Direct-drive brushless torque motor of unmanned electric steering wheel

Abstract

The invention discloses an unmanned electric steering wheel direct drive brushless torque motor, which comprises a stator, a rotor and an insulation coil support, and is characterized in that the stator is provided with a mounting hole for mounting the rotor, the peripheral side of the mounting hole is provided with a plurality of mounting grooves which are arranged at equal indexing, and the rotor comprises a cylindrical 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 achieved 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] The present invention relates to the technical field related to motors, and in particular to a direct-drive brushless torque motor for an unmanned electric steering wheel. Background Art

[0002] Unmanned agricultural machinery is a type of agricultural machinery that can navigate autonomously, and has many advantages over traditional manually driven agricultural machinery. It can reduce labor costs. Unmanned driving can perform agricultural production work such as farming, sowing, and fertilizing without human operation, reducing labor costs. It can improve production efficiency. Unmanned driving can perform precise operations through intelligent control systems, avoiding repetitive operations and waste, and improving production efficiency. It can ensure the safety of farmers. Since unmanned driving can prevent people from entering dangerous areas, it can ensure the personal safety of farmers.

[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 of farmers. In the future, unmanned driving will become a new trend in agricultural production, creating more abundant food and living resources for the people.

[0004] As the core component of the steering wheel of unmanned agricultural machinery, the motor has some shortcomings in the existing technical solutions regarding its 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 larger overall size; the motor is not designed to operate in harsh and complex environments, such as rusting in a hot and humid environment; the motor itself is designed to be heavy and no weight reduction design is carried out; the motor is not designed to take mass production into consideration, resulting in high labor costs, etc. Summary of the Invention

[0005] In order to solve the defects of the prior art that the basket is large in size, occupies a large space when not in use, and is inconvenient to store the basket, the present invention provides a direct-drive brushless torque motor for an unmanned electric steering wheel.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] The present invention provides a direct-drive brushless torque motor for an unmanned electric steering wheel, comprising a stator, a rotor, and an insulating coil support, wherein the stator is provided with a mounting hole for mounting the rotor, and a plurality of mounting slots arranged at equal intervals are provided around the mounting hole. The rotor comprises a cylindrical iron core, a hollow shaft is mounted on the iron core, and a plurality of evenly distributed and inwardly recessed weight-reducing slots are provided on the outer wall of the stator, and a plurality of evenly distributed weight-reducing waist-shaped slots are provided inside the iron core, and the weight-reducing waist-shaped slots pass through both sides of the iron core and are provided on the insulating cover on the inner wall of the mounting slot; and the two insulating half-covers are clamped together by a clamping structure.

[0008] Two insulating coil supports are mounted on the upper and lower end surfaces of the stator, and windings are wound between the insulating half covers. The windings are connected in a triangle manner.

[0009] As a preferred technical solution of the present invention, the insulating coil bracket includes a bracket body, and the bracket body is provided with a first insulating sheet covering the surface of the stator, and second insulating sheets are provided on both sides of the first insulating sheet and inserted into the inner walls of the mounting groove, and the second insulating sheet is in contact with the inner wall of the mounting groove, and the first insulating sheet, the second insulating sheet and the bracket body are enclosed to form an insulating half cover covering the inside of the mounting groove; the insulating half cover is provided with a winding anti-slip side plate;

[0010] There are two insulating coil supports, which are respectively arranged on the upper and lower sides of the stator, and the insulating half covers on the two insulating coil supports are butted together to form a closed cover.

[0011] As a preferred technical solution of the present invention, the clamping structure includes a clamping socket provided at the lower end of the bracket body on an insulating coil bracket, and a clamping block provided at the lower end of the bracket body on an insulating coil bracket and clamped into the clamping socket.

[0012] As a preferred technical solution of the present invention, an end cover is also installed at the outer end of the insulating coil bracket, and the end cover is provided with a rubber expansion balloon inserted into the installation groove and in contact with the outer side walls of the two windings, and the end cover is provided with an inlet pipe and an outlet pipe connected to the inner cavity of the rubber expansion balloon; a liquid storage tank is provided in the housing of the motor, and a liquid outlet pipe is provided on the liquid storage tank, and the liquid outlet pipe is connected to the inlet pipe through a first liquid guide pipe, and a liquid inlet pipe is provided on the liquid storage tank, and the liquid inlet pipe is connected to the outlet pipe through a second liquid guide pipe, a circulation pump is provided on the first liquid guide pipe, and silicone oil is filled in the liquid storage tank.

