Robot joint motor based on synergistic heat dissipation of vapor chamber and hydrogel

Abstract

The invention discloses a robot joint motor based on synergistic heat dissipation of a vapor chamber and hydrogel. Comprising a vapor chamber, a stator assembly, a rotor assembly, an evaporation heat dissipation assembly, a motor shell and an output end cover. One end of the motor shell is connected with the outside through the output end cover, and the other end is provided and connected with an evaporation heat dissipation assembly; a soaking plate, a stator assembly and a rotor assembly are arranged in the motor shell; one end of the rotor assembly is connected with the output end cover, and the other end of the rotor assembly is connected with the evaporation heat dissipation assembly; the stator assembly is in close contact with one end of the vapor chamber, and the other end of the vapor chamber is connected with the evaporation heat dissipation assembly; the evaporation heat dissipation assembly comprises hydrogel, the hydrogel absorbs heat conducted to the heat dissipation end cover through the vapor chamber, and the heat is efficiently dissipated to the surrounding environment through water evaporation. Through the synergistic effect of heat conduction of the vapor chamber and evaporation heat dissipation of the hydrogel, passive efficient heat dissipation of the joint motor is achieved, energy consumption is zero, and no extra space is occupied.

Description

Technical Field

[0001] This invention relates to the field of robot joint motor technology, and in particular to a robot joint motor based on heat dissipation through a heat spreader and hydrogel. Background Technology

[0002] With the continuous development of embodied intelligence technology, humanoid robots, as an important carrier, are receiving widespread attention from academia and industry. As the core drive unit of robots, articulated motors face higher requirements in terms of power density, lightweight design, and structural compactness. However, under harsh operating conditions such as high power output, continuous load, and long-term operation, heat easily accumulates inside the motor, causing a significant temperature rise, which in turn affects its output performance and operational reliability. Therefore, efficient thermal management has become a crucial issue that cannot be ignored in the design of articulated motors.

[0003] Current common heat dissipation methods, such as adding heat sink fins to the outer shell or using fans for forced ventilation, can alleviate temperature rise to some extent, but their heat dissipation efficiency is still insufficient for high-power-density joint motors. The introduction of fans also occupies additional structural space, increasing system complexity and noise. While liquid cooling solutions offer strong heat dissipation capabilities, they typically require complex cooling channels and rely on liquid pumps, leading to additional power losses and the risk of coolant leakage. Considering that humanoid robots usually integrate multiple joint motors, traditional cooling solutions have limitations in terms of overall reliability, integration, and energy efficiency.

[0004] In recent years, researchers have begun exploring efficient heat dissipation paths between the main internal heat sources and the external casing of electric motors. For example, insulating materials such as thermally conductive resins or highly thermally conductive adhesives are used to fill the gap between the motor end windings and the casing to create auxiliary heat conduction channels and improve heat transfer. However, these materials themselves have limited thermal conductivity. Furthermore, although enhanced heat conduction from the heat source to the casing is achieved, the heat ultimately still relies on natural convection between the casing surface and the environment for dissipation, and the overall heat dissipation bottleneck remains unresolved.

[0005] Against this backdrop, there is an urgent need for an integrated heat dissipation solution that can achieve high efficiency, no additional energy consumption, and collaboratively solve internal and external heat dissipation bottlenecks, in order to meet the stable and long-term operation of high power density robot joint motors. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes a robot joint motor based on the synergistic heat dissipation of a heat spreader and hydrogel. The heat spreader rapidly transfers heat from the windings to the end cap, while the evaporation of moisture from the hydrogel on the end cap enables efficient heat dissipation of the joint motor.

[0007] The technical solution adopted in this invention is: A robot joint motor based on the synergistic heat dissipation of a heat spreader and hydrogel includes a heat spreader, a stator assembly, a rotor assembly, an evaporative cooling assembly, a motor housing, and an output end cap. One end of the motor housing is connected to the external robot joint via the output end cap, and the other end of the motor housing is provided and connected to the evaporative cooling assembly. An inner cavity is provided inside the motor housing, and the heat spreader, stator assembly, and rotor assembly are coaxially arranged within the inner cavity. The rotor assembly is located within the stator assembly, with one end connected to the output end cap and the other end connected to the evaporative cooling assembly. The end of the stator assembly closest to the evaporative cooling assembly is connected to one end of the heat spreader, and the other end of the heat spreader is connected to the evaporative cooling assembly. The evaporative cooling assembly includes hydrogel for heat dissipation. The hydrogel absorbs the heat generated at the robot joint via the heat spreader and conducts it to the cooling end cap, and efficiently dissipates the heat to the surrounding environment through water evaporation.

