507 results about "Electromagnetic brake" patented technology

The invention discloses a vehicle control method and device and a vehicle. The method comprises the steps that in a current stroke determination period, when it is determined that an accelerator is released and a brake pedal is stepped down, the current stroke of the brake pedal is determined; if the difference value between the current stroke and the previous stroke of the previous stroke determination period is smaller than or equal to a preset difference value threshold value, the current deceleration is determined according to the current stroke, and the motor is controlled to decelerate according to the current deceleration and a proportional-integral control strategy; if the difference value between the current stroke and the previous stroke is larger than a preset difference value threshold value, or the duration of the maximum stroke of the current stroke reaches a first preset duration, an electromagnetic brake is controlled to conduct braking; and in the process of controlling the motor to decelerate, if the duration of the opposite actual rotation direction of the motor to the initial rotation direction reaches a second preset duration, updating the proportional-integral control strategy, and controlling the motor to operate according to the updated proportional-integral control strategy. According to the technical scheme, the vehicle can be better controlled.

The invention relates to the technical field of friction materials, and particularly discloses an electromagnetic brake friction material prepared from granules and a preparation process of the electromagnetic brake friction material in order to solve the problem that an existing electromagnetic brake friction plate is difficult to prepare or insufficient in performance. The reinforcing material comprises plasma modified aramid pulp, coupling modified composite mineral fibers, SiO2 coated tetrapod-like zinc oxide whiskers and carbon fiber-aluminum silicon whiskers; the filler comprises modified needle-like wollastonite and organic modified precipitated barium sulfate; the adhesive comprises boron-silicon synergistic modified phenolic resin and modified carboxy nitrile rubber. The raw materials are improved, and granules are prepared by adopting a mixing and crushing process, so that the content of an adhesive can be greatly reduced, meanwhile, the die filling efficiency can be improved, the die thickness and the high-temperature heat fading of the friction material can be reduced, a cold press molding process can be omitted, and the qualification rate of finished friction materials can be improved.

The invention provides a medical CT hospital bed vertical lifting mechanism and a medical CT hospital bed, the medical CT hospital bed vertical lifting mechanism comprises a top plate, a shear fork mechanism, a driving system, a base, a detection device and a limiting device, the driving system comprises a rigid chain, a worm gear reducer, a servo motor and an electromagnetic brake, and the output end of the servo motor is connected with the worm gear reducer; the output end of the worm gear reducer is connected with the rigid chain, the electromagnetic brake is connected with a driving shaft of the rigid chain, the top plate is driven by the rigid chain to move up and down, and the detection device is used for monitoring the height of the top plate. The top plate and the base are each provided with a guide device matched with the shear fork mechanism. The limiting device comprises a mechanical limiting device and an electric limiting device. A dual-mode safety system with worm and gear self-locking and electromagnetic braking is adopted, so that the sickbed can be prevented from falling under extreme working conditions such as power failure, and dual guarantee of dynamic and static safety can be realized; and the safety of equipment and personnel is guaranteed through a triple protection framework of electric limiting and mechanical limiting.

The utility model relates to the technical field of electromagnetic brake production, in particular to electromagnetic brake friction surface machining equipment which comprises a workbench, a supporting frame, an electric guide rail, a clamping assembly and a polishing assembly, the upper end face of the workbench is connected with the supporting frame, a groove is formed in the workbench, and the electric guide rail is connected into the groove; the clamping assembly is connected to the moving end of the electric guide rail, and the grinding assembly is connected to the supporting frame. According to the friction plate clamping device, when the clamping ends of the clamping assembly are in the use state, the multiple clamping ends can synchronously move towards the circle center position, friction plates to be machined are clamped and fixed through movement of the multiple clamping ends, meanwhile, when the friction plates with different thicknesses are machined, the height of the moving end in the height adjusting assembly can be adjusted, and the friction plates with different thicknesses can be clamped and fixed. And after the height of the moving end is changed, the height of the clamping end is also changed, so that the situation that the clamping end is higher than the friction plate to affect normal grinding is prevented.

