Dual-redundant electromagnetic brake

Abstract

The utility model discloses a kind of double redundancy type electromagnetic brakes, including groove disc, armature, brake disc and cover plate, groove disc is equipped with electromagnetic coil and reset compression spring and reset compression spring one end is contacted with armature, armature is located between groove disc and brake disc, brake disc is located between armature and cover plate;Electromagnetic coil includes inside coil and outside coil, inside coil is located in outside coil, the ampere-turn number of inside coil is greater than the ampere-turn number of outside coil, the inner wall of inside coil and the corresponding cavity wall between groove disc, the outer wall of inside coil and the inner wall of outside coil, the outer wall of outside coil and the corresponding cavity wall between groove disc are filled with epoxy resin respectively.The utility model is installed inside groove disc by inside and outside two electromagnetic coils, forms double redundancy design, on the one hand can increase the service life of electromagnetic brake, on the other hand can avoid the product damage and other safety accidents caused by only one electromagnetic coil sudden failure, improve the safety performance when the product such as unmanned aerial vehicle operates.

Description

Technical Field

[0001] This utility model relates to an electromagnetic brake, and more particularly to a dual-redundant electromagnetic brake based on two electromagnetic coils. Background Technology

[0002] Currently, electromagnetic brakes are widely used in various electromechanical equipment. They achieve the purpose of releasing or braking by generating an electromagnetic field through an electromagnetic coil. Their basic structure includes a slotted plate, an armature, a brake disc, and a cover plate. The slotted plate contains an electromagnetic coil and a return spring, with one end of the return spring contacting the armature. The armature is located between the slotted plate and the brake disc, and the brake disc is located between the armature and the cover plate. Their basic working principle is as follows: When the electromagnetic coil is energized, it generates a magnetic field that attracts the armature and releases the brake disc. The brake disc, located between the armature and the cover plate, can rotate freely, and the electromagnetic brake is in the released state, allowing the rotor to rotate freely. When the electromagnetic coil is de-energized, the magnetic field disappears, and the spring force of the return spring in the slotted plate pushes the armature to press the brake disc firmly against the cover plate, achieving braking. At this time, neither the brake disc nor the rotor can rotate, and the electromagnetic brake is in the braking state.

[0003] Traditional electromagnetic brakes have the following drawbacks: they have only one electromagnetic coil and no redundancy design. If the only electromagnetic coil experiences a short circuit or other abnormal operating conditions, it may cause a major accident due to the failure of the electromagnetic brake's core safety component. For example, it may cause product damage when used in products such as drones. In order to meet the reliability requirements of the application, simply installing two electromagnetic coils in the slot cannot solve this problem.

[0004] Furthermore, in applications with extremely high safety requirements, it is necessary to dynamically monitor the armature movement of the electromagnetic brake to determine whether the armature reliably releases or presses against the brake disc. This serves as the basis for judging whether the electromagnetic brake is actually in a braking state or a released state. For example, this type of electromagnetic brake with sufficient safety performance is required in the landing gear retraction devices, servos, and rotor blades of small and military drones.

[0005] To meet the aforementioned high safety performance requirements, a micro switch is typically installed on the outer wall of the tray. An adjusting screw is also installed on the edge of the armature. When the armature is attracted by the electromagnetic force generated by the electromagnetic coil and comes into contact with the tray, the adjusting screw will press against the detection part of the micro switch. The micro switch generates a detection signal and transmits it to the controller. The controller uses this signal to determine that the electromagnetic brake is actually in the released state before controlling the drone and other equipment to start operating, thus ensuring safety.

