Windings for primary ironless linear motors

Abstract

The present invention provides a winding for a primary coreless linear motor, which includes a plurality of propulsion coils arranged side by side and at intervals, each propulsion coil is a frame structure surrounded by a first propulsion side, a second propulsion side and two end sides, the first propulsion side and the second propulsion side are two opposite side sides of the propulsion coil, and along the thrust direction, the first propulsion side and the second propulsion side are separated by a pole pitch. The winding for a primary coreless linear motor of the present invention can make the first propulsion side and the second propulsion side of the same propulsion coil correspond to two magnetic fields of different polarities of the superconducting coil, so that the force directions of the first propulsion side and the second propulsion side are the same, avoiding the generation of torsional torque of the same propulsion coil, thereby increasing the service life of the propulsion coil.

Description

Technical Field

[0001] The invention relates to the technical field of linear motors, and in particular to a winding for a primary coreless linear motor. Background Art

[0002] Linear motors are widely used in precision instruments, aerospace, and rail transportation due to their simple structure, no need for intermediate conversion structures, and the ability to directly convert electrical energy into linear electromagnetic thrust. However, linear motors used in high-speed / ultra-high-speed magnetic levitation electromagnetic boost launches require large thrust output under large mechanical air gaps, which cannot be met by ordinary linear induction motors and linear permanent magnet synchronous motors.

[0003] Due to the unique electromagnetic and mechanical properties of superconducting materials, superconducting magnets can generate strong magnetic fields far exceeding those of ordinary magnets, allowing superconducting synchronous linear motors to meet the output capacity of large thrust under large mechanical air gaps. The ground propulsion winding is the core and key component for realizing energy conversion in superconducting linear motors, and the rationality of its design is related to the overall performance of the motor. The unreasonable design of the ground propulsion winding may cause asymmetric motor windings, low winding coefficients and high harmonic content, which in turn leads to a series of problems such as increased losses, electromagnetic vibrations and thrust pulsation. Summary of the invention

[0004] The object of the present invention is to provide a winding for a primary coreless linear motor capable of increasing the service life of a propulsion coil.

[0005] To achieve the above-mentioned purpose, the present invention provides a winding for a primary coreless linear motor, which includes a plurality of propulsion coils arranged side by side and at intervals, each of the propulsion coils is a frame structure surrounded by a first propulsion side, a second propulsion side and two end sides, the first propulsion side and the second propulsion side are two opposite side sides of the propulsion coil, and along the thrust direction, the first propulsion side and the second propulsion side are separated by a pole pitch.

[0006] The winding for the primary coreless linear motor as described above, wherein the first propulsion edge and the second propulsion edge are both V-shaped, and the inner surface of the first propulsion edge and the inner surface of the second propulsion edge are both facing the thrust direction.

[0007] As described above, the winding for the primary coreless linear motor, wherein the angle between the side surface of the first propulsion edge and the vertical surface is the first angle, and the calculation formula of the angle of the first angle is:

[0008] α=arcsin((2τ / v) / (L / 2))

[0009] Wherein, α is the angle between the two side surfaces of the first advancing edge, unit: degree;

[0010] L is the length of the first advancing edge, unit: mm;

[0011] τ is the pole pitch, unit: slot;

[0012] v is the harmonic number to be eliminated.

[0013] As described above, the winding for the primary coreless linear motor, wherein the angle between the side surface of the second propulsion edge and the vertical plane is a second angle, and the angle of the second angle is equal to the angle of the first angle.

[0014] The winding for the primary coreless linear motor as described above, wherein the first propulsion edge and the second propulsion edge have a first preset distance along the suspension direction.

[0015] As described above, the winding for the primary coreless linear motor, wherein two adjacent propulsion coils have a second preset distance along the suspension direction.

[0016] As described above, the winding for the primary coreless linear motor, wherein the calculation formula of the second preset distance is:

[0017] h = 12j / N;

[0018] Wherein, h is the second preset distance, unit: mm;

[0019] j is the first preset distance, unit: mm;

[0020] N is the number of propulsion coils.

