A bilateral permanent magnet excited transverse flux switching linear motor

Abstract

The invention discloses a bilateral permanent magnet excitation transverse flux switching linear motor, comprising a primary mechanism and a secondary mechanism, wherein the primary mechanism comprises a plurality of primary units with the same structure, each primary unit comprises a magnetic conductive component, an armature winding and a permanent magnet, wherein N magnetic conductive components and N permanent magnets constitute N magnetic poles and a magnetic conductive yoke, and the armature winding is wound on the magnetic pole; the secondary mechanism comprises a magnetic conductive component, a permanent magnet and a fixed shaft, and the permanent magnet can be embedded in each secondary magnetic conductive component yoke in blocks, or the permanent magnets in the axial direction can be combined into a whole so that they run through each secondary magnetic conductive component, and the magnetization directions of the permanent magnets in adjacent secondary units in the direction of motion are the same. The invention can realize bilateral permanent magnet excitation of the motor, and also maintains the advantages of isolation and decoupling of each phase of the transverse flux linear motor and mutual independence of electromagnetics, so that the motor has the advantages of high efficiency, high torque density, high utilization rate of permanent magnets, flexible design, etc.

Description

Technical Field

[0001] The invention relates to a bilateral permanent magnet excitation transverse flux switching linear motor, belonging to the field of new motor design. Background Art

[0002] When driving a linear motion load, the linear motor eliminates the conversion mechanism of the rotary motor from rotation to linear motion, so it has the advantages of simple overall structure, high position accuracy, fast response speed, low noise, etc., which improves the efficiency of the entire system. In recent years, with the increasing application of linear drives, linear motors have gradually become one of the hot spots of research and development, and have been widely used in military industry, aerospace, rail transportation, electromagnetic catapults and other fields.

[0003] The motion direction of the transverse flux linear permanent magnet motor is perpendicular to the plane where the motor magnetic field path is located. The motor circuit and motor magnetic circuit are relatively independent. Compared with traditional motors, the transverse flux motor has the characteristics of high torque density, flexible design, electromagnetic load decoupling, convenient control, and excellent low-speed characteristics. Its application field is also expanding, especially for low-speed and high-power drive occasions. The transverse flux motor greatly shortens the magnetic circuit length, reduces the amount of ferromagnetic materials and iron loss, and increases the magnetic energy change rate within a certain range, thereby increasing the output of the motor.

[0004] According to the different placement positions of permanent magnets, transverse flux linear motors can be divided into secondary permanent magnet type and primary permanent magnet type, which can be further subdivided into surface mount type and concentrated magnet type. Traditional secondary permanent magnet linear motors have the longest research history, wider influence and application, and more mature application technology at this stage. They are mostly used in long-stroke and large-gap conditions. However, in traditional linear motors, permanent magnets are alternately magnetized along the direction of movement, and there is a problem of magnetic leakage between adjacent permanent magnets, which limits the spatial distribution of permanent magnets and leads to low utilization of permanent magnets. Primary permanent magnet transverse flux linear motors have the advantages of simple structure and easy manufacturing. They can greatly reduce manufacturing costs in long-stroke applications, but because only one side of the permanent magnet is excited, their power density and force density still have room for improvement.

