Single-sided shaft wheel hub motor with electromagnetic brake

Abstract

This invention relates to the field of hub motor technology and discloses a single-axle hub motor with electromagnetic brake. It includes a hub with a rotor coaxially fixed inside and a stator coaxially rotatably mounted inside the rotor. A brake disc is also coaxially fixed on the hub, and a brake pad is disposed on one side of the brake disc for friction braking. An electromagnetic coil for controlling the axial movement of the brake pad is fixedly mounted on the stator. The electromagnetic coil and the brake pad are connected by an elastic structure, which presses the brake pad against the brake disc. This invention, through the synergistic effect of the electromagnetic coil and the elastic structure, achieves stable brake pad contact with the brake disc under parking lock conditions by passive pressure from the elastic structure, forming a continuous and reliable friction lock. This avoids the braking force attenuation problem caused by the reliance on continuous friction pressure in traditional structures, effectively reducing the risk of vehicle slippage.

Description

Technical Field

[0001] This invention relates to the field of hub motor technology, specifically to a hub motor with an electromagnetic brake on a single-sided axle. Background Technology

[0002] In-wheel motors are highly integrated mechatronic drive devices. By embedding the electric motor, transmission mechanism, and braking system directly within the vehicle's wheel hub, they replace the traditional vehicle's independent engine, clutch, and mechanical driveshaft structure. This achieves direct and localized power output, speed control, and braking torque application, significantly simplifying chassis layout, improving transmission efficiency, enhancing dynamic response capabilities, and supporting modular drive and intelligent braking control in electric vehicles. In-wheel motors integrate drive, braking, and load-bearing functions into a single compact unit, directly driving wheel rotation while achieving rapid response and safe parking through an electromagnetic braking mechanism.

[0003] Existing hub motors generally employ a single-mode electromagnetic brake or mechanical friction brake, simultaneously performing running braking and parking functions. For example, Chinese patent CN202421483907.3 proposes a brushless DC hub motor, which includes a hub module, a motor module, a gearbox module, and a built-in electromagnetic brake system module. The motor shaft of the motor module passes through the gearbox module and connects to the electromagnetic brake friction pad of the built-in electromagnetic brake system module. The built-in electromagnetic brake system module also includes a brake coil, a brake spring, and a brake armature. The brake spring ejects the brake armature, the brake armature limits the electromagnetic brake friction pad, and the electromagnetic brake friction pad locks the motor shaft of the motor module. When the brake coil is energized, it generates magnetism that compresses the brake spring and attracts the brake armature, causing the brake armature to detach from the electromagnetic brake friction pad, thus unlocking the motor shaft of the motor module. However, this structure has significant drawbacks. When parking, a stronger static holding force is required to resist external forces (such as slope, gravity, or collisions) and maintain a long-term lock. Traditional friction pads lack a self-locking mechanism in static scenarios and rely solely on continuous friction pressure. This makes them prone to brake force attenuation due to material creep, temperature changes, or vibration. When the external force exceeds the static friction force, it causes relative slippage between the brake disc and the friction pad, resulting in the risk of the vehicle rolling away. Furthermore, when the electromagnetic brake is de-energized, it relies solely on the elastic structure to press the brake pads together. If the magnetic circuit design or manufacturing tolerances result in insufficient residual pressing force, it will directly reduce the static locking force between the brake pads and the brake disc, thus causing the vehicle to roll away. Summary of the Invention

[0004] (I) Technical problem to be solved: In view of the shortcomings of the existing technology, the present invention provides a single-sided axle hub motor with electromagnetic brake, which has the advantages of sensitive braking during operation and stable locking force during parking braking. It solves the problem that the single friction braking mode of hub motor cannot take into account both the controllability required for dynamic braking and the rigid locking force required for static parking.

[0005] (II) Technical Solution: To achieve the above-mentioned purpose of sensitive braking during operation and stable locking force during parking brake operation, the present invention provides the following technical solution: a single-sided axle hub motor with electromagnetic brake, comprising a hub with a rotor coaxially fixedly mounted inside and a stator coaxially rotatably mounted inside the rotor. A brake disc is also coaxially fixedly mounted on the hub. A brake pad is provided on one side of the brake disc for friction braking. An electromagnetic coil for controlling the axial movement of the brake pad is fixedly mounted on the stator. The electromagnetic coil and the brake pad are connected by an elastic structure. The electromagnetic coil operates in three modes: when the electromagnetic coil is not energized, the elastic structure presses the brake pad against the brake disc; when the electromagnetic coil is energized and generates a magnetic field opposite to the magnetic pole of the brake pad, the electromagnetic coil attracts the brake pad and causes it to leave the surface of the brake disc; when the electromagnetic coil is energized and generates a magnetic field with the same magnetic pole as the brake pad, the electromagnetic coil repels the brake pad and causes it to press against the brake disc.

