CN111416496A - A Moving Coil Electromagnetic Linear Actuator Based on Compound Halbach Array - Google Patents

Abstract

The invention discloses a moving coil electromagnetic linear actuator based on a compound Halbach array, comprising: an end cover, a coil bobbin, a magnetic yoke, an electromagnetic coil group, a main Halbach array layer, an auxiliary Halbach array layer, an air gap, a spacer Magnetic shaft and resonant spring; composite Halbach array, including main Halbach array layer and auxiliary Halbach array layer, the main array layer is composed of axially magnetized permanent magnets and radially magnetized permanent magnets which are alternately arranged in close contact with each other. The magnetized permanent magnets and the auxiliary array layers, which are alternately arranged in close contact with each other, are fixed on the magnetic isolation shaft as a magnetic source; the electromagnetic coil group is embedded in the coil skeleton, the actuator, and can Reciprocating linear motion is performed in the gap, the main Halbach array layer is located between the mover and the auxiliary Halbach array layer; the yoke and the magnetic source are set to be fixed and used as the stator, and the gap between the two is an air gap. The moving coil electromagnetic linear actuator of the present invention adopts a compound Halbach array, which improves the self-shielding capability of the magnetic circuit and the power density of the actuator, and has good control characteristics and stability.

Description

A Moving Coil Electromagnetic Linear Actuator Based on Compound Halbach Array

technical field

The invention relates to the technical field of motors, in particular to a moving coil electromagnetic linear actuator based on a compound Halbach array.

Background technique

As a driving element, the electromagnetic linear actuator can directly convert the input electrical energy into mechanical energy of linear motion, which is suitable for applications such as linear motion, large driving force and smooth feeding. The moving coil electromagnetic linear actuator has the advantages of high frequency response and high precision, so it has received extensive attention. In recent years, driven by new demands, new materials and new technologies, especially the wide application of permanent magnet materials such as sintered NdFeB, electromagnetic linear actuators have achieved greater development.

In the application of electromagnetic linear actuators, the contradiction between drive requirements and limited installation space provides a test for the compactness and reliability of the actuator. Obtaining the maximum output value with a smaller volume has become the current stage of electromagnetic linear actuators. The primary goal of the actuator is to provide greater volume power density to ensure the coordination and stability of the entire electric drive linear system, which can effectively improve the contrast between the size space and the output characteristics. Although the ordinary Halbach array can effectively enhance the magnetic flux density on one side of the permanent magnet and weaken the magnetic flux density on the other side, increasing the air gap magnetic density to a certain extent, there is still a large amount of magnetic flux leakage, and the power density of such electromagnetic actuators is still To be further improved. At the same time, the electromagnetic actuator based on the common Halbach array needs an extra yoke to fix the permanent magnet material, which increases the difficulty of assembling the actuator.

A moving coil electromagnetic linear actuator based on a compound Halbach array of the present invention adopts an auxiliary Halbach array layer to reduce the magnetic flux leakage of the main Halbach array layer, further enhances the air gap magnetic density, and improves the volume power of the electromagnetic linear actuator. The density can effectively improve the power transmission efficiency of the entire electromechanical system, and ensure the work coordination and wide application of the linear actuator.

SUMMARY OF THE INVENTION

The purpose of designing a moving coil electromagnetic linear actuator based on a composite Halbach array is to use a composite Halbach array to improve the self-shielding capability of the magnetic circuit, and the permanent magnets can be fixed on non-magnetic conductive materials without additional magnetic The yoke reduces the difficulty of assembly; at the same time, it can significantly improve the power density of the actuator and solve the contradiction between driving requirements and limited installation space. The actuator has higher power density and lower assembly difficulty, and has high research and practical value.

