Frameless motor based on porous hydrogel and heat dissipation method thereof

Abstract

The invention discloses a frameless motor based on porous hydrogel and a heat dissipation method thereof. The front sealing shell and the rear sealing shell are installed at the front end and the rear end of the motor stator respectively, the front sealing shell, the motor stator and the rear sealing shell are all in an annular shape, the motor rotor is arranged on the inner side of the motor stator, the front sealing shell and one end of the motor stator are embedded in a matched mode to form a plurality of axially-distributed groove positions, and hot-end hydrogel is arranged in the groove positions. The rear sealing shell is embedded into the other end of the motor stator, annular cold-end hydrogel is arranged at the position, close to the rear end of the motor stator, in the rear sealing shell, the cold-end hydrogel makes contact with the hot-end hydrogel, and the annular inner side and the annular outer side of the cold-end hydrogel are provided with an inner side graphene heat conduction band and an outer side graphene heat conduction band respectively; cavities are formed in the hot-end hydrogel and the cold-end hydrogel and are communicated with each other, and cooling liquid is filled in the cavities. According to the heat dissipation scheme, the structure is simple, integration is convenient, the capillary structure tightly attached to the heat source of the motor is manufactured through the hydrogel, the heat conductivity of the porous hydrogel is high, and the preparation method is simple.

Description

Technical Field

[0001] The present invention relates to the technical field of frameless motors, and in particular to a frameless motor based on porous hydrogel and a heat dissipation method thereof. Background Art

[0002] With the continuous development of embodied intelligence technology, humanoid robots, as the next generation of computing terminals after PCs, smart phones and new energy vehicles, have become an important carrier of embodied intelligence technology due to their high flexibility and movement patterns similar to humans. In particular, they have shown great potential in intelligent manufacturing, medical assistance, and housekeeping services, and are gradually becoming a disruptive industry with broad market application prospects.

[0003] In the design of humanoid robots, the joint drive system is the core part to achieve its flexible movement. Frameless motors have become the preferred power source for driving the joint movement of humanoid robots due to their high efficiency, compactness and high integration. However, despite the many advantages of frameless motors, thermal management during their operation is still an important challenge, especially in scenarios with high loads and long-term operation, where the impact of heat loss on motor performance cannot be ignored.

[0004] During the operation of the frameless motor, the eddy current effect and the Joule effect will cause heat accumulation, resulting in an increase in the temperature of the stator and rotor, which in turn reduces the output torque and power of the motor. In addition, the winding resistance increases with the temperature, further increasing the Joule heat loss, significantly reducing the overall efficiency of the motor and reducing energy utilization. Under long-term high-temperature operation conditions, the insulation material of the winding will gradually age, increasing the risk of internal short circuits in the motor. The mechanical properties of the rotor and stator materials will also decrease at high temperatures, resulting in weakened structural strength and prone to mechanical failure. Especially in high-dynamic response humanoid robot joint applications, the motor is often in a state of frequent starting, stopping and acceleration. This thermal fatigue effect may accelerate the aging process of the motor. Therefore, it is crucial to solve the heat loss problem of frameless motors.

[0005] Among the current cooling solutions for frameless motors, air cooling often increases the overall size and weight of the motor due to the installation of fans, and liquid cooling requires the design of multiple coolant circulation channels. When the number of motors in the drive system is large, the power consumption of the coolant pump and the complexity of the system will be greatly increased. Humanoid robots often have multiple joint modules, so the above methods are not conducive to the application of frameless motors in humanoid robots. In order to maintain the stability of frameless motors during long-term operation, it is urgent to develop a compact, simple, efficient, and easy-to-integrate cooling solution to solve the heat loss problem. Summary of the invention

[0006] In order to solve the problems of severe heat loss, severe thermal fatigue, and complex heat dissipation system during the operation of a frameless motor, the purpose of the present invention is to provide a frameless motor based on porous hydrogel and a heat dissipation method thereof. A porous hydrogel close to the winding is prepared inside the motor by a simple method, and the circulation of the coolant between the motor winding and the rear sealing shell is achieved through the capillary force of the porous hydrogel and the phase change principle of the coolant. The heat is then conducted to the cooling device through a graphene heat conductive belt in the rear sealing shell, thereby achieving efficient heat dissipation.

