Permanent magnet brake that uses the principle of repulsion between like magnetic poles for braking and release.

Abstract

This invention discloses a permanent magnet brake based on the principle of like pole repulsion for braking and release. It includes a rotor flange and a magnetic housing arranged opposite each other, with an axially movable armature positioned between the magnetic housing and the rotor flange. A permanent magnet is mounted on the end face of the armature facing the magnetic housing, and an annular receiving cavity is formed on the end face of the magnetic housing facing the armature. A set of electromagnets is circumferentially evenly distributed within the receiving cavity. When the electromagnets are energized, their generated magnetic poles are arranged in a like-pole configuration with the permanent magnet poles, and the magnetic repulsion between the electromagnets and the permanent magnets is greater than the magnetic attraction between the permanent magnets and the magnetic housing. This invention relies on the principle of like pole repulsion, resulting in a fast braking and release response. It directly completes the braking and release actions using magnetic force, eliminating the need for traditional spring components, resulting in fewer parts and a more compact structure.

Description

Technical Field

[0001] This invention relates to the field of braking technology, and more particularly to a permanent magnet brake that releases the brake based on the principle of repulsion between like magnetic poles. Background Technology

[0002] Permanent magnet brakes are a new type of torque control device. They achieve torque coupling between the output shaft and the machine body through magnetic pair connection, and can decelerate or stop moving components. They are widely used in metallurgy, construction, chemical industry, food, machine tools, stage equipment, elevators, ships, packaging machinery and other fields.

[0003] Currently, the mainstream permanent magnet brakes on the market can be referenced by Chinese patent CN220828454U, whose structure is as follows: Figure 6 and Figure 7 As shown, it includes a rotor assembly and a stator assembly. The rotor assembly includes a hub 101, a leaf spring 102, and an armature 103. The motor shaft is inserted into the hub 101. The upper surface of the armature 103 is fixedly connected to the lower surface of the leaf spring 102, and the upper surface of the leaf spring 102 is fixedly connected to the lower surface of the hub 101. The stator assembly includes a magnetic housing 104 fixedly disposed relative to each other, in which a coil 105 and a permanent magnet 106 are installed. The permanent magnet 106 is disposed around the periphery of the central electric drive. In the prior art, the magnetization direction of the permanent magnet is generally radial. When the electromagnetic brake is in braking condition, the coil is de-energized, such as... Figure 6 As shown, the armature 103 moves downward under the magnetic force of the permanent magnet 106, pressing against the outer edge of the magnetic shell 104, thus braking the hub 101 and the motor shaft. When the electromagnetic brake is in the brake release condition, as... Figure 7 As shown, when the coil is energized, the electromagnetic force generated cancels the magnetic force of the permanent magnet. The armature 103 is reset under the elastic force of the plate spring 102 and moves upward to be close to the outer edge of the hub 101 and away from the outer edge of the magnetic shell 104.

[0004] Existing technology has significant drawbacks: during brake release, the electromagnetic force must first counteract the strong magnetic force of a permanent magnet before the plate spring can slowly pull the armature away to reset. This brake release response time is too long, making it unsuitable for applications requiring high-frequency, rapid start-stop, such as robot control systems. Furthermore, residual magnetism in the permanent magnet is prone to occur during operation, leading to incomplete brake release and dragging noises. In addition, traditional weak magnetic brakes suffer from slow braking action due to the weak magnetic field lines being conducted through the magnetic shell; when the coil is de-energized, the shell demagnetizes slowly. This poses a safety hazard. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a permanent magnet brake that uses the principle of repulsion between like magnetic poles for braking and release, thus solving the problems of slow response, residual magnetic drag, complex structure, and braking lag in traditional brakes.

[0006] The objective of this invention is achieved through the following technical solution: A permanent magnet brake based on the principle of repulsion between like magnetic poles for braking release includes a rotor flange and a magnetic housing arranged opposite each other. The rotor flange is fixed to the end face of a motor shaft and rotates coaxially with it. The magnetic housing is fixed to a fixed flange. An armature that can move axially is provided between the magnetic housing and the rotor flange. An annular groove is provided on the end face of the armature facing the magnetic housing. A permanent magnet is fixed in the annular groove. An annular receiving cavity is opened on the end side of the magnetic housing facing the armature. An electromagnet that can be magnetized is fixedly installed in the receiving cavity. The electromagnet includes at least a coil that can generate electromagnetic force when energized. When the coil is energized, the electromagnetic poles generated by the electromagnet and the magnetic poles of the permanent magnet are in a state of like magnetic poles facing each other, and the magnetic repulsion force formed between the electromagnet and the permanent magnet is greater than the magnetic attraction force formed between the permanent magnet and the magnetic housing.

