A guide rail-free self-positioning linear electromagnetic actuator

Abstract

The application discloses a guide rail-free self-positioning linear electromagnetic actuator, which comprises a rotor and a stator; the rotor moves linearly along the stator; the stator comprises a stator base plate, a positioning coil and a driving coil; the positioning coil is located on one side of the stator base plate; the driving coil is located on the other side of the stator base plate; and the driving coil comprises an A-phase coil and a B-phase coil. The application generates current by controlling the electrification of the A-phase coil and the B-phase coil, and due to the action of the Lorentz force, an acting force in the movement direction, defined as the X direction, is generated on the rotor, and the rotor moves under the action of the acting force to reach a specified position. The direction of the magnetic field generated after the electrification of the positioning coil is consistent with the magnetization direction of the permanent magnet of the rotor, and the direction is defined as the -Z direction. When the actuator is subjected to external disturbance in the non-X direction, the positioning coil generates a restoring force on the rotor to make the rotor return to the equilibrium position, and the positioning coil plays the role of a non-contact guide rail.

Description

Technical Field

[0001] This invention relates to a linear electromagnetic actuator, and more particularly to a guide rail-less self-positioning linear electromagnetic actuator. Background Technology

[0002] Miniaturized electromagnetic actuators with feature dimensions on the order of millimeters are widely used in fields such as biomedicine and consumer electronics, such as the camera rotation mechanism in a gastroscope capsule and the lens driver in a smartphone. As electromagnetic actuators become smaller and smaller, the machining and assembly precision of the supporting components between the rotor and stator, such as bearings and guide rails, are facing increasingly higher requirements. Reducing friction and wear between the rotor and guide rails is one of the key technical points that needs to be addressed.

[0003] Reference 1 (MV Shutov, et al., A microfabricated electromagnetic linear synchronous motor, Sens. Actuators APhys. 121 (2005) 566–575, http: / / dx.doi.org / 10.1016 / j.sna.2005.03.022.) used wet etching of single-crystal silicon to fabricate a dovetail groove guide rail, which has a complex design and limited material options. <100> Oriented single-crystal silicon. Reference 2 (C. Zhi, et al., Fabrication and characterization of micro electromagnetic linear actuators, J. Micromech. Microeng. 30 (2020) 125011) used a design similar to a sliding guide rail and conducted experimental verification, ensuring the versatility of the processing. However, the rotor inevitably collides with the guide rail and "jamming" occurs. Reference 3 (C. Zhi, et al., A self-attachable and self-alignable electromagnetic linear actuator, J. Micromech. Microeng. 31 (2021) 015001) proposed a non-contact magnetic guide rail. By using arrayed magnets and arrayed iron cores, self-adhesion and self-positioning are achieved on the one hand, and collisions and friction of the guide rail are effectively avoided on the other hand. However, due to the arrangement of the arrayed permanent magnets and iron cores, the thrust on the rotor fluctuates, and the force between the permanent magnets and the iron core cannot be adjusted. At the same time, the processing of the arrayed iron core structure is relatively complex. Summary of the Invention

[0004] Based on the above description, the present invention proposes a guide rail-less self-positioning linear electromagnetic actuator. A drive coil is provided on one side of the stator substrate, and a positioning coil is provided on the corresponding other side. The rotor moves linearly along the stator substrate on the front side of the stator substrate. The drive coil provides the driving force for the rotor movement. The positioning coil ensures that the rotor is attracted to the stator substrate and at the same time ensures that the rotor moves in a specified direction.

[0005] The technical solution adopted is: a guide rail-less self-positioning linear electromagnetic actuator, including a rotor and a stator; the rotor moves linearly along the front of the stator.

[0006] The stator includes a stator substrate, a positioning coil, and a drive coil; the positioning coil is located on one side of the stator substrate; the drive coil is located on the other side of the stator substrate; the positioning coil is a planar spiral coil.

[0007] The drive coil includes an A-phase coil and a B-phase coil; the A-phase coil and the B-phase coil are intertwined but do not cross each other; the A-phase coil includes several A-phase coil units arranged in a periodic manner, and the start and end of adjacent A-phase coil units are connected; the B-phase coil includes several B-phase coil units arranged in a periodic manner, and the start and end of adjacent B-phase coil units are connected.

[0008] The B-phase coil starts from its starting point, passes through one side of the stator substrate, goes through the stator substrate, travels a certain distance on the other side of the stator substrate, then passes through the stator substrate again, and loops back to one side of the stator substrate in a serpentine pattern. This process is repeated until the end of the B-phase coil.

[0009] The A-phase coil starts from its starting point on the same side of the stator substrate as the starting point of the B-phase coil. It passes between the B-phase coils, crosses the stator substrate, travels a certain distance on the other side of the stator substrate, crosses the stator substrate again, and circles back to one side of the stator substrate in a serpentine pattern. This process is repeated until the end point of the A-phase coil.