[0007] The technical solution adopted by the present invention is:

[0008] The present invention comprises a front sealing shell, a hot end hydrogel, a motor rotor, a motor stator, an inner graphene heat conducting belt, a cold end hydrogel, an outer graphene heat conducting belt and a rear sealing shell;

[0009] The front end and rear end of the motor stator are respectively installed with a front sealing shell and a rear sealing shell, the front sealing shell, the motor stator and the rear sealing shell are all annular, the motor rotor is coaxially arranged on the inner side of the motor stator, the front sealing shell is matched and embedded with one end of the motor stator to form a plurality of axially distributed slots, each of which is provided with a hot end hydrogel, the rear sealing shell is matched and embedded with the other end of the motor stator, and an annular cold end hydrogel is provided in the rear sealing shell near the rear end of the motor stator, the cold end hydrogel is in contact with the hot end hydrogel, and the inner and outer sides of the annular cold end hydrogel are respectively provided with an inner graphene heat conducting belt and an outer graphene heat conducting belt;

[0010] Each hot-end hydrogel is provided with a cavity structure as the hot-end hydrogel inner cavity, and the cold-end hydrogel is provided with several cavity structures, one cavity structure being used as the cold-end hydrogel inner cavity. The hot-end hydrogel inner cavity and the cold-end hydrogel inner cavity are interconnected to form a heat dissipation cavity and are filled with cooling liquid.

[0011] The motor stator comprises a stator core and a winding, wherein a plurality of stator slots are evenly distributed along the circumferential direction on the inner side of the stator core, and the winding is wound on the teeth between the stator slots of the stator core. A plurality of sealing plugs pointing to the rear sealing shell are evenly distributed along the circumferential direction on the inner side of the front sealing shell, and the sealing plugs are embedded in the notches of the stator slots and seal the notches so that a slot for installing the hot end hydrogel is formed in the stator slots.

[0012] A cavity structure is provided at a position directly opposite to the cavity structure on the cold end hydrogel and each hot end hydrogel as a cold end hydrogel inner cavity. A cold end hydrogel inner cavity and a hot end hydrogel inner cavity are interconnected to form a heat dissipation cavity with cooling liquid inside.

[0013] The inner circumferential surface of the cold end hydrogel ring is in close contact with the inner graphene thermal conductive belt, the front end surface of the cold end hydrogel is in close contact with the hot end hydrogel in the slot of the motor stator, the outer circumferential surface and the rear end surface of the cold end hydrogel ring are in close contact with the outer graphene thermal conductive belt, and the inner graphene thermal conductive belt, the cold end hydrogel, and the outer graphene thermal conductive belt are covered by the rear sealing shell and are sealed and connected to the rear end surface of the motor stator.

[0014] The side wall of the rear sealing shell is provided with an opening, through which the inner graphene heat conducting belt and the outer graphene heat conducting belt extend outward and merge, and the extended part serves as the outward extension end of the graphene heat conducting belt and fits with the external radiator.

[0015] The frameless motor is in an annular shape as a whole, and the motor rotor is connected to the output shaft along a direction pointing toward the front sealing shell or the rear sealing shell.

[0016] The hot end hydrogel and the cold end hydrogel are both porous hydrogels, and the porous hydrogels are prepared by the following method:

[0017] S1, adding polyvinyl alcohol into water and stirring to obtain a hydrogel precursor;

[0018] S2. Adding nano copper particles to a hydrogel precursor, inserting an ultrasonic disperser into the hydrogel precursor for vibration, and obtaining a solidified hydrogel as a porous hydrogel.

[0019] The mass ratio of the polyvinyl alcohol to water is 1:5-10.

[0020] The nano copper particles are nano copper particles with a particle size of 60 to 100 nm, and the mass ratio of the nano copper particles to the hydrogel precursor is 1:7 to 9.

[0021] When the frameless motor is working, the temperature of the motor stator rises, and the coolant in the hot-end hydrogel absorbs heat and vaporizes to become hot steam after being heated, and then enters the cavity inside the hot-end hydrogel. The hot steam flows from the cavity inside the hot-end hydrogel to the cavity inside the cold-end hydrogel under the action of internal air pressure. The temperature of the cold-end hydrogel is relatively low, and the hot steam is cooled and liquefied into condensate in the cavity inside the cold-end hydrogel, and releases the absorbed heat. The cold-end hydrogel absorbs heat and transfers the heat to the external radiator through the inner graphene thermal tape and the outer graphene thermal tape. The condensate is absorbed by the cold-end hydrogel and flows back to the hot-end hydrogel from the cold-end hydrogel under the action of the capillary force of the porous hydrogel, thereby achieving heat dissipation in this reciprocating cycle.

