Low-torque pulsation joint motor for a robot dog

Abstract

The utility model discloses a low torque pulsation joint motor for robot dog, including stator and rotor, the inside of stator is equipped with the mounting hole for the rotor insertion, the stator is equipped with 24 stator slots of equal division degree setting in the inner wall perimeter side of mounting hole, and is equipped with the concentrated winding in each stator slot, the outside of rotor is equipped with 28 magnetic steel of equal distribution setting, one side of each magnetic steel is equipped with arc surface with mounting hole, and the curvature of arc surface is greater than the curvature of mounting hole, and the arc surface is used for changing the magnetic pole shape of magnetic steel, so that the magnetic field can realize more gentle transition in the magnetic pole edge area, the motor in the utility model has low torque pulsation characteristic, and robot dog can realize more accurate control when performing tasks such as grabbing articles, crossing obstacles, accurate positioning etc, greatly improves the success rate and delicacy of task completion.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, specifically a low-torque pulsating joint motor for a robot dog. Background Technology

[0002] With the rapid development of robotics technology, robot dogs have shown broad application prospects in many fields, such as rescue, inspection, and logistics delivery. However, the complex and varied movement patterns of robot dogs place extremely high demands on their joint drive motors. Traditional motors used in robot dog joints generally suffer from large torque ripple. This not only causes significant vibration and shaking during walking, running, and climbing, affecting the stability of movement, but also reduces the precision of motion control, making it difficult for robot dogs to perform some fine movements, such as grasping small objects or moving precisely in confined spaces. Furthermore, large torque ripple also leads to increased additional losses, increased noise, and shortened lifespan of the motor, severely restricting the overall performance improvement of the robot dog. Therefore, developing a robot dog joint motor that can significantly reduce torque ripple is urgently needed. Utility Model Content

[0003] To address the shortcomings of existing technologies, this utility model provides a low-torque pulsating joint motor for robot dogs.

[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution: This utility model discloses a low-torque pulsating joint motor for a robot dog, comprising a stator and a rotor; the stator has an internal mounting hole for inserting the rotor, and the stator has 24 stator slots evenly spaced on the inner wall of the mounting hole, each stator slot containing a concentrated winding; the rotor has 28 magnets evenly distributed on its outer side. Each magnet has an arched surface on the side opposite the mounting hole, and the curvature of the arched surface is greater than that of the mounting hole. The arched surface is used to change the shape of the magnet's poles, so that the magnetic field can achieve a smoother transition in the edge region of the poles, and the spatial distribution of the magnetic flux generated by the beveled magnet is closer to the ideal sine function shape. An unequal air gap is formed between the magnet and the inner wall of the mounting hole under the action of beveling. The stator slots are inclined and arranged on the inner wall to form inclined slots.

[0005] As a preferred technical solution of this utility model, the stator slot adopts a parallel tooth arc-shaped flat-bottomed slot.

[0006] As a preferred technical solution of this utility model, the stator and rotor are formed by stacking high-saturation ultra-thin silicon steel sheets.

[0007] As a preferred embodiment of this invention, the rotor is provided with a hollow shaft.

[0008] As a preferred embodiment of this invention, the inclination angle of the inclined groove is a mechanical angle corresponding to one tooth pitch.

[0009] As a preferred technical solution of this utility model, the centralized winding is provided with multiple layered windings, and an insulation layer is provided between the multiple layered windings; the multiple layered windings are arranged in parallel; after the layered windings are completed, a vacuum pressure impregnation process is used to immerse the layered windings in insulating varnish, and the air inside the layered windings is removed in a vacuum environment, and then a certain pressure is applied to make the insulating varnish fully penetrate into each gap of the layered windings.

[0010] The beneficial effects of this utility model are: This type of robotic dog uses a low-torque pulsation joint motor. Due to the motor's low-torque pulsation characteristics, the joints can achieve more precise control when performing tasks such as grasping objects, overcoming obstacles, and accurate positioning, greatly improving the success rate and precision of task completion. In the robotic dog's daily movements such as walking, running, jumping, and turning, the low torque pulsation makes the joint movements natural and smooth, preventing limb tremors and stuttering caused by unstable motor torque. This not only makes the robotic dog's appearance and movements more human-like and elegant, but also reduces the impact and wear on the robotic dog's structure caused by unnecessary vibrations, extending the robotic dog's service life. Attached Figure Description

[0011] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of a low-torque pulsating joint motor for a robot dog according to this utility model; Figure 2 This is a schematic diagram of the inclined state structure of the inclined slot of a low torque pulsating joint motor for a robot dog according to this utility model. Figure 3 This is a schematic diagram of the concentrated winding structure of a low-torque pulsating joint motor for a robot dog according to this utility model; Figure 4 This is a schematic diagram of the arched curved surface of a low-torque pulsating joint motor for a robot dog according to this utility model. Figure 5 This is a schematic diagram of the through-slot arrangement structure of a low-torque pulsating joint motor for a robot dog according to this utility model. Figure 6This is a schematic diagram of the angle adjustment mechanism of a low-torque pulsating joint motor for a robot dog according to this utility model. Figure 7 This is a system block diagram of an angle adjustment mechanism for a low-torque pulsating joint motor used in a robot dog, according to this utility model.

