Permanent magnet brake structure

Abstract

The utility model discloses a permanent magnet brake structure, and relates to the technical field of brakes. The permanent magnet is located between the coil and the armature, the permanent magnet is axially magnetized and can be integrally formed and conveniently assembled, different torque requirements can be met by matching different sizes of inner and outer magnetic pole faces, meanwhile, due to the fact that a magnetic circuit is short, magnetic leakage is small, and larger braking torque can be generated under the same size. And the requirement of normal work at the low temperature of minus 40 DEG C can be met.

Description

Technical Field

[0001] This utility model relates to the field of permanent magnet brake technology, and in particular to a permanent magnet brake structure. Background Technology

[0002] There are generally three types of electric braking: regenerative braking, dynamic braking and electromagnetic braking. Among them, electromagnetic braking is gradually adopting permanent magnet brakes, which is in line with the development trend of lighter and smaller motors and is currently the ideal automation actuator.

[0003] Currently, there are two main types of permanent magnet brake structures on the market, both of which have certain defects.

[0004] The first type, such as the Chinese utility model patent with authorization announcement number CN220935009U, involves a permanent magnet located at the bottom of the coil (on the side furthest from the armature). The permanent magnet is ring-shaped and axially magnetized. This structure results in a longer magnetic circuit and greater magnetic leakage, leading to a smaller braking torque for brakes of the same size. This, in turn, results in a narrower operating temperature range for the brake, especially below -20°C, where the brake will malfunction or even fail completely.

[0005] The second type, such as the Chinese utility model patent with authorization announcement number CN220227607U, involves a permanent magnet located between the coil and the armature. The permanent magnet is sleeve-shaped or cup-shaped, installed inside the outer magnetic pole, and is radially magnetized. While this structure shortens the magnetic circuit and reduces magnetic leakage compared to the first type, the fan-shaped distribution of the permanent magnets and their thinner wall thickness, typically arranged in multiple circumferential fan shapes, makes the assembly and magnetization process more complex. Furthermore, the proximity of the permanent magnet to the outer magnetic pole limits its versatility.

[0006] Given the shortcomings of existing technologies, there is an urgent need for a new type of permanent magnet brake structure. Utility Model Content

[0007] The main technical problem solved by this utility model is to provide a permanent magnet brake structure, which aims to overcome the shortcomings of existing permanent magnet brake structures and provide a new type of permanent magnet brake with better performance and wider application range.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] A permanent magnet brake structure includes a rotor section and a stator section arranged coaxially, with an air gap provided in the axial direction between the rotor section and the stator section, and the rotor section being rotatable relative to the stator section;

[0010] The stator includes a magnetic shell, and an annular groove is provided on the side of the magnetic shell facing the rotor. A coil, a lower flange, a permanent magnet and an upper flange are sequentially positioned from the bottom of the annular groove upwards. The lower flange is connected to the adjacent surface of the magnetic shell, and a magnetic blocking gap is provided between the upper flange and the adjacent surface of the magnetic shell. The permanent magnet is axially magnetized.

[0011] The rotor section includes a rotary flange, and an armature is connected to the side of the rotary flange facing the stator section via an elastic element. The armature is able to move up and down within the range of the air gap, and the elastic element has an elastic pulling force that moves the armature away from the stator section.

[0012] When the coil is not energized, a magnetic circuit is formed between the permanent magnet, the upper flange, the lower flange, the air gap, the armature, and the magnetic shell.

[0013] Furthermore, the permanent magnet is a monolithic structure in the shape of a ring, or the permanent magnet comprises a plurality of sector-shaped bodies arranged in a ring.

[0014] Furthermore, an inner magnetic pole surface is provided on the side of the upper flange adjacent to the armature, and an outer magnetic pole surface is provided on the side of the magnetic shell adjacent to the armature. The inner magnetic pole surface is flush with the outer magnetic pole surface or the inner magnetic pole surface is lower than the outer magnetic pole surface.

[0015] Furthermore, both the inner magnetic pole surface and the outer magnetic pole surface are annular surfaces.

[0016] Furthermore, the elastic element is a leaf spring, one end of which is fixedly connected to the slewing flange and the other end is fixedly connected to the armature.

[0017] Furthermore, the magnetically blocking gap is filled with air or a magnetically blocking material, which includes non-ferromagnetic materials such as copper.

[0018] Furthermore, the rotor can be mounted on the motor shaft and rotate or stop synchronously with the motor shaft.