[0008] The heat spreader adopts a near-ring-shaped structure, comprising a heat spreader ring, a heat spreader condensing end annular boss, and a heat spreader evaporating end boss. The two sides of the heat spreader ring are the heat spreader condensing end and the heat spreader evaporating end, respectively. A heat spreader condensing end annular boss is provided on the end face of the heat spreader condensing end, and the heat spreader condensing end annular boss is coaxially arranged with the heat spreader ring. Multiple heat spreader evaporating end bosses are provided on the heat spreader evaporating end, and the heat spreader evaporating end bosses are arranged at equal intervals along the circumference on the heat spreader evaporating end. The end of the heat spreader evaporating end boss away from the heat spreader is embedded in the stator assembly, and the end of the heat spreader condensing end annular boss away from the heat spreader is connected to the heat dissipation end cap.

[0009] The stator assembly includes a motor stator, a stator sealing shell, stator windings, a sealing plate, and thermally conductive adhesive; the motor stator is mounted on the stator sealing shell and connected to the heat spreader plate via the motor stator.

[0010] The stator sealing shell adopts a near-ring structure. The outer edge of the stator sealing shell near the motor stator is provided with a flange, and the inner edge is provided with a plurality of sealing plates arranged circumferentially and at equal intervals facing the motor stator. The diameter of the flange of the stator sealing shell matches the diameter of the motor stator. The motor stator is provided with a plurality of stator windings arranged circumferentially and at equal intervals. The interval between every two stator windings forms a stator slot. Each sealing plate and each heat spreader evaporation end boss are embedded in a corresponding stator slot. The remaining space in the stator slot is filled with thermally conductive adhesive.

[0011] The number of sealing inserts, evaporator end bosses of heat spreaders, stator windings, and stator slots are equal and their positions are matched. After the sealing inserts and evaporator end bosses of heat spreaders are inserted into a stator slot, the evaporator end of the heat spreader is in close contact with the end face of the stator winding near the heat spreader, and the sealing inserts are in close contact with the stator winding. Each stator slot is enclosed by the motor housing, motor stator, stator windings, sealing inserts, and heat spreader to form a sealed stator cavity, and each stator cavity is filled with thermally conductive adhesive.

[0012] The evaporative heat dissipation assembly includes a heat dissipation end cap, hydrogel, and a dustproof net. One side of the heat dissipation end cap is connected to the heat spreader and the rotor assembly, and the other end of the heat dissipation end cap is connected to the dustproof net. The gap between the heat dissipation end cap and the dustproof net is filled with hydrogel.

[0013] The side of the heat dissipation end cap closest to the heat spreader is the inner side of the heat dissipation end cap, and the other side is the outer side of the heat dissipation end cap; the inner side of the heat dissipation end cap is recessed inward to form a positioning groove, which is used to connect with the annular boss of the condensing end of the heat spreader plate with a gap, and the gap between the annular boss of the condensing end of the heat spreader plate and the positioning groove is filled with thermally conductive adhesive.

[0014] The heat dissipation end cap has multiple coaxially arranged annular heat dissipation end cap fins arranged from the center outwards on the outer side. A hydrogel filling groove is formed between every two annular heat dissipation end cap fins, and the hydrogel filling groove is used to fill hydrogel.

[0015] The dustproof net has multiple dense mesh holes, which are arranged in a radial concentric circle pattern from the inside out, with the center as the center. The dense mesh holes are used to allow the water in the hydrogel to evaporate and diffuse into the air.

[0016] The rotor assembly includes a motor rotor and a reducer. The reducer is arranged at a distance from the stator assembly. An output through hole is provided in the middle of the output end cover. The reducer is arranged inside the housing cavity and connected to the output end cover. One end of the reducer near the output end cover is located in the output through hole. The motor rotor and the reducer are fixedly connected. One end of the motor rotor is connected to the outside through the reducer. The other end of the motor rotor is located inside the stator assembly and is in clearance fit with the stator winding and sealing plate in the stator assembly.

[0017] The hydrogel is a PAM hydrogel, which is prepared using the following method: S1. Dissolve acrylamide monomer and crosslinking agent N,N'-methylenebisacrylamide in deionized water and stir thoroughly to form a precursor solution; S2. Add potassium persulfate as an initiator to the precursor solution and stir thoroughly under heating at 50°C, so that the potassium persulfate initiator initiates the cross-linking reaction of the precursor solution itself. After the precursor solution is cured by the cross-linking reaction, a PAM hydrogel is formed.

[0018] The mass ratio of the acrylamide monomer, the crosslinking agent N,N'-methylenebisacrylamide, and deionized water is 10:0.1:90~100; the mass ratio of the initiator potassium persulfate to the acrylamide monomer in the precursor solution is 1:100.