[0005] The primary permanent magnet transverse flux linear motor that has appeared in recent years has the structural characteristics of both transverse flux and flux switching, and has excellent characteristics such as isolation and decoupling, electromagnetic independence, and simple secondary side structure; but the permanent magnet flux interlinked with the winding is small, the thrust density is not high, and the air gap area is small and the air gap magnetic resistance is large; in addition, the amount of copper used is difficult to reduce and the manufacturing cost remains high, so there is still much room for improvement in its structure. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes a bilateral permanent magnet excitation transverse flux switching linear motor. The motor combines a secondary permanent magnet linear motor with a primary permanent magnet linear motor to achieve bilateral permanent magnet excitation, thereby increasing force density and power density. The secondary permanent magnets are embedded in the yoke of the same secondary magnetic conductive component along the circumferential direction, and the magnetization directions of the permanent magnets in adjacent secondary iron cores in the direction of movement are the same, thereby reducing leakage flux and improving the utilization rate of the permanent magnets. The centrally symmetrical air gap layout can eliminate the tangential torque during motor movement, while maintaining the advantages of isolated and decoupled phases and independent electromagnetics of the transverse flux linear motor. The motor has the advantages of high efficiency, high thrust density, flexible design, convenient control, and excellent low-speed characteristics.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A bilateral permanent magnet excitation transverse flux switching linear motor includes a primary mechanism and a secondary mechanism. The primary mechanism includes a plurality of primary units with the same structure, each of which includes a primary magnetic conductive component, an armature winding and a permanent magnet, wherein a tooth of a primary magnetic conductive component forms a magnetic pole through a permanent magnet and a tooth of another primary magnetic conductive component, and the armature winding is wound on the magnetic pole; the secondary mechanism includes a plurality of secondary magnetic conductive components, a fixed shaft and a permanent magnet, each magnetic conductive component has a yoke and a tooth, and the corresponding teeth of two adjacent secondary magnetic conductive components correspond to the teeth of the magnetic conductive components on both sides of the primary magnetic pole, respectively, and the secondary magnetic conductive components are arranged and fixed in sequence on a fixed shaft made of non-magnetic conductive material; and the permanent magnet can be embedded in the yoke of each secondary magnetic conductive component in blocks, or the permanent magnets in the axial direction can be combined into a whole so that it runs through each secondary magnetic conductive component. Regardless of the method used, it is only necessary to ensure that the magnetization direction of the permanent magnets in the adjacent secondary magnetic conductive components in the axial direction is the same and consistent with the magnetic flux flow direction inside the motor.

[0009] The number of magnetic poles and primary magnetic conductive components in the primary unit, and the number of teeth in the secondary magnetic conductive components are equal to the number of poles of the motor, which are all N (N=1, 2, 3, 4, 5...).

[0010] There is an air gap between the teeth of the primary magnetic conductive component and the secondary magnetic conductive component, and the air gap can be constructed into an irregular structure, such as an oblique air gap or an arc-shaped air gap.

[0011] The excitation structure is a bilateral permanent magnet excitation form, the primary permanent magnet is located between every two segmented core teeth of the primary unit, and the magnetic poles of the adjacent permanent magnets that are close to each other are the same.

[0012] The secondary permanent magnet can be integrally inserted into the secondary structure. In this case, N secondary permanent magnets are required, and the length of each permanent magnet is equal to the length of the entire secondary structure.

[0013] The secondary permanent magnets can also be embedded in the yoke of the secondary magnetic conductive component in blocks. In this case, K×N permanent magnets are required, where K is the number of secondary magnetic conductive components and K is a positive integer. The length of each permanent magnet is the same as the thickness of the secondary magnetic conductive component.

[0014] The secondary magnetic conductive component spacing l s and the thickness of the secondary magnetic conductive component τ s The relationship l s ≥τ s .

[0015] Each phase winding in the motor can not only be directly wound around the primary magnetic pole, but also form a loop structure through the primary iron core slot.

[0016] The number of the primary units is an integer multiple of the number of motor phases.

[0017] The linear motor can act as both a generator and a motor.

[0018] The working principle of the present invention is as follows: the magnetic fields generated by the primary and secondary permanent magnets are superimposed on each other in the motor magnetic circuit. When the primary unit is aligned with different secondary magnetic conductive components, the permanent magnet generates magnetic fluxes in different directions in the winding. Therefore, when the motor secondary moves along the direction of motion (i.e., the primary and secondary produce relative displacement), the primary unit and different secondary magnetic conductive components are alternately aligned and changed - the secondary teeth are respectively aligned with the magnetic conductive teeth on both sides of the primary in the primary unit, so that the magnetic flux of the winding passing through the primary magnetic pole changes alternately, and the corresponding induced electromotive force will be induced in the armature winding, and thrust will be generated when a changing current is applied to the winding. By reasonably arranging the spacing between the primary units and the spacing between the secondary magnetic conductive components, and reasonably energizing each phase winding of the primary unit according to the relative position between the primary and secondary in the direction of motion, continuous thrust can be generated.

