A frameless torque motor applied to a robot

Abstract

The present invention discloses a frameless torque motor applied to a robot, which includes a stator assembly and a double-rotor assembly. The stator assembly includes a stator support frame and a plurality of independent stator elements. Each independent stator element is circumferentially distributed on the stator support frame, and the stator support frame and each independent stator element are integrally formed by insulating glue injection molding. The double-rotor assembly includes two shaftless rotors, and the two shaftless rotors are used to clamp on the stator assembly so that the frameless torque motor forms a closed-loop double-sided magnetic circuit coupling, and the two shaftless rotors are symmetrically arranged on the stator assembly. By separating the teeth part and the yoke part of the traditional axial motor and abandoning the stator yoke part, the present invention can effectively reduce the volume of the motor itself and improve the space utilization rate. By adopting the structure of rotor-stator-rotor to form a magnetic circuit closed loop and fixing the stator teeth and integrally molding them with injection molding materials, the motor assembly is simple and the cost is low. And by setting the double-rotor assembly, the output torque is effectively increased.

Description

Technical Field

[0001] The present invention relates to the field of frameless torque motors, and particularly to a frameless torque motor applied to a robot. Background Art

[0002] Existing radial frameless torque motors mostly adopt an inner rotor structure, where the coil is fixed to the housing and the main shaft is the rotor. Although high-speed operation can be achieved, it is limited by the small number of poles and small moment of inertia, resulting in weak torque output ability. In addition, the installation space of existing radial frameless torque motors in the robotic arm is limited. To meet the high torque output, the axial height needs to be increased, which conflicts with the limited installation space and cannot meet higher torque requirements. Moreover, due to the special structure without a housing and bearings in existing radial frameless torque motors, the requirements for the precision and concentricity of the stator and rotor are extremely high. Minor deviations easily lead to vibration and noise, and high-precision equipment is required to support the winding, magnet installation, etc. The material cost and processing difficulty are significantly increased. Summary of the Invention

[0003] An object of the present invention is to overcome the deficiencies in the prior art and provide a frameless torque motor applied to a robot, which solves the problems of small torque output, limited installation space, and high manufacturing and maintenance costs of traditional radial frameless torque motors.

[0004] The object of the present invention is achieved by the following technical solutions:

[0005] A frameless torque motor applied to a robot, comprising:

[0006] A stator assembly, the stator assembly includes a stator support frame and a plurality of independent stator elements, each of the independent stator elements is circumferentially distributed on the stator support frame, and the stator support frame and each of the independent stator elements are integrally formed by insulating glue injection molding;

[0007] A dual-rotor assembly, the dual-rotor assembly includes two shaftless rotors, and the two shaftless rotors are used to clamp on the stator assembly to form a closed-loop double-sided magnetic circuit coupling of the frameless torque motor, and the two shaftless rotors are symmetrically arranged on the stator assembly.

[0008] In one embodiment, the stator support frame and each of the independent stator elements are integrally injection molded to form an injection plastic body structure, and the two shaftless rotors are respectively symmetrically arranged on the injection plastic body structure.

[0009] In one embodiment, in one of the independent stator elements, the independent stator element includes a housing, stator teeth, and a coil, the stator teeth are wrapped in the housing, the coil is wound outside the housing, and a plurality of injection cavities are formed on the injection plastic body structure, and each of the housing and the coil is installed in the injection cavity.

[0010] In one embodiment, the housing includes a bottom plate, a gear sleeve and an upper cover. The bottom plate and the upper cover are respectively installed on two end faces of the gear sleeve, and an installation cavity is formed in the gear sleeve, and the stator teeth are accommodated in the installation cavity.

[0011] In one embodiment, a first positioning through hole is formed in the stator teeth, a second positioning through hole is formed in the bottom plate, and a third positioning through hole is formed in the upper cover. The first positioning through hole, the second positioning through hole and the third positioning through hole are communicated with each other.

