearly indicates otherwise. As used in this disclosure, the terms "comprising" and "made of" specify the presence of the features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof.

[0047] In the description of the present disclosure, it should be noted that the orientations or positional relationships indicated by the terms "top", "bottom", "up", "down", "left", "right", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the products are usually placed when in use. They are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present disclosure.

[0048] Unless otherwise defined, all terms (including technical and scientific terms) used in this disclosure have the same meanings as those commonly understood by those skilled in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and will not be interpreted as having an idealized or overly formal meaning unless expressly defined in this disclosure.

[0049] As shown in Figure 1, it shows the principle of unloading mechanical work recovery according to the present disclosure. Based on the principle of object deformation, when an object is deformed (stretching, compression, torsion, bending, etc.), it will store elastic deformation mechanical energy. As the deformation ends, the object will output the stored mechanical energy to the outside world. The same is true for the spring card material. Generally speaking, the material used for spring card refrigeration has superelasticity (or pseudo-elasticity), which means that it can undergo large elastic deformation and can restore to its original state without residual strain. Based on this feature, the present disclosure adopts an eccentric transmission mechanism to drive the spring card material to deform, and uses the elastic deformation mechanical energy stored in the spring card material itself to reversely drive the drive shaft of the eccentric mechanism to rotate; at the same time, the spring card material itself will undergo a phase change when subjected to external deformation, releasing or absorbing heat, so that cooling can be performed.

[0050] For simplicity, FIG1 illustrates an eccentric transmission mechanism using an eccentric wheel. When the distal end of the eccentric wheel rotates below the spring-loaded material, it compresses the spring-loaded material, causing it to compress and deform while releasing heat. As the eccentric wheel continues to rotate, after passing the highest point of the distal end, the spring-loaded material enters an unloading process, releasing mechanical energy from elastic deformation and absorbing heat from the surrounding environment. The mechanical energy released by the spring-loaded material can be transferred to the eccentric wheel, thereby helping to drive the eccentric wheel. The inventors also discovered that because the transmission shaft is connected to the motor, the gear structure of the motor itself is self-locking, making it impossible to instantly change speed (i.e., it cannot maintain rotation through inertia). If only a single-cylinder design is used, that is, the device only has one spring-loaded material, the mechanical work instantly transferred to the transmission shaft during unloading cannot be stored and transferred to the next loading time period of the same spring-loaded material. Therefore, the present disclosure adopts a multi-cylinder mechanism design (at least two cylinders). By designing the phase angle of the eccentric position so that one material is loaded while the other is unloaded, the torque on the transmission shaft is reduced due to the simultaneous action of the two materials. That is, the sum of the torques required to drive two materials simultaneously is smaller than the sum of the torques required to drive the two materials separately. This is because unloading work recovery occurs. Based on the above principle, the unloading work recovery ratio of the driver can be roughly calculated using the following formula:

[0051] Where W1 refers to the mechanical work required for a single card material to be loaded and deformed without unloading work recovery; n refers to the number of actuator cylinders (i.e., how many materials are in the actuator); W inIt refers to the total mechanical work (measured value) required to realize the driving process under actual working conditions when using the rotary solid-state refrigeration driver disclosed in this disclosure; W2 refers to the unloaded mechanical work contained in a single material under working conditions. Generally speaking, for materials with a constant elastic modulus coefficient such as springs, W1 is equal to W2. In actual working conditions, since there is a two-phase change process during the phase transition of shape memory alloys, their Young's modulus is constantly changing, which will lead to the occurrence of hysteresis. Part of the unloaded mechanical work will be converted into hysteresis heat and thus lost. Therefore, for the analysis of shape memory alloy systems, W1 is greater than W2.

[0052] Based on the above principles, the exemplary embodiments of the present disclosure provide a rotary solid-state refrigeration drive (hereinafter referred to as the rotary solid-state refrigeration drive) that recovers mechanical work from unloading stuck materials during rotational motion. As shown in Figures 2 to 5 , the rotary solid-state refrigeration drive comprises: a rotary motor 9, a main drive shaft 2, two eccentric transmission mechanisms, two pistons 1, and two stuck materials 10.

