Linear electromagnetic actuator with integrated sensor

Abstract

The application discloses a linear electromagnetic actuator integrating sensing and executing, which comprises a rotor, a guide rail and a stator; the guide rail is installed on the stator; the guide rail is provided with a movable groove, and the rotor can move in the movable groove. The stator comprises a stator base plate, an inductor coil and a driving coil; the inductor coil is integrated on the back of the stator base plate, and the driving coil is installed on the front of the stator base plate. The inductor coil and the magnetically conductive rotor base plate form an inductor system, when the rotor moves under the action of the driving coil, the inductance will periodically change with the position of the rotor. The position detection of the motor can be carried out based on the periodic change of the inductance, and the speed feedback control of the electromagnetic actuator is facilitated.

Description

Technical Field

[0001] This invention relates to a linear electromagnetic actuator, and more particularly to a linear electromagnetic actuator that integrates sensing and actuation. Background Technology

[0002] Miniaturized electromagnetic actuators with feature sizes 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. They consist of a moving part (rotor) and a stationary part (stator). The rotor position of an electromagnetic actuator is typically based on a laser displacement sensor (a microfabricated electromagnetic linear synchronous motor and a self-attachable and self-alignable micro electromagnetic linear actuator) or a magnetoresistive sensor (fabrication and characterization of micro electromagnetic linear actuators). As electromagnetic actuators become increasingly smaller, laser displacement sensors and magnetoresistive sensors, as functional devices, are difficult to miniaturize and integrate with electromagnetic actuators. Summary of the Invention

[0003] Based on the above description, this invention proposes a linear electromagnetic actuator integrating sensing and execution. A drive coil and an inductor coil are respectively laid on the front and back of the stator substrate. The inductor coil and the magnetic rotor substrate constitute an inductance system. When the rotor moves under the action of the drive coil, the inductance will change periodically with the change of the rotor position. The position detection of the motor can be performed based on the periodic change of the inductance, which facilitates the speed feedback control of the electromagnetic actuator.

[0004] The technical solution adopted is: a linear electromagnetic actuator integrating sensing and execution, including a rotor, a guide rail and a stator; the guide rail is mounted on the stator; a movable slot is opened on the guide rail, and the rotor is placed in the movable slot and can move along the movable slot.

[0005] The stator includes a stator substrate, an inductor coil, and a drive coil. The inductor coil is integrated on the back side of the stator substrate, and the drive coil is integrated on the front side of the stator substrate. The inductor coil is composed of several unit coils connected together, and the connection method of the unit coils satisfies that the magnetic field lines generated by adjacent unit coils are opposite. The beginnings of adjacent unit coils are connected by a first wire bridge. The end portions of adjacent unit coils are connected by a second wire bridge. The first and second wire bridges have the same structure, are n-shaped, and pass through the stator substrate respectively, located on the front side of the stator substrate.

[0006] The rotor includes a magnetic rotor substrate and a permanent magnet; the magnetic 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.

[0007] Furthermore, the widths of the recesses and protrusions in the magnetic rotor substrate are equal.

[0008] Furthermore, the inductor coils are evenly distributed on the stator substrate; the width of a single unit coil is equal to the width of the spacing between them.

[0009] Furthermore, the unit coil is formed by arranging a single wire in a U-shape.

[0010] Furthermore, the width of the inductor coil is smaller than the width of the stator substrate; the width of the drive coil is smaller than the width of the inductor coil.

[0011] Furthermore, an inductor coil is arranged on the front side of the stator substrate; a drive coil is arranged on the back side of the stator substrate.

[0012] 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. Guide rails are located on both sides of the rotor to ensure that the rotor moves in a straight line. The stator includes a stator substrate, a drive coil, and an inductance detection coil; the drive coil and the inductance coil are located on the upper and lower layers of the stator substrate, respectively. The inductance coil and the magnetically conductive rotor substrate constitute an inductance system. When the rotor moves under the action of the drive coil, the inductance changes periodically with the rotor position. Based on the periodic change in inductance, the position of the motor can be detected, facilitating speed feedback control of the electromagnetic actuator.

[0013] In this invention, both the driving coil and the inductance detection coil are compatible with microfabrication technology and can be integrated into one unit. This simplifies the structure and avoids the drawback of traditional position detection methods being difficult to miniaturize due to insufficient integration. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention;

[0015] Figure 2 This is a schematic diagram of the explosion state of the present invention;

[0016] Figure 3 This is a schematic diagram of the rotor structure in this invention;

[0017] Figure 4 This is a schematic diagram of the stator structure in this invention (with the stator made transparent);

[0018] Figure 5 This is a schematic diagram of the structure of the inductor coil in this invention;

[0019] Figure 6yes Figure 1 A schematic diagram of the AA cross-section; a diagram showing the relative positions of the inductor coil and the rotor;

[0020] Figure 7 This is the position where the inductor coil and the rotor magnetic substrate have the maximum magnetic flux interaction in this invention;

[0021] Figure 8 This refers to the position where the inductor coil and the rotor magnetic substrate have the minimum magnetic flux interaction in this invention;

[0022] Figure 9 This refers to the change in inductance detected at the inductor coil during the rotor movement in this invention. Detailed Implementation

[0023] 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.

