Permanent magnet brake structure

Abstract

The invention 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] The invention relates to the technical field of permanent magnet brakes, and in particular to a permanent magnet brake structure. Background Art

[0002] There are three common types of electric braking: regenerative braking, dynamic braking and electromagnetic braking. Among them, electromagnetic braking gradually adopts permanent magnet brakes, which conforms to the development trend of lighter and smaller motors and is currently an ideal automation actuator.

[0003] Currently, there are two main 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, has a permanent magnet located at the bottom of the coil (the side away from the armature), is annular, and is axially magnetized. This structure results in a longer magnetic circuit and more magnetic leakage, which results in a smaller braking torque for the same size of brake. This in turn results in a narrower operating temperature range for the brake, especially when the temperature is below -20°C, the brake will not work properly or even fail completely.

[0005] The second type, such as the Chinese utility model patent with authorization announcement number CN220227607U, has 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. Although this structure shortens the magnetic circuit and reduces magnetic leakage compared to the first type, the permanent magnet is fan-shaped and has a thin wall. It is generally made into a fan-shaped, circumferential distribution, which makes its assembly and magnetization process more complicated. In addition, since the permanent magnet is close to the outer magnetic pole, the versatility of the permanent magnet is also limited.

[0006] In view of the shortcomings of the existing technology, a new type of permanent magnet brake structure is urgently needed. Summary of the invention

[0007] The main technical problem solved by the present invention is to provide a permanent magnet brake structure, aiming to overcome the shortcomings of the existing permanent magnet brake structure and provide a new type of permanent magnet brake with better performance and wider application range.

[0008] In order to solve the above technical problems, a technical solution adopted by the present invention is:

[0009] A permanent magnet brake structure comprises a coaxially arranged rotor part and a stator part, an air gap is arranged between the rotor part and the stator part in the axial direction, and the rotor part can rotate relative to the stator part;

[0010] The stator part comprises a magnetic shell, a side of the magnetic shell facing the rotor part is provided with an annular groove-shaped space, a coil, a lower flange, a permanent magnet and an upper flange are positioned and arranged in sequence from the bottom of the annular groove-shaped space upward, the lower flange is matched and connected with the adjacent surface of the magnetic shell, a magnetic blocking gap is provided between the upper flange and the adjacent surface of the magnetic shell, and the permanent magnet is axially magnetized;

[0011] The rotor part comprises a rotary flange, a side of the rotary flange facing the stator part is connected to an armature through an elastic member, the armature can move up and down within the range of the air gap, and the elastic member has an elastic pulling force to make the armature move away from the stator part;

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

[0013] Furthermore, the permanent magnet is an integral structure in the shape of a circular ring, or the permanent magnet includes a plurality of sectors arranged in the shape of a circular ring.

[0014] Furthermore, an inner magnetic pole surface is provided on one side of the upper flange adjacent to the armature, an outer magnetic pole surface is provided on one side of the magnetic shell adjacent to the armature, and 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, the inner magnetic pole surface and the outer magnetic pole surface are both annular surfaces.

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

[0017] Furthermore, the magnetic-resistance gap is filled with air or magnetic-resistance material, and the magnetic-resistance material includes non-ferromagnetic materials such as copper.

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

[0019] The beneficial technical effects of the present invention are:

[0020] The permanent magnet of the present invention is located between the coil and the armature, and the permanent magnet is axially magnetized, which is easy to assemble. Different torque requirements can be met by matching different inner and outer pole surface sizes. At the same time, due to the shorter magnetic circuit and less leakage magnetism, a larger braking torque can be generated under the same size, and the requirements for normal operation can be met at low temperatures as low as -40°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention (sectional view, embodiment 1);

[0022] Figure 2 It is a schematic diagram of the overall structure of the present invention (sectional view, embodiment 2);

[0023] Figure 3 It is a closed magnetic circuit formed when the coil of the present invention is not energized (Example 1);

[0024] Figure 4 It is a closed magnetic circuit formed when the coil of the present invention is not energized (Example 2);

[0025] Figure 5 It is a closed magnetic circuit formed when the coil of the present invention is energized (Example 1);

[0026] Figure 6 It is a closed magnetic circuit formed when the coil of the present invention is energized (Example 2);

[0027] The parts in the accompanying drawings are marked as follows:

[0028] 1. rotor part; 11. rotary flange; 12. elastic member; 13. armature;

[0029] 2. stator part; 21. magnetic shell; 211. annular groove-shaped space; 212. outer magnetic pole surface; 22. coil; 23. lower flange; 24. permanent magnet; 25. upper flange; 251. inner magnetic pole surface; 26. magnetic blocking gap;

[0030] 3. Air gap. DETAILED DESCRIPTION

[0031] In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples. The following examples are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0032] Embodiment 1:

[0033] This specific embodiment discloses a permanent magnetic brake structure in detail. Figure 1 As shown:

[0034] The invention comprises a coaxially arranged rotor part 1 and a stator part 2, an air gap 3 is arranged between the rotor part and the stator part in the axial direction, and the rotor part can rotate relative to the stator part.

