CN117200505B - Galvanometer motor - Google Patents

Abstract

The present invention relates to the technical field of motors, and provides a galvanometer motor, including a stator, a rotor and a sensor plate, wherein the rotor includes a rotating shaft and a galvanometer lens, the middle part of the rotating shaft is a pair of radially magnetized magnetic poles, the two ends of the rotating shaft are rotatably mounted in a housing, and the sensor plate is equipped with a magnetic sensor. The beneficial effect of the galvanometer motor provided by the present invention is that the middle part of the rotating shaft is a pair of radially magnetized magnetic poles, which can not only rotate in the rotating magnetic field generated by the driving coil, but also can be directly sensed by the magnetic sensor to obtain the absolute position of the rotating shaft by its magnetic field signal, and the rotating shaft does not need to be additionally installed with a feedback sensor, and correspondingly, the volume of the galvanometer motor is reduced, solving the technical problem of the excessive volume of the galvanometer motor in the related art, thereby reducing the difficulty of installing the galvanometer motor and improving the yield rate of the galvanometer motor.

Description

Galvanometer motor

Technical Field

The present invention relates to the technical field of motors, and in particular to a galvanometer motor.

Background Art

Galvanometer motors are mainly used in laser equipment such as laser radar, laser marking machines, laser engraving machines, etc. Under the control of a dedicated controller, the shaft of the galvanometer motor drives the galvanometer to swing, so that the reflected laser reaches a specific position accurately.

In the related art, the stator of the galvanometer motor is a coil, and the rotor is a magnet. The rotor is located inside the stator. The coil drives the rotor to reciprocate under the action of the alternating drive current. In order to achieve precise positioning performance, the tail of the motor is provided with a chamber specifically for installing feedback sensors such as encoders. However, the installation of the feedback sensor lengthens the tail of the motor, increases the size of the galvanometer motor, and increases the number of parts of the galvanometer motor, making the structure complex and the yield rate low.

Summary of the invention

The object of the present invention is to provide a galvanometer motor, aiming to solve the technical problem of the galvanometer motor being too large in size in the related art.

The present application provides a galvanometer motor, comprising:

A stator, the stator comprising a housing and a driving coil installed in the housing;

A rotor, the rotor comprising a rotating shaft and a galvanometer lens, the middle portion of the rotating shaft is a pair of radially magnetized magnetic poles, both ends of the rotating shaft are rotatably mounted in the housing, and one end of the rotating shaft extends to the outside of the housing and is connected to the galvanometer lens;

A sensor board is fixed to the inner wall of the shell and is located at an end of the shell away from the galvanometer lens. The sensor board is equipped with a magnetic sensor, which is used to sense the magnetic field signal generated by a pair of magnetic poles to obtain the absolute position of the rotating shaft and the galvanometer lens.

In one embodiment, the driving coil is wound to form an air-core winding.

In one embodiment, the shell is installed with a first limit member, and the rotating shaft is connected with a second limit member. The first limit member and the second limit member cooperate with each other to allow the rotating shaft to rotate between a first extreme position and a second extreme position, and the central angle formed by the first extreme position and the second extreme position and the axis of the rotating shaft is less than 90°.

In one embodiment, the output signal of the magnetic sensor is in a sinusoidal function relationship with the angle of the rotating shaft, and the angle of the rotating shaft between the first extreme position and the second extreme position corresponds to a monotonic interval of the sinusoidal function relationship.

In one embodiment, the first limiting member is located on an outer wall of one end of the shell close to the galvanometer lens, the number of the first limiting members is two, the two first limiting members are arranged opposite to each other, and the second limiting member corresponds to the first limiting member one by one.

In one embodiment, the first limit member is two limit blocks arranged at one end of the shell near the galvanometer lens, and the two limit blocks are arranged at intervals so that the second limit member contacts one of the limit blocks when the rotating shaft rotates to the first extreme position, and the second limit member contacts the other limit block when the rotating shaft rotates to the second extreme position.

In one embodiment, the number of the magnetic sensors is more than two, and the phase difference between any two of the magnetic sensors is greater than 0° and less than 180°.

