Large-bore high-density joint motor for humanoid robot
By designing a high-density articulated motor with a large inner bore, using high-grade neodymium iron boron magnets, 18 slots and 20 poles, and miniature liquid cooling components, the shortcomings of existing articulated motors in terms of high power density and lightweighting have been solved, achieving efficient operation and stability of the motor, and reducing production costs and operational difficulty.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN MAINTEX INTELLIGENT CONTROL CO LTD
- Filing Date
- 2025-06-18
- Publication Date
- 2026-06-16
AI Technical Summary
Existing joint motors have shortcomings in terms of high power density, lightweight design, and smooth operation, making it difficult to meet the development requirements of the humanoid robot market.
A high-density joint motor with a large inner diameter for humanoid robots was designed. It uses high-grade neodymium iron boron magnets, 0.2mm high-permeability silicon steel sheets, 18 slots and 20 poles, skewed slot design, same-arc magnets, multiple enameled wire windings and star connection, combined with micro liquid cooling components, to achieve real-time temperature monitoring and efficient heat dissipation.
This technology achieves high power density, lightweight design, and stable operation of the motor, avoiding overheating damage, reducing production costs and operational difficulty, and improving the reliability and efficiency of the motor.
Smart Images
Figure CN224367682U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of humanoid robot technology, specifically a high-density joint motor with a large inner hole for humanoid robots. Background Technology
[0002] Humanoid robots possess immense market potential and face significant technological challenges due to their promising development prospects. Highly autonomous and reliable robots can independently execute predetermined tasks; their near-human-like form enables better human-robot interaction, easily mimicking human activities and replacing humans in complex tasks. In military scenarios, humanoid robots, with their superior battlefield awareness, information processing, and communication capabilities, can perform high-risk missions, significantly reducing soldier workload and improving combat efficiency. In the industrial sector, humanoid robots can replace humans in complex and repetitive labor, such as quality inspection, handling, and sorting, reducing worker fatigue. Furthermore, they can serve as household assistants, performing tasks such as cooking, cleaning, and caring for the elderly and sick.
[0003] Key components of a robot include its brain, cerebellum, robotic arm, and dexterous hand, enabling it to perceive its environment, control movement, and perform tasks. The humanoid robot industry chain has upstream components such as motors and reducers, midstream humanoid robot manufacturing, and downstream system integration. As a core component of humanoid robots, motors have stringent requirements for high precision, high power, miniaturization, and lightweight design. They must reduce weight as much as possible while maintaining consistent output power to achieve lightweight and high power density, while ensuring smooth operation for high-precision control. However, existing articulated motors have design deficiencies in high power density, lightweight design, and smooth operation, making it difficult to meet the demands of the humanoid robot market. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this utility model provides a high-density joint motor with a large inner hole for humanoid robots.
[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:
[0006] This utility model discloses a high-density joint motor with a large inner bore for humanoid robots, comprising a stator and a rotor. The rotor includes a hollow shaft and magnets attached to the outer wall of the hollow shaft. The stator includes a stator core outside the magnets. Both ends of the stator core are provided with insulating end plates. The outer ends of the insulating end plates are provided with windings. One of the windings has a lead wire at its outer end. A thermal resistor is provided on the winding, and the temperature sensor of the thermal resistor is embedded inside the winding.
[0007] As a preferred technical solution of this utility model, the inner cavity of the hollow shaft is designed with a large inner hole structure, and the stator and rotor pole slots are matched with 18 slots and 20 poles.
[0008] As a preferred technical solution of this utility model, the magnet is made of high-grade neodymium iron boron magnet, the stator lamination of the stator core is made of 0.2mm high permeability silicon steel sheet, and the insulation material of the insulating end plate is made of insulation class H or above.
[0009] As a preferred embodiment of this utility model, the stator core is configured as an inclined slot.
[0010] As a preferred technical solution of this utility model, the magnet is set as a concentric arc magnet, the inner and outer arc radii of the magnet are the same, and the thickness of the magnet is equal to the offset height of the inner and outer arc centers.