A moving coil electromagnetic linear actuator based on a composite Halbach array, characterized in that it comprises: an end cover (1), a coil bobbin (2), a magnetic yoke (3), an electromagnetic coil set (4), a main Halbach The array layer (5), the auxiliary Halbach array layer (6), the air gap (8), the magnetic isolation shaft (9) and the resonant spring (10), the main features include: a composite Halbach array, including the main Halbach array layer (5) and the auxiliary Halbach array layer (6), the main array layer is composed of axially magnetized permanent magnets (7.1) and radially magnetized permanent magnets (7.2) arranged in close contact with each other, and the axially magnetized permanent magnets (7.1) The auxiliary array layers, which are alternately arranged in close contact with each other, and the inter-magnetic magnetic permeable blocks (7.3) are fixed on the magnetic isolation shaft (9) as a magnetic source; the magnetic yoke (3) and the magnetic source are set to be fixed, and the gap between them is The air gap (8) is used as a stator; the electromagnetic coil group (4) is embedded on the coil bobbin (2), and can perform reciprocating linear motion in the air gap (8) to act as an actuator; the compound Halbach array is arranged on the electromagnetic The coil assembly (4) is unilateral, and the main Halbach array layer (5) close to the electromagnetic coil assembly (4).

The electromagnetic coil group (4) is composed of a forward winding coil and a reverse winding coil, and the winding directions of adjacent windings are opposite, wherein the number of forward windings is m, the number of reverse windings is n, m, n All are positive integers, m=n or m-n=±1.

The outer main Halbach array (5) is composed of p axially magnetized permanent magnets (7.1) and k radially magnetized permanent magnets (7.2); the inner layer auxiliary Halbach array (6) consists of p axial magnets (7.2). It is composed of a magnetized permanent magnet (7.4) and k intermagnetic permeable blocks (7.3); among them, p=k+1, and p and k are both positive integers.

The number of windings of the electromagnetic coil group (5) and the number of radially magnetized permanent magnets (7.1) or the number of intermagnetic permeable blocks (7.3) satisfy: k=m+n, where k, m, and n are all positive integer.

The resonant spring (10) is fixedly connected with the mover, and the stator, mover and resonant spring together form a resonant system; the direction and magnitude of the current of the electromagnetic coil group (4) are adjusted by the electronic control system to realize the required movement.

The moving coil electromagnetic linear actuator based on the compound Halbach array adopts a concentric cylindrical structure, or a flat structure.

A moving coil electromagnetic linear actuator based on a composite Halbach array of the present invention adopts a composite Halbach array, which improves the self-shielding capability of the magnetic circuit, and the permanent magnet can be fixed on a non-magnetic conductive material without additional magnetic The yoke reduces the difficulty of assembly; at the same time, it can significantly improve the power density of the actuator and solve the contradiction between driving requirements and limited installation space. The actuator has higher power density and lower assembly difficulty, and has high research and practical value.

Compared with other technologies, the moving coil electromagnetic linear actuator based on the compound Halbach array proposed by the present invention has the following significant advantages:

(1) It can be used as the executive element of the control system and the driving device. The composite Halbach array is used to improve the power density and reduce the volume, which can effectively solve the contradiction between the driving requirements and the limited installation space, and ensure high-speed, high-precision linear, direct drive and control;

(2) The magnetic circuit of the composite Halbach array is self-shielded and does not require an inner yoke, which reduces the volume and facilitates processing and installation;

(3) For different performance requirements and application goals, the moving coil electromagnetic linear actuator can provide different parameter indicators to ensure the flexibility of the actuator design and a wide range of applications.

The moving coil electromagnetic linear actuator based on the compound Halbach array of the present invention has the advantages of high power density, quick response, easy assembly, and the like, and will bring huge economic benefits after being put into industrial application.

Description of drawings

1 is a schematic diagram of an axial cross-sectional structure of an embodiment of a built-in permanent magnet of the present invention, wherein the direction of the arrow indicates the magnetization direction of the permanent magnet.

FIG. 2 is a schematic diagram of an axial cross-sectional structure of an externally mounted permanent magnet of the present invention, wherein the direction of the arrow indicates the magnetization direction of the permanent magnet.

