Reciprocating optical wobble mirror motor

Abstract

The application relates to a reciprocating optical swing mirror motor, which comprises a stator base, a stator fixed opposite to the stator base and a coil winding, and further comprises a rotor and a mirror assembly fixed opposite to each other, the mirror assembly comprises a mirror frame and a mirror arranged on the outer surface of the mirror frame, a cavity is arranged in the mirror frame, a rotating shaft penetrates through the cavity and the top end of the rotating shaft is fixed opposite to the mirror frame, the mirror frame is buckled on the stator base, and the rotating shaft is rotatably arranged on the stator through a bearing; the coil winding is a tooth-groove-free hollow cup coil winding and is arranged between the stator and the rotor. The coil winding of the reciprocating optical swing mirror motor is composed of a tooth-groove-free hollow cup coil, the motor is directly driven to rotate through electromagnetic force, a closed loop force control mode is supported, the response time is fast, the magnetic resistance torque is eliminated through the non-iron core design, the low-speed movement is smooth (without shaking), and the positioning precision and the repeatability are improved.

Description

Technical Field

[0001] This application relates to the field of beam reflection control scanning technology, and in particular to a reciprocating optical oscillating mirror motor. Background Technology

[0002] In beam reflection control scanning applications (such as laser processing and optical inspection systems), beam deflection is typically achieved using slender galvanometer motors or rotary mirror motors. Rotary mirror motors generally employ a three-phase brushless motor with an external rotor structure. The stator is constructed from a slotted silicon steel core wound with enameled wire, and the rotor uses a cylindrical toroidal permanent magnet. This type of structure has the following inherent drawbacks:

[0003] (1) Cogging torque: The interaction between the stator cogging and the permanent magnet generates periodic torque fluctuations, resulting in uneven torque output when the motor is running at low speed.

[0004] (2) Commutation torque pulsation: When using three-phase six-state electronic commutation (square wave / sine wave control), the switching process of the power transistors that are turned on in pairs causes the current to be discontinuous, resulting in significant torque pulsation, which causes the output torque of the motor to be unstable during reciprocating motion.

[0005] (3) Control complexity and accuracy limitations: To suppress torque pulsation, complex control strategies (such as field-oriented control (FOC) or sinusoidal wave drive) need to be introduced. However, such algorithms have a lag in response at low speeds and high frequency commutation, resulting in decreased control accuracy and difficulty in meeting the requirements of high dynamic scanning.

[0006] (4) Insufficient dynamic performance: The motor rotor has a large inertia, and the acceleration and deceleration response is slow in frequent reciprocating motion, making it difficult to achieve high-speed and high-frequency start-stop switching, which restricts scanning efficiency.

[0007] (5) Mechanical loss and positioning error: The backlash and friction loss in the transmission chain further reduce the positioning accuracy and motion repeatability of the system, affecting the beam pointing stability. Utility Model Content

[0008] To address the technical problems existing in the prior art, this application proposes a reciprocating optical oscillating mirror motor. The coil winding of the optical oscillating mirror motor is composed of a slotless hollow cup coil. The motor is directly driven to rotate by electromagnetic force. The force and current have a linear relationship, supporting closed-loop force control mode. It has a fast response time, and the coreless design eliminates magnetic reluctance torque. The low-speed movement is smooth (without jitter), which improves positioning accuracy and repeatability.

[0009] This application proposes a reciprocating optical oscillating mirror motor, including a stator base, a stator and coil windings fixed relative to it, and a rotor and a mirror assembly fixed relative to each other. The mirror assembly includes a mirror frame and a mirror disposed on its outer surface. The mirror frame has a cavity inside, and a rotating shaft passes through the cavity with its top end fixed relative to the mirror frame. The mirror frame is fastened to the stator base, and the rotating shaft is rotatably disposed with respect to the stator via a bearing. The coil winding is a slotless hollow cup coil winding and is disposed between the stator and the rotor.

[0010] Optionally, the coil winding is a single-phase coil, and the number of petals of the coil winding is equal to the number of magnetic poles of the rotor.

[0011] Optionally, the rotor is a two-pole combination, and the coil winding is a two-lobed structure, including a first lobe coil and a second lobe coil arranged symmetrically with respect to the rotating axis.

[0012] Optionally, the first lobe coil and / or the second lobe coil includes two C-shaped portions arranged around the outside of the magnet and square pillars connecting the ends of the two C-shaped portions respectively.