[0011] As a preferred technical solution of this utility model, multiple magnets of the same arc are arranged into a single piece of material.
[0012] As a preferred embodiment of this utility model, the outer wall of the hollow shaft is provided with a spiral glue storage groove.
[0013] As a preferred embodiment of this utility model, the winding is made of multiple enameled wires.
[0014] As a preferred technical solution of this utility model, the winding is connected in a star configuration.
[0015] As a preferred embodiment of this utility model, the inner hole of the stator core is coated with iron oxide red, and the outer circle of the stator core is coated with anti-rust oil.
[0016] The beneficial effects of this utility model are:
[0017] 1. This type of humanoid robot uses a high-density joint motor with a large inner bore. By installing thermal resistors on the windings, the temperature can be monitored at all times. This allows the motor load to be adjusted according to the monitored temperature, preventing the motor from overheating and affecting normal operation.
[0018] 2. This type of humanoid robot uses a high-density joint motor with a large inner hole. The hollow shaft has a large inner hole structure, and the stator and rotor have 18 slots and 20 poles. This increases the rotor diameter and the split ratio. The use of multiple poles can reduce the magnetic thickness of the hollow shaft, thereby reducing the weight of the hollow shaft.
[0019] 3. This type of humanoid robot uses a high-density joint motor with a large inner diameter. High-grade neodymium iron boron magnets are selected for the magnets. The magnets are bonded together, reducing the air gap and increasing the air gap magnetic flux density. The stator laminations of the stator core are made of 0.2mm high-permeability silicon steel sheets, improving the magnetic flux density of the stator core teeth. The 0.2mm thickness reduces eddy current losses and increases magnetic load. The stator laminations feature an increased slot area design, and manual unwinding improves slot fill factor, reduces resistance, and increases electrical load. All insulation materials are of insulation class H or higher to ensure that the heat generated during high-load operation will not burn out the motor.
[0020] 4. This type of humanoid robot uses a high-density joint motor with a large inner hole. The optimal skew angle is calculated through simulation, which greatly reduces torque pulsation with minimal efficiency loss and makes the theoretical value of cogging torque 0.
[0021] 5. This type of humanoid robot uses a high-density joint motor with a large inner bore. The magnets are designed with the same arc radius, and the thickness of the magnet is equal to the offset height of the center of the inner and outer arcs. Compared with other magnet structures, the same arc magnet can avoid material waste and reduce the wire cutting area during wire cutting. Multiple magnets with the same arc are arranged into a single piece of material, which can save time and material during wire cutting and reduce production costs.
[0022] 6. This type of humanoid robot uses a high-density joint motor with a large inner hole. The outer wall of the hollow shaft is provided with a spiral glue storage groove, which can be used to store glue. This avoids the situation where the adhesive might be squeezed out when the magnet is attracted to the hollow shaft, thus improving the bonding strength between the hollow shaft and the magnet.
[0023] 7. This type of humanoid robot uses a high-density joint motor with a large inner diameter. The winding is made of multiple enameled wires, which reduces the wire diameter, making it easy to bend, and facilitates unwinding and shaping. This ensures the high power density of the motor and avoids the situation where using a single enameled wire may result in a thicker wire diameter, making it difficult to bend, increasing the difficulty of unwinding, and making the operator's workload high.
[0024] 8. This type of humanoid robot uses a high-density joint motor with a large inner hole. The winding is connected in a star configuration. Compared with the delta configuration, the star configuration does not have the third and third-order multiple harmonics, thus avoiding the losses and torque ripple caused by the third and third-order multiple harmonics and ensuring that the motor has low torque ripple.
[0025] 9. This type of humanoid robot uses a high-density joint motor with a large inner hole. The inner hole of the stator core is coated with iron oxide. Since the inner hole does not match other dimensions, it will not affect the installation. The outer circle of the stator core is coated with anti-rust oil. The anti-rust oil forms a thin oil film on the outer circle of the stator core, which does not affect the installation dimensions of the outer circle and ensures that the motor will not rust during long-term use. Attached Figure Description
[0026] 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:
[0027] Figure 1 This is a cross-sectional view of a high-density joint motor with a large inner hole for a humanoid robot according to this utility model.
