A frameless torque motor stator, frameless torque motor and machine joint

Abstract

The application discloses a frameless torque motor stator, a frameless torque motor and a machine joint, and relates to the technical field of frameless torque motors. The motor stator comprises a stator core and a coil assembly. The stator core comprises a plurality of stampings which are laminated in the axial direction. Each stamping comprises a split magnetic yoke and a spoke tooth. The end of the spoke tooth away from the magnetic yoke is connected with a pole shoe. The stampings are divided into first stampings and second stampings. The second stampings are arranged at intervals between the laminated first stampings. There is a spacing between the two pole shoes which are circumferentially adjacent to each other in the first stamping. A magnetic bridge for connection is arranged between the two pole shoes which are circumferentially adjacent to each other in the second stamping. The coil assembly comprises a winding coil and a coil holder. The winding coil is wound on the coil holder. The coil holder is sleeved on the spoke tooth which is formed by lamination. The frameless torque motor stator can realize bidirectional balance of mechanical connection reinforcement and magnetic circuit leakage suppression, has high assembly efficiency, helps to improve the operation stability and precision of the machine joint, and reduces the production cost.

Description

Technical Field

[0001] This invention relates to the field of frameless torque motor technology, specifically to a frameless torque motor stator, a frameless torque motor, and a machine joint. Background Technology

[0002] Frameless torque motors are a special type of servo motor that eliminates the shaft, bearings, and housing of traditional motors, consisting only of two core components: a rotor and a stator. They can be directly embedded into the mechanical structure of equipment. With their compact structure, rapid response, and high torque density, frameless torque motors have become a core component for robot joint actuation. The stator structure directly determines the motor's operating accuracy, noise level, and lifespan.

[0003] Currently, the stators of ordinary frameless torque motors on the market are mainly divided into integral and split types. The integral stator adopts a continuous magnetic bridge design, which has serious magnetic leakage, high iron loss, complicated winding process, low slot fill factor, and cannot achieve modular mass production, resulting in poor adaptability. The split stator has no effective connection structure, and is prone to misalignment and deformation after assembly, resulting in uneven air gap between stator and rotor, high operating noise, and obvious torque fluctuation, which makes it difficult to meet the high precision and low noise drive requirements of robot joints.

[0004] Therefore, current frameless torque motor stators suffer from severe magnetic leakage, poor precision, and low assembly efficiency. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a frameless torque motor stator, a frameless torque motor and a machine joint, which solves the technical problems of serious magnetic leakage, poor precision and low assembly efficiency of the existing frameless torque motor stator.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a frameless torque motor stator, the stator comprising a stator core and a coil assembly. The stator core comprises a plurality of laminations stacked axially, each lamination comprising a separate magnetic yoke and spoke teeth, the ends of the spoke teeth away from the magnetic yoke being connected to pole shoes. The laminations are divided into first laminations and second laminations, the second laminations being spaced apart between the stacked plurality of first laminations. There is a gap between two circumferentially adjacent pole shoes of the first laminations. A magnetic bridge for connection is provided between two circumferentially adjacent pole shoes of the second laminations. The coil assembly comprises a wound coil and a coil frame, the wound coil being wound on the coil frame, and the coil frame being sleeved on the stacked spoke teeth.

[0007] In some embodiments, the spoke teeth and pole shoes of the first lamination are integrally formed; the spoke teeth, pole shoes and magnetic bridge of the second lamination are integrally formed.

[0008] In some embodiments, the thickness T1 of the magnetic bridge satisfies 0.3mm≤T1≤1.5mm; the thickness T2 of the lamination satisfies 0.1mm≤T2≤0.5mm.

[0009] In some embodiments, the laminations are silicon steel sheets, and the number of spoke teeth of each lamination along the circumferential direction is N1, satisfying 9≤N1≤36.

[0010] In some embodiments, along the stator core axis, the total number of laminations is N2, and the number of second laminations is N3, satisfying 1 / 15≤N3 / N2≤1 / 3.