[0022] The beneficial effects of the present invention are:

[0023] 1) The manufacture of a capillary structure close to the heat source of the motor is achieved through hydrogel. The heat generated by the motor is mainly in the winding, which is made of multiple coils with an uneven surface, so the gap structure between each winding is irregular. If a capillary heat pipe is directly used to fill the windings, on the one hand, it is impossible to achieve a close fit between the surface of the heat pipe and the coil, and on the other hand, there is excess thermal resistance in the sealing material outside the heat pipe, which greatly reduces the heat dissipation efficiency; if a capillary structure is directly manufactured between the windings, the current industrial field mostly uses the copper powder sintering method to manufacture capillary structures. The high temperature during the sintering process will damage the motor. Therefore, the use of hydrogel to manufacture the capillary structure between the windings not only achieves a close fit between the capillary structure and the winding, but also avoids damage to the motor during the manufacturing process.

[0024] 2) The thermal conductivity of porous hydrogel is high and the preparation method is simple. The currently widely used method for manufacturing porous hydrogel is usually to place the hydrogel in a vacuum device, and to extract the bubbles in the gel by negative pressure during the curing process to achieve the manufacture of internal pores. However, this method has a slow curing speed, cumbersome steps, and it is difficult to manufacture cavities for gas flow in porous hydrogels. The ultrasonic vibration copper particle method proposed in the present invention can achieve rapid manufacture of micropores, and the heat generated by ultrasonic vibration will accelerate the evaporation of water in the hydrogel and accelerate the curing speed. In addition, a large number of nano copper particles are distributed in the porous hydrogel, which can improve the thermal conductivity of the hydrogel.

[0025] 3) The heat dissipation scheme proposed in the present invention has a simple structure and is easy to manufacture and integrate. When there are multiple motors in a drive system that need to dissipate heat, air cooling often increases the overall volume and weight due to the installation of fans, and liquid cooling requires the design of multiple coolant circulation channels, which increases the power consumption of the pump and makes the system complex. These methods are not conducive to the application of frameless motors in humanoid robots. However, this heat dissipation scheme uses graphene heat conducting belts to extract heat from the motor. In a system with multiple motors, it is only necessary to connect the graphene heat conducting belts to the same radiator to achieve synchronous cooling of multiple motors. The system is simple and reliable and ensures high heat dissipation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is an overall isometric view of the present invention.

[0027] Figure 2 It is a three-dimensional exploded schematic diagram of the present invention.

[0028] Figure 3 It is a cross-sectional view of the motor stator of the present invention.

[0029] Figure 4 It is an assembly diagram of the front sealing cover and the motor stator core of the present invention.

[0030] Figure 5 It is a cross-sectional view of the rear end cover of the present invention.

[0031] Figure 6 It is a schematic diagram of the heat dissipation principle of the porous hydrogel of the present invention.

[0032] Figure 7 It is a schematic diagram of the steps for preparing the hot end hydrogel of the present invention.

[0033] Figure 8 It is a schematic diagram corresponding to the hot-end hydrogel and the cold-end hydrogel cavities of the present invention.

[0034] In the figure: 1. Extended end of graphene heat-conducting belt; 2. Front sealing shell; 3. Hot-end hydrogel; 4. Motor rotor; 5. Motor stator; 6. Inner graphene heat-conducting belt; 7. Cold-end hydrogel; 8. Outer graphene heat-conducting belt; 9. Rear sealing shell; 10. Stator core; 11. Winding; 12. Hot-end hydrogel inner cavity; 13. Sealing plug plate; 14. Cold-end hydrogel inner cavity. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0036] A frameless motor based on porous hydrogel Figure 2 and Figure 3 As shown, it includes a front sealing shell 2, a hot end hydrogel 3, a motor rotor 4, a motor stator 5, an inner graphene heat conducting belt 6, a cold end hydrogel 7, an outer graphene heat conducting belt 8 and a rear sealing shell 9;