[0028] Figure 2 This is a schematic diagram of the hollow shaft structure of a high-density joint motor with a large inner hole for a humanoid robot according to this utility model.
[0029] Figure 3 This is a cross-sectional view of the hollow shaft of a high-density joint motor with a large inner hole for a humanoid robot according to this utility model.
[0030] Figure 4 This is a star connection diagram of the winding of a high-density joint motor with a large inner diameter for a humanoid robot, according to this utility model.
[0031] Figure 5 This is a schematic diagram of the magnet structure of a high-density joint motor with a large inner hole for a humanoid robot according to this utility model.
[0032] Figure 6 This is a cross-sectional view of a micro liquid-cooled component for a high-density joint motor with a large inner bore used in a humanoid robot, according to this utility model.
[0033] In the diagram: 1. Stator; 101. Stator core; 102. Insulating end plate; 103. Winding; 104. Lead wire; 105. Resistance temperature detector (RTD); 2. Rotor; 201. Hollow shaft; 202. Magnet; 3. Miniature liquid cooling assembly; 301. Annular liquid cooling groove; 302. Annular liquid cooling pipe; 303. Liquid cooling box; 304. Water pump. Detailed Implementation
[0034] 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.
[0035] Example: Figure 1As shown, this utility model discloses a high-density joint motor with a large inner bore for humanoid robots, comprising a stator 1 and a rotor 2. The rotor 2 includes a hollow shaft 201 and a magnet 202 attached to the outer wall of the hollow shaft 201. The stator 1 includes a stator core 101 outside the magnet 202. Both ends of the stator core 101 are provided with insulating end plates 102. The outer end of the insulating end plates 102 is provided with a winding 103. One of the windings 103 has a lead wire 104 at its outer end. A thermal resistor 105 is provided on the winding 103. The temperature sensor of the thermal resistor 105 is embedded inside the winding 103. By providing the thermal resistor 105 on the winding 103, the temperature can be monitored at all times. The motor load can be adjusted according to the monitored temperature to prevent the motor from overheating and affecting normal operation. A phase change material, preferably a paraffin composite material, is embedded inside the winding 103 to balance the temperature rise through heat absorption and release, reducing the pressure of frequent adjustment of the thermal resistor 105.
[0036] Specifically, such as Figure 2 and Figure 3 As shown, the inner cavity of the hollow shaft 201 is designed with a large inner hole structure. The stator 1 and the rotor 2 have 18 slots and 20 poles. By designing the inner cavity of the hollow shaft 201 with a large inner hole structure and the stator 1 and the rotor 2 have 18 slots and 20 poles, the diameter of the rotor 2 is increased, the split ratio is increased, and the use of multiple poles can reduce the magnetic thickness of the hollow shaft, thereby reducing the weight of the hollow shaft 201.
[0037] The magnet 202 is made of high-grade neodymium iron boron magnet, the stator laminations of the stator core 101 are made of 0.2mm high-permeability silicon steel sheets, and the insulation material of the insulating end plate 102 is made of insulation class H or above. The insulating end plate 102 is impregnated to improve the insulation performance and strength of the motor. The use of high-grade neodymium iron boron magnets for the magnet 202, and the use of adhesive for the magnet 202, reduces the air gap and increases the air gap magnetic flux density. The stator laminations of the stator core 101 are made of 0.2mm high-permeability silicon steel sheets, which improves the tooth magnetic flux density of the stator core 101. The thickness of 0.2mm reduces eddy current losses and increases magnetic load. The stator laminations are designed with increased slot area and are manually rolled to improve slot fill factor, reduce resistance, and increase electrical load. All insulation materials are made of insulation class H or above to ensure that the heat generated by the motor will not burn out the motor when it is running under high load.
[0038] The stator core 101 is designed with a skewed slot. The optimal skewed slot angle is calculated through simulation, which greatly reduces torque pulsation with minimal efficiency loss and makes the theoretical value of the cogging torque zero. The stamped stator laminations are stacked into the stator core by gluing and baking using a stacking die.