[0019] The beneficial effects of this invention are: This invention establishes an additional heat dissipation path between the motor's critical heat source windings and the end cap by introducing a heat spreader, significantly improving heat transfer efficiency. Specifically, a positioning boss is designed on the evaporation end of the heat spreader, achieving circumferential positioning while increasing the direct contact area with the heat source, thus improving heat conduction efficiency. Furthermore, annular fins are added to the outside of the heat dissipation end cap, and the slots between the fins are filled with heat-dissipating hydrogel material. The latent heat of phase change due to water evaporation in the hydrogel enables efficient heat dissipation from the end cap to the environment. Compared to traditional heat dissipation solutions, this invention provides an integrated thermal management solution that simultaneously addresses the two major thermal bottlenecks of rapid internal heat removal and efficient heat dissipation from the end cap. This solution is entirely based on passive heat dissipation principles, generating no additional energy consumption, featuring a compact structure and low space occupancy, providing reliable support for improving the power density and continuous operating performance of robot joint motors. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the joint motor structure of the present invention; Figure 2 This is a schematic diagram of the heat spreader of the present invention; Figure 3 This is a schematic diagram showing the assembly of the heat spreader, stator, and stator sealing shell of the present invention; Figure 4 This is a cross-sectional schematic diagram of the heat spreader, stator, and stator sealing shell of the present invention after assembly; Figure 5 This is a partial cross-sectional schematic diagram of the heat spreader, stator, and stator sealing shell of the present invention after being fitted together and filled with thermally conductive adhesive; Figure 6 This is a schematic diagram of the inner structure of the heat dissipation end cap of the present invention; Figure 7 This is a schematic diagram of the outer structure of the heat dissipation end cap of the present invention; Figure 8 This is a schematic diagram of the dustproof net structure of the present invention.

[0021] The following components are shown in the diagram: 1. Heat spreader plate; 2. Motor stator; 3. Stator sealing shell; 4. Motor rotor; 5. Heat dissipation end cover; 6. Motor housing; 7. Reducer; 8. Output end cover; 9. Hydrogel; 10. Dustproof mesh; 11. Annular boss at the condensing end of the heat spreader plate; 12. Boss at the evaporating end of the heat spreader plate; 13. Stator winding; 14. Thermally conductive adhesive; 15. Positioning groove; 16. Annular fins at the heat dissipation end cover; 17. Hydrogel filling groove; 18. Positioning hole of the dustproof mesh; 19. Dense mesh. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] A robot joint motor based on the synergistic heat dissipation of a heat spreader and hydrogel includes a heat spreader 1, a stator assembly, a rotor assembly, an evaporative cooling assembly, a motor housing 6, and an output end cap 8. One end of the motor housing 6 can be connected to an external robot joint via the output end cap 8, and the other end of the motor housing 6 is provided with and connected to the evaporative cooling assembly. An inner cavity is provided inside the motor housing 6, and the heat spreader 1, the stator assembly, and the rotor assembly are arranged coaxially within the inner cavity. The rotor assembly is located inside the stator assembly, with one end connected to the output end cap 8 and the other end fixed to the evaporative cooling assembly. One end of the stator assembly is in close contact with one end of the heat spreader 1, and the other end of the heat spreader 1 is connected to the evaporative cooling assembly.

[0024] Specifically, one end of the rotor assembly is located inside the stator assembly, and the stator assembly is connected to the evaporative cooling assembly through the heat spreader 1. The other end of the rotor assembly is located in a circular hole in the middle of the output end cover 8 and is connected to the external robot joint.

[0025] The evaporative heat dissipation component includes a hydrogel 9 for heat dissipation. The hydrogel 9 absorbs the heat generated by the joint motor stator and stator windings that are conducted through the heat spreader 1 to the heat dissipation end cover 5, and efficiently dissipates the heat to the surrounding environment through water evaporation.

[0026] Specifically, the heat generated by the stator and stator windings of the joint motor is conducted to the heat spreader 1, and then the heat is conducted by the heat spreader 1 to the evaporative heat dissipation component and absorbed by the hydrogel 9. The hydrogel 9 then efficiently dissipates the heat to the surrounding environment through water evaporation.

[0027] The heat spreader 1 adopts a near-ring-shaped structure. The heat spreader 1 includes a heat spreader ring, a heat spreader condensing end annular boss 11, and a heat spreader evaporating end boss 12. The two sides of the heat spreader ring are the heat spreader condensing end and the heat spreader evaporating end, respectively. A heat spreader condensing end annular boss 11 is provided on the end face of the heat spreader condensing end. The heat spreader condensing end annular boss 11 is coaxially arranged with the heat spreader ring and is smaller than the heat spreader ring. Multiple heat spreader evaporating end bosses 12 are provided on the heat spreader evaporating end. The heat spreader evaporating end bosses 12 are arranged at equal intervals along the circumference on the heat spreader evaporating end. The end of the heat spreader evaporating end boss 12 away from the heat spreader 1 is embedded in the stator assembly. The end of the heat spreader condensing end annular boss 11 away from the heat spreader 1 is connected to the heat dissipation end cover 5. The condensing end of the heat spreader is connected to the heat dissipation end cover 5, and the evaporating end of the heat spreader is connected to the stator assembly. The inner wall of the annular heat spreader 1 is spaced apart from the rotor assembly.

[0028] The stator assembly includes a motor stator 2, a stator sealing shell 3, a stator winding 13, a sealing plate, and thermally conductive adhesive 14; the motor stator 2 is mounted on the stator sealing shell 3 and connected to the heat spreader 1 through the motor stator 2.