FIG. 3 is a distribution diagram of magnetic field lines in a steady-state magnetic field finite element simulation of the compound Halbach array of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in Figures 1 to 3, a moving coil electromagnetic linear actuator based on a compound Halbach array is characterized in that it comprises: an end cover (1), a coil bobbin (2), a magnetic yoke (3), an electromagnetic The coil set (4), the main Halbach array layer (5), the auxiliary Halbach array layer (6), the air gap (8), the magnetic isolation shaft (9) and the resonance spring (10), the main features include: a composite Halbach array, It includes the main Halbach array layer (5) and the auxiliary Halbach array layer (6). Auxiliary array layers, which are alternately arranged in close contact with the magnetizing permanent magnets (7.1) and the inter-magnetic permeable blocks (7.3), are fixed on the magnetic isolation shaft (9) as a magnetic source; the yoke (3) and the magnetic source Set to fixed, the gap between the two is an air gap (8), which is used as a stator; the electromagnetic coil group (4) is embedded on the coil bobbin (2), and can perform reciprocating linear motion in the air gap (8), and the actuator ; The composite Halbach array is arranged on one side of the electromagnetic coil group (4), and is close to the main Halbach array layer (5) of the electromagnetic coil group (4).

The electromagnetic coil group (4) is composed of a forward winding coil and a reverse winding coil, and the winding directions of adjacent windings are opposite, wherein the number of forward windings is m, and the number of reverse windings is n, where m and n are both. Positive integer, m=n or m-n=±1.

The outer main Halbach array (5) consists of p axial magnetized permanent magnets (7.1) and k radial magnetized permanent magnets (7.2); the inner auxiliary Halbach array (6) consists of p axial magnetized permanent magnets. The magnet (7.4) is composed of k intermagnetic permeable blocks (7.3); among them, p=k+1, and p and k are both positive integers.

The number of windings of the electromagnetic coil group (5) and the number of radially magnetized permanent magnets (7.1) or the number of inter-magnetic permeable blocks (7.3) satisfy: k=m+n, where k, m, and n are all positive integers .

The resonance spring (10) is fixedly connected with the mover, and the stator, the mover and the resonance spring together form a resonance system; the direction and magnitude of the current of the electromagnetic coil group (4) are adjusted by the electronic control system to realize the required movement.

A moving coil electromagnetic linear actuator based on a compound Halbach array adopts a concentric cylindrical structure, or a flat structure.

As shown in Figure 1, in the built-in permanent magnet type, the number of forward windings and the number of reverse windings m=n=1, the radially magnetized permanent magnet (7.2) and the magnetically permeable block (7.3) per Halbach array layer Taking the number k=2 and the number p=3 of axial permanent magnets (7.1) per Halbach array layer as an example, a moving coil electromagnetic linear actuator based on a compound Halbach array involved in the present invention is described in detail.

The static stable magnetic source is provided by a compound Halbach array. The main Halbach array layer (5) is composed of 2 radially magnetized permanent magnets (7.2) and 3 axially magnetized permanent magnets (7.1) arranged in close proximity to each other. to provide the main air-gap magnetic field of the output force; the auxiliary Halbach array layer (6) consists of 3 axially magnetized permanent magnets (7.1) and 2 inter-magnetic permeable blocks (7.3). The magnetic block (7.3) is sandwiched between every two adjacent axially magnetized permanent magnets (7.1), and is a traditional iron and magnetic array; the magnetic circuit of the auxiliary Halbach array layer (6) will pass through the axially magnetized permanent magnets (7.1). The magnet (7.1) and the intermagnetic permeable block (7.3) go directly back to the main magnetic circuit of the main Halbach array layer (5), as shown in Figure 3. Compared with the traditional Halbach array, the composite Halbach array can effectively reduce the leakage flux and achieve better magnetic self-shielding effect, and the permanent magnet is fixed in the non-magnetic conductive material, which can reduce the assembly difficulty and significantly reduce the volume of the stator. In other words, the use of compound Halbach array can effectively improve the power density of the actuator. More importantly, the magnetic reaction between the main array layer and the auxiliary array layer in the compound Halbach array has the effect of concentrating magnetism and improving the magnetic flux density of the air gap, so it can improve the driving force in a short stroke, which is especially suitable for actuator. At the same time, the current-carrying electromagnetic coil group (5) is subjected to the Lorentz force in the magnetic field generated by the composite Halbach array as the magnetic source, and drives the moving parts to perform linear motion. Different thrusts or powers can be achieved by adjusting the current size The output of the coil, and the coil windings of different winding directions can eliminate the armature reaction generated by the power-on to a certain extent, and improve the stability of the actuator and the electromechanical conversion efficiency.