[0012] In one embodiment, the first positioning through hole, the second positioning through hole and the third positioning through hole are equal in number.

[0013] In one embodiment, the stator support frame includes a metal fixing ring and a plurality of fixing pins. Each fixing pin is respectively arranged on the metal fixing ring, and each fixing pin is arranged between two independent stator parts.

[0014] In one embodiment, in a shaftless rotor, the shaftless rotor includes an open rotor back iron and a plurality of permanent magnets. An annular installation groove is formed in the open rotor back iron, and each permanent magnet is respectively arranged in the annular installation groove.

[0015] In one embodiment, the shaftless rotor further includes a plurality of partition bars. Each partition bar is respectively arranged in the annular installation groove so that the annular installation groove is separated into a plurality of independent installation areas, and each permanent magnet is respectively arranged in one of the installation areas in one-to-one correspondence.

[0016] In one embodiment, the open rotor back iron includes an annular cover plate, an inner fixing plate and an outer fixing plate. The inner fixing plate is arranged on the inner circumferential circle of the annular cover plate, the outer fixing plate is arranged on the outer circumferential circle of the annular cover plate, and the annular cover plate, the inner fixing plate and the outer fixing plate jointly enclose the annular installation groove.

[0017] The advantages and beneficial effects of the present invention compared with the prior art are as follows:

[0018] 1. The present invention is a frameless torque motor applied to a robot. By separating the tooth part and the yoke part of a traditional axial motor and abandoning the stator yoke part, the volume of the motor itself can be effectively reduced, and the space utilization rate can be improved; and by adopting a rotor-stator-rotor structure, a closed-loop double-sided magnetic circuit coupling is formed, and the stator teeth are fixed and injection-molded into one body with an injection molding material, so that the motor assembly is simple and the cost is low; and by arranging a double-rotor assembly, the output torque is effectively increased.

[0019] 2. The present invention can directly install the stator and rotor on the robotic arm of a robot without using bearings, and the relative positions of the stator and rotor can be completely fixed by the mounting structure, which can effectively reduce the air gap and solve the problem of the radial magnetic pull force of traditional axial motors. In addition, compared with traditional radial frameless torque motors with the same torque output, the present invention can effectively reduce the axial height, and there are more specification options to meet different torque requirements; at the same time, the torque output can be increased by increasing the number of axial stators and rotors. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a structural diagram of a frameless torque motor applied to a robot according to an embodiment of the present invention;

[0021] Figure 2 is Figure 1 an exploded view of the frameless torque motor applied to a robot shown in;

[0022] Figure 3 is Figure 1 an exploded view of the stator assembly of the frameless torque motor applied to a robot shown in;

[0023] Figure 4 is Figure 3 an exploded view of the stator teeth of the stator assembly shown in;

[0024] Figure 5 is Figure 1 an exploded view of the shaftless rotor of the frameless torque motor applied to a robot shown in;

[0025] Figure 6 is a comparison curve graph of the cogging torque of the present invention and a traditional motor;

[0026] Figure 7 is a comparison curve graph of the torque of the present invention and a traditional motor;

[0027] Among them, the reference numerals in the drawings are as follows:

[0028] 10. Stator assembly; 11. Stator support frame; 111. Metal fixing ring; 112. Fixing pin; 12. Independent stator part; 121. Housing; 122. Stator teeth; 122a. First positioning through hole; 123. Coil; 124. Bottom plate; 125. Tooth sleeve; 126. Upper cover; 127. Installation inner cavity; 13. Injection plastic body structure; 20. Double rotor assembly; 21. Shaftless rotor; 22. Open rotor back iron; 221. Ring-shaped cover plate; 222. Inner fixing plate; 223. Outer fixing plate; 23. Magnet; 24. Partition strip. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0030] It can be understood that the special structure of the existing motor without a housing and bearings has extremely high requirements for the accuracy and concentricity of the stator and rotor. Minor deviations are likely to cause vibration and noise, and high-precision equipment is required to support links such as winding and magnet installation, significantly increasing the material cost and processing difficulty. Moreover, the proportion of the inner rotor structure in the existing motor exceeds 70%, with a small number of poles and a small moment of inertia. The torque density under the same volume is only 77% of that of the axial motor, making it difficult to meet the high torque density requirements of robot joints. It is necessary to customize the shape and performance parameters according to the mechanical design dimensions, lacking standardized products, and having harsh requirements for electromagnetic design and production process experience, which restricts large-scale application. Although the structure is compact, it relies on external bearings for support and has no design for vulnerable parts, posing higher challenges to the installation process and system integration flexibility. The installation space in the radial direction of the robotic arm is limited. To meet the high torque output, the axial height needs to be increased, which conflicts with the limited installation space and cannot meet higher torque requirements.