[0029] The stator sealing shell 3 adopts a near-ring structure. The outer edge of the stator sealing shell 3 near the motor stator 2 is provided with a flange, and the inner edge is provided with multiple strip-shaped sealing plates arranged circumferentially and at equal intervals facing the motor stator 2. The diameter of the flange of the stator sealing shell 3 matches the diameter of the motor stator 2. The motor stator 2 is provided with multiple stator windings 13 arranged circumferentially and at equal intervals. The interval between every two stator windings 13 forms a stator slot. Each sealing plate and each heat spreader plate evaporation end boss 12 are embedded in a corresponding stator slot. The remaining space in the stator slot is filled with thermally conductive adhesive 14.

[0030] The number of sealing inserts, the evaporator end boss 12 of the heat spreader plate, the stator winding 13 and the stator slots are equal and their positions are matched. After the sealing inserts and the evaporator end boss 12 of the heat spreader plate are inserted into a stator slot, the evaporator end of the heat spreader plate is close to the end face of the stator winding 13 near the heat spreader plate 1, and the sealing inserts are in close contact with the stator winding 13. Each stator slot is enclosed by the motor housing 6, the motor stator 2, the stator winding 13, the sealing inserts and the heat spreader plate 1 to form a sealed stator cavity, and each stator cavity is filled with thermally conductive adhesive 14.

[0031] The motor stator 2 has multiple stator slots evenly distributed along the axial direction, and the stator sealing shell 3 has the same number of sealing plates evenly distributed along the circumferential direction as the stator slots. This allows the sealing plates to be fitted into the stator slot openings and seal together with other components. Then, thermally conductive adhesive 14 is filled into the stator slots. This achieves circumferential positioning of each component and increases the thermal contact area. The annular boss 11 at the condensation end of the heat spreader plate cooperates with the positioning groove 15 on the heat dissipation end cover 5 to achieve rapid heat conduction from the end of the stator winding 13 to the end cover 5.

[0032] Furthermore, the height of the evaporator end boss 12 of the heat spreader plate is 105% - 120% of the height of the winding end 13. The shape of the evaporator end boss 12 of the heat spreader plate is preferably a frustum, and the cross-sectional diameter of the evaporator end boss 11 of the heat spreader plate 1 is 90% - 95% of the diameter of the largest inscribed circle of the stator slot space. The purpose of adopting the above scheme is to ensure the positioning function of the boss and the effective thermal contact area, and to minimize the interference to the motor magnetic flux.

[0033] The evaporative heat dissipation assembly includes a heat dissipation end cap 5, hydrogel 9, and a dustproof net 10. One side of the heat dissipation end cap 5 is connected to the heat spreader 1 and the rotor assembly. The heat spreader 1 is located outside the rotor assembly. The other end of the heat dissipation end cap 5 is connected to the dustproof net 10. The gap between the heat dissipation end cap 5 and the dustproof net 10 is filled with hydrogel 9.

[0034] With the assistance of thermally conductive adhesive 14, the heat dissipation plate 1 quickly conducts the heat concentrated in the stator winding 13 to the heat dissipation end cover 5.

[0035] The side of the heat dissipation end cap 5 closest to the heat dissipation plate 1 is the inner side of the heat dissipation end cap, and the other side is the outer side of the heat dissipation end cap. The inner side of the heat dissipation end cap is recessed inward to form a positioning groove, which is used to connect with the annular boss 11 of the heat dissipation plate condensing end of the heat dissipation plate 1. The gap between the annular boss 11 of the heat dissipation plate condensing end and the positioning groove 15 is filled with thermally conductive adhesive.

[0036] Multiple coaxially arranged annular fins 16 are provided on the outer side of the heat dissipation end cap from the center outwards. A hydrogel filling groove 17 is formed between every two annular fins 16, and the hydrogel filling groove 17 is used to fill the hydrogel 9. The hydrogel 9 is embedded in the hydrogel filling groove 17, absorbs the heat conducted from the heat spreader 1 to the heat dissipation end cap 5, and efficiently dissipates the heat to the surrounding environment through water evaporation.

[0037] Multiple heat dissipation end cover positioning holes are provided on the outermost edge of the heat dissipation end cover annular fin 16. The corresponding position of the dustproof mesh 10 is provided with an equal number of dustproof mesh positioning holes 18. The dustproof mesh positioning holes 18 and the heat dissipation end cover positioning holes are matched one by one to fix the heat dissipation end cover 5 and the dustproof mesh 10.

[0038] The dustproof net 10 has multiple dense mesh holes 19. The dense mesh holes 19 are made of dense micropores. The dense mesh holes 19 are arranged in a radial concentric circle pattern from the inside to the outside with the center as the center. The overall distribution is uniform and symmetrical. The dense mesh holes 19 are used to allow the water in the hydrogel to diffuse smoothly into the air after evaporation, while avoiding pollution from dust and other particles.