[0013] As a preferred technical solution of the present invention, a refrigeration block is embedded on the outer wall of the liquid storage tank, and a semiconductor refrigeration plate is provided on the refrigeration block, and a heat sink is also provided on the outer wall of the liquid storage tank.

[0014] As a preferred technical solution of the present invention, the end cover is provided with a blocking block which is inserted into the mounting groove and blocks the outer wall of the rubber expansion balloon.

[0015] As a preferred technical solution of the present invention, the surfaces of the stator and rotor are electrophoretically treated so that the protective coating is evenly deposited on the surface; the hollow shaft is anodized to form a dense aluminum oxide film on the surface of the aluminum alloy.

[0016] As a preferred technical solution of the present invention, the insulating coil bracket is provided with three slots for clamping and fixing three PCB boards, and the three outlet pieces and the three-phase enameled wire connectors of the winding are welded to the PCB boards by welding.

[0017] The beneficial effects of the present invention are:

[0018] This unmanned electric steering wheel direct-drive brushless torque motor utilizes a direct-drive motor, eliminating the need for a reducer. Based on the motor's inherent design, it achieves high torque at low speeds. Furthermore, a weight-reducing design incorporates slots in the motor's stator and rotor cores to achieve a lighter motor. Compared to manual winding, this solution utilizes machine winding, a coil support, and a triangular winding connection, reducing welding heads, enabling mass production, and reducing labor costs while ensuring product consistency.

[0019] 2. This unmanned electric steering wheel direct-drive brushless torque motor is also equipped with an end cover at the outer end of the insulating coil bracket. The end cover is provided with a rubber expansion balloon inserted into the installation groove and in contact with the outer side walls of the two windings. The end cover is provided with an inlet pipe and an outlet pipe connected to the inner cavity of the rubber expansion balloon. The silicone oil in the liquid storage tank is pumped into the rubber expansion balloon through a circulating pump, so that the silicone oil circulates between the rubber expansion balloon and the liquid storage tank, and is cooled under the action of the refrigeration block on the outer wall of the liquid storage tank, thereby achieving cooling of the winding, thereby ensuring that the motor has a good heat dissipation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0021] In the attached figure:

[0022] Figure 1 This is a schematic structural diagram of a direct-drive brushless torque motor for an unmanned electric steering wheel according to the present invention;

[0023] Figure 2 This is a schematic structural diagram of a stator of a direct-drive brushless torque motor for an unmanned electric steering wheel according to the present invention;

[0024] Figure 3 It is a structural schematic diagram of a rotor of a direct-drive brushless torque motor for an unmanned electric steering wheel according to the present invention;

[0025] Figure 4 This is a structural schematic diagram of an end cover of a direct-drive brushless torque motor for an unmanned electric steering wheel according to the present invention;

[0026] Figure 5This is a schematic diagram of the installation of an end cover of a direct-drive brushless torque motor for an unmanned electric steering wheel according to the present invention;

[0027] Figure 6 This is a structural schematic diagram of an insulating coil bracket of a direct-drive brushless torque motor for an unmanned electric steering wheel according to the present invention;

[0028] Figure 7 This is a schematic diagram of the installation of a rubber expansion balloon of a direct-drive brushless torque motor for an unmanned electric steering wheel according to the present invention;

[0029] Figure 8 The diagram of the working system of the rubber expansion balloon of the direct-drive brushless torque motor of the unmanned electric steering wheel of the present invention is shown.