The invention discloses a high-stability electromagnetic brake convenient to disassemble and assemble, and relates to the technical field of brakes. Comprising a shell, a base is installed on the top of the shell through a connecting shaft, a rotating shaft channel is formed between the base and the top of the shell in a penetrating mode, an armature is arranged on the portion, located on the surface of the rotating shaft channel, between the base and the shell in a sleeving mode, an electromagnetic coil is arranged in the shell, and an installation mechanism is arranged at the bottom of the shell. A compensation assembly is arranged at the top of the armature, a rotating disc is rotationally connected to the position, located on the surface of the periphery of the rotating shaft channel, in the cavity in the device shell, a connecting rod is arranged in the armature in a limiting mode, an unlocking assembly is arranged at the bottom of the shell, and the armature and the shell are installed easily and can be operated by one person; gaps in all directions between the armature and the electromagnetic coil are ensured to be the same, adjustment is easy, and automatic compensation after the brake pad is abraded is achieved.

The utility model discloses a duplex winding electromagnetic brake which comprises a first winding, a second winding, a static iron core and a movable iron core, the first winding and the second winding are wound on the static iron core, a spring is arranged between the static iron core and the movable iron core, the static iron core is fixedly connected with a fixed plate assembly, and an internal spline is arranged between the movable iron core and the fixed plate assembly. The inner spline is located in the center of the outer spline and meshed with the outer spline, the outer spline can be fixedly connected with a motor rotating shaft, the braking effect on the motor is achieved, after the first winding or the second winding is powered on, a winding coil generates electromagnetic force, the movable iron core and the static iron core can be attracted, and the unlocking function is achieved. According to the utility model, the two sets of windings not only improve the reliability of electromagnetic braking and ensure reliable unlocking, but also are wound on the same static iron core and share one magnetic circuit, so that the space can be saved.

The utility model provides an electromagnetic brake convenient for heat dissipation, which comprises a heat dissipation assembly, and the heat dissipation assembly is arranged at the lower part of an electromagnetic brake body and comprises a fixed seat and a plurality of groups of heat dissipation fins; the radiating fins can absorb heat generated in the braking process and discharge the heat, the radiating area can be increased by arranging the multiple sets of radiating fins, the heat can be effectively transmitted to the external environment, and the phenomenon of overheating caused by accumulation of the generated heat in the electromagnetic brake body is avoided; the electromagnetic brake body can be kept within a proper working temperature range, the operation stability of the electromagnetic brake body is guaranteed, and the service life of the electromagnetic brake is prolonged.

A frame is provided for an actuator assembly of a vehicle brake having a housing enclosing a gear stage and a motor for delivering torque to the gear stage. The frame includes a base having a first interface for connecting to the gear stage and a second interface for connecting to the motor. Projections extend outward from the first interface for receiving fasteners to secure the base directly to the housing and transfer loads from the motor to the housing during braking operations.

The invention relates to the field of brakes, in particular to a double-disc type electromagnetic-EMB composite brake and a control strategy thereof. The invention innovatively designs a double-disc type electromagnetic-EMB composite brake with a compact structure aiming at an EMB braking structure widely adopted by a distributed driving electric vehicle. According to the brake, the electromagnetic brake is embedded into an original friction disc, and organic combination of friction braking and electromagnetic braking is achieved. Based on the hybrid control theory, the invention designs a mode switching control strategy of the composite braking system. The method comprises the following steps of: modeling each system by utilizing MATLAB / Simulink, and setting different simulation working conditions; simulation results show that the electromagnetic-friction-regeneration composite braking structure has good feasibility, and comparative analysis under different working conditions further proves the rationality of hybrid automaton control strategy design.

The invention relates to the technical field of electromagnetic brakes, in particular to an electromagnetic hydraulic braking structure and electric control electromagnetic hydraulic braking calipers. The electromagnetic hydraulic braking structure comprises a combined piston assembly, the combined piston assembly comprises a piston cylinder, the piston cylinder is provided with a first piston cavity and a second piston cavity which are communicated with each other, the first piston cavity is provided with a combined outer piston and a combined inner piston in a penetrating mode, and the second piston cavity is provided with a pressurizing small plunger in a penetrating mode; an oil storage cavity is formed outside the piston cylinder, and a plurality of oil holes are formed in the side wall of the piston cylinder and are communicated with the first piston cavity and the oil storage cavity; the electromagnet assembly comprises an armature, and the armature abuts against the combined inner piston; and the hydraulic braking assembly is internally provided with an oil way and communicates with the second piston cavity, and multi-stage pressure amplification is achieved through double-cavity linkage. Gap fluctuation between the brake pad and the brake disc in the braking process can be effectively controlled, the characteristic of large suction force of the tail end of the electromagnet is efficiently utilized, and meanwhile the stable braking effect is achieved.

