Direct-drive brushless torque motor of unmanned electric steering wheel

Abstract

The utility model discloses an unmanned electric steering wheel direct drive brushless torque motor, which comprises a stator, a rotor and an insulation coil support, the stator is provided with an installation hole for the rotor to be installed, the periphery of the installation hole is provided with a plurality of installation grooves which are arranged in an equal indexing mode, the rotor comprises a cylindrical iron core, and the insulation coil support is arranged in the iron core. A hollow shaft is mounted on the iron core, a plurality of weight reduction grooves which are uniformly distributed and are recessed inwards are formed in the outer wall of the stator, and a plurality of uniform weight reduction waist-shaped grooves are formed in the iron core; the direct drive motor is adopted, a speed reducer is omitted, and the characteristics of low rotating speed and large torque are realized from the design of the motor. The weight reduction design is adopted, and the weight reduction grooves are formed in the stator and rotor iron cores of the motor, so that the light weight of the motor is realized; compared with manual coil inserting, according to the scheme, machine winding is adopted, a coil support is designed, a winding connection method is a triangular connection method, welding heads are reduced, batch production is achieved, labor cost is reduced, and product consistency is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, specifically to a direct-drive brushless torque motor for an unmanned electric steering wheel. Background Technology

[0002] Unmanned agricultural machinery is a type of agricultural equipment capable of autonomous navigation, offering numerous advantages over traditional manually operated machinery. It reduces labor costs, as unmanned machines can perform agricultural tasks such as plowing, sowing, and fertilizing without human intervention, thus lowering labor costs. It also improves production efficiency, as unmanned machines utilize intelligent control systems for precise operation, avoiding repetitive tasks and waste, thereby increasing productivity. Finally, it ensures farmer safety, as unmanned operation prevents personnel from entering dangerous areas, thus protecting farmers' personal safety.

[0003] The development prospects of unmanned agricultural machinery are broad. It will greatly improve the efficiency and quality of agricultural production, while also reducing the labor intensity and risks for farmers. In the future, unmanned driving will become a new trend in agricultural production, creating more abundant food and living resources for people.

[0004] As the core component of the steering wheel of unmanned agricultural machinery, the existing technical solutions for motors have some shortcomings in terms of their operating conditions and usage environment. For example, in order to achieve the characteristics of low speed and high torque, a reducer is often added to the motor, resulting in a large overall size; the motor design does not take into account operation in harsh and complex environments, such as rusting in humid and hot environments; the motor itself is designed to be heavy and no weight reduction design has been carried out; the motor design does not take into account mass production, resulting in high labor costs, etc. Utility Model Content

[0005] To address the shortcomings of existing technologies, such as the large size of the baskets, which occupy a lot of space when not in use and are inconvenient to store, this utility model provides a direct-drive brushless torque motor for an unmanned electric steering wheel.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0007] This utility model discloses a direct-drive brushless torque motor for an unmanned electric steering wheel, comprising a stator, a rotor, and an insulated coil bracket. The stator has mounting holes for the rotor, and the periphery of the mounting holes has multiple equally spaced mounting slots. The rotor comprises a cylindrical iron core with a hollow shaft mounted on it. The outer wall of the stator has multiple evenly distributed, inwardly recessed weight-reducing slots, and the interior of the iron core has multiple evenly distributed, waist-shaped weight-reducing slots. These slots penetrate both sides of the iron core and are embedded in the insulating cover of the inner wall of the mounting slots. Two insulating half-covers are snapped together by a snap-fit ​​structure.

[0008] Two insulated coil supports are mounted on the upper and lower end faces of the stator, and a winding is wound between the insulating half-covers. The winding adopts a delta connection.

[0009] As a preferred embodiment of this utility model, the insulated coil support includes a support body, and the support body is provided with a first insulating sheet covering the stator surface. Second insulating sheets are provided on both sides of the first insulating sheet and inserted into the inner walls of the mounting groove. The second insulating sheets are in contact with the inner walls of the mounting groove. The first insulating sheet, the second insulating sheet, and the support body together form an insulating half-cover inside the mounting groove. The insulating half-cover is provided with a winding anti-derailment side plate.

[0010] Furthermore, there are two insulating coil supports, which are respectively set on the upper and lower sides of the stator. The insulating half-covers on the two insulating coil supports are joined together to form a sealed cover.

[0011] As a preferred embodiment of the present invention, the snap-fit ​​structure includes a snap-fit ​​opening at the lower end of the support body on an insulated coil support, and a snap-fit ​​block at the lower end of the support body on an insulated coil support that snaps into the snap-fit ​​opening.