[0030] In the figure: 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-slip side plate; 907. Bayonet; 908. Block; 10. End cover; 11. Rubber expansion balloon; 12. Inlet pipe; 13. Outlet pipe; 14. Liquid storage tank; 15. Liquid outlet pipe; 16. First liquid guide pipe; 17. Liquid inlet pipe; 18. Second liquid guide pipe; 19. Circulation pump; 20. Refrigeration block; 21. Semiconductor refrigeration sheet; 22. Heat sink; 23. Block. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0032] Example: Figure 1-8As shown, the present invention is a direct-drive brushless torque motor for an unmanned electric steering wheel, comprising a stator 1, a rotor 2 and an insulating coil bracket 9, wherein the stator 1 is provided with a mounting hole 3 for installing the rotor 2, and the circumferential side of the mounting hole 3 is provided with a plurality of mounting slots 4 arranged at equal intervals, the rotor 2 comprises a cylindrical iron core 5, and a hollow shaft 6 is mounted on the iron core 5; the motor should preferably adopt a multi-pole structure, and the pole-slot combination adopts 24 slots and 26 poles, which increases the diameter of the rotor, and the circumferential side of the rotor 2 is provided with magnets, wherein the magnets adopt high-grade neodymium iron boron magnets and adopt a surface-mounted structure to increase the air gap magnetic density, and the stator punching sheets adopt high magnetic permeability silicon steel sheets to increase the magnetic density of the stator core teeth, increase the magnetic load, balance the electric load, and increase the effective output torque of the motor. The two sides of the magnet are provided with chamfers to change the shape of the magnetic poles of the magnet, so that the magnetic field can achieve a smoother transition in the edge area of ​​the magnetic poles, and the spatial distribution of the magnetic flux generated by the chamfered magnet is closer to the ideal sinusoidal function shape; unequal air gaps are formed between the magnet and the inner wall of the mounting hole under the action of the chamfer. The chamfering design of the magnet in the present invention is based on the basic principles of electromagnetism, and mainly involves the regulation of magnetic field distribution and magnetomotive force. When current is passed through the motor winding, magnetomotive force is generated, which interacts with the inherent magnetic field of the magnet to form an air gap magnetic field. The distribution of this magnetic field directly determines the operating characteristics of the motor. The edge magnetic field of the magnet that has not been chamfered often changes sharply, which can easily lead to uneven air gap magnetic density, generate harmonic magnetic fields, and cause adverse consequences such as torque fluctuations, vibrations, and additional losses.

[0033] By properly chopping the corners of the magnet, the shape of the magnet's pole is changed, so that the magnetic field can achieve a smoother transition in the edge area of ​​the pole. The spatial distribution of the magnetic flux generated by the chamfered magnet is closer to the ideal sinusoidal function form, effectively reducing the harmonic content. A non-uniform air gap distance is set between the magnet and the rotor or stator. By reducing the air gap length in the center area of ​​the pole, the air gap magnetic flux density in this area 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, which directly increases the output power of the motor. At the same time, due to the appropriate increase in the air gap in the edge area of ​​the pole, the distortion and leakage of the edge magnetic field are reduced, making the magnetic field distribution more reasonable, further improving the utilization efficiency of the magnetic field, and contributing to the improvement of power density.

[0034] In addition, a plurality of evenly distributed and inwardly recessed weight-reducing grooves 7 are provided on the outer wall of the stator 1, and a plurality of evenly distributed weight-reducing waist-shaped grooves 8 are provided inside the iron core 5, and the weight-reducing waist-shaped grooves 8 pass through both sides of the iron core 5. In order to achieve lightweighting of the motor, the motor has weight-reducing grooves on 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 ensure strength when outputting large torque, and avoids the magnetic field circuit, without affecting 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 insulating coil support 9 includes a support body 901, and the support body 901 is provided with a first insulating sheet 902 that covers the surface of the stator 1. The first insulating sheet 902 is provided with a second insulating sheet 903 on both sides of the inner wall of the mounting slot 4, and the second insulating sheet 903 is in contact with the inner wall of the mounting slot. The first insulating sheet 902, the second insulating sheet 903 and the support body 901 together form an insulating half-cover 904 covering the interior of the mounting slot 4; the insulating half-cover 904 is provided with a winding anti-slip side plate 905; NdFeB magnets are easily corroded by moisture, oxygen and other substances in the environment during use. After being plated with nickel-copper-nickel, the magnets can be protected from corrosion. Nickel-copper-nickel not only has good corrosion resistance, but also enhances the wear resistance of the magnets. This allows the magnets to operate in harsh environments without being affected by corrosion or wear, thereby extending their service life. Traditional solid shafts, while meeting high strength requirements, often result in a relatively large overall weight and a high moment of inertia, which limits the rapid response capability and energy efficiency of the equipment. The large-bore hollow shaft design is precisely designed to meet these challenges. Through innovative structural design, it aims to reduce weight and moment of inertia while ensuring sufficient mechanical strength of the shaft, thereby improving the overall performance of the motor and supporting mechanical structure and meeting the complex and changeable movement needs of the robot dog.