[0006] Preferably, the brake pad includes a friction pad that rubs against the brake disc and a brake armature that moves axially under the influence of the magnetic field of the electromagnetic coil. The brake armature is fixedly connected to the friction pad and is also fixedly connected to the elastic structure. The brake pad and the brake armature are annular. The brake armature is made of magnetic material and has an L-shaped axial cross section that is circumferentially fixed to the stator.

[0007] Preferably, the brake disc has an annular locking groove on the end face near the brake pad. A plurality of locking sliders, which can slide radially along the brake disc, are arranged circumferentially at equal intervals within the locking groove. The brake armature also has a plurality of axial meshing teeth arranged circumferentially at equal intervals. The inner diameter of the locking groove is less than or equal to the inner diameter of the meshing teeth. When the brake disc is stationary and the meshing teeth are inserted into the locking groove, the meshing teeth engage with the gaps between the plurality of locking sliders, thus circumferentially limiting the brake disc. When the brake disc rotates, the locking sliders are radially expanded outwards by centrifugal force, leaving the locking groove. At this time, the meshing teeth can no longer circumferentially limit the brake disc when re-inserting into the locking groove.

[0008] Preferably, the brake disc has a plurality of radial grooves arranged along its radial direction, the locking slider is slidably connected to the radial grooves, and a radial spring is provided between the locking slider and the radial grooves. The length of the radial groove is greater than that of the locking slider, and the locking slider slides into the radial groove when it is radially expanded outward by centrifugal force.

[0009] Preferably, a non-magnetic limiting ring is coaxially fixedly mounted on the inner ring of the brake armature. The limiting ring is circumferentially fixedly connected to the stator and axially slidably connected. The meshing teeth are fixedly disposed on the limiting ring, and a retaining ring made of magnetic material is axially slidably connected inside the limiting ring. The inner diameter of the retaining ring is larger than the outer diameter of the meshing teeth. When the retaining ring moves axially outward, it wraps around the meshing teeth. The magnetic field generated by the electromagnetic coil covers the retaining ring. A ring spring is provided between the retaining ring and the limiting ring to retract the retaining ring inside the limiting ring. The retaining ring is in phase with the magnetic pole of the brake armature. The retaining ring operates in two modes depending on the energization of the electromagnetic coil: when the magnetic field generated by the energized electromagnetic coil repulses the brake armature and the retaining ring, and the locking slider expands radially outward, the brake armature moves axially to press against the brake disc, and the retaining ring moves axially outward to insert into the locking groove, thus radially limiting the radially expanding locking slider; when the brake disc speed decreases, the electromagnetic coil is de-energized, causing the retaining ring to return to the limiting ring, and the locking slider falls back into the locking groove, thus forming a circumferential limit between the locking slider and the meshing teeth.

[0010] Preferably, the elastic structure is a press-fit magnet or a press-fit spring.

[0011] Preferably, a fixed shaft is coaxially fixedly mounted on the stator, and the electromagnetic coil is fixedly connected to the fixed shaft.

[0012] Preferably, a wheel is coaxially fixedly mounted on the hub, and a shell that rotates with the hub is fixedly mounted on the outside of the hub.

[0013] Preferably, the two ends of the hub are rotatably connected to the stator via bearings.

[0014] (III) Beneficial Effects: Compared with the prior art, the present invention provides a single-sided axle hub motor with electromagnetic brake, which has the following beneficial effects: 1. The single-sided axle hub motor with electromagnetic brake, through the combined use of electromagnetic coil structure and brake pad structure, in the parking lock state, the brake pads are stably pressed against the brake disc by the passive pressure of the elastic structure, forming a continuous and reliable friction lock, avoiding the problem of braking force attenuation caused by the reliance on continuous friction pressure in the traditional structure, and effectively reducing the risk of vehicle slippage; while in the running braking state, the dynamic switching of the electromagnetic coil magnetic field is used to achieve precise braking control, the magnetic field response is rapid and the electromagnetic force and current are linearly related, which greatly improves the sensitivity and controllability of dynamic braking. At the same time, no external power supply or additional drive mechanism is required when parking, and the preload is maintained only by the inherent characteristics of the elastic structure, which reduces energy loss and simplifies the structural complexity.