[0024] See Figures 1 to 6 A linear electromagnetic actuator integrating sensing and actuation is disclosed, comprising a rotor 1, a guide rail 2, and a stator 3. The rotor 1 includes a magnetic rotor substrate 11 and linear permanent magnets 12; the magnetic rotor substrate 11 is serrated, forming concave and convex portions; the concave and convex portions are evenly spaced; the linear permanent magnets 12 are embedded in the concave portions. The width of the concave portion in the magnetic rotor substrate 11 is W1, and the width of the convex portion is W2, where W1 and W2 are equal.

[0025] The guide rail 2 is mounted on the stator base plate 31 of the stator 3; the guide rail 2 has a movable groove 21, and the rotor moves along the movable groove 21.

[0026] The stator 3 includes a stator substrate 31, an inductor coil 32, and a drive coil 33; the inductor coil 32 is integrated on the back side of the stator substrate, and the drive coil 33 is integrated on the front side of the stator substrate; the inductor coil is composed of several unit coils connected together, and the connection method of the unit coils satisfies that the magnetic field lines generated by adjacent unit coils are opposite; such as Figure 5 As shown by the arrow, the arrow indicates the direction of current flow, and the direction of the generated magnetic flux can be determined using the right-hand rule. The beginnings of adjacent unit coils are connected by a first wire bridge 34; the ends of adjacent unit coils are connected by a second wire bridge 35; the first and second wire bridges have the same structure, are n-shaped, and pass through the stator substrate, respectively, and are located on the front side of the stator substrate.

[0027] Depending on the actual working conditions, the inductor coil can be arranged on the front side of the stator substrate, and the drive coil can be arranged on the back side of the stator substrate.

[0028] The width of a single inductor coil is W3, and the width of the gap between them is W4, with W3 and W4 being equal.

[0029] The width of the recess 111 in the magnetic rotor substrate 11 is W1, the width of the protrusion is W2, the width of a single inductor coil is W3, and the width of the spacing between them is W4. All four widths are equal.

[0030] W1 = W2 = W3 = W4

[0031] The width of the inductor coil 32 is smaller than the width of the magnetic stator substrate 31; the width of the drive coil 33 is smaller than the width of the inductor coil 32.

[0032] like Figure 7 As shown, the position of the inductor coil and the rotor magnetic substrate at the point of maximum magnetic flux interaction (defined as position 1) is shown. The arrows in the figure indicate the direction of magnetic flux flow. It can be seen that the magnetic flux generated by adjacent coils is mutually enhanced by the rotor magnetic substrate, that is, the inductance is strongest at this point. Figure 7 middle, The current in the inductor is perpendicular to the paper and outwards. The current in the inductor is perpendicular to the paper and inwards.

[0033] Figure 8 This is the position where the inductor coil and the magnetic substrate have the least magnetic flux interaction (defined as position 2). The arrow in the figure indicates the direction of magnetic flux flow, and the inductance is weakest at this point. Figure 8 middle, The current in the inductor is perpendicular to the paper and outwards. The current in the inductor is perpendicular to the paper and inwards.

[0034] Figure 9 The display shows the change in inductance detected at the inductor coil during rotor movement. The inductance is maximum at position 1 and minimum at position 2. The rotor position can be determined by checking the inductance.

[0035] By integrating an inductor coil on the stator substrate, the rotor position can be obtained by detecting the inductance with the rotor magnetic substrate. This achieves an integrated sensing and actuation electromagnetic actuator.

Claims

1. A linear electromagnetic actuator integrating sensing and actuation, characterized in that... It includes a rotor, a guide rail, and a stator; the guide rail is mounted on the stator; the guide rail has a movable slot, and the rotor is placed in the movable slot and can move along the movable slot; The stator includes a stator substrate, an inductor coil, and a drive coil. The inductor coil is integrated on the back side of the stator substrate, and the drive coil is integrated on the front side of the stator substrate. The inductor coil is composed of several unit coils connected together, and the connection method of the unit coils satisfies that the magnetic field lines generated by adjacent unit coils are opposite. The beginnings of adjacent unit coils are connected by a first wire bridge, and the end portions of adjacent unit coils are connected by a second wire bridge. The first and second wire bridges have the same structure, are n-shaped, and pass through the stator substrate, respectively, and are located on the front side of the stator substrate. 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 widths of the concave and convex portions are equal; the permanent magnet is embedded in the concave portion; the permanent magnet is linear.

2. The linear electromagnetic actuator integrating sensing and actuation according to claim 1, characterized in that... The inductor coils are evenly distributed on the stator substrate; the width of a single unit coil is equal to the width of the spacing between them.

3. A linear electromagnetic actuator integrating sensing and actuation according to claim 1, characterized in that... The unit coil is formed by arranging a single wire in a U-shape.

4. A linear electromagnetic actuator integrating sensing and actuation according to claim 1, characterized in that... The width of the inductor coil is smaller than the width of the stator substrate; the width of the drive coil is smaller than the width of the inductor coil.

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