Exterior driving type air conditioner heat conversion valve

Abstract

The application belongs to the technical field of cold-heat switching valves, and particularly relates to an external driving type air conditioner cold-heat switching valve, which comprises a valve body, a compressor exhaust pipe, a compressor suction pipe, an evaporator pipe and a condenser pipe connected to the valve body. A non-contact self-adaptive eddy current damping decoupling shaft coupling is arranged between the output shaft of the speed reducer and the driving rod. Under normal circumstances, the magnetic field coupling is used to transmit the rotary torque, so that the valve core is smoothly reversed. When the valve core head is impacted by cavitation and reversely transmitted, a transient speed difference is generated between the damping cup and the inner permanent magnet rotor. The speed difference cuts the magnetic field of the metal wall of the damping cup, eddy current is induced in the cup wall, and the reaction force of the eddy current becomes the braking torque, so that the impact energy is directly converted into heat on the damping cup and released, and the impact energy cannot be transmitted to the speed reducer and the motor. Therefore, the servo motor is not disturbed by the impact, and the speed reducer gear and the key groove are not repeatedly knocked to generate pits and wear.

Description

Technical Field

[0001] This invention relates to the field of cooling and heating switching valve technology, specifically an externally driven air conditioning cooling and heating switching valve. Background Technology

[0002] In air conditioning heat pump systems, four-way reversing valves or cooling / heating conversion valves typically use a motor, via a reducer and drive rod, to move the valve core, changing the connection between the compressor's exhaust port, intake port, and indoor / outdoor heat exchangers. To shorten switching time, the servo motor accelerates and decelerates rapidly. At the instant the valve core connects to the high and low pressure sides, dissolved gases in the refrigerant and refrigeration oil undergo flash evaporation. The resulting bubbles rapidly collapse upon pressure recovery, creating a high-frequency water hammer impact on the valve core's end face. This impact is significant, with a wide bandwidth and high peak value, and is transmitted back through the shift fork and drive rod to the reducer's gear pair and the motor rotor. Over time, this can cause glitch development in the servo motor's encoder feedback signal, leading to unstable current loop control, pitting on the reducer gear surface, and increased wear at the keyway connecting the drive rod and the reducer output shaft, directly affecting the valve's lifespan and switching reliability.

[0003] Furthermore, if impact energy accumulates on the damping element for an extended period, the element itself will continuously heat up, and its temperature will rise. Once this temperature exceeds the material's tolerance limit, the damping performance will deteriorate, potentially leading to element failure. Current eddy current damping solutions generally lack overheat protection mechanisms, either relying on external temperature sensors and controllers to cut off the drive or simply leaving it unprotected, relying on the material to withstand the heat. The former increases system complexity and cost, while the latter poses reliability risks.

[0004] Traditional methods to isolate this impact involve adding a flexible coupling or rubber buffer between the drive rod and the reducer. However, flexible components can only absorb low-frequency vibrations and are largely ineffective at isolating impacts of milliseconds or even shorter durations caused by cavitation collapse. Furthermore, these flexible components are prone to fatigue and aging. Some solutions attempt to filter out the speed fluctuations caused by the impact through notch filters in electrical control, but this is a passive approach; the mechanical energy of the impact still enters the transmission chain, causing wear. Therefore, to date, no effective method has been found in the market for externally driven directional valves that directly cuts off the impact transmission along the mechanical transmission path while also possessing self-overheat protection capabilities. Summary of the Invention

[0005] The present invention aims to solve one of the technical problems existing in the prior art or related technologies.