[0031] Based on this, please refer to Figures 1 to 5 , a frameless torque motor applied to a robot, comprising: a stator assembly 10 and a dual-rotor assembly 20. It should be noted that it also includes three-phase stator leads, and the three-phase stator leads are arranged on the stator assembly.

[0032] The stator assembly 10 includes a stator support frame 11 and a plurality of independent stator elements 12. Each of the independent stator elements 12 is circumferentially distributed on the stator support frame 11, and the stator support frame 11 and each of the independent stator elements 12 are integrally formed by insulating glue injection molding. It should be noted that the stator assembly 10 is composed of the stator support frame 11 and a plurality of independent stator elements 12. The stator support frame 11 serves as a support framework, not only providing the necessary mechanical strength but also ensuring the precise positioning of all independent stator elements 12. These independent stator elements 12 are evenly distributed along the circumference of the stator support frame 11, forming a key part of the motor magnetic field. They are integrated with the stator support frame 11 through insulating glue injection molding technology. This design not only enhances the integrity of the structure but also effectively isolates electrical components, improving the safety and reliability of the motor.

[0033] Please refer to Figure 2, the dual-rotor assembly 20 includes two shaftless rotors 21. The two shaftless rotors 21 are used to clamp onto the stator assembly 10 to form a closed-loop double-sided magnetic circuit coupling for the frameless torque motor, and the two shaftless rotors 21 are symmetrically arranged on the stator assembly 10. It should be noted that the shaftless rotor 21 directly interacts with the stator assembly 10 through the magnets on its outer periphery without the need for a traditional axial center support, thereby reducing frictional losses and improving efficiency. The two shaftless rotors 21 are used to clamp the stator assembly 10, forming a closed-loop double-sided magnetic circuit coupling system. This not only enhances the torque density of the motor but also enables the motor to maintain high stability and rapid response during high-speed operation. The two shaftless rotors 21 are symmetrically arranged, ensuring a balanced distribution of the magnetic field, reducing vibration and noise, and improving the overall performance.

[0034] Furthermore, the magnetic field generated by the independent stator part 12 in the stator assembly 10 interacts with the magnets in the dual-rotor assembly 20. When current passes through the stator coil, a changing magnetic field is generated, and this magnetic field interacts with the permanent magnets or electromagnetic structures on the rotor, thereby generating a rotational torque. Due to the adoption of the closed-loop double-sided magnetic circuit coupling design, the magnetic field energy circulates between the two rotors, enhancing the utilization efficiency of the magnetic field, enabling the motor to output a larger torque while maintaining high efficiency; as Figure 7 shown, Figure 7 in which the horizontal axis represents the rotational speed change and the vertical axis represents the torque change; compared with the traditional radial motor, the motor torque of the present invention is greater and the efficiency is higher at the same rotational speed. In addition, the symmetrical rotor layout helps to reduce the imbalance of the radial force and axial force, prolong the bearing life, and improve the durability of the motor.

[0035] In this way, by separating the tooth part and yoke part of the traditional axial motor and discarding the stator yoke, the volume of the motor itself can be effectively reduced and the space utilization rate can be improved; by adopting the rotor-stator-rotor structure to form a magnetic circuit closed loop, fixing the stator teeth 122 and injecting them into one body with an injection molding material, the motor assembly is simple and the cost is low; and by setting the dual-rotor assembly 20, the output torque is effectively increased.