[0011] In some embodiments, a guide chamfer is provided at one end of the spoke tooth near the yoke, the guide chamfer being used to guide the coil assembly to be fitted onto the stacked spoke tooth.

[0012] In some embodiments, the magnetic yokes are connected end to end in sequence along the circumferential direction of the laminations; along the axial direction of the stator core, the magnetic yokes in the laminations are stacked to form a magnetic yoke assembly, and the spokes in the laminations are stacked to form a spoke tooth assembly, with the magnetic yoke assembly and the spoke tooth assembly having a radial interference fit.

[0013] In some embodiments, the radial interference Y between the magnetic yoke assembly and the spoke tooth assembly satisfies 0.03mm≤Y≤0.1mm; the pressing pressure F between the magnetic yoke assembly and the spoke tooth assembly satisfies 5MPa≤F≤10MPa.

[0014] Secondly, the present invention also provides a frameless torque motor, which includes the above-mentioned motor stator, motor rotor, and radial clearance L between the outer circle of the motor rotor and the inner circle of the motor stator, satisfying 0.2mm≤L≤2mm.

[0015] Thirdly, the present invention also provides a machine joint comprising the aforementioned frameless torque motor.

[0016] Compared with existing technologies, the frameless torque motor stator provided by this invention forms a spacer-type discontinuous virtual magnetic bridge structure by stacking the first and second laminations; at the same time, it adopts a split magnetic yoke with spoke teeth to form a radial open slot; through the composite structure of "spacer-type discontinuous virtual magnetic bridge + radial open slot", it takes into account both the mechanical connection strength and magnetic circuit performance of the stator; and the coil is pre-wound on the coil frame to complete the pre-forming, relying on the split magnetic yoke and spoke tooth structure, the pre-made coil frame can be directly fitted onto the outside of the stacked spoke teeth, effectively overcoming the shortcomings of traditional structures such as the difficulty of overall winding and the dimensional accuracy of split assembly, and comprehensively improving the technical problems of serious magnetic leakage, low assembly accuracy and low winding processing efficiency of motor stators, meeting the comprehensive requirements of machine joints for positioning accuracy, production efficiency and operational stability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a frameless torque motor stator provided in an embodiment of the present invention; Figure 2 yes Figure 1 A magnified schematic diagram of part A in the middle section; Figure 3 This is a schematic diagram of the structure of the first lamination in the stator core provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the second lamination in the stator core provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the magnetic yoke assembly in the stator core provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the spoke tooth assembly in the stator core provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the coil assembly provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the coil frame structure in the coil assembly provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of a frameless torque motor provided in an embodiment of the present invention; Figure 10 This is a top view of the frameless torque motor provided in an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 10. Frameless torque motor; 100. Motor stator; 200. Motor rotor; 110. Stator core; 110A. Yoke assembly; 110B. Spoke tooth assembly; 111. Lamination; 1111. Yoke; 1112. Spoke tooth; 1113. Pole shoe; 1114. Magnetic bridge; 1115. Guide chamfer; 112. First lamination; 113. Second lamination; 120. Coil assembly; 121. Winded coil; 122. Coil frame. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] Frameless torque motors, with their compact structure, rapid response, and high torque density, have become core components for robot joint drives. Their stator structure directly determines the motor's operating accuracy, noise level, and lifespan. Currently, integral stators suffer from severe magnetic leakage, high iron losses, cumbersome winding processes, and low slot fill factor; while split stator components are prone to misalignment and deformation during assembly, leading to uneven air gaps between the stator and rotor, high operating noise, and difficulty meeting the high precision requirements of robot joints. Therefore, current frameless torque motor stators suffer from severe magnetic leakage, poor accuracy, and low assembly efficiency.

[0021] To address the technical problems of severe magnetic leakage, poor precision, and low assembly efficiency, this invention provides a frameless torque motor stator. This frameless torque motor stator can achieve a two-way balance between mechanical connection reinforcement and magnetic circuit leakage suppression, and has high assembly efficiency, which helps to improve the operational stability and precision of machine joints and reduces production costs.