As a preference, the permanent magnet is placed outside the electromagnetic coil, as shown in Figure 2, the relative volume of the permanent magnet can be increased under the condition of the same motor volume, and the air gap magnetic flux density can be increased. The material directly exchanges heat with the air in the space, which is beneficial to the arrangement of the external cooling system, which can improve the heat dissipation performance and the extreme working capacity of the actuator.

The above is only the preferred embodiment of the present invention, it should be pointed out that: for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (6)

1. A moving coil electromagnetic linear actuator based on a composite Halbach array, characterized in that it comprises: an end cover (1), a coil bobbin (2), a magnetic yoke (3), an electromagnetic coil set (4), The main Halbach array layer (5), the auxiliary Halbach array layer (6), the air gap (8), the magnetic isolation shaft (9) and the resonant spring (10), the main features include: a composite Halbach array, including the main Halbach array layer ( 5) and the auxiliary Halbach array layer (6), the main array layer is composed of axially magnetized permanent magnets (7.1) and radially magnetized permanent magnets (7.2) which are alternately arranged in close contact with each other, and the axially magnetized permanent magnets ( 7.1) and the inter-magnetic magnetic conductive blocks (7.3) are alternately arranged in close contact with each other, and the combination of auxiliary array layers is fixed on the magnetic isolation shaft (9) as a magnetic source; the magnetic yoke (3) and the magnetic source are set to be fixed, both The gap is an air gap (8), which is used as a stator; the electromagnetic coil group (4) is embedded on the coil bobbin (2), and can perform reciprocating linear motion in the air gap (8) to act as an actuator; a compound Halbach array is provided On one side of the electromagnetic coil group (4), the main Halbach array layer (5) close to the electromagnetic coil group (4). 2. A moving coil electromagnetic linear actuator based on a composite Halbach array according to claim 1, wherein the electromagnetic coil group (4) is composed of a forward winding coil and a reverse winding coil, The coils of adjacent windings are wound in opposite directions, wherein the number of forward windings is m, and the number of reverse windings is n, where m and n are both positive integers, and m=n or m-n=±1. 3. A moving coil electromagnetic linear actuator based on a compound Halbach array according to claim 1, characterized in that: the outer main Halbach array (5) consists of p axially magnetized permanent magnets ( 7.1) and k radially magnetized permanent magnets (7.2); the inner layer auxiliary Halbach array (6) is composed of p axially magnetized permanent magnets (7.4) and k intermagnetic magnetic conductive blocks (7.3) ; Among them, p=k+1, p and k are positive integers. 4. A moving coil electromagnetic linear actuator based on a compound Halbach array according to claims 1, 2 and 3, characterized in that: the number of windings of the electromagnetic coil group (5) is the same as the radial charge. The number of magnetic permanent magnets (7.1) or the number of intermagnetic permeable blocks (7.3) satisfies: k=m+n, where k, m, and n are all positive integers. 5. A moving coil electromagnetic linear actuator based on a composite Halbach array according to claims 1 and 3, characterized in that: the resonant spring (10) is fixedly connected to the mover, and the stator and the mover are in harmony The vibrating springs together form a resonance system; the direction and magnitude of the current of the electromagnetic coil group (4) are adjusted by the electronic control system to realize the required movement. 6. A moving coil electromagnetic linear actuator based on a compound Halbach array according to claim 1, wherein the moving coil electromagnetic linear actuator based on a compound Halbach array adopts the same The cylindrical structure of the axis can also be in the form of a flat structure.

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