[0006] Traditional high-safety electromagnetic brakes have the following drawbacks: They rely on a single microswitch. When the armature tilts due to uneven force caused by sand or other debris, part of it may be in contact with the slotted disc while the other part remains pressed against the brake disc. In this situation, the electromagnetic brake is not fully released, representing an undesirable operating condition. If the single microswitch happens to be installed on the side where the armature contacts the slotted disc, it will send a detection signal, which the controller interprets as a released brake state, leading to a false alarm. This misjudgment poses a safety hazard and could potentially damage the drone. Furthermore, in traditional structures, the microswitch is typically fixed to the slotted disc and its position cannot be adjusted. While the adjusting screw can adjust the distance between the microswitch's detection part and the adjusting screw, the dimensional tolerances between the screw tip and the detection part are difficult to guarantee, resulting in inaccurate signal triggering, especially under harsh conditions, thus reducing detection accuracy. Utility Model Content

[0007] The purpose of this invention is to provide a dual-redundant electromagnetic brake based on two electromagnetic coils in order to solve the above-mentioned problems.

[0008] This utility model achieves the above objectives through the following technical solutions: A dual-redundant electromagnetic brake includes a slotted disc, an armature, a brake disc, and a cover plate. An electromagnetic coil and a return spring are disposed within the slotted disc, with one end of the return spring contacting the armature. The armature is located between the slotted disc and the brake disc, and the brake disc is located between the armature and the cover plate. The electromagnetic coil includes an inner coil and an outer coil, with the inner coil located within the outer coil. To make the magnetic field distribution of the two electromagnetic coils more uniform and the electromagnetic attraction on the armature more similar, the ampere-turns of the inner coil are greater than those of the outer coil. To securely mount the two electromagnetic coils, epoxy resin is filled between the inner wall of the inner coil and the corresponding cavity wall of the slotted disc, between the outer wall of the inner coil and the inner wall of the outer coil, and between the outer wall of the outer coil and the corresponding cavity wall of the slotted disc. Note: In order to achieve the start and stop control of two electromagnetic coils, the current of the corresponding circuits of the two electromagnetic coils can be monitored by the controller. This is used as the basis for judging whether there is a fault. If a fault is judged, the power supply of the first electromagnetic coil is immediately disconnected and the power supply of the other electromagnetic coil is connected to achieve the purpose of automatic switching to ensure safety. The controller is generally the controller of products such as drones. These technologies are conventional adaptive solutions and are not within the scope of protection of this application.

[0009] Preferably, in order to minimize the disadvantage of excessive difference in magnetic field distribution between the inner and outer coils due to their different positions, the distance between the inner wall of the inner coil and the corresponding cavity wall of the slot, and the distance between the outer wall of the inner coil and the inner wall of the outer coil are both 0.5-5mm and should be minimized while meeting the insulation performance requirements.

[0010] Preferably, to more reliably detect whether the armature is in close contact with the slot, multiple microswitches are evenly distributed along the circumference on the outer wall of the slot. The outer edge of the armature, corresponding to the positions of the microswitches, has protrusions extending towards the slot. The end planes of the protrusions, the surface of the armature near the slot, and the surface of the slot near the armature are parallel to each other. The microswitches are mounted on the outer wall of the slot via mounting members. Mounting plates are provided on both sides of the mounting members, each with a strip-shaped through-hole whose length is parallel to the axial direction of the central through-hole of the armature. Mounting screw holes are provided on the outer wall of the slot at positions corresponding to the strip-shaped through-holes. Multiple mounting screws pass through the corresponding strip-shaped through-holes and connect to the corresponding mounting screw holes on the outer wall of the slot. The signal output terminals of the microswitches are connected to the signal input terminals of a controller. The controller can be a controller specifically designed for this electromagnetic brake, but more often it is a controller for products such as drones. These structures are existing technologies and are not within the scope of this application.

[0011] Preferably, in order to achieve reliable detection and save product costs, the micro switch is three.

[0012] Preferably, in order to minimize the size and weight while reliably installing the micro switch, the middle part of the mounting component is a pressure plate, which is parallel to the mounting plate. The two sides of the pressure plate are bent at 90° in the same direction to form limiting plates. The two limiting plates are bent at 90° from their ends away from the center of the pressure plate to form two mounting plates. The micro switch is installed in the mounting area between the two limiting plates. The pressure plate is provided with one or more through holes.