[0007] Preferably, the electromagnet is composed of a group of electromagnet units connected in series. Each electromagnet unit includes a core column and a coil unit wound around the outside of the core column. The coil units are connected in series and evenly arranged in the circumferential direction inside the receiving cavity.

[0008] Preferably, the annular groove is a spaced, discontinuous groove, and the shape of the permanent magnet matches the annular groove.

[0009] Preferably, the permanent magnet is axially magnetized.

[0010] Preferably, the permanent magnet is fixed to the annular groove of the armature by high-temperature resistant epoxy resin adhesive or by riveting process.

[0011] Preferably, the permanent magnet has a fan-shaped segmented splicing structure, with non-magnetic insulating strips embedded between each segment of the permanent magnet.

[0012] Preferably, a limiting component is provided between the armature and the rotor flange to restrict the circumferential rotation of the armature. The limiting component includes at least one guide pin fixedly disposed on the end face of the rotor flange facing the armature, and the armature is provided with a guide hole adapted to the guide pin.

[0013] Preferably, a self-lubricating bearing is provided inside the guide hole.

[0014] Preferably, the motor shaft is a hollow shaft body, in which an encoder for controlling the motor and a connecting cable are installed in the hollow inner hole.

[0015] Preferably, the contact area where the armature, rotor flange, and magnetic shell meet is coated with a wear-resistant coating.

[0016] The beneficial effects of this invention are mainly reflected in: 1. Utilizing the principle of repulsion between the like poles of an electromagnet and a permanent magnet, a repulsive force can be directly generated between the electromagnet and the permanent magnet after the coil is energized. Only a smaller current is needed to generate electromagnetic force and permanent magnet force to actively and quickly push the armature away, thereby greatly shortening the braking release time. It is especially suitable for high-frequency and high-response applications, such as industrial robot servo motors or actuators that require precise positioning and rapid start and stop. 2. Since the braking release force comes from the active repulsion after the coil is energized, its force is much greater than the possible weak residual magnetic attraction force. Therefore, each braking release is absolutely crisp and thorough, ensuring the rotational freedom and precision of the hub and motor shaft. 3. Since the braking release force comes from the active repulsion after the coil is energized, the required electromagnetic force will be much smaller than that required by existing technology. Therefore, a set of smaller electromagnets connected in series can be used to form the electromagnetic force. The coils of this set of electromagnets use thin copper wire, have low power, and generate less heat. 4. Compared with existing technologies, it eliminates the need for leaf springs, resulting in fewer parts and a more compact structure. At the same time, the release action, which utilizes the repulsive force generated by the repulsion between the like poles of an electromagnet and a permanent magnet, is gentler and more controllable than the tension of a leaf spring, reducing impact and noise. Attached Figure Description

[0017] The technical solution of the present invention will be further described below with reference to the accompanying drawings: Figure 1 : A schematic diagram of a preferred embodiment of the present invention in a braking state; Figure 2 : A schematic diagram of a preferred embodiment of the present invention in the energized release state; Figure 3 : An exploded view of a preferred embodiment of the present invention, omitting the motor shaft and the fixing flange; Figure 4 : A perspective view of the magnetic shell and electromagnet in a preferred embodiment of the present invention; Figure 5 : A perspective view of the armature and permanent magnet in a preferred embodiment of the present invention; Figure 6 : A schematic diagram of the magnetic circuit of a permanent magnet brake in the braking state in the prior art; Figure 7 : Schematic diagram of the magnetic circuit of a permanent magnet brake in the energized release state. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments are not limited to the present invention, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the scope of protection of the present invention.