In one embodiment, the magnetic sensor includes a differential Hall sensor group, and the differential Hall sensor group includes two differential Hall sensing units, and the phase difference between the two differential Hall sensing units is 180°.

In one embodiment, the shell includes a shell body and a tail cover, one end of the shell body is open, the tail cover is detachably mounted on the open end of the shell body, the sensor board is fixed to the inner side of the tail cover, and one end of the rotating shaft is rotatably mounted on the tail cover.

In one of the embodiments, the tail cover has a wire outlet hole, and the wiring terminals of the drive coil and the leads of the sensor board are electrically connected to the external drive board through the wire outlet hole.

In one embodiment, the galvanometer motor further includes two bearings, which are mounted at both ends of the housing and sleeved on the rotating shaft, and the drive coil, the magnetic pole, the sensor plate and the magnetic sensor are located between the two bearings.

The beneficial effects of the galvanometer motor provided by the present invention are as follows: the driving coil is connected to an alternating current to drive a pair of magnetic poles to rotate, that is, the rotating shaft and the galvanometer lens rotate; the rotation of the pair of magnetic poles will change the magnetic field signals generated by them, and the magnetic sensor obtains the absolute position of the rotating shaft by sensing the magnetic field signals, and then obtains the absolute position of the galvanometer lens connected to the rotating shaft; the middle part of the rotating shaft is a pair of radially magnetized magnetic poles, and compared with multiple pairs of magnets arranged in an interlaced manner, the number of parts is reduced, and it can rotate in the rotating magnetic field generated by the driving coil, and can also be directly sensed by the magnetic sensor for its magnetic field signal to obtain the absolute position of the rotating shaft. The rotating shaft does not need to be additionally installed with a feedback sensor. Correspondingly, the size of the galvanometer motor is reduced, solving the technical problem of the excessive size of the galvanometer motor in the related art, thereby reducing the difficulty of installing the galvanometer motor and improving the yield of the galvanometer motor.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

FIG1 is a schematic structural diagram of a galvanometer motor provided in an embodiment of the present invention;

FIG2 is an exploded view of the galvanometer motor in FIG1 ;

Fig. 3 is a cross-sectional view of the galvanometer motor in Fig. 1 along line A-A;

FIG4 is a schematic diagram of the installation of the rotating shaft and the sensor plate of the galvanometer motor provided in the embodiment;

FIG5 is a schematic diagram of the structure of the sensor board in FIG4 ;

FIG6 is a graph of an output signal of a magnetic sensor of a galvanometer motor provided in an embodiment;

FIG7 is a schematic diagram of the installation of the rotating shaft and the sensor plate of the galvanometer motor provided by another embodiment;

FIG8 is a graph showing an output signal of a magnetic sensor of the galvanometer motor in FIG7 ;

FIG9 is a schematic diagram of the installation of a rotating shaft and a sensor plate of a galvanometer motor provided by yet another embodiment;

FIG. 10 is a graph showing an output signal of a magnetic sensor of the galvanometer motor in FIG. 9 .

Among them, the reference numerals in the figure are:

100, stator; 110, housing; 111, first limiting member; 112, limiting block; 113, limiting groove; 114, connecting wall; 115, housing body; 116, tail cover; 117, outlet hole; 120, driving coil; 121, terminal;

200, rotor; 210, rotating shaft; 211, magnetic pole; 212, second stopper; 220, galvanometer lens;

300, sensor board; 310, magnetic sensor; 311, differential Hall sensor group; 312, differential Hall sensor unit; 320, lead wire;

400. Bearings.

DETAILED DESCRIPTION

Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

Reference throughout the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, when the phrases "in one embodiment" or "in some embodiments" appear in various places throughout the specification, not all references are to the same embodiment. Furthermore, in one or more embodiments, the particular features, structures, or characteristics may be combined in any suitable manner.

In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

The galvanometer motor in the embodiment of the present invention is now described.

Please refer to FIG. 1 to FIG. 3 , the galvanometer motor provided in this embodiment includes a stator 100 , a rotor 200 and a sensor plate 300 .