[0039] Specifically, such as Figure 5As shown, the magnet 202 is configured as a concentric arc magnet, with the inner and outer arc radii being the same. The thickness of the magnet 202 is equal to the offset height of the inner and outer arc centers. Multiple concentric arc magnets are arranged into a single piece of material. By configuring the magnet 202 as a concentric arc magnet, with the inner and outer arc radii being the same and the thickness of the magnet 202 equal to the offset height of the inner and outer arc centers, compared to magnets 202 with other structures, concentric arc magnets can avoid material waste and reduce the wire cutting area during wire cutting. Arranging multiple concentric arc magnets into a single piece of material can save time and material during wire cutting, thus reducing production costs.
[0040] Specifically, such as Figure 2 and Figure 3 As shown, the outer wall of the hollow shaft 201 is provided with a spiral glue storage groove. The spiral glue storage groove on the outer wall of the hollow shaft 201 can be used to store glue, which avoids the situation where the adhesive might be squeezed out when the magnet 202 is attracted to the hollow shaft 201, thus improving the bonding strength between the hollow shaft 201 and the magnet 202.
[0041] The winding 103 is made of multiple enameled wires, which reduces the wire diameter, making it easier to bend, unwind, and shape. This ensures the high power density of the motor and avoids the situation where using a single enameled wire may result in a thicker wire diameter, making it difficult to bend, increasing the difficulty of unwinding, and causing high workload for the operator.
[0042] Specifically, such as Figure 4 As shown, the winding 103 is connected in a star configuration. Compared with the delta configuration, the star configuration does not have third and third-order multiple harmonics, thus avoiding the losses and torque ripple caused by the third and third-order multiple harmonics and ensuring that the motor has low torque ripple.
[0043] The inner hole of the stator core 101 is coated with iron oxide red, and the outer circle of the stator core 101 is coated with anti-rust oil. The iron oxide red coating on the inner hole of the stator core 101 does not affect the installation because the inner hole does not fit with other dimensions. The anti-rust oil coating on the outer circle of the stator core 101 forms a thin oil film on the outer circle of the stator core 101, which does not affect the installation dimensions of the outer circle and ensures that the motor will not rust during long-term use.
[0044] Specifically, such as Figure 6As shown, the inner wall of the hollow shaft 201 is provided with a miniature liquid cooling assembly 3. The miniature liquid cooling assembly 3 includes multiple annular liquid cooling grooves 301 provided on the inner wall of the hollow shaft 201. Annular liquid cooling pipes 302 are provided inside the annular liquid cooling grooves 301. One end of the hollow shaft 201 is provided with a liquid cooling box 303. A water pump 304 is installed on the liquid cooling box 303. The inlet of the water pump 304 is connected to the liquid cooling box 303, and the outlet of the water pump 304 is connected to the inlet of the annular liquid cooling pipes 302. The outlet of the annular liquid cooling pipes 302 is connected to the liquid cooling box 303. The liquid cooling box 303 is filled with coolant. By integrating the miniature liquid cooling assembly 3 on the inner wall of the hollow shaft 201, heat is quickly discharged through the circulating coolant, further improving the heat dissipation efficiency.