The invention is suitable for the technical field of brakes, and provides an energy-saving electromagnetic brake which comprises a stator and a flange plate, and a rotor capable of being matched with a target transmission shaft to synchronously rotate and an armature controlled by a coil and a spring are arranged in a gap between the stator and the flange plate; the spring can push the armature to be away from the stator so that the armature can abut against the friction plate for braking. The coil can attract the armature to approach the stator to separate the armature from the friction plate to cancel braking; a release plate used for limiting the armature is installed on the side, close to the flange plate, in the gap. The brake is provided with an external matching mechanism capable of controlling the release plate to limit or cancel limit of the armature, and the external matching mechanism adopts a push-pull type electromagnet. Therefore, the device can be kept in an open state without being electrified for a long time in an equipment operation working condition, so that unnecessary energy loss is reduced.

The invention discloses an integrated coil framework structure for an electromagnetic brake coil and a preparation method, the integrated coil framework structure comprises a coil wire spool and an integrated plug-in device, and the integrated plug-in device is vertically provided with a terminal accommodating cavity A and a terminal accommodating cavity B side by side towards a wire winding space; a wire passing clamping groove A is transversely formed in the upper portion of the terminal containing cavity A in a penetrating mode, a wire passing clamping groove B is transversely formed in the upper portion of the terminal containing cavity B in a penetrating mode, enameled wires are correspondingly wound in the winding space of the coil winding disc, and an inner connecting terminal A is inserted into the terminal containing cavity A in a matched mode. The first end of the enameled wire transversely penetrates through the wire passing clamping groove A and is electrically connected with the inner connecting terminal A inserted into the terminal containing cavity A. The inner connecting terminal A is provided with an external terminal inserting groove A. According to the invention, the integrated plugging device is formed and constructed on the end side of the coil wire spool, and through the integrated plugging device, centralized and accurate tightening and positioning of the starting end and the tail end of the enameled wire wound on the coil wire spool and riveting type tight positioning and electric connection of the inner connecting terminal and the enameled wire are realized.

The application discloses a kind of wind turbine yaw system electromagnetic brake online monitoring method, comprising the following steps: S1, the current data of electromagnetic brake output in the automatic yaw operation process of wind turbine is collected;S2, in the preset acquisition module of wind turbine nacelle control cabinet, the current data collected is transmitted to the computing device in the tower base of wind turbine by acquisition module;S3, the current data is analyzed in real time by the internal program of computing device, and the deviation degree of electromagnetic brake current is calculated, the running state of wind turbine yaw system electromagnetic brake is judged according to the deviation degree, and the running state is fed back to the main control of wind turbine;The application can monitor the health status of yaw system in real time online, ensure that unit safe and stable operation, find electromagnetic brake action failure condition in advance, effectively reduce the replacement maintenance cost caused by yaw subcomponent damage, and avoid long stop risk caused by unit maintenance process.

The embodiment of the invention relates to the technical field of vehicle control, and discloses a vehicle door hovering control method and device and a computer readable storage medium. According to the embodiment of the invention, the motion state and trend of the vehicle door can be accurately obtained by detecting the motion characteristics of the vehicle door at the moment before hovering. Then, according to the feature range of the motion features, target equipment used for controlling the vehicle door to hover and corresponding working parameters are determined; therefore, the control strategy can be accurately adjusted according to specific conditions, and the problem caused by intervention of a single power supply driver and an electromagnetic brake is avoided. And a control instruction is generated based on the determined working parameters and sent to the target equipment, and the target equipment controls the vehicle door according to the working parameters. In this way, fine control over the vehicle door hovering process can be achieved, and shaking and abnormal sound during sudden stop are reduced. Meanwhile, due to the fact that control is more accurate, the force needed when the external force is started again can be correspondingly reduced, and the opening and closing experience of the electric vehicle door is improved.

This utility model discloses a simulation device for testing the functional interface circuits of a simulating mobility scooter. It includes a controller with various functional interfaces, a plastic housing for testing the simulation interfaces, and a circuit board for interface simulation control connectors. A power enable switch, a simulated manual brake switch, an electromagnetic brake switch, a speed switching mode switch, a speed control potentiometer, an adjustable resistor mounting position, a horn, a working status indicator light, and CAN converter connector terminals are all electrically connected to the interface simulation control connector circuit board. The controller connector terminals are electrically connected to the controller with its various functional interfaces via an adapter cable. The working status indicator light is used to detect and indicate whether the operation is normal. This device simplifies and reduces the cost of testing the controller's functional interfaces and allows for simulated monitoring of the lifespan of the simulating mobility scooter's functions after functional testing.