[0053] The rotary motor 9 is used to drive the main transmission shaft 2 in rotation. Two eccentric transmission mechanisms are installed at different axial positions on the main transmission shaft 2. The function of the eccentric transmission mechanism is to convert the rotational motion of the main transmission shaft 2 into the linear reciprocating motion of the piston 1. The two spring-loaded materials 10 are periodically loaded and unloaded by the reciprocating motion of the two pistons 1. The phase angles of the two eccentric transmission mechanisms relative to the main transmission shaft 2 (rotation axis O) differ by 180 degrees, so that the time periods during which the two spring-loaded materials 10 are unloaded (or loaded) are staggered. In other words, when one spring-loaded material 10 is loaded, the other spring-loaded material 10 is unloaded. During the unloading process, each spring-loaded material 10 will generate a downward thrust on one of the pistons 1. This thrust will push the piston 1 downward, thereby driving the eccentric transmission mechanism downward at the same time. The transmitted thrust will act tangentially on the main transmission shaft 2, providing thrust for its rotation. Since the two spring-locking materials 10 do not provide thrust to the main transmission shaft 2 at the same time, the thrust does not hinder the rotation of the main transmission shaft 2 , but promotes the rotation of the main transmission shaft 2 and reduces the input work of the rotary motor 9 .

[0054] Specifically, as shown in Figure 2, the main transmission shaft 2 can rotate around the rotation axis O, and the cross-section of the portion of the main transmission shaft 2 where the eccentric transmission mechanism is installed is circular, and the center of the circle does not coincide with the rotation axis O. In other words, the portion of the main transmission shaft 2 where the eccentric transmission mechanism is installed is an eccentric circular structure relative to the rotation axis O of the main transmission shaft 2, that is, the main transmission shaft 2 has a (partial) eccentric shaft structure. There is an angular deviation of 180 degrees in the radial direction between the two eccentric circular portions, that is, the phase angles of the two eccentric circular portions differ by 180 degrees. In addition, the eccentricity of each eccentric circular portion can be set to 1.5 mm, that is, the radial distance between the centers of the two eccentric circular portions is 3 mm.

[0055] As shown in Figure 2, each eccentric transmission mechanism includes a connecting rod portion 3 and a pin 4. The connecting rod portion 3 comprises an upper connecting rod portion 3a and a lower connecting rod portion 3b, which are connected together by screws. The lower end of the upper connecting rod portion 3a and the lower connecting rod portion 3b together form a circular ring. The inner diameter of this circular ring matches the outer diameter of the eccentric structure, allowing the circular ring to be mounted on the outer circumference of the eccentric portion of the main transmission shaft 2 and slide (rotate) circumferentially relative to this outer circumference. The other end of the connecting rod portion 3, namely the upper end of the upper connecting rod portion 3a, is hinged to the lower end of the piston 1 via the pin 4, thereby restricting the piston 1 from moving forward or backward or left and right. Furthermore, because the circular ring of the connecting rod portion 3 is mounted on the eccentric portion with an eccentricity of 1.5 mm, when the main transmission shaft 2 rotates, the connecting rod portion 3 can swing around the pin 4 relative to the piston 1. At the same time, the upper end of the connecting rod portion 3, through the pin 4, drives the piston 1 in a reciprocating motion of approximately 3 mm.

[0056] 3 and 5 , the rotary solid-state refrigeration drive of the exemplary embodiment of the present disclosure may further include two linear bearings 6. Each linear bearing 6 is sleeved outside the corresponding piston 1 to provide constraints for the piston 1 and reduce friction loss when the piston 1 moves up and down.

[0057] As shown in Figure 5, the rotary solid-state refrigeration drive of the exemplary embodiment of the present disclosure may also include two first external racks 7b. The first external rack 7b is a support structure for supporting the corresponding piston 1 and the spring-loaded material 10. The first external rack 7b can also be used to fix the corresponding spring-loaded material 10. The two ends of the spring-loaded material 10 are fixed between the corresponding piston 1 and the first external rack 7b in a direct contact, threaded connection, welding or bonding manner. The first external rack 7b can be installed on the linear bearing 6, and may include a plurality of screws fixed to the top surface of the linear bearing 6 and a top cover fixed to the screws by nuts. The position of the top cover can be adjusted by each nut, and a receiving blind hole or screw hole for receiving the end of the spring-loaded material 10 may be provided on the bottom surface of the top cover and the top surface of the piston 1.