[0021] As described above, in the winding for the primary coreless linear motor, the end of the first propulsion edge and the end of the second propulsion edge are both provided with a 90-degree angle.

[0022] The winding for the primary coreless linear motor as described above, wherein a plurality of the propulsion coils are arranged side by side and at equal intervals.

[0023] The winding for a primary coreless linear motor as described above, wherein the end edge is in a straight line shape.

[0024] Compared with the prior art, the advantages of the present invention are as follows:

[0025] In summary, the winding for the primary coreless linear motor of the present invention makes the first propulsion edge and the second propulsion edge correspond to two magnetic fields of different polarities of the superconducting coil respectively by placing the first propulsion edge and the second propulsion edge at a distance of one pole pitch in the thrust direction, so that the first propulsion edge and the second propulsion edge are subjected to the same force direction, thereby avoiding the generation of torsional torque of the same propulsion coil, and thus improving the service life of the propulsion coil;

[0026] The winding for the primary coreless linear motor of the present invention arranges the first propulsion side and the second propulsion side in a V-shaped structure so that the first propulsion side and the second propulsion side are divided into two force-bearing side surfaces with equal side lengths, and both force-bearing side surfaces will generate propulsion force and suspension force, wherein the two suspension forces of the two force-bearing side surfaces of the first propulsion side are equal in magnitude and opposite in direction, that is, the resultant force of the two suspension forces of the two force-bearing side surfaces of the first propulsion side is zero, and similarly, the two suspension forces of the two force-bearing side surfaces of the first propulsion side are equal in magnitude and opposite in direction, that is, the resultant force of the two suspension forces of the two force-bearing side surfaces of the first propulsion side is zero, thereby eliminating the influence on the suspension system, weakening the induced electromotive force in the conductor, and further reducing the no-load back electromotive force harmonic distortion rate;

[0027] The winding for the primary coreless linear motor of the present invention can achieve the purpose of eliminating multiple harmonic contents by adjusting the angles of the first angle and the second angle;

[0028] The winding for the primary coreless linear motor of the present invention can increase the thrust output by adjusting the first preset distance, thereby achieving the purpose of increasing the thrust density under the premise of a constant number of magnets; according to the number of propulsion coils and the first preset distance, the second preset distance is adjusted so that the end edges of two adjacent propulsion coils form a spatial dislocation, which effectively solves the problem of interference and overlap of the end edges of adjacent propulsion coils;

[0029] The winding for the primary coreless linear motor of the present invention is provided with 90-degree folding angles at the ends of the first propulsion edge and the second propulsion edge, so as to facilitate the direction conversion from the first propulsion edge to the second propulsion edge to the end edge. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The following drawings are intended only to illustrate and explain the present invention, and do not limit the scope of the present invention.

[0031] Figure 1 It is a schematic diagram of the assembly structure of the winding and superconducting coil for the primary coreless linear motor of the present invention;

[0032] Figure 2 It is a schematic diagram of the three-dimensional structure of two propulsion coils of different polarities;

[0033] Figure 3 It is a schematic diagram of the main structure of the propulsion coil;

[0034] Figure 4 yes Figure 3 A schematic diagram of the top view of the propulsion coil shown;

[0035] Figure 5 yes Figure 3 A schematic diagram of the side view of the propulsion coil shown;

[0036] Figure 6 It is a schematic diagram of the main structure of the winding for the primary coreless linear motor of the present invention;

[0037] Figure 7 yes Figure 6 A schematic diagram of a winding top view structure for a primary coreless linear motor is shown;

[0038] Figure 8 yes Figure 6 The schematic diagram of the winding side view structure for the primary coreless linear motor shown;

[0039] Fig. 9 It is a structural schematic diagram from another perspective of the propulsion coil in the winding of the primary coreless linear motor of the present invention.