[0012] As a preferred embodiment of this utility model, an end cap is installed on the outer end of the insulating coil bracket, and the end cap is provided with a rubber expansion bladder that is inserted into the mounting groove and contacts the outer sidewalls of the two windings. The end cap is provided with an inlet pipe and an outlet pipe that communicate with the inner cavity of the rubber expansion bladder. A liquid storage tank is provided inside the motor housing, and an outlet pipe is provided on the liquid storage tank. The outlet pipe is connected to the inlet pipe via a first liquid guide pipe. An inlet pipe is provided on the liquid storage tank, and the inlet pipe is connected to the outlet pipe via a second liquid guide pipe. A circulation pump is provided on the first liquid guide pipe, and the liquid storage tank is filled with silicone oil.

[0013] As a preferred embodiment of the present invention, a cooling block is embedded on the outer wall of the liquid storage tank, and a semiconductor cooling chip is provided on the cooling block, and a heat sink is also provided on the outer wall of the liquid storage tank.

[0014] As a preferred technical solution of this utility model, the end cap is provided with a blocking block that is inserted into the mounting groove and blocks the outer wall of the rubber expansion bladder.

[0015] As a preferred technical solution of this utility model, the surfaces of the stator and rotor are both subjected to electrophoretic treatment to ensure that the protective coating is uniformly deposited on the surface; the hollow shaft is subjected to anodizing treatment, and a dense aluminum oxide film is formed on the aluminum alloy surface during anodizing.

[0016] As a preferred technical solution of this utility model, the insulating coil bracket is provided with three slots to secure three PCB boards, and the three lead-out pieces and the three-phase enameled wire connectors of the winding are welded to the PCB boards.

[0017] The beneficial effects of this utility model are:

[0018] 1. This type of direct-drive brushless torque motor for autonomous electric steering wheels eliminates the need for a reducer, achieving high torque at low speeds through its own design. Furthermore, weight reduction design incorporates slots in the stator and rotor cores, resulting in a lighter motor. Compared to manual production, this solution uses machine winding with a coil support and a delta connection for the windings, reducing welding points, enabling mass production, lowering labor costs, and ensuring product consistency.

[0019] 2. This type of unmanned electric steering wheel direct-drive brushless torque motor also has an end cap installed at the outer end of the insulated coil bracket. The end cap is provided with a rubber expansion bladder that is inserted into the mounting groove and contacts the outer sidewall of the two windings. The end cap is provided with an inlet pipe and an outlet pipe that communicate with the inner cavity of the rubber expansion bladder. The silicone oil in the storage tank is pumped into the rubber expansion bladder by a circulation pump, so that the silicone oil circulates between the rubber expansion bladder and the storage tank and is cooled by the cooling block on the outer wall of the storage tank, thereby cooling the windings and ensuring that the motor has a good heat dissipation effect. Attached Figure Description

[0020] 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:

[0021] Figure 1 This is a schematic diagram of the structure of a direct-drive brushless torque motor for an unmanned electric steering wheel according to this utility model;

[0022] Figure 2 This is a schematic diagram of the stator structure of a direct-drive brushless torque motor for an unmanned electric steering wheel according to this utility model.

[0023] Figure 3 This is a schematic diagram of the rotor structure of a direct-drive brushless torque motor for an unmanned electric steering wheel according to this utility model.

[0024] Figure 4 This is a schematic diagram of the structure of the end cover of the direct-drive brushless torque motor for an unmanned electric steering wheel according to this utility model.

[0025] Figure 5 This is a schematic diagram of the installation of the end cover of the direct-drive brushless torque motor for an unmanned electric steering wheel according to this utility model.

[0026] Figure 6 This is a schematic diagram of the structure of the insulated coil bracket of a direct-drive brushless torque motor for an unmanned electric steering wheel according to this utility model.

[0027] Figure 7 This is a schematic diagram of the installation of a rubber expansion bladder for a direct-drive brushless torque motor for an unmanned electric steering wheel according to this utility model.

[0028] Figure 8 This is a schematic diagram of the working system of a rubber expansion bladder for a direct-drive brushless torque motor of an unmanned electric steering wheel according to this utility model.

