Single-phase brushless galvanometer motor and working method thereof

Abstract

The invention discloses a single-phase brushless galvanometer motor and a working method thereof, and relates to the technical field of motor structures. Comprising a stator winding fixed on an inner ring of a stator, an outer ring of the stator is bonded with a casing, the left end of the stator is tightly attached to an inner diameter limiting step of the casing, and the front end of the casing is matched with a boss of a front end cover and is locked through a screw; a front bearing is placed in a bearing chamber of the front end cover; the rear end of the machine shell is attached to the rear end cover, the rear end cover and the rear cover plate are locked through screws, and a rear bearing is placed in a bearing chamber of the rear end cover. Existing parts are fully utilized, magnetic bar limiting and front shaft limiting are utilized to achieve magnetizing positioning and assembly installation positioning, front shaft limiting and front cover limiting grooves are utilized to achieve motor installation positioning and operation limiting, a magnetic chip is applied to motor position feedback, and the axial length of the motor is shortened by 10-15 mm.

Description

Technical Field

[0001] The present invention relates to the technical field of motor structures, and in particular to a single-phase brushless galvanometer motor and a working method thereof. Background Art

[0002] The galvanometer motor is an excellent vector scanning device. It is a special swing motor. The basic principle is that the energized coil generates torque in the magnetic field. However, unlike the rotating motor, the rotor is added with a reset torque through a mechanical spring or electronic method. The magnitude is proportional to the angle of the rotor's deviation from the equilibrium position. When a certain current is passed through the coil and the rotor deflects to a certain angle, the electromagnetic torque is equal to the restoring torque. Therefore, it cannot rotate like an ordinary motor, but can only deflect. The deflection angle is proportional to the current, just like an ammeter, so the galvanometer is also called an ammeter galvanometer motor. The galvanometer system is a high-precision, high-speed servo control system composed of a drive board and a high-speed swing motor. It is mainly used in laser marking, laser engraving, stage lighting control, laser drilling, and dot matrix laser medical beauty industries, so the accuracy of the galvanometer is required to be high.

[0003] Chinese patent CN201911025276.4 describes a galvanometer motor, including a stator assembly, a rotor assembly rotating relative to the stator assembly, and a feedback device for providing feedback on the position of the rotor assembly; the stator assembly includes a housing, a coil fixed to the inner wall of the housing, and a stopper fixed to the upper end of the housing; the rotor assembly includes a shaft assembly passing through the coil and a lens clamp fixed to the upper end of the shaft assembly; a lens slot is provided at the upper end of the lens clamp. This motor has the following disadvantages: 1: The limit structure uses a limit pin + limit block, which has a complex structure, and the installation direction of the galvanometer must be parallel to the limit pin, which limits the installation angle of the lens. The increase in parts also increases the processing time and assembly process steps, increasing the cost. At the same time, the structure also occupies axial space, making the motor longer, and the limit pin also increases the rotor mass and moment of inertia, causing a waste of the motor's load capacity.

[0004] 2: The position feedback adopts the photocell sensor used in traditional analog galvanometers. This sensor needs to be used with an LED light source and a shading sheet, which takes up a lot of space. The axial space of the encoder structure is close to 20mm or more, which increases the length and weight of the entire motor. In addition, the shading sheet is small in size, making it difficult to process the shaft and install the shading sheet. Summary of the invention

[0005] The present invention provides a single-phase brushless galvanometer motor with a simple structure, compact space and light weight and a working method thereof. The magnetization positioning and component installation positioning are realized by using a magnetic bar limit and a front shaft limit, the motor installation positioning and operation limiting are realized by using a front shaft limit and a front cover limit groove, and a magnetic encoding chip is applied to the motor position feedback, thereby greatly shortening the axial length of the motor.

[0006] A single-phase brushless galvanometer motor comprises a stator winding fixed to an inner ring of a stator, an outer ring of the stator is bonded to a casing, a left end of the stator is closely attached to an inner diameter limiting step of the casing, a front end of the casing is matched with a boss of a front cover and is locked by screws; a front bearing is placed in a bearing chamber of the front cover; a rear end of the casing is fitted with a rear cover, the rear cover is locked with a rear cover plate by screws, and a rear bearing is placed in the bearing chamber of the rear cover; The inner diameter of the rear end cover matches the outer circle clearance of the PCB board, an induction magnet is arranged in the cavity of the rear end cover, the induction magnet is bonded inside the induction magnet seat, the induction magnet seat is threadedly locked with one end of the rear axle, and the other end of the rear axle is equipped with a magnetic rod by virtue of the inner and outer diameter matching, and the magnetic rod matches the front axle; a flat gasket is arranged between the outer diameter boss of the front axle and the inner ring of the front bearing.