The stator 100 includes a housing 110 and a driving coil 120 installed in the housing 110. Optionally, the number of the terminals 121 of the driving coil 120 is two. The rotor 200 includes a rotating shaft 210 and a galvanometer lens 220. The middle part of the rotating shaft 210 is a pair of radially magnetized magnetic poles 211, and the two ends of the rotating shaft 210 are rotatably installed in the housing 110. One end of the rotating shaft 210 extends to the outside of the housing 110 and is connected to the galvanometer lens 220. There is a gap between the stator 100 and the rotor 200. The sensor board 300 is fixed to the inner wall of the housing 110 and is located at one end of the housing 110 away from the galvanometer lens 220. The sensor board 300 is installed with a magnetic sensor 310, which is used to sense the magnetic field signal generated by the pair of magnetic poles 211 to obtain the absolute position of the rotating shaft 210 and the galvanometer lens 220.

In a specific embodiment of the present application, the driving coil 120 has only two terminals 121 connected to the alternating current. It only needs to input the alternating current as the control signal in one direction, and the driving coil 120 generates a rotating magnetic field, driving a pair of magnetic poles 211 to rotate, that is, the rotating shaft 210 and the galvanometer lens 220 rotate. The rotation of the pair of magnetic poles 211 will change the magnetic field signal generated by them. The magnetic sensor 310 obtains the absolute position of the rotating shaft 210 by sensing the magnetic field signal, and then obtains the absolute position of the galvanometer lens 220 connected to the rotating shaft 210. The middle part of the rotating shaft 210 is a pair of radially magnetized magnetic poles 211. Compared with multiple pairs of magnets arranged in an interlaced manner, the number of parts is reduced. It can rotate in the rotating magnetic field generated by the driving coil 120, and can also be directly sensed by the magnetic sensor 310 to obtain the absolute position of the rotating shaft 210. The rotating shaft 210 does not need to be additionally installed with a feedback sensor, and the structure is compact, which is conducive to reducing the difficulty of installing the galvanometer motor, reducing the volume of the galvanometer motor, and improving the yield rate of the galvanometer motor.

In another specific embodiment of the present application, the drive coil 120 is wound to form a hollow winding. There is no iron core inside the drive coil 120, which has the characteristics of small inductance and small back electromotive force, so that the control signal changes more quickly and the response speed is improved.

In another specific embodiment of the present application, please refer to FIG. 2 , the housing 110 is installed with a first stopper 111, the rotating shaft 210 is connected with a second stopper 212, the first stopper 111 and the second stopper 212 are limited and matched, so that the rotating shaft 210 rotates between the first limit position and the second limit position, and the center angle formed by the first limit position and the second limit position and the axis of the rotating shaft 210 is less than 90°. In other words, the angle of rotation of the rotating shaft 210 from the first limit position to the second limit position around its own axis is the center angle.

On the premise of meeting the rotation requirements of the laser radar product for the galvanometer lens 220, the galvanometer motor limits the rotation angle of the galvanometer lens 220 to within 90°, which is conducive to quickly determining the rotation angle of the rotating shaft 210 relative to the initial position within a limited rotation angle according to the output signal of the magnetic sensor 310, and then determining the absolute position of the rotating shaft 210 and the galvanometer lens 220.

Optionally, a central angle formed by the first extreme position, the second extreme position and the axis of the rotating shaft 210 is 5°, 10°, 20°, 30°, 45° or 60°.

Please refer to Figures 3 and 6. The output signal of the magnetic sensor 310 and the angle of the shaft 210 are in a sinusoidal function relationship. When the shaft 210 rotates one circle, the magnetic sensor 310 will generate a complete sine wave. The sinusoidal function relationship in this application refers to the output signal y of the magnetic sensor 310 and the angle x of the shaft 210 satisfying the sinusoidal function analytical expression: Among them, the parameters A, ω, and h depend on the specific scenario.

In some embodiments, the angle of the rotating shaft 210 between the first extreme position and the second extreme position corresponds to the monotonic interval of the sine function relationship. In other words, the output signal y of the magnetic sensor 310 corresponds to the angle x of the rotating shaft 210 one by one, so that the angle x of the rotating shaft 210 obtained according to the output signal y of the magnetic sensor 310 is a unique value. For example, referring to FIG6 , the dotted box is located in the monotonic interval of curve B, but not in the monotonic interval of curve A.