[0029] In the diagram: 1. Stator; 2. Rotor; 3. Mounting hole; 4. Mounting slot; 5. Iron core; 6. Hollow shaft; 7. Weight reduction slot; 8. Weight reduction waist-shaped slot; 9. Insulated coil bracket; 901. Bracket body; 902. First insulating sheet; 903. Second insulating sheet; 904. Insulating half cover; 905. Winding anti-derailment side plate; 907. Bayonet; 908. Locking block; 10. End cap; 11. Rubber expansion balloon; 12. Inlet pipe; 13. Outlet pipe; 14. Liquid storage tank; 15. Outlet pipe; 16. First liquid guide pipe; 17. Inlet pipe; 18. Second liquid guide pipe; 19. Circulating pump; 20. Cooling block; 21. Semiconductor cooling chip; 22. Heat sink; 23. Blocking block. Detailed Implementation

[0030] 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.

[0031] Example: Figure 1-8As shown, this utility model discloses a direct-drive brushless torque motor for an unmanned electric steering wheel, comprising a stator 1, a rotor 2, and an insulated coil bracket 9. The stator 1 has mounting holes 3 for the rotor 2 to be installed, and the periphery of the mounting holes 3 has multiple equally spaced mounting slots 4. The rotor 2 includes a cylindrical iron core 5, on which a hollow shaft 6 is mounted. The motor preferably adopts a multi-pole structure with 24 slots and 26 poles, which increases the diameter of the rotor. The periphery of the rotor 2 is provided with magnets, which are high-grade neodymium iron boron magnets with a surface-mount structure to increase the air gap magnetic density. The stator laminations are made of high-permeability silicon steel sheets to increase the magnetic density of the stator core teeth, improve the magnetic load, balance the electrical load, and increase the effective output torque of the motor. The magnet has chamfered edges on both sides to change the shape of the magnetic poles, allowing for a smoother transition of the magnetic field at the pole edges. This results in a spatial distribution of magnetic flux generated by the chamfered magnet that more closely resembles an ideal sinusoidal function. The chamfered edges also create unequal air gaps between the magnet and the inner wall of the mounting hole. This chamfered magnet design is based on fundamental principles of electromagnetism, primarily involving the control of magnetic field distribution and magnetomotive force. When current flows through the motor windings, a magnetomotive force is generated, interacting with the magnet's inherent magnetic field to form an air gap magnetic field. The distribution of this magnetic field directly determines the motor's operating characteristics. Without chamfering, the edge magnetic field of the magnet often exhibits abrupt changes, easily leading to uneven air gap magnetic flux density, generating harmonic magnetic fields, and causing adverse consequences such as torque fluctuations, vibrations, and additional losses.

[0032] By appropriately shaving the edges and corners of the magnets, the shape of the magnetic poles is altered, allowing for a smoother transition of the magnetic field at the pole edges. The magnetic flux generated by the shaving magnets has a spatial distribution closer to an ideal sinusoidal function, effectively reducing harmonic content. A non-uniform air gap is established between the magnets and the rotor or stator. By reducing the air gap length in the central region of the poles, the air gap magnetic flux density in that region is significantly increased, thereby enhancing the energy density of the magnetic field. This means that under the same current input, the motor can generate greater electromagnetic torque, directly increasing the motor's output power. Simultaneously, the appropriately increased air gap at the pole edges reduces distortion and leakage magnetic field at the edges, resulting in a more rational magnetic field distribution and further improving magnetic field utilization efficiency, contributing to increased power density.

[0033] Furthermore, the outer wall of the stator 1 is provided with multiple evenly distributed and inwardly recessed weight-reducing grooves 7, and the interior of the iron core 5 is provided with multiple evenly distributed weight-reducing waist-shaped grooves 8, which pass through both sides of the iron core 5. In order to achieve the weight reduction of the motor, weight-reducing grooves are opened on both the stator iron core and the rotor iron core. The design of the weight-reducing grooves takes into account the structural strength and magnetic field circuit of the motor, so that the motor can still maintain its strength when outputting high torque, and avoids the magnetic field circuit, so as not to affect the magnetic conductivity of the motor. In addition, the weight-reducing grooves also increase the heat dissipation area of ​​the motor, which is beneficial to the heat dissipation of the motor. The insulated coil support 9 includes a support body 901, on which a first insulating sheet 902 is provided covering the surface of the stator 1. Second insulating sheets 903 are provided on both sides of the first insulating sheet 902, inserted into the inner walls of the mounting groove 4. The second insulating sheets 903 are in contact with the inner walls of the mounting groove. The first insulating sheet 902, the second insulating sheet 903, and the support body 901 together form an insulating half-cover 904 covering the inside of the mounting groove 4. The insulating half-cover 904 is provided with a winding anti-detachment side plate 905. Neodymium iron boron magnets are easily corroded by moisture, oxygen, and other substances in the environment during use. Plating with nickel-copper-nickel can protect the magnets from corrosion. Nickel-copper-nickel not only has good corrosion resistance but also enhances the wear resistance of the magnets, allowing them to work in harsh environments without performance degradation due to corrosion or wear, thus extending their service life. Traditional solid shafts, while meeting high strength requirements, often result in a large overall weight and high moment of inertia, limiting the rapid response capability and energy efficiency of the equipment. The large inner bore hollow shaft design is designed to address these challenges. It aims to reduce weight and moment of inertia while ensuring sufficient mechanical strength of the shaft through innovative structural design, thereby improving the overall performance of the motor and supporting mechanical structure and meeting the complex and ever-changing motion requirements of the robot dog.