[0039] The rotor assembly includes a motor rotor 4 and a reducer 7. The reducer 7 is arranged at intervals with the stator assembly. An output through hole is provided in the middle of the output end cover 8. The reducer 7 is arranged in the inner cavity of the housing and connected to the output end cover 8. One end of the reducer 7 near the output end cover 8 is set in the output through hole. The motor rotor 4 and the reducer 7 are fixedly connected. One end of the motor rotor 4 is connected to the outside through the reducer 7. The other end of the motor rotor 4 is set in the stator assembly and is in clearance fit with the stator winding 13 and the sealing plate in the stator assembly.

[0040] Hydrogel 9 is a PAM hydrogel, which was prepared using the following method: S1. Dissolve acrylamide monomer and crosslinking agent N,N'-methylenebisacrylamide in deionized water and stir thoroughly to form a precursor solution; S2. Add potassium persulfate as an initiator to the precursor solution and stir thoroughly under heating at 50°C. This allows the potassium persulfate to initiate a cross-linking reaction in the precursor solution itself. After the precursor solution solidifies through the cross-linking reaction, it forms a PAM hydrogel.

[0041] The mass ratio of acrylamide monomer, crosslinking agent N,N'-methylenebisacrylamide, and deionized water is 10:0.1:90~100; the mass ratio of potassium persulfate initiator to acrylamide monomer in the precursor solution is 1:100.

[0042] The robot's joint motor uses hydrogel 9 to absorb the heat generated in the stator of the joint motor, which is conducted to the heat dissipation end cover 5 via the heat spreader 1. The heat is then efficiently dissipated to the surrounding environment through water evaporation. The heat generated by the joint motor stator 2 and stator winding 13 is transferred to the heat spreader 1 with the assistance of thermally conductive adhesive 14 in the stator assembly. The heat spreader 1 quickly conducts heat out of the stator assembly. The condensation end of the heat spreader 1 fits tightly with the heat dissipation end cover 5 to transfer heat to the heat dissipation end cover 5. The heat is then absorbed by the hydrogel 9. After absorbing the heat, the hydrogel 9 utilizes the latent heat of phase change from water evaporation to efficiently dissipate the heat to the environment.

[0043] Specifically, the evaporation end of the heat spreader 1 is embedded in the stator slot through a designed boss, achieving circumferential positioning while closely adhering to the end of the stator winding 13, effectively increasing the heat exchange area and quickly dissipating the heat accumulated in the stator winding 13. The condensation end of the heat spreader 1 is tightly fitted with the heat dissipation end cover 5, realizing the transfer of heat to the heat dissipation end cover 5. The evaporative heat dissipation component is a heat dissipation end cover 5 embedded with hydrogel 9. The outer side of the heat dissipation end cover has a heat dissipation end cover annular fin structure 16 to expand the heat dissipation area, and the slots between the heat dissipation end cover annular fins 16 are filled with hydrogel 9. The hydrogel 9 absorbs the heat conducted from the heat spreader 1 to the heat dissipation end cover 5, and utilizes the latent heat of phase change of water evaporation to efficiently dissipate the heat into the environment. This invention achieves passive and efficient heat dissipation of the joint motor through the synergistic effect of the heat conduction of the heat spreader 1 and the evaporative heat dissipation of the hydrogel 9, with zero energy consumption and no additional space occupation.

[0044] like Figure 1 As shown, this invention proposes a robot joint motor based on the synergistic heat dissipation of a heat spreader and hydrogel, including a housing 6, an output end cap 8, a stator assembly, a rotor assembly, a heat spreader and heat conduction assembly, and an evaporative heat dissipation assembly. The stator assembly includes a motor stator 2 and a stator sealing shell 3, with the sealing shell 3 sealing one side of the motor stator 2. The stator assembly and housing 6 are interference-fitted. The rotor assembly includes a motor rotor 4 and a reducer 7, with one end of the reducer 7 fixed to the inside of the output end cap 8. The rotor assembly is coaxially disposed inside the motor stator 2. The heat spreader and heat conduction assembly is a heat spreader 1, fixed between the stator winding end 13 and the heat dissipation end cap 5, establishing a heat conduction path between the winding and the end cap. The evaporative heat dissipation assembly consists of a heat dissipation end cap 5 embedded with hydrogel 9 and a dustproof mesh 10. The hydrogel 9 is confined within the heat dissipation end cap by the dustproof mesh 10, achieving efficient heat dissipation through the evaporation of water in the hydrogel 9.

[0045] like Figure 2 As shown, the overall structure of the heat spreader 1 is designed as a ring, which allows it to be coaxially arranged inside the motor. This design fully utilizes the radial space and increases the thermal contact area without affecting the normal rotation of the motor rotor 4. The heat spreader 1 is generally made of copper with high thermal conductivity and has an evaporation end and a condensation end. Its interior is a vacuum-sealed cavity with a sintered capillary wick. During operation, the evaporation end absorbs heat, causing the liquid working fluid to evaporate and vaporize into steam. The generated steam rapidly diffuses to the low-temperature condensation end under the action of pressure difference, releases heat, and then re-condenses into liquid. Subsequently, the condensed liquid working fluid flows back to the evaporation end under the drive of capillary force, thus completing a closed self-circulation, achieving efficient heat transfer from the high-temperature region to the low-temperature region during the circulation.