[0022] It should be noted that the frameless torque motor stator provided by this invention is used in, but not limited to, industrial robots, precision automation equipment, and other scenarios where the accuracy and stability of the motor are required. For ease of explanation, this invention will only use the application of the frameless torque motor stator in industrial robots as an example. The principle of applying the frameless torque motor stator to other types of equipment is essentially the same as that applied to industrial robots, and will not be described in detail here.

[0023] This invention provides a frameless torque motor stator 100, such as... Figures 1 to 8 As shown, the motor stator 100 includes a stator core 110 and a coil assembly 120. The stator core 110 includes a plurality of laminations 111 stacked along the axial direction. Each lamination 111 includes a separate magnetic yoke 1111 and a spoke tooth 1112. The end of the spoke tooth 1112 away from the magnetic yoke 1111 is connected to a pole shoe 1113. The laminations 111 are divided into first laminations 112 and second laminations 113. The second laminations 113 are spaced apart between the plurality of stacked first laminations 112. There is a gap between two adjacent pole shoes of the first laminations 112 in the circumferential direction. A magnetic bridge 1114 for connection is provided between two adjacent pole shoes of the second laminations 113 in the circumferential direction. The coil assembly 120 includes a wound coil 121 and a coil frame 122. The wound coil 121 is wound on the coil frame 122, and the coil frame 122 is sleeved on the stacked spoke teeth 1112.

[0024] The stator core 110 is the core magnetic conductive component of the motor stator 100, responsible for magnetic field conduction and supporting the coil assembly 120. For example... Figures 2 to 4As shown, the stator core 110 is formed by stacking multiple laminations 111. The material of the laminations 111 is not limited, as long as it meets the usage requirements. Specific embodiments will be given later for explanation. Each lamination 111 includes a separate magnetic yoke 1111 and spoke teeth 1112. The magnetic yokes 1111 in the laminations 111 are stacked to form a magnetic yoke assembly, which is the outer ring magnetic yoke portion of the stator core 110; the spoke teeth 1112 in the laminations 111 are stacked to form a spoke tooth assembly, which is the inner ring tooth base of the stator core 110. Figure 5 and Figure 6 As shown, the magnetic yoke assembly 110A and the spoke tooth assembly 110B are manufactured using a separate punching and stacking process, and then pressed together to ensure the rigidity of the overall structure.

[0025] The stamping 111 can be specifically divided into the first stamping 112 and the second stamping 113, such as Figure 3 and Figure 4 As shown, the first lamination 112 includes multiple magnetic yokes 1111 along the circumferential direction, and radial spokes 1112 that correspond one-to-one with and are evenly distributed. The spokes 1112 have pole pieces 1113 at their tips. The difference between the first lamination 112 and the second lamination 113 is that the pole pieces 1113 in the first lamination 112 are not connected, while the pole pieces 1113 in the second lamination 113 are connected by magnetic bridges 1114. A magnetic bridge is a silicon steel sheet area between two pole pieces used to guide the magnetic circuit and reduce magnetic leakage. Its main function is to guide magnetic flux through the air gap to form effective magnetic flux, thereby improving the utilization rate of the permanent magnet.

[0026] For example, the spoke teeth 1112 in the first lamination 112 are integrally formed with the pole shoe 1113.

[0027] For example, the spoke teeth 1112, pole shoes 1113 and magnetic bridge 1114 in the second lamination 113 are integrally formed.

[0028] The arrangement of the second lamination 113 and the first lamination 112 is not limited; they can be arranged at uniform or non-uniform intervals. For example, multiple first laminations 112 are continuously stacked along the axial direction of the stator core 110, followed by one second lamination 113, and this process is repeated to form a discontinuous thin-walled magnetic bridge structure along the axial direction of the stator core 110, where several pole shoes are connected to one pole shoe. This achieves weak mechanical connection and micro-connection of the magnetic circuit, ensuring structural stability while effectively suppressing magnetic leakage.