[0010] The rotor includes a magnetically conductive rotor substrate and a permanent magnet; the magnetically conductive rotor substrate is serrated, forming concave and convex portions; the concave and convex portions are evenly spaced; the concave portions are embedded with permanent magnets; the permanent magnets are linear.

[0011] Furthermore, the drive coil is located on the front side of the stator substrate; the positioning coil is located on the back side of the stator substrate; and the rotor moves linearly along the front side of the stator substrate.

[0012] Furthermore, the positioning coil is located on the front side of the stator substrate; the drive coil is located on the back side of the stator substrate; and the rotor moves linearly along the front side of the stator substrate.

[0013] Furthermore, the A-phase coil and the B-phase coil are at the same height.

[0014] Furthermore, the distance between the A-phase coil units is the same as the distance between the B-phase coil units, which is 'a'.

[0015] Furthermore, the distance between the wires of phase A coil and the wires of phase B coil is 0.5a.

[0016] Furthermore, the widths of the concave and convex portions in the magnetic rotor substrate are equal; and the distance between them and the A-phase coil unit is the same as the distance between them and the B-phase coil unit, which is a.

[0017] Furthermore, the width of the permanent magnet is the same as the distance between the A-phase coil unit and the B-phase coil unit, which is 'a'.

[0018] The rotor in this invention comprises a linear permanent magnet and a magnetically conductive rotor substrate, with the linear permanent magnet embedded in the magnetically conductive substrate. The stator includes a stator substrate, drive coils, and positioning coils; the drive coils and positioning coils are located on the upper and lower layers of the stator substrate, respectively. The function of the drive coils is to provide the driving force during rotor movement. The function of the positioning coils is to ensure that the rotor is attracted to the stator substrate and to ensure that the rotor moves in a specified direction, acting as a "guide rail". The drive coils include an A-phase coil and a B-phase coil; the A-phase coil and the B-phase coil have a serpentine configuration, with equal spacing between adjacent bent lines (defined as 'a' without loss of generality); the bent lines of the A-phase coil and the B-phase coil on the other side of the stator substrate are located on corresponding sides; the spacing between the mutual lines of the A-phase coil and the B-phase coil is 0.5a; to avoid short circuits caused by the crossing of the A and B phase coils, the coils are connected using a back-side via process.

[0019] The positioning coil and drive coil can be mounted on the stator substrate using integrated manufacturing methods.

[0020] By controlling the magnitude and phase of the current flowing through the A-phase coil and the B-phase coil, current is generated. Due to the Lorentz force, a force in the X direction is generated on the rotor, and the rotor moves under this force to reach the specified position.

[0021] The magnetic field generated by the positioning coil after it is energized is in the same direction as the magnetization direction of the rotor permanent magnet (defined as the -Z direction). Due to the presence of the positioning coil, when the actuator is subjected to external disturbances in a direction other than X, the positioning coil will generate a restoring force on the rotor to return it to the equilibrium position. The positioning coil acts as a non-contact "guide rail". Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention;

[0023] Figure 2 This is a schematic diagram of the explosion state of the present invention;

[0024] Figure 3 This is a schematic diagram of the rotor structure in this invention;

[0025] Figure 4 This is a front view of the stator in this invention, with the drive coil located on the front of the stator;

[0026] Figure 5 This is a schematic diagram of the back side of the stator in this invention, with the positioning coil located on the front and back sides of the stator;

[0027] Figure 6 This is a schematic diagram of the drive coil structure in this invention.

[0028] Figure 7 yes Figure 1 Cross-sectional view;

[0029] Figure 8 This is a schematic diagram of the rotor being energized in phase A drive coil at position 1 in this invention;

[0030] Figure 9 This is a schematic diagram of the rotor being energized in phase B drive coil at position 2 in this invention;

[0031] Figure 10 This is a schematic diagram of the rotor being energized in phase A drive coil at position 3 in this invention;

[0032] Figure 11 This is a schematic diagram of the rotor being energized in phase B drive coil at position 4 in this invention;

[0033] Figure 12 This is a schematic diagram showing the energization of phase A and phase B drive coils at different positions of the rotor in this invention;

[0034] Figure 13 This is a schematic diagram of the rotor and positioning coil in this invention;

[0035] Figure 14 This is a schematic diagram showing the magnetization direction of the permanent magnet in the rotor and the energizing direction of the positioning coil in this invention;

[0036] Figure 15 This is a schematic diagram of the force exerted by the positioning coil on the rotor when it moves in the Y direction in this invention;

[0037] Figure 16 This is a schematic diagram illustrating the changes in force and torque exerted by the positioning coil on the rotor when it moves in the Y direction and rotates in the Z direction in this invention. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0039] See Figures 1 to 7 A guide rail-free self-positioning linear electromagnetic actuator includes a rotor 2 and a stator 1; the rotor 2 moves linearly along the front of the stator 1.