[0019] The beneficial technical effects of this utility model are:

[0020] The permanent magnet of this invention is located between the coil and the armature, and the permanent magnet is axially magnetized, which facilitates assembly. Different torque requirements can be met by matching different inner and outer magnetic pole surface sizes. At the same time, due to the short magnetic circuit and less magnetic leakage, it can generate a larger braking torque under the same size, and can meet the requirements for normal operation at low temperatures down to -40℃. Attached Figure Description

[0021] Figure 1This is a schematic diagram of the overall structure of this utility model (sectional view, embodiment 1);

[0022] Figure 2 This is a schematic diagram of the overall structure of this utility model (sectional view, embodiment 2);

[0023] Figure 3 This is the closed magnetic circuit formed when the coil of this utility model is not energized (Example 1);

[0024] Figure 4 This is the closed magnetic circuit formed when the coil of this utility model is not energized (Example 2);

[0025] Figure 5 This is the closed magnetic circuit formed when the coil of this utility model is energized (Example 1);

[0026] Figure 6 This is the closed magnetic circuit formed when the coil of this utility model is energized (Example 2);

[0027] The parts in the attached diagram are labeled as follows:

[0028] 1. Rotor section; 11. Rotary flange; 12. Flexible element; 13. Armature;

[0029] 2. Stator section; 21. Magnetic shell; 211. Annular groove space; 212. Outer magnetic pole face; 22. Coil; 23. Lower flange; 24. Permanent magnet; 25. Upper flange; 251. Inner magnetic pole face; 26. Magnetic obstruction gap;

[0030] 3. Air gap. Detailed Implementation

[0031] In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0032] Example 1:

[0033] This specific embodiment discloses in detail a permanent magnet brake structure, such as... Figure 1 As shown:

[0034] It includes a rotor section 1 and a stator section 2 arranged coaxially, with an air gap 3 provided in the axial direction between the rotor section and the stator section, and the rotor section can rotate relative to the stator section.

[0035] The stator section includes a magnetic housing 21. An annular groove 211 is provided on the side of the magnetic housing facing the rotor section. From the bottom of the annular groove 211, a coil 22, a lower flange 23, a permanent magnet 24, and an upper flange 25 are sequentially positioned upwards. The lower flange is connected to the adjacent surface of the magnetic housing via a fit, which can be one of an interference fit, a transition fit, or a clearance fit, with an interference fit being preferred. If a clearance fit is used, the clearance is smaller. A magnetic blocking gap 26 is provided between the upper flange and the adjacent surface of the magnetic housing. The permanent magnet is axially magnetized, meaning it is magnetized along the axial direction of the permanent magnet. The permanent magnet is a single, ring-shaped structure, or it can be composed of multiple fan-shaped rings arranged in a ring shape; a single, ring-shaped structure is preferred.

[0036] The rotor section includes a rotary flange 11, and an armature 13 is connected to the side of the rotary flange facing the stator section via an elastic element 12. The armature can move up and down within the air gap range, and the elastic element has an elastic pulling force that moves the armature away from the stator section.

[0037] In this embodiment, the elastic element is a leaf spring. One end of the leaf spring is fixedly connected to the slewing flange, and the other end is fixedly connected to the armature. The fixed connection is achieved by riveting or threading.

[0038] An inner magnetic pole surface 251 is provided on the side adjacent to the upper flange and the armature, and an outer magnetic pole surface 212 is provided on the side adjacent to the magnetic shell and the armature. The inner magnetic pole surface and the outer magnetic pole surface are flush or the inner magnetic pole surface is lower than the outer magnetic pole surface, and both the inner magnetic pole surface and the outer magnetic pole surface are annular surfaces.

[0039] When the coil is not energized, a magnetic circuit is formed between the permanent magnet, the upper flange, the lower flange, the air gap, the armature, and the magnetic shell.

[0040] When this utility model is used, the rotary flange of the rotor is installed on the motor shaft, so the flange can rotate or stop with the motor shaft. The magnetic shell of the stator is generally fixed to the motor housing, so the stator will not rotate with the motor shaft.

[0041] In Embodiment 1, the inner ring end face of the magnetic shell is located below the upper flange, the upper flange through screws are fixedly connected to the top of the magnetic shell, and the magnetic blocking gap is located on the lower side of the upper flange.

[0042] Example 2:

[0043] like Figure 2 As shown: The functional structure is the same as that of Embodiment 1. The main difference is that the specific mating structure between the magnetic shell and the upper flange is different, resulting in a different setting direction of the magnetic blocking gap. The technical effects achieved by Embodiment 1 and Embodiment 2 are almost the same.

[0044] In Embodiment 2, the inner ring end face of the magnetic shell is higher than the top surface of the upper flange, and the magnetic blocking gap is located on the inner side of the upper flange.