[0036] The axial frameless torque motor, through an innovative magnetic circuit design, adopts a planar stator-rotor arrangement, enabling the magnetic field to be distributed axially, significantly shortening the magnetic flux path and enhancing the power density. The torque density can reach 1.3 times that of the radial motor under the same volume. In addition, this structure removes the traditional housing and bearings, achieving ultra-thin and lightweight (the axial length is only 50% of that of the radial motor), and adapting to the stringent requirements of robot joints for compact space and high torque density.

[0037] It should also be noted that the combination of the frameless design and the bilateral magnetic circuit coupling greatly improves the energy conversion efficiency of the motor, reduces energy loss, and is applicable to robot applications that require high power density and precise control. The shaftless rotor 21 design makes the overall structure of the motor more compact, saves installation space, facilitates integration into the compact structure of the robot, and improves the flexibility and operating range of the robot. The symmetrical rotor layout and optimized magnetic field design effectively reduce the noise and vibration generated during operation, improve the comfort of the working environment, and also extend the service life of the motor. Due to the efficient utilization of the magnetic field and the stability of the structure, the motor can achieve high-precision position control and speed regulation, meeting the accuracy requirements of complex robot tasks. The modular stator assembly 10 and the easily detachable dual-rotor assembly 20 simplify the maintenance process, reduce the maintenance cost, and improve the overall operation and maintenance efficiency of the robot.

[0038] Furthermore, the injection molding material (such as epoxy resin or modified plastic) in the present invention has viscoelasticity, which can convert electromagnetic vibration energy into heat energy dissipation, inhibit the transmission of high-frequency vibration to the outside of the motor or external structure. The injection molding body fills the gap between the stator core and the winding, eliminates the micro-gap vibration amplification effect caused by traditional bolt fixation, and reduces the risk of mechanical resonance. The injection molding process bonds the independent stator part 12 and the support frame into a whole, improves the structural rigidity, reduces the loosening or displacement of the stator teeth 122 or the coil 123 caused by the electromagnetic force pulsation, thereby suppressing the mid-low frequency vibration. The injection molding layer forms a continuous wrapping layer on the stator surface, blocking the path of vibration transmission from the stator to the rotor through the air gap, and reducing the noise caused by the uneven air gap magnetic field. And the symmetrical layout of the dual rotors makes the magnetic field distribution symmetrical on both sides of the stator assembly 10, canceling out the unilateral magnetic pull of the traditional single-rotor structure, avoiding the periodic radial vibration caused by the electromagnetic force imbalance. The closed-loop bilateral magnetic circuit shortens the magnetic flux path, reduces the hysteresis loss and eddy current loss, and reduces the thermal deformation and vibration caused by energy loss. The symmetrical coupling magnetic field of the dual rotors can reduce the electromagnetic torque pulsation, make the motor run more smoothly, reduce the low-frequency vibration noise, and the circumferential array and symmetrical distribution of the permanent magnets 23 enhance the magnetic field uniformity and weaken the high-order harmonic magnetic field components, reducing the high-frequency electromagnetic noise. The injection molding process mainly absorbs high-frequency vibration (>1 kHz), while the symmetrical magnetic circuit design reduces mid-low frequency vibration (50 Hz–1 kHz). The combination of the two achieves noise reduction in the full frequency band. In addition, the injection molding layer, as a mechanical impedance interface, hinders the transmission of vibration energy from the stator to the outside; the symmetrical magnetic circuit reduces the generation of vibration energy through magnetic field optimization, forming a double suppression mechanism.