The output signal of the magnetic sensor 310 is generally a voltage.

The staff can define the positional relationship between the magnetic sensor 310 and the magnetic pole 211 during production, thereby ensuring that the angle of the rotating shaft 210 between the first extreme position and the second extreme position corresponds to a monotonic interval of a sinusoidal function relationship.

Specifically, please refer to FIG7 . When the rotating shaft 210 is in the initial position, the magnetic sensor 310 is mounted on the sensor plate 300 , and the junction of the magnetic sensor 310 and the pair of magnetic poles 211 is located in the same radial direction of the rotating shaft 210 . In other words, the rotation angle of the rotating shaft 210 is 0, and the magnetic sensor 310 and the junction of the pair of magnetic poles 211 are arranged opposite to each other. As shown in FIG8 , since the magnetic field intensity at the junction of the pair of magnetic poles 211 is the smallest, the output signal of the magnetic sensor 310 is the average value of the sine wave (see point C in FIG8 ). The rotating shaft 210 rotates within ±45°, and is located in the monotonic interval of the sine function relationship, so that the output signal of the magnetic sensor 310 and the angle of the rotating shaft 210 correspond one to one. In this way, during production and manufacturing, by limiting the relative position relationship between the magnetic sensor 310 and the pair of magnetic poles 211 at the initial position, the angle of the rotating shaft 210 between the first extreme position and the second extreme position corresponds to the monotonic interval of the sine function relationship.

It can be understood that, since the rotation angle of the rotating shaft 210 is less than 90°, in other examples, it is only necessary to ensure that the rotating shaft 210 falls into the monotonic interval of the sine function relationship when rotating within the rotation angle range. When the rotating shaft 210 is in the initial position, the intersection of the magnetic sensor 310 and the pair of magnetic poles 211 is not necessarily required to be located in the same radial direction of the rotating shaft 210. For example, the rotation angle of the rotating shaft 210 is ±π/6, and when the rotation angle of the rotating shaft 210 is 0, the center angle formed between the intersection of the magnetic sensor 310 and the pair of magnetic poles 211 is within ±π/3. Referring to FIG8, when the rotating shaft 210 is in the initial position, the horizontal coordinate is located in the interval D. The interval D moves left and right by π/6, and still corresponds to the monotonic interval of the sine function relationship, that is, the output signal of the magnetic sensor 310 and the angle of the rotating shaft 210 correspond one to one.

Specifically, please refer to FIG9 . When the rotating shaft 210 is at the first extreme position or the second extreme position, the magnetic sensor 310 is mounted on the sensor plate 300, and the central angle formed by the intersection of the magnetic sensor 310 and the pair of magnetic poles 211 is 90°. In other words, the magnetic sensor 310 is arranged relative to the point where one of the magnetic poles 211 is farthest from the other magnetic pole 211. Please refer to FIG10 . When the central angle formed by the intersection of the magnetic sensor 310 and the pair of magnetic poles 211 is 90°, the output signal of the magnetic sensor 310 is a peak value E or a peak value F. The rotating shaft 210 rotates 90° along a certain rotation direction, that is, the horizontal coordinate of the peak value E or the peak value F in FIG10 is shifted to the left by π/2 or to the right by π/2, and is still located within the monotonic interval of the sine function relationship, so that the output signal of the magnetic sensor 310 corresponds to the angle of the rotating shaft 210 one by one.

It can be understood that in other examples, since the rotation angle of the shaft 210 is less than 90°, when the shaft 210 is in the first extreme position or the second extreme position, the junction between the magnetic sensor 310 and a pair of magnetic poles 211 does not necessarily form a central angle of 90°. It is only necessary to ensure that the shaft 210 falls into the monotonic interval of the sinusoidal function relationship when rotating within a limited angle.