[0006] Therefore, the technical solution adopted in this invention is as follows: An externally driven air conditioning cooling and heating conversion valve includes a valve body, on which a compressor exhaust pipe, a compressor suction pipe, an evaporator pipe, and a condenser pipe are connected. The valve body is provided with a valve core that can move axially back and forth. A drive rod is connected to the valve core. The outer end of the drive rod is connected to a motor drive via a reducer. A set of non-contact adaptive eddy current damping decoupling couplings is connected in series between the output shaft of the reducer and the outer end of the drive rod; The non-contact adaptive eddy current damping decoupling coupling includes an inner permanent magnet rotor fixed on the output shaft of the reducer and a damping cup fixed on the outer end of the drive rod. The damping cup is a cylindrical part made of conductive metal, with the cup opening facing the motor side and coaxially sleeved on the outside of the inner permanent magnet rotor. A radial air gap is left between the inner wall surface of the damping cup and the outer surface of the inner permanent magnet rotor. During steady-state transmission, the two rotate synchronously by magnetic field coupling. When the valve core is switched between hot and cold modes and is subjected to a reverse impact caused by the cavitation collapse of the refrigerant, the impact causes the damping cup to slow down instantaneously via the drive rod. Meanwhile, the inner permanent magnet rotor maintains its original speed due to the inertia of the motor. A speed difference appears between the two. The inner wall of the damping cup cuts the magnetic field generated by the inner permanent magnet rotor, inducing eddy currents in the cup wall. The magnetic force on the eddy currents acts in the opposite direction on the damping cup to generate a braking torque, converting the impact kinetic energy into heat dissipation in the cup wall. This mechanically cuts off the path for the impact to continue to be transmitted to the reducer and motor.

[0007] In a preferred embodiment, the present invention can be further configured such that: the cylindrical cup wall of the damping cup is composed of two layers of different metals, the inner layer being a copper layer and the outer layer being a shape memory alloy layer, and the two layers are metallurgically bonded together. The copper layer serves as the main carrier for eddy current heating, and the high-temperature phase shape of the shape memory alloy layer is set to expand radially outward. When the impact accumulates and causes the cup wall temperature to exceed its phase transition temperature, the shape memory alloy layer drives the entire cup wall to expand and deform radially outward, increasing the radial air gap, thereby weakening the eddy current damping effect and preventing the impact torque from continuing to be transmitted to the reducer and motor, thus playing an overheat protection role.

[0008] In a preferred embodiment, the present invention may be further configured such that the thickness of the shape memory alloy layer accounts for 30% to 40% of the total thickness of the damping cup wall, with the remainder being the thickness of the copper layer.

[0009] In a preferred embodiment, the present invention can be further configured such that: at least two spiral expansion joints are provided on the cylindrical sidewall of the damping cup, the spiral expansion joints extend axially along the cylindrical wall and do not penetrate near the cup opening, dividing the cylindrical wall into multiple independent cantilever damping fins; The spiral expansion joint allows the wall of the damping cup to bend and open outward uniformly when it expands radially outward under the drive of the shape memory alloy layer, preventing irregular deformation or tearing of the wall.

[0010] In a preferred embodiment, the present invention can be further configured such that the helix angle of the spiral expansion joint is 30° to 60°, which elongates the actual conductive path of the induced eddy current on the damping fin, increases the equivalent resistance, and suppresses the skin effect caused by high-frequency impact.

[0011] In a preferred embodiment, the present invention can be further configured such that the width of the spiral expansion joint is 0.2 mm to 0.5 mm, and when the damping fin is subjected to impact and generates a small radial vibration, the gas or oil in the joint is rapidly squeezed to form a compression film to add a portion of viscous energy dissipation.

[0012] In a preferred embodiment, the present invention can be further configured such that: the inner permanent magnet rotor consists of a rotor yoke and multiple permanent magnets embedded on the outer cylindrical surface of the rotor yoke; the rotor yoke is fixed to the output shaft of the reducer; and a fixed non-magnetic metal isolation sleeve is fitted around the permanent magnets; the non-magnetic metal isolation sleeve is located between the permanent magnets and the damping cup and does not contact either of them.

[0013] In a preferred embodiment, the present invention can be further configured such that: a flange is machined at the outer end of the drive rod, the damping cup is cylindrical, and the bottom of the cylinder is fixed to the flange by bolts.

[0014] In a preferred embodiment, the present invention may be further configured such that: the drive rod includes a connecting section fixedly connected to the valve core and a drive section threadedly connected to the outer end of the connecting section, and a sealing block fixed to the inner wall of the valve body is fitted at the junction of the connecting section and the drive section to improve the sealing between the drive section and the valve body.