The application discloses a kind of passive and active hybrid controllable joint assisted buffering device for wearable exoskeleton.It includes joint upper and lower connecting rod, gyro angle sensor, power mechanism and upper and lower connecting rod binding mechanism;Power mechanism includes motor, electromagnetic clutch, electromagnetic brake, buffering mechanism, gear transmission mechanism;When active assistance, buffering mechanism and joint lower connecting rod are isolated by electromagnetic brake, active flexion / extension movement of joint is realized by motor and electromagnetic clutch, and joint energy is enhanced;When passive buffering, motor and joint are isolated by electromagnetic clutch, passive torque force is transmitted to joint movement by buffering mechanism through gear transmission mechanism by electromagnetic brake.The application can realize active assistance of human joint by controlling the on-off of clutch and brake, does not hinder joint free movement without assistance, can introduce buffering to protect joint and motor in sudden situation such as falling, and has better man-machine cooperation and wearing safety.

The application discloses a kind of wind generating set electromagnetic brake splines dismounting device and dismounting method, for dismounting spline;The dismounting device includes two thrust blocks, two sliders, two fixed blocks and two adjusting screws;Two thrust blocks are respectively arranged in the opposite sides of the top of yaw motor end cover of wind generating set, and are respectively located in the opposite sides of spline;The side of each thrust block towards spline is formed with a limit structure, and the top surface of the side of thrust block towards spline is wedge surface;The side of each thrust block away from spline is formed with mounting groove;Two sliders are respectively installed in the mounting groove of two thrust blocks;Two fixed blocks are detachably installed in the opposite sides of the top of yaw motor end cover, and are respectively located outside two sliders;Two adjusting screws are respectively connected with two fixed blocks in one-to-one correspondence in horizontal direction by screw thread.This application can effectively solve the problems of limited spline dismounting space, poor centering effect, easy damage to components, insufficient universality and the like.

The invention relates to an eVTOL nacelle tilting steering engine based on high reduction ratio transmission and a working method, and relates to the field of electric vertical take-off and landing aircrafts. According to the technical scheme, the design that the double-cycloid speed reducer is combined with the parallel shaft speed reduction gear set is adopted, the wiring harness passing ability problem from the aircraft end to the nacelle is solved, the single-point failure risk that a lead screw of a traditional linear steering engine is stuck is avoided, and the safety and reliability of the steering engine are improved; moreover, depending on the dual-redundancy winding, the dual-redundancy electromagnetic brake and the dual-redundancy rotating speed feedback of the dual-redundancy servo motor, the dual-redundancy design is realized from the electrical level, and the safety performance is further enhanced. In addition, external disturbance can be reduced through high-reduction-ratio transmission, the influence of aerodynamic load disturbance on nacelle actuation is reduced, and the tilting stability is greatly improved.

The utility model provides a three-station motor control system. The three-station motor control system comprises a power supply module, a station detection module, a main control module, a first driving module, a second driving module and a man-machine interaction module, the power supply module is used for supplying power; the station detection module is used for detecting the station state of the three-station main switch and sending a station detection signal to the main control module; the main control module controls the corresponding action of the motor through the first driving module and controls the corresponding action of the electromagnetic brake through the second driving module according to the station detection signal; the motor is used for driving the three-station main switch to perform station switching; the electromagnetic brake is used for braking the motor; according to the utility model, the station state of the three-station main switch can be detected in real time, so that the main control module can control the motor and the electromagnetic brake to perform corresponding actions, and the station state of the three-station main switch can be displayed.

To provide a brake control circuit that can eliminate a time lag from the start of power supply to the start of voltage application to a coil of a non-excitation actuated electromagnetic brake even though it is possible to reduce the power consumption when the electromagnetic brake is in the released state.SOLUTION: When power supply to a brake control circuit 4 is started, the brake control circuit 4 applies, to a coil 3, a first voltage which is a DC voltage that releases an electromagnetic brake and is an input voltage to the brake control circuit 4 for a predetermined time, and then applies, to the coil 3, a second voltage which is a DC voltage that maintains the released state of the electromagnetic brake, and starts the application of the first voltage to the coil 3 in synchronization with the start of power supply. Further, the brake control circuit 4 stops a first drive signal for generating the first voltage when a predetermined time elapses after the start of power supply, and starts to generate a second drive signal to generate the second voltage before the first drive signal is stopped.SELECTED DRAWING: Figure 4