[0029] It should be noted that, as Figure 5 and Figure 6As shown, the lamination 111 consists of separate magnetic yokes 1111 and spoke teeth 1112. Multiple magnetic yokes 1111 are stacked to form a magnetic yoke assembly 110A, and multiple spoke teeth 1112 are stacked to form a spoke tooth assembly 110B. The two are independent parts, which realizes the open large slot design of the spoke tooth assembly. The pre-made coil assembly 120 can be directly embedded in the spoke tooth assembly, and then the magnetic yoke assembly is connected to the spoke tooth assembly, thus eliminating the need for on-site winding and improving assembly efficiency.

[0030] Coil assembly 120 includes a wound coil 121 and a coil holder 122, such as Figure 7 and Figure 8 As shown, the winding coil 121 is mounted on the coil frame 122. The winding coil 121 serves as the armature winding of the motor. When an alternating current is applied, an alternating magnetic field can be generated on the stator core 110. This alternating magnetic field interacts with the magnetic field of the rotor permanent magnet, thereby generating an electromagnetic torque that drives the motor to rotate.

[0031] The coil 121 is wound on the coil frame 122 to form a coil, which is either a flat wire coil or a round wire coil.

[0032] The coil frame 122 serves as a physical separator between the winding coil 121 and the stator core 110. Since the stator core 110 is a high-permeability metal core, while the winding coil 121 is made of conductive copper or aluminum wire, the coil frame 122 effectively prevents direct contact between the coil and the core, preventing the sharp edges of the core from scratching the coil's insulating varnish and causing a short circuit. The material of the coil frame 122 is not particularly limited, as long as it meets the requirements for high temperature resistance and electrical insulation. For example, a plastic coil frame 122 can reliably block the current path between the coil and the stator core, ensuring the electrical safety of the motor operation.

[0033] It should be noted that the number of turns, wire diameter, and winding method of the winding coil 121 directly determine the rated voltage, rated current, torque density, and operating efficiency of the motor. The winding coil 121 can be neatly wound onto the coil frame 122 according to a preset number of turns and shape, realizing the prefabrication of the coil assembly 120. During assembly, the prefabricated coil assembly 120 can be directly fitted onto the stacked spoke tooth assembly, greatly improving assembly efficiency. Compared with the process of directly winding the coil on the spoke tooth assembly, it can also avoid the scrapping of the entire stator due to the scrapping of a single coil, thereby reducing manufacturing costs and helping to improve the yield rate.

[0034] In this embodiment, the first lamination 112 and the second lamination 113 are stacked to form a spacer-type intermittent virtual magnetic bridge structure; at the same time, a split magnetic yoke 1111 is used in combination with spoke teeth 1112 to form a radial open slot; through the composite structure of "spacer-type intermittent virtual magnetic bridge + radial open slot", both the mechanical connection strength and magnetic circuit performance of the stator are taken into account; and the coil is pre-wound on the coil frame 122 to complete the pre-forming. Relying on the split magnetic yoke 1111 and spoke teeth 1112 structure, the pre-made coil frame 122 can be directly fitted onto the outside of the stacked spoke teeth, which effectively overcomes the shortcomings of the traditional structure, such as the difficulty of overall winding and the lack of dimensional accuracy of split assembly, and improves the technical problems of serious magnetic leakage of the motor stator, low assembly accuracy and low winding processing efficiency.

[0035] Specifically, the frameless torque motor stator provided by this invention has a simple structure, strong process versatility, and can be adapted to both round and flat wire winding types. It improves mass production efficiency by over 30%, reduces manufacturing costs by 20%, and is easy to assemble, allowing direct use with various industrial robot joints. The stator's overall structure is highly rigid, capable of withstanding high-frequency impact loads from robot joints, and exhibits good operational stability. Compared to conventional frameless torque motor stators, this invention reduces leakage flux by over 25%, core loss by over 25%, and cogging torque by over 30%, while keeping operating noise below 55dB and achieving a slot fill factor of 80%-85%. Compared to traditional spliced ​​stators, concentricity and roundness machining accuracy are improved by 50%-150%, fully meeting the high-precision, low-noise drive requirements of robot joints.