[0058] As shown in FIG4 , the rotary solid-state refrigeration drive of the exemplary embodiment of the present disclosure may further include a reducer 8. A rotary motor 9 is connected to the main transmission shaft 2 via the reducer 8. The reducer 8 is axially connected to the rotary motor 9 and the main transmission shaft 2 to increase the torque on the main transmission shaft 2. Furthermore, the rotary motor 9 of the rotary solid-state refrigeration drive of the exemplary embodiment of the present disclosure may be a servo motor, a stepper motor, a torque motor, a switched reluctance motor, a brushless DC motor, or the like, or may be a mechanical device capable of generating rotational motion.

[0059] As shown in FIG. 3 and FIG. 4 , the rotary solid-state refrigeration drive according to the exemplary embodiment of the present disclosure may further include a second external rack 7 a for fixing the speed reducer 8 and the eccentric transmission mechanism.

[0060] Furthermore, as shown in Figure 3, the rotary solid-state refrigeration drive according to an exemplary embodiment of the present disclosure may further include an upper housing portion 5a and a lower housing portion 5b. The upper housing portion 5a and the lower housing portion 5b serve as housing support portions, respectively supporting the piston 1 and the main drive shaft 2. A linear bearing 6 may be fixed to the upper housing portion 5a. The lower housing portion 5b may be fixedly connected to a second external frame 7a.

[0061] It should be noted that although the rotary solid-state refrigeration drive in the exemplary embodiment of the present disclosure adopts a two-cylinder structure, that is, the number of eccentric transmission mechanisms, pistons, and spring-loaded materials is two, the present invention is not limited to this. The rotary solid-state refrigeration drive may also adopt a three-cylinder, four-cylinder, or even more-cylinder structure. Optionally, when an N-cylinder structure is adopted, where N>2, the phase angle difference between any two adjacent eccentric transmission mechanisms is 360 / N degrees. In other words, for any intermediate eccentric transmission mechanism, if its phase angle is α, the phase angles of the adjacent eccentric transmission mechanisms in front and behind it can be α+360 / N and α+360 / N, respectively; alternatively, the phase angles of multiple eccentric transmission mechanisms do not have an increasing / decreasing relationship, as long as they are evenly distributed within a range of 360 degrees.

[0062] Under operating conditions, a rotary motor 9 drives the main drive shaft 2 through a reducer 8. The eccentric portion of the main drive shaft 2, the connecting rod portion 3, the pin 4, and the piston 1 form a crank-connecting rod structure. As the main drive shaft 2 rotates, the eccentric portion, through the annular portion, drives the connecting rod portion 3 to vibrate up and down and swing left and right. Simultaneously, because the upper end of the connecting rod portion 3 is connected to the piston 1, which is constrained by the linear bearing 6, the rotation of the main drive shaft 2 is converted into linear reciprocating motion of the piston 1. This reciprocating motion loads and unloads the spring-loaded material 10 on it, thereby inducing a snap-on effect. This snap-on effect refers to the release of heat into the environment by the spring-loaded material 10 during compression and the absorption of heat from the environment after recovery from deformation. Because the multiple eccentric drive mechanisms have different phase angles relative to the main drive shaft 2, the multiple pistons 1 achieve non-simultaneous linear reciprocating motion. Consequently, each spring-loaded material 10 is unloaded (or loaded) by the piston 1 at different times, resulting in different stages of deformation. During the unloading process, i.e., the deformation phase from compression to recovery, each spring-loaded material 10 exerts a downward thrust on piston 1. This thrust propels piston 1 downward, thereby simultaneously driving the eccentric transmission mechanism downward. The transmitted thrust acts tangentially on main drive shaft 2, providing rotational thrust. Because multiple spring-loaded materials 10 do not simultaneously exert thrust on main drive shaft 2, this thrust reduces the torque required to load other spring-loaded materials, achieving work recovery and promoting uniform rotation of main drive shaft 2. This reduces the input work of rotary motor 9 and achieves energy savings.