[0046] Specifically, the evaporation end of the heat spreader 1 is used to absorb heat from the heat source winding. The evaporation end of the heat spreader 1 is tightly coupled to the end of the stator winding 13. Simultaneously, the evaporation end has the same number of heat spreader evaporation end bosses 12 as the stator slots. These bosses 12 can be precisely fitted into the corresponding stator slots filled with thermally conductive adhesive 14. This achieves the circumferential positioning of the heat spreader 1 in the motor and also expands the effective contact area between the heat source and the heat spreader 1, improving heat transfer efficiency. The annular boss 11 at the condensation end of the heat spreader 1 is used to transfer heat to the heat dissipation end cover 5. The annular boss 11 at the condensation end of the heat spreader 1 can cooperate with the positioning groove 15 on the heat dissipation end cover 5, ensuring that the annular boss 11 at the condensation end of the heat spreader 1 can fit tightly against the inner side of the heat dissipation end cover 5. This fixes the heat spreader 1 between the end of the critical heat source winding and the heat dissipation end cover 5, creating an additional heat conduction path to achieve rapid heat transfer from the inside of the motor to the end cover. The vapor chamber has an extremely high equivalent thermal conductivity and requires no external power, making it particularly suitable for heat dissipation scenarios with limited space and high heat flux density, such as inside robot joints.

[0047] Specifically, the height of the evaporator end boss 12 of the heat spreader plate is 105% - 120% of the stator winding height 13. This is to ensure that the evaporator end boss 12 can be embedded in the corresponding stator slot, while minimizing the generation of eddy currents in the heat spreader plate 1 that would cause additional heat loss and reduce the impact of the heat spreader plate 1 on the internal magnetic flux of the motor. The cross-sectional diameter of the evaporator end boss 12 is 90% - 95% of the maximum inscribed circle diameter of the stator slot space. This is to increase the heat exchange contact area between the heat spreader plate 1 and the heat source while achieving the positioning of the heat spreader plate 1, thereby improving thermal conductivity.

[0048] It should be noted that the cross-sectional shape of the evaporator end boss 12 of the heat spreader plate is generally preferably circular to facilitate processing and assembly. However, in actual implementation, its shape is not limited to this. The cross-sectional shape can be adaptively adjusted to a rectangle, rhombus, or other matching geometry according to the actual shape, size, and layout of the motor stator slot or specific heat dissipation requirements to ensure the positioning function of the boss and maximize effective contact with the heat source surface.

[0049] like Figure 3 As shown, the motor stator 2 has multiple stator slots evenly distributed circumferentially. Correspondingly, the stator sealing shell 3 has an equal number of sealing plates evenly distributed circumferentially. The stator sealing shell 3 and the motor stator 2 are assembled coaxially according to the method shown in the diagram, ensuring that the sealing plates are embedded in the openings of the stator slots, forming several stator slot spaces with only one end open. Each of these spaces is filled with a highly thermally conductive adhesive 14. Then, the same number of evaporating bosses 12 on the heat spreader 1 as the slot openings are inserted and assembled one by one, ensuring that the evaporating end of the heat spreader 1 is in close contact with the winding end 13.

[0050] It should be noted that the gap between the evaporation end of the heat spreader 1 and the stator winding 13 is filled with thermally conductive adhesive, and the gap between the annular boss 11 at the condensation end of the heat spreader and the positioning groove 15 at the heat dissipation end cover is filled with thermally conductive adhesive 14. The gaps between the heat spreader 1 and other components such as the motor housing 6 are also filled with thermally conductive adhesive 14.

[0051] like Figure 4 and Figure 5 As shown, each slot of the motor stator 2 is filled with thermally conductive adhesive 14, and each boss 12 of the evaporation end of the heat spreader plate is embedded in the corresponding stator slot filled with thermally conductive adhesive 14. The thermally conductive adhesive 14 absorbs the heat of the winding in the slot and conducts it to the boss 12 in the slot through contact, thereby realizing the positioning of the heat spreader plate 1, increasing the effective thermal contact area of ​​the heat spreader plate, and improving the heat conduction efficiency.

[0052] like Figure 6 and Figure 7 As shown, the heat dissipation end cap 5 has positioning holes and is connected to the motor housing 2 by screws. The inner side of the heat dissipation end cap 5 has a positioning groove 15 for positioning and fixing the condenser end 11 of the heat spreader. The outer side of the heat dissipation end cap has several concentric annular fins 13, which can increase the heat exchange area between the end cap 5 and the external environment. Multiple slots 14 are formed between the annular fins, and the slots are filled with the heat dissipation hydrogel 9. The hydrogel 9 absorbs the heat from the end cap, and the heat is diffused to the environment through the evaporation of water inside the hydrogel 9. To ensure the stable operation of the hydrogel, a dustproof net 10 is covered on the outside of the slots for fixation and physical protection.