[0035] The stator part includes a magnetic shell 21, and an annular groove-shaped space 211 is provided on the side of the magnetic shell facing the rotor part. A coil 22, a lower flange 23, a permanent magnet 24 and an upper flange 25 are positioned in sequence from the bottom of the annular groove-shaped space upward; the lower flange is fitted and connected with the adjacent surface of the magnetic shell, and the fitting connection here is one of interference fit / transition fit / clearance fit, among which interference fit is preferred, and if it is a clearance fit, the gap is smaller. A magnetic blocking gap 26 is provided between the upper flange and the adjacent surface of the magnetic shell, and the permanent magnet is axially magnetized, and the axial magnetization here is the axial magnetization method of the permanent magnet. The permanent magnet is an integral structure in the shape of a circular ring, or is arranged in a circular ring by a plurality of fan-shaped bodies, and is preferably an integral structure;

[0036] The rotor part includes a rotating flange 11, and the side of the rotating flange facing the stator part is connected to an armature 13 through an elastic member 12. The armature can move up and down within the range of the air gap, and the elastic member has an elastic pulling force to keep the armature away from the stator part.

[0037] In this embodiment, the elastic member is a leaf spring, one end of which is fixedly connected to the rotary flange, and the other end of which is fixedly connected to the armature. The fixed connection here is through riveting or threaded connection.

[0038] An inner magnetic pole surface 251 is provided on one side of the upper flange adjacent to the armature, and an outer magnetic pole surface 212 is provided on one 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, 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 conductive circuit is formed among the permanent magnet, the upper flange, the lower flange, the air gap, the armature and the magnetic shell.

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

[0041] In the first embodiment, the inner ring end surface of the magnetic shell is located below the upper flange, the upper flange is fixedly connected to the top of the magnetic shell by screws, and the magnetic blocking gap is located at the lower side of the upper flange.

[0042] Embodiment 2:

[0043] like Figure 2 As shown: the functional structure is the same as that of the first embodiment, the main difference is that the specific matching structure between the magnetic shell and the upper flange is different, so the setting direction of the magnetic blocking gap is different. The technical effects achieved by the first embodiment and the second embodiment are almost the same.

[0044] In the second embodiment, the inner ring end surface of the magnetic shell is higher than the top surface of the upper flange, and the magnetic blocking gap is located at the inner side of the upper flange.

[0045] Here’s how it works:

[0046] like Figure 3 and Figure 4 As shown in the figure: when the coil is not energized, the armature is magnetized by the permanent magnet and attracted by the magnetic force of the inner and outer magnetic pole surfaces, so that the armature fits the outer magnetic pole surface, or the armature fits the outer and inner magnetic pole surfaces at the same time. At this time, the air gap is equivalent to 0, and the magnetic lines of force generated by the permanent magnet are mainly along Figure 3 and Figure 4 The path shown in the figure forms a closed loop, or it can be in the opposite direction of the arrow shown. The armature generates positive pressure on the outer magnetic pole surface, or the armature generates positive pressure on both the inner magnetic pole surface and the outer magnetic pole surface. When the armature rotates around the axis, or shows a tendency to rotate around the axis, the armature will be affected by the magnetic friction force of the outer magnetic pole surface, or by the magnetic friction force of both the outer magnetic pole surface and the inner magnetic pole surface, thereby generating a braking torque on the armature to achieve a braking effect on the motor shaft. At this time, the magnetic blocking gap can block or hinder the passage of magnetic lines of force.

[0047] like Figure 5 and Figure 6 As shown in the figure: When the coil is energized, the magnetization direction of the permanent magnet is along the axial direction of the coil. 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. When the coil is energized, the magnetic lines of force generated by the coil oppose the magnetic lines of force of the permanent magnet in the armature, and the magnetic lines of force generated by the coil oppose the magnetic lines of force of the permanent magnet in the armature, resulting in the direction of the magnetic lines of force of the permanent magnet and the coil being transformed into Figure 5 and Figure 6 The path shown in the figure, where the outer side is the magnetic force lines of the permanent magnet, and the inner side is the magnetic force lines of the coil. It is worth noting that the direction of the magnetic force lines of the permanent magnets and coils in each part of the magnetic path can be consistent with 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 time, the magnetic attraction force on the armature is greatly reduced and is smaller than the elastic force of the leaf spring, causing the armature to move upward to fit the rotating flange, and the armature is separated from the friction surface. At this time, the air gap is not 0, the armature can rotate freely with the motor shaft, and the brake has no braking function.

[0049] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0050] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "set" should be understood in a broad sense, for example, they can be fixedly connected or set, or detachably connected or set, or integrally connected or set. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A permanent magnet brake structure, comprising a coaxially arranged rotor part (1) and a stator part (2), an air gap (3) being arranged between the rotor part and the stator part in the axial direction, the rotor part being rotatable relative to the stator part, characterized in that: The stator part comprises a magnetic shell (21), a side of the magnetic shell facing the rotor part is provided with an annular groove-shaped space (211), a coil (22), a lower flange (23), a permanent magnet (24) and an upper flange (25) are positioned and arranged in sequence from the bottom of the annular groove-shaped space upward, the lower flange is matched and connected with the adjacent surface of the magnetic shell, a magnetic blocking gap (26) is provided between the upper flange and the adjacent surface of the magnetic shell, and the permanent magnet is axially magnetized; The rotor part comprises a rotating flange (11), a side of the rotating flange facing the stator part is connected to an armature (13) via an elastic member (12), the armature can move up and down within the range of the air gap, and the elastic member has an elastic pulling force that causes the armature to move away from the stator part; When the coil is not energized, a magnetic conductive circuit is formed among the permanent magnet, the upper flange, the lower flange, the air gap, the armature and the magnetic shell.

2. A permanent magnet brake structure according to claim 1, characterized in that: The permanent magnet is an integral structure in a circular ring shape, or the permanent magnet includes a plurality of sector-shaped bodies arranged in a circular ring shape.

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

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

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

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

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

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