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

[0020] (1) The motor adopts a transverse flux structure, which has the characteristics of high torque density, flexible design, electromagnetic load decoupling, convenient control, excellent low-speed characteristics, and high efficiency;

[0021] (2) The motor has a simple and compact structure, is easy to assemble, and has high space utilization;

[0022] (3) The motor can adopt an irregular air gap structure to increase the air gap area, so that the mutual inductance of the motor equivalent permanent magnet winding and the armature winding is enhanced; at the same time, because the air gap is centrally symmetrically distributed, it can offset unnecessary tangential torque, reduce the difficulty of fixing the motor and extend the service life of the motor;

[0023] (4) The secondary permanent magnets distributed along the direction of motor movement have the same magnetization direction, which can reduce magnetic leakage between permanent magnets and thus improve the utilization rate of permanent magnets;

[0024] (5) The motor adopts a bilateral permanent magnet excitation structure, with less magnetic leakage between secondary components and high force density and power density;

[0025] (6) The primary winding coil can adopt a circular structure, which reduces the amount of copper used in the motor and reduces the manufacturing cost;

[0026] (7) Each primary unit is independent of each other, and the motor has high reliability and strong fault tolerance; BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1( a ) is a schematic diagram of the structure of a three-phase primary unit four-pole cylindrical slanted air-gap double-sided permanent magnet excited transverse flux linear motor of the present invention;

[0028] FIG1( b ) is a schematic diagram of the structure of a three-phase primary unit four-pole cylindrical slanted air-gap double-sided permanent magnet excited transverse flux linear motor using a winding assembly according to the present invention;

[0029] Figure 2 It is a schematic diagram of the end view structure of a three-phase primary unit four-pole cylindrical slanted air gap double-sided permanent magnet excitation transverse flux linear motor of the present invention and a schematic diagram of the magnetization direction of the primary and secondary permanent magnets;

[0030] FIG3( a ) is a schematic structural diagram of a primary unit of a three-phase primary unit four-pole cylindrical slanted air-gap double-sided permanent magnet excited transverse flux linear motor according to the present invention;

[0031] FIG3( b ) is a schematic diagram of the secondary unit structure of a three-phase primary unit four-pole cylindrical slanted air-gap double-sided permanent magnet excited transverse flux linear motor of the present invention;

[0032] FIG4( a ) is a schematic top view of the secondary structure of a three-phase primary unit four-pole cylindrical slanted air-gap double-sided permanent magnet excited transverse flux linear motor according to the present invention;

[0033] FIG4( b ) is a schematic side view of the secondary structure of a three-phase primary unit four-pole cylindrical slanted air-gap double-sided permanent magnet excited transverse flux linear motor of the present invention;

[0034] FIG5( a ) is a schematic diagram of the block distribution of secondary permanent magnets in a three-phase primary unit four-pole cylindrical slanted air-gap double-sided permanent magnet excited transverse flux linear motor of the present invention;

[0035] FIG5( b ) is a schematic diagram of a three-phase primary unit four-pole cylindrical slanted air-gap double-sided permanent magnet excited transverse flux linear motor with a secondary permanent magnet penetrating a secondary mechanism according to the present invention;

[0036] Figure 6(a) is a schematic diagram of the magnetic flux flow direction when the secondary magnetic conductive component 4 of a three-phase primary unit four-pole cylindrical slanted air gap double-sided permanent magnet excitation transverse flux linear motor of the present invention is aligned with the primary unit;