[0053] Preferably, the hydrogel is a PAM hydrogel, and the hydrogel is prepared by the following method: S1. Dissolve the acrylamide monomer and crosslinking agent N,N'-methylenebisacrylamide in deionized water, place them in a container at room temperature and stir thoroughly until completely dissolved and mixed evenly to form a homogeneous and clear precursor solution.

[0054] S2. Add potassium persulfate as an initiator to the precursor solution and stir continuously under constant temperature heating at 50°C to allow the precursor solution to undergo cross-linking polymerization until the mixture solidifies to form a PAM hydrogel with a three-dimensional network structure.

[0055] Specifically, the mass ratio of the acrylamide monomer, the crosslinking agent N,N'-methylenebisacrylamide, and deionized water is 10:0.1:90~100. The mass ratio of the initiator potassium persulfate to the acrylamide monomer is 1:100.

[0056] It should be noted that the heat-dissipating hydrogel can be pre-molded into a geometric shape that matches the empty slot 14, so that it can be directly embedded between the annular fins 13 during subsequent assembly. The heat dissipation capacity of the hydrogel depends on the latent heat of phase change of the water vapor within it. After long-term operation, the heat dissipation performance will gradually decrease due to water loss. To address this, the present invention designs a maintainable structure: the dustproof mesh 10 is detachably connected to the heat dissipation end cap 5 by screws. When maintenance is required, the dustproof mesh 10 can be removed, and water can be sprayed directly onto the hydrogel 9 to replenish moisture. The operation is simple and quick, and can rapidly restore its evaporative heat dissipation performance. As an alternative, the failed hydrogel can also be completely removed and replaced with a new pre-molded hydrogel module, thus preparing for the next service cycle.

[0057] like Figure 8 As shown, the dustproof net 10 has a dense microporous structure. This structure allows water vapor from the hydrogel 9 to diffuse smoothly into the environment, while effectively blocking external dust and other pollutants from entering, maintaining the cleanliness and heat dissipation performance of the hydrogel 9. The dustproof net 10 has positioning holes 18 on its edge, which are detachably fastened to the heat dissipation end cap 5 by screws.

[0058] The above specific embodiments are used to explain the technical concept and features of the present invention, and are not intended to limit the present invention. Within the spirit and scope of protection of the present invention, that is, equivalent changes and improvements made in accordance with the scope of protection of the present invention and the content of the specification, should all fall within the scope of protection of the present invention.

Claims

1. A robot joint motor based on the synergistic heat dissipation of a heat spreader and hydrogel, characterized in that, The system includes a heat spreader (1), a stator assembly, a rotor assembly, an evaporative heat dissipation assembly, a motor housing (6), and an output end cap (8). One end of the motor housing (6) is connected to an external robot joint via the output end cap (8), and the other end of the motor housing (6) is provided with and connected to an evaporative heat dissipation assembly. An inner cavity is provided inside the motor housing (6), and a heat spreader (1), a stator assembly, and a rotor assembly are arranged coaxially within the inner cavity. The rotor assembly is located inside the stator assembly, with one end connected to the output end cap (8) and the other end connected to the evaporative heat dissipation assembly. One end of the stator assembly near the evaporative heat dissipation assembly is connected to one end of the heat spreader (1), and the other end of the heat spreader (1) is connected to the evaporative heat dissipation assembly. The evaporative heat dissipation assembly includes a hydrogel (9) for heat dissipation. The hydrogel (9) absorbs the heat generated by the robot joint that is conducted through the heat spreader (1) to the heat dissipation end cap (5) and efficiently dissipates the heat to the surrounding environment through water evaporation.

2. The robot joint motor based on the synergistic heat dissipation of a heat spreader and hydrogel according to claim 1, characterized in that, The heat spreader (1) adopts a ring-like structure. The heat spreader (1) includes a heat spreader ring, a heat spreader condensing end annular boss (11) and a heat spreader evaporating end boss (12). The two sides of the heat spreader ring are the heat spreader condensing end and the heat spreader evaporating end, respectively. A heat spreader condensing end annular boss (11) is provided on the end face of the heat spreader condensing end. The heat spreader condensing end annular boss (11) is coaxially arranged with the heat spreader ring. Multiple heat spreader evaporating end bosses (12) are provided on the heat spreader evaporating end. The heat spreader evaporating end bosses (12) are arranged at equal intervals along the circumference on the heat spreader evaporating end. The end of the heat spreader evaporating end boss (12) away from the heat spreader (1) is embedded in the stator assembly. The end of the heat spreader condensing end annular boss (11) away from the heat spreader (1) is connected to the heat dissipation end cover (5).