The utility model discloses a warm-keeping and cooling device for traditional Chinese medicinal material planting, and relates to the technical field of traditional Chinese medicinal material planting. The warm keeping and cooling device for traditional Chinese medicinal material planting comprises a support, a temperature adjusting mechanism and a height mechanism, the temperature adjusting mechanism comprises a protection assembly arranged on the support and an adjusting assembly arranged in the support, the protection assembly is connected with the adjusting assembly in a clamped mode, a conveying box is arranged on the protection assembly, and an electromagnetic brake is fixedly connected to the conveying box. The height mechanism comprises a C-shaped fixing frame arranged on the support and a guide rod arranged on the C-shaped fixing frame, and the bottom of the inner side of the C-shaped fixing frame is fixedly connected with the guide rod. According to the mechanism, the constant-temperature heating rod is additionally arranged and matched with the fan for use, so that temperature rise adjustment can be conducted, the low-temperature environment can be improved, the situation that medicinal materials are frozen to death is avoided, in addition, the fan can prevent the situation that the temperature rise of the constant-temperature heating rod is too high, meanwhile, the protection assembly plays a role in protecting the adjusting assembly, and entering of dust and topsoil can be reduced.

The invention provides a cable rapid winding machine for cable processing, and belongs to the technical field of cable processing, the cable rapid winding machine comprises a base, a rapid circulation assembly and a rapid cylinder changing assembly, the rapid circulation assembly comprises a rotating rod rotatably connected to the interiors of two supporting plates, and the outer wall of the rotating rod is provided with a connecting cylinder; the cable winding device has the beneficial effects that during use, after one winding drum is fully wound with a cable, a controller opens an electric telescopic rod, the electric telescopic rod drives a connecting frame to move, the connecting frame drives a torque motor and a rhombic head to move, the rhombic head slides out of one rhombic groove, at the moment, the controller opens an electromagnetic brake motor, and the electric telescopic rod drives the connecting frame to move; the rotating rod rotates to drive the connecting cylinder to rotate, the connecting cylinder rotates to drive the auxiliary plate to rotate through the supporting frame, the auxiliary plate drives the winding drums in the auxiliary plate to rotate, the winding drums filled with cables are rotated to the rear portion, the empty winding drums are rotated to the front portion for work, and therefore the purpose of rapidly and circularly improving the working efficiency is achieved.

The utility model discloses an electromagnetic brake and drive assembly sealed with motor cooperation, and the electromagnetic brake includes the casing of one side open structure, and the casing open side is provided with the apron, and the casing is provided with armature and friction plate with apron, its characterized in that, the side of apron away from the casing is suitable for with motor cooperation, and the edge area of the side of apron away from the casing extends first flanging, and the end face of first flanging is suitable for with motor pressure, and the inner periphery of first flanging is provided with first sealing washer, wherein, the height of first sealing washer is greater than the height of first flanging. Thus, the first flanging and corresponding first sealing washer are arranged in the apron area of electromagnetic brake and motor cooperation, to seal the gap existing between the apron and motor end face. In this way, the output shaft of motor through to the first center hole of electromagnetic brake area is sealed in, can effectively prevent liquid or dust etc. from first center hole, keeps good sealing effect.

An electromagnetic brake control circuit is applied to an electromagnetic brake and a motor. The electromagnetic brake comprises an electromagnet; the electromagnetic brake control circuit comprises a microcontroller, a first transistor switch and a first diode. The microcontroller is configured to transmit a pulse width modulation signal to the first transistor switch to turn on or turn off the first transistor switch. When the electromagnetic brake control circuit is in a follow current stage of a driving mode, the first transistor switch is configured to be cut off by the pulse width modulation signal transmitted by the microcontroller, so that a coil driving current sequentially flows through the electromagnet and the first diode and then returns to the electromagnet; the electromagnetic brake control circuit is configured to drive the electromagnetic brake so that the electromagnetic brake stops braking the motor.

The present invention relates to the technical field of electric push rods. Disclosed is a novel intelligent electric push rod, specifically comprising an alternating-current permanent magnet motor and a push rod driven thereby. The alternating-current permanent magnet motor is provided with Hall sensors for detecting the position of a rotor of the alternating-current permanent magnet motor; and the electric push rod comprises at least one of an electromagnetic brake control unit, a wireless communication or wired communication unit, a power-off compensation braking unit, and a push rod stroke position detection unit. The electromagnetic brake control unit in the present invention achieves, in an electromagnetic brake manner, holding and braking of the push rod when current flows through windings of the alternating-current permanent magnet motor, thereby solving the problem of a self-locking failure caused by the reduction of a friction coefficient of a screw pair; additionally, the push rod stroke position detection unit achieves detection of the upper (lower) limit position of the push rod stroke, thereby avoiding the problems caused by a mechanical limit switch, and effectively improving the service life of a product; and the wireless communication or wired communication unit in the present solution can reduce the number of wire harnesses, thereby simplifying an assembly and wiring mode and a maintenance process.