[0007] Preferably, the double flattened portion of the outer circle of the front axle of the present invention and the limiting groove in the middle of the front end cover form a limiting structure, so that the running angle of the motor is limited within the range of the limiting groove.

[0008] Preferably, the inner ring of the stator of the present invention is provided with two screw holes, and the stator winding is symmetrically arranged with the two screw holes.

[0009] Preferably, the ends of the front shaft of the present invention that match the magnetic rod are respectively processed with steps for assembly, and the assembly and magnetization positioning are based on the steps.

[0010] Preferably, a magnetic coding chip is attached to the center of the PCB board of the present invention, and a connector is welded to the top of the PCB board.

[0011] A working method of a single-phase brushless galvanometer motor comprises the following steps: firstly, a current is loaded on a stator winding to generate a clockwise / counterclockwise magnetic field, the magnetic field interacts with the magnetic field of a magnetic bar to generate a clockwise / counterclockwise torque, and the magnitude of the torque is proportional to the magnitude of the current; the torque drives the rear shaft and the front shaft, and then the two shafts perform reciprocating polarized rotational motion under the constraints of the front bearing and the rear bearing, wherein the double flat parts of the front shaft and the limiting holes of the front end cover constitute a motion limiting range, and the motion range of the entire rotor assembly is constrained by the limiting holes; the rear shaft drives the induction magnet seat to rotate under the action of the torque, and then the induction magnet seat drives the induction magnet bonded in the seat, the magnetic encoding chip faces the rotating induction magnet, and senses the absolute angle position of the rotor, and then the absolute angle position information is sent to an external driver through a PCB board and a connector; the driver calculates a new current for the stator winding according to the current absolute angle position information, and repeats this process.

[0012] The present invention adopts the above technical solution and has the following advantages compared with the prior art: The galvanometer motor provided by the present invention makes full use of existing components, realizes magnetization positioning and component installation positioning by using the magnetic bar limit and the front shaft limit 2, realizes motor installation positioning and operation limiting by using the front shaft limit 1 and the front cover limit groove, and applies the magnetic encoding chip to the motor position feedback, so that the axial length of the motor is shortened by 10-15mm. The specific advantages are described as follows: 1: The galvanometer motor structure of the present invention solves the problem of rotor magnetization and positioning. The rotor can be magnetized before installation (relying on the magnetic rod limit) or magnetized after installation (relying on the front shaft limit 1).

[0013] 2: In the galvanometer motor structure of the present invention, each component of the rotor assembly has a step limiter, the assembly and the whole machine installation process is super simple, and the step limiter combination of each component forms a fool-proof structure to a certain extent, the installation will not go wrong, and it is very easy to mass produce.

[0014] 3: Compared with the rotor in the prior art, which has the problem of limit pins and heavy rotor weight, the rotor of the present invention eliminates the limit pins and processes steps and through holes on the rotating shaft, thereby reducing the weight and moment of inertia of the rotor assembly and simultaneously improving the load capacity of the motor.

[0015] 4: Compared with the prior art, the limiting structure requires two components, a limiting cover and a limiting pin, to realize the limiting function. The limiting structure provided by the present invention is integrated into the front end cover and the front axle, saving two components. The axial space is less than 1 mm, and the rotor front axle step and the front end cover limit form an anti-mistake structure. The installation of the whole machine is very simple, thereby reducing the weight of the motor, shortening the length of the motor, and reducing the cost.

[0016] 5: Compared with the prior art where the galvanometer needs to be installed parallel to the limit pin, the limit structure of the galvanometer motor of the present invention eliminates the positioning pin and relies on the front shaft and the front cover to keep the rotor in the optimal output operating angle range. The installation angle of the galvanometer has no effect on the motor output, and the lens installation angle can be adjusted as needed, reducing the difficulty of use.