[0013] Optionally, the windings constituting the coil winding are externally wrapped with an insulator.

[0014] Optionally, it includes an angle detection unit, which consists of a magnet and an encoder chip. The encoder chip is disposed below the magnet. The encoder chip uses the magnetoresistive effect to detect the change in the direction of the magnetic field parallel to the chip surface of the rotor, and outputs the corresponding angle value accordingly. The encoder chip is disposed in the PCB board on the stator base.

[0015] Optionally, the rotor is sleeved outside the stator and fixedly connected to the inner wall of the mirror frame, and a slot is opened at the end of the rotating shaft, with the magnet disposed in the slot.

[0016] Optionally, the bearing includes a first bearing and a second bearing, with a step provided between the first bearing and the second bearing. The frame has an opening for the rotating shaft to pass through, and the edge of the opening is provided with a protruding ridge. The protruding ridge located inside the frame is used to abut against the first bearing adjacent to it.

[0017] Optionally, the rotor is sleeved on the lower part of the rotating shaft, close to the stator base, the coil winding is fixed to the inner wall of the stator, and the rotor is the magnet of the angle detection unit.

[0018] Optionally, the height of the coil winding is adapted to the height of the rotor.

[0019] The reciprocating optical oscillating mirror motor proposed in this embodiment employs a slotless hollow cup coil design for its coil windings. The motor rotation is directly driven by electromagnetic force, with a linear relationship between force and current (F=BIL), supporting closed-loop force control mode and exhibiting fast response time. Furthermore, the coil windings in this embodiment are single-phase coils, allowing operation immediately upon energization. This eliminates the complex commutation circuit and control strategy required by three-phase brushless motors, simplifying the control system and reducing costs. Moreover, the coreless design eliminates reluctance torque, resulting in smooth low-speed motion (without jitter) and improved positioning accuracy and repeatability. Attached Figure Description

[0020] The preferred embodiments of this application will now be described in further detail with reference to the accompanying drawings, wherein:

[0021] Figure 1 This is a three-dimensional structural schematic diagram of a reciprocating optical oscillating reflector motor according to an embodiment of this application;

[0022] Figure 2 External structure such as Figure 1 A sectional view along line AA of one embodiment is shown;

[0023] Figure 3 External structure such as Figure 1 A sectional view along line AA of another embodiment is shown;

[0024] Figure 4 This is a three-dimensional structural diagram of a coil winding according to an embodiment of this application;

[0025] Figure 5 This is a three-dimensional structural diagram of another coil winding according to an embodiment of this application;

[0026] Figure 6 yes Figure 4 A schematic diagram of the coil winding structure shown.

[0027] Figure 7 yes Figure 5 The diagram shows the coil winding structure of the coil shown.

[0028] Explanation of reference numerals in the attached figures:

[0029] 100. Optical oscillating mirror motor with compound motion; 101. Includes mirror assembly; 102. Stator; 103. Rotor; 104. Coil winding; 105. Angle detection unit; 106. Stator base; 107. PCB board; 108. Bearing; 109. Shaft; 1011. Mirror frame; 1012. Mirror; 1041. Enamelled wire; 1051. Magnet; 1013. Opening; 101 4. Raised ridge; 1042. First lobe coil; 1043. Second lobe coil; 1041. Coil; 1041. Enamelled wire; 1141 and 1241. Two enamelled wires in the coil winding; 1052. Encoder chip; 1044. C-shaped section; 1045. Square prism; 1081. First bearing; 1082. Second bearing; 1091. Slot; 201. Step; 1046. Insulator. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In the following detailed description, reference can be made to the accompanying drawings, which form part of this application and illustrate specific embodiments of the present application. In the drawings, similar reference numerals describe substantially similar components in different figures. Specific embodiments of the present application are described in sufficient detail below to enable those skilled in the art to implement the technical solutions of the present application. It should be understood that other embodiments may also be utilized, or structural, logical, or electrical changes may be made to the embodiments of the present application.