[0039] In this embodiment, please refer to Figure 3, the stator support frame 11 and each of the independent stator components 12 are injection-molded into one body to form an injection-molded plastic structure 13, and the two shaftless rotors 21 are respectively symmetrically arranged on the injection-molded plastic structure 13. In this way, the stator support frame 11 and each independent stator component 12 are integrated by the injection molding process to form a strong injection-molded plastic structure 13. This not only simplifies the assembly process, improves production efficiency, but also enhances the overall rigidity and seismic performance of the stator assembly 10.

[0040] Please refer to Figure 3 and Figure 4 , in one of the independent stator components 12, the independent stator component 12 includes a housing 121, stator teeth 122 and a coil 123. The stator teeth 122 are wrapped inside the housing 121, and the coil 123 is wound outside the housing 121. A number of injection cavities are formed on the injection-molded plastic structure 13, and each housing 121 and the coil 123 are installed in the injection cavities. It should be noted that the housing 121, as a protective structure, wraps the stator teeth 122 and the coil 123 inside, which not only prevents interference from the external environment, but also ensures the safety of the internal components. The stator teeth 122 are made of a magnetic conductive material, which has the function of optimizing the magnetic field distribution and enhancing the electromagnetic coupling effect. The coil 123 is wound outside the housing 121. When an electric current passes through it, a changing magnetic field will be generated, which interacts with the magnets or electromagnetic structures on the shaftless rotor 21 to generate a rotational torque.

[0041] Please refer to Figure 3 and Figure 4 , the housing 121 includes a bottom plate 124, a tooth sleeve 125 and an upper cover 126. The bottom plate 124 and the upper cover 126 are respectively installed on the two end faces of the tooth sleeve 125, and an installation inner cavity 127 is formed inside the tooth sleeve 125, and the stator teeth 122 are accommodated in the installation inner cavity 127. It should be noted that the bottom plate 124 is used as the bottom support of the housing 121; the tooth sleeve 125 is the core part of the housing 121, and an installation inner cavity 127 is formed inside it for accommodating the stator teeth 122. The material selection of the tooth sleeve 125 needs to consider both magnetic conductivity and mechanical strength to ensure that the stator teeth 122 can be stably fixed in the installation inner cavity 127 and effectively transmit the magnetic field; the upper cover 126, as the top cover of the housing 121, not only provides additional protection, but also forms a closed cavity in close cooperation with the bottom plate 124 and the tooth sleeve 125 through its structural design to prevent interference from the external environment.

[0042] Furthermore, please refer to Figure 4, a first positioning through hole 122a is formed in the stator tooth 122, a second positioning through hole is formed in the bottom plate 124, and a third positioning through hole is formed in the upper cover 126. The first positioning through hole, the second positioning through hole, and the third positioning through hole are communicated with each other. In this embodiment, the first positioning through hole, the second positioning through hole, and the third positioning through hole are the same in number. Preferably, the number of the first positioning through holes is two. Two positioning through holes are axially formed in the stator tooth 122 for positioning between different teeth in the circumferential direction. After the stator tooth 122 is wound with wire, the stator teeth 122 are arranged in a circle according to the motor winding principle, and are positioned by two round holes in the stator tooth 122, and then the metal fixing ring 111 and the fixing pin 112 are injection-molded together to form an integrally injection-molded body structure 13.

[0043] Please refer to Figure 3 and Figure 4 , the stator support frame 11 includes a metal fixing ring 111 and a plurality of fixing pins 112. Each of the fixing pins 112 is respectively arranged on the metal fixing ring 111, and each of the fixing pins 112 is arranged between two of the independent stator members 12. It should be noted that a metal fixing ring 111 is arranged on the stator support frame 11, and a fixing pin 112 is provided between the stator teeth 122 to connect the metal fixing ring 111 and the injection-molded stator assembly 10 for fixing the entire stator assembly 10. The metal fixing ring 111 is used to provide a stable support platform for the stator assembly 10; the fixing pin 112 is used to fix the stator member, and also plays a role in separating and positioning, and can also absorb and disperse vibration energy to a certain extent, improving the running stability and service life of the device. There is a fixing pin 112 in the gap between every two stator teeth 122 for strengthening the structural strength of the injection-molded stator assembly 10 and the inner wall metal fixing ring 111. One part of the positioning pin is injection-molded in the injection-molded body structure 13 of the stator assembly 10, and the other end is connected to the metal ring.