[0017] 6. The feedback device of the prior art uses a photocell sensor, which has a complex structure and occupies an axial space of more than 20 mm. The feedback device of the galvanometer motor of the present invention uses a magnetic encoder, which has a simple structure and an axial space of less than 10 mm, thereby shortening the motor length and reducing weight and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a front view of the galvanometer motor of the present invention; Figure 2 for Figure 1 Middle JJ section view; Figure 3 It is a structural schematic diagram of the stator assembly of the present invention; Figure 4 It is a schematic diagram of the explosion state of the rotor assembly of the present invention; Figure 5 It is a schematic diagram of the limiting structure of the front end cover of the present invention.

[0019] Among them: 11, casing; 12, stator; 13, stator winding; 21, front axle; 22, magnetic rod; 23, rear axle; 24, induction magnet seat; 25, induction magnet; 31, front cover; 32, rear cover; 33, rear cover plate; 41, front bearing; 42, rear bearing; 51, PCB board; 52, magnetic encoding chip; 53, connector; 61, front cover screw; 62, PCB screw; 63, rear cover screw; 64, flat washer. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is described in detail below with reference to the accompanying drawings: The galvanometer motor structure of the present invention comprises a stator assembly composed of a housing 11, a stator 12 and a stator winding 13; a rotor assembly composed of a front shaft 21, a magnetic rod 22, a rear shaft 23, an induction magnet seat 24 and an induction magnet 25; a front and rear end covers composed of a front end cover 31, a rear end cover 32 and a rear cover plate 33; a front and rear bearings composed of a front bearing 41 and a rear bearing 42; a magnetically encoded PCB assembly composed of a PCB board 51, a magnetically encoded chip 52 and a connector 53; and screw gasket auxiliary materials composed of a front end cover screw 61, a PCB screw 62, a rear end cover screw 63 and a flat washer 64.

[0021] like Figure 1-Figure 5As shown, the stator winding 13 is fixed to the inner ring of the stator 12, and the two screw holes of the stator 12 are symmetrically arranged through the tooling. The outer ring of the stator 12 is bonded to the inner diameter of the casing 11, and the left end of the stator 12 is close to the inner diameter limit step of the casing 11. The front end of the casing 11 cooperates with the boss of the front cover 31 and is locked by screws 61. The front bearing 41 is placed in the bearing chamber of the front cover 31. The rear end of the casing 11 fits with the rear cover 32, and the rear cover 32 is locked with the rear cover plate 33 by screws 63. The rear bearing 42 is placed in the bearing chamber of the rear cover 32. The double flat position of the outer circle of the front shaft 21 and the limit groove in the middle of the front cover 31 form a limit structure, so that the running angle of the motor is limited to Within the range of the limiting groove, the outer diameter boss of the front shaft 21 and the inner ring of the front bearing 41 rely on the flat gasket 64 to offset the axial clearance and reduce the radial vibration of the motor. The inner diameter of the rear end of the rotor front shaft 21 and the outer circle of the front end of the magnetic rod 22 are both processed with steps, which are assembled and magnetized for positioning. The rear end of the magnetic rod 22 and the rear shaft 23 are assembled by matching the inner and outer diameters. The rear shaft 23 and the induction magnet seat 24 are locked by threads. The induction magnet seat 24 is bonded with an induction magnet 25. The outer circle of the PCB board 51 and the inner diameter of the rear end cover 32 are clearance matched and locked by screws 62. A magnetic encoding chip 52 is attached to the center of the PCB board 51, and a connector 53 is welded on the top of the PCB board 51.

[0022] First, the external driver gives the position information given by the user Figure 3 The stator winding 13 is loaded with current to generate a clockwise / counterclockwise magnetic field. Figure 2 The magnetic field of the magnetic bar 22 in the center of the motor generates a clockwise / counterclockwise torque, and the torque is proportional to the current. Since the rotor assembly of the galvanometer motor has no limit pins and the front axle 21 is double-sided to reduce weight, the entire rotor assembly is lighter than the rotor of a traditional galvanometer motor of the same length. Therefore, the same current can drive a larger galvanometer. The torque drives Figure 2 The rear shaft 23 and the front shaft 21 in the rotor assembly then perform reciprocating polarized rotational motion together under the constraints of the front bearing 41 and the rear bearing 42, wherein the double flat position of the front shaft 21 and the limiting hole of the front end cover 31 constitute a motion limiting range, and the motion range of the entire rotor assembly is constrained in the limiting hole to prevent the galvanometer from exceeding the motion range and causing damage to the equipment. The rear shaft 22 in the rotor assembly is driven by the torque Figure 2 The induction magnet seat 24 in the middle rotates, and then the induction magnet seat 24 drives the induction magnet 25 bonded in the seat, Figure 2 The middle magnetic encoder chip 52 faces the rotating induction magnet to sense the absolute angular position of the rotor, and then sends the absolute angular position information to the external driver through the PCB board 51 and the connector 53. The absolute angular position signal is a pure digital SPI signal, which has better anti-interference than the analog current signal output by the traditional photocell. The external driver calculates the new current for the stator stator winding 13 according to the current angle information, and repeats this process.