[0032] Figure 1 This is a three-dimensional structural diagram of a reciprocating optical oscillating reflector motor according to an embodiment of this application. Figure 2 External structure such as Figure 1 A sectional view along line AA of one embodiment is shown. Combined with... Figure 1 and Figure 2As shown, the reciprocating optical oscillating mirror motor 100 includes a stator base 106, a stator 102 fixed to it, and a coil winding 104. It also includes a rotor 103 and a mirror assembly fixed to each other. The mirror assembly includes a mirror frame 1011 and a mirror 1012 disposed on its outer surface. The mirror frame 1011 has a cavity inside, and a rotating shaft 109 passes through the cavity with its top end fixed to the mirror frame 1011. The mirror frame 1011 is fastened to the stator base 106, and the rotating shaft 109 is rotatably mounted to the stator 102 via a bearing 108. The coil winding 104 is a slotless hollow cup coil winding, disposed between the stator 102 and the rotor 103. The stator 102 is made of a soft magnetic material, such as pure iron, iron-nickel alloy, low-carbon steel, or magnetically conductive stainless steel, while the rotor 103 is made of a magnetic material, such as ferrite or neodymium iron boron.

[0033] In some embodiments of this application, optionally, one or more reflective mirrors 1012 are attached to the frame 1011 to reflect an external laser source in order to control the laser beam. The frame 1011 is hollow and is provided with a stator 102, a rotor 103, a rotating shaft 109 partially disposed inside the frame 1011, and a bearing 108. The stator 102 is sleeved on the outer ring of the bearing 108, the inner ring of the bearing 108 is sleeved on the upper part of the rotating shaft 109, the rotor 103 is sleeved on the lower part of the rotating shaft 109 and close to the stator base 106, and a coil winding 104 is disposed between the stator 102 and the rotor 103. The coil winding 104 is a slotless hollow cup coil winding, and the coil in the coil winding 104 is a single-phase coil. In this embodiment, since the rotor 103 is sleeved on the lower part of the rotating shaft 109 and the coil winding 104 is fixed on the inner wall of the stator 102, after the reciprocating optical oscillating mirror motor 100 is energized, the rotor 103 drives the rotating shaft to rotate, and the rotating shaft drives the mirror frame to rotate. Therefore, in this embodiment, the reciprocating optical oscillating mirror motor 100 is an inner rotor motor.

[0034] In some embodiments of this application, the reciprocating optical oscillating mirror motor 100 is an external rotor motor. Figure 3 External structure such as Figure 1 A cross-sectional view along line AA of another embodiment is shown. Combined with... Figure 1 and Figure 3 As shown, in this embodiment, the rotor 103 of the reciprocating optical oscillating mirror motor 100 is disposed on the inner wall of the mirror frame 1011 and sleeved on the outside of the stator 102. A coil winding is sleeved on the outer wall of the stator, and there is a gap between the coil winding and the rotor 103. In this embodiment, after the reciprocating optical oscillating mirror motor 100 is energized, the rotor 103 drives the mirror frame to rotate around the axis. Therefore, in this embodiment, the reciprocating optical oscillating mirror motor 100 is an external rotor motor.

[0035] Furthermore, regardless of Figure 2 The internal rotor electronics in the embodiment are still Figure 3 The external rotor motors in the embodiments all operate on the following principle: the excitation source supplies current, directly driving the rotor to rotate. Changing the current frequency, magnitude, and direction controls the rotor's forward and reverse rotation, angular velocity, and angular travel. For example, supplying a sinusoidal current with a certain amplitude and frequency to the excitation source can produce a perfect sinusoidal flux linkage waveform, a sinusoidal electromagnetic torque waveform, and a sinusoidal back electromotive force waveform. Furthermore, in the reciprocating optical oscillating mirror motor 100 of this application, whether it is an internal rotor motor or an external rotor motor, the coil windings have abandoned the previous method of winding on the stator slots, and instead selected slotless hollow cup coil windings. The use of slotless hollow cup coil windings enables the reciprocating optical oscillating mirror motor 100 of this application to support closed-loop force control mode and has a fast response time. The coreless design eliminates magnetic reluctance torque, resulting in smooth low-speed movement (without jitter), improving positioning accuracy and repeatability.

[0036] See also Figure 2 or Figure 3 As shown, the reciprocating optical oscillating reflector motor also includes an angle detection unit 105 and a PCB board 107. The angle detection unit is used to detect the rotation angle of the shaft 109. The PCB board 107 and the stator 102 are fixed on the stator base 106. The angle detection unit 105 includes a magnet 1051 and an encoder chip 1052. The encoder chip 1052 is one of the electrical components of the angle detection unit and is located below the magnet 1051. The encoder chip 1052 uses the magnetoresistance effect to detect the change in the direction of the magnetic field parallel to the chip surface of the rotor, and outputs the corresponding angle value accordingly.