[0015] In a preferred embodiment, the present invention can be further configured such that: the non-magnetic metal isolation sleeve is made of austenitic stainless steel with a resistivity of not less than 0.7 μΩ·m, which is much higher than the resistivity of copper used in the damping cup, so that when the rotating magnetic field penetrates the non-magnetic metal isolation sleeve, no obvious eddy currents are generated on the non-magnetic metal isolation sleeve, and the eddy currents are concentrated only in the cup wall of the damping cup to generate damping and heat.

[0016] The above-described technical solution of the present invention has the following beneficial technical effects: First, a non-contact adaptive eddy current damping decoupling coupling is installed between the reducer output shaft and the drive rod. Under normal circumstances, the rotational torque is transmitted through magnetic field coupling to ensure smooth valve core reversal. When the valve core is subjected to a cavitation impact and the impact is transmitted back in the opposite direction, an instantaneous speed difference is generated between the damping cup and the inner permanent magnet rotor. This speed difference causes the metal wall of the damping cup to cut the magnetic field, inducing eddy currents in the cup wall. The reaction force of the eddy currents becomes a braking torque, directly releasing the impact energy as heat on the damping cup, without transmitting it to the reducer and motor. In this way, the servo motor will not be affected by the impact, and the reducer gears and keyways will not be repeatedly struck, resulting in pitting and wear.

[0017] Secondly, the damping cup's cylinder wall is made with a double-layer composite structure: an inner copper layer and an outer shape memory alloy layer. The high-temperature phase shape of the shape memory alloy layer is set to expand radially outward. During normal operation, impact energy is converted into heat on the copper layer, the cup wall temperature remains within the normal range, the shape memory alloy layer does not undergo a phase change, the damping cup maintains a normal air gap, and eddy current damping functions normally to dissipate energy. However, if continuous, prolonged impacts cause the cup wall temperature to rise abnormally, exceeding the phase change temperature of the shape memory alloy layer, the shape memory alloy layer will drive the entire cup wall to expand and deform outward, increasing the radial air gap, decreasing the magnetic flux density, automatically weakening the eddy current damping effect, further cutting off the impact torque transmission path, and automatically reducing heat generation. This creates an opportunity for the damping cup to actively cool down, providing overheat protection. This process requires no intervention from sensors or controllers; it is achieved solely through the physical properties of the materials themselves.

[0018] Third, spiral expansion joints are cut into the wall of the damping cup, dividing the entire cup into several fins. When the shape memory alloy layer drives the cup wall to expand outward, these spiral joints allow the fins to bend and open evenly, preventing irregular deformation or tearing due to localized stress concentration. Simultaneously, the spiral joints intentionally lengthen the flow path of eddy currents within the cup, effectively increasing the resistance in the conductive circuit. This prevents eddy currents from concentrating only in a shallow surface area during high-frequency impacts, ensuring the damping effect doesn't diminish at high frequencies. Furthermore, the spiral joints themselves are very narrow, compressing the oil film or gas within them during cup deformation or vibration, thus also absorbing some of the vibrational energy. The entire structural modification is concentrated on the coupling; the main structure and installation method of the valve body, valve core, and drive rod do not require major alterations and can be easily implemented in existing products. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view of an externally driven air conditioning cooling / heating conversion valve according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a non-contact adaptive eddy current damping decoupling coupling according to an embodiment of the present invention.

[0020] Figure label: 1. Valve body; 11. Compressor exhaust pipe; 12. Compressor suction pipe; 13. Evaporator pipe; 14. Condenser pipe; 2. Valve core; 21. Fork groove; 3. Drive rod; 31. Connecting section; 32. Drive section; 33. Flange; 34. Sealing block; 4. Motor; 5. Reducer; 51. Reducer output shaft; 6. Non-contact adaptive eddy current damping decoupling coupling; 61. Internal permanent magnet rotor; 611. Rotor yoke; 612. Permanent magnet; 62. Non-magnetic metal isolation sleeve; 7. Damping cup; 71. Copper layer; 72. Shape memory alloy layer; 73. Spiral expansion joint; 74. Damping fins; g. Radial air gap. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0022] It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the invention.

[0023] The following describes, with reference to the accompanying drawings, some embodiments of the externally driven air conditioning cooling / heating conversion valve provided by the present invention.