[0015] 2. This single-axle hub motor with electromagnetic brake utilizes a locking slider structure and a meshing tooth structure to change the braking mode of the brake disc based on the different energizing states of the electromagnetic coil. When the electromagnetic coil is de-energized, the elastic structure presses the brake pads against the brake disc, while the meshing teeth insert between the locking sliders, thus creating a circumferential limit on the brake disc. This shear resistance is significantly superior to the static friction of traditional friction brakes when parking and locking. Combined with the pre-tightening constraint of the radial spring on the locking slider, the static locking force is greatly enhanced, effectively resisting the risk of slippage caused by external forces such as slope and collisions. When the electromagnetic coil is energized, it generates a magnetic field that attracts the brake armature, unlocking the brake disc and allowing it to rotate freely. During the driving process, the locking slider is driven by centrifugal force. Automatic disengagement from the locking groove avoids interference with driving. During braking, the electromagnetic coil generates a magnetic field that repels the brake armature. At this time, the retaining ring inserts into the locking groove under the action of the electromagnetic coil's magnetic field, preventing the locking slider from returning to its original position due to reduced speed and interlocking with the meshing teeth, thus avoiding brake lock-up. When the brake disc speed decreases, the electromagnetic coil is de-energized, causing the retaining ring to return to the limiting ring, thereby releasing the radial limitation on the locking slider and causing it to fall back into the locking groove and form a circumferential limitation with the meshing teeth, allowing the brake disc to stop quickly. Furthermore, this method utilizes centrifugal force and magnetic field structural characteristics to achieve state switching without an additional drive mechanism, improving parking stability and ensuring the safety of the braking process, and solving the problem of insufficient coordination between parking and braking processes in traditional structures. Attached Figure Description

[0016] Figure 1 This is a three-dimensional schematic diagram of the hub structure of the single-sided axle hub motor with electromagnetic brake in this invention.

[0017] Figure 2 This is a three-dimensional schematic diagram of the housing structure of the single-shaft hub motor with electromagnetic brake in this invention.

[0018] Figure 3 This is a front view of the structure of the single-shaft hub motor with electromagnetic brake in this invention.

[0019] Figure 4 This is a cross-sectional view of the single-shaft hub motor with electromagnetic brake in this invention.

[0020] Figure 5 This is a cross-sectional view of the brake pad structure of the single-shaft hub motor with electromagnetic brake in this invention.

[0021] Figure 6 This is a diagram showing the position of the brake pads during braking by the single-sided axle hub motor with electromagnetic brake in this invention.

[0022] Figure 7 This is a schematic diagram of the brake pad structure in Embodiment 2 of the present invention.

[0023] Figure 8 This is a schematic diagram of the movement of the locking slider structure in Embodiment 2 of the present invention.

[0024] Figure 9 This is a schematic diagram of the interlocking structure between the locking slider and the meshing teeth in Embodiment 2 of the present invention.

[0025] Figure 10 This is a schematic diagram of the retaining ring structure in Embodiment 2 of the present invention to prevent the locking slider from retracting.

[0026] Figure 11 This is a schematic diagram of the three-dimensional structure of the brake pad in Embodiment 2 of the present invention.

[0027] Figure 12 This is a schematic diagram of the three-dimensional structure of the brake disc in Embodiment 2 of the present invention.

[0028] Figure 13 This is a cross-sectional view of the axial engagement of the locking slider and the meshing tooth structure in Embodiment 2 of the present invention.