[0037] The front and rear ends of the motor stator 5 are respectively installed with a front sealing shell 2 and a rear sealing shell 9. The front sealing shell 2, the motor stator 5 and the rear sealing shell 9 are all annular. The front sealing shell, the motor stator and the rear sealing shell form a closed chamber, which is sealed with sealant. The chamber is filled with porous hydrogel and coolant. The motor rotor 4 is coaxially arranged on the inner side of the motor stator 5. The front sealing shell 2 and one end of the motor stator 5 are fitted together to form a number of axially distributed slots. A hot end hydrogel 3 is arranged inside each slot. The rear sealing shell 9 is fitted together with the other end of the motor stator 5. An annular cold end hydrogel 7 is arranged in the rear sealing shell 9 near the rear end of the motor stator 5. The cold end hydrogel 7 is in contact with the hot end hydrogel 3 in all the slots of the motor stator 5. The inner and outer sides of the annular cold end hydrogel 7 are respectively provided with an inner graphene heat conducting belt 6 and an outer graphene heat conducting belt 8.

[0038] like Figure 8 As shown, each hot-end hydrogel 3 is provided with a cavity structure as the hot-end hydrogel inner cavity 12, and the cold-end hydrogel 7 is provided with a plurality of cavity structures, one cavity structure being used as a cold-end hydrogel inner cavity 14. The hot-end hydrogel inner cavity 12 and the cold-end hydrogel inner cavity are connected to each other to form a heat dissipation cavity which is sealed and filled with cooling liquid.

[0039] like Figure 3 and 4 As shown, the motor stator 5 includes a stator core 10 and a winding 11. A plurality of stator slots are evenly spaced along the circumferential direction on the inner side of the stator core 10. The winding 11 is wound on the teeth between the stator slots of the stator core 10. A plurality of sealing inserts 13 pointing to the rear sealing shell 9 are evenly spaced along the circumferential direction on the inner side of the front sealing shell 2. The sealing inserts 13 are embedded in the notches of the stator slots and seal the notches so that slots for installing the hot end hydrogel 3 and the winding 11 are formed in the stator slots.

[0040] A cavity structure is provided at the position opposite to the cavity structure on the cold-end hydrogel 7 and each hot-end hydrogel 3 as a cold-end hydrogel inner cavity 14. A cold-end hydrogel inner cavity 14 and a hot-end hydrogel inner cavity 12 are connected to each other to form a heat dissipation cavity which is sealed and filled with coolant.

[0041] like Figure 5 As shown, the annular inner circumferential surface of the cold end hydrogel 7 is in close contact with the inner graphene thermal conductive belt 6, the front end surface of the cold end hydrogel 7 is in close contact with the hot end hydrogel 3 in the slot of the motor stator 5, the annular outer circumferential surface and the rear end surface of the cold end hydrogel 7 are in close contact with the outer graphene thermal conductive belt 8, and the inner graphene thermal conductive belt 6, the cold end hydrogel 7, and the outer graphene thermal conductive belt 8 are covered by the rear sealing shell 9 and are sealed and connected to the rear end surface of the motor stator 5.

[0042] An opening is provided on the side wall of the rear sealing shell 9, through which the inner graphene heat conducting belt 6 and the outer graphene heat conducting belt 8 extend outward and merge, and the extended portion serves as the graphene heat conducting belt extension end 1 and fits with the external heat sink.

[0043] like Figure 1 As shown, the frameless motor is annular as a whole, and the motor rotor 4 is connected to the output shaft in a direction pointing toward the front sealing shell 2 or the rear sealing shell 9. The heat dissipation solution is integrated inside the motor, and no additional housing is required.

[0044] Both the hot-end hydrogel 3 and the cold-end hydrogel 7 are porous hydrogels, and the porous hydrogels are prepared by the following method:

[0045] S1, adding polyvinyl alcohol into water and stirring to obtain a hydrogel precursor;

[0046] S2. Add nano copper particles to the hydrogel precursor, insert a columnar ultrasonic disperser into the hydrogel precursor and vertically fix it in the middle of every two windings to vibrate, and obtain a solidified hydrogel as a porous hydrogel.

[0047] The ultrasonic disperser emits sound waves to produce cavitation effect, causing the nano-copper particles to vibrate at high frequency, thereby forming a large number of pores during the hydrogel curing process; at the same time, the heat generated by cavitation during the ultrasonic dispersion process accelerates the evaporation of water in the hydrogel, thereby accelerating the curing of the hydrogel. The large number of distributed nano-copper particles can improve the thermal conductivity of the hydrogel.