[0040] Description of Figure Numbers:

[0041] 100, propulsion coil; 110, first propulsion edge; 120, second propulsion edge; 130, end edge;

[0042] 200. Superconducting coil;

[0043] 300. Vertical plane. DETAILED DESCRIPTION

[0044] In order to have a clearer understanding of the technical solution, purpose and effect of the present invention, the specific implementation mode of the present invention is now described in conjunction with the accompanying drawings. Among them, the use of adjective or adverbial modifiers "center", "front" and "back" is only to facilitate the relative reference between multiple groups of terms, and does not describe any specific directional restrictions on the modified terms. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0045] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5As shown, the present invention provides a winding for a primary coreless linear motor, which includes a plurality of propulsion coils 100 arranged side by side and at intervals, each propulsion coil 100 is a frame structure surrounded by a first propulsion side 110, a second propulsion side 120 and two end sides 130, the first propulsion side 110 and the second propulsion side 120 are two opposite sides of the propulsion coil 100, and the two end sides 130 are the other two opposite sides of the propulsion coil 100, that is, the first end of the first propulsion side 110 is connected to the first end of the second propulsion side 120 through one end side 130, and the second end of the first propulsion side 110 is connected to the second end of the second propulsion side 120 through the other end side The first propulsion edge 130 is connected to the second propulsion edge 130, and along the thrust direction, the first propulsion edge 110 and the second propulsion edge 120 are separated by a polar distance τ. Specifically, the first propulsion edge 110 adjacent to the superconducting coil 200 is defined as the front propulsion edge, and the second propulsion edge 120 away from the superconducting coil 200 is defined as the rear propulsion edge. When in use, the front propulsion edge faces one of the superconducting coils 200, and the rear propulsion edge faces the other superconducting coil 200, that is, the front propulsion edge and the rear propulsion edge of the same propulsion coil 100 correspond to two magnetic fields of different polarities of the superconducting coil 200, respectively, so that the force directions of the front propulsion edge and the rear propulsion edge are the same, thereby avoiding the generation of torsional moment of the same propulsion coil 100.

[0046] Among them, Figure 2 In the figure, the direction of the hollow arrow is the thrust direction.

[0047] The winding for the primary coreless linear motor of the present invention effectively solves the problem in the prior art that the two propulsion edges of the same propulsion coil 100 are subjected to opposite forces under the superconducting coil 200 of the same polarity, which increases the risk of damage to the propulsion coil 100 and reduces the service life of the propulsion coil 100, by separating the first propulsion edge 110 and the second propulsion edge 120 by a pole pitch in the thrust direction. The front propulsion edge and the rear propulsion edge of the same propulsion coil 100 correspond to the magnetic fields of the superconducting coil 200 of two different polarities, respectively, so that the force directions of the front propulsion edge and the rear propulsion edge are the same, thereby avoiding the generation of torsional torque of the same propulsion coil 100 and improving the service life of the propulsion coil 100.

[0048] Furthermore, a plurality of propulsion coils 100 are arranged side by side and at equal intervals, and the end edges 130 are in a straight line shape to facilitate the arrangement of the propulsion coils 100 .

[0049] Furthermore, considering that the primary winding space magnetic field and the secondary winding space magnetic field of the linear motor will inevitably have high-order harmonics due to the coil type, the synthetic magnetic field in the motor air gap is a non-sinusoidal magnetic field, and the motor no-load back-EMF harmonic distortion rate is high, causing the motor thrust fluctuation and secondary magnet vibration increase. In order to solve this problem, Figure 2 and Figure 3As shown, the first propulsion edge 110 and the second propulsion edge 120 are both V-shaped, and the inner surface of the first propulsion edge 110 and the inner surface of the second propulsion edge 120 are both facing the thrust direction. Specifically, the first propulsion edge 110 and the second propulsion edge 120 are divided into two force-bearing side surfaces with equal side lengths, and both force-bearing side surfaces will generate a propulsion force F x and the suspension force F y , wherein the two suspension forces F of the two force-bearing side surfaces of the first pushing edge 110 are y are equal in magnitude and opposite in direction, that is, the two suspension forces F on the two force-bearing sides of the first pushing edge 110 y The resultant force is zero. Similarly, the two suspension forces F y are equal in magnitude and opposite in direction, that is, the two suspension forces F on the two force-bearing sides of the second pushing edge 120 y The resultant force is zero, thus eliminating the impact on the suspension system, weakening the induced electromotive force in the conductor, and further reducing the no-load back electromotive force harmonic distortion rate.