[0024] Combination Figures 1-2 As shown, the externally driven air conditioning cooling / heating conversion valve provided by this invention comprises several main parts: a valve body 1, a valve core 2, a drive rod 3, a motor 4, a reducer 5, and a non-contact adaptive eddy current damping decoupling coupling 6 connected in series between the reducer 5 and the drive rod 3. The valve body 1 is a multi-port cavity with four interfaces machined on its side walls: a compressor exhaust pipe 11, a compressor suction pipe 12, an evaporator pipe 13, and a condenser pipe 14. These interfaces are respectively connected to the compressor exhaust side, compressor suction side, and indoor / outdoor heat exchangers of the air conditioning system. A slide valve core 2 is installed inside the valve body 1. The valve core 2 can slide back and forth axially. By changing the position of different annular grooves on it, the on / off relationship between the four interfaces is switched, realizing the conversion between cooling and heating modes. The drive rod 3 is connected to the valve core 2. The outer end of the drive rod 3 is connected to the motor 4 via the reducer 5. The power of the motor 4 is amplified by the reducer 5 and transmitted to the drive rod 3, which then drives the valve core 2 to move.

[0025] A set of non-contact adaptive eddy current damping decoupling couplings 6 are connected in series between the output shaft of the reducer 5 and the outer end of the drive rod 3. Structurally, this coupling consists of two main parts: an inner permanent magnet rotor 61 fixed to the output shaft 51 of the reducer, and a damping cup 7 fixed to the outer end of the drive rod 3. The two are coaxially fitted but not in direct contact. The damping cup 7 is a cylindrical part made of conductive metal, with its opening facing the motor 4 and coaxially fitted around the inner permanent magnet rotor 61. A radial air gap g is left between the inner wall of the damping cup 7 and the outer surface of the inner permanent magnet rotor 61. Under normal assembly conditions, this radial air gap g is approximately 0.3mm to 0.8mm. During steady-state transmission, the two rotate synchronously through magnetic field coupling. That is, the rotating magnetic field generated by the inner permanent magnet rotor 61 passes through the radial air gap g, inducing eddy currents within the wall of the damping cup 7. The eddy currents interact with the magnetic field to generate magnetic force, pulling the damping cup 7 to rotate along with it, thus achieving non-contact torque transmission.

[0026] It should be noted that when valve core 2 switches between hot and cold modes, the high-pressure chamber and the low-pressure chamber are momentarily connected. The bubbles generated by the flash evaporation of refrigerant dissolved in the refrigeration oil quickly collapse when the pressure is restored, creating a high-frequency water hammer impact on the end face of valve core 2. This impact is transmitted to the damping cup 7 via the drive rod 3, causing the speed of the damping cup 7 to slow down in a very short time. Meanwhile, the inner permanent magnet rotor 61 maintains almost its original speed under the inertia of the motor 4 rotor, resulting in a speed difference between the two. At this time, the inner wall of the damping cup 7 rapidly cuts the magnetic field generated by the inner permanent magnet rotor 61, inducing strong eddy currents in the cup wall of the damping cup 7. The magnetic force on the eddy currents acts in the opposite direction to the damping cup 7, generating a braking torque opposite to the direction of motion, directly converting the kinetic energy brought by the impact into Joule heat dissipation of the cup wall. In this way, the impact energy is absorbed and converted into heat at the damping cup 7 stage, and will not continue to be transmitted along the transmission chain to the reducer 5 and motor 4, cutting off the transmission of the impact from the mechanical path.

[0027] Furthermore, the cylindrical wall of the damping cup 7 is not a single layer of metal, but rather a composite of two different metals. The inner layer is a copper layer 71, and the outer layer is a shape memory alloy layer 72. The two layers are metallurgically bonded together by explosive welding or hot isostatic diffusion welding to ensure heat conduction and interface strength. The copper layer 71 serves as the main carrier for eddy current heating, while the shape memory alloy layer 72 is a nickel-titanium shape memory alloy. Unlike conventional approaches, in this embodiment, the high-temperature phase shape of the shape memory alloy layer 72 is pre-programmed to expand radially outward. That is, when heated above the phase transition temperature, it drives the entire cup wall to expand outward. The thickness of the shape memory alloy layer 72 accounts for 30% to 40% of the total thickness of the damping cup 7 wall, with the remaining thickness being the copper layer 71. This proportion ensures both eddy current heating efficiency and sufficient driving force for the shape memory alloy layer 72 during phase transition.