[0044] Please refer to Figure 5, in one of the shaftless rotors 21, the shaftless rotor 21 includes an open rotor back iron 22 and a plurality of permanent magnets 23. An annular mounting groove is formed on the open rotor back iron 22, and each of the permanent magnets 23 is disposed in the annular mounting groove. It should be noted that the open rotor back iron 22 is used as the main structure of the shaftless rotor 21; the annular mounting groove provides space for the embedding of the permanent magnets 23, promotes heat dissipation, and improves the thermal stability of the rotor; the permanent magnets 23 are responsible for generating a strong magnetic field to ensure the required electromagnetic force can be generated when the rotor rotates. There is no connecting structure between the stator assembly 10 of the frameless torque motor and the two rotors, and the relative positions of these three parts are fixed through the structure of the robotic arm; and the two rotor structures are the same and symmetric. An annular mounting groove is formed in the open rotor back iron 22, and the permanent magnets 23 are glued or injection-molded in the annular mounting groove. The back iron is a magnetic conductive material and is part of a closed magnetic circuit.

[0045] Furthermore, an open rotor back iron 22 and an annular mounting groove for the permanent magnets 23 are provided in the rotor. It allows the permanent magnets 23 to fit on the surface of the stator assembly 10, which can effectively shorten the air gap, reduce the magnetic resistance and magnetic field distortion, thereby weakening the electromagnetic force pulsation caused by the uneven magnetic field; and the symmetric dual-rotor layout can cancel the unilateral magnetic pull force, eliminate the radial electromagnetic force imbalance of the traditional single-rotor structure, and suppress mid- and low-frequency vibrations; the annular mounting groove of the permanent magnets 23 and the stator teeth 122 form a closed-loop magnetic circuit, reducing magnetic leakage and high-order harmonic components, reducing the cogging torque pulsation, and reducing high-frequency electromagnetic noise, as Figure 6 shown. Figure 6 In the figure, the horizontal axis is the angle change, and the vertical axis is the cogging torque; compared with the traditional radial motor, the cogging torque of the present invention has smaller pulsation changes and the overall cogging torque is more stable; after the annular mounting groove of the permanent magnets 23 fits with the stator assembly 10, the injection-molded material is filled on the stator assembly 10, and the viscoelastic properties of the material are used to convert the high-frequency vibration energy into heat energy, which is quickly dissipated through the heat dissipation channels of the open structure; the open design increases the air gap heat dissipation area, combined with the symmetric layout of the permanent magnet 23 slots, reduces the temperature rise of the coil 123, reduces the mechanical deformation and vibration caused by thermal expansion, and further reduces the generation of noise.

[0046] Please refer to Figure 5 , the shaftless rotor 21 further includes a plurality of partition bars 24, and each of the partition bars 24 is disposed in the annular mounting groove to separate the annular mounting groove into a plurality of separate mounting areas, and each of the permanent magnets 23 is correspondingly disposed in the mounting areas. The partition bars 24 are used to prevent direct contact between the permanent magnets 23, reduce the potential risk of magnetic short circuit, and improve the utilization efficiency of magnetic energy by optimizing the magnetic field distribution.

[0047] Please refer to Figure 5, the open rotor back iron 22 includes an annular cover plate 221, an inner fixing plate 222 and an outer fixing plate 223. The inner fixing plate 222 is disposed on the inner circumferential circle of the annular cover plate 221, and the outer fixing plate 223 is disposed on the outer circumferential circle of the annular cover plate 221. The annular cover plate 221, the inner fixing plate 222 and the outer fixing plate 223 together enclose an annular installation groove, and each of the partition strips 24 is respectively disposed on the annular cover plate 221. It should be noted that the annular cover plate 221 is used to provide necessary structural support; and by setting the inner fixing plate 222 and the outer fixing plate 223 for reinforcement, the strength and stability of the rotor back iron are ensured.