[0045] During operation, a thermal resistor 105 is installed on the winding 103 to monitor the temperature at all times. This allows for adjustment of the motor load based on the monitored temperature, preventing excessive temperature rise from affecting normal operation. Increasing the diameter of the rotor 2 and the split ratio, along with the use of a multi-pole design, reduces the magnetic thickness of the hollow shaft 201, thus reducing its weight. The insulating end plate 102 is impregnated to improve the motor's insulation performance and strength. High-grade neodymium iron boron magnets are used for the magnet 202. The adhesive-bonded nature of the magnet 202 reduces the air gap and increases the air gap magnetic flux density. The stator laminations of stator core 101 are made of 0.2mm high-permeability silicon steel sheets, which improves the magnetic density of the teeth in stator core 101. The thickness of 0.2mm reduces eddy current losses and increases magnetic load. The stator laminations feature an increased slot area design, and manual unwinding improves slot fill factor, reduces resistance, and increases electrical load. All insulation materials are of insulation class H or higher to ensure that the heat generated during high-load operation will not burn out the motor. The use of concentric arc magnets allows for waste-free wire cutting and reduces the wire cutting area. Multiple concentric arc magnets are arranged in a single array. By using a single piece of material, the wire cutting process is time-saving and material-saving, reducing production costs. The hollow shaft 201 has a spiral adhesive storage groove on its outer wall to store adhesive, preventing the adhesive from being squeezed out when the magnet 202 adheres to the hollow shaft 201. This improves the bonding strength between the hollow shaft 201 and the magnet 202. The winding 103 is made of multiple enameled wires, reducing the wire diameter and making it easier to bend, unwind, and shape. This ensures the high power density of the motor and avoids the problem of using a single enameled wire, which might result in a thicker wire diameter and make it difficult to operate. Bending increases the difficulty of unloading and makes the operation more labor-intensive. Compared with the delta connection, the star connection does not have the third and third-order multiple harmonics, avoiding the losses and torque pulsation caused by the third and third-order multiple harmonics, and ensuring that the motor has low torque pulsation. The inner hole of the stator core 101 is coated with iron oxide red. Since the inner hole does not match other dimensions, it will not affect the installation. The outer circle of the stator core 101 is coated with anti-rust oil. The anti-rust oil forms a thin oil film on the outer circle of the stator core 101, which does not affect the installation dimensions of the outer circle and ensures that the motor will not rust during long-term use.
[0046] 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 high-density joint motor with a large inner bore for a humanoid robot, comprising a stator (1) and a rotor (2), characterized in that, The rotor (2) includes a hollow shaft (201) and a magnet (202) attached to the outer wall of the hollow shaft (201). The stator (1) includes a stator core (101) outside the magnet (202). Both ends of the stator core (101) are provided with insulating end plates (102). The outer end of the insulating end plate (102) is provided with a winding (103). One of the windings (103) is provided with a lead wire (104) at its outer end. A thermal resistor (105) is provided on the winding (103). The temperature sensor of the thermal resistor (105) is embedded inside the winding (103).
2. The high-density joint motor with a large inner bore for a humanoid robot according to claim 1, characterized in that, The hollow shaft (201) has a large inner hole structure, and the stator (1) and rotor (2) have 18 slots and 20 poles.
3. The high-density joint motor with a large inner bore for a humanoid robot according to claim 1, characterized in that, The magnet (202) is made of high-grade neodymium iron boron magnet, the stator lamination of the stator core (101) is made of 0.2mm high permeability silicon steel sheet, and the insulation material of the insulating end plate (102) is made of insulation class H or above.
4. A high-density joint motor with a large inner bore for a humanoid robot according to claim 1, characterized in that, The stator core (101) is configured as an inclined slot.
5. A high-density joint motor with a large inner bore for a humanoid robot according to claim 1, characterized in that, The magnet (202) is set as a coarse-arc magnet, with the inner and outer arc radii being the same, and the thickness of the magnet (202) being equal to the offset height of the inner and outer arc centers.
6. A high-density joint motor with a large inner bore for a humanoid robot according to claim 5, characterized in that, Multiple magnets of the same arc are arranged into a single piece of material.
7. A high-density joint motor with a large inner bore for a humanoid robot according to claim 1, characterized in that, The outer wall of the hollow shaft (201) is provided with a spiral glue storage groove.
8. A high-density joint motor with a large inner bore for a humanoid robot according to claim 1, characterized in that, The winding (103) is made of multiple enameled wires.
9. A high-density joint motor with a large inner bore for a humanoid robot according to claim 8, characterized in that, The winding (103) is connected in a star configuration.
10. A high-density joint motor with a large inner bore for a humanoid robot according to claim 1, characterized in that, The inner hole of the stator core (101) is coated with iron oxide red, and the outer circle of the stator core (101) is coated with anti-rust oil.