[0028] During a normal single reversal, the heat generated by cavitation impact is limited, and the cup wall temperature remains below the austenite transformation end temperature Af of the shape memory alloy layer 72. The shape memory alloy layer 72 remains unchanged, the radial air gap g remains constant, and eddy current damping dissipates energy normally. However, if multiple reversals occur consecutively due to special operating conditions, the impact energy continuously accumulates on the damping cup 7. Eddy current heating causes the cup wall temperature to rise continuously. Once the phase transformation temperature is exceeded, the shape memory alloy layer 72 will undergo a martensitic-to-parent phase transformation. Because its high-temperature phase shape is set to expand outward, it will drive the entire cup wall to expand and deform radially outward. This results in a significant increase in the radial air gap g, an increase in magnetic circuit reluctance, and a significant decrease in magnetic flux density passing through the damping cup 7. Consequently, the eddy current damping effect automatically weakens. With reduced damping, on the one hand, the transmission path of the impact torque to the reducer 5 and motor 4 is further blocked; on the other hand, the eddy current heat generation also automatically decreases, creating an opportunity for the damping cup 7 to cool down. Once the temperature drops below the phase transition temperature, the shape memory alloy layer 72 softens, the cup wall springs back to its original position under its own elasticity, the radial air gap g is restored, and the damping function is also restored. The entire overheat protection process does not require sensors or controllers; it is entirely triggered and restored automatically by the material's own properties.

[0029] Specifically, to ensure uniform deformation of the cup wall as the shape memory alloy layer 72 expands outward, at least two spiral expansion joints 73 are formed on the cylindrical sidewall of the damping cup 7. These spiral expansion joints 73 extend axially along the cylindrical wall, starting from the cup mouth and ending near the bottom but not penetrating to the bottom, dividing the cylindrical wall into multiple independent cantilevered damping fins 74. When the shape memory alloy layer 72 drives the cup wall to expand outward, each damping fin 74 acts like an arc-shaped cantilever beam with one end fixed and the other free, bending and opening outward uniformly in the radial direction. This prevents the complete cylinder from undergoing irregular deformation or even tearing due to excessive tensile stress in the circumferential direction during expansion, ensuring the consistency of the radial air gap g in the circumferential direction.

[0030] The helix angle of the spiral expansion joint 73 should ideally be between 30° and 60°. Within this angle range, the actual conductive path of the induced eddy current on the damping fin 74 is forcibly lengthened by the spiral joint, resulting in a corresponding increase in equivalent resistance. This alleviates the problem of eddy currents flowing only in a thin surface layer due to the skin effect under high-frequency impact, and the damping effect can be maintained even at high frequencies. The width of the spiral expansion joint 73 is controlled between 0.2mm and 0.5mm. When the damping fin 74 is impacted and produces a small radial vibration or expands outward, the small amount of refrigerant oil vapor or air originally stored in the joint is rapidly compressed, forming a compression film. This provides additional viscous energy dissipation and plays an auxiliary role in vibration reduction.

[0031] It should be noted that the internal permanent magnet rotor 61 specifically consists of a rotor yoke 611 and multiple permanent magnets 612 embedded in the outer cylindrical surface of the rotor yoke 611. The rotor yoke 611 is made of soft magnetic materials such as electrical pure iron and is fixed to the stepped shaft section at the end of the reducer output shaft 51 by a flat key or thermal mounting. The outer cylindrical surface of the rotor yoke 611 has axial grooves, and each permanent magnet 612 is embedded in the groove. The magnetic poles of adjacent permanent magnets 612 are arranged alternately to form a multi-pole magnetic field. A fixed non-magnetic metal isolation sleeve 62 is also fitted over the permanent magnets 612. This non-magnetic metal isolation sleeve 62 is fixed on the stationary motor bracket, located between the permanent magnets 612 and the damping cup 7, and does not contact either of them. The non-magnetic metal isolation sleeve 62 is made of austenitic stainless steel with a resistivity of not less than 0.7 μΩ·m, which is much higher than the resistivity of the copper used in the damping cup 7. This means that when the rotating magnetic field penetrates the non-magnetic metal isolation sleeve 62, almost no eddy currents are generated on it; the eddy currents are concentrated only within the cup wall of the damping cup 7, generating damping and heat. Simultaneously, the non-magnetic metal isolation sleeve 62 also isolates the area where the permanent magnet 612 is located from any external refrigerant or oil vapors that may enter, preventing the permanent magnet 612 from being corroded or attracting iron filings.