[0040] The stator 1 includes a stator substrate 11, a positioning coil 12 and a drive coil 13; the positioning coil 12 is located on one side of the stator substrate 11; the drive coil 13 is located on the other side of the stator substrate; the positioning coil 12 is a planar spiral coil.

[0041] Specifically, the drive coil may be located on the front side of the stator substrate; the positioning coil may be located on the back side of the stator substrate; and the rotor may move in a straight line along the front side of the stator substrate.

[0042] Alternatively, the positioning coil may be located on the front side of the stator substrate; the drive coil may be located on the back side of the stator substrate; and the rotor may move linearly along the front side of the stator substrate.

[0043] The drive coil 13 includes an A-phase coil 131 and a B-phase coil 132; the A-phase coil and the B-phase coil are intertwined and do not cross each other; the A-phase coil 131 includes several A-phase coil units arranged in a periodic manner, and the start and end of each adjacent coil unit are connected; the B-phase coil includes several B-phase coil units arranged in a periodic manner, and the start and end of each adjacent B-phase coil unit are connected; the distance between individual A-phase coils is the same as the distance between individual B-phase coils, which is a; the distance between the lines of the A-phase coil and the lines of the B-phase coil is 0.5a.

[0044] The B-phase coil 132 starts from its starting point, passes through one side of the stator substrate 11, goes through the stator substrate 11, travels a certain distance on the other side of the stator substrate, passes through the stator substrate again, and goes back to one side of the stator substrate in a serpentine pattern. This process is repeated until the end of the B-phase coil.

[0045] Phase A coil 131 starts from its starting point and is on the same side of the stator substrate 11 as the starting point of Phase B coil 132. It passes between Phase B coils, passes through the stator substrate, travels a certain distance on the other side of the stator substrate, passes through the stator substrate again, and returns to one side of the stator substrate in a serpentine pattern. This process is repeated until the end point of Phase A coil.

[0046] The heights of phase A coil 131 and phase B coil 132 are equal; their heights are the same as the thickness of the stator substrate 11.

[0047] The rotor 2 includes a magnetic rotor substrate 21 and a permanent magnet 22; the magnetic rotor substrate 21 is serrated, forming concave and convex portions; the concave and convex portions are evenly spaced; the permanent magnet 22 is embedded in the concave portion; the permanent magnet is linear.

[0048] The widths of the concave and convex portions in the magnetic rotor substrate 21 are equal; and the distance between them and a single coil of phase A is the same as the distance between a single coil of phase B, which is 'a'. The width of the permanent magnet 22 is also 'a'.

[0049] like Figure 8 As shown, when the rotor is at position 1, it rotates in the X direction. Without loss of generality, the magnetization direction of the permanent magnet is defined as along the -Z direction. At this time, the positioning coil is energized; at this time, the A-phase coil is energized. The current in phase A coil is perpendicular to the paper and outwards. The current in phase A coil is perpendicular to the paper and inwards; due to the Lorentz force, a force to the right will be generated on the rotor; the rotor will move to the right by 0.5a under this force, reaching position 2, as shown. Figure 9 As shown.

[0050] like Figure 9 As shown, to ensure the rotor continues to rotate in the X direction, the B-phase coil at position 2 is energized. The current in phase B coil is perpendicular to the paper and outwards. The current in phase B coil is perpendicular to the paper and inwards; due to the Lorentz force, a force to the right will be generated on the rotor; the rotor will move to the right by 0.5a under this force, reaching position 3, as shown. Figure 10 As shown.

[0051] like Figure 10 As shown, to ensure the rotor continues to rotate in the X direction, the A-phase coil at position 3 is energized. The current in phase A coil is perpendicular to the paper and outwards. The current in phase A coil is perpendicular to the paper and pointing inwards. Due to the Lorentz force, a force to the right will be generated on the rotor; the rotor will move to the right by 0.5a under this force, reaching position 4, as shown. Figure 11 As shown.

[0052] like Figure 11 As shown, to ensure the rotor continues to rotate in the X direction, the B-phase coil at position 4 is energized. The current in phase B coil is perpendicular to the paper and outwards. The current in phase B coil is perpendicular to the paper and pointing inwards. Due to the Lorentz force, a force to the right is generated on the rotor. Under this force, the rotor will move to the right for 0.5a, reaching the next position, the same as position 1; that is, completing one cycle of 2a, and then... Figure 7 The initial energizing sequence is performed, and the rotor continues to rotate in the X direction until it reaches the desired position.

[0053] like Figure 12As shown, this is a schematic diagram of the energization of the drive coil at different positions in order to maintain the rotor's movement along the X direction; as the position moves, the current flowing through the A-phase and B-phase coils also changes sinusoidally, with a period of 2a.