[0023] Combination Figure 4 The single-phase brushless galvanometer motor provided by the present invention has a simple structure, compact space, and is lightweight. It makes full use of existing components, utilizes magnetic bar limiters and front shaft limiters 2 to realize magnetization positioning and component installation positioning, utilizes front shaft limiters 1 and front cover limiter grooves to realize motor installation positioning and operation limiting, and applies magnetic encoding chips to motor position feedback, thereby shortening the axial length of the motor by 10-15mm.

Claims

1. A single-phase brushless galvanometer motor, characterized in that The invention comprises a stator winding (13) fixed to the inner ring of the stator (12); the outer ring of the stator (12) is bonded to the housing (11); the left end of the stator (12) is closely attached to the inner diameter limiting step of the housing 11; the front end of the housing (11) is matched with the boss of the front end cover (31) and is locked by means of screws (61); a front bearing (41) is placed in the bearing chamber of the front end cover (31); the rear end of the housing (11) is fitted with the rear end cover (32); the rear end cover (32) is locked with the rear cover plate (33) by means of screws (63); and a rear bearing (42) is placed in the bearing chamber of the rear end cover (32); The inner diameter of the rear end cover (32) is matched with the outer circle clearance of the PCB board (51), the induction magnet (25) is arranged in the cavity of the rear end cover (32), the induction magnet (25) is bonded to the inside of the induction magnet seat (24), the induction magnet seat (24) is threadedly locked with one end of the rear shaft (23), the other end of the rear shaft (23) is equipped with a magnetic rod (22) by virtue of the inner and outer diameter matching, the magnetic rod (22) and the front shaft (21) are matched with each other; the outer diameter boss of the front shaft (21) and the inner ring of the front bearing (41) are provided with a flat gasket (64).

2. The single-phase brushless galvanometer motor according to claim 1, characterized in that The double flattened portion of the outer circle of the front shaft (21) and the limiting groove in the middle of the front end cover (31) form a limiting structure, so that the running angle of the motor is limited within the range of the limiting groove.

3. The single-phase brushless galvanometer motor according to claim 1, characterized in that Two screw holes are provided on the inner ring of the stator (12), and the stator winding (13) is symmetrically arranged around the two screw holes.

4. The single-phase brushless galvanometer motor according to claim 1, characterized in that The ends of the front shaft (21) and the magnetic rod (22) that match each other are respectively processed with steps for assembly, and the assembly and magnetization positioning are performed by means of the steps.

5. The single-phase brushless galvanometer motor according to claim 1, characterized in that A magnetic coding chip (52) is attached to the center of the PCB board (51), and a connector (53) is welded to the top of the PCB board (51).

6. A working method of a single-phase brushless galvanometer motor according to any one of claims 1 to 5, characterized in that: First, a current is applied to the stator winding (13) to generate a clockwise / counterclockwise magnetic field, which interacts with the magnetic field of the magnetic bar (22) to generate a clockwise / counterclockwise torque, the magnitude of which is proportional to the magnitude of the current; the torque drives the rear shaft (23) and the front shaft (21), which then perform reciprocating polarized rotational motion together under the constraints of the front bearing (41) and the rear bearing (42), wherein the double flat part of the front shaft (21) and the limiting hole of the front end cover (31) constitute a motion limiting range, limiting the motion of the entire rotor assembly The range is constrained by the limit hole; the rear shaft (22) drives the induction magnet seat (24) to rotate under the action of the rotational torque, and then the induction magnet seat (24) drives the induction magnet (25) bonded to the seat, and the magnetic encoding chip (52) faces the rotating induction magnet to sense the absolute angle position of the rotor, and then sends the absolute angle position information to the external driver through the PCB board (51) and the connector (53); the driver calculates a new current for the stator winding (13) according to the current absolute angle position information, and repeats this process.

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