[0037] Figure 6 (b) is a schematic diagram of the magnetic flux flow direction when the secondary magnetic conductive component 5 of a three-phase primary unit four-pole cylindrical oblique air gap double-sided permanent magnet excitation transverse flux linear motor of the present invention is aligned with the primary unit;

[0038] FIG. 7 is a comparative schematic diagram of different air gap structures used in the present invention, FIG. 7( a ) is a conventional air gap, FIG. 7( b ) is an oblique air gap, and FIG. 7( c ) is an arc-shaped air gap;

[0039] Figure 8 It is a schematic diagram of the overall structure of a three-phase primary unit four-pole cylindrical slanted air gap double-sided permanent magnet excitation transverse flux linear motor of the present invention;

[0040] Among them, 1. primary magnetic conductive material, 2. primary permanent magnet, 3. primary coil winding, 4. secondary magnetic conductive component, 5. secondary magnetic conductive component, 6. secondary permanent magnet, 7. secondary magnetic conductive component fixing shaft. DETAILED DESCRIPTION

[0041] The present invention is further described below in conjunction with the accompanying drawings and embodiments. The motor in the embodiment has 3 phases and 4 poles, and there are 6 secondary magnetic conductive components. At the same time, the air gap between the teeth of the primary magnetic conductive component and the secondary magnetic conductive component is constructed as an oblique air gap.

[0042] As shown in FIG1(a), a schematic diagram of the structure of a three-phase primary unit four-pole cylindrical oblique air gap double-sided permanent magnet excitation transverse flux switching linear motor is shown, which includes a primary and a secondary part. The primary part includes a plurality of primary units with the same structure, each of which includes a primary magnetic conductive component, an armature winding and a permanent magnet, wherein a tooth of a primary magnetic conductive component forms a magnetic pole through a permanent magnet and a tooth of another primary magnetic conductive component, and the armature winding is wound on the magnetic pole; in addition, the armature winding can also form a loop structure in the primary core slot as shown in FIG1(b); the secondary part includes a plurality of secondary magnetic conductive components, a fixed shaft and a permanent magnet, each of the secondary magnetic conductive components has a yoke and a tooth, and the corresponding teeth of two adjacent secondary magnetic conductive components correspond to the teeth of the magnetic conductive components on both sides of the primary magnetic pole, respectively, and the secondary magnetic conductive components are arranged and fixed in sequence on a fixed shaft made of non-magnetic conductive material, and four secondary permanent magnets are placed on the yoke of the secondary magnetic conductive component along the circumferential direction and penetrate the secondary structure along the axial direction. The primary and secondary magnetic conductive materials are made of laminated iron core silicon steel sheets.

[0043] Each primary unit includes a magnetic structure 1, a permanent magnet 2 and a coil winding 3; the secondary part consists of secondary magnetic components 4 and 5 with different installation methods, permanent magnets 6 and a fixed shaft 7. There are 4 secondary permanent magnets running through the secondary structure. The secondary magnetic blocks 4 and 5 each have four teeth. The teeth on the two magnetic blocks are staggered and correspond to the primary magnetic teeth on both sides of the primary magnetic pole. In three phases, the primary units of different phases are spaced 120° apart from each other to form each phase of the motor. The number of primary units and the number of secondary magnetic materials of the motor are not limited to this, and can be increased or decreased according to the actual situation such as the number of phases and length of the motor. The windings of the primary units of the same phase are connected in series or in parallel with each other. The windings in the same primary unit can be connected in series or in parallel with each other.