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] like Figures 1 to 5 As shown, this invention discloses a permanent magnet brake, including a rotor flange 1 and a magnetic housing 2 arranged opposite to each other. The rotor flange 1 is fixed to a motor shaft 8 and rotates coaxially with it. The fixing method can be conventional fixing methods such as screws or riveting. In this embodiment of the invention, the motor shaft 8 is a hollow shaft, and its inner hole 4 is provided with an encoder 7 for controlling the motor and a cable. As is well known to those skilled in the art, the encoder 7 controls the rotation of the motor rotor, which can drive the motor shaft 8 and the rotor flange 1 to rotate. At the same time, the encoder 7 can monitor the speed, position and other information of the drive motor in real time, providing accurate data support for the control of the brake. The magnetic housing 2 can be fixed to the fixed flange 9 with screws, so the magnetic housing 2 is relatively fixed and cannot rotate.

[0023] In this invention, an axially movable armature 3 is provided between the magnetic housing 2 and the rotor flange 1. An annular groove 31 is provided on the end face of the armature 3 facing the magnetic housing 2, and a permanent magnet 6 is fixed within the annular groove 31, the permanent magnet 6 being axially magnetized. Figure 5 As shown, in this preferred embodiment, the annular groove 31 is a spaced, discontinuous groove, and the shape of the permanent magnet 6 matches the annular groove 31. That is, the permanent magnet 6 has a fan-shaped segmented splicing structure, with non-magnetic insulating strips embedded between each segment of the permanent magnet, which can block circumferential magnetic bypass leakage.

[0024] The permanent magnet 6 is fixed to the annular groove 31 of the armature 3 by high-temperature epoxy resin adhesive or by riveting. Of course, the shape and number of the annular groove 31 are variable; for example, a single, complete arc-shaped annular groove can be used. Facing the rotor flange 1, the outer surface of the permanent magnet 6 is lower than the outer surface of the armature 3. That is, the permanent magnet is completely enclosed inside the armature, effectively preventing direct impact or wear during assembly and operation.

[0025] The magnetic shell 2 has an annular cavity 21 on its end facing the armature 3. An electromagnet 5, which can be magnetized by energization, is fixedly installed within the cavity 21. The electromagnet 5 includes at least a coil that generates electromagnetic force when energized. Preferably, combined with... Figure 3 and Figure 4 As shown, the electromagnet 5 is composed of a group of electromagnet units 50 connected in series. Each electromagnet unit 50 includes a core post 51 and a coil unit 52 wound around the outside of the core post. The coil units 52 are connected in series and are evenly arranged in the circumferential direction inside the receiving cavity 21.

[0026] A limiting component is provided between the armature 3 and the rotor flange 1 to restrict the circumferential rotation of the armature 3. The limiting component includes at least one guide pin 11 fixedly disposed on the end face of the rotor flange 1 facing the armature 3. A guide hole 32 adapted to the guide pin 11 is provided on the armature 3. Preferably, a self-lubricating bearing is provided within the guide hole 32. The cooperation between the guide pin 11 and the guide hole 32 forces the armature to move only in a straight axial direction, preventing circumferential rotation or radial offset during engagement or disengagement. This ensures that the friction surfaces of the armature and the magnetic housing 2 can be completely parallel and in contact, thereby ensuring uniform distribution of braking torque, consistent wear, and reducing vibration and noise caused by skewness, thus improving the reliability and consistency of braking action. Furthermore, a wear-resistant coating is applied to the contact area where the armature 3, rotor flange 1, and magnetic housing 2 form a surface contact.

[0027] The working process of this invention is briefly described below: When the electromagnet 5 is de-energized, the magnetic field generated by the permanent magnet 6 attracts the magnetic shell 2, driving the armature 3 to move along the guide pin 11 and engage with the magnetic shell 2. The friction between the armature 3 and the magnetic shell 2 causes the armature 3 to brake. At this time, due to the action of the guide pin 11, a circumferential rotation limit is generated between the armature 3 and the rotor flange 1, realizing the braking of the rotor flange 1 and the motor shaft 8.

[0028] When electromagnet 5 is energized, the electromagnetic poles generated by electromagnet 5 and the magnetic poles of permanent magnet 6 are in a state of opposite polarity, that is, the magnetic pole near the armature 3 and the magnetic pole of permanent magnet 6 are both polarities, for example, both being N poles. Based on the principle of repulsion between like magnetic poles, an axial repulsive force is generated between electromagnet 5 and permanent magnet 6. At the same time, the magnetic repulsive force formed between electromagnet 5 and permanent magnet 6 is greater than the magnetic attraction force formed between permanent magnet 6 and magnetic shell 2. In this way, the armature 3 can be actively and quickly pushed away, thereby significantly shortening the braking release time.