[0036] In some embodiments, the thickness T1 of the magnetic bridge 1114 satisfies 0.3mm≤T1≤1.5mm; the thickness T2 of the lamination 111 satisfies 0.1mm≤T2≤0.5mm.

[0037] Specifically, in this embodiment, the thickness T1 of the magnetic bridge 1114 can be 0.3mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, or any value between any two adjacent values ​​mentioned above. By limiting the thickness of the magnetic bridge 1114 to between 0.3mm and 1.5mm, reliable connection of the pole shoes of the second lamination 113 is ensured, preventing magnetic bridge breakage and stator deformation; at the same time, the magnetic conductive area between the teeth is constrained, reducing ineffective leakage magnetic flux between the pole shoes, and balancing mechanical strength and electromagnetic performance. The thickness T2 of the lamination 111 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, or any value between any two adjacent values ​​mentioned above. By limiting the thickness of the lamination 111 to between 0.1mm and 0.5mm, eddy current losses generated by the alternating magnetic field can be reduced, improving motor operating efficiency; at the same time, the forming and stacking accuracy of the lamination is ensured, avoiding the problem of thin sheet warping and deformation, and ensuring the flatness of the stator core.

[0038] In some embodiments, such as Figure 3 and Figure 4 As shown, the lamination 111 is a silicon steel sheet. Along the circumference of the lamination 111, the number of spoke teeth 1112 of each lamination 111 is N1, which satisfies 9≤N1≤36.

[0039] Specifically, in this embodiment, lamination 111 is a silicon steel sheet, also known as electrical steel. It is a silicon-iron soft magnetic alloy with extremely low carbon content and 1.0%-4.5% silicon content, mainly used as the core of various motors, generators, and transformers. The silicon steel sheet can be, for example, a high-permeability silicon steel sheet. High-permeability silicon steel is a cold-rolled electrical steel with high magnetic permeability and low iron loss. Relying on the high permeability and low iron loss characteristics of silicon steel, stator eddy current and hysteresis losses are effectively reduced, improving motor efficiency. The number N1 of the spoke teeth 1112 of each lamination 111 can be 9, 12, 15, 18, 24, 32, 36, or any value between any two adjacent values ​​mentioned above. By setting the number of spoke teeth 1112 to 9-36, too few teeth will lead to excessive magnetic load on a single tooth, severe magnetic saturation, and increased torque fluctuation, while too many teeth will increase the difficulty of stamping and increase the cost of winding production. Reasonable arrangement of the number of teeth can balance magnetic load, tooth cogging torque and processing capability, make the air gap magnetic field distribution uniform, and output torque stable, which helps to adapt to various specifications of high-precision frameless torque motors.

[0040] In some embodiments, such as Figure 2 As shown, along the axial direction of the stator core 110, the total number of laminations 111 is N2, and the number of second laminations 113 is N3, satisfying 1 / 15≤N3 / N2≤1 / 3.

[0041] Specifically, in this embodiment, the second lamination 113 is a lamination with a thin-walled magnetic bridge. The ratio N3 / N2 of the number of second laminations 113 to the total number of laminations 111 can be 1 / 15, 1 / 12, 1 / 10, 1 / 8, 1 / 5, 1 / 3, or any value between any two adjacent values ​​mentioned above. For example, nine first laminations 112 are continuously stacked along the axial direction of the stator core 110, and then one second lamination 113 is stacked, with the proportion of the second lamination 113 being 1 / 10; or four first laminations 112 are continuously stacked along the axial direction of the stator core 110, and then one second lamination 113 is stacked, with the proportion of the second lamination 113 being 1 / 5. By limiting the proportion of the second lamination 113 to between 1 / 15 and 1 / 3, it is possible to prevent the number of magnetic bridges from becoming too many and creating a continuous magnetic bridge effect, thus avoiding magnetic leakage and rebound. It also ensures the minimum number of mechanical connection points, preventing the stator from axially dispersing, misaligning, or loosely stacking due to insufficient laminations with magnetic bridges. Furthermore, it allows for precise proportioning and control of motor performance. A proportion close to 1 / 3 emphasizes structural rigidity, making it suitable for heavy-duty impact joints; a proportion close to 1 / 15 emphasizes low loss, making it suitable for high-speed precision joints, thus significantly improving adaptability and flexibility.