[0044] Figure 2 The present invention discloses a schematic diagram of the end view structure of a three-phase primary unit four-pole cylindrical oblique air gap bilateral permanent magnet excitation transverse flux switching linear motor and a schematic diagram of the magnetization direction of the primary and secondary permanent magnets. The magnetization directions of the primary permanent magnets and the secondary permanent magnets corresponding to the two sides of the oblique air gap of the motor are opposite to each other, ensuring that the magnetic flux flow direction inside the motor is consistent; at the same time, the magnetization directions of the primary and secondary permanent magnets can be as shown in the figure, or they can be magnetized in the opposite direction, as long as the magnetic poles of the adjacent permanent magnets that are close to each other are the same, and the magnetization directions of the permanent magnets in the adjacent secondary magnetic conductive parts in the direction of movement are consistent. In addition, there are four oblique air gaps uniformly distributed along the circumferential direction between the primary magnetic conductive part and the secondary magnetic conductive part. It can be seen that the air gap A is parallel to the air gap C and is centrally symmetrical, and the air gap B is also parallel to the air gap D and is centrally symmetrically distributed. When the primary unit and the secondary unit of the motor interact with each other, the forces between the two pairs of air gaps pass through the center of the circle and are in opposite directions, which can eliminate the tangential torque when the motor is running, reduce the difficulty of fixing the motor and extend the service life of the motor.

[0045] Fig. 3(a) is a schematic diagram of the primary unit structure of a three-phase primary unit four-pole cylindrical oblique air gap double-sided permanent magnet excitation transverse flux switching linear motor of the present invention. As shown in the figure, four primary permeable cores 1 and four permanent magnets 2 are staggered along the circumferential direction to form four primary magnetic poles, each magnetic pole is composed of a tooth of two permeable cores and a permanent magnet; in addition, the armature winding 3 is wound on each of the above primary magnetic poles.

[0046] Figure 3(b) is a schematic structural diagram of the secondary unit of a three-phase primary unit, four-pole cylindrical oblique air-gap double-sided permanent magnet excitation transverse flux switching linear motor of the present invention, which consists of a secondary magnetic conductive component and a permanent magnet, and each secondary magnetic conductive component includes a magnetic conductive yoke portion and a tooth portion.

[0047] Fig. 4 is a schematic diagram of the secondary structure of a three-phase primary unit four-pole cylindrical oblique air gap double-sided permanent magnet excitation transverse flux switching linear motor of the present invention, wherein Fig. 4 (a) and (b) are respectively a top view and a side view of the secondary structure. The secondary structure includes a magnetic conductive component 4, a magnetic conductive component 5, a secondary permanent magnet 6 and a fixed shaft 7. The magnetic conductive components 4 and 5 have the same structure but different fixing directions, so that the magnetic flux of the motor winding changes when the motor is running.

[0048] FIG5 is a schematic diagram of the secondary permanent magnet distribution of a three-phase primary unit four-pole cylindrical oblique air gap double-sided permanent magnet excitation transverse flux linear motor of the present invention, wherein FIG5(a) is a structure in which the secondary permanent magnets are built into the yoke of each secondary magnetic conductive component in blocks, and the length of each permanent magnet is equal to the stack thickness τ of the secondary magnetic conductive component. s Equal, a total of 24 permanent magnets are required. Figure 5(b) shows the structure when the secondary permanent magnets penetrate the secondary without spacing in the axial direction. The overall length of the secondary permanent magnet is the same as the length of the secondary structure. According to different manufacturing requirements, not only a whole permanent magnet can be used, but also multiple permanent magnets can be spliced ​​and combined into a whole. Regardless of the distribution method used, it is only necessary to ensure that the magnetization direction of the permanent magnets in the adjacent secondary magnetic conductive components in the axial direction is the same and consistent with the magnetic flux flow direction inside the motor.

[0049] Figure 6 (a) is a schematic diagram showing the magnetic flux flow direction when the secondary magnetic conductive component 4 is aligned with the primary unit, Figure 6 (b) shows a schematic diagram of the magnetic flux flow when the secondary magnetic conductive component 5 is aligned with the primary unit. Figure 6 It can be seen that when the secondary moves, from the alignment of the magnetic conductive component 4 with the primary unit to the alignment of the magnetic conductive component 5 with the primary unit, the direction of the winding flux and the direction of the magnetic flux flow inside the motor change, indicating that the motor principle is feasible and the structure is reliable. In addition, the magnetization direction of the secondary permanent magnet is always consistent with the direction of the magnetic flux flow inside the motor, which is conducive to improving the force density and reducing the leakage flux.