[0035] Two insulating coil supports 9 are provided, one on each side of the stator 1. The insulating half-covers 904 on the two insulating coil supports 9 are butted together to form a sealed insulating cover covering the inner wall of the mounting slot 4. The two insulating half-covers 904 are connected together by a snap-fit ​​structure. The winding is insulated by the coil supports. The coil supports are injection-molded, low-cost, and suitable for mass production. When assembled with the stator core, they simply need to be inserted into the upper and lower ends of the stator core for machine winding, resulting in a simple and labor-intensive process. The material used for the coil supports has high strength and rigidity, as well as heat resistance, wear resistance, chemical corrosion resistance, and good dimensional stability, meeting performance requirements. The coil supports feature three special slots for securing three PCBs. Assembly requires simply snapping the PCBs into the coil supports, resulting in a simple and convenient process.

[0036] Two insulating coil supports 9 are installed on the upper and lower end surfaces of the stator 1, and windings are wound between the insulating half covers 904. The windings adopt a delta connection method. The delta connection method has one less welding point than the star connection method, which reduces the labor cost of wire welding. In addition, compared with the star connection method, the delta connection method has more turns, thinner wire diameter, and fewer windings, which is convenient to manufacture and conducive to machine winding. Especially for high-speed or high-power motors, each coil has very few turns. The use of a delta connection method with a large number of turns is conducive to the flexibility of turn adjustment and wire gauge selection.

[0037] Among them, the snap-on structure includes a snap-on socket 907 at the lower end of a bracket body 901 arranged on an insulating coil bracket 9, and a block 908 at the lower end of a bracket body 901 arranged on an insulating coil bracket 9 and inserted into the snap-on socket. This makes it convenient for the two insulating coil brackets 9 to dock and is not prone to loosening or falling off during winding.

[0038] Among them, the outer end of the insulating coil bracket 9 is also equipped with an end cover 10, and the end cover 10 is provided with a rubber expansion balloon 11 inserted into the mounting groove 4 and in contact with the outer side walls of the two windings, and the end cover 10 is provided with an inlet pipe 12 and an outlet pipe 13 connected to the inner cavity of the rubber expansion balloon 11; a liquid storage tank 14 is provided in the housing of the motor, and a liquid outlet pipe 15 is provided on the liquid storage tank 14, and the liquid outlet pipe 15 is connected to the inlet pipe 12 through a first liquid guide pipe 16, and a liquid inlet pipe 17 is provided on the liquid storage tank 14, and the liquid inlet pipe 17 is connected to the outlet pipe 13 through a second liquid guide pipe 18, a circulating pump 19 is provided on the first liquid guide pipe 16, and silicone oil is contained in the liquid storage tank 14. The silicone oil in the liquid storage tank 14 is pumped into the rubber expansion balloon 11 through the circulation pump 19. In this way, the silicone oil circulates between the rubber expansion balloon 11 and the liquid storage tank 14 and is cooled by the refrigeration block 20 on the outer wall of the liquid storage tank 14, thereby cooling the winding and ensuring that the motor has a good heat dissipation effect.

[0039] Among them, a refrigeration block 20 is embedded on the outer wall of the liquid storage tank 14, and a semiconductor refrigeration plate 21 is provided on the refrigeration block 20, and a heat sink 22 is also provided on the outer wall of the liquid storage tank 14, so that the temperature can be lowered by the semiconductor refrigeration plate, thereby achieving an active cooling effect.

[0040] The end cover 10 is provided with a blocking block 23 which is inserted into the mounting groove 4 and blocks the outer wall of the rubber expansion balloon 11 .