[0013] The beneficial effects of this utility model are as follows: This invention features a dual-redundancy design by installing two electromagnetic coils, one inner and one outer, within the slot. This design allows for alternating use of the two coils during operation, increasing the lifespan of the electromagnetic brake. Furthermore, it ensures timely activation of the other coil in case of a single coil failure, preventing product damage or other safety incidents caused by the sudden malfunction of only one coil. This improves the safety performance of products such as drones. By integrating multiple (preferably three) microswitches evenly distributed along the circumference and multiple (preferably three) bosses on the armature into the electromagnetic brake, the design ensures that regardless of the direction the armature is propelled by debris during operation... Tilting causes the detection signals of multiple microswitches to become asynchronous, thus avoiding the misjudgment problem of brake release that exists in traditional structures using a single microswitch. This significantly improves the safety performance of high-safety products such as drones during operation. Furthermore, by setting a boss on the armature to form a mating structure with the microswitch, compared to traditional adjusting screws, the end face of the boss is easier to machine into a plane parallel to the plane on the side of the armature near the slot, thereby ensuring the form and position tolerance between the boss and the microswitch detection part, making the microswitch signal triggering more accurate, and thus improving detection accuracy, which is especially valuable under harsh working conditions. Attached Figure Description

[0014] Figure 1 This is a top perspective view of the dual-redundant electromagnetic brake described in this utility model; Figure 2 This is a top view of the dual-redundant electromagnetic brake described in this utility model; Figure 3 This is a front view of the dual-redundant electromagnetic brake described in this utility model. The scale of the figure is larger than [missing information]. Figure 1 and Figure 2 ; Figure 4 yes Figure 3 AA section view in the middle; Figure 5 yes Figure 4 BB section view in the middle; Figure 6 This is a bottom perspective view of the mounting component of the dual-redundant electromagnetic brake described in this utility model; Figure 7 This is a bottom-view perspective view of the armature of the dual-redundant electromagnetic brake described in this utility model. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings: like Figures 1-7As shown, the dual-redundant electromagnetic brake of this utility model includes a slotted plate 12, an armature 7, a brake disc 11, and a cover plate 4. The slotted plate 12 is provided with an electromagnetic coil and a reset spring 18, with one end of the reset spring 18 in contact with the armature 7. The armature 7 is located between the slotted plate 12 and the brake disc 11, and the brake disc 11 is located between the armature 7 and the cover plate 4. The electromagnetic coil includes an inner coil 15 and an outer coil 14. The inner coil 15 is located inside the outer coil 14. In order to make the magnetic field distribution of the two electromagnetic coils more uniform and to make the electromagnetic attraction force on the armature 7 more similar, the ampere-turns of the inner coil 15 are greater than the ampere-turns of the outer coil 14. In order to securely install the two electromagnetic coils, epoxy resin 13 is filled between the inner wall of the inner coil 15 and the corresponding cavity wall of the slotted plate 12, between the outer wall of the inner coil 15 and the inner wall of the outer coil 14, and between the outer wall of the outer coil 14 and the corresponding cavity wall of the slotted plate 12. Note: In order to achieve the start and stop control of the two electromagnetic coils, the current of the corresponding circuits of the two electromagnetic coils can be monitored by a controller (not shown in the figure) to determine whether they are faulty. If a fault is detected, the power supply of the first electromagnetic coil is immediately disconnected and the power supply of the other electromagnetic coil is connected to achieve automatic switching to ensure safety. The controller is generally the controller of products such as drones. These technologies are conventional adaptive solutions and are not within the scope of protection of this application.

[0016] like Figures 1-7 As shown, this utility model also discloses the following more optimized specific structures: To minimize the drawback of excessively different magnetic field distributions between the inner coil 15 and the outer coil 14 due to their different positions, the distance H2 between the inner wall of the inner coil 15 and the corresponding cavity wall of the slot 12, and the distance H1 between the outer wall of the inner coil 15 and the inner wall of the outer coil 14 are both 0.5-5mm and should be minimized while meeting insulation performance requirements.