[0054] like Figure 13 The diagram shows a rotor and a positioning coil. When the magnetization direction of the rotor permanent magnet is -Z, a current is passed through the positioning coil as shown in the diagram. The current is clockwise, and the magnetic field it generates is in the same direction as the rotor magnetic field. The force it generates on the rotor is in the -Z direction.

[0055] like Figure 14 As shown, when the rotor is in the position shown in the figure, it receives a force in the -Z direction, and the rotor can self-adhere to the stator surface.

[0056] like Figure 15 As shown, when the rotor is subjected to external disturbances on the stator base plate and displaces along the Y direction, without loss of generality, when the rotor deviates towards the positive Y direction, it experiences a restoring force along the -Y direction generated by the positioning coil. The rotor has the ability to resist external disturbances and return to its equilibrium position. Similarly, when the rotor experiences an external disturbance causing rotation along the Z direction, it will experience a restoring torque from the positioning coil, causing it to return to its equilibrium position. Figure 12 The equilibrium position is shown.

[0057] like Figure 16 As shown, the force on the rotor varies with the position of the disturbance in the Y direction ΔY and the angle of the disturbance in the Z direction Δθ. Z At this time, the rotor is subjected to the restoring force and restoring torque of the positioning coil. As shown in the figure, the force in the Y direction changes with ΔY with a negative slope, meaning that the positioning coil allows the rotor to be stabilized at the position where ΔY equals 0; the torque in the Z direction allows the rotor to be stabilized at Δθ. Z The position equal to 0; that is, the positioning coil acts as a non-contact "guide rail".

Claims

1. A guide rail-less self-positioning linear electromagnetic actuator, characterized in that... It includes a rotor and a stator; the rotor moves linearly along the stator; The stator includes a stator substrate, a positioning coil, and a drive coil; the positioning coil is located on one side of the stator substrate; the drive coil is located on the other side of the stator substrate; the positioning coil is a planar spiral coil. The driving coil includes an A-phase coil and a B-phase coil; the A-phase coil and the B-phase coil are intertwined but do not cross each other; the A-phase coil includes several A-phase coil units arranged in a periodic manner, with the start and end of adjacent A-phase coil units connected; the B-phase coil includes several B-phase coil units arranged in a periodic manner, with the start and end of adjacent B-phase coil units connected; the A-phase coil and the B-phase coil are separated by half a cycle, which is 'a'; one cycle is 2a. The B-phase coil starts from its starting point, passes through one side of the stator substrate, goes through the stator substrate, travels a certain distance on the other side of the stator substrate, and then passes through the stator substrate again, returning to one side of the stator substrate in a serpentine pattern. This process is repeated until the end of the B-phase coil. The A-phase coil starts from its starting point on the same side of the stator substrate as the starting point of the B-phase coil; it passes between the B-phase coils, passes through the stator substrate, travels a certain distance on the other side of the stator substrate, passes through the stator substrate again, and circles back to one side of the stator substrate in a serpentine pattern, repeating this process until the end point of the A-phase coil. The rotor includes a magnetically conductive rotor substrate and a permanent magnet; the magnetically conductive rotor substrate is serrated, forming concave and convex portions; the concave and convex portions are evenly spaced; the permanent magnet is embedded in the concave portion; the permanent magnet is linear.

2. The guide rail-less self-positioning linear electromagnetic actuator according to claim 1, characterized in that... The drive coil is located on the front side of the stator substrate; the positioning coil is located on the back side of the stator substrate; the rotor moves linearly along the front side of the stator substrate.

3. A guide rail-less self-positioning linear electromagnetic actuator according to claim 1, characterized in that... The positioning coil is located on the front side of the stator substrate; the driving coil is located on the back side of the stator substrate; the rotor moves linearly along the front side of the stator substrate.

4. A guide rail-less self-positioning linear electromagnetic actuator according to claim 1, characterized in that... The A-phase coil and the B-phase coil are of equal height.

5. A guide rail-less self-positioning linear electromagnetic actuator according to claim 1, characterized in that... The distance between the A-phase coil units is the same as the distance between the B-phase coil units, which is 'a'.

6. A guide rail-less self-positioning linear electromagnetic actuator according to claim 1, characterized in that... The distance between the wires of phase A coil and phase B coil is 0.5a.

7. A guide rail-less self-positioning linear electromagnetic actuator according to claim 1, characterized in that... The widths of the concave and convex portions in the magnetic rotor substrate are equal; and the distance between them and a single coil of phase A is the same as the distance between them and a single coil of phase B, which is a.

8. A guide rail-less self-positioning linear electromagnetic actuator according to claim 1, characterized in that... The width of the permanent magnet is the same as the distance between the A-phase coil unit and the B-phase coil unit, which is denoted as a.

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