[0032] A flange 33 is machined onto the outer end of the drive rod 3. The damping cup 7 is a cylindrical part, and its bottom is fixed to the flange 33 with bolts, allowing the damping cup 7 to rotate with the drive rod 3. The drive rod 3 itself consists of a connecting section 31 fixedly connected to the valve core 2 and a drive section 32 threadedly connected to the outer end of the connecting section 31. A sealing block 34, fixed to the inner wall of the valve body 1, is fitted at the junction of the connecting section 31 and the drive section 32. The sealing block 34 improves the sealing between the drive section 32 and the valve body 1, preventing refrigerant and refrigeration oil inside the valve body 1 from leaking outwards along the drive rod 3.

[0033] In terms of overall assembly and workflow, the motor 4 and reducer 5 are fixed as a power assembly on a bracket on the outside of the valve body 1. After the reducer output shaft 51 extends, the inner permanent magnet rotor 61 is installed first, followed by the non-magnetic metal isolation sleeve 62. Then, the damping cup 7, which is already fixed to the drive rod 3, is put on the outside, maintaining a radial air gap g between the inner wall of the damping cup 7 and the outer surface of the inner permanent magnet rotor 61. The drive rod 3 passes through the end cover of the valve body 1, and its connecting section 31 is fixed to the valve core 2. The drive section 32 is threadedly connected to the connecting section 31, and the sealing block 34 is pressed against the junction for sealing. The entire transmission chain is as follows: motor 4, reducer 5, reducer output shaft 51, inner permanent magnet rotor 61, damping cup 7, drive rod 3, and finally reaches the valve core 2. When the system receives a reversing command, the motor 4 is powered on and rotates, pushing the valve core 2 to move through the above transmission path, changing the on / off relationship of the four interfaces, and completing the switching between cooling and heating. The cavitation impact at the moment of switching is converted into heat dissipation by eddy current damping at the damping cup 7, and the motor 4 runs smoothly. If continuous impacts cause the cup wall to overheat, the shape memory alloy layer 72 automatically expands outward to increase the radial air gap g to weaken damping and reduce heat generation. After the temperature drops, it recovers on its own, realizing the dual functions of impact isolation and overheat protection.

[0034] The various electrical devices mentioned in this application are all conventional or standard components that achieve their corresponding functions. Those skilled in the art, based on their professional knowledge and the teachings of this application, can select appropriate models and specifications for implementation without creative effort. The exact models of these components are not the innovation of this invention, and minor differences in their specific specifications do not affect the realization of the core technical effects of this application; therefore, they are not individually limited in the specification.

[0035] In this invention, the term "a plurality of" refers to two or more unless otherwise expressly defined. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. The terms "installed," "connected," "linked," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "linked" can be a direct connection or an indirect connection via an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] It should be noted that when a component is referred to as being "assembled on," "mounted on," "fixed to," or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0037] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0038] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An externally driven air conditioning cooling / heating conversion valve, comprising a valve body (1), wherein a compressor exhaust pipe (11), a compressor suction pipe (12), an evaporator pipe (13), and a condenser pipe (14) are connected to the valve body (1), and a valve core (2) capable of axial reciprocating movement is provided inside the valve body (1), and a drive rod (3) is connected to the valve core (2), characterized in that: The outer end of the drive rod (3) is connected to the motor (4) via a reducer (5); A set of non-contact adaptive eddy current damping decoupling couplings (6) are connected in series between the reducer output shaft (51) of the reducer (5) and the outer end of the drive rod (3). The non-contact adaptive eddy current damping decoupling coupling (6) includes an inner permanent magnet rotor (61) fixed on the output shaft (51) of the reducer and a damping cup (7) fixed on the outer end of the drive rod (3). The damping cup (7) is a cylindrical part made of conductive metal. The cup opening faces the motor (4) and is coaxially sleeved on the outside of the inner permanent magnet rotor (61). A radial air gap (g) is left between the inner wall surface of the damping cup (7) and the outer surface of the inner permanent magnet rotor (61). During steady-state transmission, the two rotate synchronously by magnetic field coupling.