[0048] The hydrogel precursor is a hydrogel in a liquid state.

[0049] The mass ratio of polyvinyl alcohol to water is 1:5-10.

[0050] The nano copper particles are nano copper particles with a particle size of 60 to 100 nm, and the mass ratio of the nano copper particles to the hydrogel precursor is 1:7 to 9.

[0051] The hot-end hydrogel 3 and the cold-end hydrogel 7 are both porous hydrogels. The hot-end hydrogel 3 is heated by contact with the winding 11 and is therefore called the hot-end hydrogel 3. The cold-end hydrogel 7 is cooled by the inner graphene heat conducting belt 6 and the outer graphene heat conducting belt 8 and is attached to the external radiator and is therefore called the cold-end hydrogel 7.

[0052] like Figure 6 As shown, when the frameless motor is working, the coolant inside the cavity of the hot end hydrogel 3 is heated and circulates in the hot end hydrogel 3, the cold end hydrogel 7 and the heat dissipation cavity to achieve efficient heat dissipation of the motor.

[0053] Specifically, when the frameless motor is working, the temperature of the motor stator 5 rises, and the coolant in the hot-end hydrogel 3 absorbs heat and vaporizes to become hot steam after being heated, and then enters the hot-end hydrogel inner cavity 12. The hot steam flows from the hot-end hydrogel inner cavity 12 to the cold-end hydrogel inner cavity 14 under the action of internal air pressure. Since the temperature of the cold-end hydrogel 7 is relatively low, the hot steam is cooled and liquefied into condensate in the cold-end hydrogel inner cavity 14, and releases the absorbed heat. The cold-end hydrogel 7 absorbs the heat and transfers the heat to the external radiator through the inner graphene thermal conductive belt 6 and the outer graphene thermal conductive belt 8. The condensate is absorbed by the cold-end hydrogel 7 and flows back to the hot-end hydrogel 3 from the cold-end hydrogel 7 under the action of the capillary force of the porous hydrogel, thereby achieving efficient heat dissipation through a reciprocating cycle.

[0054] Through the capillary force of porous hydrogel and the phase change principle of coolant, the coolant circulates between the motor winding and the rear sealing shell, and the heat is transferred to the cooling device through the graphene heat conducting belt in the rear sealing shell, thereby achieving efficient heat dissipation. The heat conduction process of the heat dissipation scheme is as follows: the hot end, i.e. the motor stator, transfers the heat to the coolant in the hydrogel, and the coolant transfers the heat to the cold end, i.e. the rear sealing shell, through the phase change cycle, and then the inner and outer graphene heat conducting belts of the rear sealing shell transfer the heat to the external radiator. Among them, the rear sealing shell is connected to the external radiator through the graphene heat conducting belt, so the temperature is lower than that of the motor stator, and the temperature difference drives the phase change cycle of the coolant.

[0055] The manufacturing process of frameless motor includes the following steps: Figure 7 As shown,

[0056] S1, fitting the front sealing shell 2 and the motor stator 5 together to form a plurality of axially distributed slots;

[0057] S2, injecting the hydrogel precursor doped with nano copper particles into each slot respectively through a syringe, and due to its liquid fluidity, the hydrogel precursor can be closely attached to the irregular surface of the winding 11 on the motor stator 5 after standing for a period of time, and then inserting a columnar ultrasonic disperser into the hydrogel precursor in each slot, and all columnar ultrasonic dispersers vibrate at the same time, and the nano copper particles vibrate at a high frequency through the cavitation effect generated by the ultrasonic wave, so as to form a large number of pores during the hydrogel curing process, and stop vibrating after the hydrogel precursor is cured, and take out the columnar ultrasonic disperser, and form a hot-end hydrogel inner cavity 12 at the position of the original columnar ultrasonic disperser, so as to obtain a hot-end hydrogel 3 having a hot-end hydrogel inner cavity 12 and a front sealing shell 2 and a motor stator 5 containing the hot-end hydrogel 3;

[0058] S3, assembling the rear sealing shell 9, the inner graphene heat conducting belt 6 and the outer graphene heat conducting belt 8 to form an annular cavity;

[0059] S4, injecting a hydrogel precursor doped with nano-copper particles into the annular cavity through a syringe, then inserting a plurality of columnar ultrasonic dispersers into the hydrogel precursor in the annular cavity, vibrating all the columnar ultrasonic dispersers simultaneously, stopping the vibration after the hydrogel precursor is solidified, taking out the columnar ultrasonic dispersers, forming a cold-end hydrogel inner cavity 14 at the location of the original columnar ultrasonic dispersers, and obtaining a cold-end hydrogel 7 having a cold-end hydrogel inner cavity 14 and a rear sealing shell 9 containing the cold-end hydrogel 7;

[0060] The number of cylindrical ultrasonic dispersers depends on the number of motor windings.