[0037] In this embodiment, the encoder chip 1052 can be an angle sensor chip based on advanced AMR magnetoresistive technology and advanced signal processing technology. It can sense changes in the direction of a magnetic field parallel to the chip surface and output the corresponding angle value. AMR (Anisotropic Magnetoresistance) is a sensing technology based on the magnetoresistive effect. Its core principle is that the resistance of a material changes with the angle between the direction of the applied magnetic field and the direction of the current. When the external magnetic field forms a certain angle with the direction of the material's built-in magnetic field, the magnetization vector shifts, causing the resistance to decrease and forming a linear response region. A typical material is permalloy (nickel-iron alloy), which has the characteristics of high sensitivity and stability. AMR utilizes the anisotropic magnetoresistive effect, and the sensor sensitivity is significantly higher than that of Hall elements. It also has a wider magnetic field detection range, a wider magnetic field detection range, and higher reliability. Optionally, in some embodiments of this application, the AMR magnetoresistive sensor made based on AMR magnetoresistive technology in the encoder chip 1052 supports 3 channels and 21-bit high resolution.

[0038] Alternatively, in this embodiment, the encoder chip 1052 can also be an angle sensor chip based on the tunneling magnetoresistive effect and advanced signal processing technology. The TMR tunneling magnetoresistive sensor in the encoder chip 1052, made based on the tunneling magnetoresistive effect, has high sensitivity. The structure of the TMR tunneling magnetoresistive sensor is more complex, typically consisting of two strongly magnetic layers sandwiching a very thin insulating layer. This structure allows the TMR tunneling magnetoresistive sensor to produce significant resistance changes under extremely small magnetic field variations. Therefore, the TMR tunneling magnetoresistive sensor has extremely high sensitivity and resolution, can operate under extremely low magnetic fields, and has extremely high stability. Depending on the application scenario, the angle detection unit can also employ photoelectric encoders, photodiodes, eddy current generators, rotary transformers, magnetic encoders, capacitive sensors, etc.

[0039] Figure 4 This is a three-dimensional structural diagram of a coil winding according to an embodiment of this application. Figure 5 This is a three-dimensional structural schematic diagram of another coil winding according to an embodiment of this application. (Combined with...) Figures 2-5 As shown, the number of lobes in the coil winding 104 is equal to the number of magnetic poles in the rotor 103. Specifically, the rotor 103 is a two-pole combination, and the coil winding 104 has a two-lobed structure, including a first-lobed coil 1042 and a second-lobed coil 1043 with symmetrical structures. The first-lobed coil 1042 and / or the second-lobed coil 1043 of the coil winding 104 include two C-shaped portions 1044 arranged around the outside of the magnet and square prisms 1045 connecting the ends of the two C-shaped portions respectively.

[0040] in, Figure 4 and Figure 5 The difference in the coil windings in the embodiments is that, Figure 4 In the embodiment, the coil in the coil winding is wound with a single enameled wire 1041, combined with Figure 6 As shown, a single enameled wire includes two leads, "Right 1" and "Left n," and the first coil 1042 and the second coil 1043 are connected in series. Figure 5 In the embodiment, the coil in the coil winding is made of two enameled wires 1141 and 1241, combined with Figure 7 As shown, the enameled wire includes four leads: "Right 1", "Left 1", "Right n", and "Left n". The first lobe coil 1042 and the second lobe coil 1043 are connected in parallel. The single-phase coil can operate simply by being energized, eliminating the complex commutation circuit and control strategy required by a three-phase brushless motor, simplifying the control system and reducing costs.

[0041] In some embodiments of this application, optionally, the windings constituting the winding in the coil winding 104 are wrapped with an insulator 1046. The insulator 1046 may also be referred to as an insulating unit or insulating element. The coils in the coil winding 104 are typically encapsulated in a gel, which serves to connect to the stator and provide insulation.

[0042] In some embodiments of this application, optionally, the height of the coil winding 104 is adapted to the height of the rotor 103. This allows the rotor to rotate more smoothly.