In some embodiments, please refer to FIG5 , the number of magnetic sensors 310 is more than two, and the phase difference between any two magnetic sensors 310 is greater than 0° and less than 180°. At this time, the output signal of each magnetic sensor 310 and the angle of the shaft 210 are in a sinusoidal function relationship, and two sinusoidal curves (see curve A and curve B in FIG6 ) are obtained by more than two magnetic sensors 310, which has a backup effect of mutual correction, and can uniquely determine the rotation angle of the shaft 210, and then obtain the absolute position of the shaft 210 and the galvanometer lens 220. It is not necessary to require that the angle of the shaft 210 between the first extreme position and the second extreme position corresponds to the monotonic interval of the sinusoidal function relationship, that is, it is not necessary to consider the relative position between the magnetic sensor 310 and the magnetic pole 211 during installation, which further reduces the difficulty of installation and improves the yield rate.

Generally, the number of magnetic sensors 310 is two or three. For example, referring to FIG6 , the number of magnetic sensors 310 is two. The two magnetic sensors 310 can be installed at any position on the sensor board 300, and can uniquely determine the angle of the rotating shaft 210, meeting the requirement of measuring the absolute position of the galvanometer lens 220. Therefore, by using as few magnetic sensors 310 as possible, the number of parts of the galvanometer motor can be reduced, and the difficulty and cost of installing the galvanometer motor can be reduced.

In another specific embodiment of the present application, the magnetic sensor 310 is a Hall sensor, an MR (Magneto Resistance) sensor, or an MI (Magneto Impedance) sensor.

Specifically, referring to FIG. 5 , the magnetic sensor 310 includes a differential Hall sensor group 311. The differential Hall sensor group 311 includes two differential Hall sensing units 312, and the phase difference between the two differential Hall sensing units 312 is 180°. The two differential Hall sensing units 312 of the differential Hall sensor group 311 are relatively arranged on the sensor board 300 to form a differential signal, thereby preventing one of the differential Hall sensing units 312 from being interfered by the environmental magnetic field, improving the anti-interference ability of the signal, improving the accuracy of the magnetic sensor 310, and improving the reliability of the galvanometer motor.

In this embodiment, a pair of radially magnetized magnetic poles 211 are cylindrical, one of the magnetic poles 211 is an S pole, and the other magnetic pole 211 is an N pole. The magnetic poles 211 are permanent magnets.

In this embodiment, referring to Figures 1 and 2, the first stopper 111 is located on the outer wall of the housing 110 at one end close to the galvanometer lens 220. The first stopper 111 is disposed on the outer wall of the housing 110, so that the first stopper 111 and the second stopper 212 can form a stopper match during production, thereby reducing the difficulty of installation and improving the yield rate.

The galvanometer lens 220 is driven to rotate by the rotating shaft 210. The galvanometer lens 220 belongs to the rotor 200, and the housing 110 belongs to the stator 100. There is a gap between the two to prevent the galvanometer lens 220 from rubbing against the stator 100 when rotating. The first stopper 111 is located at one end of the housing 110 close to the galvanometer lens 220, and the gap between the housing 110 and the galvanometer lens 220 is fully utilized to achieve installation, and the stopper function of the galvanometer lens 220 is realized without increasing the volume of the galvanometer motor.

Specifically, please refer to FIG. 1 , the rotation areas of the first stopper 111 and the galvanometer lens 220 are staggered on one end surface of the housing 110. In other words, the galvanometer lens 220 will not touch the first stopper 111 during its rotation, so the galvanometer lens 220 does not need to be staggered on the axis of the rotating shaft 210 to avoid the first stopper 111. The length of the end of the rotating shaft 210 exposed from the housing 110 can be shortened as much as possible to meet the installation of the galvanometer lens 220, so as to reduce the length of the galvanometer motor.

It can be understood that in other embodiments, the first limit member 111 and the second limit member 212 can also be located inside the shell 110, but the diameter of the shell 110 will be increased, or they can be located at one end of the shell 110 away from the galvanometer lens 220, but the length of the galvanometer motor will be increased.