2. The externally driven air conditioning cooling / heating conversion valve according to claim 1, characterized in that, The cylindrical cup wall of the damping cup (7) is composed of two layers of different metals. The inner layer is a copper layer (71) and the outer layer is a shape memory alloy layer (72). The two layers are metallurgically bonded together. The copper layer (71) serves as the main carrier for eddy current heating, and the high-temperature phase shape of the shape memory alloy layer (72) is set to expand radially outward. When the impact accumulates and causes the cup wall temperature to exceed its phase transition temperature, the shape memory alloy layer (72) drives the entire cup wall to expand and deform radially outward, increasing the radial air gap (g), thereby weakening the eddy current damping effect and preventing the impact torque from continuing to be transmitted to the reducer (5) and motor (4), thus playing an overheat protection role.

3. The externally driven air conditioning cooling / heating conversion valve according to claim 2, characterized in that, The thickness of the shape memory alloy layer (72) accounts for 30% to 40% of the total thickness of the damping cup (7) wall, and the remainder is the thickness of the copper layer (71).

4. The externally driven air conditioning cooling / heating conversion valve according to claim 2, characterized in that, At least two spiral expansion joints (73) are provided on the cylindrical side wall of the damping cup (7). The spiral expansion joints (73) extend axially along the cylindrical wall and do not penetrate near the cup opening, dividing the cylindrical wall into multiple independent cantilever damping fins (74).

5. The externally driven air conditioning cooling / heating conversion valve according to claim 4, characterized in that, The spiral angle of the spiral expansion joint (73) is 30° to 60°, which lengthens the actual conductive path of the induced eddy current on the damping fin (74) and increases the equivalent resistance.

6. The externally driven air conditioning cooling / heating conversion valve according to claim 4 or 5, characterized in that, The width of the spiral expansion joint (73) is 0.2 mm to 0.5 mm.

7. The externally driven air conditioning cooling / heating conversion valve according to claim 1, characterized in that, The inner permanent magnet rotor (61) consists of a rotor yoke (611) and multiple permanent magnets (612) embedded on the outer cylindrical surface of the rotor yoke (611). The rotor yoke (611) is fixed on the output shaft (51) of the reducer. A fixed non-magnetic metal isolation sleeve (62) is fitted around the permanent magnet (612). The non-magnetic metal isolation sleeve (62) is located between the permanent magnet (612) and the damping cup (7) and does not contact either of them.

8. The externally driven air conditioning cooling / heating conversion valve according to claim 1, characterized in that, The outer end of the drive rod (3) is machined with a flange (33), and the damping cup (7) is cylindrical, with the bottom of the cylinder fixed to the flange (33) by bolts.

9. The externally driven air conditioning cooling / heating conversion valve according to claim 1, characterized in that, The drive rod (3) includes a connecting section (31) fixedly connected to the valve core (2) and a drive section (32) threadedly connected to the outer end of the connecting section (31). A sealing block (34) fixed to the inner wall of the valve body (1) is fitted at the junction of the connecting section (31) and the drive section (32).

10. The externally driven air conditioning cooling / heating conversion valve according to claim 7, characterized in that, The non-magnetic metal isolation sleeve (62) is made of austenitic stainless steel, and its resistivity is not less than 0.7 μΩ·m, which is much higher than the resistivity of the copper used in the damping cup (7). This ensures that when the rotating magnetic field penetrates the non-magnetic metal isolation sleeve (62), no obvious eddy currents are generated on the non-magnetic metal isolation sleeve (62). The eddy currents are concentrated only in the cup wall of the damping cup (7) to generate damping and heat.

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