The utility model provides a kind of electromagnetic brake, the electromagnetic brake includes the shell, clutch plate, friction disc and tail plate in turn stacked along preset path, the preset path is parallel to the axial direction of the shell, the shell is equipped with the elastic member and excitation coil acting on the clutch plate;Multiple first slots extending along its radial direction are opened on the clutch plate, the opening of the first slot extends to the outer ring of the clutch plate, and penetrates the clutch plate along the axial direction of the clutch plate, so that the clutch plate is composed of multiple action pieces evenly distributed around its axis;The elastic member includes multiple brake springs, multiple brake springs are one-to-one corresponding with the action piece Setting, and for abutting on the action piece. The electromagnetic brake provided by the utility model is more uniform to the friction effect of friction disc, reduces the local wear of friction disc;Metal powder accumulation in friction area can be reduced, so as to improve the service life of friction disc.

The invention belongs to the technical field of data processing and self-adaptive control, and provides an elevator priority scheduling control method and system based on operation data, and the method specifically comprises the steps: firstly, arranging a thermal imager and a voltage sensor in an elevator operation scene, recording a temperature curve through the thermal imager, recording an excitation current curve in real time through the voltage sensor, and obtaining a temperature curve; then the impact loss risk of the current operation state is judged through the temperature curve and the excitation current curve, and finally whether elevator dispatching strategy priority change is conducted or not is judged according to the impact loss risk. The magnetic fatigue induction degree of an impact event caused by the fact that an electromagnetic brake cannot accurately judge the actual elevator stopping time under the condition of executing a variable-speed scheduling mode of passenger load self-adaptive speed adjustment is effectively quantified; the irreversible magnetic hysteresis loss occurrence risk is effectively reduced; therefore, the service life of the electromagnetic brake in the elevator is prolonged, the problem of energy consumption caused by gradual accumulation of elevator operation power consumption is prevented, and the safety of passengers during elevator working is guaranteed.

An electromagnetic brake with a housing body and an armature disk, wherein the armature disk is guided axially via a groove-lug connection in the housing body, and wherein at least one guide groove and at least one associated guide lug are provided, wherein the respective guide groove is preferably arranged in the housing body.

The invention discloses an adjustable equally-divided brake clearance electromagnetic brake motor, which comprises a rotor assembly and a brake assembly, and is characterized in that the rotor assembly is provided with a motor shaft rotatably mounted in a motor shell in a limiting manner; the brake assembly comprises a cover plate, a friction assembly, an armature, a brake coil, a magnet yoke, a reset spring and a brake spring, a reset spring is embedded between the friction assembly and the motor shaft, and the friction assembly can move towards the side close to the armature through resilience force of the reset spring. The magnet yoke and the cover plate are installed at a fixed distance, the armature is arranged between the magnet yoke and the friction assembly in an axially movable mode, the brake coil is arranged in an annular groove of the magnet yoke and located between the magnet yoke and the armature, and the armature and the friction assembly are close to or away from the magnet yoke by switching on and off the brake coil. And the friction assembly is limited through a first limiting part and a second limiting part at the tail part of the motor shaft, so that the friction assembly is located at a proper position. The problem of friction ring plate burning in the prior art can be effectively solved, and the replacement efficiency is improved.

The utility model relates to the technical field of brakes, and provides a permanent magnet drum type electromagnetic brake which comprises a machine shell, a stator, a reset element and a rotor and further comprises a permanent magnet magnetized in the radial direction, the rotor is arranged in the machine shell in a penetrating mode, the permanent magnet is fixedly arranged on the rotor in a sleeved mode, the stator is arranged on the outer side of the permanent magnet, and the reset element is connected between the stator and the machine shell. The stator is attracted by the permanent magnet to generate pressure during power loss, so that braking is formed; the magnetic force generated when the stator is electrified repels the magnetic force of the permanent magnet, the stator is pulled open by the reset element, and braking is relieved. Compared with a traditional drum-type electromagnetic brake, a mechanical force transmission structure is not needed, the structure is simplified, braking and braking releasing are achieved only through the action of a magnetic field, and the response speed is increased.