[0041] The surfaces of the stator 1 and rotor 2 are both electrophoretically treated to uniformly deposit the protective coating. Electrophoresis allows the coating to be evenly deposited on the surface, providing strong coverage for complex shapes and small pores, protecting the core from corrosion. Furthermore, the coating is environmentally friendly, has high coating efficiency, and provides a good decorative effect. The hollow shaft 6 is anodized to form a dense aluminum oxide film on the aluminum alloy surface. This film has excellent corrosion resistance, providing better protection in humid, acidic, and alkaline environments, extending the life of the motor. The oxide film is typically harder than the aluminum alloy itself, enhancing the wear resistance and impact resistance of the hollow shaft and providing a good decorative effect.

[0042] During operation, this unmanned electric steering wheel direct-drive brushless torque motor utilizes a multi-pole structure with 24 slots and 26 poles, increasing the rotor diameter. High-grade NdFeB magnets are surface-mounted to increase air gap flux density. High-permeability silicon steel sheets are used for the stator laminations, increasing the flux density of the stator core teeth, boosting magnetic load, balancing electrical load, and increasing the motor's effective output torque. The windings are insulated using coil supports. These injection-molded coil supports are low-cost and suitable for mass production. Assembly with the stator core requires only insertion at the upper and lower ends of the stator core for machine winding, simplifying the process and minimizing labor intensity. A circulating pump 19 pumps silicone oil from the liquid reservoir 14 into the rubber expansion bladder 11, circulating the oil between the rubber expansion bladder 11 and the liquid reservoir 14. The oil is cooled by a cooling block 20 on the outer wall of the liquid reservoir 14, thereby cooling the windings and ensuring effective heat dissipation from the motor.

[0043] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A direct-drive brushless torque motor for an unmanned electric steering wheel, characterized in that: The invention comprises a stator (1), a rotor (2) and an insulating coil support (9), wherein the stator (1) is provided with a mounting hole (3) for the rotor (2) to be installed, and a plurality of mounting grooves (4) arranged at equal intervals are provided on the circumference of the mounting hole (3); the rotor (2) comprises a cylindrical iron core (5), a hollow shaft (6) is installed on the iron core (5), and a plurality of uniformly distributed and inwardly recessed weight-reducing grooves (7) are provided on the outer wall of the stator (1), and a plurality of uniformly distributed waist-shaped weight-reducing grooves (8) are provided inside the iron core (5), and the waist-shaped weight-reducing grooves (8) pass through both sides of the iron core (5); Two insulating coil supports (9) are installed on the upper and lower end surfaces of the stator (1), and windings are wound between the insulating half covers (904). The windings are connected in a triangle manner.

2. The direct-drive brushless torque motor for an unmanned electric steering wheel 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 second insulating sheets (903) are provided on both sides of the first insulating sheet (902) and inserted into the inner walls of the mounting groove (4), and the second insulating sheet (903) is fitted with the inner wall of the mounting groove, and the first insulating sheet (902), the second insulating sheet (903) and the support body (901) are enclosed to 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-slip side plate (905); Two insulating coil supports (9) are provided, and the two insulating coil supports (9) are respectively arranged on the upper and lower sides of the stator (1). The insulating half covers (904) on the two insulating coil supports (9) are butted together to form a closed insulating cover covering the inner wall of the installation groove (4); and the two insulating half covers (904) are clamped together as a whole via a clamping structure.

3. The direct-drive brushless torque motor for an unmanned electric steering wheel according to claim 1, characterized in that: The clamping structure comprises a clamping socket (907) provided at the lower end of a support body (901) on an insulating coil support (9), and a clamping block (908) provided at the lower end of the support body (901) on an insulating coil support (9) and clamped into the clamping socket.

4. The direct-drive brushless torque motor for an unmanned electric steering wheel according to claim 1, characterized in that: The surfaces of the stator (1) and the rotor (2) are both subjected to electrophoresis treatment so that the protective coating is evenly deposited on the surface; the hollow shaft (6) is subjected to anodizing treatment, and a dense aluminum oxide film is formed on the surface of the aluminum alloy during anodizing.

5. The direct-drive brushless torque motor for an unmanned electric steering wheel according to claim 1, characterized in that: The insulating coil support (9) is provided with three clamping slots (25), and the insulating coil support (9) is clamped and fixed with three PCB boards (24) through the clamping slots (25), and three outlet pieces and winding three-phase enameled wire connectors are welded to the PCB boards (24) by welding.

Images