3. A robot joint motor based on synergistic heat dissipation of a heat spreader and hydrogel according to claim 2, characterized in that, The stator assembly includes a motor stator (2), a stator sealing shell (3), a stator winding (13), a sealing plate, and thermally conductive adhesive (14); the stator sealing shell (3) is provided with the motor stator (2) and is connected to the heat spreader (1) through the motor stator (2); The stator sealing shell (3) adopts a ring-like structure. The outer edge of the stator sealing shell (3) near the motor stator (2) is provided with a flange, and the inner edge is provided with a plurality of sealing inserts arranged circumferentially and at equal intervals facing the motor stator (2). The flange diameter of the stator sealing shell (3) matches the diameter of the motor stator (2). The motor stator (2) is provided with a plurality of stator windings (13) arranged circumferentially and at equal intervals. The interval between every two stator windings (13) forms a stator slot. Each sealing insert and each heat spreader plate evaporation end boss (12) is embedded in a corresponding stator slot. The remaining space in the stator slot is filled with thermally conductive adhesive (14).

4. A robot joint motor based on synergistic heat dissipation of a heat spreader and hydrogel according to claim 2, characterized in that, The number of sealing inserts, heat spreader plate evaporation end bosses (12), stator windings (13) and stator slots are equal and their positions are matched. After the sealing inserts and heat spreader plate evaporation end bosses (12) are inserted into a stator slot, the heat spreader plate evaporation end is close to the end face of the stator winding (13) near the heat spreader plate (1), and the sealing inserts are in close contact with the stator winding (13). Each stator slot is enclosed by the motor housing (6), motor stator (2), stator windings (13), sealing inserts and heat spreader plate (1) to form a closed stator cavity, and each stator cavity is filled with thermally conductive adhesive (14).

5. A robot joint motor based on synergistic heat dissipation of a heat spreader and hydrogel according to claim 2, characterized in that, The evaporative heat dissipation assembly includes a heat dissipation end cap (5), hydrogel (9) and a dustproof net (10). One side of the heat dissipation end cap (5) is connected to the heat spreader (1) and the rotor assembly, and the other end of the heat dissipation end cap (5) is connected to the dustproof net (10). The gap between the heat dissipation end cap (5) and the dustproof net (10) is filled with hydrogel (9).

6. A robot joint motor based on synergistic heat dissipation of a heat spreader and hydrogel according to claim 5, characterized in that, The heat dissipation end cap (5) has an inner side near the heat spreader plate (1) and an outer side near the heat dissipation end cap (5). The inner side of the heat dissipation end cap is recessed inward to form a positioning groove. The positioning groove is used to connect with the annular boss (11) of the heat spreader plate condensing end of the heat spreader plate (1) with a gap. The gap between the annular boss (11) of the heat spreader plate condensing end and the positioning groove (15) is filled with thermally conductive adhesive. The outer side of the heat dissipation end cap is provided with a plurality of coaxially arranged annular heat dissipation end cap fins (16) from the center outward. A hydrogel filling groove (17) is formed between every two heat dissipation end cap annular fins (16), and the hydrogel filling groove (17) is used to fill hydrogel (9).

7. A robot joint motor based on synergistic heat dissipation of a heat spreader and hydrogel according to claim 5, characterized in that, The dustproof net (10) has multiple dense mesh holes (19). The dense mesh holes (19) are arranged in a radial concentric circle pattern from the inside to the outside, with the center as the center. The dense mesh holes (19) are used to allow the water in the hydrogel to evaporate and diffuse into the air.

8. A robot joint motor based on synergistic heat dissipation of a heat spreader and hydrogel according to claim 2, characterized in that, The rotor assembly includes a motor rotor (4) and a reducer (7). The reducer (7) is arranged at intervals with the stator assembly. The output end cover (8) has an output through hole in the middle. The reducer (7) is arranged in the inner cavity of the housing and connected to the output end cover (8). One end of the reducer (7) near the output end cover (8) is set in the output through hole. The motor rotor (4) and the reducer (7) are fixedly connected. One end of the motor rotor (4) is connected to the outside through the reducer (7). The other end of the motor rotor (4) is set in the stator assembly and is in clearance fit with the stator winding (13) and the sealing plate in the stator assembly.

9. A robot joint motor based on synergistic heat dissipation of a heat spreader and hydrogel according to claim 5, characterized in that, The hydrogel (9) is a PAM hydrogel, which is prepared by the following method: S1. Dissolve acrylamide monomer and crosslinking agent N,N'-methylenebisacrylamide in deionized water and stir thoroughly to form a precursor solution; S2. Add potassium persulfate as an initiator to the precursor solution and stir thoroughly under heating at 50°C, so that the potassium persulfate initiator initiates the cross-linking reaction of the precursor solution itself. After the precursor solution is cured by the cross-linking reaction, a PAM hydrogel is formed.

10. A robot joint motor based on heat dissipation through a heat spreader and hydrogel as described in claim 9, characterized in that: The mass ratio of the acrylamide monomer, the crosslinking agent N,N'-methylenebisacrylamide, and deionized water is 10:0.1:90~100; the mass ratio of the initiator potassium persulfate to the acrylamide monomer in the precursor solution is 1:100.

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