[0050] Furthermore, the angle between the side surface of the first advancing edge 110 and the vertical surface 300 is a first angle α, and the calculation formula of the first angle α is:

[0051] α=arcsin((2τ / v) / (L / 2))

[0052] Wherein, α is the first angle, unit: degree;

[0053] L is the length of the first advancing edge 110, unit: mm;

[0054] τ is the pole distance;

[0055] v is the harmonic number to be eliminated.

[0056] Specifically, the angle of the first angle α is related to the harmonic order v and the pole pitch τ to be eliminated. To eliminate the Vth harmonic, we only need to make the factor K V is 0, the factor calculation formula is as follows:

[0057]

[0058] Wherein, C is the distance from the midpoint of the first advancing edge 110 to one of the end edges 130, unit: mm;

[0059] When K V = 0, we can get α = arcsin((2τ / v) / (L / 2)).

[0060] Taking the elimination of the third harmonic as an example, At this time, the factor K3=0, the distance from the midpoint of the first advancing edge 110 to one of the end edges 130 is exactly equal to the wavelength of the third spatial harmonic, and the third harmonic electromotive force in the conductor cancels each other out.

[0061] Furthermore, the angle between the side surface of the second pushing edge 120 and the vertical surface 300 is a second angle, and the angle of the second angle is equal to the angle of the first angle α, and both can be calculated using the above formula.

[0062] Further, if Figure 4 , Figure 6 , Figure 7 and Figure 8 As shown, the first propulsion edge 110 and the second propulsion edge 120 have a first preset distance j along the suspension direction. By adjusting the first preset distance j, the thrust output can be increased, thereby achieving the purpose of increasing the thrust density under the premise of a constant number of magnets. The two adjacent propulsion coils 100 have a second preset distance h along the suspension direction, so that the end edges 130 of the two adjacent propulsion coils 100 form a spatial dislocation, thereby avoiding interference and overlap of the end edges 130 of the adjacent propulsion coils 100.

[0063] Among them, Figure 6 In the figure, the direction of the hollow arrow is the suspension direction.

[0064] Furthermore, the calculation formula of the second preset distance h is:

[0065] h = 12j / N;

[0066] Wherein, h is the second preset distance, unit: mm;

[0067] j is the first preset distance, unit: mm;

[0068] N is the number of propulsion coils 100.

[0069] Specifically, Figure 6 As shown, the motor is a symmetrical 18-phase winding and is equivalent to six groups of three-phase motors. Phase A is from A1 to A6, phase B is from B1 to B6, and phase C is from C1 to C6. The number N of the propulsion coils 100 is 6. When the first preset distance j along the suspension direction decreases by 10 mm, the step height of the offset space of the adjacent propulsion coils 100 increases. This can avoid the problem of interference and overlap between the end edges 130 of adjacent propulsion coils 100 when the first preset distance j is reduced.

[0070] Further, if Fig. 9As shown, the ends of the first propulsion edge 110 and the ends of the second propulsion edge 120 are both provided with 90-degree angles, that is, 90-degree angles of Litz wire are formed at the four corners of each propulsion coil 100, so as to facilitate the direction conversion of the first propulsion edge 110 and the second propulsion edge 120 to the end edge 130.