Specifically, please refer to FIG. 1 , the number of the first limit members 111 is two. The two first limit members 111 are arranged opposite to each other, and the second limit members 212 correspond to the first limit members 111 one by one. There are also two second limit members 212, and each second limit member 212 is limitedly matched with the corresponding first limit member 111. In this way, the limiting force applied by the housing 110 to the rotating shaft 210 is two, which can achieve a more uniform and reasonable force on the rotating shaft 210 and improve the reliability of the galvanometer motor.

Optionally, the two first limiting members 111 are arranged opposite to each other, so that the limiting forces exerted on the rotating shaft 210 are symmetrical, which is conducive to the stable rotation of the rotating shaft 210 within a small angle.

Specifically, referring to FIG. 1 and FIG. 2 , the first limit member 111 is two limit blocks 112 disposed at one end of the housing 110 close to the galvanometer lens 220, and the two limit blocks 112 are disposed at intervals. The second limit member 212 contacts one of the limit blocks 112 when the shaft 210 rotates to the first limit position, thereby blocking the shaft 210 from further rotating. The second limit member 212 contacts the other limit block 112 when the shaft 210 rotates to the second limit position, thereby blocking the shaft 210 from further rotating, so that the shaft 210 rotates at a limited angle between the first limit position and the second limit position.

A limiting groove 113 is formed between the two limiting blocks 112 , and the second limiting member 212 rotates within a limited angle in the limiting groove 113 .

Furthermore, the first limiting member 111 further includes a connecting wall 114 protruding from one end of the housing 110 , and two ends of the connecting wall 114 are respectively connected to ends of the two limiting blocks 112 away from the rotating shaft 210 .

In this embodiment, the second limiting member 212 is a limiting pin.

In another specific embodiment of the present embodiment, please refer to Figures 2 and 3, the galvanometer motor further includes two bearings 400. The two bearings 400 are respectively mounted at both ends of the housing 110 and sleeved on the shaft 210, providing rotation support for the shaft 210 from both ends of the shaft 210, improving the support effect, and making the shaft 210 and the galvanometer lens 220 rotate more smoothly.

The driving coil 120 , the magnetic pole 211 , the sensor plate 300 and the magnetic sensor 310 are all located between the two bearings 400 , so that the galvanometer motor has a compact structure.

Specifically, referring to FIG. 3 , the driving coil 120 is directly surrounded and fixed on the inner wall of the housing 110 .

For example, the driving coil 120 is bonded and fixed to the inner wall of the housing 110 without the need for other auxiliary mounting structures, thereby avoiding increasing the diameter of the housing 110 .

The interior of the housing 110 forms a relatively closed cylindrical cavity, and the pair of magnetic poles 211 is cylindrical and arranged in the cylindrical cavity, with matching shapes and compact structure. In the axial direction of the rotating shaft 210, the length of the pair of magnetic poles 211 is equal to the length of the driving coil 120, or the difference is less than 1mm. Most of the side areas of the radially magnetized pair of magnetic poles 211 are used to interact with the electromagnetic force of the driving coil 120 to maximize the area of interaction, so that the diameter of the housing 110 and the pair of magnetic poles 211 can be designed to be smaller.

The sensor plate 300 is mounted on the inner side of the end of the housing 110 away from the galvanometer lens 220. The sensor plate 300 is a circular plate. The middle of the sensor plate 300 has a through hole for the end of the rotating shaft 210 to pass through, so that the end of the rotating shaft 210 is mounted on the bearing 400. The projections of the sensor plate 300 and the pair of magnetic poles 211 in the axial direction of the rotating shaft 210 are basically overlapped. The magnetic sensor 310 is mounted on the side of the sensor plate 300 close to the magnetic pole 211. The magnetic sensor 310 is arranged opposite to the tail of the pair of magnetic poles 211, and the distance is small, which improves the detection accuracy of the magnetic sensor 310 and improves the reliability of the galvanometer motor.

In another specific embodiment of the present embodiment, referring to FIG. 1 and FIG. 2 , the housing 110 includes a housing body 115 and a tail cover 116. One end of the housing body 115 is open so that the driving coil 120 and the rotating shaft 210 can be installed inside the housing body 115. The tail cover 116 is detachably mounted on the open end of the housing body 115, the sensor board 300 is fixed on the inner side of the tail cover 116, and one end of the rotating shaft 210 can be rotatably mounted on the tail cover 116 through a bearing 400.