[0050] Figure 7 is a schematic diagram of the air gap structure between the teeth of the primary magnetic conductive component of the motor and the corresponding secondary magnetic conductive tooth. Figure 7(a) is a traditional air gap structure, and Figures 7(b) and (c) are irregular air gap structures; Figure 7(b) is an oblique air gap structure, and Figure 7(c) is an arc-shaped air gap structure. The use of an irregular air gap structure can increase the air gap area, which has the effect of reducing the air gap magnetic resistance and reducing leakage magnetic flux.

[0051] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A bilateral permanent magnet excitation transverse flux switching linear motor, characterized by: It includes two parts, primary and secondary. The primary part includes several primary units with the same structure. Each primary unit includes a primary magnetic conductive component, an armature winding and a permanent magnet. Among them, a tooth of a primary magnetic conductive component forms a magnetic pole through a permanent magnet and a tooth of another primary magnetic conductive component, and the armature winding is wound on the magnetic pole; the secondary part includes several secondary magnetic conductive components, a fixed shaft and a permanent magnet. The magnetic conductive components all have yokes and teeth. The corresponding teeth of two adjacent secondary magnetic conductive components correspond to the teeth of the magnetic conductive components on both sides of the primary magnetic pole respectively. The secondary magnetic conductive components are arranged and fixed in sequence on the fixed shaft made of non-magnetic conductive material, and the permanent magnets are embedded in the yokes of each secondary magnetic conductive component in blocks, or the permanent magnets in the axial direction are combined into a whole so that they run through each secondary magnetic conductive component, ensuring that the magnetization directions of the permanent magnets in the adjacent secondary magnetic conductive components in the axial direction are the same and consistent with the flow direction of the magnetic flux inside the motor; the primary and secondary magnetic conductive materials are laminated by iron core silicon steel sheets.

2. A bilateral permanent magnet excitation transverse flux switching linear motor as claimed in claim 1, characterized in that: The number of magnetic poles and primary magnetic conductive components in the primary unit and the number of teeth in the secondary magnetic conductive components are the same as the number of poles of the motor, which are both N, and N is a positive integer.

3. A bilateral permanent magnet excitation transverse flux switching linear motor as claimed in claim 1, characterized in that: The permanent magnets are combined into a whole along the axial direction and penetrate the secondary mechanism. The number of secondary permanent magnets is also the same as the number of motor poles N, and the length of each permanent magnet is equal to the length of the entire secondary structure; or the secondary permanent magnets are divided into blocks and built into the yoke of each secondary magnetic conductive component. The number of secondary permanent magnets is K×N, K is the number of secondary magnetic conductive components on the fixed shaft, and the length of each permanent magnet is equal to the thickness of the secondary magnetic conductive component.

4. The bilateral permanent magnet excitation transverse flux switching linear motor according to claim 1, characterized in that: The air gap structure between the teeth of the primary magnetic conductive component and the secondary magnetic conductive component includes an oblique air gap structure or an arc-shaped air gap structure.

5. A bilateral permanent magnet excitation transverse flux switching linear motor as claimed in claim 1, characterized in that There is an air gap between the teeth of the primary magnetic conductive component and the secondary magnetic conductive component, and the air gaps are distributed symmetrically between the two.

6. A bilateral permanent magnet excitation transverse flux switching linear motor as claimed in claim 1, characterized in that : Each phase winding in the motor is directly wound around the primary magnetic pole, or forms a loop structure through the primary iron core slot.

7. A bilateral permanent magnet excitation transverse flux switching linear motor as claimed in claim 1, characterized in that : The secondary magnetic conductive component spacing l s and the thickness of the secondary magnetic conductive component τ s The relationship is l s ≥τ s .

8. The double-sided permanent magnet excitation transverse flux switching linear motor according to claim 1, characterized in that :The linear motor can be used as both a generator and a motor.

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