[0063] Optionally, the eccentric transmission mechanism according to the present disclosure may preferably have the structure described in the above embodiment, but may also have other structures. For example, the eccentric transmission mechanism may cooperate with the main transmission shaft 2 and the piston 1 to form an eccentric connecting rod mechanism, an eccentric cam mechanism, an eccentric bearing mechanism or a crank connecting rod mechanism. For example, when an eccentric cam mechanism is adopted, the main transmission shaft 2 may not be provided with an eccentric circle structure, and the connecting rod part 3 may be directly replaced by a cam fixed to the main transmission shaft 2, and the cam surface of the cam contacts the bottom of the piston 1 (so as to push the piston 1 when loading the card material or be pushed by the piston 1 when unloading the card material), and each cam has a different phase angle.

[0064] Optionally, the spring clip material 10 is selected from shape memory alloys, natural rubber, synthetic polymers, plastic crystals, etc. When the spring clip material 10 is a shape memory alloy, it can be selected from the group consisting of nickel titanium alloy, copper aluminum manganese alloy, nickel manganese titanium alloy, nickel titanium cobalt alloy, nickel titanium copper cobalt alloy, and nickel iron gallium alloy.

[0065] Optionally, the eccentric transmission mechanism, piston 1, main transmission shaft 2, linear bearing 6, upper housing part 5a and lower housing part 5b are formed of plastic, metal, resin or other materials through additive manufacturing (3D printing, etc.) or subtractive manufacturing (wire cutting, etc.).

[0066] Optionally, the rotation mode of the main transmission shaft 2 can be set to uniform rotation, differential rotation, or gap rotation.

[0067] Optionally, the deformation mode of each spring-strap material 10 during the loading-unloading process is a uniaxial linear deformation including linear compression and linear tension.

[0068] The rotary solid-state refrigeration driver disclosed herein is further described below in conjunction with experiments.

[0069] Related trials

[0070] The structure of the rotary solid-state refrigeration drive used in this experiment is shown in Figures 2 to 5. The linear bearing 6, second external frame 7a, first external frame 7b, reducer 8, and spring-loaded material 10 are commercial standard components. The piston 1, main drive shaft 2, connecting rod upper portion 3a, connecting rod lower portion 3b, pin 4, housing upper portion 5a, and housing lower portion 5b are machined alloy components. The components are connected by screws. The rotary motor 9 is a servo motor. For better demonstration purposes, a spring was used in place of spring-loaded material 10.

[0071] The operation of this rotary solid-state refrigeration drive is shown in Figure 1. The rotation of the rotary motor 9 causes the main drive shaft 2 to rotate. The eccentric transmission mechanism converts this rotation into linear reciprocating motion of the piston 1, thereby compressing the spring. Reverse unloading elastic mechanical work recovery occurs when the spring is unloaded, pushing the main drive shaft 2 to rotate, thereby reducing the torque required by the other loading spring.

[0072] The torque sensor is axially installed between the main transmission shaft 2 and the reducer 8 to measure the torque change on the main transmission shaft 2. Two springs that replace the spring-loaded material 10 are respectively installed in the two cylinders of the rotary solid-state refrigeration driver disclosed in the present invention. Among them, in the initial state, one spring is in a compressed state, that is, in a loaded state; the other spring is in a non-deformed state, that is, in an unloaded state. After the springs are installed, the rotary motor 9 is started, and the rotary motor 9 is set to work in a uniform rotation mode, and the speed is set to 16 revolutions per minute. The data of the torque on the shaft changing with the rotation angle of the transmission shaft is collected and recorded by the torque sensor. For comparison, the torque change of a solid-state refrigeration driver with only a single spring is collected.