[0071] In summary, the winding for the primary coreless linear motor of the present invention makes the first propulsion edge and the second propulsion edge correspond to two magnetic fields of different polarities of the superconducting coil respectively by placing the first propulsion edge and the second propulsion edge at a distance of one pole pitch in the thrust direction, so that the first propulsion edge and the second propulsion edge are subjected to the same force direction, thereby avoiding the generation of torsional torque of the same propulsion coil, and thus improving the service life of the propulsion coil;

[0072] The winding for the primary coreless linear motor of the present invention arranges the first propulsion side and the second propulsion side in a V-shaped structure so that the first propulsion side and the second propulsion side are divided into two force-bearing side surfaces with equal side lengths, and both force-bearing side surfaces will generate propulsion force and suspension force, wherein the two suspension forces of the two force-bearing side surfaces of the first propulsion side are equal in magnitude and opposite in direction, that is, the resultant force of the two suspension forces of the two force-bearing side surfaces of the first propulsion side is zero, and similarly, the two suspension forces of the two force-bearing side surfaces of the second propulsion side are equal in magnitude and opposite in direction, that is, the resultant force of the two suspension forces of the two force-bearing side surfaces of the second propulsion side is zero, thereby eliminating the influence on the suspension system, weakening the induced electromotive force in the conductor, and further reducing the no-load back electromotive force harmonic distortion rate;

[0073] The winding for the primary coreless linear motor of the present invention can achieve the purpose of eliminating multiple harmonic contents by adjusting the angles of the first angle and the second angle;

[0074] The winding for the primary coreless linear motor of the present invention can increase the thrust output by adjusting the first preset distance, thereby achieving the purpose of increasing the thrust density under the premise of a constant number of magnets; according to the number of propulsion coils and the first preset distance, the second preset distance is adjusted so that the end edges of two adjacent propulsion coils form a spatial dislocation, which effectively solves the problem of interference and overlap of the end edges of adjacent propulsion coils;

[0075] The winding for the primary coreless linear motor of the present invention is provided with 90-degree folding angles at the ends of the first propulsion edge and the second propulsion edge, so as to facilitate the direction conversion from the first propulsion edge to the second propulsion edge to the end edge.

[0076] The above description is only an illustrative specific implementation mode of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any technician in the field without departing from the concept and principle of the present invention should fall within the scope of protection of the present invention. It should also be noted that the various components of the present invention are not limited to the above-mentioned overall application. The various technical features described in the specification of the present invention can be selected one by one or multiple ones can be selected and used in combination according to actual needs. Therefore, the present invention naturally covers other combinations and specific applications related to the invention point of this case.

Claims

1. A winding for a primary coreless linear motor, characterized in that: The winding for the primary coreless linear motor includes a plurality of propulsion coils arranged side by side and at intervals, each of the propulsion coils is a frame structure surrounded by a first propulsion side, a second propulsion side and two end sides, the first propulsion side and the second propulsion side are two opposite side sides of the propulsion coil, and along the thrust direction, the first propulsion side and the second propulsion side are separated by a pole pitch, and the first propulsion side and the second propulsion side have a first preset distance along the suspension direction; The first propulsion edge and the second propulsion edge are both V-shaped, and the inner surface of the first propulsion edge and the inner surface of the second propulsion edge are both facing the thrust direction; The angle between the side surface of the first advancing edge and the vertical surface is the first angle, and the calculation formula of the first angle is: α=arcsin((2τ / v) / (L / 2) ) Wherein, α is the first angle, unit: degree; L is the length of the first advancing edge, unit: mm; τ is the pole pitch, unit: slot; v is the harmonic number to be eliminated; There is a second preset distance between two adjacent propulsion coils along the suspension direction.

2. The winding for a primary coreless linear motor according to claim 1, characterized in that: An included angle between the side surface of the second pushing edge and the vertical surface is a second included angle, and an angle of the second included angle is equal to an angle of the first included angle.

3. The winding for a primary coreless linear motor according to claim 2, characterized in that: The calculation formula of the second preset distance is: h = 12j∕N; Wherein, h is the second preset distance, unit: mm; j is the first preset distance, unit: mm; N is the number of propulsion coils.

4. The winding for a primary coreless linear motor according to claim 1, characterized in that: The end of the first pushing edge and the end of the second pushing edge are both provided with a 90-degree angle.

5. The winding for a primary coreless linear motor according to any one of claims 1 to 4, characterized in that: The plurality of propulsion coils are arranged side by side and at equal intervals.

6. The winding for a primary coreless linear motor according to claim 5, characterized in that: The end edge is in a straight line shape.

Images