[0043] See also Figure 3 As shown, with the rotor 103 sleeved outside the stator 102 and fixedly connected to the inner wall of the mirror frame 1011, the bearing 108 includes a first bearing 1081 and a second bearing 1082. A step 201 is provided between the first bearing 1081 and the second bearing 1082. The mirror frame 1011 has an opening 1013 for the shaft 109 to pass through. The edge of the opening 1013 is provided with a protruding rib 1014. The protruding rib 1014 located inside the mirror frame 1011 is used to abut against the adjacent first bearing 1081. Providing the step 201 between the first bearing 1081 and the second bearing 1082 can restrict the axial movement of the bearing and ensure its accurate position on the shaft.

[0044] In addition, Figure 3 In the illustrated embodiment, when the rotor 103 is sleeved outside the stator 102 and fixedly connected to the inner wall of the mirror frame 1011, the magnet 1051 is disposed in a slot 1091 opened at the end of the rotating shaft 109, and this magnet 1051 is the magnet of the angle detection unit. However, in Figure 2 In the embodiment shown, the rotor 103 is sleeved on the lower part of the rotating shaft 109, close to the stator base 106, and the rotor 103 is the magnet of the angle detection unit.

[0045] In summary, the reciprocating optical oscillating mirror motor proposed in this application adopts a slotless hollow cup coil design, directly driving the motor rotation through electromagnetic force. The force and current have a linear relationship (F=BIL), supporting closed-loop force control mode and exhibiting fast response time. Single-phase coils can operate upon energization, eliminating the complex commutation circuit and control strategy of three-phase brushless motors, simplifying the control system and reducing costs. The coreless design eliminates reluctance torque, resulting in smooth low-speed motion (without jitter), improving positioning accuracy and repeatability.

[0046] The above embodiments are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art can make various changes and modifications without departing from the scope of this application. Therefore, all equivalent technical solutions should also fall within the scope of this application.

Claims

1. A reciprocating optical oscillating mirror motor, comprising a stator base, a stator and coil windings fixed thereto, and a rotor and a mirror assembly fixed to each other, the mirror assembly comprising a frame and a mirror disposed on its outer surface, characterized in that, The frame has a cavity inside, the rotating shaft passes through the cavity and the top end of the rotating shaft is fixed relative to the frame, the frame is fastened to the stator base, and the rotating shaft is rotatably connected to the stator through a bearing; The coil winding is a slotless hollow cup coil winding, which is disposed between the stator and the rotor.

2. The reciprocating optical oscillating mirror motor according to claim 1, characterized in that, The coil winding is a single-phase coil, and the number of lobes in the coil winding is equal to the number of magnetic poles of the rotor.

3. The reciprocating optical oscillating mirror motor according to claim 1, characterized in that, The rotor is a combination of two magnetic poles, and the coil winding has a two-lobed structure, including a first lobe coil and a second lobe coil arranged symmetrically with respect to the rotating shaft.

4. The reciprocating optical oscillating mirror motor according to claim 3, characterized in that, The first lobe coil and / or the second lobe coil include two C-shaped portions arranged around the outside of the magnet and square pillars connecting the ends of the two C-shaped portions respectively.

5. The reciprocating optical oscillating mirror motor according to claim 2, characterized in that, The coil windings are wrapped with an insulator.

6. The reciprocating optical oscillating mirror motor according to claim 1, characterized in that, It includes an angle detection unit, which consists of a magnet and an encoder chip. The encoder chip is located below the magnet. The encoder chip uses the magnetoresistive effect to detect the change in the direction of the magnetic field parallel to the chip surface of the rotor, and outputs the corresponding angle value accordingly. The encoder chip is located inside the PCB board on the stator base.

7. The reciprocating optical oscillating mirror motor according to claim 6, characterized in that, The rotor is sleeved on the outside of the stator and fixedly connected to the inner wall of the mirror frame. The end of the rotating shaft is provided with a slot, and the magnet is disposed in the slot.

8. The reciprocating optical oscillating mirror motor according to claim 7, characterized in that, The bearing includes a first bearing and a second bearing, with a step between the first bearing and the second bearing. The frame has an opening for the rotating shaft to pass through, and the edge of the opening has a protruding ridge. The protruding ridge located inside the frame is used to abut against the first bearing adjacent to it.

9. The reciprocating optical oscillating mirror motor according to claim 6, characterized in that, The rotor is sleeved on the lower part of the rotating shaft, close to the stator base, the coil winding is fixed on the inner wall of the stator, and the rotor is the magnet of the angle detection unit.

10. The reciprocating optical oscillating mirror motor according to claim 1, characterized in that, The height of the coil winding is adapted to the height of the rotor.

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