[0073] The test results are shown in Figure 6. The area enclosed by the on-axis torque curve and the horizontal axis of the rotation angle represents the input work of the rotary motor 9. It can be seen that driving two materials simultaneously and utilizing the elastic unloading work of one material to drive the loading of the other requires less input work than driving the two materials separately (the area enclosed by the torque curve of twice a single material is greater than the area enclosed by the torque curves of both materials). Based on the principles described above, the unloading work recovery ratio of the driver can be roughly calculated using the following formula:

[0074] Where W1 refers to the mechanical work required for a single elastic material to be loaded and deformed without unloading work recovery, which refers to the area covered by the torque curve of a single material; the number 2 represents the number of drive cylinders (that is, the number of materials in the drive); W in It refers to the total mechanical work (measured value) required to realize the driving process under actual working conditions when using the rotary solid-state refrigeration driver disclosed in the present invention, which refers to the area wrapped by the torque curve of the double-root material; W2 refers to the unloaded mechanical work contained in a single-root material under working conditions. Generally speaking, for materials with a constant elastic modulus coefficient such as springs, W1 is equal to W2. Through calculation, it is found that the work recovery ratio is 53%, indicating that the rotary solid-state refrigeration driver disclosed in the present invention has the function of unloaded work recovery. If the unloaded elastic mechanical work of the material is recovered, the input work required for the rotary motor will be reduced to maintain the operation of the system, that is, to meet the requirement of reducing energy consumption.

[0075] Therefore, compared with the prior art, the rotary solid-state refrigeration drive disclosed in the present invention has the following advantages:

[0076] 1. Structural Design: This invention utilizes a rotary loading mechanism, significantly reducing the number of mechanical transmission devices compared to existing hydraulic or linear motor drives, thereby reducing mechanical and electrical energy losses. The multi-cylinder arrangement significantly reduces overall length, making the overall structure more compact.

[0077] 2. Energy utilization: The rotary solid-state refrigeration drive disclosed in the present invention realizes the recovery of mechanical work during unloading, and the recovered mechanical work of unloading one card material is used to load another card material, thereby realizing energy recovery and reducing energy consumption. Compared with traditional card materials that need to wait for heat dissipation before using the cooling capacity, this drive adopts a multi-cylinder design, and the intermittent cooling of multiple card materials can be superimposed into continuous cooling, which greatly improves the efficiency and cooling power. By adjusting the eccentric distance, the maximum single temperature reduction of the card material can be 30 degrees. The recovery of mechanical work during unloading does not require additional waiting time, and the overall drive operating frequency can be increased, reaching a maximum operating frequency of 5Hz, thereby obtaining a large cooling power.

[0078] 3. Commercial applications: Compared with existing hydraulic or linear motor drives, the rotary solid-state refrigeration drive disclosed in the present invention has greatly reduced overall weight and volume, and improved safety and portability. At the same time, since the drive only involves rotational motion during operation and has no additional mechanical transmission device, it has high overall mechanical stability and a high safety factor for use. Most importantly, it achieves unloading mechanical power recovery, and the energy consumption coefficient of the pop-up solid-state refrigerator will exceed that of existing air conditioners, which not only reduces consumers' electricity expenses, but also meets the needs of environmental protection and carbon neutrality.

[0079] In summary, the rotary solid-state refrigeration drive disclosed in the present invention utilizes the elastic mechanical energy stored in the spring-loaded material during the unloading process, realizes the recycling of the unloading mechanical work, reduces the power consumption required by the overall drive, improves the energy consumption ratio and the stability of the drive under working conditions, and provides new possibilities for the development of lightweight, commercial spring-loaded solid-state refrigeration devices.

[0080] In a second aspect, the present disclosure also provides a solid-state refrigeration device, which includes the rotary solid-state refrigeration drive based on unloading mechanical work recovery as described above, and also includes a heat exchange structure, which is used to exchange heat with the spring card material to transfer the heat and cold generated by the spring card material.

[0081] Optionally, the heat exchange structure may be a solid heat exchanger (directly transferring heat through solid-solid contact) or a fluid heat exchanger (using gas, liquid, liquid metal, etc. for solid-liquid convection heat exchange).

[0082] Since the solid-state refrigeration device includes the rotary solid-state refrigeration drive described above, it has all the advantages of the rotary solid-state refrigeration drive.