[0042] In some embodiments, such as Figure 5 and Figure 6 As shown, the spoke tooth 1112 has a guide chamfer 1115 at one end near the magnetic yoke 1111. The guide chamfer 1115 is used to guide the coil assembly 120 to be sleeved on the stacked spoke tooth 1112.

[0043] Specifically, in this embodiment, multiple radial spoke teeth 1112 are evenly arranged circumferentially on the lamination 111. The spacing between the outer ends of the spoke teeth 1112 is the width of the open slot, which is wider than the width of the slot body. The outer ends of the spoke teeth 1112 are provided with guide chamfers 1115, and the chamfer angle can be determined according to actual needs, for example, a 45° chamfer. The guide chamfers 1115 can further expand the slot accommodating space, facilitating the assembly of modular windings. The guide chamfers 1115 have guiding and clearance functions. First, they eliminate jamming during the assembly of the coil frame 122, improving the smoothness of coil assembly. Second, they prevent the hard edges of the coil frame 122 from scratching the insulating varnish film of the iron core, preventing inter-turn short circuits and iron core leakage, and improving the insulation reliability and service life of the motor. In addition, the guide chamfers 1115 of the spoke teeth 1112 can also play a role in alignment guidance during the pressing process of the magnetic yoke assembly and the spoke tooth assembly, improving the pressing assembly accuracy.

[0044] In some embodiments, such as Figures 3 to 6 As shown, along the circumferential direction of the lamination 111, the magnetic yoke 1111 is connected end to end in sequence; along the axial direction of the stator core 110, the magnetic yoke 1111 in the lamination 111 is stacked to form a magnetic yoke assembly 110A, and the spoke teeth 1112 in the lamination 111 are stacked to form a spoke tooth assembly 110B. The magnetic yoke assembly 110A and the spoke tooth assembly 110B are radially interference fit.

[0045] Specifically, in this embodiment, the stator core 110 consists of an inner ring tooth base and an outer ring yoke. The yokes 1111 in the laminations 111 are stacked to form a yoke assembly, which is the outer ring yoke of the stator core 110; the spoke teeth 1112 in the laminations 111 are stacked to form a spoke tooth assembly, which is the inner ring tooth base of the stator core 110. The yoke assembly and the spoke tooth assembly are assembled using a separate stamping and stacking process, and then integrated using radial interference fitting.

[0046] For example, the radial interference Y between the yoke assembly and the spoke tooth assembly satisfies 0.03mm≤Y≤0.1mm; the pressing pressure F between the yoke assembly and the spoke tooth assembly satisfies 5MPa≤F≤10MPa. By limiting the interference to between 0.03mm and 0.1mm, the lower limit ensures radial clamping force, preventing loosening and abnormal noise of the teeth during no-load rotation; the upper limit prevents excessive interference from compressing the silicon steel sheet and causing plastic deformation, thus damaging the stator roundness; and by limiting the pressing pressure to between 5MPa and 10MPa, the magnetic crystal structure of the silicon steel sheet is protected from being crushed and damaged.

[0047] It is important to emphasize that the magnetic yoke assembly has a continuous ring structure along the circumference, ensuring overall rigidity and making the outer ring of the stator core 110 a complete circle. At least some of the pole shoes 1113 in the spoke tooth assembly are connected by magnetic bridges 1114, making the inner ring of the stator core 110 also have a complete circle structure. This constitutes the double-circular configuration of the stator core 110, with a concentricity error ≤0.02mm and a roundness error ≤0.02mm. By adopting a double-circular split-pressing structure, which is different from conventional integral stacking and segmented splicing stators, this structure, combined with a precision pressing process, breaks through the technical bottleneck of the industry where high precision and convenient winding, and high precision and high rigidity are difficult to achieve simultaneously. It solves the technical problems of stator precision, structural rigidity, winding assembly, and magnetic circuit efficiency. This double-circular configuration can simultaneously ensure processing accuracy, structural rigidity, and convenient winding assembly, effectively reducing core iron loss, improving motor operating efficiency and stability, and is suitable for various high-end precision drive conditions with strong operating stability.