[0061] S5, adding an appropriate amount of cooling liquid into the hot-end hydrogel inner cavity 12 of the hot-end hydrogel 3 and the cold-end hydrogel inner cavity 14 of the cold-end hydrogel 7, and the cooling liquid is absorbed by the hot-end hydrogel 3 and the cold-end hydrogel 7;

[0062] S6, sequentially assembling the front sealing shell 2 containing the hot end hydrogel 3, the motor stator 5, the motor rotor 4 and the rear sealing shell 9 containing the cold end hydrogel 7 to obtain a frameless motor.

[0063] The winding is formed by winding multiple turns of wire, and the surface is uneven with tiny gaps between the wires. However, due to the liquid fluidity of the hydrogel precursor, it can fit tightly with the irregular surface of the winding 11.

[0064] S4 is specifically as follows: injecting the hydrogel precursor doped with nano-copper particles into the annular cavity through a syringe, then inserting a columnar ultrasonic disperser into the position corresponding to each hot-end hydrogel inner cavity 12 in the hydrogel precursor of the annular cavity, all columnar ultrasonic dispersers vibrate at the same time, and stop vibrating after the hydrogel precursor is solidified, and taking out the columnar ultrasonic disperser to obtain the cold-end hydrogel 7 having the cold-end hydrogel inner cavity 14. The distribution position of the columnar ultrasonic dispersers is the same as that when preparing the cold-end hydrogel, so that the hot-end hydrogel inner cavity 12 and the cold-end hydrogel inner cavity 14 are connected to each other after the preparation.

[0065] The hot-end hydrogel precursor is filled between the motor windings. During the hydrogel curing process, the nano-copper particles inside are vibrated at high frequency to form a large number of pores, thereby realizing the preparation of porous hydrogels that are closely attached to the windings.

[0066] The frameless motor using the heat dissipation solution of the present invention is compact and suitable for a drive system where multiple motors work simultaneously. It only needs to connect the extended end 1 of the graphene heat conducting belt of each motor to an external radiator to achieve efficient cooling of multiple motors simultaneously. Other heat dissipation methods using air cooling and liquid cooling will generate extra volume, consume more power and have a complex system, which is disadvantageous for the application of humanoid robots.

[0067] The above specific implementation modes are used to explain the present invention rather than to limit the present invention. Within the spirit of the present invention and the protection scope of the claims, that is, equivalent changes and modifications made according to the protection scope of the present invention and the contents of the specification should fall within the protection scope of the present invention.

Claims

1. A frameless motor based on porous hydrogel, characterized in that: It comprises a front sealing shell (2), a hot end hydrogel (3), a motor rotor (4), a motor stator (5), an inner graphene heat conducting belt (6), a cold end hydrogel (7), an outer graphene heat conducting belt (8) and a rear sealing shell (9); The front and rear ends of the motor stator (5) are respectively provided with a front sealing shell (2) and a rear sealing shell (9); the front sealing shell (2), the motor stator (5) and the rear sealing shell (9) are all annular; the motor rotor (4) is coaxially arranged on the inner side of the motor stator (5); the front sealing shell (2) and one end of the motor stator (5) are fitted together to form a plurality of axially distributed slots; a hot end hydrogel (3) is provided inside each slot; the rear sealing shell (9) and the other end of the motor stator (5) are fitted together; an annular cold end hydrogel (7) is provided inside the rear sealing shell (9) near the rear end of the motor stator (5); the cold end hydrogel (7) and the hot end hydrogel (3) are in contact; an inner graphene heat conducting belt (6) and an outer graphene heat conducting belt (8) are respectively provided on the inner and outer sides of the annular cold end hydrogel (7); Each hot-end hydrogel (3) is provided with a cavity structure as a hot-end hydrogel inner cavity (12), and the cold-end hydrogel (7) is provided with a plurality of cavity structures, one cavity structure being a cold-end hydrogel inner cavity (14). The hot-end hydrogel inner cavity (12) and the cold-end hydrogel inner cavity are interconnected to form a heat dissipation cavity and a cooling liquid is contained therein.