[0029] In the diagram: 1. Hub; 11. Rotor; 12. Brake disc; 13. Locking groove; 14. Locking slider; 15. Radial groove; 16. Radial spring; 2. Stator; 21. Fixed shaft; 22. Electromagnetic coil; 3. Brake pad; 31. Friction pad; 32. Brake armature; 321. Limiting ring; 322. Engaging tooth; 323. Retaining ring; 324. Circular spring; 4. Elastic structure; 5. Wheel; 6. Outer shell. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1: Please refer to Figures 1-6 A single-sided axle hub motor with electromagnetic brake 1 includes a hub 1 with a rotor 11 coaxially fixed inside and a stator 2 coaxially rotatably mounted inside the rotor 11. A brake disc 12 is also coaxially fixed on the hub 1. The core purpose of the coaxial fixed mounting of the brake disc 12 and the hub 1 is to achieve direct transmission of braking torque and precise matching of rotational inertia. Through a rigid coaxial connection, such as a spline or thermocouple interference fit, the brake disc 12 and the hub 1 form an integral rotating unit, ensuring that the frictional torque is transmitted to the wheel 5 with zero delay during braking. A brake pad 3 is provided on one side of the brake disc 12 for friction braking. The brake pad 3 adopts a fan-shaped segmented assembly design, with a spring steel back plate as the base plate and a copper-based sintered composite material containing ceramic fiber and graphite as the friction material. High-temperature and high-pressure molding ensures the stability of the friction coefficient. An electromagnetic coil 22 is fixedly mounted on the stator 2 to control the axial movement of the brake pad 3. The electromagnetic coil 22 creates a high-intensity gradient of the magnetic field in the axial air gap. When the electromagnetic coil 22 is energized, its magnetic field penetrates the non-magnetic outer shell 6 and acts on the brake armature 32, overcoming the pressure of the elastic structure 4 through magnetic attraction. The electromagnetic coil 22 needs to be strictly aligned with the axial direction of the brake pad 3. The electromagnetic coil 22 and the brake pad 3 are connected by the elastic structure 4, which presses the brake pad 3 against the brake disc 12. The elastic structure 4 can provide initial clamping force during braking and reset the brake pad 3 when released. When the electromagnetic coil 22 generates a magnetic field, it attracts the brake pad 3 and causes it to leave the surface of the brake disc 12.

[0032] The elastic structure 4 is either a press-fit magnet or a press-fit spring. The elastic structure 4 exerts pressure on the brake armature 32 and is fixedly installed on one side of the electromagnetic coil 22. The press-fit magnet and the brake armature 32 have the same magnetic poles on their opposite sides. When a press-fit magnet is used, the arrangement of the press-fit magnet and the brake armature 32 with opposite poles utilizes the non-contact characteristic of magnetic repulsion to achieve pressure transmission. When the electromagnetic coil 22 is de-energized, the repulsive force of the same poles of the press-fit magnet acts on the brake armature 32, pushing the friction plate 31 to press against the brake disc 12. This avoids mechanical contact wear. The magnet is made of sintered neodymium iron boron material, with a nickel-plated surface for corrosion resistance, and the magnetic pole surfaces are precisely ground to ensure a uniform magnetic field distribution. When a press-fit spring is used, a variable pitch helical spring assembly is employed. In the small load section, it provides compliant initial pressure, while in the large deformation section, it maintains stable locking with rigidity. A fixed shaft 21 is coaxially fixedly installed on the stator 2, and the electromagnetic coil 22 is fixedly connected to the fixed shaft 21. The fixed shaft 21 serves as the heat dissipation frame and wiring channel for the electromagnetic coil 22. It is made of hollow aluminum alloy forging with axial heat dissipation fins machined on its outer surface. The coil frame is directly heat-pressed and fixed to the surface of the fixed shaft 21, achieving efficient heat conduction. High-temperature resistant polyimide insulated wires are laid inside the fixed shaft 21, connecting the stator 2 windings to an external controller. A circuit connected to the stator 2 is located inside the fixed shaft 21. A wheel 5 is coaxially fixedly mounted on the hub 1, and a housing 6 that rotates with the hub 1 is fixedly mounted on the outside of the hub 1. Both ends of the hub 1 are rotatably connected to the stator 2 via bearings.

[0033] In the parking lock state, the electromagnetic coil 22 is de-energized, and the brake pads 3 are pressed against the end face of the brake disc 12 by the axial pressure of the elastic structure 4, thereby locking the wheel hub 1. In the running braking state, the magnetic field of the electromagnetic coil 22 dynamically switches to achieve dual control: one is the driving release mode, where the electromagnetic coil 22 generates a magnetic field opposite to that of the brake armature 32, attracting the brake armature 32 to move axially, causing the friction pads 31 to disengage from the brake disc 12 and unlocking the brake disc 12; the other is the dynamic braking mode, where the electromagnetic coil 22 switches to a magnetic field with the same polarity as the brake armature 32, generating a repulsive force to push the brake armature 32 axially closer to the brake disc 12, causing the friction pads 31 to press against the surface of the brake disc 12, achieving dynamic braking through friction torque and locking the brake disc 12. Using this electromagnetic braking structure, the magnetic field response time is short, usually in the millisecond range, and the electromagnetic force is linearly related to the current magnitude, making the braking more sensitive and controllable during vehicle operation. At the same time, when the vehicle is parked, the magnetic field disappears after the electromagnetic coil 22 is de-energized, and the elastic structure 4 automatically takes effect. The pressing magnet uses the repulsive force between the like magnetic poles or the pressing spring uses the elastic deformation force of the material to continuously apply axial preload pressure to the brake armature 32, so that the friction pad 31 is pressed against the brake disc 12 with constant pressure, forming a stable friction lock. This process does not require an external power source or additional drive mechanism, and relies entirely on the passive mechanism of the elastic structure 4 to maintain the preload, avoiding energy loss and structural complexity.