[0017] To more reliably detect whether the armature 7 is in close contact with the slotted plate 12, multiple microswitches 3 are evenly distributed along the circumference on the outer wall of the slotted plate 12. At positions corresponding to the microswitches 3 on the outer edge of the armature 7, protrusions 2 are provided that extend towards the slotted plate 12. The end plane 26 of the protrusion 2, the surface 25 of the armature 7 near the slotted plate 12, and the surface of the slotted plate 12 near the armature 7 are parallel to each other. The microswitches 3 are mounted on the outer wall of the slotted plate 12 via mounting parts 1. The mounting parts 1 are located on both sides... Each mounting plate 19 has a strip-shaped through hole 20, the length of which is parallel to the axial direction of the central through hole 27 of the armature 7. The outer wall of the slot 12 has mounting screw holes corresponding to the strip-shaped through holes 20. Multiple mounting screws 8 pass through the corresponding strip-shaped through holes 20 and connect to the corresponding mounting screw holes on the outer wall of the slot 12. This allows for adjustment of the distance between the micro switch 3 and the boss 2 of the armature 7 by utilizing the fact that the length of the strip-shaped through hole 20 is greater than the outer diameter of the mounting screw 8. The signal output terminal of the micro switch 3 is connected to the signal input terminal of the controller. The controller can be a controller specifically designed for this electromagnetic brake, but more often it is a controller for products such as drones. These structures are existing technologies and are not within the scope of protection of this application.

[0018] To achieve reliable detection and save product costs, there are three microswitches.

[0019] To minimize size and weight while reliably installing the micro switch 3, the middle part of the mounting component 1 is a pressure plate 22, which is parallel to the mounting plate 19. The two sides of the pressure plate 22 are bent at 90° in the same direction to form a limiting plate 21. The positions of the two limiting plates 21 near the ends are bent at 90° away from the center of the pressure plate 22 to form two mounting plates 19. The micro switch 3 is installed in the mounting area 24 between the two limiting plates 21. The pressure plate 22 is provided with one or more through holes 23 for the protrusion of related components of the micro switch 3 (such as buttons or terminals).

[0020] Figure 1 , Figure 2 , Figure 4 and Figure 5 Also shown is a transmission cylinder 5 integrally formed with the brake disc 11 and a transmission gear 6 located inside the transmission cylinder 5. The inner wall of the transmission cylinder 5 is provided with gear teeth and meshes with the transmission gear 6. The inner wall of the transmission gear 6 is provided with a keyway for rotational transmission connection with the rotor (not shown in the figure). Figure 1 , Figure 2 and Figure 5 Also shown are connecting screws 9 for connecting the cover plate 4 and the slotted plate 12, with multiple connecting screws 9 located on the outside of the brake disc 11 and the armature 7; Figure 1 , Figure 3 and Figure 5Also shown is a limiting bushing 10 fitted over the connecting screw 9 and located between the cover plate 4 and the slotted plate 12; Figure 4 and Figure 5 Also shown is a bearing 16 mounted on the wall of the central through hole of the slotted plate 12 and a retaining ring 17 for positioning the bearing 16, which is used to rotatably connect the end of the rotor to the slotted plate 12; these structures are all conventional adaptable structures.

[0021] like Figures 1-7 As shown, during application, when products such as drones need to operate normally, either the inner coil 15 or the outer coil 14 is energized to generate an electromagnetic field, which in turn generates an electromagnetic attraction on the armature 7. This causes the armature 7 to overcome the elastic force of the reset spring 18 and approach and press against the slot plate 12. At this time, the friction plates on both sides of the brake disc 11 do not contact the cover plate 4 and the armature 7. The brake disc 11, transmission cylinder 5, transmission gear 6, and rotor are all in a free rotation state, and the electromagnetic brake is in a released braking state. At the same time, the three protrusions 2 on the armature 7 move simultaneously and contact the detection parts of the three micro switches 3, triggering the three micro switches 3 to output signals to the controller. The controller receives the signals from the three micro switches 3, determines that the electromagnetic brake is in a released braking state, and controls the motor of the drone or other products to start and operate normally.