[0012] In the diagram: 1. Stator; 2. Rotor; 3. Mounting hole; 4. Stator slot; 5. Concentrated winding; 6. Magnet; 7. Arched surface; 8. Inclined slot; 9. Hollow shaft; 10. High-saturation ultra-thin silicon steel sheet; 11. Groove; 12. Housing; 13. Through slot; 14. Adjustment slot; 15. Adjustment rod; 16. Arc-shaped slot; 17. Arc-shaped rack; 18. Gear; 19. Gearbox; 20. Torque sensor; 21. Vibration sensor; 22. Speed ​​sensor; 23. Control module. Detailed Implementation

[0013] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0014] Example: Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, this utility model discloses a low-torque pulsating joint motor for a robot dog, comprising a stator 1 and a rotor 2. The stator 1 has mounting holes 3 for inserting the rotor 2 inside, and 24 stator slots 4 are equally spaced on the inner wall of the mounting holes 3. Each stator slot 4 contains a concentrated winding 5. 28 magnets 6 are evenly distributed on the outer side of the rotor 2. The interaction between the 28 magnetic poles and the 24 stator slots significantly optimizes the harmonic components of the air gap magnetic flux density compared to common pole-slot configurations. This pole-slot combination makes the spatial distribution of the magnetic field closer to an ideal sine wave, effectively reducing torque pulsation caused by magnetic field harmonics.

[0015] Each of the magnets 6 has an arched surface 7 on the side opposite to the mounting hole 3, and the curvature of the arched surface 7 is greater than that of the mounting hole. The arched surface 7 is used to change the shape of the magnetic pole of the magnet 6, so that the magnetic field can achieve a smoother transition in the edge region of the magnetic pole, and the spatial distribution of the magnetic flux generated by the chamfered magnet is closer to the ideal sine function shape. An unequal air gap is formed between the magnet 6 and the inner wall of the mounting hole 3 under the action of chamfering. By reducing the length of the air gap in the center region of the magnetic pole, the magnetic flux density distribution of the air gap under the magnet is closer to a sine wave, reducing harmonic components and thus reducing torque pulsation.

[0016] The stator slots 4 are inclined and arranged on the inner wall to form skewed slots 8. Based on fundamental electromagnetic principles, the interaction between the stator teeth and the rotor magnetic poles is crucial for torque generation during motor operation. However, due to the presence of the cogging structure, the relative positions of the stator teeth and rotor magnetic poles constantly change as the rotor rotates, causing a periodic change in magnetic reluctance. This results in cogging torque, leading to torque pulsation. This motor employs a skewed slot design, cleverly altering the relative positional relationship between the stator teeth and rotor magnetic poles by rotating the stator or rotor axially by a certain angle. This makes the change in magnetic reluctance smoother and more continuous, avoiding large cogging torques caused by abrupt changes in magnetic reluctance, thereby effectively reducing torque pulsation.

[0017] The stator slot 4 employs a parallel-tooth arc-shaped flat-bottom slot, which allows the air gap magnetic field distribution to more closely approximate a sine wave. Finite element analysis and other methods reveal that using this slot significantly reduces the harmonic content in the air gap magnetic field, particularly effectively suppressing low-order harmonics that cause torque ripple. Furthermore, optimized slot design, for a fractional-slot motor, provides an optimizable slot width range within which torque ripple can be minimized. The appropriate slot width for this motor was determined through simulation optimization to minimize cogging torque caused by changes in magnetic reluctance, thereby reducing torque ripple to a minimum.

[0018] The rotor 2 is provided with a hollow shaft 9, which effectively reduces the overall weight.

[0019] The inclination angle of the inclined groove 8 is a mechanical angle corresponding to one tooth pitch.

[0020] The centralized winding 5 comprises multiple layered windings 501, with an insulation layer 503 between each layered winding 501. The multiple layered windings 501 are connected in parallel. After the layered windings 501 are completed, a vacuum pressure impregnation process is used to immerse the layered windings 501 in insulating varnish. Air is removed from the layered windings 501 under vacuum, and then pressure is applied to ensure the insulating varnish fully penetrates into all gaps of the layered windings 501. This multi-layered winding design, with multiple parallel connections, allows for more precise control of the magnetic field distribution generated by the stator windings. By adjusting the current phase and magnitude of different winding layers, the magnetic field distribution can be made closer to a sinusoidal distribution, reducing harmonic content and mitigating the negative effects of magnetic field distortion, such as torque pulsation, vibration, and noise, thereby improving the smoothness and efficiency of the motor operation.

[0021] In multi-layer windings, adjacent winding layers can be isolated using insulating material, increasing the thickness and number of insulation layers, thereby effectively improving the electrical insulation strength of the windings. This is especially important for high-voltage, high-power motors, as it can prevent short-circuit faults between windings, improve the reliability and safety of the motor, and extend its service life.

[0022] Multi-layer winding design offers greater freedom to adjust winding parameters such as number of turns, wire diameter, and number of layers. The winding design can be flexibly optimized according to specific motor performance requirements, such as output voltage, current, and power factor, to achieve optimal motor performance matching, meet the needs of different application scenarios, and improve the motor's versatility and adaptability.