[0034] Example 2: Please refer to Figures 7-13 The brake pad 3 includes a friction pad 31 that rubs against the brake disc 12 and a brake armature 32 that moves axially under the influence of the magnetic field of the electromagnetic coil 22. The brake armature 32 and the friction pad 31 are fixedly connected in a ring-shaped integrated fixed connection. When electromagnetic force or elastic force is applied to the brake armature 32, it can ensure that the friction pad 31 moves synchronously without delay. The ring structure can make the friction pressure evenly distributed. Furthermore, the brake armature 32 is fixedly connected to the elastic structure 4. The brake pad 3 and the brake armature 32 are annular. The brake armature 32 is made of magnetic material, and its axial cross-section is L-shaped and circumferentially fixed to the stator 2. An annular locking groove 13 is provided on the end face of the brake disc 12 near the brake pad 3. Several sets of locking sliders 14 that can slide radially outward along the brake disc 12 are arranged in a circumferentially equidistant array within the locking groove 13. Several sets of axial meshing teeth 322 are also arranged in a circumferentially equidistant array on the brake armature 32. The annular locking groove 13, together with the circumferentially arrayed locking sliders 14 and meshing teeth 322, constitutes a mechanical interlock between the brake pad 3 and the brake disc 12. The locking groove 13 is milled into shape on the end face of the brake disc 12, and the groove depth is slightly greater than the height of the locking sliders 14. The locking sliders 14 are made of hardened tool steel with nitriding treatment on the surface. The meshing teeth 322 are integrally forged with the brake armature 32, and the tooth shape is strengthened by powder metallurgy. When the brake disc 12 is stationary and the electromagnetic coil 22 is de-energized, the meshing teeth 322 insert into the slider gap to form a rigid circumferential constraint. The tooth sides and slider are in clearance fit, using surface contact rather than point contact to improve shear strength. When the brake disc 12 rotates, the locking slider 14 expands radially outward under centrifugal force, moving away from the locking groove 13. The brake disc 12 has several sets of radial grooves 15 arranged along its radial direction. The locking slider 14 is slidably connected to the radial grooves 15, and a radial spring 16 is provided between the locking slider 14 and the radial grooves 15. The length of the radial groove 15 is greater than that of the locking slider 14, providing centrifugal displacement space for the slider. When the locking slider 14 expands radially outward under centrifugal force, it slides into the radial groove 15.

[0035] A non-magnetic limiting ring 321 is coaxially fixedly mounted on the inner ring of the brake armature 32. The limiting ring 321 is circumferentially fixedly connected to the stator 2 and axially slidingly connected. The meshing teeth 322 are fixedly mounted on the limiting ring 321. The limiting ring 321 is made of a non-magnetic material, such as austenitic stainless steel. The limiting ring 321 and the stator 2 are circumferentially fixed by a rectangular spline. The spline groove is filled with a polytetrafluoroethylene wear-resistant layer to reduce sliding friction. The end face of the limiting ring 321 is precision ground to ensure that the perpendicularity error between the mounting plane of the meshing teeth 322 and the axis is minimal. A retaining ring 323 made of magnetic material is axially slidably connected to the limiting ring 321. The diameter of the retaining ring 323 is larger than the diameter of the meshing teeth 322, ensuring that the retaining ring 323 completely covers the root of the meshing teeth 322, forming a continuous physical structural limiting barrier. The inner diameter of the electromagnetic coil 22 is smaller than the diameter of the retaining ring 323, so that the magnetic field effectively acts on the end face of the retaining ring 323. An annular spring 324 is provided between the retaining ring 323 and the limiting ring 321 to cause the retaining ring 323 to retract inside the limiting ring 321. The annular spring 324 is made of beryllium bronze strip wound into shape and stores elastic potential energy in a pre-compressed state, so that the retaining ring 323 is defaultly retracted inside the limiting ring 321. When the magnetic field of the electromagnetic coil 22 generates a repulsive force on the retaining ring 323, the retaining ring 323 slides into the locking groove 13 along its axis and forms a radial limit on the locking slider 14 that expands outward under centrifugal force. At this time, the cylindrical surface of the retaining ring 323 and the centrifugally expanding locking slider 14 form an annular surrounding structure. The limiting function of the retaining ring 323 continues to be effective during the braking and deceleration phase until the speed returns to zero, blocking the return path of the locking slider 14 and eliminating the risk of mechanical interlocking during the braking process.