[0083] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A rotary solid-state refrigeration drive based on unloading mechanical work recovery, characterized in that: The rotary solid-state refrigeration driver comprises: a rotary motor, a main transmission shaft driven to rotate by the rotary motor, N eccentric transmission mechanisms installed at different axial positions of the main transmission shaft and driven by the main transmission shaft, N pistons driven to reciprocate by the N eccentric transmission mechanisms, and N ejection materials periodically loaded and unloaded by the reciprocating motion of the N pistons, wherein: N is an integer greater than 1; The N eccentric transmission mechanisms have different phase angles relative to the main transmission shaft, so that the time periods during which the N spring-stuck materials are unloaded are different; and Each ejection material provides thrust for the rotation of the main transmission shaft by releasing its own mechanical work during the unloading process.

2. The rotary solid-state refrigeration drive according to claim 1, characterized in that: Along the axial direction of the main transmission shaft, the phase angle difference between any two adjacent eccentric transmission mechanisms among the N eccentric transmission mechanisms is 360 / N degrees.

3. The rotary solid-state refrigeration driver according to claim 1 or 2, characterized in that: The eccentric transmission mechanism cooperates with the main transmission shaft and the piston to form an eccentric connecting rod mechanism, an eccentric cam mechanism, an eccentric bearing mechanism or a crank connecting rod mechanism.

4. The rotary solid-state refrigeration driver according to claim 1 or 2, characterized in that: At each of the different axial positions of the main transmission shaft: The cross section of the main transmission shaft is circular and the center of the circle does not coincide with the rotation axis of the main transmission shaft; and The eccentric transmission mechanism includes a connecting rod part and a pin, and the end of the connecting rod part away from the piston includes a circular ring part, and the circular ring part is sleeved on the main transmission part. The connecting rod part is on the outer circumferential surface of the driving shaft and can slide circumferentially relative to the outer circumferential surface of the main transmission shaft. The other end of the connecting rod part is hinged to the end of the piston away from the spring-stuck material through the pin.

5. The rotary solid-state refrigeration driver according to claim 4, characterized in that: The connecting rod part comprises an upper connecting rod part and a lower connecting rod part, the annular part is composed of the lower part of the upper connecting rod part and the lower connecting rod part, and the upper connecting rod part and the lower connecting rod part are connected together by screws.

6. The rotary solid-state refrigeration driver according to claim 5, characterized in that: Also includes: A linear bearing, which is sleeved outside the corresponding piston and is used to limit the direction of the reciprocating motion of the piston; A first external frame, which supports the corresponding piston and the spring-loaded material, and both ends of each spring-loaded material are fixed between the corresponding piston and the first external frame by direct contact, threaded connection, welding or bonding; and / or The upper housing portion and the lower housing portion are used to carry the piston and the main transmission shaft respectively.

7. The rotary solid-state refrigeration driver according to claim 1 or 2, characterized in that: The rotary motor is selected from: a servo motor, a stepper motor, a torque motor, a switched reluctance motor, a brushless DC motor, and The rotary solid-state refrigeration driver further includes a reducer, and the rotary motor drives the main transmission shaft to rotate via the reducer.

8. The rotary solid-state refrigeration driver according to claim 7, characterized in that: It also includes a second external frame for fixing the reducer and the eccentric transmission mechanism.

9. The rotary solid-state refrigeration driver according to claim 1 or 2, characterized in that: The geometric shape of the spring card material is selected from: cylindrical, cubic, cuboid, circular tube, rectangular tube; and The spring card material is selected from: shape memory alloy, natural rubber, synthetic polymer, and plastic crystal.

10. The rotary solid-state refrigeration driver according to claim 1 or 2, characterized in that: The deformation mode of the spring material during the loading-unloading process is uniaxial linear deformation, wherein the uniaxial linear deformation includes linear compression and linear tension.

11. A solid-state refrigeration device comprising: A rotary solid-state refrigeration drive based on unloading mechanical work recovery according to any one of claims 1 to 10; and The heat exchange structure is used to exchange heat with the spring card material to transfer the heat and cold generated by the spring card material.

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