Specifically, the tail cover 116 has a wire outlet hole 117, and the terminal 121 of the drive coil 120 and the lead 320 of the sensor board 300 are electrically connected to the external drive board through the wire outlet hole 117. The drive board is used to provide alternating current to the drive coil 120 and to obtain the output signal of the magnetic sensor 310. In this way, the drive board is placed outside the galvanometer motor to avoid occupying the internal space of the housing 110, further compressing the volume of the housing 110, and making the structure of the galvanometer motor more compact.

The number of the outlet holes 117 may be one, and the terminal 121 of the drive coil 120 and the lead 320 of the sensor board 300 are both led out of the galvanometer motor through the same outlet hole 117. The number of the outlet holes 117 may also be two, and the terminal 121 of the drive coil 120 and the lead 320 of the sensor board 300 are respectively led out of the galvanometer motor through different outlet holes 117.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. A galvanometer motor, comprising:

A stator including a housing and a driving coil installed in the housing;

The rotor comprises a rotating shaft and a vibrating mirror lens, the middle part of the rotating shaft is a pair of magnetic poles magnetized in the radial direction, two ends of the rotating shaft are rotatably arranged in the shell, and one end of the rotating shaft extends to the outside of the shell and is connected with the vibrating mirror lens;

The sensor plate is fixed on the inner wall of the shell and is positioned at one end of the shell far away from the vibrating mirror lens, and is provided with a magnetic sensor which is used for sensing magnetic field signals generated by a pair of magnetic poles so as to acquire the absolute positions of the rotating shaft and the vibrating mirror lens;

The shell is provided with a first limiting part, the rotating shaft is connected with a second limiting part, the first limiting part is in limiting fit with the second limiting part, so that the rotating shaft rotates between a first limiting position and a second limiting position, and a central angle formed by the first limiting position and the second limiting position and the axis of the rotating shaft is smaller than 90 degrees;

The output signal of the magnetic sensor and the angle of the rotating shaft are in a sine function relationship, and the angle of the rotating shaft between the first limit position and the second limit position corresponds to a monotonic interval of the sine function relationship; when the rotating shaft is at the initial position, the junction of the magnetic sensor and the pair of magnetic poles is positioned in the same radial direction of the rotating shaft.

2. The galvanometer motor of claim 1, wherein: the first limiting parts are located on the outer wall of one end, close to the vibrating mirror lens, of the shell, the number of the first limiting parts is two, the two first limiting parts are oppositely arranged, and the second limiting parts correspond to the first limiting parts one by one.

3. The galvanometer motor of claim 1, wherein: the first limiting piece is two limiting blocks which are arranged on one end part of the shell and close to the vibrating mirror lens, the two limiting blocks are arranged at intervals, the second limiting piece is in contact with one limiting block when the rotating shaft rotates to the first limiting position, and the second limiting piece is in contact with the other limiting block when the rotating shaft rotates to the second limiting position.

4. The galvanometer motor of claim 1, wherein: the number of the magnetic sensors is more than two, and the phase difference between any two magnetic sensors is more than 0 DEG and less than 180 deg.

5. The galvanometer motor of claim 1, wherein: the magnetic sensor comprises a differential Hall sensor group, the differential Hall sensor group comprises two differential Hall sensing units, and the phase difference between the two differential Hall sensing units is 180 degrees.

6. The galvanometer motor of claim 1, wherein: the shell comprises a shell body and a tail cover, one end of the shell body is open, the tail cover is detachably arranged at the open end of the shell body, the sensor plate is fixed on the inner side of the tail cover, and one end of the rotating shaft is rotatably arranged at the tail cover.

7. The galvanometer motor of claim 1, wherein: the driving coil is wound to form a hollow winding.

8. The galvanometer motor according to any one of claims 1 to 7, wherein: the vibrating mirror motor further comprises two bearings, the bearings are mounted at two ends of the shell and are sleeved with the rotating shaft, and the driving coil, the magnetic poles, the sensor plate and the magnetic sensor are located between the two bearings.