[0048] This invention also provides a frameless torque motor 10, such as... Figure 9 and Figure 10 As shown, the frameless torque motor 10 includes a motor stator 100 and a motor rotor 200. The radial clearance L between the outer circle of the motor rotor 200 and the inner circle of the motor stator 100 satisfies 0.2mm≤L≤2mm.

[0049] Specifically, in this embodiment, the gap between the outer circle of the motor rotor and the inner circle of the motor stator is limited to 0.2mm-2mm to adapt to the magnetic load design requirements of different torque motor specifications; at the same time, the uniformity error of the circumferential air gap is controlled between 0.01mm-0.05mm to ensure a consistent circumferential magnetic field distribution, effectively suppressing unilateral magnetic pull, making the motor output torque stable, the vibration noise lower, and the operating noise ≤55dB, so as to adapt to the joint drive of industrial robots.

[0050] This invention also provides a machine joint, which includes a frameless torque motor 10. Specifically, the machine joint includes industrial robot joints, precision automated equipment joints, collaborative robot joints, etc.

[0051] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A frameless torque motor stator, characterized in that, include: A stator core includes multiple laminations stacked axially, each lamination including a separate magnetic yoke and spoke teeth, the end of the spoke teeth away from the magnetic yoke being connected to a pole shoe; The laminations are divided into first laminations and second laminations, with the second laminations spaced apart between multiple stacked first laminations; there is a gap between two circumferentially adjacent pole pieces of the first laminations; and a magnetic bridge for connection is provided between two circumferentially adjacent pole pieces of the second laminations. A coil assembly includes a wound coil and a coil frame, the wound coil being wound on the coil frame and the coil frame being fitted onto the stacked spoke teeth.

2. The motor stator according to claim 1, characterized in that, The spoke teeth and pole shoes of the first lamination are integrally formed; the spoke teeth, pole shoes and magnetic bridge of the second lamination are integrally formed.

3. The motor stator according to claim 1, characterized in that, The thickness T1 of the magnetic bridge satisfies 0.3mm≤T1≤1.5mm; the thickness T2 of the lamination satisfies 0.1mm≤T2≤0.5mm.

4. The motor stator according to claim 1, characterized in that, The lamination is a silicon steel sheet, and the number of spoke teeth of each lamination along the circumference is N1, satisfying 9≤N1≤36.

5. The motor stator according to claim 1, characterized in that, Along the axial direction of the stator core, the total number of laminations is N2, and the number of second laminations is N3, satisfying 1 / 15≤N3 / N2≤1 / 3.

6. The motor stator according to claim 1, characterized in that, The spoke tooth has a guide chamfer at one end near the yoke, and the guide chamfer is used to guide the coil assembly to be fitted onto the stacked spoke tooth.

7. The motor stator according to claim 1, characterized in that, Along the circumferential direction of the laminations, the magnetic yokes are connected end to end in sequence; along the axial direction of the stator core, the magnetic yokes in the laminations are stacked to form a magnetic yoke assembly, and the spokes in the laminations are stacked to form a spoke tooth assembly, and the magnetic yoke assembly and the spoke tooth assembly are radially interference fit.

8. The motor stator according to claim 7, characterized in that, The radial interference Y between the magnetic yoke assembly and the spoke tooth assembly satisfies 0.03mm≤Y≤0.1mm; the pressing pressure F between the magnetic yoke assembly and the spoke tooth assembly satisfies 5MPa≤F≤10MPa.

9. A frameless torque motor, characterized in that, include: The motor stator as described in any one of claims 1-8; The radial clearance L between the outer circle of the motor rotor and the inner circle of the motor stator satisfies 0.2mm≤L≤2mm.

10. A machine joint, characterized in that, Including the frameless torque motor as described in claim 9.

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