[0036] In the parking lock state, the meshing teeth 322 on the armature insert into the gap between the locking sliders 14, forming a rigid circumferential limit. Its shear strength is significantly superior to the static friction of traditional friction brakes. In this state, the locking sliders 14 are constrained within the locking groove 13 by the preload of the radial spring 16, ensuring the mechanical interlock between the meshing teeth 322 and the slider, completely resisting the risk of parking slippage caused by external forces such as slope or collision. During driving, the centrifugal force generated by the rotation of the wheel hub 1 drives the locking sliders 14 to expand outward along the radial groove 15, thereby disengaging from the locking groove 13. Figure 8 As shown. In this situation, if braking is applied, since the locking slider 14 has radially disengaged from the locking groove 13, the meshing teeth 322 can directly insert into the locking groove 13 without mechanical interlocking with the locking slider 14. Furthermore, since the electromagnetic coil 22 now has a magnetic field with the same polarity as the brake armature 32, it can not only generate a repulsive force on the brake armature 32 but also a radial repulsive force on the retaining ring 323 located within the limiting ring 321. This causes the retaining ring 323 to be radially inserted into the locking groove 13 under the repulsive force. Figure 10As shown. The design of the retaining ring 323 prevents the locking slider 14 from returning to the locking groove 13 due to the decrease in centrifugal force caused by the gradual reduction in the rotation speed of the brake disc 12 during braking. This avoids interlocking interference between the locking slider 14 and the meshing teeth 322 during the braking process. Without the retaining ring 323 to radially limit the locking slider 14, when the locking slider 14 returns to the locking groove 13 due to the decrease in centrifugal force, the locking slider 14 will mechanically lock with the meshing teeth 322, causing the brake pads 3 to lock up during braking, thus leading to safety problems. This structure effectively utilizes the centrifugal force generated by the rotation of the brake disc 12, while also efficiently utilizing the magnetic field generated by the electromagnetic coil 22. The retaining ring 323 structure can be linked with the magnetic field generated by the electromagnetic coil 22 during braking. It does not require an additional drive structure and can operate solely by utilizing the changes in the magnetic field generated by the electromagnetic coil 22. Thus, during braking, the retaining ring 323 can prevent interlocking between the locking slider 14 and the meshing teeth 322. Furthermore, during parking, it can automatically retract to interlock between the locking slider 14 and the meshing teeth 322. Compared to the brake structure, this interlocking between the locking slider 14 and the meshing teeth 322 can greatly improve the stability of the vehicle during parking.

[0037] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0038] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A single-sided hub motor with electromagnetic brake, comprising a hub (1) on which a rotor (11) is coaxially fixedly mounted, and a stator (2) rotatably mounted coaxially within the rotor (11), wherein a brake disc (12) is also coaxially fixedly mounted on the hub (1), and a brake pad (3) for friction braking is provided on one side of the brake disc (12), characterized in that: An electromagnetic coil (22) for controlling the axial movement of the brake pad (3) is fixedly mounted on the stator (2). The electromagnetic coil (22) and the brake pad (3) are connected by an elastic structure (4). The electromagnetic coil (22) operates in three modes: when the electromagnetic coil (22) is not energized, the elastic structure (4) presses the brake pad (3) against the brake disc (12); when the electromagnetic coil (22) is energized and generates a magnetic field with opposite poles to the brake pad (3), the electromagnetic coil (22) attracts the brake pad (3) and causes it to leave the surface of the brake disc (12); when the electromagnetic coil (22) is energized and generates a magnetic field with the same poles as the brake pad (3), the electromagnetic coil (22) repels the brake pad (3) and causes it to press against the surface of the brake disc (12). The brake disc (12) is described above; the brake pad (3) includes a friction pad (31) that rubs against the brake disc (12) and a brake armature (32) that moves axially under the influence of the magnetic field of the electromagnetic coil (22). The brake armature (32) is fixedly connected to the friction pad (31), and the brake armature (32) is also fixedly connected to the elastic structure (4). The brake disc (12) has an annular locking groove (13) on the end face near the brake pad (3). The locking groove (13) is circumferentially equidistantly arranged with several sets of locking sliders (14) that can slide radially along the brake disc (12). The brake armature (32) is circumferentially equidistantly arranged with several sets of axial meshing teeth (322). The inner diameter of the locking groove (13) is less than or equal to the inner diameter of the meshing teeth (322).