[0034] Furthermore, two insulating coil supports 9 are provided, respectively located on the upper and lower sides of the stator 1. The insulating half-covers 904 on the two insulating coil supports 9 are joined together to form a sealed insulating cover covering the inner wall of the mounting groove 4; the two insulating half-covers 904 are snapped together as one unit by a snap-fit ​​structure; the winding is insulated using the coil supports. The coil supports are injection molded, resulting in low cost and mass production capability; when assembling with the stator core, they only need to be inserted into the upper and lower ends of the stator core for machine winding, simplifying the process and reducing labor intensity; the materials used for the coil supports have high strength and rigidity, heat resistance, wear resistance, chemical corrosion resistance, and good dimensional stability, meeting the performance requirements; the coil supports have three special slot designs in their structure to fix three PCB boards, and during assembly, the PCB boards only need to be snapped into the coil supports, simplifying the process and making operation convenient.

[0035] Two insulated coil supports 9 are installed on the upper and lower end faces of the stator 1. A winding is wound between the insulating half-covers 904. The winding adopts a delta connection. The delta connection has one less solder point than the star connection, which reduces the labor cost of soldering. Moreover, the delta connection has more turns, a thinner wire diameter, and fewer windings than the star connection, which is convenient to manufacture and conducive to machine winding. Especially for high-speed or high-power motors, each coil has very few turns. Using the delta connection with more turns is conducive to the flexibility of turning number adjustment and wire gauge selection.

[0036] The snap-fit ​​structure includes a snap-fit ​​opening 907 at the lower end of the support body 901 on an insulated coil support 9, and a snap-fit ​​block 908 at the lower end of the support body 901 on an insulated coil support 9 that snaps into the snap-fit ​​opening. This facilitates the docking of two insulated coil supports 9 and prevents them from loosening or falling off during winding.

[0037] The insulating coil support 9 is equipped with an end cap 10 at its outer end. The end cap 10 has a rubber expansion balloon 11 that is inserted into the mounting groove 4 and contacts the outer sidewalls of the two windings. The end cap 10 has an inlet pipe 12 and an outlet pipe 13 that communicate with the inner cavity of the rubber expansion balloon 11. The motor housing has a liquid storage tank 14 with an outlet pipe 15. The outlet pipe 15 is connected to the inlet pipe 12 via a first liquid guide pipe 16. The liquid storage tank 14 has an inlet pipe 17, which is connected to the outlet pipe 13 via a second liquid guide pipe 18. The first liquid guide pipe 16 has a circulation pump 19. The liquid storage tank 14 is filled with silicone oil. The silicone oil in the storage tank 14 is pumped into the rubber expansion bladder 11 by the circulation pump 19. This allows the silicone oil to circulate between the rubber expansion bladder 11 and the storage tank 14, and is cooled by the cooling block 20 on the outer wall of the storage tank 14, thereby cooling the winding and ensuring that the motor has a good heat dissipation effect.

[0038] The liquid storage tank 14 is provided with a cooling block 20 embedded on its outer wall, and the cooling block 20 is provided with a semiconductor cooling chip 21. The liquid storage tank 14 is also provided with a heat sink 22. In this way, the temperature can be reduced by the semiconductor cooling chip, thereby achieving the effect of active cooling.

[0039] The end cap 10 is provided with a blocking block 23 that is inserted into the mounting groove 4 and blocks the outer wall of the rubber expansion balloon 11.