[0023] like Figure 5-7 As shown, the stator 1 is formed by stacking multiple high-saturation ultra-thin silicon steel sheets 10 stacked together, and insulating lubricating oil is provided between adjacent high-saturation ultra-thin silicon steel sheets 10. Several grooves 11 corresponding to the positions of stator slots 4 are provided on the high-saturation ultra-thin silicon steel sheets 10. The stator slots 4 are formed by connecting the grooves 11 on the stacked high-saturation ultra-thin silicon steel sheets 10, and the groove openings of the grooves 11 are arranged in a gradient to form inclined grooves 8.

[0024] The stator 1 is provided with an angle adjustment mechanism to adjust the tilt angle of the inclined slot 8; The angle adjustment mechanism includes a housing 12 that encloses the stator 1, and a through groove 13 recessed inward on the outer side of the high-saturation ultra-thin silicon steel sheet 10. The through grooves 13 on several stacked high-saturation ultra-thin silicon steel sheets 10 form an adjustment groove 14 with an inclination angle consistent with the inclined groove 8. The housing 12 is provided with an adjustment rod 15 inserted into one end of the adjustment groove 14 and extending out the other end. The housing 12 is also provided with a fine-tuning mechanism that adjusts the inclination of the adjustment rod. This allows for rotational adjustment of the high-saturation ultra-thin silicon steel sheet 10 to meet the requirements, thereby adjusting the angle of the adjustment groove and ultimately the angle of the inclined groove. This adjustment can be made according to different motor motion states.

[0025] The housing 12 has an arc-shaped groove 16 through which the free end of the adjusting rod 15 passes. The fine-tuning mechanism includes an arc-shaped rack 17 disposed in the arc-shaped groove and moving along the arc-shaped groove. The arc-shaped rack 17 has a through hole through which the free end of the adjusting rod 15 passes, allowing the adjusting rod to move along the through hole. The housing 12 has a gear 18 that meshes with the arc-shaped rack 17, and the housing 12 has a reduction motor 19 that drives the gear 18 to rotate. The reduction motor drives the gear to rotate, which in turn drives the arc-shaped rack 17 to move, thereby moving under the limiting action of the arc-shaped groove. This causes the high-saturation ultra-thin silicon steel sheet 10 to rotate relative to it, thereby achieving fine-tuning of the inclined groove and facilitating dynamic adjustment of the inclined groove angle.

[0026] The housing 12 is also equipped with a torque sensor 20 for detecting the load force at the shaft end of the hollow shaft 9, a vibration sensor 21 for detecting the vibration state of the motor, and a speed sensor 22 for detecting the rotational speed of the hollow shaft 9. A control module 23 is also provided on the housing 12, and the torque sensor 20, vibration sensor 21, and speed sensor 22 are all connected to the reduction motor 19 and the control module 23. At low speeds, the angle of the skew groove is increased to reduce cogging torque and vibration; at high speeds, the angle of the skew groove is decreased to improve output torque and efficiency. Under high loads, the angle of the skew groove is increased to reduce vibration and noise; under low loads, the angle of the skew groove is decreased to improve working efficiency. The vibration sensor is used to detect the vibration of the motor, thus facilitating dynamic adjustment of the skew groove angle.

[0027] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A low-torque pulsating joint motor for a robotic dog, characterized in that, It includes a stator (1) and a rotor (2); the stator (1) has an internal mounting hole (3) for the rotor (2) to be inserted, and the stator (1) has 24 stator slots (4) evenly spaced on the inner wall of the mounting hole (3), and each stator slot (4) is provided with a concentrated winding (5); the rotor (2) has 28 magnets (6) evenly distributed on the outer side; Each of the magnets (6) has an arched surface (7) on the side opposite to the mounting hole (3), and the curvature of the arched surface (7) is greater than that of the mounting hole. The arched surface (7) is used to change the shape of the magnetic pole of the magnet (6), so that the magnetic field can achieve a smoother transition in the edge region of the magnetic pole, and the magnetic flux generated by the chamfered magnet is more closely related to the ideal sine function shape in space. An unequal air gap is formed between the magnet (6) and the inner wall of the mounting hole (3) under the action of chamfering. The stator slot (4) is inclined and arranged on the inner wall to form an inclined slot (8).

2. The low-torque pulsating joint motor for a robot dog according to claim 1, characterized in that, The stator slot (4) adopts a parallel tooth arc-shaped flat bottom slot.

3. The low-torque pulsating joint motor for a robot dog according to claim 2, characterized in that, The rotor (2) is provided with a hollow shaft (9).

4. The low-torque pulsating joint motor for a robot dog according to claim 1, characterized in that, The inclination angle of the slant groove (8) is the mechanical angle corresponding to one tooth pitch.

5. A low-torque pulsating joint motor for a robotic dog according to claim 1, characterized in that, The centralized winding (5) is provided with multiple layered windings (501) arranged in layers, and an insulation layer (503) is provided between the multiple layered windings (501); the multiple layered windings (501) are arranged in parallel.

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