2. The single-sided axle hub motor with electromagnetic brake according to claim 1, characterized in that: The brake pad (3) and the brake armature (32) are annular, the brake armature (32) is made of magnetic material, and the axial cross section of the brake armature (32) is L-shaped and is circumferentially fixed to the stator (2).

3. A single-sided axle hub motor with electromagnetic brake according to claim 2, characterized in that: When the brake disc (12) is stationary and the meshing teeth (322) are inserted into the locking groove (13), the meshing teeth (322) mesh with the gaps between the locking sliders (14) to form a circumferential limit on the brake disc (12); when the brake disc (12) rotates, the locking sliders (14) are radially outwardly expanded away from the locking groove (13) by centrifugal force, and at this time the meshing teeth (322) can no longer form a circumferential limit on the brake disc (12) when they are inserted into the locking groove (13).

4. A single-sided axle hub motor with electromagnetic brake according to claim 3, characterized in that: The brake disc (12) has several sets of radial grooves (15) arranged along its radial direction. The locking slider (14) is slidably connected to the radial groove (15), and a radial spring (16) is provided between the locking slider (14) and the radial groove (15). The length of the radial groove (15) is greater than that of the locking slider (14). When the locking slider (14) is radially expanded outward by centrifugal force, it slides into the radial groove (15).

5. A single-sided axle hub motor with electromagnetic brake according to claim 3, characterized in that: A non-magnetic limiting ring (321) is coaxially fixedly mounted on the inner ring of the brake armature (32). The limiting ring (321) is circumferentially fixedly connected to the stator (2) and axially slidingly connected. The meshing teeth (322) are fixedly disposed on the limiting ring (321), and a retaining ring (323) made of magnetic material is axially slidingly connected inside the limiting ring (321). When the retaining ring (323) moves axially outward, it wraps around the meshing teeth (322). The magnetic field generated by the electromagnetic coil (22) covers the retaining ring (323). A ring spring (324) is provided between the retaining ring (323) and the limiting ring (321) to retract the retaining ring (323) inside the limiting ring (321). The retaining ring (323) has the same magnetic pole as the brake armature (32). The ring (323) is divided into two modes depending on the energization of the electromagnetic coil (22); when the magnetic field generated by the energization of the electromagnetic coil (22) generates a repulsive force on the brake armature (32) and the retaining ring (323), and the locking slider (14) expands radially outward, the brake armature (32) moves axially to press against the brake disc (12), and the retaining ring (323) moves axially outward to insert into the locking groove (13) to form a radial limit on the radially expanding locking slider (14); when the speed of the brake disc (12) decreases, the electromagnetic coil (22) is de-energized, causing the retaining ring (323) to return to the limiting ring (321), and the locking slider (14) falls back into the locking groove (13) and forms a circumferential limit between the locking slider (14) and the meshing teeth (322).

6. A single-sided axle hub motor with electromagnetic brake according to claim 1, characterized in that: The elastic structure (4) is a press-fit magnet or a press-fit spring.

7. A single-sided axle hub motor with electromagnetic brake according to claim 1, characterized in that: A fixed shaft (21) is coaxially fixedly installed on the stator (2), and the electromagnetic coil (22) is fixedly connected to the fixed shaft (21).

8. A single-sided axle hub motor with electromagnetic brake according to claim 1, characterized in that: A wheel (5) is coaxially fixedly mounted on the hub (1), and a shell (6) that rotates with the hub (1) is fixedly mounted on the outside of the hub (1).

9. A single-sided axle hub motor with electromagnetic brake according to claim 1, characterized in that: The hub (1) is rotatably connected to the stator (2) at both ends by bearings.

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