[0029] Because the coil generates a direct repulsive force between the electromagnet and the permanent magnet after being energized, the required electromagnetic force is much smaller than that required by existing technologies. Therefore, this invention can use a more miniaturized coil unit 52 to form the electromagnet 5. The coil of this electromagnet uses thin copper wire, has low power, and generates less heat. At the same time, since the braking release force comes from the active repulsion after the coil is energized, its strength is far greater than the possible weak residual magnetic attraction force. Therefore, each braking release is absolutely crisp and complete.

[0030] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0031] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A permanent magnet brake based on the principle of repulsion between like magnetic poles for braking and release, comprising a rotor flange (1) and a magnetic housing (2) arranged opposite to each other, wherein the rotor flange (1) is fixed to the end face of a motor shaft (8) and rotates coaxially with it, the magnetic housing (2) is fixed to a fixed flange (9), and an armature (3) that can move axially is provided between the magnetic housing (2) and the rotor flange (1), characterized in that: The armature (3) has an annular groove (31) on its end face facing the magnetic shell (2). A permanent magnet (6) is fixed in the annular groove (31). A circular receiving cavity (21) is opened on the end side of the magnetic shell (2) facing the armature (3). An electromagnet (5) that can be excited and magnetized is fixedly installed in the receiving cavity (21). The electromagnet (5) includes at least a coil that can generate electromagnetic force when energized. When the coil is energized, the electromagnetic poles generated by the electromagnet (5) and the magnetic poles of the permanent magnet (6) are in the same magnetic pole opposite state. The magnetic repulsion between the electromagnet (5) and the permanent magnet (6) is greater than the magnetic attraction between the permanent magnet (6) and the magnetic shell (2).

2. The permanent magnet brake based on the principle of repulsion between like magnetic poles for braking and release according to claim 1, characterized in that: The electromagnet (5) is composed of a group of electromagnet units (50) connected in series. Each electromagnet unit (50) includes a core column (51) and a coil unit (52) wound around the outside of the core column. Each coil unit (52) is connected in series and evenly arranged in the circumferential direction inside the receiving cavity (21).

3. The permanent magnet brake based on the principle of repulsion between like magnetic poles for braking and release according to claim 1, characterized in that: The annular groove (31) is a spaced, discontinuous groove, and the shape of the permanent magnet (6) matches the annular groove (31).

4. The permanent magnet brake based on the principle of repulsion between like magnetic poles for braking and release according to claim 3, characterized in that: The permanent magnet (6) is axially magnetized.

5. The permanent magnet brake based on the principle of repulsion between like magnetic poles for braking and release according to claim 4, characterized in that: The permanent magnet (6) is fixed in the annular groove (31) of the armature (3) by high-temperature epoxy resin adhesive or by riveting process.

6. The permanent magnet brake based on the principle of repulsion between like magnetic poles for braking and release according to claim 3, characterized in that: The permanent magnet (6) is a fan-shaped segmented splicing structure, with non-magnetic insulating strips embedded between each segment of the permanent magnet.

7. The permanent magnet brake based on the principle of repulsion between like magnetic poles for braking and release according to claim 1, characterized in that: A limiting component is provided between the armature (3) and the rotor flange (1) to restrict the circumferential rotation of the armature (3). The limiting component includes at least one guide pin (11) fixedly disposed on the end face of the rotor flange (1) facing the armature (3). A guide hole (32) adapted to the guide pin (11) is provided on the armature (3).

8. The permanent magnet brake based on the principle of repulsion between like magnetic poles for braking and release according to claim 7, characterized in that: A self-lubricating bearing is provided inside the guide hole (32).

9. The permanent magnet brake based on the principle of repulsion between like magnetic poles for braking and release according to claim 1, characterized in that: The motor shaft (8) is a hollow shaft, in which an encoder (7) for controlling the motor and a connecting cable are installed in the hollow inner hole (4).

10. The permanent magnet brake based on the principle of repulsion between like magnetic poles for braking and release according to claim 1, characterized in that: The contact area formed by the armature (3), rotor flange (1) and magnetic shell (2) is coated with a wear-resistant coating.

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