[0022] For the inner coil 15 and the outer coil 14, the controller can reduce the continuous working time of one electromagnetic coil by using them alternately, thereby increasing the working life of the electromagnetic coil. Alternatively, when a fault such as a short circuit or open circuit is detected in one of the electromagnetic coils, the controller can immediately de-energize the electromagnetic coil and immediately energize the other electromagnetic coil, thereby avoiding safety accidents caused by electromagnetic coil failure.

[0023] However, in practical applications, some unexpected situations may arise. For example, when either the inner coil 15 or the outer coil 14 is energized to generate an electromagnetic field, a certain position of the armature 7 may be blocked by sand or other debris, preventing that side of the armature 7 from approaching the slot 12, while the other side, free of debris, can approach the slot 12 smoothly. In this case, because the three microswitches 3 are evenly distributed circumferentially, at least one or at most two of the microswitches 3's detection parts can contact the corresponding boss 2, while at least one or at most two of the microswitches 3's detection parts cannot contact the corresponding boss 2. Therefore, the controller can only receive signals from one or two microswitches 3, and cannot receive signals from all three microswitches 3. In this situation, the controller determines that the electromagnetic brake is not in a released braking state and will not control the motor of products such as drones to start, thus avoiding safety accidents caused by misjudgment. In contrast, traditional electromagnetic brakes only have one microswitch. If this situation happens to cause that microswitch to emit a signal, the controller will mistakenly interpret it as the electromagnetic brake being in a released braking state, thereby controlling the product to start and causing a safety accident.

[0024] The above embodiments are merely preferred embodiments of this utility model and are not intended to limit the technical solutions of this utility model. Any technical solution that can be implemented based on the above embodiments without creative effort should be considered to fall within the scope of protection of this utility model patent.

Claims

1. A dual-redundant electromagnetic brake, comprising a slotted disc, an armature, a brake disc, and a cover plate, wherein an electromagnetic coil and a return spring are disposed within the slotted disc, and one end of the return spring contacts the armature; the armature is located between the slotted disc and the brake disc, and the brake disc is located between the armature and the cover plate; characterized in that: The electromagnetic coil includes an inner coil and an outer coil. The inner coil is located inside the outer coil. The ampere-turns of the inner coil are greater than those of the outer coil. Epoxy resin is filled between the inner wall of the inner coil and the corresponding cavity wall of the slot, between the outer wall of the inner coil and the inner wall of the outer coil, and between the outer wall of the outer coil and the corresponding cavity wall of the slot.

2. The dual-redundant electromagnetic brake according to claim 1, characterized in that: The distance between the inner wall of the inner coil and the corresponding cavity wall of the slot, and the distance between the outer wall of the inner coil and the inner wall of the outer coil are both 0.5-5mm and should be minimized as much as possible while meeting the insulation performance requirements.

3. The dual-redundant electromagnetic brake according to claim 1 or 2, characterized in that: Multiple microswitches are evenly distributed along the circumference on the outer wall of the slot. The outer edge of the armature and the positions corresponding to the multiple microswitches are respectively provided with bosses that protrude towards the slot. The end plane of the boss, the side surface of the armature near the slot, and the side surface of the slot near the armature are parallel to each other. The microswitches are mounted on the outer wall of the slot by mounting members. Mounting plates are provided on both sides of the mounting members. The mounting plates are provided with strip-shaped through holes, and the length direction of the strip-shaped through holes is parallel to the axial direction of the central through hole of the armature. The outer wall of the slot is provided with mounting screw holes at the positions corresponding to the strip-shaped through holes. Multiple mounting screws pass through the corresponding strip-shaped through holes and are connected to the corresponding mounting screw holes on the outer wall of the slot.

4. The dual-redundant electromagnetic brake according to claim 3, characterized in that: There are three microswitches.

5. The dual-redundant electromagnetic brake according to claim 3, characterized in that: The mounting component has a pressure plate in the middle, which is parallel to the mounting plate. The two sides of the pressure plate are bent at 90° in the same direction to form a limiting plate. The two limiting plates are bent at 90° from their ends away from the center of the pressure plate to form two mounting plates. The micro switch is installed in the mounting area between the two limiting plates. The pressure plate has one or more through holes.

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