2. A frameless motor based on porous hydrogel according to claim 1, characterized in that: The motor stator (5) comprises a stator core (10) and a winding (11), wherein a plurality of stator slots are evenly spaced along the circumferential direction on the inner side of the stator core (10), and the winding (11) is wound on teeth between the stator slots of the stator core (10). A plurality of sealing inserts (13) pointing to the rear sealing shell (9) are evenly spaced along the circumferential direction on the inner side of the front sealing shell (2), and the sealing inserts (13) are embedded in the notches of the stator slots and seal the notches so that a slot for installing the hot end hydrogel (3) is formed in the stator slots.

3. A frameless motor based on porous hydrogel according to claim 2, characterized in that: A cavity structure is provided at a position directly opposite to the cavity structure on the cold-end hydrogel (7) and each hot-end hydrogel (3) as a cold-end hydrogel inner cavity (14); a cold-end hydrogel inner cavity (14) and a hot-end hydrogel inner cavity (12) are interconnected to form a heat dissipation cavity and a cooling liquid is contained therein.

4. The porous hydrogel-based frameless motor according to claim 1, characterized in that: The annular inner circumferential surface of the cold end hydrogel (7) is in close contact with the inner graphene heat conductive belt (6), the front end surface of the cold end hydrogel (7) is in close contact with the hot end hydrogel (3) in the slot of the motor stator (5), the annular outer circumferential surface and the rear end surface of the cold end hydrogel (7) are in close contact with the outer graphene heat conductive belt (8), and the inner graphene heat conductive belt (6), the cold end hydrogel (7), and the outer graphene heat conductive belt (8) are covered by a rear sealing shell (9) and are sealed and connected to the rear end surface of the motor stator (5).

5. The porous hydrogel-based frameless motor according to claim 1, characterized in that: The side wall of the rear sealing shell (9) is provided with an opening, and the inner graphene heat conducting belt (6) and the outer graphene heat conducting belt (8) extend outward through the opening and merge, and the extended portion serves as the graphene heat conducting belt extension end (1) and fits with the external heat sink.

6. The porous hydrogel-based frameless motor according to claim 1, characterized in that: The frameless motor is annular as a whole, and the motor rotor (4) is connected to the output shaft in a direction pointing toward the front sealing shell (2) or the rear sealing shell (9).

7. The porous hydrogel-based frameless motor according to claim 1, characterized in that: The hot end hydrogel (3) and the cold end hydrogel (7) are both porous hydrogels, and the porous hydrogels are prepared by the following method: S1, adding polyvinyl alcohol into water and stirring to obtain a hydrogel precursor; S2. Adding nano copper particles to a hydrogel precursor, inserting an ultrasonic disperser into the hydrogel precursor for vibration, and obtaining a solidified hydrogel as a porous hydrogel.

8. The porous hydrogel-based frameless motor according to claim 6, characterized in that: The mass ratio of the polyvinyl alcohol to water is 1:5-10.

9. The porous hydrogel-based frameless motor according to claim 6, characterized in that: The nano copper particles are nano copper particles with a particle size of 60 to 100 nm, and the mass ratio of the nano copper particles to the hydrogel precursor is 1:7 to 9.

10. The heat dissipation method applied to the frameless motor according to any one of claims 1 to 9, characterized in that: When the frameless motor is working, the temperature of the motor stator (5) rises, and the cooling liquid in the hot-end hydrogel (3) absorbs heat and vaporizes to become hot steam after being heated, and then enters the hot-end hydrogel inner cavity (12). The hot steam flows from the hot-end hydrogel inner cavity (12) to the cold-end hydrogel inner cavity (14) under the action of internal air pressure. The cold-end hydrogel (7) has a lower temperature, and the hot steam is cooled and liquefied into condensate in the cold-end hydrogel inner cavity (14), and releases the absorbed heat. The cold-end hydrogel (7) absorbs the heat and transfers the heat to the external radiator through the inner graphene heat conducting belt (6) and the outer graphene heat conducting belt (8). The condensate is absorbed by the cold-end hydrogel (7) and flows back to the hot-end hydrogel (3) under the action of the capillary force of the porous hydrogel, thereby achieving heat dissipation in a reciprocating cycle.

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