[0048] Compared with the outer rotor radial motor, the solution of the present invention improves the torque output capacity by more than 40% while maintaining a high rotational speed response by optimizing the winding layout and magnetic circuit coupling efficiency, providing a better solution for robot motion control. The present invention solves the problem of small output torque of the existing radial frameless torque motor, and also solves the problems of difficult manufacturing and axial magnetic pull force of the existing axial motor. By directly installing the rotor and the stator on the robotic arm, the relative positions of the two rotors and the stator are absolutely fixed, and there is no increase in mechanical loss caused by axial magnetic pull force, making it more efficient than the traditional axial motor.

[0049] The above-described embodiments merely represent several embodiments of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the appended claims.

Claims

1. A frameless torque motor applied to a robot, characterized in that, Comprising: A stator assembly, the stator assembly including a stator support frame and a plurality of independent stator elements, each of the independent stator elements being circumferentially distributed on the stator support frame, and the stator support frame and each of the independent stator elements being injection molded into one body by insulating glue; A dual-rotor assembly, the dual-rotor assembly including two shaftless rotors, the two shaftless rotors being used for clamping on the stator assembly so that a frameless torque motor forms a closed-loop double-sided magnetic circuit coupling, and the two shaftless rotors being symmetrically arranged on the stator assembly; The stator support frame and each of the independent stator elements are injection molded into one body to form an injection plastic body structure, and the two shaftless rotors are respectively symmetrically arranged on the injection plastic body structure; In one of the independent stator elements, the independent stator element includes a housing, stator teeth and a coil, the stator teeth being wrapped in the housing, the coil being wound outside the housing, and a plurality of injection cavities being formed in the injection plastic body structure, each of the housing and the coil being installed in the injection cavity; The housing includes a bottom plate, a tooth sleeve and an upper cover, the bottom plate and the upper cover being respectively installed on both end faces of the tooth sleeve, and an installation inner cavity being formed in the tooth sleeve, the stator teeth being accommodated in the installation inner cavity.

2. The frameless torque motor applied to a robot according to claim 1, wherein A first positioning through hole is formed in the stator teeth, a second positioning through hole is formed in the bottom plate, and a third positioning through hole is formed in the upper cover, and the first positioning through hole, the second positioning through hole and the third positioning through hole communicate with each other.

3. The frameless torque motor applied to a robot according to claim 2, characterized in that, The first positioning through hole, the second positioning through hole and the third positioning through hole are the same in number.

4. The frameless torque motor applied to a robot according to any one of claims 1 to 3, characterized in that, The stator support frame includes a metal fixing ring and a plurality of fixing pins, each of the fixing pins being respectively arranged on the metal fixing ring, and each of the fixing pins being arranged between two of the independent stator elements.

5. The frameless torque motor applied to a robot according to claim 1, wherein In one of the shaftless rotors, the shaftless rotor includes an open rotor back iron and a plurality of permanent magnets, an annular installation groove being formed in the open rotor back iron, and each of the permanent magnets being respectively arranged in the annular installation groove.

6. The frameless torque motor applied to a robot according to claim 5, wherein, The shaftless rotor further includes a plurality of partition strips, each of the partition strips being respectively arranged in the annular installation groove so that the annular installation groove is separated into a plurality of separate installation areas, and each of the permanent magnets being respectively arranged in one-to-one correspondence in the installation areas.

7. The frameless torque motor applied to a robot according to claim 5, wherein The open rotor back iron includes an annular cover plate, an inner side fixing plate and an outer side fixing plate, the inner side fixing plate being arranged on the inner circumferential circle of the annular cover plate, the outer side fixing plate being arranged on the outer circumferential circle of the annular cover plate, and the annular cover plate, the inner side fixing plate and the outer side fixing plate jointly enclose the annular installation groove.

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