[0045] The working principle is as follows:

[0046] like Figure 3 and Figure 4 As shown: When the coil is not energized, the armature is magnetized by the permanent magnet and simultaneously attracted by the magnetic forces of the inner and outer magnetic pole surfaces, causing the armature to come into contact with the outer magnetic pole surface, or with both the outer and inner magnetic pole surfaces simultaneously. At this time, the air gap is essentially zero, and the magnetic field lines generated by the permanent magnet mainly follow... Figure 3 and Figure 4 The path shown forms a closed loop, or it can be along the opposite direction of the arrow. The armature exerts a positive pressure on the outer magnetic pole surface, or simultaneously on both the inner and outer magnetic pole surfaces. When the armature rotates around the axis, or exhibits a tendency to rotate around the axis, it is subjected to magnetic friction from the outer magnetic pole surface, or simultaneously from both the outer and inner magnetic pole surfaces. This generates a braking torque on the armature, achieving a braking effect on the motor shaft. At this time, the magnetic gap can block or impede the passage of magnetic lines of force.

[0047] like Figure 5 and Figure 6 As shown: When the coil is energized, the magnetization direction of the permanent magnet is along the coil axis. Specifically, when the coil is energized, the magnetic field direction within the inner diameter of the coil must be opposite to the magnetization direction of the permanent magnet. At the instant the coil is energized, the magnetic field lines generated by the coil oppose the magnetic field lines of the permanent magnet within the armature, causing the magnetic field lines of both the permanent magnet and the coil to change direction. Figure 5 and Figure 6 The path shown has the magnetic field lines of the permanent magnet on the outer side and the magnetic field lines of the coil on the inner side. It is worth noting that the direction of the magnetic field lines of the permanent magnet and the coil in each part of the magnetic circuit can be the same as the direction shown by the arrow in the figure (when the magnetization direction of the permanent magnet is upward along the armature rotation axis), or opposite to the direction shown by the arrow in the figure (when the magnetization direction of the permanent magnet is downward along the armature rotation axis).

[0048] At this point, the magnetic attraction force on the armature is greatly reduced, becoming less than the elastic force of the leaf spring, causing the armature to move upward until it is in contact with the slewing flange. The armature then separates from the friction surface. At this time, the air gap is not zero, and the armature can rotate freely with the motor shaft. The brake does not have a braking function.

[0049] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0050] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0051] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A permanent magnet brake structure, comprising a rotor portion (1) and a stator portion (2) coaxially arranged, wherein an air gap (3) is provided in the axial direction between the rotor portion and the stator portion, and the rotor portion is rotatable relative to the stator portion, characterized in that: The stator includes a magnetic shell (21), and an annular groove space (211) is provided on the side of the magnetic shell facing the rotor. A coil (22), a lower flange (23), a permanent magnet (24) and an upper flange (25) are sequentially positioned from the bottom of the annular groove space upwards. The lower flange is connected to the adjacent surface of the magnetic shell, and a magnetic blocking gap (26) is provided between the upper flange and the adjacent surface of the magnetic shell. The permanent magnet is axially magnetized. The rotor section includes a rotary flange (11), and an armature (13) is connected to the side of the rotary flange facing the stator section via an elastic element (12). The armature is able to move up and down within the range of the air gap, and the elastic element has an elastic pulling force that moves the armature away from the stator section. When the coil is not energized, a magnetic circuit is formed between the permanent magnet, the upper flange, the lower flange, the air gap, the armature, and the magnetic shell.

2. The permanent magnet brake structure according to claim 1, characterized in that: The permanent magnet is a single, ring-shaped structure, or the permanent magnet comprises multiple sector-shaped bodies arranged in a ring shape.

3. The permanent magnet brake structure according to claim 1, characterized in that: An inner magnetic pole surface (251) is provided on the side of the upper flange adjacent to the armature, and an outer magnetic pole surface (212) is provided on the side of the magnetic shell adjacent to the armature. The inner magnetic pole surface is flush with the outer magnetic pole surface or the inner magnetic pole surface is lower than the outer magnetic pole surface.

4. The permanent magnet brake structure according to claim 3, characterized in that: Both the inner magnetic pole surface and the outer magnetic pole surface are annular surfaces.

5. The permanent magnet brake structure according to claim 1, characterized in that: The elastic element is a leaf spring, one end of which is fixedly connected to the slewing flange and the other end is fixedly connected to the armature.

6. The permanent magnet brake structure according to claim 1, characterized in that: The magnetic blocking gap is filled with air or magnetic blocking material.

7. The permanent magnet brake structure according to claim 1, characterized in that: The rotor can be mounted on the motor shaft and rotate or stop synchronously with the motor shaft.

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