[0040] The stator 1 and rotor 2 are both electrophoretically treated to ensure uniform deposition of the protective coating. Electrophoresis provides excellent coverage for complex shapes and small pores, protecting the core from corrosion. It is also environmentally friendly, efficient, and produces a good decorative effect. The hollow shaft 6 undergoes anodizing, forming a dense aluminum oxide film on the aluminum alloy surface. This film exhibits excellent corrosion resistance, providing better protection in humid, acidic, and alkaline environments, extending the motor's service life. The hardness of the oxide film is typically higher than that of the aluminum alloy itself, improving the hollow shaft's wear resistance and impact resistance, and also providing a good decorative effect.

[0041] During operation, this type of unmanned electric steering wheel direct-drive brushless torque motor adopts a multi-pole structure with 24 slots and 26 poles, increasing the rotor diameter. High-grade neodymium iron boron magnets with a surface-mount structure are used to increase the air gap magnetic flux density. High-permeability silicon steel sheets are used for the stator laminations to increase the magnetic flux density of the stator core teeth, improve magnetic load, balance electrical load, and increase the effective output torque of the motor. The windings are insulated using coil brackets. The coil brackets are injection molded, resulting in low cost and mass production. Assembly with the stator core only requires insertion into the upper and lower ends of the stator core for machine winding, simplifying the process and reducing labor intensity. A circulating pump 19 pumps silicone oil from the reservoir 14 into the rubber expansion bladder 11, allowing the silicone oil to circulate between the rubber expansion bladder 11 and the reservoir 14. The oil is cooled by the cooling blocks 20 on the outer wall of the reservoir 14, thus cooling the windings and ensuring good heat dissipation for the motor.

[0042] 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 direct-drive brushless torque motor for an unmanned electric steering wheel, characterized in that, The stator (1), rotor (2) and insulated coil support (9) are provided. The stator (1) is provided with mounting holes (3) for the rotor (2) to be installed. The mounting holes (3) are provided with multiple equally spaced mounting grooves (4) on their periphery. The rotor (2) includes a cylindrical iron core (5). A hollow shaft (6) is installed on the iron core (5). The outer wall of the stator (1) is provided with multiple evenly distributed and inwardly recessed weight-reducing grooves (7). The interior of the iron core (5) is provided with multiple evenly distributed weight-reducing waist-shaped grooves (8). The weight-reducing waist-shaped grooves (8) pass through both sides of the iron core (5). Two insulating coil supports (9) are installed on the upper and lower end faces of the stator (1), and a winding is wound between the insulating half cover (904), the winding being connected in a delta configuration.

2. The unmanned electric steering wheel direct-drive brushless torque motor according to claim 1, characterized in that, The insulating coil support (9) includes a support body (901), and the support body (901) is provided with a first insulating sheet (902) covering the surface of the stator (1), and the first insulating sheet (902) is provided with second insulating sheets (903) on both sides of the first insulating sheet (902) inserted into the inner walls of the mounting groove (4), and the second insulating sheet (903) is in contact with the inner wall of the mounting groove, and the first insulating sheet (902), the second insulating sheet (903) and the support body (901) together form an insulating half cover (904) covering the inside of the mounting groove (4); the insulating half cover (904) is provided with a winding anti-derailment side plate (905); Furthermore, there are two insulating coil brackets (9), which are respectively set on the upper and lower sides of the stator (1). The insulating half-covers (904) on the two insulating coil brackets (9) are joined together to form a sealed insulating cover covering the inner wall of the mounting groove (4); and the two insulating half-covers (904) are snapped together as one unit by a snap-fit ​​structure.

3. The unmanned electric steering wheel direct-drive brushless torque motor according to claim 1, characterized in that, The snap-fit ​​structure includes a snap-fit ​​opening (907) at the lower end of the support body (901) on an insulated coil support (9), and a snap-fit ​​block (908) at the lower end of the support body (901) on an insulated coil support (9) that snaps into the snap-fit ​​opening.

4. The unmanned electric steering wheel direct-drive brushless torque motor according to claim 1, characterized in that, The surfaces of the stator (1) and rotor (2) are both electrophoretically treated to ensure that the protective coating is uniformly deposited on the surface; the hollow shaft (6) is anodized, and a dense aluminum oxide film is formed on the aluminum alloy surface during the anodizing process.

5. The unmanned electric steering wheel direct-drive brushless torque motor according to claim 1, characterized in that, The insulating coil bracket (9) is provided with three slots (25), and the insulating coil bracket (9) is used to fix three PCB boards (24) through the slots (25). The three lead-out pieces and the three-phase enameled wire connectors of the winding are soldered to the PCB board (24) by welding.

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